https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66976
Bug ID: 66976
Summary: Compiler error for well-formed program with a
definition of a constexpr function returning void
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: anders.granlund.0 at gmail dot com
Target Milestone: ---
The following program (prog.cc in the command line below) is well-formed:
constexpr void f() {}
int main() {}
Note that the return type void is a literal type according to [basic.types]/10:
http://eel.is/c++draft/basic.types#10
I compiled the program with the following command line:
gcc prog.cc -std=c++11 -pedantic-errors
I expected to get no errors since the program is well-formed, but I got the
following error:
prog.cc: In function 'constexpr void f()':
prog.cc:1:16: error: invalid return type 'void' of constexpr function
'constexpr void f()'constexpr void f() {}
^
For comparison Clang accepts the program without errors.
Output for gcc -v (I think the bug quite independent of this however):
Using built-in specs.
COLLECT_GCC=/usr/local/gcc-head/bin/g++
COLLECT_LTO_WRAPPER=/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: /home/heads/gcc/gcc-source/configure
--prefix=/usr/local/gcc-head --enable-languages=c,c++ --enable-lto
--disable-multilib --without-ppl --without-cloog-ppl --enable-checking=release
--disable-nls
Thread model: posix
gcc version 6.0.0 20150722 (experimental) (GCC)
COLLECT_GCC_OPTIONS='-o' 'prog.exe' '-std=c++11' '-pedantic-errors' '-v'
'-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/cc1plus -quiet
-v -imultiarch x86_64-linux-gnu -D_GNU_SOURCE prog.cc -quiet -dumpbase prog.cc
-mtune=generic -march=x86-64 -auxbase prog -pedantic-errors -std=c++11 -version
-o /tmp/ccE6wwKW.s
GNU C++11 (GCC) version 6.0.0 20150722 (experimental)
(x86_64-unknown-linux-gnu)
compiled by GNU C version 6.0.0 20150722 (experimental), GMP version
5.1.2, MPFR version 3.1.2, MPC version 1.0.1
warning: GMP header version 5.1.2 differs from library version 5.0.2.
warning: MPFR header version 3.1.2 differs from library version 3.1.0-p3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory
"/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../../x86_64-unknown-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../../include/c++/6.0.0
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../../include/c++/6.0.0/x86_64-unknown-linux-gnu
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../../include/c++/6.0.0/backward
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/include
/usr/local/include
/usr/local/gcc-head/include
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/include-fixed
/usr/include/x86_64-linux-gnu
/usr/include
End of search list.
GNU C++11 (GCC) version 6.0.0 20150722 (experimental)
(x86_64-unknown-linux-gnu)
compiled by GNU C version 6.0.0 20150722 (experimental), GMP version
5.1.2, MPFR version 3.1.2, MPC version 1.0.1
warning: GMP header version 5.1.2 differs from library version 5.0.2.
warning: MPFR header version 3.1.2 differs from library version 3.1.0-p3.
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 9115218d8690e08d2bbd8844106c0d12
COLLECT_GCC_OPTIONS='-o' 'prog.exe' '-std=c++11' '-pedantic-errors' '-v'
'-shared-libgcc' '-mtune=generic' '-march=x86-64'
as -v --64 -o /tmp/cc8TSYhs.o /tmp/ccE6wwKW.s
GNU assembler version 2.22 (x86_64-linux-gnu) using BFD version (GNU Binutils
for Ubuntu) 2.22
COMPILER_PATH=/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/:/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/:/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/:/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/:/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/
LIBRARY_PATH=/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/:/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../../lib64/:/lib/x86_64-linux-gnu/:/lib/../lib64/:/usr/lib/x86_64-linux-gnu/:/usr/lib/../lib64/:/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-o' 'prog.exe' '-std=c++11' '-pedantic-errors' '-v'
'-shared-libgcc' '-mtune=generic' '-march=x86-64'
/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/collect2
-plugin
/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/liblto_plugin.so
-plugin-opt=/usr/local/gcc-head/libexec/gcc/x86_64-unknown-linux-gnu/6.0.0/lto-wrapper
-plugin-opt=-fresolution=/tmp/cc4yk1QX.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
--eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o
prog.exe /usr/lib/x86_64-linux-gnu/crt1.o /usr/lib/x86_64-linux-gnu/crti.o
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/crtbegin.o
-L/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0
-L/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../../../lib64
-L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu
-L/usr/lib/../lib64
-L/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/../../.. -rpath
/usr/local/gcc-head/lib64 -lpthread /tmp/cc8TSYhs.o -lstdc++ -lm -lgcc_s -lgcc
-lc -lgcc_s -lgcc
/usr/local/gcc-head/lib/gcc/x86_64-unknown-linux-gnu/6.0.0/crtend.o
/usr/lib/x86_64-linux-gnu/crtn.o
