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| author |   Michał Górny <mgorny@gentoo.org> | 2017-08-11 17:17:45 +0200 |
|---|---|---|
| committer | Michał Górny <mgorny@gentoo.org> | 2017-08-25 15:53:15 +0200 |
| commit | ae9870d9f6b1394ede86176443770b36d7e60ac1 (patch) | |
| tree | 5f533b8f8651d035ac7cb0f0a6111148dfc13533 /eclass | |
| parent | flag-o-matic.eclass: test-flag-PROG, refactor to reduce duplication (diff) | |
| download | gentoo-ae9870d9f6b1394ede86176443770b36d7e60ac1.tar.gz gentoo-ae9870d9f6b1394ede86176443770b36d7e60ac1.tar.bz2 gentoo-ae9870d9f6b1394ede86176443770b36d7e60ac1.zip | |
flag-o-matic.eclass: test-flag-PROG, ignore unused args in clang
By default, clang considers unused arguments as error when -Werror is
used. Since flag tests are performed without linking, this causes all
tests for linker flags to fail inadvertently and all those flags
are stripped as a result.
While the correctness of passing unused flags is doubtful, silently
stripping them in a few random packages is certainly not the solution
to the problem, and also makes the results differ between gcc and clang.
To account for that, use clang's -Qunused-arguments option to silence
unused argument warnings.
To avoid wasting time on testing the compiler, just try passing
-Qunused-arguments every time a flag check fails. If clang is not used,
the additional call will fail just the same as the previous one (either
because of the original flag or because of -Qunused-arguments), so
the result will be the same.
Diffstat (limited to 'eclass')
| -rw-r--r-- | eclass/flag-o-matic.eclass | 9 | ||||
| -rwxr-xr-x | eclass/tests/flag-o-matic.sh | 5 |
2 files changed, 13 insertions, 1 deletions
diff --git a/eclass/flag-o-matic.eclass b/eclass/flag-o-matic.eclass index 0393a30b74c3..79866e04a483 100644 --- a/eclass/flag-o-matic.eclass +++ b/eclass/flag-o-matic.eclass @@ -441,7 +441,14 @@ test-flag-PROG() { cmdline+=( "${flag}" -c -o /dev/null /dev/null ) fi - "${cmdline[@]}" </dev/null &>/dev/null + if ! "${cmdline[@]}" </dev/null &>/dev/null; then + # -Werror makes clang bail out on unused arguments as well; + # try to add -Qunused-arguments to work-around that + # other compilers don't support it but then, it's failure like + # any other + cmdline+=( -Qunused-arguments ) + "${cmdline[@]}" </dev/null &>/dev/null + fi } # @FUNCTION: test-flag-CC diff --git a/eclass/tests/flag-o-matic.sh b/eclass/tests/flag-o-matic.sh index 92c68b82c3c9..5e7ee354bf33 100755 --- a/eclass/tests/flag-o-matic.sh +++ b/eclass/tests/flag-o-matic.sh @@ -143,6 +143,11 @@ tbegin "test-flags-CC (gcc-valid but clang-invalid flags)" out=$(CC=clang test-flags-CC -finline-limit=1200) [[ $? -ne 0 && -z ${out} ]] ftend + +tbegin "test-flags-CC (unused flags w/clang)" +out=$(CC=clang test-flags-CC -Wl,-O1) +[[ $? -eq 0 && ${out} == "-Wl,-O1" ]] +ftend fi texit |