Changeset f5a51db

benchmark/io/http/Makefile.am

r97c215f	rf5a51db
21	21	include $(top_srcdir)/tools/build/cfa.make
22	22
23		AM_CFLAGS = -O2 -Wall -Wextra -I$(srcdir) -lrt -pthread # -Werror
	23	AM_CFLAGS = -O3 -Wall -Wextra -I$(srcdir) -lrt -pthread # -Werror
24	24	AM_CFAFLAGS = -quiet -nodebug
25	25	AM_LDFLAGS = -quiet -nodebug

benchmark/io/http/main.cfa

-                      r97c215f
+                      rf5a51db
 #define __USE_GNU
+#define _GNU_SOURCE
 #include <errno.h>
 …
 #include <unistd.h>
 extern "C" {
+        #include <sched.h>
         #include <signal.h>
         #include <sys/socket.h>
 …
         (this.self){ "Server Cluster", options.clopts.params };
+        cpu_set_t fullset;
+        CPU_ZERO(&fullset);
+        int ret = sched_getaffinity(getpid(), sizeof(fullset), &fullset);
+        if( ret != 0 ) abort | "sched_getaffinity failed with" | errno | strerror( errno );
+        int cnt = CPU_COUNT(&fullset);
         this.procs = alloc(options.clopts.nprocs);
         for(i; options.clopts.nprocs) {
                 (this.procs[i]){ "Benchmark Processor", this.self };
+                int c = 0;
+                int n = 1 + (i % cnt);
+                for(int j = 0; j < CPU_SETSIZE; j++) {
+                        if(CPU_ISSET(j, &fullset)) n--;
+                        if(n == 0) {
+                                c = j;
+                                break;
+                        }
+                }
+                cpu_set_t localset;
+                CPU_ZERO(&localset);
+                CPU_SET(c, &localset);
+                ret = pthread_setaffinity_np(this.procs[i].kernel_thread, sizeof(localset), &localset);
+                if( ret != 0 ) abort | "sched_getaffinity failed with" | ret | strerror( ret );
                 #if !defined(__CFA_NO_STATISTICS__)
 …
         int waited = 0;
         for() {
+                ret = bind( server_fd, (struct sockaddr *)&address, sizeof(address) );
+                int sockfd = server_fd;
+                __CONST_SOCKADDR_ARG addr;
+                addr.__sockaddr__ = (struct sockaddr *)&address;
+                socklen_t addrlen = sizeof(address);
+                ret = bind( sockfd, addr, addrlen );
                 if(ret < 0) {
                         if(errno == EADDRINUSE) {

doc/theses/thierry_delisle_PhD/thesis/Makefile

r97c215f	rf5a51db
48	48	## Define the documents that need to be made.
49	49	all: thesis.pdf
50		thesis.pdf: ${TEXTS} ${FIGURES} ${PICTURES} thesis.tex glossary.tex local.bib
	50	thesis.pdf: ${TEXTS} ${FIGURES} ${PICTURES} thesis.tex glossary.tex local.bib ../../../LaTeXmacros/common.tex ../../../LaTeXmacros/common.sty
51	51
52	52	DOCUMENT = thesis.pdf

doc/theses/thierry_delisle_PhD/thesis/fig/base.fig

-                      r97c215f
+                      rf5a51db
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+3 0 1 0 0 50 -1 20 0.000 1 0.0000 6600 5175 20 20 6600 5175 6620 5175
 -6
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 …
 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 2
 2475 3000 2475
+3 0 1 0 7 50 -1 -1 0.000 0 0 0 0 0 7
+5210 3150 4950 2850 4950 2700 5210 2850 5470 3150 5470
+5210
+3 0 1 0 7 50 -1 -1 0.000 0 0 0 0 0 7
+5210 4350 4950 4050 4950 3900 5210 4050 5470 4350 5470
+5210
+3 0 1 0 7 50 -1 -1 0.000 0 0 0 0 0 7
+5210 5550 4950 5250 4950 5100 5210 5250 5470 5550 5470
+5210
 2 -1 50 -1 0 12 0.0000 2 135 630 2100 3075 Threads\001
 2 -1 50 -1 0 12 0.0000 2 165 450 2100 2850 Ready\001
 …
 1 -1 50 -1 0 11 0.0000 2 135 180 2700 3550 TS\001
 1 -1 50 -1 0 11 0.0000 2 135 180 2700 2650 TS\001
+2 -1 50 -1 0 12 0.0000 2 135 900 2100 5175 Processors\001

doc/theses/thierry_delisle_PhD/thesis/glossary.tex

-                      r97c215f
+                      rf5a51db
 \textit{Synonyms : User threads, Lightweight threads, Green threads, Virtual threads, Tasks.}
+}
+\longnewglossaryentry{rmr}
+{name={remote memory reference}}
+{
+}

doc/theses/thierry_delisle_PhD/thesis/text/core.tex

-                      r97c215f
+                      rf5a51db
 \section{Design}
 In general, a na\"{i}ve \glsxtrshort{fifo} ready-queue does not scale with increased parallelism from \glspl{hthrd}, resulting in decreased performance. The problem is adding/removing \glspl{thrd} is a single point of contention. As shown in the evaluation sections, most production schedulers do scale when adding \glspl{hthrd}. The common solution to the single point of contention is to shard the ready-queue so each \gls{hthrd} can access the ready-queue without contention, increasing performance.
+In general, a na\"{i}ve \glsxtrshort{fifo} ready-queue does not scale with increased parallelism from \glspl{hthrd}, resulting in decreased performance. The problem is adding/removing \glspl{thrd} is a single point of contention. As shown in the evaluation sections, most production schedulers do scale when adding \glspl{hthrd}. The solution to this problem is to shard the ready-queue : create multiple sub-ready-queues that multiple \glspl{hthrd} can access and modify without interfering.
+\subsection{Sharding} \label{sec:sharding}
+An interesting approach to sharding a queue is presented in \cit{Trevors paper}. This algorithm presents a queue with a relaxed \glsxtrshort{fifo} guarantee using an array of strictly \glsxtrshort{fifo} sublists as shown in Figure~\ref{fig:base}. Each \emph{cell} of the array has a timestamp for the last operation and a pointer to a linked-list with a lock. Each node in the list is marked with a timestamp indicating when it is added to the list. A push operation is done by picking a random cell, acquiring the list lock, and pushing to the list. If the cell is locked, the operation is simply retried on another random cell until a lock is acquired. A pop operation is done in a similar fashion except two random cells are picked. If both cells are unlocked with non-empty lists, the operation pops the node with the oldest timestamp. If one of the cells is unlocked and non-empty, the operation pops from that cell. If both cells are either locked or empty, the operation picks two new random cells and tries again.
+Before going into the design of \CFA's scheduler proper, I want to discuss two sharding solutions which served as the inspiration scheduler in this thesis.
+\subsection{Work-Stealing}
+As I mentioned in \ref{existing:workstealing}, a popular pattern shard the ready-queue is work-stealing. As mentionned, in this pattern each \gls{proc} has its own ready-queue and \glspl{proc} only access each other's ready-queue if they run out of work.
+The interesting aspect of workstealing happen in easier scheduling cases, \ie enough work for everyone but no more and no load balancing needed. In these cases, work-stealing is close to optimal scheduling: it can achieve perfect locality and have no contention.
+On the other hand, work-stealing schedulers only attempt to do load-balancing when a \gls{proc} runs out of work.
+This means that the scheduler may never balance unfairness that does not result in a \gls{proc} running out of work.
+Chapter~\ref{microbench} shows that in pathological cases this problem can lead to indefinite starvation.
+Based on these observation, I conclude that \emph{perfect} scheduler should behave very similarly to work-stealing in the easy cases, but should have more proactive load-balancing if the need arises.
+\subsection{Relaxed-Fifo}
+An entirely different scheme is to create a ``relaxed-FIFO'' queue as in \todo{cite Trevor's paper}. This approach forgos any ownership between \gls{proc} and ready-queue, and simply creates a pool of ready-queues from which the \glspl{proc} can pick from.
+\Glspl{proc} choose ready-queus at random, but timestamps are added to all elements of the queue and dequeues are done by picking two queues and dequeing the oldest element.
+The result is a queue that has both decent scalability and sufficient fairness.
+The lack of ownership means that as long as one \gls{proc} is still able to repeatedly dequeue elements, it is unlikely that any element will stay on the queue for much longer than any other element.
+This contrasts with work-stealing, where \emph{any} \gls{proc} busy for an extended period of time results in all the elements on its local queue to have to wait. Unless another \gls{proc} runs out of work.
+An important aspects of this scheme's fairness approach is that the timestamps make it possible to evaluate how long elements have been on the queue.
+However, another major aspect is that \glspl{proc} will eagerly search for these older elements instead of focusing on specific queues.
+While the fairness, of this scheme is good, it does suffer in terms of performance.
+It requires very wide sharding, \eg at least 4 queues per \gls{hthrd}, and the randomness means locality can suffer significantly and finding non-empty queues can be difficult.
+\section{\CFA}
+The \CFA is effectively attempting to merge these two approaches, keeping the best of both.
+It is based on the
 \begin{figure}
         \centering
         \input{base.pstex_t}
         \caption[Relaxed FIFO list]{Relaxed FIFO list \smallskip\newline List at the base of the scheduler: an array of strictly FIFO lists. The timestamp is in all nodes and cell arrays.}
+        \caption[Base \CFA design]{Base \CFA design \smallskip\newline A list of sub-ready queues offers the sharding, two per \glspl{proc}. However, \glspl{proc} can access any of the sub-queues.}
         \label{fig:base}
 \end{figure}
-\subsection{Finding threads}
-Once threads have been distributed onto multiple queues, identifying empty queues becomes a problem. Indeed, if the number of \glspl{thrd} does not far exceed the number of queues, it is probable that several of the cell queues are empty. Figure~\ref{fig:empty} shows an example with 2 \glspl{thrd} running on 8 queues, where the chances of getting an empty queue is 75\% per pick, meaning two random picks yield a \gls{thrd} only half the time. This scenario leads to performance problems since picks that do not yield a \gls{thrd} are not useful and do not necessarily help make more informed guesses.
-\begin{figure}
-        \centering
-        \input{empty.pstex_t}
-        \caption[``More empty'' Relaxed FIFO list]{``More empty'' Relaxed FIFO list \smallskip\newline Emptier state of the queue: the array contains many empty cells, that is strictly FIFO lists containing no elements.}
-        \label{fig:empty}
-\end{figure}
+There are several solutions to this problem, but they ultimately all have to encode if a cell has an empty list. My results show the density and locality of this encoding is generally the dominating factor in these scheme. Classic solutions to this problem use one of three techniques to encode the information:
+% The common solution to the single point of contention is to shard the ready-queue so each \gls{hthrd} can access the ready-queue without contention, increasing performance.
+\paragraph{Dense Information} Figure~\ref{fig:emptybit} shows a dense bitmask to identify the cell queues currently in use. This approach means processors can often find \glspl{thrd} in constant time, regardless of how many underlying queues are empty. Furthermore, modern x86 CPUs have extended bit manipulation instructions (BMI2) that allow searching the bitmask with very little overhead compared to the randomized selection approach for a filled ready queue, offering good performance even in cases with many empty inner queues. However, this technique has its limits: with a single word\footnote{Word refers here to however many bits can be written atomically.} bitmask, the total amount of ready-queue sharding is limited to the number of bits in the word. With a multi-word bitmask, this maximum limit can be increased arbitrarily, but the look-up time increases. Finally, a dense bitmap, either single or multi-word, causes additional contention problems that reduces performance because of cache misses after updates. This central update bottleneck also means the information in the bitmask is more often stale before a processor can use it to find an item, \ie mask read says there are available \glspl{thrd} but none on queue when the subsequent atomic check is done.
+% \subsection{Sharding} \label{sec:sharding}
+% An interesting approach to sharding a queue is presented in \cit{Trevors paper}. This algorithm presents a queue with a relaxed \glsxtrshort{fifo} guarantee using an array of strictly \glsxtrshort{fifo} sublists as shown in Figure~\ref{fig:base}. Each \emph{cell} of the array has a timestamp for the last operation and a pointer to a linked-list with a lock. Each node in the list is marked with a timestamp indicating when it is added to the list. A push operation is done by picking a random cell, acquiring the list lock, and pushing to the list. If the cell is locked, the operation is simply retried on another random cell until a lock is acquired. A pop operation is done in a similar fashion except two random cells are picked. If both cells are unlocked with non-empty lists, the operation pops the node with the oldest timestamp. If one of the cells is unlocked and non-empty, the operation pops from that cell. If both cells are either locked or empty, the operation picks two new random cells and tries again.
+\begin{figure}
+        \centering
+        \vspace*{-5pt}
+        {\resizebox{0.75\textwidth}{!}{\input{emptybit.pstex_t}}}
+        \vspace*{-5pt}
+        \caption[Underloaded queue with bitmask]{Underloaded queue with bitmask indicating array cells with items.}
+        \label{fig:emptybit}
+% \begin{figure}
+%       \centering
+%       \input{base.pstex_t}
+%       \caption[Relaxed FIFO list]{Relaxed FIFO list \smallskip\newline List at the base of the scheduler: an array of strictly FIFO lists. The timestamp is in all nodes and cell arrays.}
+%       \label{fig:base}
+% \end{figure}
+        \vspace*{10pt}
+        {\resizebox{0.75\textwidth}{!}{\input{emptytree.pstex_t}}}
+        \vspace*{-5pt}
+        \caption[Underloaded queue with binary search-tree]{Underloaded queue with binary search-tree indicating array cells with items.}
+        \label{fig:emptytree}
+% \subsection{Finding threads}
+% Once threads have been distributed onto multiple queues, identifying empty queues becomes a problem. Indeed, if the number of \glspl{thrd} does not far exceed the number of queues, it is probable that several of the cell queues are empty. Figure~\ref{fig:empty} shows an example with 2 \glspl{thrd} running on 8 queues, where the chances of getting an empty queue is 75\% per pick, meaning two random picks yield a \gls{thrd} only half the time. This scenario leads to performance problems since picks that do not yield a \gls{thrd} are not useful and do not necessarily help make more informed guesses.
         \vspace*{10pt}
+        {\resizebox{0.95\textwidth}{!}{\input{emptytls.pstex_t}}}
         \vspace*{-5pt}
         \caption[Underloaded queue with per processor bitmask]{Underloaded queue with per processor bitmask indicating array cells with items.}
         \label{fig:emptytls}
 \end{figure}
+% \begin{figure}
+%       \centering
+%       \input{empty.pstex_t}
+%       \caption[``More empty'' Relaxed FIFO list]{``More empty'' Relaxed FIFO list \smallskip\newline Emptier state of the queue: the array contains many empty cells, that is strictly FIFO lists containing no elements.}
+%       \label{fig:empty}
+% \end{figure}
+\paragraph{Sparse Information} Figure~\ref{fig:emptytree} shows an approach using a hierarchical tree data-structure to reduce contention and has been shown to work in similar cases~\cite{ellen2007snzi}. However, this approach may lead to poorer performance due to the inherent pointer chasing cost while still allowing significant contention on the nodes of the tree if the tree is shallow.
+% There are several solutions to this problem, but they ultimately all have to encode if a cell has an empty list. My results show the density and locality of this encoding is generally the dominating factor in these scheme. Classic solutions to this problem use one of three techniques to encode the information:
 \paragraph{Local Information} Figure~\ref{fig:emptytls} shows an approach using dense information, similar to the bitmap, but each \gls{hthrd} keeps its own independent copy. While this approach can offer good scalability \emph{and} low latency, the liveliness and discovery of the information can become a problem. This case is made worst in systems with few processors where even blind random picks can find \glspl{thrd} in a few tries.
+% \paragraph{Dense Information} Figure~\ref{fig:emptybit} shows a dense bitmask to identify the cell queues currently in use. This approach means processors can often find \glspl{thrd} in constant time, regardless of how many underlying queues are empty. Furthermore, modern x86 CPUs have extended bit manipulation instructions (BMI2) that allow searching the bitmask with very little overhead compared to the randomized selection approach for a filled ready queue, offering good performance even in cases with many empty inner queues. However, this technique has its limits: with a single word\footnote{Word refers here to however many bits can be written atomically.} bitmask, the total amount of ready-queue sharding is limited to the number of bits in the word. With a multi-word bitmask, this maximum limit can be increased arbitrarily, but the look-up time increases. Finally, a dense bitmap, either single or multi-word, causes additional contention problems that reduces performance because of cache misses after updates. This central update bottleneck also means the information in the bitmask is more often stale before a processor can use it to find an item, \ie mask read says there are available \glspl{thrd} but none on queue when the subsequent atomic check is done.
+I built a prototype of these approaches and none of these techniques offer satisfying performance when few threads are present. All of these approach hit the same 2 problems. First, randomly picking sub-queues is very fast. That speed means any improvement to the hit rate can easily be countered by a slow-down in look-up speed, whether or not there are empty lists. Second, the array is already sharded to avoid contention bottlenecks, so any denser data structure tends to become a bottleneck. In all cases, these factors meant the best cases scenario, \ie many threads, would get worst throughput, and the worst-case scenario, few threads, would get a better hit rate, but an equivalent poor throughput. As a result I tried an entirely different approach.
+% \begin{figure}
+%       \centering
+%       \vspace*{-5pt}
+%       {\resizebox{0.75\textwidth}{!}{\input{emptybit.pstex_t}}}
+%       \vspace*{-5pt}
+%       \caption[Underloaded queue with bitmask]{Underloaded queue with bitmask indicating array cells with items.}
+%       \label{fig:emptybit}
+\subsection{Dynamic Entropy}\cit{https://xkcd.com/2318/}
+In the worst-case scenario there are only few \glspl{thrd} ready to run, or more precisely given $P$ \glspl{proc}\footnote{For simplicity, this assumes there is a one-to-one match between \glspl{proc} and \glspl{hthrd}.}, $T$ \glspl{thrd} and $\epsilon$ a very small number, than the worst case scenario can be represented by $T = P + \epsilon$, with $\epsilon \ll P$. It is important to note in this case that fairness is effectively irrelevant. Indeed, this case is close to \emph{actually matching} the model of the ``Ideal multi-tasking CPU'' on page \pageref{q:LinuxCFS}. In this context, it is possible to use a purely internal-locality based approach and still meet the fairness requirements. This approach simply has each \gls{proc} running a single \gls{thrd} repeatedly. Or from the shared ready-queue viewpoint, each \gls{proc} pushes to a given sub-queue and then pops from the \emph{same} subqueue. The challenge is for the the scheduler to achieve good performance in both the $T = P + \epsilon$ case and the $T \gg P$ case, without affecting the fairness guarantees in the later.
+%       \vspace*{10pt}
+%       {\resizebox{0.75\textwidth}{!}{\input{emptytree.pstex_t}}}
+%       \vspace*{-5pt}
+%       \caption[Underloaded queue with binary search-tree]{Underloaded queue with binary search-tree indicating array cells with items.}
+%       \label{fig:emptytree}
+To handle this case, I use a \glsxtrshort{prng}\todo{Fix missing long form} in a novel way. There exist \glsxtrshort{prng}s that are fast, compact and can be run forward \emph{and} backwards.  Linear congruential generators~\cite{wiki:lcg} are an example of \glsxtrshort{prng}s of such \glsxtrshort{prng}s. The novel approach is to use the ability to run backwards to ``replay'' the \glsxtrshort{prng}. The scheduler uses an exclusive \glsxtrshort{prng} instance per \gls{proc}, the random-number seed effectively starts an encoding that produces a list of all accessed subqueues, from latest to oldest. Replaying the \glsxtrshort{prng} to identify cells accessed recently and which probably have data still cached.
+%       \vspace*{10pt}
+%       {\resizebox{0.95\textwidth}{!}{\input{emptytls.pstex_t}}}
+%       \vspace*{-5pt}
+%       \caption[Underloaded queue with per processor bitmask]{Underloaded queue with per processor bitmask indicating array cells with items.}
+%       \label{fig:emptytls}
+% \end{figure}
+The algorithm works as follows:
+\begin{itemize}
+        \item Each \gls{proc} has two \glsxtrshort{prng} instances, $F$ and $B$.
+        \item Push and Pop operations occur as discussed in Section~\ref{sec:sharding} with the following exceptions:
+        \begin{itemize}
+                \item Push operations use $F$ going forward on each try and on success $F$ is copied into $B$.
+                \item Pop operations use $B$ going backwards on each try.
+        \end{itemize}
+\end{itemize}
+% \paragraph{Sparse Information} Figure~\ref{fig:emptytree} shows an approach using a hierarchical tree data-structure to reduce contention and has been shown to work in similar cases~\cite{ellen2007snzi}. However, this approach may lead to poorer performance due to the inherent pointer chasing cost while still allowing significant contention on the nodes of the tree if the tree is shallow.
 The main benefit of this technique is that it basically respects the desired properties of Figure~\ref{fig:fair}. When looking for work, a \gls{proc} first looks at the last cell they pushed to, if any, and then move backwards through its accessed cells. As the \gls{proc} continues looking for work, $F$ moves backwards and $B$ stays in place. As a result, the relation between the two becomes weaker, which means that the probablisitic fairness of the algorithm reverts to normal. Chapter~\ref{proofs} discusses more formally the fairness guarantees of this algorithm.
+% \paragraph{Local Information} Figure~\ref{fig:emptytls} shows an approach using dense information, similar to the bitmap, but each \gls{hthrd} keeps its own independent copy. While this approach can offer good scalability \emph{and} low latency, the liveliness and discovery of the information can become a problem. This case is made worst in systems with few processors where even blind random picks can find \glspl{thrd} in a few tries.
+\section{Details}
+% I built a prototype of these approaches and none of these techniques offer satisfying performance when few threads are present. All of these approach hit the same 2 problems. First, randomly picking sub-queues is very fast. That speed means any improvement to the hit rate can easily be countered by a slow-down in look-up speed, whether or not there are empty lists. Second, the array is already sharded to avoid contention bottlenecks, so any denser data structure tends to become a bottleneck. In all cases, these factors meant the best cases scenario, \ie many threads, would get worst throughput, and the worst-case scenario, few threads, would get a better hit rate, but an equivalent poor throughput. As a result I tried an entirely different approach.
+% \subsection{Dynamic Entropy}\cit{https://xkcd.com/2318/}
+% In the worst-case scenario there are only few \glspl{thrd} ready to run, or more precisely given $P$ \glspl{proc}\footnote{For simplicity, this assumes there is a one-to-one match between \glspl{proc} and \glspl{hthrd}.}, $T$ \glspl{thrd} and $\epsilon$ a very small number, than the worst case scenario can be represented by $T = P + \epsilon$, with $\epsilon \ll P$. It is important to note in this case that fairness is effectively irrelevant. Indeed, this case is close to \emph{actually matching} the model of the ``Ideal multi-tasking CPU'' on page \pageref{q:LinuxCFS}. In this context, it is possible to use a purely internal-locality based approach and still meet the fairness requirements. This approach simply has each \gls{proc} running a single \gls{thrd} repeatedly. Or from the shared ready-queue viewpoint, each \gls{proc} pushes to a given sub-queue and then pops from the \emph{same} subqueue. The challenge is for the the scheduler to achieve good performance in both the $T = P + \epsilon$ case and the $T \gg P$ case, without affecting the fairness guarantees in the later.
+% To handle this case, I use a \glsxtrshort{prng}\todo{Fix missing long form} in a novel way. There exist \glsxtrshort{prng}s that are fast, compact and can be run forward \emph{and} backwards.  Linear congruential generators~\cite{wiki:lcg} are an example of \glsxtrshort{prng}s of such \glsxtrshort{prng}s. The novel approach is to use the ability to run backwards to ``replay'' the \glsxtrshort{prng}. The scheduler uses an exclusive \glsxtrshort{prng} instance per \gls{proc}, the random-number seed effectively starts an encoding that produces a list of all accessed subqueues, from latest to oldest. Replaying the \glsxtrshort{prng} to identify cells accessed recently and which probably have data still cached.
+% The algorithm works as follows:
+% \begin{itemize}
+%       \item Each \gls{proc} has two \glsxtrshort{prng} instances, $F$ and $B$.
+%       \item Push and Pop operations occur as discussed in Section~\ref{sec:sharding} with the following exceptions:
+%       \begin{itemize}
+%               \item Push operations use $F$ going forward on each try and on success $F$ is copied into $B$.
+%               \item Pop operations use $B$ going backwards on each try.
+%       \end{itemize}
+% \end{itemize}
+% The main benefit of this technique is that it basically respects the desired properties of Figure~\ref{fig:fair}. When looking for work, a \gls{proc} first looks at the last cell they pushed to, if any, and then move backwards through its accessed cells. As the \gls{proc} continues looking for work, $F$ moves backwards and $B$ stays in place. As a result, the relation between the two becomes weaker, which means that the probablisitic fairness of the algorithm reverts to normal. Chapter~\ref{proofs} discusses more formally the fairness guarantees of this algorithm.
+% \section{Details}

doc/theses/thierry_delisle_PhD/thesis/text/eval_macro.tex

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4	4
5	5	In Memory Plain Text
6
7		~~Networked Plain Text~~
8	6
9	7	Networked ZIPF

doc/theses/thierry_delisle_PhD/thesis/text/eval_micro.tex

-                      r97c215f
+                      rf5a51db
 The first step of evaluation is always to test-out small controlled cases, to ensure that the basics are working properly.
 This sections presents four different experimental setup, evaluating some of the basic features of \CFA's scheduler.
+This sections presents five different experimental setup, evaluating some of the basic features of \CFA's scheduler.
 \section{Cycling latency}
 The most basic evaluation of any ready queue is to evaluate the latency needed to push and pop one element from the ready-queue.
 While these two operation also describe a \texttt{yield} operation, many systems use this as the most basic benchmark.
 However, yielding can be treated as a special case, since it also carries the information that the length of the ready queue will not change.
+Since these two operation also describe a \texttt{yield} operation, many systems use this as the most basic benchmark.
+However, yielding can be treated as a special case, since it also carries the information that the number of the ready \glspl{at} will not change.
 Not all systems use this information, but those which do may appear to have better performance than they would for disconnected push/pop pairs.
 For this reason, I chose a different first benchmark, which I call the Cycle Benchmark.
 This benchmark arranges many threads into multiple rings of threads.
+This benchmark arranges many \glspl{at} into multiple rings of \glspl{at}.
 Each ring is effectively a circular singly-linked list.
 At runtime, each thread unparks the next thread before parking itself.
+At runtime, each \gls{at} unparks the next \gls{at} before parking itself.
 This corresponds to the desired pair of ready queue operations.
 Unparking the next thread requires pushing that thread onto the ready queue and the ensuing park will cause the runtime to pop a thread from the ready-queue.
+Unparking the next \gls{at} requires pushing that \gls{at} onto the ready queue and the ensuing park will cause the runtime to pop a \gls{at} from the ready-queue.
 Figure~\ref{fig:cycle} shows a visual representation of this arrangement.
+The goal of this ring is that the underlying runtime cannot rely on the guarantee that the number of ready threads will stay constant over the duration of the experiment.
+In fact, the total number of threads waiting on the ready is expected to vary a little because of the race between the next thread unparking and the current thread parking.
+The size of the cycle is also decided based on this race: cycles that are too small may see the
+chain of unparks go full circle before the first thread can park.
+The goal of this ring is that the underlying runtime cannot rely on the guarantee that the number of ready \glspl{at} will stay constant over the duration of the experiment.
+In fact, the total number of \glspl{at} waiting on the ready queue is expected to vary because of the race between the next \gls{at} unparking and the current \gls{at} parking.
+The size of the cycle is also decided based on this race: cycles that are too small may see the chain of unparks go full circle before the first \gls{at} can park.
 While this would not be a correctness problem, every runtime system must handle that race, it could lead to pushes and pops being optimized away.
+Since silently omitting ready-queue operations would throw off the measuring of these operations.
+Therefore the ring of threads must be big enough so the threads have the time to fully park before they are unparked.
+Since silently omitting ready-queue operations would throw off the measuring of these operations, the ring of \glspl{at} must be big enough so the \glspl{at} have the time to fully park before they are unparked.
 Note that this problem is only present on SMP machines and is significantly mitigated by the fact that there are multiple rings in the system.
 …
         \centering
         \input{cycle.pstex_t}
         \caption[Cycle benchmark]{Cycle benchmark\smallskip\newline Each thread unparks the next thread in the cycle before parking itself.}
+        \caption[Cycle benchmark]{Cycle benchmark\smallskip\newline Each \gls{at} unparks the next \gls{at} in the cycle before parking itself.}
         \label{fig:cycle}
 \end{figure}
 \todo{check term ``idle sleep handling''}
 To avoid this benchmark from being dominated by the idle sleep handling, the number of rings is kept at least as high as the number of processors available.
+To avoid this benchmark from being dominated by the idle sleep handling, the number of rings is kept at least as high as the number of \glspl{proc} available.
 Beyond this point, adding more rings serves to mitigate even more the idle sleep handling.
 This is to avoid the case where one of the worker threads runs out of work because of the variation on the number of ready threads mentionned above.
+This is to avoid the case where one of the worker \glspl{at} runs out of work because of the variation on the number of ready \glspl{at} mentionned above.
 The actual benchmark is more complicated to handle termination, but that simply requires using a binary semphore or a channel instead of raw \texttt{park}/\texttt{unpark} and carefully picking the order of the \texttt{P} and \texttt{V} with respect to the loop condition.
+\todo{mention where to get the code.}
+\todo{code, setup, results}
+\begin{lstlisting}
+        Thread.main() {
+                count := 0
+                for {
+                        wait()
+                        this.next.wake()
+                        count ++
+                        if must_stop() { break }
+                }
+                global.count += count
+        }
+\end{lstlisting}
 \section{Yield}
 For completion, I also include the yield benchmark.
+This benchmark is much simpler than the cycle tests, it simply creates many threads that call \texttt{yield}.
+This benchmark is much simpler than the cycle tests, it simply creates many \glspl{at} that call \texttt{yield}.
+As mentionned in the previous section, this benchmark may be less representative of usages that only make limited use of \texttt{yield}, due to potential shortcuts in the routine.
+Its only interesting variable is the number of \glspl{at} per \glspl{proc}, where ratios close to 1 means the ready queue(s) could be empty.
+This sometimes puts more strain on the idle sleep handling, compared to scenarios where there is clearly plenty of work to be done.
+\todo{code, setup, results}
+\begin{lstlisting}
+        Thread.main() {
+                count := 0
+                while !stop {
+                        yield()
+                        count ++
+                }
+                global.count += count
+        }
+\end{lstlisting}
+\section{Churn}
+The Cycle and Yield benchmark represents an ``easy'' scenario for a scheduler, \eg, an embarrassingly parallel application.
+In these benchmarks, \glspl{at} can be easily partitioned over the different \glspl{proc} up-front and none of the \glspl{at} communicate with each other.
+The Churn benchmark represents more chaotic usages, where there is no relation between the last \gls{proc} on which a \gls{at} ran and the \gls{proc} that unblocked it.
+When a \gls{at} is unblocked from a different \gls{proc} than the one on which it last ran, the unblocking \gls{proc} must either ``steal'' the \gls{at} or place it on a remote queue.
+This results can result in either contention on the remote queue or \glspl{rmr} on \gls{at} data structure.
+In either case, this benchmark aims to highlight how each scheduler handles these cases, since both cases can lead to performance degradation if they are not handled correctly.
+To achieve this the benchmark uses a fixed size array of \newterm{chair}s, where a chair is a data structure that holds a single blocked \gls{at}.
+When a \gls{at} attempts to block on the chair, it must first unblocked the \gls{at} currently blocked on said chair, if any.
+This creates a flow where \glspl{at} push each other out of the chairs before being pushed out themselves.
+For this benchmark to work however, the number of \glspl{at} must be equal or greater to the number of chairs plus the number of \glspl{proc}.
+\todo{code, setup, results}
+\begin{lstlisting}
+        Thread.main() {
+                count := 0
+                for {
+                        r := random() % len(spots)
+                        next := xchg(spots[r], this)
+                        if next { next.wake() }
+                        wait()
+                        count ++
+                        if must_stop() { break }
+                }
+                global.count += count
+        }
+\end{lstlisting}
 \section{Locality}
+\todo{code, setup, results}
 \section{Transfer}
+The last benchmark is more exactly characterize as an experiment than a benchmark.
+It tests the behavior of the schedulers for a particularly misbehaved workload.
+In this workload, one of the \gls{at} is selected at random to be the leader.
+The leader then spins in a tight loop until it has observed that all other \glspl{at} have acknowledged its leadership.
+The leader \gls{at} then picks a new \gls{at} to be the ``spinner'' and the cycle repeats.
+The benchmark comes in two flavours for the behavior of the non-leader \glspl{at}:
+once they acknowledged the leader, they either block on a semaphore or yield repeatadly.
+This experiment is designed to evaluate the short term load balancing of the scheduler.
+Indeed, schedulers where the runnable \glspl{at} are partitioned on the \glspl{proc} may need to balance the \glspl{at} for this experient to terminate.
+This is because the spinning \gls{at} is effectively preventing the \gls{proc} from runnning any other \glspl{thrd}.
+In the semaphore flavour, the number of runnable \glspl{at} will eventually dwindle down to only the leader.
+This is a simpler case to handle for schedulers since \glspl{proc} eventually run out of work.
+In the yielding flavour, the number of runnable \glspl{at} stays constant.
+This is a harder case to handle because corrective measures must be taken even if work is still available.
+Note that languages that have mandatory preemption do circumvent this problem by forcing the spinner to yield.
+\todo{code, setup, results}
+\begin{lstlisting}
+        Thread.lead() {
+                this.idx_seen = ++lead_idx
+                if lead_idx > stop_idx {
+                        done := true
+                        return
+                }
+                // Wait for everyone to acknowledge my leadership
+                start: = timeNow()
+                for t in threads {
+                        while t.idx_seen != lead_idx {
+                                asm pause
+                                if (timeNow() - start) > 5 seconds { error() }
+                        }
+                }
+                // pick next leader
+                leader := threads[ prng() % len(threads) ]
+                // wake every one
+                if !exhaust {
+                        for t in threads {
+                                if t != me { t.wake() }
+                        }
+                }
+        }
+        Thread.wait() {
+                this.idx_seen := lead_idx
+                if exhaust { wait() }
+                else { yield() }
+        }
+        Thread.main() {
+                while !done  {
+                        if leader == me { this.lead() }
+                        else { this.wait() }
+                }
+        }
+\end{lstlisting}

doc/theses/thierry_delisle_PhD/thesis/text/existing.tex

r97c215f	rf5a51db
33	33
34	34
35		\section{Work Stealing}
	35	\section{Work Stealing}\label{existing:workstealing}
36	36	One of the most popular scheduling algorithm in practice (see~\ref{existing:prod}) is work-stealing. This idea, introduce by \cite{DBLP:conf/fpca/BurtonS81}, effectively has each worker work on its local tasks first, but allows the possibility for other workers to steal local tasks if they run out of tasks. \cite{DBLP:conf/focs/Blumofe94} introduced the more familiar incarnation of this, where each workers has queue of tasks to accomplish and workers without tasks steal tasks from random workers. (The Burton and Sleep algorithm had trees of tasks and stole only among neighbours). Blumofe and Leiserson also prove worst case space and time requirements for well-structured computations.
37	37

libcfa/src/concurrency/io.cfa

-                      r97c215f
+                      rf5a51db
                 ctx->proc->io.pending = true;
                 ctx->proc->io.dirty   = true;
+                if(sq.to_submit > 30 || !lazy) {
+                if(sq.to_submit > 30) {
+                        __tls_stats()->io.flush.full++;
+                        __cfa_io_flush( ctx->proc, 0 );
+                }
+                if(!lazy) {
+                        __tls_stats()->io.flush.eager++;
                         __cfa_io_flush( ctx->proc, 0 );
+                }

libcfa/src/concurrency/kernel.cfa

-                      r97c215f
+                      rf5a51db
 #if !defined(__CFA_NO_STATISTICS__)
         #define __STATS( ...) __VA_ARGS__
+        #define __STATS_DEF( ...) __VA_ARGS__
 #else
         #define __STATS( ...)
+        #define __STATS_DEF( ...)
 #endif
 …
 static thread$ * __next_thread(cluster * this);
 static thread$ * __next_thread_slow(cluster * this);
+static thread$ * __next_thread_search(cluster * this);
 static inline bool __must_unpark( thread$ * thrd ) __attribute((nonnull(1)));
 static void __run_thread(processor * this, thread$ * dst);
 …
                 MAIN_LOOP:
                 for() {
-                        #define OLD_MAIN 1
-                        #if OLD_MAIN
                         // Check if there is pending io
                         __maybe_io_drain( this );
 …
                         if( !readyThread ) {
+                                __IO_STATS__(true, io.flush.idle++; )
                                 __cfa_io_flush( this, 0 );
+                                readyThread = __next_thread( this->cltr );
+                        }
+                        if( !readyThread ) for(5) {
+                                __IO_STATS__(true, io.flush.idle++; )
                                 readyThread = __next_thread_slow( this->cltr );
+                                if( readyThread ) break;
+                                __cfa_io_flush( this, 0 );
+                        }
 …
                                 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
-                                #if !defined(__CFA_NO_STATISTICS__)
-                                        __tls_stats()->ready.sleep.halts++;
-                                #endif
                                 // Push self to idle stack
                                 if(!mark_idle(this->cltr->procs, * this)) continue MAIN_LOOP;
                                 // Confirm the ready-queue is empty
                                 readyThread = __next_thread_slow( this->cltr );
+                                readyThread = __next_thread_search( this->cltr );
                                 if( readyThread ) {
                                         // A thread was found, cancel the halt
                                         mark_awake(this->cltr->procs, * this);
+                                        #if !defined(__CFA_NO_STATISTICS__)
+                                                __tls_stats()->ready.sleep.cancels++;
+                                        #endif
+                                        __STATS__(true, ready.sleep.cancels++; )
                                         // continue the mai loop
 …
                         if(this->io.pending && !this->io.dirty) {
+                                __IO_STATS__(true, io.flush.dirty++; )
                                 __cfa_io_flush( this, 0 );
+                        }
-                        #else
-                                #warning new kernel loop
-                        SEARCH: {
-                                /* paranoid */ verify( ! __preemption_enabled() );
-                                // First, lock the scheduler since we are searching for a thread
-                                ready_schedule_lock();
-                                // Try to get the next thread
-                                readyThread = pop_fast( this->cltr );
-                                if(readyThread) { ready_schedule_unlock(); break SEARCH; }
-                                // If we can't find a thread, might as well flush any outstanding I/O
-                                if(this->io.pending) { __cfa_io_flush( this, 0 ); }
-                                // Spin a little on I/O, just in case
-                                for(5) {
-                                        __maybe_io_drain( this );
-                                        readyThread = pop_fast( this->cltr );
-                                        if(readyThread) { ready_schedule_unlock(); break SEARCH; }
+                                }
-                                // no luck, try stealing a few times
-                                for(5) {
-                                        if( __maybe_io_drain( this ) ) {
-                                                readyThread = pop_fast( this->cltr );
-                                        } else {
-                                                readyThread = pop_slow( this->cltr );
+                                        }
-                                        if(readyThread) { ready_schedule_unlock(); break SEARCH; }
+                                }
-                                // still no luck, search for a thread
-                                readyThread = pop_search( this->cltr );
-                                if(readyThread) { ready_schedule_unlock(); break SEARCH; }
-                                // Don't block if we are done
-                                if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) {
-                                        ready_schedule_unlock();
-                                        break MAIN_LOOP;
+                                }
-                                __STATS( __tls_stats()->ready.sleep.halts++; )
-                                // Push self to idle stack
-                                ready_schedule_unlock();
-                                if(!mark_idle(this->cltr->procs, * this)) goto SEARCH;
-                                ready_schedule_lock();
-                                // Confirm the ready-queue is empty
-                                __maybe_io_drain( this );
-                                readyThread = pop_search( this->cltr );
-                                ready_schedule_unlock();
-                                if( readyThread ) {
-                                        // A thread was found, cancel the halt
-                                        mark_awake(this->cltr->procs, * this);
-                                        __STATS( __tls_stats()->ready.sleep.cancels++; )
-                                        // continue the main loop
-                                        break SEARCH;
+                                }
-                                __STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl()); )
-                                __cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle_fd);
+                                {
-                                        eventfd_t val;
-                                        ssize_t ret = read( this->idle_fd, &val, sizeof(val) );
-                                        if(ret < 0) {
-                                                switch((int)errno) {
-                                                case EAGAIN:
-                                                #if EAGAIN != EWOULDBLOCK
-                                                        case EWOULDBLOCK:
-                                                #endif
-                                                case EINTR:
-                                                        // No need to do anything special here, just assume it's a legitimate wake-up
-                                                        break;
-                                                default:
-                                                        abort( "KERNEL : internal error, read failure on idle eventfd, error(%d) %s.", (int)errno, strerror( (int)errno ) );
+                                                }
+                                        }
+                                }
-                                        __STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl()); )
-                                // We were woken up, remove self from idle
-                                mark_awake(this->cltr->procs, * this);
-                                // DON'T just proceed, start looking again
-                                continue MAIN_LOOP;
+                        }
-                RUN_THREAD:
-                        /* paranoid */ verify( ! __preemption_enabled() );
-                        /* paranoid */ verify( readyThread );
-                        // Reset io dirty bit
-                        this->io.dirty = false;
-                        // We found a thread run it
-                        __run_thread(this, readyThread);
-                        // Are we done?
-                        if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
-                        if(this->io.pending && !this->io.dirty) {
-                                __cfa_io_flush( this, 0 );
+                        }
-                        ready_schedule_lock();
-                        __maybe_io_drain( this );
-                        ready_schedule_unlock();
-                        #endif
+                }
 …
                                 break RUNNING;
                         case TICKET_UNBLOCK:
+                                #if !defined(__CFA_NO_STATISTICS__)
+                                        __tls_stats()->ready.threads.threads++;
+                                #endif
+                                __STATS__(true, ready.threads.threads++; )
                                 // This is case 2, the racy case, someone tried to run this thread before it finished blocking
                                 // In this case, just run it again.
 …
         __cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
+        #if !defined(__CFA_NO_STATISTICS__)
+                __tls_stats()->ready.threads.threads--;
+        #endif
+        __STATS__(true, ready.threads.threads--; )
         /* paranoid */ verify( ! __preemption_enabled() );
 …
         thread$ * thrd_src = kernelTLS().this_thread;
         __STATS( thrd_src->last_proc = kernelTLS().this_processor; )
+        __STATS_DEF( thrd_src->last_proc = kernelTLS().this_processor; )
         // Run the thread on this processor
 …
         // Dereference the thread now because once we push it, there is not guaranteed it's still valid.
         struct cluster * cl = thrd->curr_cluster;
         __STATS(bool outside = hint == UNPARK_LOCAL && thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
+        __STATS_DEF(bool outside = hint == UNPARK_LOCAL && thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
         // push the thread to the cluster ready-queue
 …
         ready_schedule_lock();
+                thread$ * thrd;
+                for(25) {
+                        thrd = pop_slow( this );
+                        if(thrd) goto RET;
+                }
+                thrd = pop_search( this );
+                RET:
+                thread$ * thrd = pop_slow( this );
+        ready_schedule_unlock();
+        /* paranoid */ verify( ! __preemption_enabled() );
+        return thrd;
+}
+// KERNEL ONLY
+static inline thread$ * __next_thread_search(cluster * this) with( *this ) {
+        /* paranoid */ verify( ! __preemption_enabled() );
+        ready_schedule_lock();
+                thread$ * thrd = pop_search( this );
         ready_schedule_unlock();
 …
 // Wake a thread from the front if there are any
 static void __wake_one(cluster * this) {
+        eventfd_t val;
         /* paranoid */ verify( ! __preemption_enabled() );
         /* paranoid */ verify( ready_schedule_islocked() );
         // Check if there is a sleeping processor
+        // int fd = __atomic_load_n(&this->procs.fd, __ATOMIC_SEQ_CST);
+        int fd = 0;
+        if( __atomic_load_n(&this->procs.fd, __ATOMIC_SEQ_CST) != 0 ) {
+                fd = __atomic_exchange_n(&this->procs.fd, 0, __ATOMIC_RELAXED);
+        }
+        // If no one is sleeping, we are done
+        if( fd == 0 ) return;
+        // We found a processor, wake it up
+        eventfd_t val;
+        val = 1;
+        eventfd_write( fd, val );
+        #if !defined(__CFA_NO_STATISTICS__)
+                if( kernelTLS().this_stats ) {
+                        __tls_stats()->ready.sleep.wakes++;
+                }
+                else {
+                        __atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
+                }
+        #endif
+        struct __fd_waitctx * fdp = __atomic_load_n(&this->procs.fdw, __ATOMIC_SEQ_CST);
+        // If no one is sleeping: we are done
+        if( fdp == 0p ) return;
+        int fd = 1;
+        if( __atomic_load_n(&fdp->fd, __ATOMIC_SEQ_CST) != 1 ) {
+                fd = __atomic_exchange_n(&fdp->fd, 1, __ATOMIC_RELAXED);
+        }
+        switch(fd) {
+        case 0:
+                // If the processor isn't ready to sleep then the exchange will already wake it up
+                #if !defined(__CFA_NO_STATISTICS__)
+                        if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.early++;
+                        } else { __atomic_fetch_add(&this->stats->ready.sleep.early, 1, __ATOMIC_RELAXED); }
+                #endif
+                break;
+        case 1:
+                // If someone else already said they will wake them: we are done
+                #if !defined(__CFA_NO_STATISTICS__)
+                        if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.seen++;
+                        } else { __atomic_fetch_add(&this->stats->ready.sleep.seen, 1, __ATOMIC_RELAXED); }
+                #endif
+                break;
+        default:
+                // If the processor was ready to sleep, we need to wake it up with an actual write
+                val = 1;
+                eventfd_write( fd, val );
+                #if !defined(__CFA_NO_STATISTICS__)
+                        if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.wakes++;
+                        } else { __atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED); }
+                #endif
+                break;
+        }
         /* paranoid */ verify( ready_schedule_islocked() );
 …
         __cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
+        this->idle_wctx.fd = 1;
         eventfd_t val;
 …
 static void idle_sleep(processor * this, io_future_t & future, iovec & iov) {
+        // Tell everyone we are ready to go do sleep
+        for() {
+                int expected = this->idle_wctx.fd;
+                // Someone already told us to wake-up! No time for a nap.
+                if(expected == 1) { return; }
+                // Try to mark that we are going to sleep
+                if(__atomic_compare_exchange_n(&this->idle_wctx.fd, &expected, this->idle_fd, false,  __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) {
+                        // Every one agreed, taking a nap
+                        break;
+                }
+        }
         #if !defined(CFA_WITH_IO_URING_IDLE)
                 #if !defined(__CFA_NO_STATISTICS__)
 …
 static bool mark_idle(__cluster_proc_list & this, processor & proc) {
+        __STATS__(true, ready.sleep.halts++; )
+        proc.idle_wctx.fd = 0;
         /* paranoid */ verify( ! __preemption_enabled() );
         if(!try_lock( this )) return false;
 …
                 insert_first(this.idles, proc);
                 __atomic_store_n(&this.fd, proc.idle_fd, __ATOMIC_SEQ_CST);
+                __atomic_store_n(&this.fdw, &proc.idle_wctx, __ATOMIC_SEQ_CST);
         unlock( this );
         /* paranoid */ verify( ! __preemption_enabled() );
 …
+                {
                         int fd = 0;
                         if(!this.idles`isEmpty) fd = this.idles`first.idle_fd;
                         __atomic_store_n(&this.fd, fd, __ATOMIC_SEQ_CST);
+                        struct __fd_waitctx * wctx = 0;
+                        if(!this.idles`isEmpty) wctx = &this.idles`first.idle_wctx;
+                        __atomic_store_n(&this.fdw, wctx, __ATOMIC_SEQ_CST);
+                }
 …
                 unsigned tail = *ctx->cq.tail;
                 if(head == tail) return false;
+                #if OLD_MAIN
+                        ready_schedule_lock();
+                        ret = __cfa_io_drain( proc );
+                        ready_schedule_unlock();
+                #else
+                        ret = __cfa_io_drain( proc );
+                #endif
+                ready_schedule_lock();
+                ret = __cfa_io_drain( proc );
+                ready_schedule_unlock();
         #endif
         return ret;

libcfa/src/concurrency/kernel.hfa

-                      r97c215f
+                      rf5a51db
 coroutine processorCtx_t {
         struct processor * proc;
+};
+struct __fd_waitctx {
+        volatile int fd;
 };
 …
         int idle_fd;
+        // Idle waitctx
+        struct __fd_waitctx idle_wctx;
         // Termination synchronisation (user semaphore)
         oneshot terminated;
 …
         // FD to use to wake a processor
         volatile int fd;
+        struct __fd_waitctx * volatile fdw;
         // Total number of processors

libcfa/src/concurrency/kernel/fwd.hfa

-                      r97c215f
+                      rf5a51db
                                 if( !(in_kernel) ) enable_interrupts(); \
+                        }
+                        #if defined(CFA_HAVE_LINUX_IO_URING_H)
+                                #define __IO_STATS__(in_kernel, ...) { \
+                                        if( !(in_kernel) ) disable_interrupts(); \
+                                        with( *__tls_stats() ) { \
+                                                __VA_ARGS__ \
+                                        } \
+                                        if( !(in_kernel) ) enable_interrupts(); \
+                                }
+                        #else
+                                #define __IO_STATS__(in_kernel, ...)
+                        #endif
                 #else
                         #define __STATS__(in_kernel, ...)
+                        #define __IO_STATS__(in_kernel, ...)
                 #endif
+        }

libcfa/src/concurrency/kernel/startup.cfa

-                      r97c215f
+                      rf5a51db
+        }
+        this.idle_wctx.fd = 0;
+        // I'm assuming these two are reserved for standard input and output
+        // so I'm using them as sentinels with idle_wctx.
+        /* paranoid */ verify( this.idle_fd != 0 );
+        /* paranoid */ verify( this.idle_fd != 1 );
         #if !defined(__CFA_NO_STATISTICS__)
                 print_stats = 0;
 …
 // Cluster
 static void ?{}(__cluster_proc_list & this) {
         this.fd    = 0;
+        this.fdw   = 0p;
         this.idle  = 0;
         this.total = 0;

libcfa/src/concurrency/mutex_stmt.hfa

-                      r97c215f
+                      rf5a51db
+    }
+    struct scoped_lock {
+        L * internal_lock;
+    };
+    static inline void ?{}( scoped_lock(L) & this, L & internal_lock ) {
+        this.internal_lock = &internal_lock;
+        lock(internal_lock);
+    }
+    static inline void ^?{}( scoped_lock(L) & this ) with(this) {
+        unlock(*internal_lock);
+    }
     static inline L * __get_ptr( L & this ) {
         return &this;

libcfa/src/concurrency/preemption.cfa

-                      r97c215f
+                      rf5a51db
         bool enabled = __cfaabi_tls.preemption_state.enabled;
+        // Check if there is a pending preemption
+        processor   * proc = __cfaabi_tls.this_processor;
+        bool pending = proc ? proc->pending_preemption : false;
+        if( enabled && pending ) proc->pending_preemption = false;
         // create a assembler label after
         // marked as clobber all to avoid movement
         __cfaasm_label(check, after);
+        // If we can preempt and there is a pending one
+        // this is a good time to yield
+        if( enabled && pending ) {
+                force_yield( __POLL_PREEMPTION );
+        }
         return enabled;
+}
 …
         // marked as clobber all to avoid movement
         __cfaasm_label(get, after);
+        // This is used everywhere, to avoid cost, we DO NOT poll pending preemption
         return val;
+}
 …
         if(!ready) { abort("Preemption should be ready"); }
+        __cfaasm_label(debug, before);
+                sigset_t oldset;
+                int ret;
+                ret = pthread_sigmask(0, ( const sigset_t * ) 0p, &oldset);  // workaround trac#208: cast should be unnecessary
+                if(ret != 0) { abort("ERROR sigprocmask returned %d", ret); }
+                ret = sigismember(&oldset, SIGUSR1);
+                if(ret <  0) { abort("ERROR sigismember returned %d", ret); }
+                if(ret == 1) { abort("ERROR SIGUSR1 is disabled"); }
+                ret = sigismember(&oldset, SIGALRM);
+                if(ret <  0) { abort("ERROR sigismember returned %d", ret); }
+                if(ret == 0) { abort("ERROR SIGALRM is enabled"); }
+                ret = sigismember(&oldset, SIGTERM);
+                if(ret <  0) { abort("ERROR sigismember returned %d", ret); }
+                if(ret == 1) { abort("ERROR SIGTERM is disabled"); }
+        __cfaasm_label(debug, after);
+        sigset_t oldset;
+        int ret;
+        ret = pthread_sigmask(0, ( const sigset_t * ) 0p, &oldset);  // workaround trac#208: cast should be unnecessary
+        if(ret != 0) { abort("ERROR sigprocmask returned %d", ret); }
+        ret = sigismember(&oldset, SIGUSR1);
+        if(ret <  0) { abort("ERROR sigismember returned %d", ret); }
+        if(ret == 1) { abort("ERROR SIGUSR1 is disabled"); }
+        ret = sigismember(&oldset, SIGALRM);
+        if(ret <  0) { abort("ERROR sigismember returned %d", ret); }
+        if(ret == 0) { abort("ERROR SIGALRM is enabled"); }
+        ret = sigismember(&oldset, SIGTERM);
+        if(ret <  0) { abort("ERROR sigismember returned %d", ret); }
+        if(ret == 1) { abort("ERROR SIGTERM is disabled"); }
+}
 …
         __cfaasm_label( check  );
         __cfaasm_label( dsable );
         __cfaasm_label( debug  );
+        // __cfaasm_label( debug  );
         // Check if preemption is safe
 …
         if( __cfaasm_in( ip, check  ) ) { ready = false; goto EXIT; };
         if( __cfaasm_in( ip, dsable ) ) { ready = false; goto EXIT; };
         if( __cfaasm_in( ip, debug  ) ) { ready = false; goto EXIT; };
+        // if( __cfaasm_in( ip, debug  ) ) { ready = false; goto EXIT; };
         if( !__cfaabi_tls.preemption_state.enabled) { ready = false; goto EXIT; };
         if( __cfaabi_tls.preemption_state.in_progress ) { ready = false; goto EXIT; };
 …
         // Check if it is safe to preempt here
+        if( !preemption_ready( ip ) ) { return; }
+        if( !preemption_ready( ip ) ) {
+                #if !defined(__CFA_NO_STATISTICS__)
+                        __cfaabi_tls.this_stats->ready.threads.preempt.rllfwd++;
+                #endif
+                return;
+        }
         __cfaabi_dbg_print_buffer_decl( " KERNEL: preempting core %p (%p @ %p).\n", __cfaabi_tls.this_processor, __cfaabi_tls.this_thread, (void *)(cxt->uc_mcontext.CFA_REG_IP) );
 …
         // Preemption can occur here
+        #if !defined(__CFA_NO_STATISTICS__)
+                __cfaabi_tls.this_stats->ready.threads.preempt.yield++;
+        #endif
         force_yield( __ALARM_PREEMPTION ); // Do the actual __cfactx_switch

libcfa/src/concurrency/ready_queue.cfa

-                      r97c215f
+                      rf5a51db
 uint_fast32_t ready_mutate_lock( void ) with(*__scheduler_lock) {
         /* paranoid */ verify( ! __preemption_enabled() );
-        /* paranoid */ verify( ! kernelTLS().sched_lock );
         // Step 1 : lock global lock
 …
         //   to simply lock their own lock and enter.
         __atomic_acquire( &write_lock );
+        // Make sure we won't deadlock ourself
+        // Checking before acquiring the writer lock isn't safe
+        // because someone else could have locked us.
+        /* paranoid */ verify( ! kernelTLS().sched_lock );
         // Step 2 : lock per-proc lock

libcfa/src/concurrency/stats.cfa

-                      r97c215f
+                      rf5a51db
                 stats->ready.threads.threads   = 0;
                 stats->ready.threads.cthreads  = 0;
+                stats->ready.threads.preempt.yield  = 0;
+                stats->ready.threads.preempt.rllfwd = 0;
                 stats->ready.sleep.halts   = 0;
                 stats->ready.sleep.cancels = 0;
+                stats->ready.sleep.early   = 0;
                 stats->ready.sleep.wakes   = 0;
+                stats->ready.sleep.seen    = 0;
                 stats->ready.sleep.exits   = 0;
 …
                         stats->io.submit.slow       = 0;
                         stats->io.flush.external    = 0;
+                        stats->io.flush.dirty       = 0;
+                        stats->io.flush.full        = 0;
+                        stats->io.flush.idle        = 0;
+                        stats->io.flush.eager       = 0;
                         stats->io.calls.flush       = 0;
                         stats->io.calls.submitted   = 0;
 …
         void __tally_stats( struct __stats_t * cltr, struct __stats_t * proc ) {
+                tally_one( &cltr->ready.push.local.attempt, &proc->ready.push.local.attempt );
+                tally_one( &cltr->ready.push.local.success, &proc->ready.push.local.success );
+                tally_one( &cltr->ready.push.share.attempt, &proc->ready.push.share.attempt );
+                tally_one( &cltr->ready.push.share.success, &proc->ready.push.share.success );
+                tally_one( &cltr->ready.push.extrn.attempt, &proc->ready.push.extrn.attempt );
+                tally_one( &cltr->ready.push.extrn.success, &proc->ready.push.extrn.success );
+                tally_one( &cltr->ready.pop.local .attempt, &proc->ready.pop.local .attempt );
+                tally_one( &cltr->ready.pop.local .success, &proc->ready.pop.local .success );
+                tally_one( &cltr->ready.pop.help  .attempt, &proc->ready.pop.help  .attempt );
+                tally_one( &cltr->ready.pop.help  .success, &proc->ready.pop.help  .success );
+                tally_one( &cltr->ready.pop.steal .attempt, &proc->ready.pop.steal .attempt );
+                tally_one( &cltr->ready.pop.steal .success, &proc->ready.pop.steal .success );
+                tally_one( &cltr->ready.pop.search.attempt, &proc->ready.pop.search.attempt );
+                tally_one( &cltr->ready.pop.search.success, &proc->ready.pop.search.success );
+                tally_one( &cltr->ready.threads.migration , &proc->ready.threads.migration  );
+                tally_one( &cltr->ready.threads.extunpark , &proc->ready.threads.extunpark  );
+                tally_one( &cltr->ready.threads.threads   , &proc->ready.threads.threads    );
+                tally_one( &cltr->ready.threads.cthreads  , &proc->ready.threads.cthreads   );
+                tally_one( &cltr->ready.sleep.halts       , &proc->ready.sleep.halts        );
+                tally_one( &cltr->ready.sleep.cancels     , &proc->ready.sleep.cancels      );
+                tally_one( &cltr->ready.sleep.wakes       , &proc->ready.sleep.wakes        );
+                tally_one( &cltr->ready.sleep.exits       , &proc->ready.sleep.exits        );
+                tally_one( &cltr->ready.push.local.attempt    , &proc->ready.push.local.attempt     );
+                tally_one( &cltr->ready.push.local.success    , &proc->ready.push.local.success     );
+                tally_one( &cltr->ready.push.share.attempt    , &proc->ready.push.share.attempt     );
+                tally_one( &cltr->ready.push.share.success    , &proc->ready.push.share.success     );
+                tally_one( &cltr->ready.push.extrn.attempt    , &proc->ready.push.extrn.attempt     );
+                tally_one( &cltr->ready.push.extrn.success    , &proc->ready.push.extrn.success     );
+                tally_one( &cltr->ready.pop.local .attempt    , &proc->ready.pop.local .attempt     );
+                tally_one( &cltr->ready.pop.local .success    , &proc->ready.pop.local .success     );
+                tally_one( &cltr->ready.pop.help  .attempt    , &proc->ready.pop.help  .attempt     );
+                tally_one( &cltr->ready.pop.help  .success    , &proc->ready.pop.help  .success     );
+                tally_one( &cltr->ready.pop.steal .attempt    , &proc->ready.pop.steal .attempt     );
+                tally_one( &cltr->ready.pop.steal .success    , &proc->ready.pop.steal .success     );
+                tally_one( &cltr->ready.pop.search.attempt    , &proc->ready.pop.search.attempt     );
+                tally_one( &cltr->ready.pop.search.success    , &proc->ready.pop.search.success     );
+                tally_one( &cltr->ready.threads.migration     , &proc->ready.threads.migration      );
+                tally_one( &cltr->ready.threads.extunpark     , &proc->ready.threads.extunpark      );
+                tally_one( &cltr->ready.threads.threads       , &proc->ready.threads.threads        );
+                tally_one( &cltr->ready.threads.cthreads      , &proc->ready.threads.cthreads       );
+                tally_one( &cltr->ready.threads.preempt.yield , &proc->ready.threads.preempt.yield  );
+                tally_one( &cltr->ready.threads.preempt.rllfwd, &proc->ready.threads.preempt.rllfwd );
+                tally_one( &cltr->ready.sleep.halts           , &proc->ready.sleep.halts            );
+                tally_one( &cltr->ready.sleep.cancels         , &proc->ready.sleep.cancels          );
+                tally_one( &cltr->ready.sleep.early           , &proc->ready.sleep.early            );
+                tally_one( &cltr->ready.sleep.wakes           , &proc->ready.sleep.wakes            );
+                tally_one( &cltr->ready.sleep.seen            , &proc->ready.sleep.wakes            );
+                tally_one( &cltr->ready.sleep.exits           , &proc->ready.sleep.exits            );
                 #if defined(CFA_HAVE_LINUX_IO_URING_H)
 …
                         tally_one( &cltr->io.submit.slow      , &proc->io.submit.slow       );
                         tally_one( &cltr->io.flush.external   , &proc->io.flush.external    );
+                        tally_one( &cltr->io.flush.dirty      , &proc->io.flush.dirty       );
+                        tally_one( &cltr->io.flush.full       , &proc->io.flush.full        );
+                        tally_one( &cltr->io.flush.idle       , &proc->io.flush.idle        );
+                        tally_one( &cltr->io.flush.eager      , &proc->io.flush.eager       );
                         tally_one( &cltr->io.calls.flush      , &proc->io.calls.flush       );
                         tally_one( &cltr->io.calls.submitted  , &proc->io.calls.submitted   );
 …
                              | " (" | eng3(ready.pop.search.attempt) | " try)";
+                        sstr | "- Idle Slp : " | eng3(ready.sleep.halts) | "halt," | eng3(ready.sleep.cancels) | "cancel," | eng3(ready.sleep.wakes) | "wake," | eng3(ready.sleep.exits) | "exit";
+                        sstr | "- Idle Slp : " | eng3(ready.sleep.halts) | "halt," | eng3(ready.sleep.cancels) | "cancel,"
+                             | eng3(ready.sleep.wakes + ready.sleep.early) | '(' | eng3(ready.sleep.early) | ',' | eng3(ready.sleep.seen) | ')' | " wake(early, seen),"
+                             | eng3(ready.sleep.exits) | "exit";
+                        sstr | "- Preemption : " | eng3(ready.threads.preempt.yield) | "yields," | eng3(ready.threads.preempt.rllfwd) | "delayed";
                         sstr | nl;
+                }
 …
                                 if(io.alloc.fail || io.alloc.revoke || io.alloc.block)
                                         sstr | "-     failures      : " | eng3(io.alloc.fail) | "oom, " | eng3(io.alloc.revoke) | "rvk, " | eng3(io.alloc.block) | "blk";
                                 if(io.flush.external)
                                         sstr | "- flush external    : " | eng3(io.flush.external);
+                                // if(io.flush.external)
+                                //      sstr | "- flush external    : " | eng3(io.flush.external);
                                 double avgsubs = ((double)io.calls.submitted) / io.calls.flush;
                                 double avgcomp = ((double)io.calls.completed) / io.calls.drain;
                                 sstr | "- syscll : "
                                      |   " sub " | eng3(io.calls.flush) | "/" | eng3(io.calls.submitted) | "(" | ws(3, 3, avgsubs) | "/flush)"
                                      | " - cmp " | eng3(io.calls.drain) | "/" | eng3(io.calls.completed) | "(" | ws(3, 3, avgcomp) | "/drain)"
+                                     |   " sub " | eng3(io.calls.submitted) | "/" | eng3(io.calls.flush) | "(" | ws(3, 3, avgsubs) | "/flush)"
+                                     | " - cmp " | eng3(io.calls.completed) | "/" | eng3(io.calls.drain) | "(" | ws(3, 3, avgcomp) | "/drain)"
                                      | " - " | eng3(io.calls.errors.busy) | " EBUSY";
+                                sstr | " - sub: " | eng3(io.flush.full) | "full, " | eng3(io.flush.dirty) | "drty, " | eng3(io.flush.idle) | "idle, " | eng3(io.flush.eager) | "eagr, " | eng3(io.flush.external) | "ext";
                                 sstr | "- ops blk: "
                                      |   " sk rd: " | eng3(io.ops.sockread)  | "epll: " | eng3(io.ops.epllread)

libcfa/src/concurrency/stats.hfa

-                      r97c215f
+                      rf5a51db
                         volatile  int64_t threads;  // number of threads in the system, includes only local change
                         volatile  int64_t cthreads; // number of threads in the system, includes only local change
+                        struct {
+                                volatile uint64_t yield;
+                                volatile uint64_t rllfwd;
+                        } preempt;
                 } threads;
                 struct {
                         volatile uint64_t halts;
                         volatile uint64_t cancels;
+                        volatile uint64_t early;
                         volatile uint64_t wakes;
+                        volatile uint64_t seen;
                         volatile uint64_t exits;
                 } sleep;
 …
                         struct {
                                 volatile uint64_t external;
+                                volatile uint64_t dirty;
+                                volatile uint64_t full;
+                                volatile uint64_t idle;
+                                volatile uint64_t eager;
                         } flush;
                         struct {

libcfa/src/stdhdr/pthread.h

-                      r97c215f
+                      rf5a51db
 // Created On       : Wed Jun 16 13:39:06 2021
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Wed Jun 16 13:39:42 2021
 // Update Count     : 1
+// Last Modified On : Thu Feb  3 21:53:26 2022
+// Update Count     : 13
 //
+// pthread.h and setjmp.h cannot agree on the type of __sigsetjmp:
+//
+//   extern int __sigsetjmp (struct __jmp_buf_tag *__env, int __savemask) __attribute__ ((__nothrow__));
+//   extern int __sigsetjmp (struct __jmp_buf_tag __env[1], int __savemask) __attribute__ ((__nothrow__));
+//
+// With -Wall, gcc-11 warns about the disagreement unless the CPP directive
+//
+//    # 1 "/usr/include/pthread.h" 1 3 4
+//
+// appears, which appears to be witchcraft. Unfortunately, this directive is removed by the CFA preprocessor, so the
+// batchtest fails because of the spurious warning message. Hence, the warning is elided.
 extern "C" {
+#if defined(__GNUC__) && __GNUC__ == 11
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Warray-parameter"
+#endif // defined(__GNUC__) && __GNUC__ == 11
 #include_next <pthread.h>                                                               // has internal check for multiple expansion
+#if defined(__GNUC__) && __GNUC__ == 11
+        #pragma GCC diagnostic pop
+#endif // defined(__GNUC__) && __GNUC__ == 11
 } // extern "C"
 // Local Variables: //
-// tab-width: 4 //
 // mode: c++ //
-// compile-command: "make install" //
 // End: //

libcfa/src/stdhdr/setjmp.h

-                      r97c215f
+                      rf5a51db
 // Created On       : Mon Jul  4 23:25:26 2016
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Tue Jul  5 20:38:33 2016
 // Update Count     : 12
+// Last Modified On : Thu Feb  3 21:53:28 2022
+// Update Count     : 18
 //
+// pthread.h and setjmp.h cannot agree on the type of __sigsetjmp:
+//
+//   extern int __sigsetjmp (struct __jmp_buf_tag *__env, int __savemask) __attribute__ ((__nothrow__));
+//   extern int __sigsetjmp (struct __jmp_buf_tag __env[1], int __savemask) __attribute__ ((__nothrow__));
+//
+// With -Wall, gcc-11 warns about the disagreement unless the CPP directive
+//
+//    # 1 "/usr/include/pthread.h" 1 3 4
+//
+// appears, which appears to be witchcraft. Unfortunately, this directive is removed by the CFA preprocessor, so the
+// batchtest fails because of the spurious warning message. Hence, the warning is elided.
 extern "C" {
+#if defined(__GNUC__) && __GNUC__ == 11
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Warray-parameter"
+#endif // defined(__GNUC__) && __GNUC__ == 11
 #include_next <setjmp.h>                                                                // has internal check for multiple expansion
+#if defined(__GNUC__) && __GNUC__ == 11
+        #pragma GCC diagnostic pop
+#endif // defined(__GNUC__) && __GNUC__ == 11
 } // extern "C"
 // Local Variables: //
-// tab-width: 4 //
 // mode: c++ //
-// compile-command: "make install" //
 // End: //

src/AST/Convert.cpp

-                      r97c215f
+                      rf5a51db
 // Author           : Thierry Delisle
 // Created On       : Thu May 09 15::37::05 2019
 // Last Modified By : Andrew Beach
 // Last Modified On : Wed Jul 14 16:15:00 2021
 // Update Count     : 37
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Wed Feb  2 13:19:22 2022
+// Update Count     : 41
 //
 …
                 auto stmt = new IfStmt(
                         get<Expression>().accept1( node->cond ),
                         get<Statement>().accept1( node->thenPart ),
                         get<Statement>().accept1( node->elsePart ),
+                        get<Statement>().accept1( node->then ),
+                        get<Statement>().accept1( node->else_ ),
                         get<Statement>().acceptL( node->inits )
                 );
 …
+        }
         const ast::Stmt * visit( const ast::WhileStmt * node ) override final {
+        const ast::Stmt * visit( const ast::WhileDoStmt * node ) override final {
                 if ( inCache( node ) ) return nullptr;
                 auto inits = get<Statement>().acceptL( node->inits );
                 auto stmt = new WhileStmt(
+                auto stmt = new WhileDoStmt(
                         get<Expression>().accept1( node->cond ),
                         get<Statement>().accept1( node->body ),
+                        get<Statement>().accept1( node->else_ ),
                         inits,
                         node->isDoWhile
 …
                         get<Expression>().accept1( node->cond ),
                         get<Expression>().accept1( node->inc ),
+                        get<Statement>().accept1( node->body )
+                        get<Statement>().accept1( node->body ),
+                        get<Statement>().accept1( node->else_ )
                 );
                 return stmtPostamble( stmt, node );
 …
                         old->location,
                         GET_ACCEPT_1(condition, Expr),
                         GET_ACCEPT_1(thenPart, Stmt),
                         GET_ACCEPT_1(elsePart, Stmt),
+                        GET_ACCEPT_1(then, Stmt),
+                        GET_ACCEPT_1(else_, Stmt),
                         GET_ACCEPT_V(initialization, Stmt),
                         GET_LABELS_V(old->labels)
 …
+        }
         virtual void visit( const WhileStmt * old ) override final {
+        virtual void visit( const WhileDoStmt * old ) override final {
                 if ( inCache( old ) ) return;
                 this->node = new ast::WhileStmt(
+                this->node = new ast::WhileDoStmt(
                         old->location,
                         GET_ACCEPT_1(condition, Expr),
                         GET_ACCEPT_1(body, Stmt),
+                        GET_ACCEPT_1(else_, Stmt),
                         GET_ACCEPT_V(initialization, Stmt),
                         old->isDoWhile,
 …
                         GET_ACCEPT_1(increment, Expr),
                         GET_ACCEPT_1(body, Stmt),
+                        GET_ACCEPT_1(else_, Stmt),
                         GET_LABELS_V(old->labels)
                 );

src/AST/Copy.hpp

-                      r97c215f
+                      rf5a51db
 // Created On       : Wed Jul 10 16:13:00 2019
 // Last Modified By : Andrew Beach
 // Last Modified On : Thr Nov 11  9:22:00 2021
 // Update Count     : 2
+// Last Modified On : Wed Dec 15 11:07:00 2021
+// Update Count     : 3
 //
 …
 Node * deepCopy<Node>( const Node * localRoot );
+template<typename node_t, enum Node::ref_type ref_t>
+node_t * shallowCopy( const ptr_base<node_t, ref_t> & localRoot ) {
+        return shallowCopy( localRoot.get() );
+}
+template<typename node_t, enum Node::ref_type ref_t>
+node_t * deepCopy( const ptr_base<node_t, ref_t> & localRoot ) {
+        return deepCopy( localRoot.get() );
+}
+}

src/AST/Fwd.hpp

-                      r97c215f
+                      rf5a51db
 // Created On       : Wed May  8 16:05:00 2019
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Fri Mar 12 18:37:39 2021
 // Update Count     : 4
+// Last Modified On : Tue Feb  1 09:08:33 2022
+// Update Count     : 5
 //
 …
 class DirectiveStmt;
 class IfStmt;
 class WhileStmt;
+class WhileDoStmt;
 class ForStmt;
 class SwitchStmt;

src/AST/Node.cpp

-                      r97c215f
+                      rf5a51db
 // Created On       : Thu May 16 14:16:00 2019
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Fri Mar 12 18:25:06 2021
 // Update Count     : 2
+// Last Modified On : Tue Feb  1 09:09:39 2022
+// Update Count     : 3
 //
 …
 template class ast::ptr_base< ast::IfStmt, ast::Node::ref_type::weak >;
 template class ast::ptr_base< ast::IfStmt, ast::Node::ref_type::strong >;
 template class ast::ptr_base< ast::WhileStmt, ast::Node::ref_type::weak >;
 template class ast::ptr_base< ast::WhileStmt, ast::Node::ref_type::strong >;
+template class ast::ptr_base< ast::WhileDoStmt, ast::Node::ref_type::weak >;
+template class ast::ptr_base< ast::WhileDoStmt, ast::Node::ref_type::strong >;
 template class ast::ptr_base< ast::ForStmt, ast::Node::ref_type::weak >;
 template class ast::ptr_base< ast::ForStmt, ast::Node::ref_type::strong >;

src/AST/Node.hpp

-                      r97c215f
+                      rf5a51db
+        }
+        ptr_base & operator=( const node_t * node ) {
+                assign( node );
+                return *this;
+        }
         template<typename o_node_t>
         ptr_base & operator=( const o_node_t * node ) {

src/AST/Pass.hpp

-                      r97c215f
+                      rf5a51db
         const ast::Stmt *             visit( const ast::DirectiveStmt        * ) override final;
         const ast::Stmt *             visit( const ast::IfStmt               * ) override final;
         const ast::Stmt *             visit( const ast::WhileStmt            * ) override final;
+        const ast::Stmt *             visit( const ast::WhileDoStmt          * ) override final;
         const ast::Stmt *             visit( const ast::ForStmt              * ) override final;
         const ast::Stmt *             visit( const ast::SwitchStmt           * ) override final;
 …
 private:
+        const ast::Stmt * call_accept( const ast::Stmt * );
+        const ast::Expr * call_accept( const ast::Expr * );
+        // requests WithStmtsToAdd directly add to this statement, as if it is a compound.
+        const ast::Stmt * call_accept_as_compound(const ast::Stmt *);
+        // Regular nodes
         template< typename node_t >
+        auto call_accept( const node_t * node ) -> typename std::enable_if<
+        struct result1 {
+                bool differs;
+                const node_t * value;
+                template< typename object_t, typename super_t, typename field_t >
+                void apply(object_t *, field_t super_t::* field);
+        };
+        result1<ast::Stmt> call_accept( const ast::Stmt * );
+        result1<ast::Expr> call_accept( const ast::Expr * );
+        template< typename node_t >
+        auto call_accept( const node_t * node )
+                -> typename std::enable_if<
                                 !std::is_base_of<ast::Expr, node_t>::value &&
                                 !std::is_base_of<ast::Stmt, node_t>::value
+                        , decltype( node->accept(*this) )
+                        , result1<
+                                typename std::remove_pointer< decltype( node->accept(*this) ) >::type
+                        >
                 >::type;
+        // requests WithStmtsToAdd directly add to this statement, as if it is a compound.
+        result1<ast::Stmt> call_accept_as_compound(const ast::Stmt *);
+        template<typename it_t, template <class...> class container_t>
+                static inline void take_all_delta( it_t it, container_t<ast::ptr<ast::Decl>> * decls, bool * mutated = nullptr ) {
+                        if(empty(decls)) return;
+                        std::transform(decls->begin(), decls->end(), it, [](ast::ptr<ast::Decl>&& decl) -> auto {
+                                        auto loc = decl->location;
+                                        auto stmt = new DeclStmt( loc, decl.release() );
+                                        return { {stmt}, -1, false };
+                                });
+                        decls->clear();
+                        if(mutated) *mutated = true;
+                }
+        // Container of statements
         template< template <class...> class container_t >
+        container_t< ptr<Stmt> > call_accept( const container_t< ptr<Stmt> > & );
+        struct resultNstmt {
+                struct delta {
+                        ptr<Stmt> nval;
+                        ssize_t old_idx;
+                        bool is_old;
+                        delta(const Stmt * s, ssize_t i, bool old) : nval{s}, old_idx{i}, is_old{old} {}
+                };
+                bool differs;
+                container_t< delta > values;
+                resultNstmt() : differs(false), values{} {}
+                resultNstmt(bool diff, container_t< delta > && vals) : differs(diff), values(vals) {}
+                template< typename object_t, typename super_t, typename field_t >
+                void apply(object_t *, field_t super_t::* field);
+                template< template <class...> class incontainer_t >
+                void take_all( incontainer_t<ast::ptr<ast::Stmt>> * stmts ) {
+                        if(!stmts || stmts->empty()) return;
+                        std::transform(stmts->begin(), stmts->end(), std::back_inserter( values ), [](ast::ptr<ast::Stmt>& decl) -> delta {
+                                        return delta( decl.release(), -1, false );
+                                });
+                        stmts->clear();
+                        differs = true;
+                }
+                template< template <class...> class incontainer_t >
+                void take_all( incontainer_t<ast::ptr<ast::Decl>> * decls ) {
+                        if(!decls || decls->empty()) return;
+                        std::transform(decls->begin(), decls->end(), std::back_inserter( values ), [](ast::ptr<ast::Decl>& decl) -> auto {
+                                        auto loc = decl->location;
+                                        auto stmt = new DeclStmt( loc, decl.release() );
+                                        return delta( stmt, -1, false );
+                                });
+                        decls->clear();
+                        differs = true;
+                }
+        };
+        template< template <class...> class container_t >
+        resultNstmt<container_t> call_accept( const container_t< ptr<Stmt> > & );
+        // Container of something
         template< template <class...> class container_t, typename node_t >
+        container_t< ptr<node_t> > call_accept( const container_t< ptr<node_t> > & container );
+        struct resultN {
+                bool differs;
+                container_t<ptr<node_t>> values;
+                template< typename object_t, typename super_t, typename field_t >
+                void apply(object_t *, field_t super_t::* field);
+        };
+        template< template <class...> class container_t, typename node_t >
+        resultN< container_t, node_t > call_accept( const container_t< ptr<node_t> > & container );
 public:
         /// Logic to call the accept and mutate the parent if needed, delegates call to accept
         template<typename node_t, typename parent_t, typename child_t>
         void maybe_accept(const node_t * &, child_t parent_t::* child);
         template<typename node_t, typename parent_t, typename child_t>
         void maybe_accept_as_compound(const node_t * &, child_t parent_t::* child);
+        template<typename node_t, typename parent_t, typename field_t>
+        void maybe_accept(const node_t * &, field_t parent_t::* field);
+        template<typename node_t, typename parent_t, typename field_t>
+        void maybe_accept_as_compound(const node_t * &, field_t parent_t::* field);
 private:

src/AST/Pass.impl.hpp

-                      r97c215f
+                      rf5a51db
         __pass::previsit( core, node, 0 );
-#define VISIT( code... ) \
-        /* if this node should visit its children */ \
-        if ( __visit_children() ) { \
-                /* visit the children */ \
-                code \
+        }
 #define VISIT_END( type, node ) \
         /* call the implementation of the postvisit of this pass */ \
 …
                 template<typename it_t, template <class...> class container_t>
                 static inline void take_all( it_t it, container_t<ast::ptr<ast::Stmt>> * decls, bool * mutated = nullptr ) {
                         if(empty(decls)) return;
                         std::move(decls->begin(), decls->end(), it);
                         decls->clear();
+                static inline void take_all( it_t it, container_t<ast::ptr<ast::Stmt>> * stmts, bool * mutated = nullptr ) {
+                        if(empty(stmts)) return;
+                        std::move(stmts->begin(), stmts->end(), it);
+                        stmts->clear();
                         if(mutated) *mutated = true;
+                }
 …
                         return !new_val.empty();
+                }
+        }
+        template< typename core_t >
+        template< typename node_t >
+        template< typename object_t, typename super_t, typename field_t >
+        void ast::Pass< core_t >::result1< node_t >::apply(object_t * object, field_t super_t::* field) {
+                object->*field = value;
+        }
 …
                                 !std::is_base_of<ast::Expr, node_t>::value &&
                                 !std::is_base_of<ast::Stmt, node_t>::value
+                        , decltype( node->accept(*this) )
+                        , ast::Pass< core_t >::result1<
+                                typename std::remove_pointer< decltype( node->accept(*this) ) >::type
+                        >
                 >::type
+        {
 …
                 static_assert( !std::is_base_of<ast::Stmt, node_t>::value, "ERROR");
+                return node->accept( *this );
+                auto nval = node->accept( *this );
+                ast::Pass< core_t >::result1<
+                        typename std::remove_pointer< decltype( node->accept(*this) ) >::type
+                > res;
+                res.differs = nval != node;
+                res.value = nval;
+                return res;
+        }
         template< typename core_t >
         const ast::Expr * ast::Pass< core_t >::call_accept( const ast::Expr * expr ) {
+        ast::Pass< core_t >::result1<ast::Expr> ast::Pass< core_t >::call_accept( const ast::Expr * expr ) {
                 __pedantic_pass_assert( __visit_children() );
                 __pedantic_pass_assert( expr );
 …
+                }
+                return expr->accept( *this );
+                auto nval = expr->accept( *this );
+                return { nval != expr, nval };
+        }
         template< typename core_t >
         const ast::Stmt * ast::Pass< core_t >::call_accept( const ast::Stmt * stmt ) {
+        ast::Pass< core_t >::result1<ast::Stmt> ast::Pass< core_t >::call_accept( const ast::Stmt * stmt ) {
                 __pedantic_pass_assert( __visit_children() );
                 __pedantic_pass_assert( stmt );
+                return stmt->accept( *this );
+                const ast::Stmt * nval = stmt->accept( *this );
+                return { nval != stmt, nval };
+        }
         template< typename core_t >
         const ast::Stmt * ast::Pass< core_t >::call_accept_as_compound( const ast::Stmt * stmt ) {
+        ast::Pass< core_t >::result1<ast::Stmt> ast::Pass< core_t >::call_accept_as_compound( const ast::Stmt * stmt ) {
                 __pedantic_pass_assert( __visit_children() );
                 __pedantic_pass_assert( stmt );
 …
                 // If the pass doesn't want to add anything then we are done
                 if( empty(stmts_before) && empty(stmts_after) && empty(decls_before) && empty(decls_after) ) {
                         return nstmt;
+                        return { nstmt != stmt, nstmt };
+                }
 …
                 __pass::take_all( std::back_inserter( compound->kids ), stmts_after );
                 return compound;
+                return {true, compound};
+        }
         template< typename core_t >
         template< template <class...> class container_t >
+        container_t< ptr<Stmt> > ast::Pass< core_t >::call_accept( const container_t< ptr<Stmt> > & statements ) {
+        template< typename object_t, typename super_t, typename field_t >
+        void ast::Pass< core_t >::resultNstmt<container_t>::apply(object_t * object, field_t super_t::* field) {
+                auto & container = object->*field;
+                __pedantic_pass_assert( container.size() <= values.size() );
+                auto cit = enumerate(container).begin();
+                container_t<ptr<Stmt>> nvals;
+                for(delta & d : values) {
+                        if( d.is_old ) {
+                                __pedantic_pass_assert( cit.idx <= d.old_idx );
+                                std::advance( cit, d.old_idx - cit.idx );
+                                nvals.push_back( std::move( (*cit).val) );
+                        } else {
+                                nvals.push_back( std::move(d.nval) );
+                        }
+                }
+                object->*field = std::move(nvals);
+        }
+        template< typename core_t >
+        template< template <class...> class container_t >
+        ast::Pass< core_t >::resultNstmt<container_t> ast::Pass< core_t >::call_accept( const container_t< ptr<Stmt> > & statements ) {
                 __pedantic_pass_assert( __visit_children() );
                 if( statements.empty() ) return {};
 …
                 pass_visitor_stats.avg->push(pass_visitor_stats.depth);
+                bool mutated = false;
+                container_t< ptr<Stmt> > new_kids;
+                for( const Stmt * stmt : statements ) {
+                resultNstmt<container_t> new_kids;
+                for( auto value : enumerate( statements ) ) {
                         try {
+                                size_t i = value.idx;
+                                const Stmt * stmt = value.val;
                                 __pedantic_pass_assert( stmt );
                                 const ast::Stmt * new_stmt = stmt->accept( *this );
                                 assert( new_stmt );
                                 if(new_stmt != stmt ) mutated = true;
+                                if(new_stmt != stmt ) { new_kids.differs = true; }
                                 // Make sure that it is either adding statements or declartions but not both
 …
                                 // Take all the statements which should have gone after, N/A for first iteration
                                 __pass::take_all( std::back_inserter( new_kids ), decls_before, &mutated );
                                 __pass::take_all( std::back_inserter( new_kids ), stmts_before, &mutated );
+                                new_kids.take_all( decls_before );
+                                new_kids.take_all( stmts_before );
                                 // Now add the statement if there is one
+                                new_kids.emplace_back( new_stmt );
+                                if(new_stmt != stmt) {
+                                        new_kids.values.emplace_back( new_stmt, i, false );
+                                } else {
+                                        new_kids.values.emplace_back( nullptr, i, true );
+                                }
                                 // Take all the declarations that go before
                                 __pass::take_all( std::back_inserter( new_kids ), decls_after, &mutated );
                                 __pass::take_all( std::back_inserter( new_kids ), stmts_after, &mutated );
+                                new_kids.take_all( decls_after );
+                                new_kids.take_all( stmts_after );
+                        }
                         catch ( SemanticErrorException &e ) {
 …
                 if ( !errors.isEmpty() ) { throw errors; }
                 return mutated ? new_kids : container_t< ptr<Stmt> >();
+                return new_kids;
+        }
         template< typename core_t >
         template< template <class...> class container_t, typename node_t >
+        container_t< ast::ptr<node_t> > ast::Pass< core_t >::call_accept( const container_t< ast::ptr<node_t> > & container ) {
+        template< typename object_t, typename super_t, typename field_t >
+        void ast::Pass< core_t >::resultN<container_t, node_t>::apply(object_t * object, field_t super_t::* field) {
+                auto & container = object->*field;
+                __pedantic_pass_assert( container.size() == values.size() );
+                for(size_t i = 0; i < container.size(); i++) {
+                        // Take all the elements that are different in 'values'
+                        // and swap them into 'container'
+                        if( values[i] != nullptr ) std::swap(container[i], values[i]);
+                }
+                // Now the original containers should still have the unchanged values
+                // but also contain the new values
+        }
+        template< typename core_t >
+        template< template <class...> class container_t, typename node_t >
+        ast::Pass< core_t >::resultN<container_t, node_t> ast::Pass< core_t >::call_accept( const container_t< ast::ptr<node_t> > & container ) {
                 __pedantic_pass_assert( __visit_children() );
                 if( container.empty() ) return {};
 …
                 bool mutated = false;
                 container_t< ast::ptr<node_t> > new_kids;
+                container_t<ptr<node_t>> new_kids;
                 for ( const node_t * node : container ) {
                         try {
                                 __pedantic_pass_assert( node );
                                 const node_t * new_stmt = strict_dynamic_cast< const node_t * >( node->accept( *this ) );
+                                if(new_stmt != node ) mutated = true;
+                                new_kids.emplace_back( new_stmt );
+                                if(new_stmt != node ) {
+                                        mutated = true;
+                                        new_kids.emplace_back( new_stmt );
+                                } else {
+                                        new_kids.emplace_back( nullptr );
+                                }
+                        }
                         catch( SemanticErrorException &e ) {
 …
+                        }
+                }
+                __pedantic_pass_assert( new_kids.size() == container.size() );
                 pass_visitor_stats.depth--;
                 if ( ! errors.isEmpty() ) { throw errors; }
                 return mutated ? new_kids : container_t< ast::ptr<node_t> >();
+                return ast::Pass< core_t >::resultN<container_t, node_t>{ mutated,  new_kids };
+        }
 …
                 auto new_val = call_accept( old_val );
                 static_assert( !std::is_same<const ast::Node *, decltype(new_val)>::value || std::is_same<int, decltype(old_val)>::value, "ERROR");
                 if( __pass::differs(old_val, new_val) ) {
+                static_assert( !std::is_same<const ast::Node *, decltype(new_val)>::value /* || std::is_same<int, decltype(old_val)>::value */, "ERROR");
+                if( new_val.differs ) {
                         auto new_parent = __pass::mutate<core_t>(parent);
                         new_parent->*child = new_val;
+                        new_val.apply(new_parent, child);
                         parent = new_parent;
+                }
 …
                 static_assert( !std::is_same<const ast::Node *, decltype(new_val)>::value || std::is_same<int, decltype(old_val)>::value, "ERROR");
                 if( __pass::differs(old_val, new_val) ) {
+                if( new_val.differs ) {
                         auto new_parent = __pass::mutate<core_t>(parent);
                         new_parent->*child = new_val;
+                        new_val.apply( new_parent, child );
                         parent = new_parent;
+                }
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
 …
                 maybe_accept( node, &ObjectDecl::bitfieldWidth );
                 maybe_accept( node, &ObjectDecl::attributes    );
+        )
+        }
         __pass::symtab::addId( core, 0, node );
 …
         __pass::symtab::addId( core, 0, node );
+        VISIT(maybe_accept( node, &FunctionDecl::withExprs );)
+        if ( __visit_children() ) {
+                maybe_accept( node, &FunctionDecl::withExprs );
+        }
+        {
                 // with clause introduces a level of scope (for the with expression members).
 …
                         } };
                         __pass::symtab::addId( core, 0, func );
                         VISIT(
+                        if ( __visit_children() ) {
                                 // parameter declarations
                                 maybe_accept( node, &FunctionDecl::params );
 …
                                 maybe_accept( node, &FunctionDecl::stmts );
                                 maybe_accept( node, &FunctionDecl::attributes );
+                        )
+                        }
+                }
+        }
 …
         __pass::symtab::addStructFwd( core, 0, node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { * this };
                 maybe_accept( node, &StructDecl::params     );
                 maybe_accept( node, &StructDecl::members    );
                 maybe_accept( node, &StructDecl::attributes );
         })
+        }
         // this addition replaces the forward declaration
 …
         __pass::symtab::addUnionFwd( core, 0, node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { * this };
                 maybe_accept( node, &UnionDecl::params     );
                 maybe_accept( node, &UnionDecl::members    );
                 maybe_accept( node, &UnionDecl::attributes );
         })
+        }
         __pass::symtab::addUnion( core, 0, node );
 …
         __pass::symtab::addEnum( core, 0, node );
         VISIT(
+        if ( __visit_children() ) {
                 // unlike structs, traits, and unions, enums inject their members into the global scope
                 maybe_accept( node, &EnumDecl::params     );
                 maybe_accept( node, &EnumDecl::members    );
                 maybe_accept( node, &EnumDecl::attributes );
+        )
+        }
         VISIT_END( Decl, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &TraitDecl::params     );
                 maybe_accept( node, &TraitDecl::members    );
                 maybe_accept( node, &TraitDecl::attributes );
         })
+        }
         __pass::symtab::addTrait( core, 0, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &TypeDecl::base   );
         })
+        }
         // see A NOTE ON THE ORDER OF TRAVERSAL, above
 …
         __pass::symtab::addType( core, 0, node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &TypeDecl::assertions );
 …
                         maybe_accept( node, &TypeDecl::init );
+                }
+        )
+        }
         VISIT_END( Decl, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &TypedefDecl::base   );
         })
+        }
         __pass::symtab::addType( core, 0, node );
+        VISIT( maybe_accept( node, &TypedefDecl::assertions ); )
+        if ( __visit_children() ) {
+                maybe_accept( node, &TypedefDecl::assertions );
+        }
         VISIT_END( Decl, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &AsmDecl::stmt );
+        )
+        }
         VISIT_END( AsmDecl, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &DirectiveDecl::stmt );
+        )
+        }
         VISIT_END( DirectiveDecl, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &StaticAssertDecl::cond );
                 maybe_accept( node, &StaticAssertDecl::msg  );
+        )
+        }
         VISIT_END( StaticAssertDecl, node );
 …
 const ast::CompoundStmt * ast::Pass< core_t >::visit( const ast::CompoundStmt * node ) {
         VISIT_START( node );
+        VISIT(
+        if ( __visit_children() ) {
                 // Do not enter (or leave) a new scope if atFunctionTop. Remember to save the result.
                 auto guard1 = makeFuncGuard( [this, enterScope = !this->atFunctionTop]() {
 …
                 guard_scope guard3 { *this };
                 maybe_accept( node, &CompoundStmt::kids );
+        )
+        }
         VISIT_END( CompoundStmt, node );
+}
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ExprStmt::expr );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node )
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &AsmStmt::instruction );
                 maybe_accept( node, &AsmStmt::output      );
                 maybe_accept( node, &AsmStmt::input       );
                 maybe_accept( node, &AsmStmt::clobber     );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 // if statements introduce a level of scope (for the initialization)
                 guard_symtab guard { *this };
                 maybe_accept( node, &IfStmt::inits    );
                 maybe_accept( node, &IfStmt::cond     );
                 maybe_accept_as_compound( node, &IfStmt::thenPart );
                 maybe_accept_as_compound( node, &IfStmt::elsePart );
         })
+                maybe_accept_as_compound( node, &IfStmt::then );
+                maybe_accept_as_compound( node, &IfStmt::else_ );
+        }
         VISIT_END( Stmt, node );
 …
 //--------------------------------------------------------------------------
 // WhileStmt
 template< typename core_t >
 const ast::Stmt * ast::Pass< core_t >::visit( const ast::WhileStmt * node ) {
         VISIT_START( node );
         VISIT({
+// WhileDoStmt
+template< typename core_t >
+const ast::Stmt * ast::Pass< core_t >::visit( const ast::WhileDoStmt * node ) {
+        VISIT_START( node );
+        if ( __visit_children() ) {
                 // while statements introduce a level of scope (for the initialization)
                 guard_symtab guard { *this };
                 maybe_accept( node, &WhileStmt::inits );
                 maybe_accept( node, &WhileStmt::cond  );
                 maybe_accept_as_compound( node, &WhileStmt::body  );
         })
+                maybe_accept( node, &WhileDoStmt::inits );
+                maybe_accept( node, &WhileDoStmt::cond  );
+                maybe_accept_as_compound( node, &WhileDoStmt::body  );
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 // for statements introduce a level of scope (for the initialization)
                 guard_symtab guard { *this };
 …
                 maybe_accept( node, &ForStmt::inc   );
                 maybe_accept_as_compound( node, &ForStmt::body  );
         })
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &SwitchStmt::cond  );
                 maybe_accept( node, &SwitchStmt::stmts );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &CaseStmt::cond  );
                 maybe_accept( node, &CaseStmt::stmts );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ReturnStmt::expr );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ThrowStmt::expr   );
                 maybe_accept( node, &ThrowStmt::target );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &TryStmt::body     );
                 maybe_accept( node, &TryStmt::handlers );
                 maybe_accept( node, &TryStmt::finally  );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 // catch statements introduce a level of scope (for the caught exception)
                 guard_symtab guard { *this };
 …
                 maybe_accept( node, &CatchStmt::cond );
                 maybe_accept_as_compound( node, &CatchStmt::body );
         })
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &FinallyStmt::body );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &SuspendStmt::then   );
+        )
+        }
         VISIT_END( Stmt, node );
 …
                 // }
         VISIT({
+        if ( __visit_children() ) {
                 std::vector<WaitForStmt::Clause> new_clauses;
                 new_clauses.reserve( node->clauses.size() );
 …
                         const Expr * func = clause.target.func ? clause.target.func->accept(*this) : nullptr;
                         if(func != clause.target.func) mutated = true;
+                        else func = nullptr;
                         std::vector<ptr<Expr>> new_args;
 …
                         for( const auto & arg : clause.target.args ) {
                                 auto a = arg->accept(*this);
+                                new_args.push_back( a );
+                                if( a != arg ) mutated = true;
+                                if( a != arg ) {
+                                        mutated = true;
+                                        new_args.push_back( a );
+                                } else
+                                        new_args.push_back( nullptr );
+                        }
                         const Stmt * stmt = clause.stmt ? clause.stmt->accept(*this) : nullptr;
                         if(stmt != clause.stmt) mutated = true;
+                        else stmt = nullptr;
                         const Expr * cond = clause.cond ? clause.cond->accept(*this) : nullptr;
                         if(cond != clause.cond) mutated = true;
+                        else cond = nullptr;
                         new_clauses.push_back( WaitForStmt::Clause{ {func, std::move(new_args) }, stmt, cond } );
 …
                 if(mutated) {
                         auto n = __pass::mutate<core_t>(node);
+                        n->clauses = std::move( new_clauses );
+                        for(size_t i = 0; i < new_clauses.size(); i++) {
+                                if(new_clauses.at(i).target.func != nullptr) std::swap(n->clauses.at(i).target.func, new_clauses.at(i).target.func);
+                                for(size_t j = 0; j < new_clauses.at(i).target.args.size(); j++) {
+                                        if(new_clauses.at(i).target.args.at(j) != nullptr) std::swap(n->clauses.at(i).target.args.at(j), new_clauses.at(i).target.args.at(j));
+                                }
+                                if(new_clauses.at(i).stmt != nullptr) std::swap(n->clauses.at(i).stmt, new_clauses.at(i).stmt);
+                                if(new_clauses.at(i).cond != nullptr) std::swap(n->clauses.at(i).cond, new_clauses.at(i).cond);
+                        }
                         node = n;
+                }
         })
+        }
         #define maybe_accept(field) \
                 if(node->field) { \
                         auto nval = call_accept( node->field ); \
                         if(nval != node->field ) { \
+                        if(nval.differs ) { \
                                 auto nparent = __pass::mutate<core_t>(node); \
                                 nparent->field = nval; \
+                                nparent->field = nval.value; \
                                 node = nparent; \
                         } \
+                }
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( timeout.time );
                 maybe_accept( timeout.stmt );
 …
                 maybe_accept( orElse.stmt  );
                 maybe_accept( orElse.cond  );
+        )
+        }
         #undef maybe_accept
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &WithStmt::exprs );
+                {
 …
                         maybe_accept( node, &WithStmt::stmt );
+                }
+        )
+        }
         VISIT_END( Stmt, node );
+}
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &DeclStmt::decl );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         // For now this isn't visited, it is unclear if this causes problem
         // if all tests are known to pass, remove this code
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ImplicitCtorDtorStmt::callStmt );
+        )
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 // mutex statements introduce a level of scope (for the initialization)
                 guard_symtab guard { *this };
                 maybe_accept( node, &MutexStmt::stmt );
                 maybe_accept( node, &MutexStmt::mutexObjs );
         })
+        }
         VISIT_END( Stmt, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
 …
                 maybe_accept( node, &ApplicationExpr::func );
                 maybe_accept( node, &ApplicationExpr::args );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
 …
                 maybe_accept( node, &UntypedExpr::args );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &NameExpr::result );
         })
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &CastExpr::result );
+                }
                 maybe_accept( node, &CastExpr::arg );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &KeywordCastExpr::result );
+                }
                 maybe_accept( node, &KeywordCastExpr::arg );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &VirtualCastExpr::result );
+                }
                 maybe_accept( node, &VirtualCastExpr::arg );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &AddressExpr::result );
+                }
                 maybe_accept( node, &AddressExpr::arg );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &LabelAddressExpr::result );
         })
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &UntypedMemberExpr::result );
 …
                 maybe_accept( node, &UntypedMemberExpr::aggregate );
                 maybe_accept( node, &UntypedMemberExpr::member    );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &MemberExpr::result );
+                }
                 maybe_accept( node, &MemberExpr::aggregate );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &VariableExpr::result );
         })
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &ConstantExpr::result );
         })
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &SizeofExpr::result );
 …
                         maybe_accept( node, &SizeofExpr::expr );
+                }
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &AlignofExpr::result );
 …
                         maybe_accept( node, &AlignofExpr::expr );
+                }
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &UntypedOffsetofExpr::result );
+                }
                 maybe_accept( node, &UntypedOffsetofExpr::type   );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &OffsetofExpr::result );
+                }
                 maybe_accept( node, &OffsetofExpr::type   );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &OffsetPackExpr::result );
+                }
                 maybe_accept( node, &OffsetPackExpr::type   );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &LogicalExpr::result );
 …
                 maybe_accept( node, &LogicalExpr::arg1 );
                 maybe_accept( node, &LogicalExpr::arg2 );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &ConditionalExpr::result );
 …
                 maybe_accept( node, &ConditionalExpr::arg2 );
                 maybe_accept( node, &ConditionalExpr::arg3 );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &CommaExpr::result );
 …
                 maybe_accept( node, &CommaExpr::arg1 );
                 maybe_accept( node, &CommaExpr::arg2 );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &TypeExpr::result );
+                }
                 maybe_accept( node, &TypeExpr::type );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &AsmExpr::result );
 …
                 maybe_accept( node, &AsmExpr::constraint );
                 maybe_accept( node, &AsmExpr::operand    );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &ImplicitCopyCtorExpr::result );
+                }
                 maybe_accept( node, &ImplicitCopyCtorExpr::callExpr    );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &ConstructorExpr::result );
+                }
                 maybe_accept( node, &ConstructorExpr::callExpr );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &CompoundLiteralExpr::result );
+                }
                 maybe_accept( node, &CompoundLiteralExpr::init );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &RangeExpr::result );
 …
                 maybe_accept( node, &RangeExpr::low    );
                 maybe_accept( node, &RangeExpr::high   );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &UntypedTupleExpr::result );
+                }
                 maybe_accept( node, &UntypedTupleExpr::exprs  );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &TupleExpr::result );
+                }
                 maybe_accept( node, &TupleExpr::exprs  );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &TupleIndexExpr::result );
+                }
                 maybe_accept( node, &TupleIndexExpr::tuple  );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &TupleAssignExpr::result );
+                }
                 maybe_accept( node, &TupleAssignExpr::stmtExpr );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT(// don't want statements from outer CompoundStmts to be added to this StmtExpr
+        if ( __visit_children() ) {
+                // don't want statements from outer CompoundStmts to be added to this StmtExpr
                 // get the stmts that will need to be spliced in
                 auto stmts_before = __pass::stmtsToAddBefore( core, 0);
 …
                 maybe_accept( node, &StmtExpr::returnDecls );
                 maybe_accept( node, &StmtExpr::dtors       );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &UniqueExpr::result );
+                }
                 maybe_accept( node, &UniqueExpr::expr   );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &UntypedInitExpr::result );
 …
                 maybe_accept( node, &UntypedInitExpr::expr   );
                 // not currently visiting initAlts, but this doesn't matter since this node is only used in the resolver.
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &InitExpr::result );
 …
                 maybe_accept( node, &InitExpr::expr   );
                 maybe_accept( node, &InitExpr::designation );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &DeletedExpr::result );
 …
                 maybe_accept( node, &DeletedExpr::expr );
                 // don't visit deleteStmt, because it is a pointer to somewhere else in the tree.
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &DefaultArgExpr::result );
+                }
                 maybe_accept( node, &DefaultArgExpr::expr );
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
+        VISIT({
+        if ( __visit_children() ) {
+                {
                         guard_symtab guard { *this };
                         maybe_accept( node, &GenericExpr::result );
 …
                         node = n;
+                }
+        )
+        }
         VISIT_END( Expr, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 // xxx - should PointerType visit/mutate dimension?
                 maybe_accept( node, &PointerType::base );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ArrayType::dimension );
                 maybe_accept( node, &ArrayType::base );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ReferenceType::base );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &QualifiedType::parent );
                 maybe_accept( node, &QualifiedType::child );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 // guard_forall_subs forall_guard { *this, node };
                 // mutate_forall( node );
 …
                 maybe_accept( node, &FunctionType::returns );
                 maybe_accept( node, &FunctionType::params  );
         })
+        }
         VISIT_END( Type, node );
 …
         __pass::symtab::addStruct( core, 0, node->name );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &StructInstType::params );
         })
+        }
         VISIT_END( Type, node );
 …
         __pass::symtab::addUnion( core, 0, node->name );
         VISIT({
+        if ( __visit_children() ) {
                 guard_symtab guard { *this };
                 maybe_accept( node, &UnionInstType::params );
         })
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 maybe_accept( node, &EnumInstType::params );
         })
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT({
+        if ( __visit_children() ) {
                 maybe_accept( node, &TraitInstType::params );
         })
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
+                {
                         maybe_accept( node, &TypeInstType::params );
 …
                 // ensure that base re-bound if doing substitution
                 __pass::forall::replace( core, 0, node );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &TupleType::types );
                 maybe_accept( node, &TupleType::members );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &TypeofType::expr );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &VTableType::base );
+        )
+        }
         VISIT_END( Type, node );
 …
         VISIT_START( node );
+        VISIT( maybe_accept( node, &Designation::designators ); )
+        if ( __visit_children() ) {
+                maybe_accept( node, &Designation::designators );
+        }
         VISIT_END( Designation, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &SingleInit::value );
+        )
+        }
         VISIT_END( Init, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ListInit::designations );
                 maybe_accept( node, &ListInit::initializers );
+        )
+        }
         VISIT_END( Init, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &ConstructorInit::ctor );
                 maybe_accept( node, &ConstructorInit::dtor );
                 maybe_accept( node, &ConstructorInit::init );
+        )
+        }
         VISIT_END( Init, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
                 maybe_accept( node, &Attribute::params );
+        )
+        }
         VISIT_END( Attribute, node );
 …
         VISIT_START( node );
         VISIT(
+        if ( __visit_children() ) {
+                {
                         bool mutated = false;
 …
+                        }
+                }
+        )
+        }
         VISIT_END( TypeSubstitution, node );
 …
 #undef VISIT_START
-#undef VISIT
 #undef VISIT_END

src/AST/Print.cpp

-                      r97c215f
+                      rf5a51db
                 print( node->funcSpec );
+                if ( node->type ) {
+                if ( node->type && node->isTypeFixed ) {
                         node->type->accept( *this );
                 } else {
+                        os << "untyped entity";
+                        if (!node->type_params.empty()) {
+                                os << "forall" << endl;
+                                ++indent;
+                                printAll(node->type_params);
+                                os << indent;
+                                --indent;
+                                if (!node->assertions.empty()) {
+                                        os << "with assertions" << endl;
+                                        ++indent;
+                                        printAll(node->assertions);
+                                        os << indent;
+                                        --indent;
+                                }
+                        }
+                        os << "function" << endl;
+                        if ( ! node->params.empty() ) {
+                                os << indent << "... with parameters" << endl;
+                                ++indent;
+                                printAll( node->params );
+                                if ( node->type->isVarArgs ) {
+                                        os << indent << "and a variable number of other arguments" << endl;
+                                }
+                                --indent;
+                        } else if ( node->type->isVarArgs ) {
+                                os << indent+1 << "accepting unspecified arguments" << endl;
+                        }
+                        os << indent << "... returning";
+                        if ( node->returns.empty() ) {
+                                os << " nothing" << endl;
+                        } else {
+                                os << endl;
+                                ++indent;
+                                printAll( node->returns );
+                                --indent;
+                        }
+                }
 …
                 ++indent;
                 os << indent;
                 safe_print( node->thenPart );
                 --indent;
                 if ( node->elsePart != 0 ) {
+                safe_print( node->then );
+                --indent;
+                if ( node->else_ != 0 ) {
                         os << indent << "... else:" << endl;
                         ++indent;
                         os << indent;
                         node->elsePart->accept( *this );
+                        node->else_->accept( *this );
                         --indent;
                 } // if
 …
+        }
         virtual const ast::Stmt * visit( const ast::WhileStmt * node ) override final {
+        virtual const ast::Stmt * visit( const ast::WhileDoStmt * node ) override final {
                 if ( node->isDoWhile ) { os << "Do-"; }
                 os << "While on condition:" << endl;

src/AST/Stmt.cpp

-                      r97c215f
+                      rf5a51db
 // Author           : Aaron B. Moss
 // Created On       : Wed May  8 13:00:00 2019
 // Last Modified By : Andrew Beach
 // Last Modified On : Wed May 15 15:53:00 2019
 // Update Count     : 2
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Wed Feb  2 19:01:20 2022
+// Update Count     : 3
 //
 …
 // --- BranchStmt
 BranchStmt::BranchStmt( const CodeLocation& loc, Kind kind, Label target, std::vector<Label>&& labels )
 : Stmt(loc, std::move(labels)), originalTarget(target), target(target), kind(kind) {
+BranchStmt::BranchStmt( const CodeLocation& loc, Kind kind, Label target, const std::vector<Label>&& labels )
+                : Stmt(loc, std::move(labels)), originalTarget(target), target(target), kind(kind) {
         // Make sure a syntax error hasn't slipped through.
         assert( Goto != kind || !target.empty() );

src/AST/Stmt.hpp

-                      r97c215f
+                      rf5a51db
 // Author           : Aaron B. Moss
 // Created On       : Wed May  8 13:00:00 2019
 // Last Modified By : Andrew Beach
 // Last Modified On : Fri May 17 12:45:00 2019
 // Update Count     : 5
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Wed Feb  2 20:06:41 2022
+// Update Count     : 34
 //
 …
 #include <list>
 #include <utility>                // for move
+#include <utility>                                                                              // for move
 #include <vector>
 #include "Label.hpp"
 #include "Node.hpp"               // for node, ptr
+#include "Node.hpp"                                                                             // for node, ptr
 #include "ParseNode.hpp"
 #include "Visitor.hpp"
 …
 // Must be included in *all* AST classes; should be #undef'd at the end of the file
 #define MUTATE_FRIEND \
+#define MUTATE_FRIEND                                                                                                   \
     template<typename node_t> friend node_t * mutate(const node_t * node); \
         template<typename node_t> friend node_t * shallowCopy(const node_t * node);
 namespace ast {
 class Expr;
 /// Base statement node
+// Base statement node
 class Stmt : public ParseNode {
 public:
+  public:
         std::vector<Label> labels;
         Stmt( const CodeLocation & loc, std::vector<Label> && labels = {} )
         : ParseNode(loc), labels(std::move(labels)) {}
         Stmt(const Stmt& o) : ParseNode(o), labels(o.labels) {}
+        Stmt( const CodeLocation & loc, const std::vector<Label> && labels = {} )
+                : ParseNode(loc), labels(std::move(labels)) {}
+        Stmt(const Stmt & o) : ParseNode(o), labels(o.labels) {}
         const Stmt * accept( Visitor & v ) const override = 0;
 private:
+  private:
         Stmt * clone() const override = 0;
         MUTATE_FRIEND
 };
 /// Compound statement `{ ... }`
+// Compound statement: { ... }
 class CompoundStmt final : public Stmt {
 public:
+  public:
         std::list<ptr<Stmt>> kids;
+        CompoundStmt(const CodeLocation & loc, std::list<ptr<Stmt>> && ks = {},
+                std::vector<Label>&& labels = {} )
+        : Stmt(loc, std::move(labels)), kids(std::move(ks)) {}
+        CompoundStmt( const CompoundStmt& o );
+        CompoundStmt( CompoundStmt&& o ) = default;
+        CompoundStmt(const CodeLocation & loc, const std::list<ptr<Stmt>> && ks = {}, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), kids(std::move(ks)) {}
+        CompoundStmt( const CompoundStmt & o );
+        CompoundStmt( CompoundStmt && o ) = default;
         void push_back( const Stmt * s ) { kids.emplace_back( s ); }
 …
         const CompoundStmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+  private:
         CompoundStmt * clone() const override { return new CompoundStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Empty statment `;`
+// Empty statment: ;
 class NullStmt final : public Stmt {
 public:
         NullStmt( const CodeLocation & loc, std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)) {}
+  public:
+        NullStmt( const CodeLocation & loc, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)) {}
         const NullStmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+  private:
         NullStmt * clone() const override { return new NullStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Expression wrapped by statement
+// Expression wrapped by statement
 class ExprStmt final : public Stmt {
 public:
+  public:
         ptr<Expr> expr;
         ExprStmt( const CodeLocation& loc, const Expr* e, std::vector<Label>&& labels = {} )
         : Stmt(loc, std::move(labels)), expr(e) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        ExprStmt( const CodeLocation & loc, const Expr* e, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), expr(e) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         ExprStmt * clone() const override { return new ExprStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Assembly statement `asm ... ( "..." : ... )`
+// Assembly statement: asm ... ( "..." : ... )
 class AsmStmt final : public Stmt {
 public:
+  public:
         bool isVolatile;
         ptr<Expr> instruction;
 …
         AsmStmt( const CodeLocation & loc, bool isVolatile, const Expr * instruction,
                 std::vector<ptr<Expr>> && output, std::vector<ptr<Expr>> && input,
                 std::vector<ptr<ConstantExpr>> && clobber, std::vector<Label> && gotoLabels,
                 std::vector<Label> && labels = {})
         : Stmt(loc, std::move(labels)), isVolatile(isVolatile), instruction(instruction),
           output(std::move(output)), input(std::move(input)), clobber(std::move(clobber)),
           gotoLabels(std::move(gotoLabels)) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+                         const std::vector<ptr<Expr>> && output, const std::vector<ptr<Expr>> && input,
+                         const std::vector<ptr<ConstantExpr>> && clobber, const std::vector<Label> && gotoLabels,
+                         const std::vector<Label> && labels = {})
+                : Stmt(loc, std::move(labels)), isVolatile(isVolatile), instruction(instruction),
+                  output(std::move(output)), input(std::move(input)), clobber(std::move(clobber)),
+                  gotoLabels(std::move(gotoLabels)) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         AsmStmt * clone() const override { return new AsmStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// C-preprocessor directive `#...`
+// C-preprocessor directive: #...
 class DirectiveStmt final : public Stmt {
 public:
+  public:
         std::string directive;
         DirectiveStmt( const CodeLocation & loc, const std::string & directive,
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), directive(directive) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+                                   std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), directive(directive) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         DirectiveStmt * clone() const override { return new DirectiveStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// If conditional statement `if (...) ... else ...`
+// If statement: if (...) ... else ...
 class IfStmt final : public Stmt {
 public:
         ptr<Expr> cond;
         ptr<Stmt> thenPart;
         ptr<Stmt> elsePart;
+  public:
+        ptr<Expr> cond;
+        ptr<Stmt> then;
+        ptr<Stmt> else_;
         std::vector<ptr<Stmt>> inits;
         IfStmt( const CodeLocation & loc, const Expr * cond, const Stmt * thenPart,
                 const Stmt * elsePart = nullptr, std::vector<ptr<Stmt>> && inits = {},
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), cond(cond), thenPart(thenPart), elsePart(elsePart),
           inits(std::move(inits)) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        IfStmt( const CodeLocation & loc, const Expr * cond, const Stmt * then,
+                        const Stmt * else_ = nullptr, const std::vector<ptr<Stmt>> && inits = {},
+                        const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), cond(cond), then(then), else_(else_),
+                  inits(std::move(inits)) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         IfStmt * clone() const override { return new IfStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Switch or choose conditional statement `switch (...) { ... }`
+// Switch or choose statement: switch (...) { ... }
 class SwitchStmt final : public Stmt {
 public:
+  public:
         ptr<Expr> cond;
         std::vector<ptr<Stmt>> stmts;
         SwitchStmt( const CodeLocation & loc, const Expr * cond, std::vector<ptr<Stmt>> && stmts,
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), cond(cond), stmts(std::move(stmts)) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        SwitchStmt( const CodeLocation & loc, const Expr * cond, const std::vector<ptr<Stmt>> && stmts,
+                                const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), cond(cond), stmts(std::move(stmts)) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         SwitchStmt * clone() const override { return new SwitchStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Case label `case ...:` `default:`
+// Case label: case ...: or default:
 class CaseStmt final : public Stmt {
 public:
         /// Null for the default label.
+  public:
+        // Null for the default label.
         ptr<Expr> cond;
         std::vector<ptr<Stmt>> stmts;
         CaseStmt( const CodeLocation & loc, const Expr * cond, std::vector<ptr<Stmt>> && stmts,
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), cond(cond), stmts(std::move(stmts)) {}
+        CaseStmt( const CodeLocation & loc, const Expr * cond, const std::vector<ptr<Stmt>> && stmts,
+                          const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), cond(cond), stmts(std::move(stmts)) {}
         bool isDefault() const { return !cond; }
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+  private:
         CaseStmt * clone() const override { return new CaseStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// While loop `while (...) ...` `do ... while (...);
 class WhileStmt final : public Stmt {
 public:
+// While loop: while (...) ... else ... or do ... while (...) else ...;
+class WhileDoStmt final : public Stmt {
+  public:
         ptr<Expr> cond;
         ptr<Stmt> body;
+        ptr<Stmt> else_;
         std::vector<ptr<Stmt>> inits;
         bool isDoWhile;
+        WhileStmt( const CodeLocation & loc, const Expr * cond, const Stmt * body,
+                std::vector<ptr<Stmt>> && inits, bool isDoWhile = false, std::vector<Label> && labels = {} )
+        : Stmt(loc, std::move(labels)), cond(cond), body(body), inits(std::move(inits)),
+          isDoWhile(isDoWhile) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+private:
+        WhileStmt * clone() const override { return new WhileStmt{ *this }; }
+        MUTATE_FRIEND
+};
+/// For loop `for (... ; ... ; ...) ...`
+        WhileDoStmt( const CodeLocation & loc, const Expr * cond, const Stmt * body,
+                                 const std::vector<ptr<Stmt>> && inits, bool isDoWhile = false, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), cond(cond), body(body), else_(nullptr), inits(std::move(inits)), isDoWhile(isDoWhile) {}
+        WhileDoStmt( const CodeLocation & loc, const Expr * cond, const Stmt * body, const Stmt * else_,
+                                 const std::vector<ptr<Stmt>> && inits, bool isDoWhile = false, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), cond(cond), body(body), else_(else_), inits(std::move(inits)), isDoWhile(isDoWhile) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
+        WhileDoStmt * clone() const override { return new WhileDoStmt{ *this }; }
+        MUTATE_FRIEND
+};
+// For loop: for (... ; ... ; ...) ... else ...
 class ForStmt final : public Stmt {
 public:
+  public:
         std::vector<ptr<Stmt>> inits;
         ptr<Expr> cond;
         ptr<Expr> inc;
         ptr<Stmt> body;
+        ForStmt( const CodeLocation & loc, std::vector<ptr<Stmt>> && inits, const Expr * cond,
+                const Expr * inc, const Stmt * body, std::vector<Label> && labels = {} )
+        : Stmt(loc, std::move(labels)), inits(std::move(inits)), cond(cond), inc(inc),
+          body(body) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+private:
+        ptr<Stmt> else_;
+        ForStmt( const CodeLocation & loc, const std::vector<ptr<Stmt>> && inits, const Expr * cond,
+                         const Expr * inc, const Stmt * body, const std::vector<Label> && label = {} )
+                : Stmt(loc, std::move(label)), inits(std::move(inits)), cond(cond), inc(inc), body(body), else_(nullptr) {}
+        ForStmt( const CodeLocation & loc, const std::vector<ptr<Stmt>> && inits, const Expr * cond,
+                         const Expr * inc, const Stmt * body, const Stmt * else_, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), inits(std::move(inits)), cond(cond), inc(inc), body(body), else_(else_) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         ForStmt * clone() const override { return new ForStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Branch control flow statement `goto ...` `break` `continue` `fallthru`
+// Branch control flow statement: goto ... or break or continue or fallthru
 class BranchStmt final : public Stmt {
 public:
+  public:
         enum Kind { Goto, Break, Continue, FallThrough, FallThroughDefault };
         static constexpr size_t kindEnd = 1 + (size_t)FallThroughDefault;
 …
         Kind kind;
+        BranchStmt( const CodeLocation & loc, Kind kind, Label target,
+                std::vector<Label> && labels = {} );
+        BranchStmt( const CodeLocation & loc, const Expr * computedTarget,
+                std::vector<Label> && labels = {} )
+        : Stmt(loc, std::move(labels)), originalTarget(loc), target(loc),
+          computedTarget(computedTarget), kind(Goto) {}
+        BranchStmt( const CodeLocation & loc, Kind kind, Label target, const std::vector<Label> && labels = {} );
+        BranchStmt( const CodeLocation & loc, const Expr * computedTarget, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), originalTarget(loc), target(loc), computedTarget(computedTarget), kind(Goto) {}
         const char * kindName() const { return kindNames[kind]; }
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+  private:
         BranchStmt * clone() const override { return new BranchStmt{ *this }; }
         MUTATE_FRIEND
 …
 };
 /// Return statement `return ...`
+// Return statement: return ...
 class ReturnStmt final : public Stmt {
 public:
+  public:
         ptr<Expr> expr;
         ReturnStmt( const CodeLocation & loc, const Expr * expr, std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), expr(expr) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        ReturnStmt( const CodeLocation & loc, const Expr * expr, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), expr(expr) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         ReturnStmt * clone() const override { return new ReturnStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Kind of exception
+// Kind of exception
 enum ExceptionKind { Terminate, Resume };
 /// Throw statement `throw ...`
+// Throw statement: throw ...
 class ThrowStmt final : public Stmt {
 public:
+  public:
         ptr<Expr> expr;
         ptr<Expr> target;
         ExceptionKind kind;
+        ThrowStmt(
+                const CodeLocation & loc, ExceptionKind kind, const Expr * expr, const Expr * target,
+                std::vector<Label> && labels = {} )
+        : Stmt(loc, std::move(labels)), expr(expr), target(target), kind(kind) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+private:
+        ThrowStmt( const CodeLocation & loc, ExceptionKind kind, const Expr * expr,
+                           const Expr * target, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), expr(expr), target(target), kind(kind) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         ThrowStmt * clone() const override { return new ThrowStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Try statement `try { ... } ...`
+// Try statement: try { ... } ...
 class TryStmt final : public Stmt {
 public:
+  public:
         ptr<CompoundStmt> body;
         std::vector<ptr<CatchStmt>> handlers;
         ptr<FinallyStmt> finally;
+        TryStmt(
+                const CodeLocation & loc, const CompoundStmt * body,
+                std::vector<ptr<CatchStmt>> && handlers, const FinallyStmt * finally,
+                std::vector<Label> && labels = {} )
+        : Stmt(loc, std::move(labels)), body(body), handlers(std::move(handlers)), finally(finally) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+private:
+        TryStmt( const CodeLocation & loc, const CompoundStmt * body,
+                         const std::vector<ptr<CatchStmt>> && handlers, const FinallyStmt * finally,
+                         const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), body(body), handlers(std::move(handlers)), finally(finally) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         TryStmt * clone() const override { return new TryStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Catch clause of try statement
+// Catch clause of try statement
 class CatchStmt final : public Stmt {
 public:
+  public:
         ptr<Decl> decl;
         ptr<Expr> cond;
 …
         ExceptionKind kind;
+        CatchStmt(
+                const CodeLocation & loc, ExceptionKind kind, const Decl * decl, const Expr * cond,
+                const Stmt * body, std::vector<Label> && labels = {} )
+        : Stmt(loc, std::move(labels)), decl(decl), cond(cond), body(body), kind(kind) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+private:
+        CatchStmt( const CodeLocation & loc, ExceptionKind kind, const Decl * decl, const Expr * cond,
+                           const Stmt * body, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), decl(decl), cond(cond), body(body), kind(kind) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         CatchStmt * clone() const override { return new CatchStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Finally clause of try statement
+// Finally clause of try statement
 class FinallyStmt final : public Stmt {
 public:
+  public:
         ptr<CompoundStmt> body;
         FinallyStmt( const CodeLocation & loc, const CompoundStmt * body,
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), body(body) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+                                 std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), body(body) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         FinallyStmt * clone() const override { return new FinallyStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Suspend statement
+// Suspend statement
 class SuspendStmt final : public Stmt {
 public:
+  public:
         ptr<CompoundStmt> then;
         enum Type { None, Coroutine, Generator } type = None;
         SuspendStmt( const CodeLocation & loc, const CompoundStmt * then, Type type, std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), then(then), type(type) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        SuspendStmt( const CodeLocation & loc, const CompoundStmt * then, Type type, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), then(then), type(type) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         SuspendStmt * clone() const override { return new SuspendStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Wait for concurrency statement `when (...) waitfor (... , ...) ... timeout(...) ... else ...`
+// Waitfor statement: when (...) waitfor (... , ...) ... timeout(...) ... else ...
 class WaitForStmt final : public Stmt {
 public:
+  public:
         struct Target {
                 ptr<Expr> func;
 …
         OrElse orElse;
         WaitForStmt( const CodeLocation & loc, std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        WaitForStmt( const CodeLocation & loc, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         WaitForStmt * clone() const override { return new WaitForStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Any declaration in a (compound) statement.
+// Any declaration in a (compound) statement.
 class DeclStmt final : public Stmt {
 public:
+  public:
         ptr<Decl> decl;
         DeclStmt( const CodeLocation & loc, const Decl * decl, std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), decl(decl) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+        DeclStmt( const CodeLocation & loc, const Decl * decl, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), decl(decl) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         DeclStmt * clone() const override { return new DeclStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Represents an implicit application of a constructor or destructor.
+// Represents an implicit application of a constructor or destructor.
 class ImplicitCtorDtorStmt final : public Stmt {
 public:
+  public:
         ptr<Stmt> callStmt;
         ImplicitCtorDtorStmt( const CodeLocation & loc, const Stmt * callStmt,
                 std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), callStmt(callStmt) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+                                                  std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), callStmt(callStmt) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         ImplicitCtorDtorStmt * clone() const override { return new ImplicitCtorDtorStmt{ *this }; }
         MUTATE_FRIEND
 };
 /// Mutex Statement
+// Mutex Statement
 class MutexStmt final : public Stmt {
 public:
+  public:
         ptr<Stmt> stmt;
         std::vector<ptr<Expr>> mutexObjs;
         MutexStmt( const CodeLocation & loc, const Stmt * stmt,
                 std::vector<ptr<Expr>> && mutexes, std::vector<Label> && labels = {} )
         : Stmt(loc, std::move(labels)), stmt(stmt), mutexObjs(std::move(mutexes)) {}
         const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
 private:
+                           const std::vector<ptr<Expr>> && mutexes, const std::vector<Label> && labels = {} )
+                : Stmt(loc, std::move(labels)), stmt(stmt), mutexObjs(std::move(mutexes)) {}
+        const Stmt * accept( Visitor & v ) const override { return v.visit( this ); }
+  private:
         MutexStmt * clone() const override { return new MutexStmt{ *this }; }
         MUTATE_FRIEND
 };
+}
+} // namespace ast
 #undef MUTATE_FRIEND
 // Local Variables: //
-// tab-width: 4 //
 // mode: c++ //
-// compile-command: "make install" //
 // End: //

src/AST/Visitor.hpp

-                      r97c215f
+                      rf5a51db
 // Created On       : Thr May 9 15:28:00 2019
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Fri Mar 12 18:25:07 2021
 // Update Count     : 1
+// Last Modified On : Tue Feb  1 09:09:34 2022
+// Update Count     : 2
 //
 …
     virtual const ast::Stmt *             visit( const ast::DirectiveStmt        * ) = 0;
     virtual const ast::Stmt *             visit( const ast::IfStmt               * ) = 0;
     virtual const ast::Stmt *             visit( const ast::WhileStmt            * ) = 0;
+    virtual const ast::Stmt *             visit( const ast::WhileDoStmt          * ) = 0;
     virtual const ast::Stmt *             visit( const ast::ForStmt              * ) = 0;
     virtual const ast::Stmt *             visit( const ast::SwitchStmt           * ) = 0;

src/CodeGen/CodeGenerator.cc

-                      r97c215f
+                      rf5a51db
 // Created On       : Mon May 18 07:44:20 2015
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Fri Mar 12 19:00:42 2021
 // Update Count     : 536
+// Last Modified On : Wed Feb  2 20:30:30 2022
+// Update Count     : 541
 //
 #include "CodeGenerator.h"
 …
         bool wantSpacing( Statement * stmt) {
                 return dynamic_cast< IfStmt * >( stmt ) || dynamic_cast< CompoundStmt * >( stmt ) ||
                         dynamic_cast< WhileStmt * >( stmt ) || dynamic_cast< ForStmt * >( stmt ) || dynamic_cast< SwitchStmt *>( stmt );
+                        dynamic_cast< WhileDoStmt * >( stmt ) || dynamic_cast< ForStmt * >( stmt ) || dynamic_cast< SwitchStmt *>( stmt );
+        }
 …
                 output << " ) ";
                 ifStmt->get_thenPart()->accept( *visitor );
                 if ( ifStmt->get_elsePart() != 0) {
+                ifStmt->get_then()->accept( *visitor );
+                if ( ifStmt->get_else() != 0) {
                         output << " else ";
                         ifStmt->get_elsePart()->accept( *visitor );
+                        ifStmt->get_else()->accept( *visitor );
                 } // if
+        }
 …
                         output << "fallthru";
                         break;
+                  default: ;                                                                    // prevent warning
                 } // switch
                 // print branch target for labelled break/continue/fallthru in debug mode
 …
+        }
         void CodeGenerator::postvisit( WhileStmt * whileStmt ) {
                 if ( whileStmt->get_isDoWhile() ) {
+        void CodeGenerator::postvisit( WhileDoStmt * whileDoStmt ) {
+                if ( whileDoStmt->get_isDoWhile() ) {
                         output << "do";
                 } else {
                         output << "while (";
                         whileStmt->get_condition()->accept( *visitor );
+                        whileDoStmt->get_condition()->accept( *visitor );
                         output << ")";
                 } // if
                 output << " ";
                 output << CodeGenerator::printLabels( whileStmt->get_body()->get_labels() );
                 whileStmt->get_body()->accept( *visitor );
+                output << CodeGenerator::printLabels( whileDoStmt->get_body()->get_labels() );
+                whileDoStmt->get_body()->accept( *visitor );
                 output << indent;
                 if ( whileStmt->get_isDoWhile() ) {
+                if ( whileDoStmt->get_isDoWhile() ) {
                         output << " while (";
                         whileStmt->get_condition()->accept( *visitor );
+                        whileDoStmt->get_condition()->accept( *visitor );
                         output << ");";
                 } // if

src/CodeGen/CodeGenerator.h

-                      r97c215f
+                      rf5a51db
 // Created On       : Mon May 18 07:44:20 2015
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Fri Mar 12 18:35:38 2021
 // Update Count     : 63
+// Last Modified On : Tue Feb  1 09:23:21 2022
+// Update Count     : 64
 //
 …
                 void postvisit( WaitForStmt * );
                 void postvisit( WithStmt * );
                 void postvisit( WhileStmt * );
+                void postvisit( WhileDoStmt * );
                 void postvisit( ForStmt * );
                 void postvisit( NullStmt * );

src/Common/CodeLocationTools.cpp

-                      r97c215f
+                      rf5a51db
 // Created On       : Fri Dec  4 15:42:00 2020
 // Last Modified By : Peter A. Buhr
 // Last Modified On : Fri Mar 12 18:35:37 2021
 // Update Count     : 2
+// Last Modified On : Tue Feb  1 09:14:39 2022
+// Update Count     : 3
 //
 …
     macro(DirectiveStmt, Stmt) \
     macro(IfStmt, Stmt) \
     macro(WhileStmt, Stmt) \
+    macro(WhileDoStmt, Stmt) \
     macro(ForStmt, Stmt) \
     macro(SwitchStmt, Stmt) \

src/Common/PassVisitor.h

-                      r97c215f
+                      rf5a51db
         virtual void visit( IfStmt * ifStmt ) override final;
         virtual void visit( const IfStmt * ifStmt ) override final;
         virtual void visit( WhileStmt * whileStmt ) override final;
         virtual void visit( const WhileStmt * whileStmt ) override final;
+        virtual void visit( WhileDoStmt * whileDoStmt ) override final;
+        virtual void visit( const WhileDoStmt * whileDoStmt ) override final;
         virtual void visit( ForStmt * forStmt ) override final;
         virtual void visit( const ForStmt * forStmt ) override final;
 …
         virtual Statement * mutate( DirectiveStmt * dirStmt ) override final;
         virtual Statement * mutate( IfStmt * ifStmt ) override final;
         virtual Statement * mutate( WhileStmt * whileStmt ) override final;
+        virtual Statement * mutate( WhileDoStmt * whileDoStmt ) override final;
         virtual Statement * mutate( ForStmt * forStmt ) override final;
         virtual Statement * mutate( SwitchStmt * switchStmt ) override final;

src/Common/PassVisitor.impl.h

-                      r97c215f
+                      rf5a51db
                 maybeAccept_impl( node->initialization, *this );
                 visitExpression ( node->condition );
                 node->thenPart = visitStatement( node->thenPart );
                 node->elsePart = visitStatement( node->elsePart );
+                node->then = visitStatement( node->then );
+                node->else_ = visitStatement( node->else_ );
+        }
         VISIT_END( node );
 …
                 maybeAccept_impl( node->initialization, *this );
                 visitExpression ( node->condition );
                 visitStatement  ( node->thenPart );
                 visitStatement  ( node->elsePart );
+                visitStatement  ( node->then );
+                visitStatement  ( node->else_ );
+        }
         VISIT_END( node );
 …
                 maybeMutate_impl( node->initialization, *this );
                 node->condition = mutateExpression( node->condition );
                 node->thenPart  = mutateStatement ( node->thenPart  );
                 node->elsePart  = mutateStatement ( node->elsePart  );
+                node->then  = mutateStatement ( node->then  );
+                node->else_  = mutateStatement ( node->else_  );
+        }
         MUTATE_END( Statement, node );
 …
 //--------------------------------------------------------------------------
 // WhileStmt
 template< typename pass_type >
 void PassVisitor< pass_type >::visit( WhileStmt * node ) {
+// WhileDoStmt
+template< typename pass_type >
+void PassVisitor< pass_type >::visit( WhileDoStmt * node ) {
         VISIT_START( node );
 …
 template< typename pass_type >
 void PassVisitor< pass_type >::visit( const WhileStmt * node ) {
+void PassVisitor< pass_type >::visit( const WhileDoStmt * node ) {
         VISIT_START( node );
 …
 template< typename pass_type >
 Statement * PassVisitor< pass_type >::mutate( WhileStmt * node ) {
+Statement * PassVisitor< pass_type >::mutate( WhileDoStmt * node ) {
         MUTATE_START( node );

src/Common/utility.h

-                      r97c215f
+                      rf5a51db
+}
+template< typename T >
+struct enumerate_t {
+        template<typename val_t>
+        struct value_t {
+                val_t & val;
+                size_t idx;
+        };
+        template< typename iter_t, typename val_t >
+        struct iterator_t {
+                iter_t it;
+                size_t idx;
+                iterator_t( iter_t _it, size_t _idx ) : it(_it), idx(_idx) {}
+                value_t<val_t> operator*() const { return value_t<val_t>{ *it, idx }; }
+                bool operator==(const iterator_t & o) const { return o.it == it; }
+                bool operator!=(const iterator_t & o) const { return o.it != it; }
+                iterator_t & operator++() {
+                        it++;
+                        idx++;
+                        return *this;
+                }
+                using difference_type   = typename std::iterator_traits< iter_t >::difference_type;
+                using value_type        = value_t<val_t>;
+                using pointer           = value_t<val_t> *;
+                using reference         = value_t<val_t> &;
+                using iterator_category = std::forward_iterator_tag;
+        };
+        T & ref;
+        using iterator = iterator_t< typename T::iterator, typename T::value_type >;
+        using const_iterator = iterator_t< typename T::const_iterator, const typename T::value_type >;
+        iterator begin() { return iterator( ref.begin(), 0 ); }
+        iterator end()   { return iterator( ref.end(), ref.size() ); }
+        const_iterator begin() const { return const_iterator( ref.cbegin(), 0 ); }
+        const_iterator end()   const { return const_iterator( ref.cend(), ref.size() ); }
+        const_iterator cbegin() const { return const_iterator( ref.cbegin(), 0 ); }
+        const_iterator cend()   const { return const_iterator( ref.cend(), ref.size() ); }
+};
+template< typename T >
+enumerate_t<T> enumerate( T & ref ) {
+        return enumerate_t< T >{ ref };
+}
+template< typename T >
+const enumerate_t< const T > enumerate( const T & ref ) {
+        return enumerate_t< const T >{ ref };
+}
 template< typename OutType, typename Range, typename Functor >
 OutType map_range( const Range& range, Functor&& functor ) {

src/ControlStruct/ExceptTranslate.h

r97c215f	rf5a51db
31	31
32	32	void translateTries( std::list< Declaration *> & translationUnit );
	33	void translateTries( ast::TranslationUnit & transUnit );
33	34	/* Replaces all try blocks (and their many clauses) with function definitions and calls.
34	35	* This uses the exception built-ins to produce typed output and should take place after

src/ControlStruct/ExceptTranslateNew.cpp

-                      r97c215f
+                      rf5a51db
 // Author           : Andrew Beach
 // Created On       : Mon Nov  8 11:53:00 2021
 // Last Modified By : Andrew Beach
 // Last Modified On : Mon Nov  8 16:50:00 2021
 // Update Count     : 0
+// Last Modified By : Peter A. Buhr
+// Last Modified On : Mon Jan 31 18:49:58 2022
+// Update Count     : 1
 //
 …
 #include "AST/Stmt.hpp"
 #include "AST/TranslationUnit.hpp"
+#include "AST/DeclReplacer.hpp"
 namespace ControlStruct {
 namespace {
+        typedef std::list<ast::CatchStmt*> CatchList;
+        void split( CatchList& allHandlers, CatchList& terHandlers,
+                                CatchList& resHandlers ) {
+                while ( !allHandlers.empty() ) {
+                        ast::CatchStmt * stmt = allHandlers.front();
+                        allHandlers.pop_front();
+                        if (stmt->kind == ast::ExceptionKind::Terminate) {
+                                terHandlers.push_back(stmt);
+                        } else {
+                                resHandlers.push_back(stmt);
+                        }
+                }
+        }
+        void appendDeclStmt( ast::CompoundStmt * block, ast::DeclWithType * item ) {
+                block->push_back(new ast::DeclStmt(block->location, item));
+        }
 class TranslateThrowsCore : public ast::WithGuards {
 …
+}
+class TryMutatorCore {
+        // The built in types used in translation.
+        const ast::StructDecl * except_decl;
+        const ast::StructDecl * node_decl;
+        const ast::StructDecl * hook_decl;
+        // The many helper functions for code/syntree generation.
+        ast::CompoundStmt * take_try_block( ast::TryStmt * tryStmt );
+        ast::FunctionDecl * create_try_wrapper( const ast::CompoundStmt * body );
+        ast::FunctionDecl * create_terminate_catch( CatchList &handlers );
+        ast::CompoundStmt * create_single_matcher(
+                const ast::DeclWithType * except_obj, ast::CatchStmt * modded_handler );
+        ast::FunctionDecl * create_terminate_match( CatchList &handlers );
+        ast::CompoundStmt * create_terminate_caller( CodeLocation loc, ast::FunctionDecl * try_wrapper,
+                ast::FunctionDecl * terminate_catch, ast::FunctionDecl * terminate_match );
+        ast::FunctionDecl * create_resume_handler( CatchList &handlers );
+        ast::CompoundStmt * create_resume_wrapper(
+                const ast::Stmt * wraps, const ast::FunctionDecl * resume_handler );
+        ast::FunctionDecl * create_finally_wrapper( ast::TryStmt * tryStmt );
+        ast::ObjectDecl * create_finally_hook( ast::FunctionDecl * finally_wrapper );
+        ast::Stmt * create_resume_rethrow( const ast::ThrowStmt * throwStmt );
+        // Types used in translation, make sure to use clone.
+        // void (*function)();
+        ast::FunctionDecl * try_func_t;
+        // void (*function)(int, exception);
+        ast::FunctionDecl * catch_func_t;
+        // int (*function)(exception);
+        ast::FunctionDecl * match_func_t;
+        // bool (*function)(exception);
+        ast::FunctionDecl * handle_func_t;
+        // void (*function)(__attribute__((unused)) void *);
+        ast::FunctionDecl * finally_func_t;
+        ast::StructInstType * create_except_type() {
+                assert( except_decl );
+                return new ast::StructInstType( except_decl );
+        }
+        void init_func_types();
+public:
+        TryMutatorCore() :
+                except_decl( nullptr ), node_decl( nullptr ), hook_decl( nullptr )
+        {}
+        void previsit( const ast::StructDecl *structDecl );
+        ast::Stmt * postvisit( const ast::TryStmt *tryStmt );
+        ast::Stmt * postvisit( const ast::ThrowStmt *throwStmt );
+};
+void TryMutatorCore::init_func_types() {
+        assert( except_decl );
+        ast::ObjectDecl index_obj(
+                {},
+                "__handler_index",
+                new ast::BasicType(ast::BasicType::SignedInt)
+                );
+        ast::ObjectDecl exception_obj(
+                {},
+                "__exception_inst",
+                new ast::PointerType(
+                        new ast::StructInstType( except_decl )
+                        ),
+                NULL
+                );
+        ast::ObjectDecl bool_obj(
+                {},
+                "__ret_bool",
+                new ast::BasicType( ast::BasicType::Bool ),
+                nullptr, //init
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall,
+                nullptr, //width
+                std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) }
+                );
+        ast::ObjectDecl voidptr_obj(
+                {},
+                "__hook",
+                new ast::PointerType(
+                        new ast::VoidType()
+                ),
+                nullptr, //init
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall,
+                nullptr, //width
+                std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) }
+                );
+        ast::ObjectDecl unused_index_obj(
+                {},
+                "__handler_index",
+                new ast::BasicType(ast::BasicType::SignedInt),
+                nullptr,
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall,
+                nullptr, //width
+                std::vector<ast::ptr<ast::Attribute>>{ new ast::Attribute( "unused" ) }
+        );
+        //unused_index_obj->attributes.push_back( new Attribute( "unused" ) );
+        try_func_t = new ast::FunctionDecl(
+                {},
+                "try",
+                {}, //forall
+                {}, //no param
+                {}, //no return
+                nullptr,
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall
+        );
+        catch_func_t = new ast::FunctionDecl(
+                {},
+                "catch",
+                {}, //forall
+                {ast::deepCopy(&index_obj), ast::deepCopy(&exception_obj)},//param
+                {}, //return void
+                nullptr,
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall
+        );
+        match_func_t = new ast::FunctionDecl(
+                {},
+                "match",
+                {}, //forall
+                {ast::deepCopy(&exception_obj)},
+                {ast::deepCopy(&unused_index_obj)},
+                nullptr,
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall
+        );
+        handle_func_t = new ast::FunctionDecl(
+                {},
+                "handle",
+                {}, //forall
+                {ast::deepCopy(&exception_obj)},
+                {ast::deepCopy(&bool_obj)},
+                nullptr,
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall
+        );
+        finally_func_t = new ast::FunctionDecl(
+                {},
+                "finally",
+                {}, //forall
+                {ast::deepCopy(&voidptr_obj)},
+                {}, //return void
+                nullptr,
+                ast::Storage::Classes{},
+                ast::Linkage::Cforall
+        );
+        //catch_func_t.get_parameters().push_back( index_obj.clone() );
+        //catch_func_t.get_parameters().push_back( exception_obj.clone() );
+        //match_func_t.get_returnVals().push_back( unused_index_obj );
+        //match_func_t.get_parameters().push_back( exception_obj.clone() );
+        //handle_func_t.get_returnVals().push_back( bool_obj.clone() );
+        //handle_func_t.get_parameters().push_back( exception_obj.clone() );
+        //finally_func_t.get_parameters().push_back( voidptr_obj.clone() );
+}
+// TryStmt Mutation Helpers
+/*
+ast::CompoundStmt * TryMutatorCore::take_try_block( ast::TryStmt *tryStmt ) {
+        ast::CompoundStmt * block = tryStmt->body;
+        tryStmt->body = nullptr;
+        return block;
+}
+*/
+ast::FunctionDecl * TryMutatorCore::create_try_wrapper(
+                const ast::CompoundStmt *body ) {
+        ast::FunctionDecl * ret = ast::deepCopy(try_func_t);
+        ret->stmts = body;
+        return ret;
+}
+ast::FunctionDecl * TryMutatorCore::create_terminate_catch(
+                CatchList &handlers ) {
+        std::vector<ast::ptr<ast::Stmt>> handler_wrappers;
+        assert (!handlers.empty());
+        const CodeLocation loc = handlers.front()->location;
+        ast::FunctionDecl * func_t = ast::deepCopy(catch_func_t);
+        const ast::DeclWithType * index_obj = func_t->params.front();
+        const ast::DeclWithType * except_obj = func_t->params.back();
+        // Index 1..{number of handlers}
+        int index = 0;
+        CatchList::iterator it = handlers.begin();
+        for ( ; it != handlers.end() ; ++it ) {
+                ++index;
+                ast::CatchStmt * handler = *it;
+                const CodeLocation loc = handler->location;
+                // case `index`:
+                // {
+                //     `handler.decl` = { (virtual `decl.type`)`except` };
+                //     `handler.body`;
+                // }
+                // return;
+                ast::CompoundStmt * block = new ast::CompoundStmt(loc);
+                // Just copy the exception value. (Post Validation)
+                const ast::ObjectDecl * handler_decl =
+                        handler->decl.strict_as<ast::ObjectDecl>();
+                ast::ObjectDecl * local_except = ast::deepCopy(handler_decl);
+                ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc,
+                        new ast::VariableExpr( loc, except_obj ),
+                        local_except->get_type()
+                        );
+                vcex->location = handler->location;
+                local_except->init = new ast::ListInit(loc, { new ast::SingleInit( loc, vcex ) });
+                block->push_back( new ast::DeclStmt( loc, local_except ) );
+                // Add the cleanup attribute.
+                local_except->attributes.push_back( new ast::Attribute(
+                        "cleanup",
+                        { new ast::NameExpr( loc, "__cfaehm_cleanup_terminate" ) }
+                        ) );
+                ast::DeclReplacer::DeclMap mapping;
+                mapping[handler_decl] = local_except;
+                const ast::Stmt * mutBody = strict_dynamic_cast<const ast::Stmt *>(
+                        ast::DeclReplacer::replace(handler->body, mapping));
+                block->push_back( mutBody );
+                // handler->body = nullptr;
+                handler_wrappers.push_back( new ast::CaseStmt(loc,
+                        ast::ConstantExpr::from_int(loc, index) ,
+                        { block, new ast::ReturnStmt( loc, nullptr ) }
+                        ));
+        }
+        // TODO: Some sort of meaningful error on default perhaps?
+        /*
+        std::list<Statement*> stmt_handlers;
+        while ( !handler_wrappers.empty() ) {
+                stmt_handlers.push_back( handler_wrappers.front() );
+                handler_wrappers.pop_front();
+        }
+        */
+        ast::SwitchStmt * handler_lookup = new ast::SwitchStmt(loc,
+                new ast::VariableExpr( loc, index_obj ),
+                std::move(handler_wrappers)
+                );
+        ast::CompoundStmt * body = new ast::CompoundStmt(loc,
+                {handler_lookup});
+        func_t->stmts = body;
+        return func_t;
+}
+// Create a single check from a moddified handler.
+// except_obj is referenced, modded_handler will be freed.
+ast::CompoundStmt * TryMutatorCore::create_single_matcher(
+                const ast::DeclWithType * except_obj, ast::CatchStmt * modded_handler ) {
+        // {
+        //     `modded_handler.decl`
+        //     if ( `decl.name = (virtual `decl.type`)`except`
+        //             [&& `modded_handler.cond`] ) {
+        //         `modded_handler.body`
+        //     }
+        // }
+        const CodeLocation loc = modded_handler->location;
+        ast::CompoundStmt * block = new ast::CompoundStmt(loc);
+        // Local Declaration
+        const ast::ObjectDecl * local_except =
+                modded_handler->decl.strict_as<ast::ObjectDecl>();
+        block->push_back( new ast::DeclStmt( loc,  local_except ) );
+        // Check for type match.
+        ast::VirtualCastExpr * vcex = new ast::VirtualCastExpr(loc,
+                new ast::VariableExpr(loc, except_obj ),
+                local_except->get_type()
+                );
+        ast::Expr * cond = ast::UntypedExpr::createAssign(loc,
+                new ast::VariableExpr(loc, local_except ), vcex );
+        // Add the check on the conditional if it is provided.
+        if ( modded_handler->cond ) {
+                cond = new ast::LogicalExpr( loc, cond, modded_handler->cond, ast::LogicalFlag::AndExpr );
+        }
+        // Construct the match condition.
+        block->push_back( new ast::IfStmt(loc,
+                cond, modded_handler->body, nullptr ) );
+        // xxx - how does this work in new ast
+        //modded_handler->set_decl( nullptr );
+        //modded_handler->set_cond( nullptr );
+        //modded_handler->set_body( nullptr );
+        //delete modded_handler;
+        return block;
+}
+ast::FunctionDecl * TryMutatorCore::create_terminate_match(
+                CatchList &handlers ) {
+        // int match(exception * except) {
+        //     HANDLER WRAPPERS { return `index`; }
+        // }
+        assert (!handlers.empty());
+        const CodeLocation loc = handlers.front()->location;
+        ast::CompoundStmt * body = new ast::CompoundStmt(loc);
+        ast::FunctionDecl * func_t = ast::deepCopy(match_func_t);
+        const ast::DeclWithType * except_obj = func_t->params.back();
+        // Index 1..{number of handlers}
+        int index = 0;
+        CatchList::iterator it;
+        for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
+                ++index;
+                ast::CatchStmt * handler = *it;
+                // Body should have been taken by create_terminate_catch.
+                // xxx - just ignore it?
+                // assert( nullptr == handler->get_body() );
+                // Create new body.
+                handler->body = new ast::ReturnStmt( handler->location,
+                        ast::ConstantExpr::from_int( handler->location, index ) );
+                // Create the handler.
+                body->push_back( create_single_matcher( except_obj, handler ) );
+                *it = nullptr;
+        }
+        body->push_back( new ast::ReturnStmt(loc,
+                ast::ConstantExpr::from_int( loc, 0 ) ));
+        func_t->stmts = body;
+        return func_t;
+}
+ast::CompoundStmt * TryMutatorCore::create_terminate_caller(
+                CodeLocation loc,
+                ast::FunctionDecl * try_wrapper,
+                ast::FunctionDecl * terminate_catch,
+                ast::FunctionDecl * terminate_match ) {
+        // { __cfaehm_try_terminate(`try`, `catch`, `match`); }
+        ast::UntypedExpr * caller = new ast::UntypedExpr(loc, new ast::NameExpr(loc,
+                "__cfaehm_try_terminate" ) );
+        caller->args.push_back( new ast::VariableExpr(loc, try_wrapper ) );
+        caller->args.push_back( new ast::VariableExpr(loc, terminate_catch ) );
+        caller->args.push_back( new ast::VariableExpr(loc, terminate_match ) );
+        ast::CompoundStmt * callStmt = new ast::CompoundStmt(loc);
+        callStmt->push_back( new ast::ExprStmt( loc, caller ) );
+        return callStmt;
+}
+ast::FunctionDecl * TryMutatorCore::create_resume_handler(
+                CatchList &handlers ) {
+        // bool handle(exception * except) {
+        //     HANDLER WRAPPERS { `hander->body`; return true; }
+        // }
+        assert (!handlers.empty());
+        const CodeLocation loc = handlers.front()->location;
+        ast::CompoundStmt * body = new ast::CompoundStmt(loc);
+        ast::FunctionDecl * func_t = ast::deepCopy(handle_func_t);
+        const ast::DeclWithType * except_obj = func_t->params.back();
+        CatchList::iterator it;
+        for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
+                ast::CatchStmt * handler = *it;
+                const CodeLocation loc = handler->location;
+                // Modifiy body.
+                ast::CompoundStmt * handling_code;
+                if (handler->body.as<ast::CompoundStmt>()) {
+                        handling_code =
+                        strict_dynamic_cast<ast::CompoundStmt*>( handler->body.get_and_mutate() );
+                } else {
+                        handling_code = new ast::CompoundStmt(loc);
+                        handling_code->push_back( handler->body );
+                }
+                handling_code->push_back( new ast::ReturnStmt(loc,
+                        ast::ConstantExpr::from_bool(loc, true ) ) );
+                handler->body = handling_code;
+                // Create the handler.
+                body->push_back( create_single_matcher( except_obj, handler ) );
+                *it = nullptr;
+        }
+        body->push_back( new ast::ReturnStmt(loc,
+                ast::ConstantExpr::from_bool(loc, false ) ) );
+        func_t->stmts = body;
+        return func_t;
+}
+ast::CompoundStmt * TryMutatorCore::create_resume_wrapper(
+                const ast::Stmt * wraps,
+                const ast::FunctionDecl * resume_handler ) {
+        const CodeLocation loc = wraps->location;
+        ast::CompoundStmt * body = new ast::CompoundStmt(loc);

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