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| author | Roger Sayle <roger@nextmovesoftware.com> | 2021-09-01 08:38:39 +0100 |
|---|---|---|
| committer | Roger Sayle <roger@nextmovesoftware.com> | 2021-09-01 08:38:39 +0100 |
| commit | 823685221de986afb729910a6f2237f07a377f17 (patch) | |
| tree | 3397097f226bb1f8809c72f58a346beb41ffa10b /gcc/testsuite/gcc.dg | |
| parent | d2874d905647a1d146dafa60199d440e837adc4d (diff) | |
| download | gcc-823685221de986afb729910a6f2237f07a377f17.zip gcc-823685221de986afb729910a6f2237f07a377f17.tar.gz gcc-823685221de986afb729910a6f2237f07a377f17.tar.bz2 | |
C: PR c/79412: Poison decls with error_mark_node after type mismatch
This patch fixes an ICE during error-recovery regression in the C front-end.
The symptom is that the middle-end's sanity checking assertions fail during
gimplification when being asked to increment an array, which is non-sense.
The issue is that the C-front end has detected the type mismatch and
reported an error to the user, but hasn't provided any indication of this
to the middle-end, simply passing bogus trees that the optimizers recognize
as invalid.
This appears to be a frequently reported ICE with 94730, 94731, 101036
and 101365 all marked as duplicates.
I believe the correct (polite) fix is to mark the mismatched types as
problematic/dubious in the front-end, when the error is spotted, so that
the middle-end has a heads-up and can be a little more forgiving. This
patch to c-decl.c's duplicate_decls sets (both) mismatched types to
error_mark_node if they are significantly different, and we've issued
an error message. Alas, this is too punitive for FUNCTION_DECLs where
we store return types, parameter lists, parameter types and attributes
in the type, but fortunately the middle-end is already more cautious
about trusting possibly suspect function types.
This fix required one minor change to the testsuite, typedef-var-2.c
where after conflicting type definitions, we now no longer assume that
the (first or) second definition is the correct one. This change only
affects the behaviour after seen_error(), so should be relatively safe.
2021-09-01 Roger Sayle <roger@nextmovesoftware.com>
Joseph Myers <joseph@codesourcery.com>
gcc/c/ChangeLog
PR c/79412
* c-decl.c (duplicate_decls): On significant mismatches, mark the
types of both (non-function) decls as error_mark_node, so that the
middle-end can see the code is malformed.
(free_attr_access_data): Don't process if the type has been set to
error_mark_node.
gcc/testsuite/ChangeLog
PR c/79412
* gcc.dg/pr79412.c: New test case.
* gcc.dg/typedef-var-2.c: Update expeted errors.
Diffstat (limited to 'gcc/testsuite/gcc.dg')
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr79412.c | 9 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/typedef-var-2.c | 5 |
2 files changed, 12 insertions, 2 deletions
diff --git a/gcc/testsuite/gcc.dg/pr79412.c b/gcc/testsuite/gcc.dg/pr79412.c new file mode 100644 index 0000000..b60d5e1 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr79412.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ +int a; +/* { dg-message "note: previous declaration" "previous declaration" { target *-*-* } .-1 } */ +void fn1 () +{ + a++; +} +int a[] = {2}; /* { dg-error "conflicting types" } */ diff --git a/gcc/testsuite/gcc.dg/typedef-var-2.c b/gcc/testsuite/gcc.dg/typedef-var-2.c index 716d29c..bc119a0 100644 --- a/gcc/testsuite/gcc.dg/typedef-var-2.c +++ b/gcc/testsuite/gcc.dg/typedef-var-2.c @@ -4,12 +4,13 @@ int f (void) { extern float v; - +/* { dg-message "note: previous declaration" "previous declaration" { target *-*-* } .-1 } */ return (v > 0.0f); } extern int t; +/* { dg-message "note: previous declaration" "previous declaration" { target *-*-* } .-1 } */ typedef float t; /* { dg-error "redeclared as different kind of symbol" } */ -t v = 4.5f; +t v = 4.5f; /* { dg-error "conflicting types" } */ |