re PR target/35054 (No documentation of #pragma push_macro("macro_name"))

	PR 35054
	* doc/extend.texi (Structure-Packing Pragmas): Replace "Win32"
	with the phrase "Microsoft Windows compilers".
	(Push/Pop Macro Pragmas): New subsection. Document
	#pragma push_macro and pragma pop_macro.

From-SVN: r133161

gcc/ChangeLog

+2008-03-13  Danny Smith  <dannysmith@users.sourceforge.net>
+
+	PR 35054
+	* doc/extend.texi (Structure-Packing Pragmas): Replace "Win32"
+	with the phrase "Microsoft Windows compilers".
+	(Push/Pop Macro Pragmas): New subsection. Document
+	#pragma push_macro and pragma pop_macro.
+
 2008-03-12  Paul Brook  <paul@codesourcery.com>
 
 	* config/arm/arm.c (output_move_double): Prefer LDRD to LDM.

gcc/doc/extend.texi

@@ -10868,6 +10868,7 @@ for further explanation.
 * Weak Pragmas::
 * Diagnostic Pragmas::
 * Visibility Pragmas::
+* Push/Pop Macro Pragmas::
 @end menu
 
 @node ARM Pragmas
@@ -11064,11 +11065,11 @@ way of knowing that that happened.)
 @node Structure-Packing Pragmas
 @subsection Structure-Packing Pragmas
 
-For compatibility with Win32, GCC supports a set of @code{#pragma}
-directives which change the maximum alignment of members of structures
-(other than zero-width bitfields), unions, and classes subsequently
-defined.  The @var{n} value below always is required to be a small power
-of two and specifies the new alignment in bytes.
+For compatibility with Microsoft Windows compilers, GCC supports a
+set of @code{#pragma} directives which change the maximum alignment of
+members of structures (other than zero-width bitfields), unions, and
+classes subsequently defined. The @var{n} value below always is required
+to be a small power of two and specifies the new alignment in bytes.
 
 @enumerate
 @item @code{#pragma pack(@var{n})} simply sets the new alignment.
@@ -11183,6 +11184,41 @@ member or instantiation, you must use an attribute.
 
 @end table
 
+
+@node Push/Pop Macro Pragmas
+@subsection Push/Pop Macro Pragmas
+
+For compatibility with Microsoft Windows compilers, GCC supports
+@samp{#pragma push_macro(@var{"macro_name"})}
+and @samp{#pragma pop_macro(@var{"macro_name"})}.
+
+@table @code
+@item #pragma push_macro(@var{"macro_name"})
+@cindex pragma, push_macro
+This pragma saves the value of the macro named as @var{macro_name} to
+the top of the stack for this macro.
+
+@item #pragma pop_macro(@var{"macro_name"})
+@cindex pragma, pop_macro
+This pragma sets the value of the macro named as @var{macro_name} to
+the value on top of the stack for this macro. If the stack for
+@var{macro_name} is empty, the value of the macro remains unchanged.
+@end table
+
+For example:
+
+@smallexample
+#define X  1
+#pragma push_macro("X")
+#undef X
+#define X -1
+#pragma pop_macro("X")
+int x [X]; 
+@end smallexample
+
+In this example, the definition of X as 1 is saved by @code{#pragma
+push_macro} and restored by @code{#pragma pop_macro}.
+
 @node Unnamed Fields
 @section Unnamed struct/union fields within structs/unions
 @cindex struct