commit: 9c5a9175843ce79427b04a5f23927a415d78d057 Author: Sergei Trofimovich <slyfox <AT> gentoo <DOT> org> AuthorDate: Thu Mar 26 08:22:50 2020 +0000 Commit: Sergei Trofimovich <slyfox <AT> gentoo <DOT> org> CommitDate: Thu Mar 26 08:23:59 2020 +0000 URL: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=9c5a9175
flag-o-matic.eclass: document assumptions and limitations of test-flag-PROG() Bug: https://bugs.gentoo.org/712488 Signed-off-by: Sergei Trofimovich <slyfox <AT> gentoo.org> eclass/flag-o-matic.eclass | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/eclass/flag-o-matic.eclass b/eclass/flag-o-matic.eclass index 9ef9ac3685e..e76eef293e8 100644 --- a/eclass/flag-o-matic.eclass +++ b/eclass/flag-o-matic.eclass @@ -487,6 +487,17 @@ test-flag-PROG() { printf "%s\n" "${in_src}" > "${test_in}" || die "Failed to create '${test_in}'" + # Currently we rely on warning-free output of a compiler + # before the flag to see if a flag prduces any warnings. + # This has a few drawbacks: + # - if compiler already generates warnings we filter out + # every single flag: bug #712488 + # - if user actually wants to see warnings we just strip + # them regardless of warnings type. + # + # We can add more selective detection of no-op flags via + # '-Werror=ignored-optimization-argument' and similar error options + # similar to what we are doing with '-Qunused-arguments'. local cmdline=( "${comp[@]}" # Clang will warn about unknown gcc flags but exit 0.
