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| author | Richard Biener <rguenther@suse.de> | 2023-06-05 08:56:53 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2023-06-06 09:19:35 +0200 |
| commit | 84eec2916fa68cd2e2b3a2cf764f2ba595cce843 (patch) | |
| tree | 5df3af4b06ca42be81bf7c14eb90e488aa4cbd1f /gcc | |
| parent | 21bf2b2fd99d7a94049610fc2f82db77f725d025 (diff) | |
| download | gcc-84eec2916fa68cd2e2b3a2cf764f2ba595cce843.zip gcc-84eec2916fa68cd2e2b3a2cf764f2ba595cce843.tar.gz gcc-84eec2916fa68cd2e2b3a2cf764f2ba595cce843.tar.bz2 | |
middle-end/110055 - avoid CLOBBERing static variables
The gimplifier can elide initialized constant automatic variables
to static storage in which case TARGET_EXPR gimplification needs
to avoid emitting a CLOBBER for them since their lifetime is no
longer limited. Failing to do so causes spurious dangling-pointer
diagnostics on the added testcase for some targets.
PR middle-end/110055
* gimplify.cc (gimplify_target_expr): Do not emit
CLOBBERs for variables which have static storage duration
after gimplifying their initializers.
* g++.dg/warn/Wdangling-pointer-pr110055.C: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/gimplify.cc | 4 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/warn/Wdangling-pointer-pr110055.C | 16 |
2 files changed, 19 insertions, 1 deletions
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc index bd5d0bf2..4aa6229 100644 --- a/gcc/gimplify.cc +++ b/gcc/gimplify.cc @@ -7174,8 +7174,10 @@ gimplify_target_expr (tree *expr_p, gimple_seq *pre_p, gimple_seq *post_p) gimplify_and_add (init, &init_pre_p); /* Add a clobber for the temporary going out of scope, like - gimplify_bind_expr. */ + gimplify_bind_expr. But only if we did not promote the + temporary to static storage. */ if (gimplify_ctxp->in_cleanup_point_expr + && !TREE_STATIC (temp) && needs_to_live_in_memory (temp)) { if (flag_stack_reuse == SR_ALL) diff --git a/gcc/testsuite/g++.dg/warn/Wdangling-pointer-pr110055.C b/gcc/testsuite/g++.dg/warn/Wdangling-pointer-pr110055.C new file mode 100644 index 0000000..77dbbf3 --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/Wdangling-pointer-pr110055.C @@ -0,0 +1,16 @@ +// { dg-do compile } +// { dg-require-effective-target c++11 } +// { dg-options "-O3 -fno-exceptions -Wdangling-pointer" } + +#include <cstdint> +#include <vector> + +struct Data { + std::vector<uint16_t> v = {1, 1}; +}; + +int main() +{ + Data a; + Data b; +} |