From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 397DD3893676 for ; Wed, 6 May 2020 03:32:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 397DD3893676 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tdevries@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id B7CA2ADD3 for ; Wed, 6 May 2020 03:32:10 +0000 (UTC) Subject: [committed][gdb/testsuite] Compile compile-ifunc.c with -Wno-attribute-alias From: Tom de Vries To: gdb-patches@sourceware.org References: <20200501142617.GA31389@delia> Autocrypt: addr=tdevries@suse.de; keydata= xsBNBF0ltCcBCADDhsUnMMdEXiHFfqJdXeRvgqSEUxLCy/pHek88ALuFnPTICTwkf4g7uSR7 HvOFUoUyu8oP5mNb4VZHy3Xy8KRZGaQuaOHNhZAT1xaVo6kxjswUi3vYgGJhFMiLuIHdApoc u5f7UbV+egYVxmkvVLSqsVD4pUgHeSoAcIlm3blZ1sDKviJCwaHxDQkVmSsGXImaAU+ViJ5l CwkvyiiIifWD2SoOuFexZyZ7RUddLosgsO0npVUYbl6dEMq2a5ijGF6/rBs1m3nAoIgpXk6P TCKlSWVW6OCneTaKM5C387972qREtiArTakRQIpvDJuiR2soGfdeJ6igGA1FZjU+IsM5ABEB AAHNH1RvbSBkZSBWcmllcyA8dGRldnJpZXNAc3VzZS5kZT7CwKsEEwEIAD4WIQSsnSe5hKbL MK1mGmjuhV2rbOJEoAUCXSW0JwIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAh CRDuhV2rbOJEoBYhBKydJ7mEpsswrWYaaO6FXats4kSgc48H/Ra2lq5p3dHsrlQLqM7N68Fo eRDf3PMevXyMlrCYDGLVncQwMw3O/AkousktXKQ42DPJh65zoXB22yUt8m0g12xkLax98KFJ 5NyUloa6HflLl+wQL/uZjIdNUQaHQLw3HKwRMVi4l0/Jh/TygYG1Dtm8I4o708JS4y8GQxoQ UL0z1OM9hyM3gI2WVTTyprsBHy2EjMOu/2Xpod95pF8f90zBLajy6qXEnxlcsqreMaqmkzKn 3KTZpWRxNAS/IH3FbGQ+3RpWkNGSJpwfEMVCeyK5a1n7yt1podd1ajY5mA1jcaUmGppqx827 8TqyteNe1B/pbiUt2L/WhnTgW1NC1QDOwE0EXSW0JwEIAM99H34Bu4MKM7HDJVt864MXbx7B 1M93wVlpJ7Uq+XDFD0A0hIal028j+h6jA6bhzWto4RUfDl/9mn1StngNVFovvwtfzbamp6+W pKHZm9X5YvlIwCx131kTxCNDcF+/adRW4n8CU3pZWYmNVqhMUiPLxElA6QhXTtVBh1RkjCZQ Kmbd1szvcOfaD8s+tJABJzNZsmO2hVuFwkDrRN8Jgrh92a+yHQPd9+RybW2l7sJv26nkUH5Z 5s84P6894ebgimcprJdAkjJTgprl1nhgvptU5M9Uv85Pferoh2groQEAtRPlCGrZ2/2qVNe9 XJfSYbiyedvApWcJs5DOByTaKkcAEQEAAcLAkwQYAQgAJhYhBKydJ7mEpsswrWYaaO6FXats 4kSgBQJdJbQnAhsMBQkDwmcAACEJEO6FXats4kSgFiEErJ0nuYSmyzCtZhpo7oVdq2ziRKD3 twf7BAQBZ8TqR812zKAD7biOnWIJ0McV72PFBxmLIHp24UVe0ZogtYMxSWKLg3csh0yLVwc7 H3vldzJ9AoK3Qxp0Q6K/rDOeUy3HMqewQGcqrsRRh0NXDIQk5CgSrZslPe47qIbe3O7ik/MC q31FNIAQJPmKXX25B115MMzkSKlv4udfx7KdyxHrTSkwWZArLQiEZj5KG4cCKhIoMygPTA3U yGaIvI/BGOtHZ7bEBVUCFDFfOWJ26IOCoPnSVUvKPEOH9dv+sNy7jyBsP5QxeTqwxC/1ZtNS DUCSFQjqA6bEGwM22dP8OUY6SC94x1G81A9/xbtm9LQxKm0EiDH8KBMLfQ== Message-ID: Date: Wed, 6 May 2020 05:32:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200501142617.GA31389@delia> Content-Type: multipart/mixed; boundary="------------E413C2800A26578334C0CD58" Content-Language: en-US X-Spam-Status: No, score=-20.5 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 May 2020 03:32:13 -0000 This is a multi-part message in MIME format. --------------E413C2800A26578334C0CD58 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 01-05-2020 16:26, Tom de Vries wrote: > Fix the warning by compiling with -Wno-attribute-alias. I ran into this with clang: ... warning: unknown warning option '-Wno-attribute-alias'; did you mean^M '-Wno-attributes'? [-Wunknown-warning-option]^M ... So, I've limited the fix to when gcc is used. Committed. Thanks, - Tom --------------E413C2800A26578334C0CD58 Content-Type: text/x-patch; charset=UTF-8; name="0001-gdb-testsuite-Compile-compile-ifunc.c-with-Wno-attribute-alias.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0001-gdb-testsuite-Compile-compile-ifunc.c-with-Wno-attribut"; filename*1="e-alias.patch" [gdb/testsuite] Compile compile-ifunc.c with -Wno-attribute-alias Consider the following test-case: ... $ cat 1.c typedef int (*final_t) (int arg); int final (int arg) { return arg + 1; } final_t gnu_ifunc (void) { return final; } int gnu_ifunc_alias (int) __attribute__ ((ifunc ("gnu_ifunc"))); int main (void) { return gnu_ifunc_alias (10); } ... with result: ... $ gcc 1.c $ ./a.out; echo $? 11 ... The test-case uses the ifunc attribute, but there's another solution using %gnu_indirect_function. Consider 2.c and 3.c: ... $ cat 2.c typedef int (*final_t) (int arg); int final (int arg) { return arg + 1; } asm (".type gnu_ifunc, %gnu_indirect_function"); final_t gnu_ifunc (void) { return final; } $ cat 3.c extern int gnu_ifunc (int); int main (void) { return gnu_ifunc (10); } ... However, it can be inconvenient to have seperate files for the incompatible decls of gnu_ifunc, so we can use this in a single file like this: ... $ cat 4.c typedef int (*final_t) (int arg); int final (int arg) { return arg + 1; } asm (".type gnu_ifunc, %gnu_indirect_function"); final_t gnu_ifunc (void) { return final; } extern int gnu_ifunc_alias (int arg) __attribute__ ((alias ("gnu_ifunc"))); int main (void) { return gnu_ifunc_alias (10); } ... This alias trick works ok at -O0, but not at -O2: ... $ gcc 4.c $ ./a.out; echo $? 11 $ gcc 4.c $ ./a.out; echo $? 176 ... and produces a warning with gcc-8 and later: ... $ gcc-8 4.c 4.c:7:12: warning: 'gnu_ifunc_alias' alias between functions of incompatible \ types 'int(int)' and 'int (*(void))(int)' [-Wattribute-alias] extern int gnu_ifunc_alias (int arg) __attribute__ ((alias ("gnu_ifunc"))); ^~~~~~~~~~~~~~~ 4.c:5:9: note: aliased declaration here final_t gnu_ifunc (void) ^~~~~~~~~ ... The warning is correct, but the mismatch is intentional. The last variant (%gnu_indirect_function + alias) is used in gdb.compile/compile-ifunc.c, so we run into the warning with recent gcc. Fix the warning by compiling with -Wno-attribute-alias. Tested the test-case on x86_64-linux with gcc-10, and observed I no longer see the warning: ... Running src/gdb/testsuite/gdb.compile/compile-ifunc.exp ... === gdb Summary === nr of untested testcases 1 ... gdb/testsuite/ChangeLog: 2020-05-01 Tom de Vries * gdb.compile/compile-ifunc.exp: Use -Wno-attribute-alias. --- gdb/testsuite/gdb.compile/compile-ifunc.exp | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/gdb/testsuite/gdb.compile/compile-ifunc.exp b/gdb/testsuite/gdb.compile/compile-ifunc.exp index ff81e2f87aa..9239c5adf1e 100644 --- a/gdb/testsuite/gdb.compile/compile-ifunc.exp +++ b/gdb/testsuite/gdb.compile/compile-ifunc.exp @@ -19,9 +19,16 @@ if {[skip_ifunc_tests]} { standard_testfile +get_compiler_info +set flags "" +if [test_compiler_info gcc*] { + set flags additional_flags=-Wno-attribute-alias +} + with_test_prefix "nodebug" { - if { [prepare_for_testing "failed to prepare" "$testfile-nodebug" $srcfile {}] } { + if { [prepare_for_testing "failed to prepare" "$testfile-nodebug" \ + $srcfile $flags] } { return -1 } @@ -51,7 +58,8 @@ with_test_prefix "nodebug" { with_test_prefix "debug" { - if { [prepare_for_testing "failed to prepare" "$testfile-debug" $srcfile] } { + if { [prepare_for_testing "failed to prepare" "$testfile-debug" \ + $srcfile "debug $flags"] } { return -1 } --------------E413C2800A26578334C0CD58--