diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 8 | ||||
| -rw-r--r-- | gcc/c-decl.c | 34 | ||||
| -rw-r--r-- | gcc/gimplify.c | 13 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/typename-vla-1.c | 17 | ||||
| -rw-r--r-- | gcc/testsuite/gnat.dg/forward_vla.adb | 20 |
6 files changed, 96 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 3292139..f9596e8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2006-10-06 Olivier Hainque <hainque@adacore.com> + + * gimplify.c (gimplify_type_sizes) [POINTER_TYPE, REFERENCE_TYPE]: + Don't recurse on the pointed-to type. + * c-decl.c (grokdeclarator) [cdk_pointer]: If we are in a NORMAL or + DECL context, attach an artificial TYPE_DECL to anonymous pointed-to + types with components of variable size. + 2006-10-06 Danny Smith <dannysmith@users.sourceforge.net> config/i386/mingw32.h (GOMP_SELF_SPECS): Add -mthreads for openmp. diff --git a/gcc/c-decl.c b/gcc/c-decl.c index fd20078..6379a1e 100644 --- a/gcc/c-decl.c +++ b/gcc/c-decl.c @@ -4471,6 +4471,40 @@ grokdeclarator (const struct c_declarator *declarator, type = c_build_qualified_type (type, type_quals); size_varies = 0; + /* When the pointed-to type involves components of variable size, + care must be taken to ensure that the size evaluation code is + emitted early enough to dominate all the possible later uses + and late enough for the variables on which it depends to have + been assigned. + + This is expected to happen automatically when the pointed-to + type has a name/declaration of it's own, but special attention + is required if the type is anonymous. + + We handle the NORMAL and FIELD contexts here by attaching an + artificial TYPE_DECL to such pointed-to type. This forces the + sizes evaluation at a safe point and ensures it is not deferred + until e.g. within a deeper conditional context. + + We expect nothing to be needed here for PARM or TYPENAME. + Pushing a TYPE_DECL at this point for TYPENAME would actually + be incorrect, as we might be in the middle of an expression + with side effects on the pointed-to type size "arguments" prior + to the pointer declaration point and the fake TYPE_DECL in the + enclosing context would force the size evaluation prior to the + side effects. */ + + if (!TYPE_NAME (type) + && (decl_context == NORMAL || decl_context == FIELD) + && variably_modified_type_p (type, NULL_TREE)) + { + tree decl = build_decl (TYPE_DECL, NULL_TREE, type); + DECL_ARTIFICIAL (decl) = 1; + pushdecl (decl); + finish_decl (decl, NULL_TREE, NULL_TREE); + TYPE_NAME (type) = decl; + } + type = build_pointer_type (type); /* Process type qualifiers (such as const or volatile) diff --git a/gcc/gimplify.c b/gcc/gimplify.c index 84c7219..faa5b48 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -6043,7 +6043,18 @@ gimplify_type_sizes (tree type, tree *list_p) case POINTER_TYPE: case REFERENCE_TYPE: - gimplify_type_sizes (TREE_TYPE (type), list_p); + /* We used to recurse on the pointed-to type here, which turned out to + be incorrect because its definition might refer to variables not + yet initialized at this point if a forward declaration is involved. + + It was actually useful for anonymous pointed-to types to ensure + that the sizes evaluation dominates every possible later use of the + values. Restricting to such types here would be safe since there + is no possible forward declaration around, but would introduce a + undesireable middle-end semantic to anonymity. We then defer to + front-ends the responsibilty of ensuring that the sizes are + evaluated both early and late enough, e.g. by attaching artifical + type declarations to the tree. */ break; default: diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4754970..43988d7 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2006-10-06 Olivier Hainque <hainque@adacore.com> + + * gcc.dg/typename-vla-1.c: New case. + * gnat.dg/forward_vla.adb: New case. + 2006-10-06 Jakub Jelinek <jakub@redhat.com> PR tree-optimization/29290 diff --git a/gcc/testsuite/gcc.dg/typename-vla-1.c b/gcc/testsuite/gcc.dg/typename-vla-1.c new file mode 100644 index 0000000..1616513 --- /dev/null +++ b/gcc/testsuite/gcc.dg/typename-vla-1.c @@ -0,0 +1,17 @@ +/* PR c/21536 */ +/* { dg-do run } */ +/* { dg-options "-O2 -Wuninitialized" } */ + +extern void abort (void); +extern void exit (int); + +int +main (void) +{ + int a = 1; + if (sizeof (*(++a, (char (*)[a])0)) != 2) + abort (); + exit (0); +} + + diff --git a/gcc/testsuite/gnat.dg/forward_vla.adb b/gcc/testsuite/gnat.dg/forward_vla.adb new file mode 100644 index 0000000..515112b --- /dev/null +++ b/gcc/testsuite/gnat.dg/forward_vla.adb @@ -0,0 +1,20 @@ +-- { dg-do compile } +-- { dg-options "-O2 -gnatp -Wuninitialized" } + +procedure Forward_Vla is + + function N return Natural is begin return 1; end; + + type Sequence; + type Sequence_Access is access all Sequence; + + Ptr : Sequence_Access := null; -- freeze access type + + Sequence_Length : Natural := N; + type Sequence is array (1 .. Sequence_Length) of Natural; + + Seq : Sequence; +begin + Seq (1) := 0; +end; + |