Document va_copy in preference to __va_copy.

2 files changed, 16 insertions, 14 deletions

diff --git a/manual/lang.texi b/manual/lang.texi
index baaccaa30f..ee04e233a9 100644
--- a/manual/lang.texi
+++ b/manual/lang.texi
@@ -463,28 +463,33 @@ assign the value of one variable of type @code{va_list} to another variable
 of the same type.
 
 @comment stdarg.h
-@comment GNU
-@deftypefn {Macro} void __va_copy (va_list @var{dest}, va_list @var{src})
-The @code{__va_copy} macro allows copying of objects of type
+@comment ISO
+@deftypefn {Macro} void va_copy (va_list @var{dest}, va_list @var{src})
+@deftypefnx {Macro} void __va_copy (va_list @var{dest}, va_list @var{src})
+The @code{va_copy} macro allows copying of objects of type
 @code{va_list} even if this is not an integral type.  The argument pointer
 in @var{dest} is initialized to point to the same argument as the
 pointer in @var{src}.
 
-This macro is a GNU extension but it will hopefully also be available in
-the next update of the ISO C standard.
+This macro was added in ISO C99.  When building for strict conformance
+to ISO C90 (@samp{gcc -ansi}), it is not available.  The macro
+@code{__va_copy} is available as a GNU extension in any standards
+mode; before GCC 3.0, it was the only macro for this functionality.
 @end deftypefn
 
-If you want to use @code{__va_copy} you should always be prepared for the
+If you want to use @code{va_copy} and be portable to pre-C99 systems,
+you should always be prepared for the
 possibility that this macro will not be available.  On architectures where a
-simple assignment is invalid, hopefully @code{__va_copy} @emph{will} be available,
-so one should always write something like this:
+simple assignment is invalid, hopefully @code{va_copy} @emph{will} be available,
+so one should always write something like this if concerned about
+pre-C99 portability:
 
 @smallexample
 @{
   va_list ap, save;
   @dots{}
-#ifdef __va_copy
-  __va_copy (save, ap);
+#ifdef va_copy
+  va_copy (save, ap);
 #else
   save = ap;
 #endif
diff --git a/manual/string.texi b/manual/string.texi
index 831873b126..2844bc61e5 100644
--- a/manual/string.texi
+++ b/manual/string.texi
@@ -824,7 +824,6 @@ to use @code{strcat}/@code{wcscat}.  A lot of time is wasted finding the
 end of the destination string so that the actual copying can start.
 This is a common example:
 
-@cindex __va_copy
 @cindex va_copy
 @smallexample
 /* @r{This function concatenates arbitrarily many strings.  The last}
@@ -838,9 +837,7 @@ concat (const char *str, @dots{})
   char *result;
 
   va_start (ap, str);
-  /* @r{Actually @code{va_copy}, but this is the name more gcc versions}
-     @r{understand.}  */
-  __va_copy (ap2, ap);
+  va_copy (ap2, ap);
 
   /* @r{Determine how much space we need.}  */
   for (s = str; s != NULL; s = va_arg (ap, const char *))