https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90860
Bug ID: 90860
Summary: Static const variable initialized with another static
const compiles
Product: gcc
Version: 8.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: mateusz+gcc at argc dot pl
Target Milestone: ---
static const int one = 1;
static const int two = one;
int main()
{
return two;
}
Following code does not compile on gcc 7.4, yet it does on gcc 8.3. I looked
into the C11 standard and it still does not consider static const variable a
constant expression, so it should not be allowed to initialize one static const
with another. Am I missing something? Is it a GNU extension? Clang compiles it
as well so I'm not sure now.
======================
#
# GCC 7.4
#
root@690b42b21d92:/# gcc-7 -v -save-temps -Wall -Wextra -pedantic -std=c11
test.c
Using built-in specs.
COLLECT_GCC=gcc-7
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='Debian 7.4.0-6'
--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 --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-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 7.4.0 (Debian 7.4.0-6)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/7/cc1 -E -quiet -v -imultiarch x86_64-linux-gnu
test.c -mtune=generic -march=x86-64 -std=c11 -Wall -Wextra -Wpedantic
-fpch-preprocess -o test.i
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/7/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-linux-gnu/7/include
/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu/7/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/7/cc1 -fpreprocessed test.i -quiet -dumpbase
test.c -mtune=generic -march=x86-64 -auxbase test -Wall -Wextra -Wpedantic
-std=c11 -version -o test.s
GNU C11 (Debian 7.4.0-6) version 7.4.0 (x86_64-linux-gnu)
compiled by GNU C version 7.4.0, GMP version 6.1.2, MPFR version 4.0.2,
MPC version 1.1.0, isl version isl-0.20-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C11 (Debian 7.4.0-6) version 7.4.0 (x86_64-linux-gnu)
compiled by GNU C version 7.4.0, GMP version 6.1.2, MPFR version 4.0.2,
MPC version 1.1.0, isl version isl-0.20-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: dabcd01bdc94175b108270865f841639
test.c:2:24: error: initializer element is not constant
static const int two = one;
^~~
======================
#
# GCC 8.3
#
root@690b42b21d92:/# gcc -v -save-temps -Wall -Wextra -pedantic -std=c11 test.c
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 8.3.0-6'
--with-bugurl=file:///usr/share/doc/gcc-8/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++ --prefix=/usr
--with-gcc-major-version-only --program-suffix=-8
--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-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 8.3.0 (Debian 8.3.0-6)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/8/cc1 -E -quiet -v -imultiarch x86_64-linux-gnu
test.c -mtune=generic -march=x86-64 -std=c11 -Wall -Wextra -Wpedantic
-fpch-preprocess -o test.i
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-linux-gnu/8/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-linux-gnu/8/include
/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu/8/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/8/cc1 -fpreprocessed test.i -quiet -dumpbase
test.c -mtune=generic -march=x86-64 -auxbase test -Wall -Wextra -Wpedantic
-std=c11 -version -o test.s
GNU C11 (Debian 8.3.0-6) version 8.3.0 (x86_64-linux-gnu)
compiled by GNU C version 8.3.0, GMP version 6.1.2, MPFR version 4.0.2,
MPC version 1.1.0, isl version isl-0.20-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C11 (Debian 8.3.0-6) version 8.3.0 (x86_64-linux-gnu)
compiled by GNU C version 8.3.0, GMP version 6.1.2, MPFR version 4.0.2,
MPC version 1.1.0, isl version isl-0.20-GMP
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 694977f912fd7ca2c14d66a7306be21c
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
as -v --64 -o test.o test.s
GNU assembler version 2.31.1 (x86_64-linux-gnu) using BFD version (GNU Binutils
for Debian) 2.31.1
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/8/:/usr/lib/gcc/x86_64-linux-gnu/8/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/8/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/8/:/usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/8/../../../../lib/:/lib/x86_64-linux-gnu/:/lib/../lib/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/8/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/8/collect2 -plugin
/usr/lib/gcc/x86_64-linux-gnu/8/liblto_plugin.so
-plugin-opt=/usr/lib/gcc/x86_64-linux-gnu/8/lto-wrapper
-plugin-opt=-fresolution=test.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 --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/8/../../../x86_64-linux-gnu/Scrt1.o
/usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crti.o
/usr/lib/gcc/x86_64-linux-gnu/8/crtbeginS.o -L/usr/lib/gcc/x86_64-linux-gnu/8
-L/usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu
-L/usr/lib/gcc/x86_64-linux-gnu/8/../../../../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/8/../../.. test.o -lgcc --push-state
--as-needed -lgcc_s --pop-state -lc -lgcc --push-state --as-needed -lgcc_s
--pop-state /usr/lib/gcc/x86_64-linux-gnu/8/crtendS.o
/usr/lib/gcc/x86_64-linux-gnu/8/../../../x86_64-linux-gnu/crtn.o
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-Wextra' '-Wpedantic'
'-std=c11' '-mtune=generic' '-march=x86-64'
# no error
