ccbugcast.m4

来自「Cracker终结者——提供最优秀的软件保护技术」· M4 代码 · 共 24 行

## --------------------------------------------------------- ##
## Checking if compiler correctly cast signed to unsigned.   ##
## Adapted from zsh.                                         ##
## --------------------------------------------------------- ##

# serial 1

AC_DEFUN(mfx_PROG_CC_BUG_SIGNED_TO_UNSIGNED_CASTING,
[AC_REQUIRE([AC_PROG_CC])dnl
AC_REQUIRE([AC_PROG_CPP])dnl
AC_CACHE_CHECK([whether signed to unsigned casting is broken],
mfx_cv_prog_cc_bug_signed_to_unsigned_casting,
[AC_TRY_COMPILE([], [#undef SIGNED
#if defined(__STDC__) || defined(__cplusplus)
#define SIGNED signed
#else
#define SIGNED
#endif
char x[1 - 2 * ( (int)((unsigned char)((SIGNED char) -1)) != 255 )];
],
mfx_cv_prog_cc_bug_signed_to_unsigned_casting=no,
mfx_cv_prog_cc_bug_signed_to_unsigned_casting=yes)])
])