https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109475
Bug ID: 109475 Summary: How to check for default compiler warnings in g++ 8.4.0 Product: gcc Version: 8.4.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: other Assignee: unassigned at gcc dot gnu.org Reporter: jorge.pinto.sousa at proton dot me Target Milestone: --- Hello, I was trying to get the list of warnings enabled by default from gcc and where to get that info from. Looked in to the manual and found that we could get a list of the warnings enabled by doing: > /usr/bin/gcc-8 -Q --help=warnings | grep enabled but then some warnings despite being listed there were not triggered: https://godbolt.org/z/GGnjcjxKh Like -Wtrigraphs for example: > gcc -Q --help=warning | grep trigraph > -Wtrigraphs [enabled] I then tried to compile that example locally by dumping all the flags: > gcc -Q -v foo.cpp which (I think) dumps (all) the compilation and linking flags, and the only warnings I got there are: > options passed: -v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE foo.cpp > -mtune=generic -march=x86-64 -Wctor-dtor-privacy > -fasynchronous-unwind-tables -fstack-protector-strong -Wformat > -Wformat-security -fstack-clash-protection -fcf-protection > options enabled: -fPIC -fPIE -faggressive-loop-optimizations > (...) That is : > -Wformat > -Wformat-security So we can say that these are the only two that are default enabled? (I also looked into https://gcc.gnu.org/onlinedocs/gcc-8.4.0/gcc/Option-Summary.html but could not find any pointers). Would like to know where one can get the correct list for these. Note that I am not talking about -Wall or anything. Just the list of warnings that is enabled by default, without adding any other flags.