* [gentoo-dev] [PATCH 1/3] flag-o-matic.eclass: test-flag-PROG, refactor to reduce duplication
2017-08-11 15:26 [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two Michał Górny
@ 2017-08-11 15:26 ` Michał Górny
2017-08-11 15:26 ` [gentoo-dev] [PATCH 2/3] flag-o-matic.eclass: test-flag-PROG, ignore unused args in clang Michał Górny
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Michał Górny @ 2017-08-11 15:26 UTC (permalink / raw
To: gentoo-dev; +Cc: Michał Górny
---
eclass/flag-o-matic.eclass | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/eclass/flag-o-matic.eclass b/eclass/flag-o-matic.eclass
index b2f3742b3ecf..0393a30b74c3 100644
--- a/eclass/flag-o-matic.eclass
+++ b/eclass/flag-o-matic.eclass
@@ -433,11 +433,15 @@ test-flag-PROG() {
# Use -c so we can test the assembler as well.
-c -o /dev/null
)
- if "${cmdline[@]}" -x${lang} - </dev/null >/dev/null 2>&1 ; then
- "${cmdline[@]}" "${flag}" -x${lang} - </dev/null >/dev/null 2>&1
+ if "${cmdline[@]}" -x${lang} - </dev/null &>/dev/null ; then
+ cmdline+=( "${flag}" -x${lang} - )
else
- "${cmdline[@]}" "${flag}" -c -o /dev/null /dev/null >/dev/null 2>&1
+ # XXX: what's the purpose of this? does it even work with
+ # any compiler?
+ cmdline+=( "${flag}" -c -o /dev/null /dev/null )
fi
+
+ "${cmdline[@]}" </dev/null &>/dev/null
}
# @FUNCTION: test-flag-CC
--
2.14.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [gentoo-dev] [PATCH 2/3] flag-o-matic.eclass: test-flag-PROG, ignore unused args in clang
2017-08-11 15:26 [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two Michał Górny
2017-08-11 15:26 ` [gentoo-dev] [PATCH 1/3] flag-o-matic.eclass: test-flag-PROG, refactor to reduce duplication Michał Górny
@ 2017-08-11 15:26 ` Michał Górny
2017-08-11 15:26 ` [gentoo-dev] [PATCH 3/3] flag-o-matic.eclass: Strip LDFLAGS unsupported by the C compiler, #621274 Michał Górny
2017-08-25 13:53 ` [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two Michał Górny
3 siblings, 0 replies; 5+ messages in thread
From: Michał Górny @ 2017-08-11 15:26 UTC (permalink / raw
To: gentoo-dev; +Cc: Michał Górny
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.
---
eclass/flag-o-matic.eclass | 9 ++++++++-
eclass/tests/flag-o-matic.sh | 5 +++++
2 files changed, 13 insertions(+), 1 deletion(-)
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 && ${out} == "-Wl,-O1" ]]
+ftend
fi
texit
--
2.14.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [gentoo-dev] [PATCH 3/3] flag-o-matic.eclass: Strip LDFLAGS unsupported by the C compiler, #621274
2017-08-11 15:26 [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two Michał Górny
2017-08-11 15:26 ` [gentoo-dev] [PATCH 1/3] flag-o-matic.eclass: test-flag-PROG, refactor to reduce duplication Michał Górny
2017-08-11 15:26 ` [gentoo-dev] [PATCH 2/3] flag-o-matic.eclass: test-flag-PROG, ignore unused args in clang Michał Górny
@ 2017-08-11 15:26 ` Michał Górny
2017-08-25 13:53 ` [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two Michał Górny
3 siblings, 0 replies; 5+ messages in thread
From: Michał Górny @ 2017-08-11 15:26 UTC (permalink / raw
To: gentoo-dev; +Cc: Michał Górny
Include LDFLAGS in the variables stripped by strip-unsupported-flags.
The code reuses the current functions for testing CC, and so only remove
LDFLAGS that are rejected by the C compiler and not the linker. This
solves the case of bug #621274 where LDFLAGS contained GCC-specific
-flto flag.
---
eclass/flag-o-matic.eclass | 3 +++
eclass/tests/flag-o-matic.sh | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/eclass/flag-o-matic.eclass b/eclass/flag-o-matic.eclass
index 79866e04a483..4e3cfff5afd5 100644
--- a/eclass/flag-o-matic.eclass
+++ b/eclass/flag-o-matic.eclass
@@ -546,6 +546,9 @@ strip-unsupported-flags() {
export CXXFLAGS=$(test-flags-CXX ${CXXFLAGS})
export FFLAGS=$(test-flags-F77 ${FFLAGS})
export FCFLAGS=$(test-flags-FC ${FCFLAGS})
+ # note: this does not verify the linker flags but it is enough
+ # to strip invalid C flags which are much more likely, #621274
+ export LDFLAGS=$(test-flags-CC ${LDFLAGS})
}
# @FUNCTION: get-flag
diff --git a/eclass/tests/flag-o-matic.sh b/eclass/tests/flag-o-matic.sh
index 5e7ee354bf33..53af9f862c41 100755
--- a/eclass/tests/flag-o-matic.sh
+++ b/eclass/tests/flag-o-matic.sh
@@ -55,7 +55,7 @@ done <<<"
tbegin "strip-unsupported-flags"
strip-unsupported-flags
-[[ ${CFLAGS} == "" ]] && [[ ${CXXFLAGS} == "-z=2" ]]
+[[ ${CFLAGS} == "" ]] && [[ ${CXXFLAGS} == "-z=2" ]] && [[ ${LDFLAGS} == "" ]]
ftend
for var in $(all-flag-vars) ; do
--
2.14.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two
2017-08-11 15:26 [gentoo-dev] [PATCH] flag-o-matic.eclass: LDFLAGS stripping, take two Michał Górny
` (2 preceding siblings ...)
2017-08-11 15:26 ` [gentoo-dev] [PATCH 3/3] flag-o-matic.eclass: Strip LDFLAGS unsupported by the C compiler, #621274 Michał Górny
@ 2017-08-25 13:53 ` Michał Górny
3 siblings, 0 replies; 5+ messages in thread
From: Michał Górny @ 2017-08-25 13:53 UTC (permalink / raw
To: gentoo-dev
W dniu pią, 11.08.2017 o godzinie 17∶26 +0200, użytkownik Michał Górny
napisał:
> Hi, everyone.
>
> I've just reverted the LDFLAGS stripping code I've committed earlier
> because it failed hard with clang. Here's an updated patch set that
> ensures that clang is going to work fine. Please review.
>
Merged now.
--
Best regards,
Michał Górny
^ permalink raw reply [flat|nested] 5+ messages in thread