From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1666) id B85C63858421; Fri, 23 Jun 2023 10:30:00 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B85C63858421 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1687516200; bh=djpK0CwLlws93gOAE2/UZXjHHKAG2pgFe4dIji/WGtA=; h=From:To:Subject:Date:From; b=l1CYrJAwms2aroktNfB5kl4G7Q2fnf2Fkrtf5/fwFJX+RlIvhv/pvsYqtAnAkKfDB WIIZ0lPBP+tYvBLbBI8uxidU4NxBF6bamHZFPNfjLE0X78d2gZnTRkbHgb4WjQ5loa f3llU0m1gtOVzkxKLqzJa+fli92L6PlAlqLQBZxE= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Richard Biener To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-7467] middle-end/110055 - avoid CLOBBERing static variables X-Act-Checkin: gcc X-Git-Author: Richard Biener X-Git-Refname: refs/heads/releases/gcc-13 X-Git-Oldrev: a737da4885b7038fdd7d6646deaa1644efff2257 X-Git-Newrev: b0856bb588c76e16a518b459a8c9a012dc2b4e21 Message-Id: <20230623103000.B85C63858421@sourceware.org> Date: Fri, 23 Jun 2023 10:30:00 +0000 (GMT) List-Id: https://gcc.gnu.org/g:b0856bb588c76e16a518b459a8c9a012dc2b4e21 commit r13-7467-gb0856bb588c76e16a518b459a8c9a012dc2b4e21 Author: Richard Biener Date: Mon Jun 5 08:56:53 2023 +0200 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. (cherry picked from commit 84eec2916fa68cd2e2b3a2cf764f2ba595cce843) Diff: --- gcc/gimplify.cc | 4 +++- gcc/testsuite/g++.dg/warn/Wdangling-pointer-pr110055.C | 16 ++++++++++++++++ 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc index ade6e335da7..aece89a3e9b 100644 --- a/gcc/gimplify.cc +++ b/gcc/gimplify.cc @@ -7154,8 +7154,10 @@ 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 00000000000..77dbbf380b6 --- /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 +#include + +struct Data { + std::vector v = {1, 1}; +}; + +int main() +{ + Data a; + Data b; +}