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| author | Jakub Jelinek <jakub@redhat.com> | 2020-02-13 21:00:09 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-02-13 21:00:09 +0100 |
| commit | bacdd5e978dad84e9c547b0d5c7fed14b8d75157 (patch) | |
| tree | 32caf6b07a31366dba4ec9afff384714d0719f29 /gcc/c | |
| parent | 0a649b83751ce593e20bc9bda92ae52e64fd5cda (diff) | |
| download | gcc-bacdd5e978dad84e9c547b0d5c7fed14b8d75157.zip gcc-bacdd5e978dad84e9c547b0d5c7fed14b8d75157.tar.gz gcc-bacdd5e978dad84e9c547b0d5c7fed14b8d75157.tar.bz2 | |
c: Fix ICE with cast to VLA [93576]
The following testcase ICEs, because the PR84305 changes try to evaluate
the size earlier. If size has side-effects, that is desirable, and the
side-effects will actually be wrapped in a SAVE_EXPR. The problem on this
testcase is that there are no side-effects, and c_fully_fold doesn't fold
those COMPOUND_EXPRs to constant, and while before gimplification we unshare
trees found in the expressions, the unsharing doesn't involve TYPE_SIZE etc.
of used types. Gimplification is destructive though, so when we gimplify
the two nested COMPOUND_EXPRs and then try to gimplify it the second time
for the TYPE_SIZEs, we ICE.
Now, we could use unshare_expr in what we push to *expr, SAVE_EXPRs and
their operands in there aren't unshared, but I really don't see a point of
evaluating expressions that don't have side-effects before, so instead
this just pushes there expressions that do have side-effects.
2020-02-13 Jakub Jelinek <jakub@redhat.com>
PR c/93576
* c-decl.c (grokdeclarator): If this_size_varies, only push size into
*expr if it has side effects.
* gcc.dg/pr93576.c: New test.
Diffstat (limited to 'gcc/c')
| -rw-r--r-- | gcc/c/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/c/c-decl.c | 13 |
2 files changed, 14 insertions, 5 deletions
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog index 995f315..e88337b 100644 --- a/gcc/c/ChangeLog +++ b/gcc/c/ChangeLog @@ -1,3 +1,9 @@ +2020-02-13 Jakub Jelinek <jakub@redhat.com> + + PR c/93576 + * c-decl.c (grokdeclarator): If this_size_varies, only push size into + *expr if it has side effects. + 2020-01-30 Jeff Law <law@redhat.com> PR c/88660 diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c index 8281af7..1aa410d 100644 --- a/gcc/c/c-decl.c +++ b/gcc/c/c-decl.c @@ -6512,11 +6512,14 @@ grokdeclarator (const struct c_declarator *declarator, } if (this_size_varies) { - if (*expr) - *expr = build2 (COMPOUND_EXPR, TREE_TYPE (size), - *expr, size); - else - *expr = size; + if (TREE_SIDE_EFFECTS (size)) + { + if (*expr) + *expr = build2 (COMPOUND_EXPR, TREE_TYPE (size), + *expr, size); + else + *expr = size; + } *expr_const_operands &= size_maybe_const; } } |