diff options
Diffstat (limited to 'tools/missing-macros/src/m4/va_copy.m4')
| -rw-r--r-- | tools/missing-macros/src/m4/va_copy.m4 | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/tools/missing-macros/src/m4/va_copy.m4 b/tools/missing-macros/src/m4/va_copy.m4 new file mode 100644 index 000000000..0e88ee662 --- /dev/null +++ b/tools/missing-macros/src/m4/va_copy.m4 @@ -0,0 +1,111 @@ +# va_copy.m4 serial 1 (js-1.6.20070208) + +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 +]) + |