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.
