Rework va_copy fallback

va_copy is a macro, so it can be detected without a feature test.
Fallback to __va_copy or memcpy.

CMakeLists.txt

@@ -157,19 +157,7 @@ if (NOT MSVC)
 	check_include_files(sys/timeb.h HAVE_SYS_TIMEB_H)
 	check_include_files(sys/time.h HAVE_SYS_TIME_H)
 	check_include_files(unistd.h HAVE_UNISTD_H)
-	check_symbol_exists(va_copy stdarg.h HAVE_VA_COPY)
-	check_symbol_exists(__va_copy stdarg.h HAVE___VA_COPY)
 	set(LT_OBJDIR ".libs/")
-	check_c_source_compiles("
-		#include <stdarg.h>
-		void a(va_list* ap) {};
-		int main() { va_list ap1, ap2; a(&ap1); ap2 = (va_list) ap1; return 0; }
-	" VA_LIST_IS_ARRAY_TEST)
-	if(VA_LIST_IS_ARRAY_TEST)
-		set(VA_LIST_IS_ARRAY FALSE)
-	else()
-		set(VA_LIST_IS_ARRAY TRUE)
-	endif()
 	check_c_source_compiles("
 		#include <stddef.h>
 		#include <sys/socket.h>

config.h.cmake.in

@@ -90,15 +90,9 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #cmakedefine HAVE_UNISTD_H 1
 
-/* Whether va_copy() is available */
-#cmakedefine HAVE_VA_COPY 1
-
 /* Define to 1 if you have the <zlib.h> header file. */
 #cmakedefine HAVE_ZLIB_H 1
 
-/* Whether __va_copy() is available */
-#cmakedefine HAVE___VA_COPY 1
-
 /* Define to the sub-directory where libtool stores uninstalled libraries. */
 #cmakedefine LT_OBJDIR "@LT_OBJDIR@"
 
@@ -126,9 +120,6 @@
 /* Support for IPv6 */
 #cmakedefine SUPPORT_IP6 1
 
-/* Define if va_list is an array type */
-#cmakedefine VA_LIST_IS_ARRAY 1
-
 /* Version number of package */
 #cmakedefine VERSION "@VERSION@"
 

configure.ac

@@ -317,37 +317,6 @@ AH_VERBATIM([HAVE_MUNMAP_AFTER],[/* mmap() is no good without munmap() */
 #  undef /**/ HAVE_MMAP
 #endif])
 
-dnl Checking for va_copy availability
-AC_MSG_CHECKING([for va_copy])
-AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdarg.h>
-va_list ap1,ap2;]], [[va_copy(ap1,ap2);]])],
-have_va_copy=yes,
-have_va_copy=no)
-AC_MSG_RESULT($have_va_copy)
-if test x"$have_va_copy" = x"yes"; then
-    AC_DEFINE(HAVE_VA_COPY,1,[Whether va_copy() is available])
-else
-    AC_MSG_CHECKING([for __va_copy])
-    AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdarg.h>
-    va_list ap1,ap2;]], [[__va_copy(ap1,ap2);]])],
-    have___va_copy=yes,
-    have___va_copy=no)
-    AC_MSG_RESULT($have___va_copy)
-    if test x"$have___va_copy" = x"yes"; then
-        AC_DEFINE(HAVE___VA_COPY,1,[Whether __va_copy() is available])
-    fi
-fi
-
-dnl Checking whether va_list is an array type
-AC_MSG_CHECKING([whether va_list is an array type])
-AC_TRY_COMPILE2([
-#include <stdarg.h>
-void a(va_list * ap) {}],[
-va_list ap1, ap2; a(&ap1); ap2 = (va_list) ap1],[
-  AC_MSG_RESULT(no)],[
-  AC_MSG_RESULT(yes)
-  AC_DEFINE([VA_LIST_IS_ARRAY], [1],[Define if va_list is an array type])])
-
 dnl
 dnl Checks for inet libraries
 dnl

xmlreader.c

@@ -54,26 +54,11 @@
 #define MAX_FREE_NODES 100
 #endif
 
-/*
+#ifndef va_copy
- * The following VA_COPY was coded following an example in
+  #ifdef __va_copy
- * the Samba project.  It may not be sufficient for some
+    #define va_copy(dest, src) __va_copy(dest, src)
- * esoteric implementations of va_list but (hopefully) will
- * be sufficient for libxml2.
- */
-#ifndef VA_COPY
-  #ifdef HAVE_VA_COPY
-    #define VA_COPY(dest, src) va_copy(dest, src)
   #else
-    #ifdef HAVE___VA_COPY
+    #define va_copy(dest, src) memcpy(dest, src, sizeof(va_list))
-      #define VA_COPY(dest,src) __va_copy(dest, src)
-    #else
-      #ifndef VA_LIST_IS_ARRAY
-        #define VA_COPY(dest,src) (dest) = (src)
-      #else
-        #include <string.h>
-        #define VA_COPY(dest,src) memcpy((char *)(dest),(char *)(src),sizeof(va_list))
-      #endif
-    #endif
   #endif
 #endif
 
@@ -4590,7 +4575,7 @@ xmlTextReaderBuildMessage(const char *msg, va_list ap) {
     va_list aq;
 
     while (1) {
-        VA_COPY(aq, ap);
+        va_copy(aq, ap);
         chars = vsnprintf(str, size, msg, aq);
         va_end(aq);
         if (chars < 0) {

xmlwriter.c

@@ -11,6 +11,7 @@
 #define IN_LIBXML
 #include "libxml.h"
 #include <string.h>
+#include <stdarg.h>
 
 #include <libxml/xmlmemory.h>
 #include <libxml/parser.h>
@@ -30,26 +31,11 @@
 #define B64LINELEN 72
 #define B64CRLF "\r\n"
 
-/*
+#ifndef va_copy
- * The following VA_COPY was coded following an example in
+  #ifdef __va_copy
- * the Samba project.  It may not be sufficient for some
+    #define va_copy(dest, src) __va_copy(dest, src)
- * esoteric implementations of va_list but (hopefully) will
- * be sufficient for libxml2.
- */
-#ifndef VA_COPY
-  #ifdef HAVE_VA_COPY
-    #define VA_COPY(dest, src) va_copy(dest, src)
   #else
-    #ifdef HAVE___VA_COPY
+    #define va_copy(dest, src) memcpy(dest, src, sizeof(va_list))
-      #define VA_COPY(dest,src) __va_copy(dest, src)
-    #else
-      #ifndef VA_LIST_IS_ARRAY
-        #define VA_COPY(dest,src) (dest) = (src)
-      #else
-        #include <string.h>
-        #define VA_COPY(dest,src) memcpy((char *)(dest),(char *)(src),sizeof(va_list))
-      #endif
-    #endif
   #endif
 #endif
 
@@ -4486,7 +4472,7 @@ xmlTextWriterVSprintf(const char *format, va_list argptr)
         return NULL;
     }
 
-    VA_COPY(locarg, argptr);
+    va_copy(locarg, argptr);
     while (((count = vsnprintf((char *) buf, size, format, locarg)) < 0)
            || (count == size - 1) || (count == size) || (count > size)) {
 	va_end(locarg);
@@ -4498,7 +4484,7 @@ xmlTextWriterVSprintf(const char *format, va_list argptr)
                             "xmlTextWriterVSprintf : out of memory!\n");
             return NULL;
         }
-	VA_COPY(locarg, argptr);
+	va_copy(locarg, argptr);
     }
     va_end(locarg);