When compiling GDB 7.8.1, I get this warning in libiberty: gcc -c -DHAVE_CONFIG_H -O0 -g3 -D__USE_MINGW_ACCESS -I. -I./../include -W -Wall -Wwrite-strings -Wc++-compat -Wstrict-prototypes -pedantic ./strerror.c -o strerror.o ./strerror.c:472:12: warning: '_sys_nerr' redeclared without dllimport attribute: previous dllimport ignored [-Wattributes] ./strerror.c:473:14: warning: '_sys_errlist' redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]
This happens because the MinGW system headers have some special magic for these variables, which are imported from a system shared library. The solution I propose is to refrain from declaring variables that are actually macros, because this should be a sign that something tricky is going on: --- libiberty/strerror.c~0 2014-06-11 18:34:41 +0300 +++ libiberty/strerror.c 2014-12-30 08:12:00 +0200 @@ -469,8 +469,13 @@ #else + +#ifndef sys_nerr extern int sys_nerr; +#endif +#ifndef sys_errlist extern char *sys_errlist[]; +#endif #endif OK to commit this (with a suitable ChangeLog entry)?