I've upgraded to the latest mingw.org's MinGW runtime lately, and that triggers compilation errors building GDB 7.12: g++ -O2 -gdwarf-4 -g3 -I. -I. -I./common -I./config -DLOCALEDIR="\"d:/usr/share/locale\"" -DHAVE_CONFIG_H -I./../include/opcode -I./../opcodes/.. -I./../readline/.. -I../bfd -I./../bfd -I./../include -I../libdecnumber -I./../libdecnumber -I./gnulib/import -Ibuildgnulib/import -DTUI=1 -Id:/usr/include -Id:/usr/include/guile/2.0 -Id:/usr/Python26/include -Id:/usr/Python26/include -Wall -Wpointer-arith -Wno-unused -Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts -Wempty-body -Wunused-but-set-parameter -Wunused-but-set-variable -Wno-signcompare -Wno-write-strings -Wno-narrowing -Wno-format -c -o windows-nat.o -MT windows-nat.o -MMD -MP -MF .deps/windows-nat.Tpo windowsnat.c windows-nat.c: In function 'so_list* windows_make_so(const char*, LPVOID)': windows-nat.c:608:35: error: 'strcasecmp' was not declared in this scope if (strcasecmp (buf, "ntdll.dll") == 0) ^ windows-nat.c: In function 'int envvar_cmp(const void*, const void*)': windows-nat.c:2031:28: error: 'strcasecmp' was not declared in this scope return strcasecmp (*p, *q); ^ Makefile:1134: recipe for target `windows-nat.o' failed make[2]: *** [windows-nat.o] Error 1 A similar error happens in stap-probe.c. The reason for this is that MinGW runtime changed the place where the prototypes of strcasecmp and strncasecmp are declared: they are now in strings.h (which AFAIU is more compatible to other systems). But we don't include strings.h anywhere, although the configure script probes for it. I guess other platforms include that header indirectly somehow.
Fixed in GDB 7.12.1.
The patch was approved in https://sourceware.org/ml/gdb-patches/2016-10/msg00329.html