You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
3.6 KiB
Plaintext
110 lines
3.6 KiB
Plaintext
dnl ##
|
|
dnl ## Check for C99 va_copy() implementation
|
|
dnl ## (and provide fallback implementation if neccessary)
|
|
dnl ##
|
|
dnl ## configure.in:
|
|
dnl ## AC_CHECK_VA_COPY
|
|
dnl ## foo.c:
|
|
dnl ## #include "config.h"
|
|
dnl ## [...]
|
|
dnl ## va_copy(d,s)
|
|
dnl ##
|
|
dnl ## This check is rather complex: first because we really have to
|
|
dnl ## try various possible implementations in sequence and second, we
|
|
dnl ## cannot define a macro in config.h with parameters directly.
|
|
dnl ##
|
|
|
|
dnl # test program for va_copy() implementation
|
|
changequote(<<,>>)
|
|
m4_define(__va_copy_test, <<[
|
|
#include <stdlib.h>
|
|
#include <stdarg.h>
|
|
#include <string.h>
|
|
#define DO_VA_COPY(d, s) $1
|
|
void test(char *str, ...)
|
|
{
|
|
va_list ap, ap2;
|
|
int i;
|
|
va_start(ap, str);
|
|
DO_VA_COPY(ap2, ap);
|
|
for (i = 1; i <= 9; i++) {
|
|
int k = (int)va_arg(ap, int);
|
|
if (k != i)
|
|
abort();
|
|
}
|
|
DO_VA_COPY(ap, ap2);
|
|
for (i = 1; i <= 9; i++) {
|
|
int k = (int)va_arg(ap, int);
|
|
if (k != i)
|
|
abort();
|
|
}
|
|
va_end(ap);
|
|
}
|
|
int main(int argc, char *argv[])
|
|
{
|
|
test("test", 1, 2, 3, 4, 5, 6, 7, 8, 9);
|
|
exit(0);
|
|
}
|
|
]>>)
|
|
changequote([,])
|
|
|
|
dnl # test driver for va_copy() implementation
|
|
m4_define(__va_copy_check, [
|
|
AH_VERBATIM($1,
|
|
[/* Predefined possible va_copy() implementation (id: $1) */
|
|
#define __VA_COPY_USE_$1(d, s) $2])
|
|
if test ".$ac_cv_va_copy" = .; then
|
|
AC_TRY_RUN(__va_copy_test($2), [ac_cv_va_copy="$1"])
|
|
fi
|
|
])
|
|
|
|
dnl # Autoconf check for va_copy() implementation checking
|
|
AC_DEFUN([AC_CHECK_VA_COPY],[
|
|
dnl # provide Autoconf display check message
|
|
AC_MSG_CHECKING(for va_copy() function)
|
|
dnl # check for various implementations in priorized sequence
|
|
AC_CACHE_VAL(ac_cv_va_copy, [
|
|
ac_cv_va_copy=""
|
|
dnl # 1. check for standardized C99 macro
|
|
__va_copy_check(C99, [va_copy((d), (s))])
|
|
dnl # 2. check for alternative/deprecated GCC macro
|
|
__va_copy_check(GCM, [VA_COPY((d), (s))])
|
|
dnl # 3. check for internal GCC macro (high-level define)
|
|
__va_copy_check(GCH, [__va_copy((d), (s))])
|
|
dnl # 4. check for internal GCC macro (built-in function)
|
|
__va_copy_check(GCB, [__builtin_va_copy((d), (s))])
|
|
dnl # 5. check for assignment approach (assuming va_list is a struct)
|
|
__va_copy_check(ASS, [do { (d) = (s); } while (0)])
|
|
dnl # 6. check for assignment approach (assuming va_list is a pointer)
|
|
__va_copy_check(ASP, [do { *(d) = *(s); } while (0)])
|
|
dnl # 7. check for memory copying approach (assuming va_list is a struct)
|
|
__va_copy_check(CPS, [memcpy((void *)&(d), (void *)&(s)), sizeof((s))])
|
|
dnl # 8. check for memory copying approach (assuming va_list is a pointer)
|
|
__va_copy_check(CPP, [memcpy((void *)(d), (void *)(s)), sizeof(*(s))])
|
|
if test ".$ac_cv_va_copy" = .; then
|
|
AC_ERROR([no working implementation found])
|
|
fi
|
|
])
|
|
dnl # optionally activate the fallback implementation
|
|
if test ".$ac_cv_va_copy" = ".C99"; then
|
|
AC_DEFINE(HAVE_VA_COPY, 1, [Define if va_copy() macro exists (and no fallback implementation is required)])
|
|
fi
|
|
dnl # declare which fallback implementation to actually use
|
|
AC_DEFINE_UNQUOTED([__VA_COPY_USE], [__VA_COPY_USE_$ac_cv_va_copy],
|
|
[Define to id of used va_copy() implementation])
|
|
dnl # provide activation hook for fallback implementation
|
|
AH_VERBATIM([__VA_COPY_ACTIVATION],
|
|
[/* Optional va_copy() implementation activation */
|
|
#ifndef HAVE_VA_COPY
|
|
#define va_copy(d, s) __VA_COPY_USE(d, s)
|
|
#endif
|
|
])
|
|
dnl # provide Autoconf display result message
|
|
if test ".$ac_cv_va_copy" = ".C99"; then
|
|
AC_MSG_RESULT([yes])
|
|
else
|
|
AC_MSG_RESULT([no (using fallback implementation)])
|
|
fi
|
|
])
|
|
|