1 files changed, 76 insertions, 0 deletions
diff --git a/m4/stdarg.m4 b/m4/stdarg.m4
new file mode 100644
index 0000000..eafa86c
--- /dev/null
+++ b/m4/stdarg.m4
@@ -0,0 +1,76 @@
+# stdarg.m4 serial 8
+dnl Copyright (C) 2006, 2008-2022 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+dnl Provide a working va_copy in combination with <stdarg.h>.
+
+AC_DEFUN([gl_STDARG_H],
+[
+  GL_GENERATE_STDARG_H=false
+  NEXT_STDARG_H='<stdarg.h>'
+  AC_CACHE_CHECK([for va_copy],
+    [gl_cv_func_va_copy],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stdarg.h>]],
+          [[
+#ifndef va_copy
+void (*func) (va_list, va_list) = va_copy;
+#endif
+          ]])],
+       [gl_cv_func_va_copy=yes],
+       [gl_cv_func_va_copy=no])
+    ])
+  if test $gl_cv_func_va_copy = no; then
+    dnl Provide a substitute.
+    dnl Usually a simple definition in <config.h> is enough. Not so on AIX 5
+    dnl with some versions of the /usr/vac/bin/cc compiler. It has an <stdarg.h>
+    dnl which does '#undef va_copy', leading to a missing va_copy symbol. For
+    dnl this platform, we use an <stdarg.h> substitute. But we cannot use this
+    dnl approach on other platforms, because <stdarg.h> often defines only
+    dnl preprocessor macros and gl_ABSOLUTE_HEADER, gl_CHECK_NEXT_HEADERS do
+    dnl not work in this situation.
+    AC_EGREP_CPP([vaccine],
+      [#if defined _AIX && !defined __GNUC__
+        AIX vaccine
+       #endif
+      ], [gl_aixcc=yes], [gl_aixcc=no])
+    if test $gl_aixcc = yes; then
+      dnl Provide a substitute <stdarg.h> file.
+      GL_GENERATE_STDARG_H=true
+      gl_NEXT_HEADERS([stdarg.h])
+      dnl Fallback for the case when <stdarg.h> contains only macro definitions.
+      if test "$gl_cv_next_stdarg_h" = '""'; then
+        gl_cv_next_stdarg_h='"///usr/include/stdarg.h"'
+        NEXT_STDARG_H="$gl_cv_next_stdarg_h"
+      fi
+    else
+      dnl Provide a substitute in <config.h>, either __va_copy or as a simple
+      dnl assignment.
+      gl_CACHE_VAL_SILENT([gl_cv_func___va_copy], [
+        AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM(
+             [[#include <stdarg.h>]],
+             [[
+#ifndef __va_copy
+error, bail out
+#endif
+             ]])],
+          [gl_cv_func___va_copy=yes],
+          [gl_cv_func___va_copy=no])])
+      if test $gl_cv_func___va_copy = yes; then
+        AC_DEFINE([va_copy], [__va_copy],
+          [Define as a macro for copying va_list variables.])
+      else
+        AH_VERBATIM([gl_VA_COPY], [/* A replacement for va_copy, if needed.  */
+#define gl_va_copy(a,b) ((a) = (b))])
+        AC_DEFINE([va_copy], [gl_va_copy],
+          [Define as a macro for copying va_list variables.])
+      fi
+    fi
+  fi
+  AC_SUBST([NEXT_STDARG_H])
+])