Package: autoconf
Version: 2.69-11
Severity: serious
Originally debugged by Amos Jeffries in #907106:
$ cat configure.ac
AC_INIT
AC_PROG_CXX
AC_LANG([C++])
AC_SEARCH_LIBS([__atomic_load_8],[atomic])
$ autoconf
$ CXX=g++-7 ./configure
checking whether the C++ compiler works... yes
checking for C++ compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C++ compiler... yes
checking whether g++-7 accepts -g... yes
checking for library containing __atomic_load_8... -latomic
$ CXX=g++-8 ./configure
checking whether the C++ compiler works... yes
checking for C++ compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C++ compiler... yes
checking whether g++-8 accepts -g... yes
checking for library containing __atomic_load_8... no
$
config.log says:
...
| #ifdef __cplusplus
| extern "C"
| #endif
| char __atomic_load_8 ();
| int
| main ()
| {
| return __atomic_load_8 ();
| ;
| return 0;
| }
configure:2326: g++-8 -o conftest -g -O2 conftest.cpp -latomic >&5
conftest.cpp:16:6: error: new declaration 'char __atomic_load_8()' ambiguates
built-in declaration 'long unsigned int __atomic_load_8(const volatile void*,
int)' [-fpermissive]
char __atomic_load_8 ();
^~~~~~~~~~~~~~~
conftest.cpp: In function 'int main()':
conftest.cpp:20:25: error: too few arguments to function 'long unsigned int
__atomic_load_8(const volatile void*, int)'
return __atomic_load_8 ();
^
...
