| Bug #109325 | compilation with gcc-11 or gcc-12 in RelWithDebInfo reports many warnings | ||
|---|---|---|---|
| Submitted: | 9 Dec 2022 10:58 | Modified: | 20 Dec 2022 15:08 |
| Reporter: | Przemysław Skibiński (OCA) | Email Updates: | |
| Status: | Won't fix | Impact on me: | |
| Category: | MySQL Server: Compiling | Severity: | S3 (Non-critical) |
| Version: | 8.0 | OS: | Ubuntu (Ubuntu 22.04.1 LTS) |
| Assigned to: | CPU Architecture: | x86 | |
[9 Dec 2022 11:25]
Przemysław Skibiński
The following patch works fine for me:
diff --git a/cmake/compile_flags.cmake b/cmake/compile_flags.cmake
index fe81e48fd58..10f0553b76b 100644
--- a/cmake/compile_flags.cmake
+++ b/cmake/compile_flags.cmake
@@ -127,6 +127,12 @@ FUNCTION(ADD_LINUX_DEB_FLAGS)
MESSAGE(FATAL_ERROR
"WITH_PACKAGE_FLAGS=on but dpkg-buildflags --get failed")
ENDIF()
+
+ # remove "-flto=auto -ffat-lto-objects" returned on Ubuntu 22.04
+ REMOVE_CMAKE_COMPILER_FLAGS(GET_CFLAGS "-flto(=[0-9a-z]+)?|-ffat-lto-objects")
+ REMOVE_CMAKE_COMPILER_FLAGS(GET_CXXFLAGS "-flto(=[0-9a-z]+)?|-ffat-lto-objects")
+ REMOVE_CMAKE_COMPILER_FLAGS(GET_LDFLAGS "-flto(=[0-9a-z]+)?|-ffat-lto-objects")
+
SET(CMAKE_C_FLAGS "${GET_CFLAGS} ${GET_CPPFLAGS}" PARENT_SCOPE)
SET(CMAKE_CXX_FLAGS "${GET_CXXFLAGS} ${GET_CPPFLAGS}" PARENT_SCOPE)
SET(CMAKE_EXE_LINKER_FLAGS "${GET_LDFLAGS}" PARENT_SCOPE)
[9 Dec 2022 13:17]
MySQL Verification Team
Hi Mr. Skibinski, Thank you for your bug report. Can you, please, let us know the outputs of the following commands: gcc --version and gcc -V Thanks a lot in advance.
[9 Dec 2022 13:34]
Przemysław Skibiński
Hi, there are warnings because Ubuntu 22.04 Jammy returns: $ dpkg-buildflags --get CXXFLAGS -g -O2 -ffile-prefix-map=/data/mysql-server=. -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security The same compilers on Ubuntu 20.04 will be fine because: $ dpkg-buildflags --get CXXFLAGS -g -O2 -fdebug-prefix-map=/data/docker=. -fstack-protector-strong -Wformat -Werror=format-security My gcc versions: $ gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.3.0-1ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-xKiWfi/gcc-11-11.3.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-xKiWfi/gcc-11-11.3.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2 Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04) $ gcc-12 -v Using built-in specs. COLLECT_GCC=gcc-12 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 12.1.0-2ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-12 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-12-sZcx2y/gcc-12-12.1.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-12-sZcx2y/gcc-12-12.1.0/debian/tmp-gcn/usr --enable-offload-defaulted --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 12.1.0 (Ubuntu 12.1.0-2ubuntu1~22.04)
[9 Dec 2022 14:23]
MySQL Verification Team
Hi, Since we are supporting Ubuntu 22.10, we are verifying this report. Verified.
[20 Dec 2022 15:08]
Tor Didriksen
Posted by developer: Our automated build system builds RPM or DEB packages, and most modern platforms have some builtin flags determined by dpkg-buildflags or 'rpm --eval %optflags' Developers build standalone builds, and by default we add WITH_PACKAGE_FLAGS to RelWithDebInfo builds, because we want the same flags as the automated build, otherwise we migth break it. Having a clean -flto build (on all platforms) is in practice impossible, since this is a moving target: change some code and the linker moves some other code around, and discovers some new 'may be unused'. But we *do* want to see those warnings, so that we can fix them. If you don't like the warnings, then simply turn WITH_PACKAGE_FLAGS OFF. Note that you will lose some performance if you do.
[21 Dec 2022 12:42]
MySQL Verification Team
Thank you, Tor .....
Description: Building MySQL Server 8.0.31 with the gcc-12 shows a lot of warnings: 1. /data/mysql-server/mysql-8.0/mysys/crypt_genhash_impl.cc: In function ‘my_make_scrambled_password’: /data/mysql-server/mysql-8.0/mysys/crypt_genhash_impl.cc:383:16: warning: ‘__builtin_strncat’ output may be truncated copying between 0 and 20 bytes from a string of length 20 [-Wstringop-truncation] 383 | (void)strncat(ctbuffer, (const char *)salt, salt_len); 2. /data/mysql-server/mysql-8.0/include/my_time.h: In function ‘convert_str_to_timestamp’: /data/mysql-server/mysql-8.0/include/my_time.h:200:19: warning: ‘__builtin_strncpy’ specified bound depends on the length of the source argument [-Wstringop-truncation] 200 | std::strncpy(m_deprecation.m_arg, arg, size); | ^ /data/mysql-server/mysql-8.0/client/mysqlbinlog.cc:2169:22: note: length computed here 2169 | if (str_to_datetime(str, strlen(str), &l_time, 0, &status) || 3. /data/mysql-server/mysql-8.0/sql/parser_yystype.h:348: warning: type ‘union YYSTYPE’ violates the C++ One Definition Rule [-Wodr] 348 | union YYSTYPE { | /data/mysql-server/mysql-8.0/storage/innobase/include/fts0pars.h:50: note: a different type is defined in another translation unit 50 | typedef union YYSTYPE | /data/mysql-server/mysql-8.0/sql/parser_yystype.h:349: note: the first difference of corresponding definitions is field ‘lexer’ 349 | Lexer_yystype lexer; // terminal values from the lexical scanner | storage/innobase/fts0pars.y:62: note: a field with different name is defined in another translation unit /data/mysql-server/mysql-8.0/sql/parser_yystype.h:348:7: warning: type ‘union YYSTYPE’ violates the C++ One Definition Rule [-Wodr] 348 | union YYSTYPE { | ^ /data/mysql-server/mysql-8.0/storage/innobase/include/fts0pars.h:50: note: a different type is defined in another translation unit 50 | typedef union YYSTYPE | /data/mysql-server/mysql-8.0/sql/parser_yystype.h:349:17: note: the first difference of corresponding definitions is field ‘lexer’ 349 | Lexer_yystype lexer; // terminal values from the lexical scanner | ^ ../storage/innobase/fts0pars.y:62: note: a field with different name is defined in another translation unit ./sql/sql_yacc.cc:570: warning: type ‘yysymbol_kind_t’ violates the C++ One Definition Rule [-Wodr] ./sql/sql_hints.yy.cc:137: note: an enum with different value name is defined in another translation unit ./sql/sql_yacc.cc:576: note: name ‘YYSYMBOL_ABORT_SYM’ differs from name ‘YYSYMBOL_MAX_EXECUTION_TIME_HINT’ defined in another translation unit ./sql/sql_hints.yy.cc:143: note: mismatching definition ./sql/sql_yacc.h:51: warning: type ‘yytokentype’ violates the C++ One Definition Rule [-Wodr] /data/mysql-server/mysql-8.0/storage/innobase/include/pars0grm.h:46: note: an enum with different value name is defined in another translation unit 46 | enum yytokentype { | ./sql/sql_yacc.h:53: note: name ‘YYEMPTY’ differs from name ‘PARS_INT_LIT’ defined in another translation unit /data/mysql-server/mysql-8.0/storage/innobase/include/pars0grm.h:47: note: mismatching definition 47 | PARS_INT_LIT = 258, 4. In member function ‘__ct ’, inlined from ‘__ct ’ at /data/mysql-server/_deps/boost_1_77_0/boost/geometry/srs/projections/proj/ob_tran.hpp:410:23, inlined from ‘__ct ’ at /data/mysql-server/_deps/boost_1_77_0/boost/geometry/srs/projections/proj/ob_tran.hpp:549:80, inlined from ‘__ct ’ at /data/mysql-server/_deps/boost_1_77_0/boost/geometry/srs/projections/impl/base_dynamic.hpp:116:38, inlined from ‘__ct ’ at /data/mysql-server/_deps/boost_1_77_0/boost/geometry/srs/projections/impl/base_dynamic.hpp:147:33, inlined from ‘create_new’ at /data/mysql-server/_deps/boost_1_77_0/boost/geometry/srs/projections/proj/ob_tran.hpp:618:24: /data/mysql-server/_deps/boost_1_77_0/boost/geometry/srs/projections/proj/ob_tran.hpp:182:20: warning: ‘proj_parm.sphip’ may be used uninitialized [-Wmaybe-uninitialized] 182 | struct par_ob_tran | ^ 5. In member function ‘__ct ’, inlined from ‘unpack_varbinary’ at /data/mysql-server/mysql-8.0/storage/ndb/plugin/ndb_util_table.cc:436:55: /usr/include/c++/12/bits/basic_string.h:617:17: warning: ‘unpacked_str’ may be used uninitialized [-Wmaybe-uninitialized] 617 | if (__s == 0 && __n > 0) | ^ /data/mysql-server/mysql-8.0/storage/ndb/plugin/ndb_util_table.cc: In member function ‘unpack_varbinary’: /data/mysql-server/mysql-8.0/storage/ndb/plugin/ndb_util_table.cc:431:15: note: ‘unpacked_str’ was declared here 431 | const char *unpacked_str; | ^ 6. In function ‘make_unique’, inlined from ‘operator()’ at /data/mysql-server/mysql-8.0/unittest/gunit/innodb/sync0rw-t.cc:169:48: /usr/include/c++/12/bits/unique_ptr.h:1080:30: warning: argument 1 value ‘18446744073709551615’ exceeds maximum object size 9223372036854775807 [-Walloc-size-larger-than=] 1080 | { return unique_ptr<_Tp>(new remove_extent_t<_Tp>[__num]()); } | ^ /usr/include/c++/12/new: In member function ‘operator()’: /usr/include/c++/12/new:128:26: note: in a call to allocation function ‘operator new []’ declared here 128 | _GLIBCXX_NODISCARD void* operator new[](std::size_t) _GLIBCXX_THROW (std::bad_alloc) How to repeat: git clone https://github.com/mysql/mysql-server.git mkdir mysql-build cd mysql-build cmake .. -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_C_COMPILER=gcc-12 -DCMAKE_CXX_COMPILER=g++-12 -DBUILD_CONFIG=mysql_release Suggested fix: There is not a single warning when adding "-DWITH_PACKAGE_FLAGS=OFF". Why? All those issues are related to using "-flto=auto -ffat-lto-objects" in CMAKE_CXX_FLAGS. I didn't use "-DWITH_LTO=ON". Who sets "-flto" then? ADD_LINUX_DEB_FLAGS() calls "dpkg-buildflags --get CXXFLAGS" and appends a result to CMAKE_CXX_FLAGS. Ubuntu 22.04 Jammy returns: $ dpkg-buildflags --get CXXFLAGS -g -O2 -ffile-prefix-map=/data/mysql-server=. -flto=auto -ffat-lto-objects -flto=auto -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security Suggested fix: Auto-remove "-flto=auto -ffat-lto-objects" from a dpkg-buildflags result.