https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79791
Bug ID: 79791 Summary: -Werror=write-strings ignored with -Wpedantic Product: gcc Version: 6.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: federico.kircheis at gmail dot com Target Milestone: --- Given following program: int main(){ char* str = "hello world!"; (void)str; } When compiling with "-Werror=write-strings", the expected output would be a compiler error. This is what happens when compiling with: "g++ -Werror=write-strings main.cpp" The output on the command line contains (an no executable is produced): "error: ISO C++ forbids converting a string constant to ‘char*’ [-Werror=write-strings]" The problem is that apparently "-Wpedantic" overwrites "-Werror=write-strings", even if that option is given after pedantic: g++ -v -Wpedantic -Werror=write-strings main.cpp Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/6/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 6.3.0-6' --with-bugurl=file:///usr/share/doc/gcc-6/README.Bugs --enable-languages=c,ada,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-6 --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 --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-6-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-6-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-6-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --with-target-system-zlib --enable-objc-gc=auto --enable-multiarch --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 6.3.0 20170205 (Debian 6.3.0-6) COLLECT_GCC_OPTIONS='-v' '-Wpedantic' '-Werror=write-strings' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-linux-gnu/6/cc1plus -quiet -v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE main.cpp -quiet -dumpbase main.cpp -mtune=generic -march=x86-64 -auxbase main -Wpedantic -Werror=write-strings -version -o /tmp/ccPbVEN2.s GNU C++14 (Debian 6.3.0-6) version 6.3.0 20170205 (x86_64-linux-gnu) compiled by GNU C version 6.3.0 20170205, GMP version 6.1.2, MPFR version 3.1.5, MPC version 1.0.3, isl version 0.15 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 ignoring duplicate directory "/usr/include/x86_64-linux-gnu/c++/6" ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/6/../../../../x86_64-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/6 /usr/include/x86_64-linux-gnu/c++/6 /usr/include/c++/6/backward /usr/lib/gcc/x86_64-linux-gnu/6/include /usr/local/include /usr/lib/gcc/x86_64-linux-gnu/6/include-fixed /usr/include/x86_64-linux-gnu /usr/include End of search list. GNU C++14 (Debian 6.3.0-6) version 6.3.0 20170205 (x86_64-linux-gnu) compiled by GNU C version 6.3.0 20170205, GMP version 6.1.2, MPFR version 3.1.5, MPC version 1.0.3, isl version 0.15 GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: f4480661534e17ad26830674f037f8fe main.cpp: In function ‘int main()’: main.cpp:2:14: warning: ISO C++ forbids converting a string constant to ‘char*’ [-Wpedantic] char* str = "hello world!"; ^~~~~~~~~~~~~~ COLLECT_GCC_OPTIONS='-v' '-Wpedantic' '-Werror=write-strings' '-shared-libgcc' '-mtune=generic' '-march=x86-64' as -v --64 -o /tmp/ccE9VOo8.o /tmp/ccPbVEN2.s GNU assembler version 2.27.90 (x86_64-linux-gnu) using BFD version (GNU Binutils for Debian) 2.27.90.20170124 COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/6/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/6/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-Wpedantic' '-Werror=write-strings' '-shared-libgcc' '-mtune=generic' '-march=x86-64' /usr/lib/gcc/x86_64-linux-gnu/6/collect2 -plugin /usr/lib/gcc/x86_64-linux-gnu/6/liblto_plugin.so -plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/6/lto-wrapper -plugin-opt=-fresolution=/tmp/ccCfTe2d.res -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc --sysroot=/ --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu -dynamic-linker /lib64/ld-linux-x86-64.so.2 -pie /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/Scrt1.o /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/6/crtbeginS.o -L/usr/lib/gcc/x86_64-linux-gnu/6 -L/usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/6/../../../../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/6/../../.. /tmp/ccE9VOo8.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/6/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/crtn.o COLLECT_GCC_OPTIONS='-v' '-Wpedantic' '-Werror=write-strings' '-shared-libgcc' '-mtune=generic' '-march=x86-64' and an executable is produced. The behavior is unexpected, since I'm explicitly asking to treat this warning as an error. I do not wan't to remove "-Wpedantic" since it also enables other warnings.