Changeset d56ca354
- Timestamp:
- Feb 12, 2018, 11:57:55 AM (7 years ago)
- Branches:
- ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc
- Children:
- fd062a66
- Parents:
- c40e7c5 (diff), cfe2f0a (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
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TabularUnified doc/papers/general/Makefile ¶
rc40e7c5 rd56ca354 18 18 19 19 FIGURES = ${addsuffix .tex, \ 20 Cdecl \ 20 21 } 21 22 -
TabularUnified doc/papers/general/Paper.tex ¶
rc40e7c5 rd56ca354 2 2 3 3 \usepackage{fullpage} 4 \usepackage{epic,eepic} 4 5 \usepackage{xspace,calc,comment} 5 6 \usepackage{upquote} % switch curled `'" to straight … … 36 37 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 37 38 38 \newcommand{\Textbf}[ 1]{{\color{red}\textbf{#1}}}39 \newcommand{\Textbf}[2][red]{{\color{#1}{\textbf{#2}}}} 39 40 \newcommand{\TODO}[1]{\textbf{TODO}: {\itshape #1}} % TODO included 40 41 %\newcommand{\TODO}[1]{} % TODO elided … … 101 102 \makeatother 102 103 104 \newenvironment{cquote}{% 105 \list{}{\lstset{resetmargins=true,aboveskip=0pt,belowskip=0pt}\topsep=4pt\parsep=0pt\leftmargin=\parindent\rightmargin\leftmargin}% 106 \item\relax 107 }{% 108 \endlist 109 }% cquote 110 103 111 % CFA programming language, based on ANSI C (with some gcc additions) 104 112 \lstdefinelanguage{CFA}[ANSI]{C}{ … … 226 234 int forty_two = identity( 42 ); $\C{// T is bound to int, forty\_two == 42}$ 227 235 \end{lstlisting} 228 The @identity@ function above can be applied to any complete \ emph{object type} (or @otype@).236 The @identity@ function above can be applied to any complete \newterm{object type} (or @otype@). 229 237 The type variable @T@ is transformed into a set of additional implicit parameters encoding sufficient information about @T@ to create and return a variable of that type. 230 238 The \CFA implementation passes the size and alignment of the type represented by an @otype@ parameter, as well as an assignment operator, constructor, copy constructor and destructor. 231 If this extra information is not needed, \eg for a pointer, the type parameter can be declared as a \ emph{data type} (or @dtype@).239 If this extra information is not needed, \eg for a pointer, the type parameter can be declared as a \newterm{data type} (or @dtype@). 232 240 233 241 In \CFA, the polymorphism runtime-cost is spread over each polymorphic call, due to passing more arguments to polymorphic functions; … … 235 243 A design advantage is that, unlike \CC template-functions, \CFA polymorphic-functions are compatible with C \emph{separate compilation}, preventing compilation and code bloat. 236 244 237 Since bare polymorphic-types provide a restricted set of available operations, \CFA provides a \ emph{type assertion}~\cite[pp.~37-44]{Alphard} mechanism to provide further type information, where type assertions may be variable or function declarations that depend on a polymorphic type-variable.245 Since bare polymorphic-types provide a restricted set of available operations, \CFA provides a \newterm{type assertion}~\cite[pp.~37-44]{Alphard} mechanism to provide further type information, where type assertions may be variable or function declarations that depend on a polymorphic type-variable. 238 246 For example, the function @twice@ can be defined using the \CFA syntax for operator overloading: 239 247 \begin{lstlisting} … … 302 310 \end{lstlisting} 303 311 Here, the single name @MAX@ replaces all the C type-specific names: @SHRT_MAX@, @INT_MAX@, @DBL_MAX@. 304 As well, restricted constant overloading is allowed for the values @0@ and @1@, which have special status in C, \eg the value @0@ is both an integer and a pointer literal, so its meaning depends on context.305 In addition, several operations are defined in terms values @0@ and @1@, \eg:306 \begin{lstlisting}307 int x;308 if (x) x++ $\C{// if (x != 0) x += 1;}$309 \end{lstlisting}310 Every @if@ and iteration statement in C compares the condition with @0@, and every increment and decrement operator is semantically equivalent to adding or subtracting the value @1@ and storing the result.311 Due to these rewrite rules, the values @0@ and @1@ have the types @zero_t@ and @one_t@ in \CFA, which allows overloading various operations for new types that seamlessly connect to all special @0@ and @1@ contexts.312 The types @zero_t@ and @one_t@ have special built in implicit conversions to the various integral types, and a conversion to pointer types for @0@, which allows standard C code involving @0@ and @1@ to work as normal.313 314 312 315 313 \subsection{Traits} 316 314 317 \CFA provides \ emph{traits} to name a group of type assertions, where the trait name allows specifying the same set of assertions in multiple locations, preventing repetition mistakes at each function declaration:315 \CFA provides \newterm{traits} to name a group of type assertions, where the trait name allows specifying the same set of assertions in multiple locations, preventing repetition mistakes at each function declaration: 318 316 \begin{lstlisting} 319 317 trait summable( otype T ) { … … 339 337 Given the information provided for an @otype@, variables of polymorphic type can be treated as if they were a complete type: stack-allocatable, default or copy-initialized, assigned, and deleted. 340 338 341 In summation, the \CFA type-system uses \ emph{nominal typing} for concrete types, matching with the C type-system, and \emph{structural typing} for polymorphic types.339 In summation, the \CFA type-system uses \newterm{nominal typing} for concrete types, matching with the C type-system, and \newterm{structural typing} for polymorphic types. 342 340 Hence, trait names play no part in type equivalence; 343 341 the names are simply macros for a list of polymorphic assertions, which are expanded at usage sites. … … 384 382 Furthermore, writing and using preprocessor macros can be unnatural and inflexible. 385 383 386 \CC, Java, and other languages use \ emph{generic types} to produce type-safe abstract data-types.384 \CC, Java, and other languages use \newterm{generic types} to produce type-safe abstract data-types. 387 385 \CFA also implements generic types that integrate efficiently and naturally with the existing polymorphic functions, while retaining backwards compatibility with C and providing separate compilation. 388 386 However, for known concrete parameters, the generic-type definition can be inlined, like \CC templates. … … 405 403 \end{lstlisting} 406 404 407 \CFA classifies generic types as either \ emph{concrete} or \emph{dynamic}.405 \CFA classifies generic types as either \newterm{concrete} or \newterm{dynamic}. 408 406 Concrete types have a fixed memory layout regardless of type parameters, while dynamic types vary in memory layout depending on their type parameters. 409 A type may have polymorphic parameters but still be concrete, called \ emph{dtype-static}.407 A type may have polymorphic parameters but still be concrete, called \newterm{dtype-static}. 410 408 Polymorphic pointers are an example of dtype-static types, \eg @forall(dtype T) T *@ is a polymorphic type, but for any @T@, @T *@ is a fixed-sized pointer, and therefore, can be represented by a @void *@ in code generation. 411 409 … … 444 442 Though \CFA implements concrete generic-types efficiently, it also has a fully general system for dynamic generic types. 445 443 As mentioned in Section~\ref{sec:poly-fns}, @otype@ function parameters (in fact all @sized@ polymorphic parameters) come with implicit size and alignment parameters provided by the caller. 446 Dynamic generic-types also have an \ emph{offset array} containing structure-member offsets.444 Dynamic generic-types also have an \newterm{offset array} containing structure-member offsets. 447 445 A dynamic generic-union needs no such offset array, as all members are at offset 0, but size and alignment are still necessary. 448 446 Access to members of a dynamic structure is provided at runtime via base-displacement addressing with the structure pointer and the member offset (similar to the @offsetof@ macro), moving a compile-time offset calculation to runtime. … … 457 455 For instance, modularity is generally provided in C by including an opaque forward-declaration of a structure and associated accessor and mutator functions in a header file, with the actual implementations in a separately-compiled @.c@ file. 458 456 \CFA supports this pattern for generic types, but the caller does not know the actual layout or size of the dynamic generic-type, and only holds it by a pointer. 459 The \CFA translator automatically generates \ emph{layout functions} for cases where the size, alignment, and offset array of a generic struct cannot be passed into a function from that function's caller.457 The \CFA translator automatically generates \newterm{layout functions} for cases where the size, alignment, and offset array of a generic struct cannot be passed into a function from that function's caller. 460 458 These layout functions take as arguments pointers to size and alignment variables and a caller-allocated array of member offsets, as well as the size and alignment of all @sized@ parameters to the generic structure (un@sized@ parameters are forbidden from being used in a context that affects layout). 461 459 Results of these layout functions are cached so that they are only computed once per type per function. %, as in the example below for @pair@. … … 481 479 Since @pair(T *, T * )@ is a concrete type, there are no implicit parameters passed to @lexcmp@, so the generated code is identical to a function written in standard C using @void *@, yet the \CFA version is type-checked to ensure the fields of both pairs and the arguments to the comparison function match in type. 482 480 483 Another useful pattern enabled by reused dtype-static type instantiations is zero-cost \ emph{tag-structures}.481 Another useful pattern enabled by reused dtype-static type instantiations is zero-cost \newterm{tag-structures}. 484 482 Sometimes information is only used for type-checking and can be omitted at runtime, \eg: 485 483 \begin{lstlisting} … … 537 535 The addition of multiple-return-value functions (MRVF) are useless without a syntax for accepting multiple values at the call-site. 538 536 The simplest mechanism for capturing the return values is variable assignment, allowing the values to be retrieved directly. 539 As such, \CFA allows assigning multiple values from a function into multiple variables, using a square-bracketed list of lvalue expressions (as above), called a \ emph{tuple}.540 541 However, functions also use \ emph{composition} (nested calls), with the direct consequence that MRVFs must also support composition to be orthogonal with single-returning-value functions (SRVF), \eg:537 As such, \CFA allows assigning multiple values from a function into multiple variables, using a square-bracketed list of lvalue expressions (as above), called a \newterm{tuple}. 538 539 However, functions also use \newterm{composition} (nested calls), with the direct consequence that MRVFs must also support composition to be orthogonal with single-returning-value functions (SRVF), \eg: 542 540 \begin{lstlisting} 543 541 printf( "%d %d\n", div( 13, 5 ) ); $\C{// return values seperated into arguments}$ … … 572 570 printf( "%d %d\n", qr ); 573 571 \end{lstlisting} 574 \CFA also supports \ emph{tuple indexing} to access single components of a tuple expression:572 \CFA also supports \newterm{tuple indexing} to access single components of a tuple expression: 575 573 \begin{lstlisting} 576 574 [int, int] * p = &qr; $\C{// tuple pointer}$ … … 615 613 \subsection{Tuple Assignment} 616 614 617 An assignment where the left side is a tuple type is called \ emph{tuple assignment}.618 There are two kinds of tuple assignment depending on whether the right side of the assignment operator has a tuple type or a non-tuple type, called \ emph{multiple} and \emph{mass assignment}, respectively.615 An assignment where the left side is a tuple type is called \newterm{tuple assignment}. 616 There are two kinds of tuple assignment depending on whether the right side of the assignment operator has a tuple type or a non-tuple type, called \newterm{multiple} and \newterm{mass assignment}, respectively. 619 617 %\lstDeleteShortInline@% 620 618 %\par\smallskip … … 650 648 \subsection{Member Access} 651 649 652 It is also possible to access multiple fields from a single expression using a \ emph{member-access}.650 It is also possible to access multiple fields from a single expression using a \newterm{member-access}. 653 651 The result is a single tuple-valued expression whose type is the tuple of the types of the members, \eg: 654 652 \begin{lstlisting} … … 780 778 Matching against a @ttype@ parameter consumes all remaining argument components and packages them into a tuple, binding to the resulting tuple of types. 781 779 In a given parameter list, there must be at most one @ttype@ parameter that occurs last, which matches normal variadic semantics, with a strong feeling of similarity to \CCeleven variadic templates. 782 As such, @ttype@ variables are also called \ emph{argument packs}.780 As such, @ttype@ variables are also called \newterm{argument packs}. 783 781 784 782 Like variadic templates, the main way to manipulate @ttype@ polymorphic functions is via recursion. … … 852 850 \subsection{Implementation} 853 851 854 Tuples are implemented in the \CFA translator via a transformation into \ emph{generic types}.852 Tuples are implemented in the \CFA translator via a transformation into \newterm{generic types}. 855 853 For each $N$, the first time an $N$-tuple is seen in a scope a generic type with $N$ type parameters is generated, \eg: 856 854 \begin{lstlisting} … … 903 901 Similarly, tuple member expressions are recursively expanded into a list of member access expressions. 904 902 905 Expressions that may contain side effects are made into \ emph{unique expressions} before being expanded by the flattening conversion.903 Expressions that may contain side effects are made into \newterm{unique expressions} before being expanded by the flattening conversion. 906 904 Each unique expression is assigned an identifier and is guaranteed to be executed exactly once: 907 905 \begin{lstlisting} … … 1052 1050 \label{s:WithClauseStatement} 1053 1051 1054 Grouping heterogenous data into \newterm{aggregate}s is a common programming practice, and an aggregate can be further organized into more complex structures, such as arrays and containers:1055 \begin{cfa} 1056 struct S { $\C{// aggregate}$1057 char c; $\C{// fields}$1052 Grouping heterogenous data into \newterm{aggregate}s (structure/union) is a common programming practice, and an aggregate can be further organized into more complex structures, such as arrays and containers: 1053 \begin{cfa} 1054 struct S { $\C{// aggregate}$ 1055 char c; $\C{// fields}$ 1058 1056 int i; 1059 1057 double d; … … 1061 1059 S s, as[10]; 1062 1060 \end{cfa} 1063 However, routines manipulating aggregates have repeition ofthe aggregate name to access its containing fields:1061 However, routines manipulating aggregates must repeat the aggregate name to access its containing fields: 1064 1062 \begin{cfa} 1065 1063 void f( S s ) { 1066 `s.`c; `s.`i; `s.`d; $\C{// access containing fields}$1064 `s.`c; `s.`i; `s.`d; $\C{// access containing fields}$ 1067 1065 } 1068 1066 \end{cfa} … … 1070 1068 \begin{C++} 1071 1069 class C { 1072 char c; $\C{// fields}$1070 char c; $\C{// fields}$ 1073 1071 int i; 1074 1072 double d; 1075 int mem() { $\C{// implicit "this" parameter}$1076 `this->`c; `this->`i; `this->`d; $\C{// access containing fields}$1073 int mem() { $\C{// implicit "this" parameter}$ 1074 `this->`c; `this->`i; `this->`d; $\C{// access containing fields}$ 1077 1075 } 1078 1076 } 1079 1077 \end{C++} 1080 Nesting of member routines in a \lstinline[language=C++]@class@ allows eliding \lstinline[language=C++]@this->@ because of nested lexical-scoping. 1078 Nesting of member routines in a \lstinline[language=C++]@class@ allows eliding \lstinline[language=C++]@this->@ because of lexical scoping. 1079 However, for other aggregate parameters, qualification is necessary: 1080 \begin{cfa} 1081 struct T { double m, n; }; 1082 int C::mem( T & t ) { $\C{// multiple aggregate parameters}$ 1083 c; i; d; $\C{\color{red}// this-\textgreater.c, this-\textgreater.i, this-\textgreater.d}$ 1084 `t.`m; `t.`n; $\C{// must qualify}$ 1085 } 1086 \end{cfa} 1081 1087 1082 1088 % In object-oriented programming, there is an implicit first parameter, often names @self@ or @this@, which is elided. 1083 1089 % In any programming language, some functions have a naturally close relationship with a particular data type. 1084 % Object-oriented programming allows this close relationship to be codified in the language by making such functions \ emph{class methods} of their related data type.1090 % Object-oriented programming allows this close relationship to be codified in the language by making such functions \newterm{class methods} of their related data type. 1085 1091 % Class methods have certain privileges with respect to their associated data type, notably un-prefixed access to the fields of that data type. 1086 1092 % When writing C functions in an object-oriented style, this un-prefixed access is swiftly missed, as access to fields of a @Foo* f@ requires an extra three characters @f->@ every time, which disrupts coding flow and clutters the produced code. … … 1088 1094 % \TODO{Fill out section. Be sure to mention arbitrary expressions in with-blocks, recent change driven by Thierry to prioritize field name over parameters.} 1089 1095 1090 \CFA provides a @with@ clause/statement (see Pascal~\cite[\S~4.F]{Pascal}) to elide aggregate qualification to fields by opening a scope containingfield identifiers.1091 Hence, the qualified fields become variables , and making it easier to optimizefield references in a block.1092 \begin{cfa} 1093 void f( S s ) `with( s )` { $\C{// with clause}$1094 c; i; d; $\C{\color{red}// s.c, s.i, s.d}$1096 To simplify the programmer experience, \CFA provides a @with@ clause/statement (see Pascal~\cite[\S~4.F]{Pascal}) to elide aggregate qualification to fields by opening a scope containing the field identifiers. 1097 Hence, the qualified fields become variables with the side-effect that it is easier to optimizing field references in a block. 1098 \begin{cfa} 1099 void f( S s ) `with( s )` { $\C{// with clause}$ 1100 c; i; d; $\C{\color{red}// s.c, s.i, s.d}$ 1095 1101 } 1096 1102 \end{cfa} … … 1098 1104 \begin{cfa} 1099 1105 int mem( S & this ) `with( this )` { $\C{// with clause}$ 1100 c; i; d; $\C{\color{red}// this.c, this.i, this.d}$ 1101 } 1102 \end{cfa} 1103 The key generality over the object-oriented approach is that one aggregate parameter \lstinline[language=C++]@this@ is not treated specially over other aggregate parameters: 1104 \begin{cfa} 1105 struct T { double m, n; }; 1106 c; i; d; $\C{\color{red}// this.c, this.i, this.d}$ 1107 } 1108 \end{cfa} 1109 with the generality of opening multiple aggregate-parameters: 1110 \begin{cfa} 1106 1111 int mem( S & s, T & t ) `with( s, t )` { $\C{// multiple aggregate parameters}$ 1107 c; i; d; $\C{\color{red}// s.c, s.i, s.d}$ 1108 m; n; $\C{\color{red}// t.m, t.n}$ 1109 } 1110 \end{cfa} 1111 The equivalent object-oriented style is: 1112 \begin{cfa} 1113 int S::mem( T & t ) { $\C{// multiple aggregate parameters}$ 1114 c; i; d; $\C{\color{red}// this-\textgreater.c, this-\textgreater.i, this-\textgreater.d}$ 1115 `t.`m; `t.`n; 1112 c; i; d; $\C{\color{red}// s.c, s.i, s.d}$ 1113 m; n; $\C{\color{red}// t.m, t.n}$ 1114 } 1115 \end{cfa} 1116 1117 In detail, the @with@ clause/statement has the form: 1118 \begin{cfa} 1119 $\emph{with-statement}$: 1120 'with' '(' $\emph{expression-list}$ ')' $\emph{compound-statement}$ 1121 \end{cfa} 1122 and may appear as the body of a routine or nested within a routine body. 1123 Each expression in the expression-list provides a type and object. 1124 The type must be an aggregate type. 1125 (Enumerations are already opened.) 1126 The object is the implicit qualifier for the open structure-fields. 1127 1128 All expressions in the expression list are open in ``parallel'' within the compound statement. 1129 This semantic is different from Pascal, which nests the openings. 1130 The difference between parallel and nesting occurs for fields with the same name but different type: 1131 \begin{cfa} 1132 struct S { int i; int j; double m; } s, w; 1133 struct T { int i; int k; int m } t, w; 1134 with( s, t ) { 1135 j + k; $\C{// unambiguous, s.j + t.m}$ 1136 m = 5.0; $\C{// unambiguous, t.m = 5.0}$ 1137 m = 1; $\C{// unambiguous, s.m = 1}$ 1138 int a = s.i + m; $\C{// unambiguous, a = s.i + t.i}$ 1139 int b = s.i + t.i; $\C{// unambiguous, qualification}$ 1140 sout | (double)m | endl; $\C{// unambiguous, cast}$ 1141 i; $\C{// ambiguous}$ 1142 } 1143 \end{cfa} 1144 \CFA's ability to overload variables means usages of field with the same names can be automatically disambiguated, eliminating most qualification. 1145 Qualification or a cast is used to disambiguate. 1146 A cast may be necessary to disambiguate between the overload variables in a @with@ expression: 1147 \begin{cfa} 1148 with( w ) { ... } $\C{// ambiguous, same name and no context}$ 1149 with( (S)w ) { ... } $\C{// unambiguous}$ 1150 \end{cfa} 1151 1152 \begin{cfa} 1153 struct S { int i, j; } sv; 1154 with( sv ) { 1155 S & sr = sv; 1156 with( sr ) { 1157 S * sp = &sv; 1158 with( *sp ) { 1159 i = 3; j = 4; $\C{\color{red}// sp-{\textgreater}i, sp-{\textgreater}j}$ 1160 } 1161 i = 3; j = 4; $\C{\color{red}// sr.i, sr.j}$ 1162 } 1163 i = 3; j = 4; $\C{\color{red}// sv.i, sv.j}$ 1116 1164 } 1117 1165 \end{cfa} … … 1122 1170 struct S1 { ... } s1; 1123 1171 struct S2 { ... } s2; 1124 `with( s1 )` { $\C{// with statement}$1172 `with( s1 )` { $\C{// with statement}$ 1125 1173 // access fields of s1 without qualification 1126 `with( s2 )` { $\C{// nesting}$1174 `with( s2 )` { $\C{// nesting}$ 1127 1175 // access fields of s1 and s2 without qualification 1128 1176 } … … 1134 1182 \end{cfa} 1135 1183 1136 When opening multiple structures, fields with the same name and type are ambiguous and must be fully qualified.1137 For fields with the same name but different type, context/cast can be used to disambiguate.1138 \begin{cfa}1139 struct S { int i; int j; double m; } a, c;1140 struct T { int i; int k; int m } b, c;1141 `with( a, b )` {1142 j + k; $\C{// unambiguous, unique names define unique types}$1143 i; $\C{// ambiguous, same name and type}$1144 a.i + b.i; $\C{// unambiguous, qualification defines unique names}$1145 m; $\C{// ambiguous, same name and no context to define unique type}$1146 m = 5.0; $\C{// unambiguous, same name and context defines unique type}$1147 m = 1; $\C{// unambiguous, same name and context defines unique type}$1148 }1149 `with( c )` { ... } $\C{// ambiguous, same name and no context}$1150 `with( (S)c )` { ... } $\C{// unambiguous, same name and cast defines unique type}$1151 \end{cfa}1152 1153 The components in the "with" clause1154 1155 with ( a, b, c ) { ... }1156 1157 serve 2 purposes: each component provides a type and object. The type must be a1158 structure type. Enumerations are already opened, and I think a union is opened1159 to some extent, too. (Or is that just unnamed unions?) The object is the target1160 that the naked structure-fields apply to. The components are open in "parallel"1161 at the scope of the "with" clause/statement, so opening "a" does not affect1162 opening "b", etc. This semantic is different from Pascal, which nests the1163 openings.1164 1165 Having said the above, it seems reasonable to allow a "with" component to be an1166 expression. The type is the static expression-type and the object is the result1167 of the expression. Again, the type must be an aggregate. Expressions require1168 parenthesis around the components.1169 1170 with( a, b, c ) { ... }1171 1172 Does this now make sense?1173 1174 Having written more CFA code, it is becoming clear to me that I *really* want1175 the "with" to be implemented because I hate having to type all those object1176 names for fields. It's a great way to drive people away from the language.1177 1178 1184 1179 1185 \subsection{Exception Handling ???} … … 1190 1196 \subsection{Alternative Declaration Syntax} 1191 1197 1198 \newcommand{\R}[1]{\Textbf{#1}} 1199 \newcommand{\B}[1]{{\Textbf[blue]{#1}}} 1200 \newcommand{\G}[1]{{\Textbf[OliveGreen]{#1}}} 1201 1202 C declaration syntax is notoriously confusing and error prone. 1203 For example, many C programmers are confused by a declaration as simple as: 1204 \begin{cquote} 1205 \lstDeleteShortInline@% 1206 \begin{tabular}{@{}ll@{}} 1207 \begin{cfa} 1208 int * x[5] 1209 \end{cfa} 1210 & 1211 \raisebox{-0.75\totalheight}{\input{Cdecl}} 1212 \end{tabular} 1213 \lstMakeShortInline@% 1214 \end{cquote} 1215 Is this an array of 5 pointers to integers or a pointer to an array of 5 integers? 1216 If there is any doubt, it implies productivity and safety issues even for basic programs. 1217 Another example of confusion results from the fact that a routine name and its parameters are embedded within the return type, mimicking the way the return value is used at the routine's call site. 1218 For example, a routine returning a pointer to an array of integers is defined and used in the following way: 1219 \begin{cfa} 1220 int `(*`f`())[`5`]` {...}; $\C{// definition}$ 1221 ... `(*`f`())[`3`]` += 1; $\C{// usage}$ 1222 \end{cfa} 1223 Essentially, the return type is wrapped around the routine name in successive layers (like an onion). 1224 While attempting to make the two contexts consistent is a laudable goal, it has not worked out in practice. 1225 1226 \CFA provides its own type, variable and routine declarations, using a different syntax. 1227 The new declarations place qualifiers to the left of the base type, while C declarations place qualifiers to the right of the base type. 1228 In the following example, \R{red} is the base type and \B{blue} is qualifiers. 1229 The \CFA declarations move the qualifiers to the left of the base type, \ie move the blue to the left of the red, while the qualifiers have the same meaning but are ordered left to right to specify a variable's type. 1230 \begin{cquote} 1231 \lstDeleteShortInline@% 1232 \lstset{moredelim=**[is][\color{blue}]{+}{+}} 1233 \begin{tabular}{@{}l@{\hspace{3em}}l@{}} 1234 \multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 1235 \begin{cfa} 1236 +[5] *+ `int` x1; 1237 +* [5]+ `int` x2; 1238 +[* [5] int]+ f`( int p )`; 1239 \end{cfa} 1240 & 1241 \begin{cfa} 1242 `int` +*+ x1 +[5]+; 1243 `int` +(*+x2+)[5]+; 1244 +int (*+f`( int p )`+)[5]+; 1245 \end{cfa} 1246 \end{tabular} 1247 \lstMakeShortInline@% 1248 \end{cquote} 1249 The only exception is bit field specification, which always appear to the right of the base type. 1250 % Specifically, the character @*@ is used to indicate a pointer, square brackets @[@\,@]@ are used to represent an array or function return value, and parentheses @()@ are used to indicate a routine parameter. 1251 However, unlike C, \CFA type declaration tokens are distributed across all variables in the declaration list. 1252 For instance, variables @x@ and @y@ of type pointer to integer are defined in \CFA as follows: 1253 \begin{cquote} 1254 \lstDeleteShortInline@% 1255 \begin{tabular}{@{}l@{\hspace{3em}}l@{}} 1256 \multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 1257 \begin{cfa} 1258 `*` int x, y; 1259 \end{cfa} 1260 & 1261 \begin{cfa} 1262 int `*`x, `*`y; 1263 \end{cfa} 1264 \end{tabular} 1265 \lstMakeShortInline@% 1266 \end{cquote} 1267 The downside of this semantics is the need to separate regular and pointer declarations: 1268 \begin{cquote} 1269 \lstDeleteShortInline@% 1270 \begin{tabular}{@{}l@{\hspace{3em}}l@{}} 1271 \multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 1272 \begin{cfa} 1273 `*` int x; 1274 int y; 1275 \end{cfa} 1276 & 1277 \begin{cfa} 1278 int `*`x, y; 1279 1280 \end{cfa} 1281 \end{tabular} 1282 \lstMakeShortInline@% 1283 \end{cquote} 1284 which is prescribing a safety benefit. 1285 Other examples are: 1286 \begin{cquote} 1287 \lstDeleteShortInline@% 1288 \begin{tabular}{@{}l@{\hspace{3em}}l@{\hspace{2em}}l@{}} 1289 \multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}} & \multicolumn{1}{c@{\hspace{2em}}}{\textbf{C}} \\ 1290 \begin{cfa} 1291 [ 5 ] int z; 1292 [ 5 ] * char w; 1293 * [ 5 ] double v; 1294 struct s { 1295 int f0:3; 1296 * int f1; 1297 [ 5 ] * int f2; 1298 }; 1299 \end{cfa} 1300 & 1301 \begin{cfa} 1302 int z[ 5 ]; 1303 char * w[ 5 ]; 1304 double (* v)[ 5 ]; 1305 struct s { 1306 int f0:3; 1307 int * f1; 1308 int * f2[ 5 ] 1309 }; 1310 \end{cfa} 1311 & 1312 \begin{cfa} 1313 // array of 5 integers 1314 // array of 5 pointers to char 1315 // pointer to array of 5 doubles 1316 1317 // common bit field syntax 1318 1319 1320 1321 \end{cfa} 1322 \end{tabular} 1323 \lstMakeShortInline@% 1324 \end{cquote} 1325 1326 All type qualifiers, \eg @const@, @volatile@, etc., are used in the normal way with the new declarations and also appear left to right, \eg: 1327 \begin{cquote} 1328 \lstDeleteShortInline@% 1329 \begin{tabular}{@{}l@{\hspace{1em}}l@{\hspace{1em}}l@{}} 1330 \multicolumn{1}{c@{\hspace{1em}}}{\textbf{\CFA}} & \multicolumn{1}{c@{\hspace{1em}}}{\textbf{C}} \\ 1331 \begin{cfa} 1332 const * const int x; 1333 const * [ 5 ] const int y; 1334 \end{cfa} 1335 & 1336 \begin{cfa} 1337 int const * const x; 1338 const int (* const y)[ 5 ] 1339 \end{cfa} 1340 & 1341 \begin{cfa} 1342 // const pointer to const integer 1343 // const pointer to array of 5 const integers 1344 \end{cfa} 1345 \end{tabular} 1346 \lstMakeShortInline@% 1347 \end{cquote} 1348 All declaration qualifiers, \eg @extern@, @static@, etc., are used in the normal way with the new declarations but can only appear at the start of a \CFA routine declaration,\footnote{\label{StorageClassSpecifier} 1349 The placement of a storage-class specifier other than at the beginning of the declaration specifiers in a declaration is an obsolescent feature.~\cite[\S~6.11.5(1)]{C11}} \eg: 1350 \begin{cquote} 1351 \lstDeleteShortInline@% 1352 \begin{tabular}{@{}l@{\hspace{3em}}l@{\hspace{2em}}l@{}} 1353 \multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}} & \multicolumn{1}{c@{\hspace{2em}}}{\textbf{C}} \\ 1354 \begin{cfa} 1355 extern [ 5 ] int x; 1356 static * const int y; 1357 \end{cfa} 1358 & 1359 \begin{cfa} 1360 int extern x[ 5 ]; 1361 const int static * y; 1362 \end{cfa} 1363 & 1364 \begin{cfa} 1365 // externally visible array of 5 integers 1366 // internally visible pointer to constant int 1367 \end{cfa} 1368 \end{tabular} 1369 \lstMakeShortInline@% 1370 \end{cquote} 1371 1372 The new declaration syntax can be used in other contexts where types are required, \eg casts and the pseudo-routine @sizeof@: 1373 \begin{cquote} 1374 \lstDeleteShortInline@% 1375 \begin{tabular}{@{}l@{\hspace{3em}}l@{}} 1376 \multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 1377 \begin{cfa} 1378 y = (* int)x; 1379 i = sizeof([ 5 ] * int); 1380 \end{cfa} 1381 & 1382 \begin{cfa} 1383 y = (int *)x; 1384 i = sizeof(int * [ 5 ]); 1385 \end{cfa} 1386 \end{tabular} 1387 \lstMakeShortInline@% 1388 \end{cquote} 1389 1390 Finally, new \CFA declarations may appear together with C declarations in the same program block, but cannot be mixed within a specific declaration. 1391 Therefore, a programmer has the option of either continuing to use traditional C declarations or take advantage of the new style. 1392 Clearly, both styles need to be supported for some time due to existing C-style header-files, particularly for UNIX-like systems. 1393 1192 1394 1193 1395 \subsection{References} 1194 1396 1195 All variables in C have an \emph{address}, a \emph{value}, and a \emph{type}; at the position in the program's memory denoted by the address, there exists a sequence of bits (the value), with the length and semantic meaning of this bit sequence defined by the type. 1196 The C type system does not always track the relationship between a value and its address; a value that does not have a corresponding address is called a \emph{rvalue} (for ``right-hand value''), while a value that does have an address is called a \emph{lvalue} (for ``left-hand value''); in @int x; x = 42;@ the variable expression @x@ on the left-hand-side of the assignment is a lvalue, while the constant expression @42@ on the right-hand-side of the assignment is a rvalue. 1197 Which address a value is located at is sometimes significant; the imperative programming paradigm of C relies on the mutation of values at specific addresses. 1198 Within a lexical scope, lvalue exressions can be used in either their \emph{address interpretation} to determine where a mutated value should be stored or in their \emph{value interpretation} to refer to their stored value; in @x = y;@ in @{ int x, y = 7; x = y; }@, @x@ is used in its address interpretation, while y is used in its value interpretation. 1199 Though this duality of interpretation is useful, C lacks a direct mechanism to pass lvalues between contexts, instead relying on \emph{pointer types} to serve a similar purpose. 1200 In C, for any type @T@ there is a pointer type @T*@, the value of which is the address of a value of type @T@; a pointer rvalue can be explicitly \emph{dereferenced} to the pointed-to lvalue with the dereference operator @*?@, while the rvalue representing the address of a lvalue can be obtained with the address-of operator @&?@. 1397 All variables in C have an \newterm{address}, a \newterm{value}, and a \newterm{type}; 1398 at the position in the program's memory denoted by the address, there exists a sequence of bits (the value), with the length and semantic meaning of this bit sequence defined by the type. 1399 The C type-system does not always track the relationship between a value and its address; 1400 a value that does not have a corresponding address is called a \newterm{rvalue} (for ``right-hand value''), while a value that does have an address is called a \newterm{lvalue} (for ``left-hand value''). 1401 For example, in @int x; x = 42;@ the variable expression @x@ on the left-hand-side of the assignment is a lvalue, while the constant expression @42@ on the right-hand-side of the assignment is a rvalue. 1402 Despite the nomenclature of ``left-hand'' and ``right-hand'', an expression's classification as lvalue or rvalue is entirely dependent on whether it has an address or not; in imperative programming, the address of a value is used for both reading and writing (mutating) a value, and as such lvalues can be converted to rvalues and read from, but rvalues cannot be mutated because they lack a location to store the updated value. 1403 1404 Within a lexical scope, lvalue expressions have an \newterm{address interpretation} for writing a value or a \newterm{value interpretation} to read a value. 1405 For example, in @x = y@, @x@ has an address interpretation, while @y@ has a value interpretation. 1406 Though this duality of interpretation is useful, C lacks a direct mechanism to pass lvalues between contexts, instead relying on \newterm{pointer types} to serve a similar purpose. 1407 In C, for any type @T@ there is a pointer type @T *@, the value of which is the address of a value of type @T@. 1408 A pointer rvalue can be explicitly \newterm{dereferenced} to the pointed-to lvalue with the dereference operator @*?@, while the rvalue representing the address of a lvalue can be obtained with the address-of operator @&?@. 1201 1409 1202 1410 \begin{cfa} 1203 1411 int x = 1, y = 2, * p1, * p2, ** p3; 1204 p1 = &x; 1205 p2 = &y; 1206 p3 = &p1; 1412 p1 = &x; $\C{// p1 points to x}$ 1413 p2 = &y; $\C{// p2 points to y}$ 1414 p3 = &p1; $\C{// p3 points to p1}$ 1207 1415 *p2 = ((*p1 + *p2) * (**p3 - *p1)) / (**p3 - 15); 1208 1416 \end{cfa} … … 1210 1418 Unfortunately, the dereference and address-of operators introduce a great deal of syntactic noise when dealing with pointed-to values rather than pointers, as well as the potential for subtle bugs. 1211 1419 For both brevity and clarity, it would be desirable to have the compiler figure out how to elide the dereference operators in a complex expression such as the assignment to @*p2@ above. 1212 However, since C defines a number of forms of \ emph{pointer arithmetic}, two similar expressions involving pointers to arithmetic types (\eg @*p1 + x@ and @p1 + x@) may each have well-defined but distinct semantics, introducing the possibility that a user programmer may write one when they mean the other, and precluding any simple algorithm for elision of dereference operators.1420 However, since C defines a number of forms of \newterm{pointer arithmetic}, two similar expressions involving pointers to arithmetic types (\eg @*p1 + x@ and @p1 + x@) may each have well-defined but distinct semantics, introducing the possibility that a user programmer may write one when they mean the other, and precluding any simple algorithm for elision of dereference operators. 1213 1421 To solve these problems, \CFA introduces reference types @T&@; a @T&@ has exactly the same value as a @T*@, but where the @T*@ takes the address interpretation by default, a @T&@ takes the value interpretation by default, as below: 1214 1422 1215 1423 \begin{cfa} 1216 in xx = 1, y = 2, & r1, & r2, && r3;1424 int x = 1, y = 2, & r1, & r2, && r3; 1217 1425 &r1 = &x; $\C{// r1 points to x}$ 1218 1426 &r2 = &y; $\C{// r2 points to y}$ … … 1236 1444 This allows \CFA references to be default-initialized (\eg to a null pointer), and also to point to different addresses throughout their lifetime. 1237 1445 This rebinding is accomplished without adding any new syntax to \CFA, but simply by extending the existing semantics of the address-of operator in C. 1446 1238 1447 In C, the address of a lvalue is always a rvalue, as in general that address is not stored anywhere in memory, and does not itself have an address. 1239 1448 In \CFA, the address of a @T&@ is a lvalue @T*@, as the address of the underlying @T@ is stored in the reference, and can thus be mutated there. … … 1249 1458 if @L@ is an lvalue of type {@T &@$_1 \cdots$@ &@$_l$} where $l \ge 0$ references (@&@ symbols) then @&L@ has type {@T `*`&@$_{\color{red}1} \cdots$@ &@$_{\color{red}l}$}, \\ \ie @T@ pointer with $l$ references (@&@ symbols). 1250 1459 \end{itemize} 1251 1252 1460 Since pointers and references share the same internal representation, code using either is equally performant; in fact the \CFA compiler converts references to pointers internally, and the choice between them in user code can be made based solely on convenience. 1253 By analogy to pointers, \CFA references also allow cv-qualifiers: 1461 1462 By analogy to pointers, \CFA references also allow cv-qualifiers such as @const@: 1254 1463 1255 1464 \begin{cfa} … … 1269 1478 1270 1479 More generally, this initialization of references from lvalues rather than pointers is an instance of a ``lvalue-to-reference'' conversion rather than an elision of the address-of operator; this conversion can actually be used in any context in \CFA an implicit conversion would be allowed. 1271 Similarly, use of a the value pointed to by a reference in an rvalue context can be thought of as a ``reference-to-rvalue'' conversion, and \CFA also includes a qualifier-adding ``reference-to-reference'' conversion, anal agous to the @T *@ to @const T *@ conversion in standard C.1480 Similarly, use of a the value pointed to by a reference in an rvalue context can be thought of as a ``reference-to-rvalue'' conversion, and \CFA also includes a qualifier-adding ``reference-to-reference'' conversion, analogous to the @T *@ to @const T *@ conversion in standard C. 1272 1481 The final reference conversion included in \CFA is ``rvalue-to-reference'' conversion, implemented by means of an implicit temporary. 1273 1482 When an rvalue is used to initialize a reference, it is instead used to initialize a hidden temporary value with the same lexical scope as the reference, and the reference is initialized to the address of this temporary. 1274 1483 This allows complex values to be succinctly and efficiently passed to functions, without the syntactic overhead of explicit definition of a temporary variable or the runtime cost of pass-by-value. 1275 \CC allows a similar binding, but only for @const@ references; the more general semantics of \CFA are an attempt to avoid the \emph{const hell} problem, in which addition of a @const@ qualifier to one reference requires a cascading chain of added qualifiers. 1484 \CC allows a similar binding, but only for @const@ references; the more general semantics of \CFA are an attempt to avoid the \newterm{const hell} problem, in which addition of a @const@ qualifier to one reference requires a cascading chain of added qualifiers. 1485 1276 1486 1277 1487 \subsection{Constructors and Destructors} … … 1279 1489 One of the strengths of C is the control over memory management it gives programmers, allowing resource release to be more consistent and precisely timed than is possible with garbage-collected memory management. 1280 1490 However, this manual approach to memory management is often verbose, and it is useful to manage resources other than memory (\eg file handles) using the same mechanism as memory. 1281 \CC is well-known for an approach to manual memory management that addresses both these issues, Resource Aquisition Is Initialization (RAII), implemented by means of special \ emph{constructor} and \emph{destructor} functions; we have implemented a similar feature in \CFA.1491 \CC is well-known for an approach to manual memory management that addresses both these issues, Resource Aquisition Is Initialization (RAII), implemented by means of special \newterm{constructor} and \newterm{destructor} functions; we have implemented a similar feature in \CFA. 1282 1492 While RAII is a common feature of object-oriented programming languages, its inclusion in \CFA does not violate the design principle that \CFA retain the same procedural paradigm as C. 1283 1493 In particular, \CFA does not implement class-based encapsulation: neither the constructor nor any other function has privileged access to the implementation details of a type, except through the translation-unit-scope method of opaque structs provided by C. … … 1311 1521 \end{cfa} 1312 1522 1313 In the example above, a \ emph{default constructor} (\ie one with no parameters besides the @this@ parameter) and destructor are defined for the @Array@ struct, a dynamic array of @int@.1314 @Array@ is an example of a \ emph{managed type} in \CFA, a type with a non-trivial constructor or destructor, or with a field of a managed type.1523 In the example above, a \newterm{default constructor} (\ie one with no parameters besides the @this@ parameter) and destructor are defined for the @Array@ struct, a dynamic array of @int@. 1524 @Array@ is an example of a \newterm{managed type} in \CFA, a type with a non-trivial constructor or destructor, or with a field of a managed type. 1315 1525 As in the example, all instances of managed types are implicitly constructed upon allocation, and destructed upon deallocation; this ensures proper initialization and cleanup of resources contained in managed types, in this case the @data@ array on the heap. 1316 1526 The exact details of the placement of these implicit constructor and destructor calls are omitted here for brevity, the interested reader should consult \cite{Schluntz17}. 1317 1527 1318 1528 Constructor calls are intended to seamlessly integrate with existing C initialization syntax, providing a simple and familiar syntax to veteran C programmers and allowing constructor calls to be inserted into legacy C code with minimal code changes. 1319 As such, \CFA also provides syntax for \ emph{copy initialization} and \emph{initialization parameters}:1529 As such, \CFA also provides syntax for \newterm{copy initialization} and \newterm{initialization parameters}: 1320 1530 1321 1531 \begin{cfa} … … 1332 1542 In addition to initialization syntax, \CFA provides two ways to explicitly call constructors and destructors. 1333 1543 Explicit calls to constructors double as a placement syntax, useful for construction of member fields in user-defined constructors and reuse of large storage allocations. 1334 While the existing function-call syntax works for explicit calls to constructors and destructors, \CFA also provides a more concise \ emph{operator syntax} for both:1544 While the existing function-call syntax works for explicit calls to constructors and destructors, \CFA also provides a more concise \newterm{operator syntax} for both: 1335 1545 1336 1546 \begin{cfa} … … 1349 1559 For compatibility with C, a copy constructor from the first union member type is also defined. 1350 1560 For @struct@ types, each of the four functions are implicitly defined to call their corresponding functions on each member of the struct. 1351 To better simulate the behaviour of C initializers, a set of \ emph{field constructors} is also generated for structures.1561 To better simulate the behaviour of C initializers, a set of \newterm{field constructors} is also generated for structures. 1352 1562 A constructor is generated for each non-empty prefix of a structure's member-list which copy-constructs the members passed as parameters and default-constructs the remaining members. 1353 1563 To allow users to limit the set of constructors available for a type, when a user declares any constructor or destructor, the corresponding generated function and all field constructors for that type are hidden from expression resolution; similarly, the generated default constructor is hidden upon declaration of any constructor. … … 1355 1565 1356 1566 In rare situations user programmers may not wish to have constructors and destructors called; in these cases, \CFA provides an ``escape hatch'' to not call them. 1357 If a variable is initialized using the syntax \lstinline|S x @= {}| it will be an \ emph{unmanaged object}, and will not have constructors or destructors called.1567 If a variable is initialized using the syntax \lstinline|S x @= {}| it will be an \newterm{unmanaged object}, and will not have constructors or destructors called. 1358 1568 Any C initializer can be the right-hand side of an \lstinline|@=| initializer, \eg \lstinline|Array a @= { 0, 0x0 }|, with the usual C initialization semantics. 1359 1569 In addition to the expressive power, \lstinline|@=| provides a simple path for migrating legacy C code to \CFA, by providing a mechanism to incrementally convert initializers; the \CFA design team decided to introduce a new syntax for this escape hatch because we believe that our RAII implementation will handle the vast majority of code in a desirable way, and we wished to maintain familiar syntax for this common case. … … 1364 1574 \section{Literals} 1365 1575 1576 C already includes limited polymorphism for literals -- @0@ can be either an integer or a pointer literal, depending on context, while the syntactic forms of literals of the various integer and floating-point types are very similar, differing from each other only in suffix. 1577 In keeping with the general \CFA approach of adding features while respecting ``the C way'' of doing things, we have extended both C's polymorphic zero and typed literal syntax to interoperate with user-defined types, while maintaining a backwards-compatible semantics. 1366 1578 1367 1579 \subsection{0/1} 1368 1580 1369 \TODO{Some text already at the end of Section~\ref{sec:poly-fns}} 1370 1581 In C, @0@ has the special property that it is the only ``false'' value; by the standard, any value which compares equal to @0@ is false, while any value that compares unequal to @0@ is true. 1582 As such, an expression @x@ in any boolean context (such as the condition of an @if@ or @while@ statement, or the arguments to an @&&@, @||@, or ternary operator) can be rewritten as @x != 0@ without changing its semantics. 1583 The operator overloading feature of \CFA provides a natural means to implement this truth value comparison for arbitrary types, but the C type system is not precise enough to distinguish an equality comparison with @0@ from an equality comparison with an arbitrary integer or pointer. 1584 To provide this precision, \CFA introduces a new type @zero_t@ as type type of literal @0@ (somewhat analagous to @nullptr_t@ and @nullptr@ in \CCeleven); @zero_t@ can only take the value @0@, but has implicit conversions to the integer and pointer types so that standard C code involving @0@ continues to work properly. 1585 With this addition, the \CFA compiler rewrites @if (x)@ and similar expressions to @if ((x) != 0)@ or the appropriate analogue, and any type @T@ can be made ``truthy'' by defining an operator overload @int ?!=?(T, zero_t)@. 1586 \CC makes types truthy by adding a conversion to @bool@; prior to the addition of explicit cast operators in \CCeleven this approach had the pitfall of making truthy types transitively convertable to any numeric type; our design for \CFA avoids this issue. 1587 1588 \CFA also includes a special type for @1@, @one_t@; like @zero_t@, @one_t@ has built-in implicit conversions to the various integral types so that @1@ maintains its expected semantics in legacy code. 1589 The addition of @one_t@ allows generic algorithms to handle the unit value uniformly for types where that is meaningful. 1590 \TODO{Make this sentence true} In particular, polymorphic functions in the \CFA prelude define @++x@ and @x++@ in terms of @x += 1@, allowing users to idiomatically define all forms of increment for a type @T@ by defining the single function @T& ?+=(T&, one_t)@; analogous overloads for the decrement operators are present as well. 1371 1591 1372 1592 \subsection{Units} … … 1397 1617 \end{cfa} 1398 1618 }% 1399 1400 1619 1401 1620 \section{Evaluation} … … 1573 1792 Finally, we demonstrate that \CFA performance for some idiomatic cases is better than C and close to \CC, showing the design is practically applicable. 1574 1793 1575 There is ongoing work on a wide range of \CFA feature extensions, including reference types, arrays with size, exceptions, concurrent primitives and modules.1794 There is ongoing work on a wide range of \CFA feature extensions, including arrays with size, exceptions, concurrent primitives, modules, and user-defined conversions. 1576 1795 (While all examples in the paper compile and run, a public beta-release of \CFA will take another 8--12 months to finalize these additional extensions.) 1577 1796 In addition, there are interesting future directions for the polymorphism design. -
TabularUnified src/libcfa/Makefile.am ¶
rc40e7c5 rd56ca354 10 10 ## Author : Peter A. Buhr 11 11 ## Created On : Sun May 31 08:54:01 2015 12 ## Last Modified By : Andrew Beach13 ## Last Modified On : Wed Jul 26 14:15:00 201714 ## Update Count : 22 112 ## Last Modified By : Peter A. Buhr 13 ## Last Modified On : Fri Feb 9 15:51:24 2018 14 ## Update Count : 223 15 15 ############################################################################### 16 16 … … 92 92 libcfa_d_a_CFLAGS = -debug -O0 #No need for __CFA_DEBUG__ since we pass -debug 93 93 94 stdhdr = ${shell echo stdhdr/*}94 stdhdr = ${shell find stdhdr -type f -printf "%p "} 95 95 96 96 cfa_includedir = $(CFA_INCDIR) -
TabularUnified src/libcfa/bits/debug.c ¶
rc40e7c5 rd56ca354 11 11 // Last Modified By : 12 12 // Last Modified On : 13 // Update Count : 013 // Update Count : 1 14 14 // 15 15 … … 47 47 void __cfaabi_dbg_bits_release() __attribute__((__weak__)) {} 48 48 49 void __cfaabi_dbg_bits_print_safe ( const char fmt[], ... ) __attribute__(( format 49 void __cfaabi_dbg_bits_print_safe ( const char fmt[], ... ) __attribute__(( format(printf, 1, 2) )) { 50 50 va_list args; 51 51 … … 60 60 } 61 61 62 void __cfaabi_dbg_bits_print_nolock( const char fmt[], ... ) __attribute__(( format 62 void __cfaabi_dbg_bits_print_nolock( const char fmt[], ... ) __attribute__(( format(printf, 1, 2) )) { 63 63 va_list args; 64 64 … … 76 76 } 77 77 78 void __cfaabi_dbg_bits_print_buffer( char in_buffer[], int in_buffer_size, const char fmt[], ... ) __attribute__(( format 78 void __cfaabi_dbg_bits_print_buffer( char in_buffer[], int in_buffer_size, const char fmt[], ... ) __attribute__(( format(printf, 3, 4) )) { 79 79 va_list args; 80 80 -
TabularUnified src/libcfa/bits/debug.h ¶
rc40e7c5 rd56ca354 10 10 // Created On : Mon Nov 28 12:27:26 2016 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Sat Jul 22 10:02:24 201713 // Update Count : 112 // Last Modified On : Thu Feb 8 12:35:19 2018 13 // Update Count : 2 14 14 // 15 15 … … 41 41 extern void __cfaabi_dbg_bits_acquire(); 42 42 extern void __cfaabi_dbg_bits_release(); 43 extern void __cfaabi_dbg_bits_print_safe ( const char fmt[], ... ) __attribute__(( format 44 extern void __cfaabi_dbg_bits_print_nolock( const char fmt[], ... ) __attribute__(( format 43 extern void __cfaabi_dbg_bits_print_safe ( const char fmt[], ... ) __attribute__(( format(printf, 1, 2) )); 44 extern void __cfaabi_dbg_bits_print_nolock( const char fmt[], ... ) __attribute__(( format(printf, 1, 2) )); 45 45 extern void __cfaabi_dbg_bits_print_vararg( const char fmt[], va_list arg ); 46 extern void __cfaabi_dbg_bits_print_buffer( char buffer[], int buffer_size, const char fmt[], ... ) __attribute__(( format 46 extern void __cfaabi_dbg_bits_print_buffer( char buffer[], int buffer_size, const char fmt[], ... ) __attribute__(( format(printf, 3, 4) )); 47 47 #ifdef __cforall 48 48 } -
TabularUnified src/libcfa/bits/defs.h ¶
rc40e7c5 rd56ca354 10 10 // Created On : Thu Nov 9 13:24:10 2017 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : T ue Jan 2 09:17:06201813 // Update Count : 212 // Last Modified On : Thu Feb 8 16:22:41 2018 13 // Update Count : 8 14 14 // 15 15 … … 34 34 35 35 #ifdef __cforall 36 #ifndef __NO_ABORT_OVERLOAD 37 void abort ( const char fmt[], ... ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)); 38 #endif 36 void abort ( const char fmt[], ... ) __attribute__ (( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )); 39 37 extern "C" { 40 38 #endif 41 void abortf( const char fmt[], ... ) __attribute__ ((__nothrow__, __leaf__, __noreturn__));39 void __cabi_abort( const char fmt[], ... ) __attribute__ (( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )); 42 40 #ifdef __cforall 43 41 } -
TabularUnified src/libcfa/concurrency/coroutine.c ¶
rc40e7c5 rd56ca354 10 10 // Created On : Mon Nov 28 12:27:26 2016 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Fri Jul 21 22:34:57 201713 // Update Count : 112 // Last Modified On : Thu Feb 8 16:10:31 2018 13 // Update Count : 4 14 14 // 15 15 … … 77 77 __cfaabi_dbg_debug_do( 78 78 if ( mprotect( this.storage, pageSize, PROT_READ | PROT_WRITE ) == -1 ) { 79 abort f( "(coStack_t *)%p.^?{}() : internal error, mprotect failure, error(%d) %s.", &this, errno, strerror( errno ) );79 abort( "(coStack_t *)%p.^?{}() : internal error, mprotect failure, error(%d) %s.", &this, errno, strerror( errno ) ); 80 80 } 81 81 ); … … 99 99 // Wrapper for co 100 100 void CoroutineCtxSwitch(coroutine_desc* src, coroutine_desc* dst) { 101 // THREAD_GETMEM( This )->disableInterrupts();101 disable_interrupts(); 102 102 103 103 // set state of current coroutine to inactive … … 115 115 src->state = Active; 116 116 117 // THREAD_GETMEM( This )->enableInterrupts();117 enable_interrupts( __cfaabi_dbg_ctx ); 118 118 } //ctxSwitchDirect 119 119 … … 135 135 __cfaabi_dbg_debug_do( 136 136 if ( mprotect( storage, pageSize, PROT_NONE ) == -1 ) { 137 abort f( "(uMachContext &)%p.createContext() : internal error, mprotect failure, error(%d) %s.", this, (int)errno, strerror( (int)errno ) );137 abort( "(uMachContext &)%p.createContext() : internal error, mprotect failure, error(%d) %s.", this, (int)errno, strerror( (int)errno ) ); 138 138 } // if 139 139 ); 140 140 141 141 if ( (intptr_t)storage == 0 ) { 142 abort f( "Attempt to allocate %d bytes of storage for coroutine or task execution-state but insufficient memory available.", size );142 abort( "Attempt to allocate %zd bytes of storage for coroutine or task execution-state but insufficient memory available.", size ); 143 143 } // if 144 144 -
TabularUnified src/libcfa/concurrency/invoke.c ¶
rc40e7c5 rd56ca354 10 10 // Created On : Tue Jan 17 12:27:26 2016 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Tue Feb 6 23:00:57201813 // Update Count : 312 // Last Modified On : Fri Feb 9 16:37:42 2018 13 // Update Count : 5 14 14 // 15 15 … … 51 51 //Final suspend, should never return 52 52 __leave_coroutine(); 53 abortf( "Resumed dead coroutine" );53 __cabi_abort( "Resumed dead coroutine" ); 54 54 } 55 55 … … 81 81 //Final suspend, should never return 82 82 __leave_thread_monitor( thrd ); 83 abortf( "Resumed dead thread" );83 __cabi_abort( "Resumed dead thread" ); 84 84 } 85 85 … … 93 93 struct coStack_t* stack = &get_coroutine( this )->stack; 94 94 95 #if defined( __i386 __)95 #if defined( __i386 ) 96 96 97 97 struct FakeStack { … … 114 114 ((struct FakeStack *)(((struct machine_context_t *)stack->context)->SP))->fcw = 0x037F; //Vol. 1 8-7 115 115 116 #elif defined( __x86_64 __)116 #elif defined( __x86_64 ) 117 117 118 118 struct FakeStack { … … 150 150 fs->arg[0] = this; 151 151 fs->arg[1] = invoke; 152 152 153 #else 153 #error Only __i386__ and __x86_64__ is supported for threads in cfa154 #error uknown hardware architecture 154 155 #endif 155 156 } -
TabularUnified src/libcfa/concurrency/invoke.h ¶
rc40e7c5 rd56ca354 10 10 // Created On : Tue Jan 17 12:27:26 2016 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Tue Jan 23 14:55:46201813 // Update Count : 312 // Last Modified On : Fri Feb 9 14:41:55 2018 13 // Update Count : 6 14 14 // 15 15 … … 202 202 void CtxSwitch( void * from, void * to ) asm ("CtxSwitch"); 203 203 204 #if defined( __x86_64__ ) 204 #if defined( __i386 ) 205 #define CtxGet( ctx ) __asm__ ( \ 206 "movl %%esp,%0\n" \ 207 "movl %%ebp,%1\n" \ 208 : "=rm" (ctx.SP), "=rm" (ctx.FP) ) 209 #elif defined( __x86_64 ) 205 210 #define CtxGet( ctx ) __asm__ ( \ 206 211 "movq %%rsp,%0\n" \ 207 212 "movq %%rbp,%1\n" \ 208 : "=rm" (ctx.SP), "=rm" (ctx.FP) )209 #elif defined( __i386__ )210 #define CtxGet( ctx ) __asm__ ( \211 "movl %%esp,%0\n" \212 "movl %%ebp,%1\n" \213 213 : "=rm" (ctx.SP), "=rm" (ctx.FP) ) 214 214 #elif defined( __ARM_ARCH ) … … 217 217 "mov %1,%%r11\n" \ 218 218 : "=rm" (ctx.SP), "=rm" (ctx.FP) ) 219 #else 220 #error unknown hardware architecture 219 221 #endif 220 222 -
TabularUnified src/libcfa/concurrency/kernel.c ¶
rc40e7c5 rd56ca354 10 10 // Created On : Tue Jan 17 12:27:26 2017 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : T ue Feb 6 21:51:26201813 // Update Count : 412 // Last Modified On : Thu Feb 8 23:52:19 2018 13 // Update Count : 5 14 14 // 15 15 16 16 //C Includes 17 17 #include <stddef.h> 18 #define ftype `ftype`19 18 extern "C" { 20 19 #include <stdio.h> … … 24 23 #include <unistd.h> 25 24 } 26 #undef ftype27 25 28 26 //CFA Includes -
TabularUnified src/libcfa/concurrency/monitor.c ¶
rc40e7c5 rd56ca354 10 10 // Created On : Thd Feb 23 12:27:26 2017 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Mon Jul 31 14:59:05 201713 // Update Count : 312 // Last Modified On : Thu Feb 8 16:12:20 2018 13 // Update Count : 4 14 14 // 15 15 … … 87 87 thread_desc * thrd = this_thread; 88 88 89 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);89 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner); 90 90 91 91 if( !this->owner ) { … … 93 93 set_owner( this, thrd ); 94 94 95 __cfaabi_dbg_print_safe( "Kernel : mon is free \n");95 __cfaabi_dbg_print_safe( "Kernel : mon is free \n" ); 96 96 } 97 97 else if( this->owner == thrd) { … … 99 99 this->recursion += 1; 100 100 101 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n");101 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n" ); 102 102 } 103 103 else if( is_accepted( this, group) ) { … … 108 108 reset_mask( this ); 109 109 110 __cfaabi_dbg_print_safe( "Kernel : mon accepts \n");110 __cfaabi_dbg_print_safe( "Kernel : mon accepts \n" ); 111 111 } 112 112 else { 113 __cfaabi_dbg_print_safe( "Kernel : blocking \n");113 __cfaabi_dbg_print_safe( "Kernel : blocking \n" ); 114 114 115 115 // Some one else has the monitor, wait in line for it … … 118 118 BlockInternal( &this->lock ); 119 119 120 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);120 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this); 121 121 122 122 // BlockInternal will unlock spinlock, no need to unlock ourselves … … 124 124 } 125 125 126 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);126 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this); 127 127 128 128 // Release the lock and leave … … 136 136 thread_desc * thrd = this_thread; 137 137 138 __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);138 __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner); 139 139 140 140 141 141 if( !this->owner ) { 142 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);142 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this); 143 143 144 144 // No one has the monitor, just take it … … 151 151 // We already have the monitor... but where about to destroy it so the nesting will fail 152 152 // Abort! 153 abort f("Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.");153 abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex." ); 154 154 } 155 155 … … 158 158 __monitor_group_t group = { &this, 1, func }; 159 159 if( is_accepted( this, group) ) { 160 __cfaabi_dbg_print_safe( "Kernel : mon accepts dtor, block and signal it \n");160 __cfaabi_dbg_print_safe( "Kernel : mon accepts dtor, block and signal it \n" ); 161 161 162 162 // Wake the thread that is waiting for this … … 177 177 } 178 178 else { 179 __cfaabi_dbg_print_safe( "Kernel : blocking \n");179 __cfaabi_dbg_print_safe( "Kernel : blocking \n" ); 180 180 181 181 wait_ctx( this_thread, 0 ) … … 190 190 } 191 191 192 __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);192 __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this); 193 193 194 194 } … … 199 199 lock( this->lock __cfaabi_dbg_ctx2 ); 200 200 201 __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", this_thread, this, this->owner);201 __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", this_thread, this, this->owner); 202 202 203 203 verifyf( this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", this_thread, this->owner, this->recursion, this ); … … 209 209 // it means we don't need to do anything 210 210 if( this->recursion != 0) { 211 __cfaabi_dbg_print_safe( "Kernel : recursion still %d\n", this->recursion);211 __cfaabi_dbg_print_safe( "Kernel : recursion still %d\n", this->recursion); 212 212 unlock( this->lock ); 213 213 return; … … 228 228 __cfaabi_dbg_debug_do( 229 229 if( this_thread != this->owner ) { 230 abort f("Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, this_thread, this->owner);230 abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, this_thread, this->owner); 231 231 } 232 232 if( this->recursion != 1 ) { 233 abort f("Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);233 abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1); 234 234 } 235 235 ) … … 256 256 // If we haven't left the last level of recursion 257 257 // it must mean there is an error 258 if( this->recursion != 0) { abort f("Thread internal monitor has unbalanced recursion"); }258 if( this->recursion != 0) { abort( "Thread internal monitor has unbalanced recursion" ); } 259 259 260 260 // Fetch the next thread, can be null … … 302 302 (this_thread->monitors){m, count, func}; 303 303 304 // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);304 // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count); 305 305 306 306 // Enter the monitors in order … … 308 308 enter( group ); 309 309 310 // __cfaabi_dbg_print_safe( "MGUARD : entered\n");310 // __cfaabi_dbg_print_safe( "MGUARD : entered\n" ); 311 311 } 312 312 … … 314 314 // Dtor for monitor guard 315 315 void ^?{}( monitor_guard_t & this ) { 316 // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);316 // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count); 317 317 318 318 // Leave the monitors in order 319 319 leave( this.m, this.count ); 320 320 321 // __cfaabi_dbg_print_safe( "MGUARD : left\n");321 // __cfaabi_dbg_print_safe( "MGUARD : left\n" ); 322 322 323 323 // Restore thread context … … 427 427 thread_desc * this_thrd = this_thread; 428 428 if ( this.monitor_count != this_thrd->monitors.size ) { 429 abort f( "Signal on condition %p made with different number of monitor(s), expected %i got %i", &this, this.monitor_count, this_thrd->monitors.size );429 abort( "Signal on condition %p made with different number of monitor(s), expected %i got %i", &this, this.monitor_count, this_thrd->monitors.size ); 430 430 } 431 431 432 432 for(int i = 0; i < this.monitor_count; i++) { 433 433 if ( this.monitors[i] != this_thrd->monitors[i] ) { 434 abort f( "Signal on condition %p made with different monitor, expected %p got %i", &this, this.monitors[i], this_thrd->monitors[i] );434 abort( "Signal on condition %p made with different monitor, expected %p got %i", &this, this.monitors[i], this_thrd->monitors[i] ); 435 435 } 436 436 } … … 534 534 if(actual_count == 0) return; 535 535 536 __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );536 __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" ); 537 537 538 538 // Create storage for monitor context … … 551 551 __acceptable_t& accepted = mask[index]; 552 552 if( accepted.is_dtor ) { 553 __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );553 __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" ); 554 554 verifyf( accepted.size == 1, "ERROR: Accepted dtor has more than 1 mutex parameter." ); 555 555 … … 563 563 } 564 564 else { 565 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );565 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" ); 566 566 567 567 // Create the node specific to this wait operation … … 577 577 } 578 578 #endif 579 __cfaabi_dbg_print_buffer_local( "\n" );579 __cfaabi_dbg_print_buffer_local( "\n" ); 580 580 581 581 // Set the owners to be the next thread … … 588 588 monitor_restore; 589 589 590 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );590 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" ); 591 591 } 592 592 … … 598 598 599 599 if( duration == 0 ) { 600 __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );600 __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" ); 601 601 602 602 unlock_all( locks, count ); … … 607 607 608 608 609 verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );610 611 __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );609 verifyf( duration < 0, "Timeout on waitfor statments not supported yet." ); 610 611 __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" ); 612 612 613 613 // Create the node specific to this wait operation … … 631 631 monitor_restore; 632 632 633 __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );633 __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" ); 634 634 635 635 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted); … … 640 640 641 641 static inline void set_owner( monitor_desc * this, thread_desc * owner ) { 642 // __cfaabi_dbg_print_safe( "Kernal : Setting owner of %p to %p ( was %p)\n", this, owner, this->owner );642 // __cfaabi_dbg_print_safe( "Kernal : Setting owner of %p to %p ( was %p)\n", this, owner, this->owner ); 643 643 644 644 //Pass the monitor appropriately … … 672 672 static inline thread_desc * next_thread( monitor_desc * this ) { 673 673 //Check the signaller stack 674 __cfaabi_dbg_print_safe( "Kernel : mon %p AS-stack top %p\n", this, this->signal_stack.top);674 __cfaabi_dbg_print_safe( "Kernel : mon %p AS-stack top %p\n", this, this->signal_stack.top); 675 675 __condition_criterion_t * urgent = pop( this->signal_stack ); 676 676 if( urgent ) { … … 814 814 thread_desc * thrd = this_thread; 815 815 if( !this.monitors ) { 816 // __cfaabi_dbg_print_safe( "Branding\n");816 // __cfaabi_dbg_print_safe( "Branding\n" ); 817 817 assertf( thrd->monitors.data != NULL, "No current monitor to brand condition %p", thrd->monitors.data ); 818 818 this.monitor_count = thrd->monitors.size; -
TabularUnified src/libcfa/concurrency/preemption.c ¶
rc40e7c5 rd56ca354 10 10 // Created On : Mon Jun 5 14:20:42 2017 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Tue Feb 6 15:00:36201813 // Update Count : 1 012 // Last Modified On : Fri Feb 9 16:38:13 2018 13 // Update Count : 14 14 14 // 15 15 16 16 #include "preemption.h" 17 17 18 #define ftype `ftype`19 18 extern "C" { 20 19 #include <errno.h> … … 23 22 #include <unistd.h> 24 23 } 25 #undef ftype26 24 27 25 #include "bits/signal.h" … … 50 48 51 49 // Machine specific register name 52 #if defined(__x86_64__) 50 #if defined( __i386 ) 51 #define CFA_REG_IP gregs[REG_EIP] 52 #elif defined( __x86_64 ) 53 53 #define CFA_REG_IP gregs[REG_RIP] 54 #elif defined(__i386__) 55 #define CFA_REG_IP gregs[REG_EIP] 56 #elif defined(__ARM_ARCH__) 54 #elif defined( __ARM_ARCH ) 57 55 #define CFA_REG_IP arm_pc 56 #else 57 #error unknown hardware architecture 58 58 #endif 59 59 … … 197 197 198 198 if ( pthread_sigmask( SIG_UNBLOCK, &mask, NULL ) == -1 ) { 199 abort f( "internal error, pthread_sigmask" );199 abort( "internal error, pthread_sigmask" ); 200 200 } 201 201 } … … 208 208 209 209 if ( pthread_sigmask( SIG_BLOCK, &mask, NULL ) == -1 ) { 210 abort f( "internal error, pthread_sigmask" );210 abort( "internal error, pthread_sigmask" ); 211 211 } 212 212 } … … 247 247 // Called from kernel_startup 248 248 void kernel_start_preemption() { 249 __cfaabi_dbg_print_safe( "Kernel : Starting preemption\n");249 __cfaabi_dbg_print_safe( "Kernel : Starting preemption\n" ); 250 250 251 251 // Start with preemption disabled until ready … … 268 268 // Called from kernel_shutdown 269 269 void kernel_stop_preemption() { 270 __cfaabi_dbg_print_safe( "Kernel : Preemption stopping\n");270 __cfaabi_dbg_print_safe( "Kernel : Preemption stopping\n" ); 271 271 272 272 // Block all signals since we are already shutting down … … 284 284 // Preemption is now fully stopped 285 285 286 __cfaabi_dbg_print_safe( "Kernel : Preemption stopped\n");286 __cfaabi_dbg_print_safe( "Kernel : Preemption stopped\n" ); 287 287 } 288 288 … … 322 322 case PREEMPT_TERMINATE: verify(this_processor->do_terminate); 323 323 default: 324 abort f( "internal error, signal value is %d", sfp->si_value.sival_int );324 abort( "internal error, signal value is %d", sfp->si_value.sival_int ); 325 325 } 326 326 … … 328 328 if( !preemption_ready() ) { return; } 329 329 330 __cfaabi_dbg_print_buffer_decl( " KERNEL: preempting core %p (%p).\n", this_processor, this_thread);330 __cfaabi_dbg_print_buffer_decl( " KERNEL: preempting core %p (%p).\n", this_processor, this_thread); 331 331 332 332 preemption_in_progress = true; // Sync flag : prevent recursive calls to the signal handler … … 348 348 349 349 if ( pthread_sigmask( SIG_BLOCK, &mask, NULL ) == -1 ) { 350 abort f( "internal error, pthread_sigmask" );350 abort( "internal error, pthread_sigmask" ); 351 351 } 352 352 … … 365 365 continue; 366 366 case EINVAL : 367 abort f("Timeout was invalid.");367 abort( "Timeout was invalid." ); 368 368 default: 369 abort f("Unhandled error %d", err);369 abort( "Unhandled error %d", err); 370 370 } 371 371 } … … 374 374 assertf(sig == SIGALRM, "Kernel Internal Error, sigwait: Unexpected signal %d (%d : %d)\n", sig, info.si_code, info.si_value.sival_int); 375 375 376 // __cfaabi_dbg_print_safe( "Kernel : Caught alarm from %d with %d\n", info.si_code, info.si_value.sival_int );376 // __cfaabi_dbg_print_safe( "Kernel : Caught alarm from %d with %d\n", info.si_code, info.si_value.sival_int ); 377 377 // Switch on the code (a.k.a. the sender) to 378 378 switch( info.si_code ) … … 382 382 case SI_TIMER: 383 383 case SI_KERNEL: 384 // __cfaabi_dbg_print_safe( "Kernel : Preemption thread tick\n");384 // __cfaabi_dbg_print_safe( "Kernel : Preemption thread tick\n" ); 385 385 lock( event_kernel->lock __cfaabi_dbg_ctx2 ); 386 386 tick_preemption(); … … 396 396 397 397 EXIT: 398 __cfaabi_dbg_print_safe( "Kernel : Preemption thread stopping\n");398 __cfaabi_dbg_print_safe( "Kernel : Preemption thread stopping\n" ); 399 399 return NULL; 400 400 } -
TabularUnified src/libcfa/exception.c ¶
rc40e7c5 rd56ca354 9 9 // Author : Andrew Beach 10 10 // Created On : Mon Jun 26 15:13:00 2017 11 // Last Modified By : Andrew Beach12 // Last Modified On : Thr Aug 17 15:45:00 201713 // Update Count : 711 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Fri Feb 9 14:41:55 2018 13 // Update Count : 8 14 14 // 15 15 … … 453 453 // match, which is no way generic. Some more works need to be done if we want to have a single call to the try routine. 454 454 455 #if defined( __ x86_64__ ) || defined( __i386__)455 #if defined( __i386 ) || defined( __x86_64 ) 456 456 asm ( 457 457 //HEADER … … 476 476 // " .section .note.GNU-stack,\"x\",@progbits\n" 477 477 ); 478 #endif // __ x86_64__ || __i386__478 #endif // __i386 || __x86_64 -
TabularUnified src/libcfa/interpose.c ¶
rc40e7c5 rd56ca354 10 10 // Created On : Wed Mar 29 16:10:31 2017 11 11 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Wed Feb 7 09:05:18201813 // Update Count : 5912 // Last Modified On : Thu Feb 8 16:18:09 2018 13 // Update Count : 75 14 14 // 15 15 … … 28 28 } 29 29 30 #define __NO_ABORT_OVERLOAD // no abort overload avoid ambiguities31 30 #include "bits/debug.h" 32 31 #include "bits/defs.h" … … 51 50 error = dlerror(); 52 51 if ( error ) { 53 abort f( "interpose_symbol : failed to open libc, %s\n", error );52 abort( "interpose_symbol : failed to open libc, %s\n", error ); 54 53 } 55 54 #endif … … 69 68 70 69 error = dlerror(); 71 if ( error ) abort f( "interpose_symbol : internal error, %s\n", error );70 if ( error ) abort( "interpose_symbol : internal error, %s\n", error ); 72 71 73 72 return originalFunc.fptr; … … 98 97 99 98 struct { 100 __typeof__( exit ) exit __attribute__(( noreturn));101 __typeof__( abort ) abort __attribute__(( noreturn));99 void (* exit)( int ) __attribute__ (( __noreturn__ )); 100 void (* abort)( void ) __attribute__ (( __noreturn__ )); 102 101 } __cabi_libc; 103 102 … … 123 122 124 123 // Forward declare abort after the __typeof__ call to avoid ambiguities 125 void abort ( const char fmt[], ... ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)); 124 void exit( int status, const char fmt[], ... ) __attribute__ (( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ )); 125 void abort( const char fmt[], ... ) __attribute__ (( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )); 126 126 127 127 extern "C" { 128 void abort( void ) __attribute__ (( __nothrow__, __leaf__, __noreturn__)) {129 abort f( NULL );130 } 131 132 void abortf( const char fmt[], ... ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) {128 void abort( void ) __attribute__ (( __nothrow__, __leaf__, __noreturn__ )) { 129 abort( NULL ); 130 } 131 132 void __cabi_abort( const char fmt[], ... ) __attribute__ (( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) { 133 133 va_list argp; 134 134 va_start( argp, fmt ); … … 137 137 } 138 138 139 void exit( int __status ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) {140 __cabi_libc.exit( __status);141 } 142 } 143 144 void * kernel_abort ( void ) __attribute__ (( __nothrow__, __leaf__, __weak__)) { return NULL; }145 void kernel_abort_msg( void * data, char * buffer, int size ) __attribute__ (( __nothrow__, __leaf__, __weak__)) {}146 int kernel_abort_lastframe( void ) __attribute__ (( __nothrow__, __leaf__, __weak__)) { return 4; }139 void exit( int status ) __attribute__ (( __nothrow__, __leaf__, __noreturn__ )) { 140 __cabi_libc.exit( status ); 141 } 142 } 143 144 void * kernel_abort ( void ) __attribute__ (( __nothrow__, __leaf__, __weak__ )) { return NULL; } 145 void kernel_abort_msg( void * data, char * buffer, int size ) __attribute__ (( __nothrow__, __leaf__, __weak__ )) {} 146 int kernel_abort_lastframe( void ) __attribute__ (( __nothrow__, __leaf__, __weak__ )) { return 4; } 147 147 148 148 enum { abort_text_size = 1024 }; … … 150 150 static int abort_lastframe; 151 151 152 void abort( const char fmt[], ... ) __attribute__ ((__nothrow__, __leaf__, __noreturn__)) { 152 void exit( int status, const char fmt[], ... ) __attribute__ (( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ )) { 153 va_list args; 154 va_start( args, fmt ); 155 vfprintf( stderr, fmt, args ); 156 va_end( args ); 157 __cabi_libc.exit( status ); 158 } 159 160 void abort( const char fmt[], ... ) __attribute__ (( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )) { 153 161 void * kernel_data = kernel_abort(); // must be done here to lock down kernel 154 162 int len; … … 226 234 227 235 void sigHandler_segv( __CFA_SIGPARMS__ ) { 228 abort f( "Addressing invalid memory at location %p\n"236 abort( "Addressing invalid memory at location %p\n" 229 237 "Possible cause is reading outside the address space or writing to a protected area within the address space with an invalid pointer or subscript.\n", 230 238 sfp->si_addr ); … … 232 240 233 241 void sigHandler_ill( __CFA_SIGPARMS__ ) { 234 abort f( "Executing illegal instruction at location %p.\n"242 abort( "Executing illegal instruction at location %p.\n" 235 243 "Possible cause is stack corruption.\n", 236 244 sfp->si_addr ); … … 248 256 default: msg = "unknown"; 249 257 } // choose 250 abort f( "Computation error %s at location %p.\n", msg, sfp->si_addr );258 abort( "Computation error %s at location %p.\n", msg, sfp->si_addr ); 251 259 } 252 260 -
TabularUnified src/prelude/builtins.c ¶
rc40e7c5 rd56ca354 9 9 // Author : Peter A. Buhr 10 10 // Created On : Fri Jul 21 16:21:03 2017 11 // Last Modified By : Andrew Beach12 // Last Modified On : T us Jul 25 15:33:00 201713 // Update Count : 1 411 // Last Modified By : Peter A. Buhr 12 // Last Modified On : Thu Feb 8 12:47:59 2018 13 // Update Count : 19 14 14 // 15 15 … … 20 20 #include "../libcfa/virtual.h" 21 21 #include "../libcfa/exception.h" 22 23 void exit( int status, const char fmt[], ... ) __attribute__ (( format(printf, 2, 3), __nothrow__, __leaf__, __noreturn__ )); 24 void abort ( const char fmt[], ... ) __attribute__ (( format(printf, 1, 2), __nothrow__, __leaf__, __noreturn__ )); 22 25 23 26 // exponentiation operator implementation -
TabularUnified src/tests/preempt_longrun/Makefile.am ¶
rc40e7c5 rd56ca354 18 18 max_time=600 19 19 preempt=1_000ul 20 debug=-debug 20 21 21 22 REPEAT = ${abs_top_srcdir}/tools/repeat 22 23 TIME = /usr/bin/time -f "%E" 23 24 24 BUILD_FLAGS = -g -Wall -Wno-unused-function -quiet @CFA_FLAGS@ - debug -O2 -DPREEMPTION_RATE=${preempt}25 BUILD_FLAGS = -g -Wall -Wno-unused-function -quiet @CFA_FLAGS@ -O2 -DPREEMPTION_RATE=${preempt} 25 26 CFLAGS = ${BUILD_FLAGS} 26 27 CC = @CFA_BINDIR@/@CFA_NAME@ 27 28 28 TESTS = block c reate disjoint enter enter3 processor stack wait yield29 TESTS = block coroutine create disjoint enter enter3 processor stack wait yield 29 30 30 31 .INTERMEDIATE: ${TESTS} … … 36 37 37 38 % : %.c ${CC} 38 ${AM_V_GEN}${CC} ${CFLAGS} ${<} -o ${@}39 ${AM_V_GEN}${CC} ${CFLAGS} ${<} $(debug) -o ${@} 39 40 40 41 %.run : % ${REPEAT} -
TabularUnified src/tests/preempt_longrun/Makefile.in ¶
rc40e7c5 rd56ca354 451 451 max_time = 600 452 452 preempt = 1_000ul 453 debug = -debug 453 454 REPEAT = ${abs_top_srcdir}/tools/repeat 454 455 TIME = /usr/bin/time -f "%E" 455 BUILD_FLAGS = -g -Wall -Wno-unused-function -quiet @CFA_FLAGS@ - debug -O2 -DPREEMPTION_RATE=${preempt}456 TESTS = block c reate disjoint enter enter3 processor stack wait yield456 BUILD_FLAGS = -g -Wall -Wno-unused-function -quiet @CFA_FLAGS@ -O2 -DPREEMPTION_RATE=${preempt} 457 TESTS = block coroutine create disjoint enter enter3 processor stack wait yield 457 458 all: all-am 458 459 … … 643 644 $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \ 644 645 "$$tst" $(AM_TESTS_FD_REDIRECT) 646 coroutine.log: coroutine 647 @p='coroutine'; \ 648 b='coroutine'; \ 649 $(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \ 650 --log-file $$b.log --trs-file $$b.trs \ 651 $(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \ 652 "$$tst" $(AM_TESTS_FD_REDIRECT) 645 653 create.log: create 646 654 @p='create'; \ … … 873 881 874 882 % : %.c ${CC} 875 ${AM_V_GEN}${CC} ${CFLAGS} ${<} -o ${@}883 ${AM_V_GEN}${CC} ${CFLAGS} ${<} $(debug) -o ${@} 876 884 877 885 %.run : % ${REPEAT}
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