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From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c/101537] -Wconversion false positive in ternary and |= Date: Tue, 11 Jan 2022 18:15:12 +0000 [thread overview] Message-ID: <bug-101537-4-nuNOsVEYx0@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-101537-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101537 --- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>: https://gcc.gnu.org/g:20e4a5e573e76f4379b353cc736215a5f10cdb84 commit r12-6486-g20e4a5e573e76f4379b353cc736215a5f10cdb84 Author: Jakub Jelinek <jakub@redhat.com> Date: Tue Jan 11 19:11:51 2022 +0100 c-family: Fix up -W*conversion on bitwise &/|/^ [PR101537] The following testcases emit a bogus -Wconversion warning. This is because conversion_warning function doesn't handle BIT_*_EXPR (only unsafe_conversion_p that is called during the default: case, and that one doesn't handle SAVE_EXPRs added because the unsigned char & or | operands promoted to int have side-effects and =| or =& is used. The patch handles BIT_IOR_EXPR/BIT_XOR_EXPR like the last 2 operands of COND_EXPR by recursing on the two operands, if either of them doesn't fit into the narrower type, complain. BIT_AND_EXPR too, but first it needs to handle some special cases that unsafe_conversion_p does, namely when one of the two operands is a constant. This fixes completely the pr101537.c test and for C also pr103881.c and doesn't regress anything in the testsuite, for C++ pr103881.c still emits the bogus warnings. This is because while the C FE emits in that case a SAVE_EXPR that conversion_warning can handle already, C++ FE emits TARGET_EXPR <D.whatever, ...>, something | D.whatever etc. and conversion_warning handles COMPOUND_EXPR by "recursing" on the rhs. To handle that case, we'd need for TARGET_EXPR on the lhs remember in some hash map the mapping from D.whatever to the TARGET_EXPR and when we see D.whatever, use corresponding TARGET_EXPR initializer instead. 2022-01-11 Jakub Jelinek <jakub@redhat.com> PR c/101537 PR c/103881 gcc/c-family/ * c-warn.c (conversion_warning): Handle BIT_AND_EXPR, BIT_IOR_EXPR and BIT_XOR_EXPR. gcc/testsuite/ * c-c++-common/pr101537.c: New test. * c-c++-common/pr103881.c: New test.
next prev parent reply other threads:[~2022-01-11 18:15 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-20 17:41 [Bug c++/101537] New: -Wconversion false positive in ternary me at xenu dot pl 2021-08-08 15:15 ` [Bug c++/101537] " nok.raven at gmail dot com 2021-08-12 23:47 ` [Bug c/101537] -Wconversion false positive in ternary and |= pinskia at gcc dot gnu.org 2021-12-31 17:25 ` thomas at habets dot se 2021-12-31 22:34 ` jakub at gcc dot gnu.org 2022-01-03 11:52 ` jakub at gcc dot gnu.org 2022-01-11 18:15 ` cvs-commit at gcc dot gnu.org [this message] 2022-01-24 9:21 ` cvs-commit at gcc dot gnu.org 2022-05-10 8:22 ` cvs-commit at gcc dot gnu.org 2023-06-29 15:31 ` wolter.hellmundvega at tevva dot com
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