On Fri, Jul 19, 2013 at 5:27 AM, Patrick Begou <Patrick.Begou@xxxxxxxxxxxxxxxxxxxx> wrote: > > I get a strange problem with g++ 4.8. My server has gcc44-c++-4.4.1 > installed. > I've installed gcc4.8 in my home from gcc-4.8-20130711.tar.gz > gcc-4.8-infrastructure.tar.gz. > PATH, LD_LIBRARY_PATH are setup to reach first this 4.8 install. > > Initially I get the error runing the configure script to build OpenMPI, so I > extract the small peace of test code in "prog.C" file for testing and: > > g++ -o conftest -DNDEBUG -finline-functions prog.C > Is working but: > g++ -o conftest -O3 -DNDEBUG -finline-functions prog.C > says: > > In file included from /usr/include/stdio.h:909:0, > from prog.C:141: > /usr/include/bits/stdio.h: In function ‘__ssize_t getline(char**, size_t*, > FILE*)’: > /usr/include/bits/stdio.h:118:52: error: ‘__getdelim’ was not declared in > this scope > return __getdelim (__lineptr, __n, '\n', __stream); > > Same behavior with -O2 or -O1. > g++ 4.8 works with -O0. > > I've no idea about this problem. Thanks for your advices. Using optimization changes how your library header files behave. Look for #ifdef __OPTIMIZE__ or defined(__OPTIMIZE__). This looks like a problem with your C library, not with GCC proper. Ian
