diff options
Diffstat (limited to 'sid/sidplay-libs-2.1.0/libsidplay/unix/ac_compile_check_sizeof.m4')
| -rw-r--r-- | sid/sidplay-libs-2.1.0/libsidplay/unix/ac_compile_check_sizeof.m4 | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sid/sidplay-libs-2.1.0/libsidplay/unix/ac_compile_check_sizeof.m4 b/sid/sidplay-libs-2.1.0/libsidplay/unix/ac_compile_check_sizeof.m4 new file mode 100644 index 00000000..8ada30a5 --- /dev/null +++ b/sid/sidplay-libs-2.1.0/libsidplay/unix/ac_compile_check_sizeof.m4 @@ -0,0 +1,76 @@ +dnl @synopsis AC_COMPILE_CHECK_SIZEOF(TYPE [, HEADERS [, EXTRA_SIZES...]]) +dnl +dnl This macro checks for the size of TYPE using compile checks, not +dnl run checks. You can supply extra HEADERS to look into. the check +dnl will cycle through 1 2 4 8 16 and any EXTRA_SIZES the user +dnl supplies. If a match is found, it will #define SIZEOF_`TYPE' to +dnl that value. Otherwise it will emit a configure time error +dnl indicating the size of the type could not be determined. +dnl +dnl The trick is that C will not allow duplicate case labels. While +dnl this is valid C code: +dnl +dnl switch (0) case 0: case 1:; +dnl +dnl The following is not: +dnl +dnl switch (0) case 0: case 0:; +dnl +dnl Thus, the AC_TRY_COMPILE will fail if the currently tried size +dnl does not match. +dnl +dnl Here is an example skeleton configure.in script, demonstrating the +dnl macro's usage: +dnl +dnl AC_PROG_CC +dnl AC_CHECK_HEADERS(stddef.h unistd.h) +dnl AC_TYPE_SIZE_T +dnl AC_CHECK_TYPE(ssize_t, int) +dnl +dnl headers='#ifdef HAVE_STDDEF_H +dnl #include <stddef.h> +dnl #endif +dnl #ifdef HAVE_UNISTD_H +dnl #include <unistd.h> +dnl #endif +dnl ' +dnl +dnl AC_COMPILE_CHECK_SIZEOF(char) +dnl AC_COMPILE_CHECK_SIZEOF(short) +dnl AC_COMPILE_CHECK_SIZEOF(int) +dnl AC_COMPILE_CHECK_SIZEOF(long) +dnl AC_COMPILE_CHECK_SIZEOF(unsigned char *) +dnl AC_COMPILE_CHECK_SIZEOF(void *) +dnl AC_COMPILE_CHECK_SIZEOF(size_t, $headers) +dnl AC_COMPILE_CHECK_SIZEOF(ssize_t, $headers) +dnl AC_COMPILE_CHECK_SIZEOF(ptrdiff_t, $headers) +dnl AC_COMPILE_CHECK_SIZEOF(off_t, $headers) +dnl +dnl @author Kaveh Ghazi <ghazi@caip.rutgers.edu> +dnl @version $Id: ac_compile_check_sizeof.m4,v 1.1 2002/01/03 20:13:11 s_a_white Exp $ +dnl +AC_DEFUN([AC_COMPILE_CHECK_SIZEOF], +[changequote(<<, >>)dnl +dnl The name to #define. +define(<<AC_TYPE_NAME>>, translit(sizeof_$1, [a-z *], [A-Z_P]))dnl +dnl The cache variable name. +define(<<AC_CV_NAME>>, translit(ac_cv_sizeof_$1, [ *], [_p]))dnl +changequote([, ])dnl +AC_MSG_CHECKING(size of $1) +AC_CACHE_VAL(AC_CV_NAME, +[for ac_size in 4 8 1 2 16 $2 ; do # List sizes in rough order of prevalence. + AC_TRY_COMPILE([#include "confdefs.h" +#include <sys/types.h> +$2 +], [switch (0) case 0: case (sizeof ($1) == $ac_size):;], AC_CV_NAME=$ac_size) + if test x$AC_CV_NAME != x ; then break; fi +done +]) +if test x$AC_CV_NAME = x ; then + AC_MSG_ERROR([cannot determine a size for $1]) +fi +AC_MSG_RESULT($AC_CV_NAME) +AC_DEFINE_UNQUOTED(AC_TYPE_NAME, $AC_CV_NAME, [The number of bytes in type $1]) +undefine([AC_TYPE_NAME])dnl +undefine([AC_CV_NAME])dnl +]) |