Changeset b81fd95 for src/SynTree

Timestamp:

Jul 29, 2020, 11:29:01 PM (4 years ago)

Author:

Michael Brooks <mlbrooks@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

0c760db

Parents:

1d17939

Message:

Fix bug where pointer and reference types allow unsound initialization and return. Fixes #189

There are two instances of the same basic change, which is using conversionCost instead of castCost for resolving...
A: an InitExpr?, always; affects variable initializations
B: a CastExpr?, for type-system-generated casts only; affects function returns

Changing the behaviour of the typechecker on initialization (do A) and cast (do B):
src/ResolvExpr/AlternativeFinder.cc
src/SynTree/Expression.h
testsinit1.*

Making type of string literal consistent with how C defines it (accommodate A):
src/Parser/ExpressionNode.cc

Making type system happy with incumbent use of void* (accommodate A):
libcfa/src/concurrency/kernel.cfa
libcfa/src/containers/list.hfa
tests/bugs/66.cfa
tests/avltree/avl1.cfa
tests/concurrent/signal/block.cfa
tests/searchsort.cfa

Making type system happy with incumbent plan-9 downcast (accommodate B):
libcfa/src/containers/list.hfa

Fixing previously incorrect constness of declarations (accommodate A):
tests/exceptions/defaults.cfa
libcfa/src/iostream.hfa

Fixing previously incorrect isGenerated classification of casts that desugaring introduces (accommodate B):
src/Concurrency/Keywords.cc
src/Concurrency/Waitfor.cc

Working around trac #207 (revealed by A):
tests/io2.cfa

Working around trac #208 (speculatively created by B):
libcfa/src/bits/locks.hfa
libcfa/src/concurrency/preemption.cfa

Misc:
tests/exceptions/conditional.cfa (accommodate A)

a _msg function for an exception was declared with wrong return type, so it was not compatible for assignment into the vtable instance

libcfa/src/stdlib.hfa

the compiler now prohibits a prior attempt to call a nonexistent realloc overload; calling alloc_align in its place

File:

• src/SynTree/Expression.h (modified) (1 diff)

src/SynTree/Expression.h

@@ -206 +206 @@
   public:
         Expression * arg;
-        bool isGenerated = true; // cast generated implicitly by code generation or explicit in program
+
+        // Inidicates cast is introduced by the CFA type system.
+        // true for casts that the resolver introduces to force a return type
+        // false for casts from user code
+        // false for casts from desugaring advanced CFA features into simpler CFA
+        // example
+        //   int * p;     // declaration
+        //   (float *) p; // use, with subject cast
+        // subject cast isGenerated means we are considering an interpretation with a type mismatch
+        // subject cast not isGenerated means someone in charge wants it that way
+        bool isGenerated = true;
 
         CastExpr( Expression * arg, bool isGenerated = true );