Index: acinclude.m4 =================================================================== --- acinclude.m4 (revision 130038) +++ acinclude.m4 (working copy) @@ -763,9 +763,13 @@ AC_LANG_SAVE AC_LANG_CPLUSPLUS - # Use -fno-exceptions so that the C driver can link these tests without - # hitting undefined references to personality routines. + # Use -std=c++98 because the default (-std=gnu++98) leaves __STRICT_ANSI__ + # undefined and fake C99 facilities - like pre-standard snprintf - may be + # spuriously enabled. + # Long term, -std=c++0x could be even better, could manage to explicitely + # request C99 facilities to the underlying C headers. ac_save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS -std=c++98" ac_save_LIBS="$LIBS" ac_save_gcc_no_link="$gcc_no_link" @@ -996,6 +1000,11 @@ AC_LANG_SAVE AC_LANG_CPLUSPLUS + # Use -std=c++98 because the default (-std=gnu++98) leaves __STRICT_ANSI__ + # undefined and fake C99 facilities may be spuriously enabled. + ac_save_CXXFLAGS="$CXXFLAGS" + CXXFLAGS="$CXXFLAGS -std=c++98" + # Check for the existence of complex math functions used # by tr1/complex. AC_CHECK_HEADERS(complex.h, ac_has_complex_h=yes, ac_has_complex_h=no) @@ -1266,6 +1275,7 @@ # Check for the existence of the header. AC_CHECK_HEADERS(stdbool.h) + CXXFLAGS="$ac_save_CXXFLAGS" AC_LANG_RESTORE ])