[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 Martin Sebor changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #8 from Martin Sebor --- Patch committed in r257534.
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 --- Comment #7 from Martin Sebor --- Author: msebor Date: Fri Feb 9 17:58:54 2018 New Revision: 257534 URL: https://gcc.gnu.org/viewcvs?rev=257534=gcc=rev Log: PR lto/84212 - -Wno-* does not disable warnings from -flto link stage gcc/c-family/ChangeLog: PR lto/84212 * c.opt (-Wstringop-overflow, -Warray-bounds): Add LTO. (-Walloc-size-larger-than, -Wformat-truncation=): Same. (-Wmaybe-uninitialized, -Wnonnull, -Wrestrict): Same. (-Wstrict-overflow, -Wsuggest-attribute): Same. (-Wuninitialized): Same. gcc/testsuite/ChangeLog: PR lto/84212 * gcc.dg/lto/pr84212_0.c: New test file. * gcc.dg/lto/pr84212_1.c: Same. Added: trunk/gcc/testsuite/gcc.dg/lto/pr84212_0.c trunk/gcc/testsuite/gcc.dg/lto/pr84212_1.c Modified: trunk/gcc/c-family/ChangeLog trunk/gcc/c-family/c.opt trunk/gcc/testsuite/ChangeLog
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 Martin Sebor changed: What|Removed |Added Keywords||patch --- Comment #6 from Martin Sebor --- Patch: https://gcc.gnu.org/ml/gcc-patches/2018-02/msg00350.html
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 Martin Sebor changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |msebor at gcc dot gnu.org --- Comment #5 from Martin Sebor --- You're right. I fixed it for bug 78768 in r244326 (-Walloca-larger-than and -Wformat-overflow et al.) but missed -Wstringop-overflow. Let me take care of this. I wonder if LTO should be implied for all warnings to avoid these mistakes. Alternatively, have a script check to make sure that middle-end warnings are enabled for in the .opt file(s), run it for each build and fail if not.
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 --- Comment #4 from Richard Biener --- Wstringop-overflow C ObjC C++ ObjC++ Warning Alias(Wstringop-overflow=, 2, 0) Warn about buffer overflow in string manipulation functions like memcpy and strcpy. LTO is missing in the list of supported FEs. All middle-end warning also need that.
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 --- Comment #3 from Jay Foad --- Here you go: $ gcc -O3 -flto a.o b.o -Wno-stringop-overflow -v -### Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 7.2.0-8ubuntu3.1' --with-bugurl=file:///usr/share/doc/gcc-7/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr --with-gcc-major-version-only --program-suffix=-7 --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 --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-libmpx --enable-plugin --enable-default-pie --with-system-zlib --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 7.2.0 (Ubuntu 7.2.0-8ubuntu3.1) COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/7/:/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/7/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/7/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-O3' '-flto' '-Wstringop-overflow=0' '-v' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-linux-gnu/7/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/7/liblto_plugin.so "-plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/7/lto-wrapper" "-plugin-opt=-fresolution=/tmp/ccWxHzCo.res" "-plugin-opt=-pass-through=-lgcc" "-plugin-opt=-pass-through=-lgcc_s" "-plugin-opt=-pass-through=-lc" "-plugin-opt=-pass-through=-lgcc" "-plugin-opt=-pass-through=-lgcc_s" -flto "--sysroot=/" --build-id --eh-frame-hdr -m elf_x86_64 "--hash-style=gnu" --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie -z now -z relro /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/Scrt1.o /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/7/crtbeginS.o -L/usr/lib/gcc/x86_64-linux-gnu/7 -L/usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/7/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/7/../../.. a.o b.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-linux-gnu/7/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/crtn.o COLLECT_GCC_OPTIONS='-O3' '-flto' '-Wstringop-overflow=0' '-v' '-mtune=generic' '-march=x86-64'
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 Manuel López-Ibáñez changed: What|Removed |Added CC||manu at gcc dot gnu.org --- Comment #2 from Manuel López-Ibáñez --- This is strange. Is the driver passing the warning options to the LTO compiler? Does the LTO compiler process warning options or just drops them? Perhaps -v -### would clarify what is going on?
[Bug lto/84212] -Wno-* does not disable warnings from -flto link stage
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84212 Martin Sebor changed: What|Removed |Added Keywords||diagnostic Status|UNCONFIRMED |NEW Last reconfirmed||2018-02-05 CC||msebor at gcc dot gnu.org See Also||https://gcc.gnu.org/bugzill ||a/show_bug.cgi?id=71907, ||https://gcc.gnu.org/bugzill ||a/show_bug.cgi?id=78768, ||https://gcc.gnu.org/bugzill ||a/show_bug.cgi?id=79062 Ever confirmed|0 |1 Known to fail||7.3.0, 8.0 --- Comment #1 from Martin Sebor --- Confirmed with both 7.x where -Wstringop-overflow was first introduced and with 8.0, so it's not a regression. (A false positive would be, independent of this bug, if a test case is provided that reproduces it.) Prior to the introduction of -Wstringop-overflow GCC would print the same warning (minus the sizes) but with no option to suppress it. $ (gcc -D_FORTIFY_SOURCE=2 -O3 -flto'; $gcc -c a.c b.c && gcc a.o b.o) In function ‘memset’, inlined from ‘main’ at a.c:4:2: /usr/include/bits/string3.h:90:10: warning: call to __builtin___memset_chk will always overflow destination buffer return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest)); ^ See also pr71907, pr78768, and pr79062, for other problems with the interaction of -flto and some of these middle-end options.
