[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 uecker at gcc dot gnu.org changed: What|Removed |Added Resolution|--- |FIXED CC||uecker at gcc dot gnu.org Known to fail||4.9.0 Target Milestone|--- |14.0 Status|NEW |RESOLVED --- Comment #9 from uecker at gcc dot gnu.org --- Fixed on trunk.
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 --- Comment #8 from CVS Commits --- The master branch has been updated by Martin Uecker : https://gcc.gnu.org/g:54be338589ea93ad4ff53d22adde476a0582537b commit r14-3004-g54be338589ea93ad4ff53d22adde476a0582537b Author: Martin Uecker Date: Fri Aug 4 07:48:21 2023 +0200 c: _Generic should not warn in non-active branches [PR68193,PR97100,PR110703] To avoid false diagnostics, use c_inhibit_evaluation_warnings when a generic association is known to not match during parsing. We may still generate false positives if the default branch comes earler than a specific association that matches. PR c/68193 PR c/97100 PR c/110703 gcc/c/: * c-parser.cc (c_parser_generic_selection): Inhibit evaluation warnings branches that are known not be taken during parsing. gcc/testsuite/ChangeLog: * gcc.dg/pr68193.c: New test.
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 Martin Uecker changed: What|Removed |Added CC||muecker at gwdg dot de --- Comment #7 from Martin Uecker --- PATCH: https://gcc.gnu.org/pipermail/gcc-patches/2023-August/626319.html
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 Ladislav Michl changed: What|Removed |Added CC||la...@linux-mips.org --- Comment #6 from Ladislav Michl --- Created attachment 46391 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46391&action=edit Ternary if That ternary operator makes warning disappear. In the testcase 'gcc -Woverflow -o x x.c' gives: x.c:14:9: warning: unsigned conversion from ‘int’ to ‘unsigned char’ changes value from ‘1000’ to ‘232’ [-Woverflow] baz = 1000; ^~~~ x.c:16:9: warning: unsigned conversion from ‘int’ to ‘unsigned char’ changes value from ‘2000’ to ‘208’ [-Woverflow] baz = 2000; ^~~~ while 'gcc -DNO -Woverflow -o x x.c' silently ignores overflow. I would welcome any advice, how o properly categorize this bug, so eventually new bugreport will be created. Thank you.
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 --- Comment #5 from Marek Polacek --- Yes, so this would be somehow tied to c_inhibit_evaluation_warnings as in we warn for 0 ? foo () : 2; if foo() wasn't declared but not for the div-by-zero here: 0 ? 1 / 0 : 2;
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 --- Comment #4 from joseph at codesourcery dot com --- I agree delaying warnings would help, but you'd need to distinguish warnings relating to execution of the code that should be disabled in unevaluated code from warnings that should always be present (which include but aren't limited to pedwarns). For example, you shouldn't lose a diagnostic for an implicit function declaration just because it's in an unevaluated _Generic selection.
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 --- Comment #3 from Marek Polacek --- I think some kind of delayed warning could help (so parse expressions and print possible warnings to some "printer" and then print warnings from this "printer" only for the association that matched). Because of "default:" selectors we can't parse just the one that matches.
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 Marek Polacek changed: What|Removed |Added CC||mpolacek at gcc dot gnu.org --- Comment #2 from Marek Polacek --- The problem here is that after we've parsed the selector (with warnings inhibited), we go over all the associations: process the type-name, then parse assignment-expression of the association also using c_parser_expr_no_commas, but this time without the warnings inhibited. We should probably disable warnings when processing the associations and only warn for matched_assoc. But I can't readily conceive how to do that.
[Bug c/68193] _Generic -Woverflow false alarm
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 Richard Biener changed: What|Removed |Added Keywords||diagnostic Status|UNCONFIRMED |NEW Last reconfirmed||2015-11-03 Ever confirmed|0 |1 --- Comment #1 from Richard Biener --- Confirmed.
