Re: patch to make -Wpointer-arith work with glibc 2.1.2pre3

[Jim Kingdon <kingdon at redhat dot com>]

Richard Henderson writes:

> This could all be tidied a bit by creating a couple of macros near
> the beginning of c-parse.in to do the encoding and decoding.  Also,
> setting the type of `extension' means $<itype>1 can be written $1.

Here you go (sorry for the delay, I plead hurricanes and other
causes).

Let me know if you still aren't happy :-).

Wed Sep  1 09:12:02 1999  Jim Kingdon  <http://developer.redhat.com>

	* c-parse.in: save and restore warn_pointer_arith on __extension__
	along with pedantic.
	(SAVE_WARN_FLAGS, RESTORE_WARN_FLAGS): Added.
	Set the type of extension to itype rather than $<itype>1 kludge.
	* extend.texi (Alternate Keywords): Adjust documentation.

Index: c-parse.in
===================================================================
RCS file: /cvs/egcs/egcs/gcc/c-parse.in,v
retrieving revision 1.23
diff -u -r1.23 c-parse.in
--- c-parse.in	1999/09/07 05:47:29	1.23
+++ c-parse.in	1999/09/21 19:05:43
@@ -185,6 +185,8 @@
 %type <ttype> parmlist_or_identifiers parmlist_or_identifiers_1
 %type <ttype> identifiers_or_typenames
 
+%type <itype> extension
+
 %type <itype> setspecs
 
 %type <ends_in_label> lineno_stmt_or_label lineno_stmt_or_labels stmt_or_label
@@ -227,6 +229,15 @@
 /* 1 if we explained undeclared var errors.  */
 static int undeclared_variable_notice;
 
+/* For __extension__, save/restore the warning flags which are
+   controlled by __extension__.  */
+#define SAVE_WARN_FLAGS() (pedantic | (warn_pointer_arith << 1))
+#define RESTORE_WARN_FLAGS(val) \
+  do {                                     \
+    pedantic = val & 1;                    \
+    warn_pointer_arith = (val >> 1) & 1;   \
+  } while (0)
+
 ifobjc
 /* Objective-C specific information */
 
@@ -297,7 +308,7 @@
 		  else
 		    error ("argument of `asm' is not a constant string"); }
 	| extension extdef
-		{ pedantic = $<itype>1; }
+		{ RESTORE_WARN_FLAGS ($1); }
 	;
 
 datadef:
@@ -438,7 +449,7 @@
 	/* __extension__ turns off -pedantic for following primary.  */
 	| extension cast_expr	  %prec UNARY
 		{ $$ = $2;
-		  pedantic = $<itype>1; }
+		  RESTORE_WARN_FLAGS ($1); }
 	| unop cast_expr  %prec UNARY
 		{ $$ = build_unary_op ($1, $2, 0);
 		  overflow_warning ($$); }
@@ -1002,7 +1013,7 @@
 	| declmods ';'
 		{ pedwarn ("empty declaration"); }
 	| extension decl
-		{ pedantic = $<itype>1; }
+		{ RESTORE_WARN_FLAGS ($1); }
 	;
 
 /* Declspecs which contain at least one type specifier or typedef name.
@@ -1607,7 +1618,7 @@
 		{ $$ = NULL_TREE; }
 	| extension component_decl
 		{ $$ = $2;
-		  pedantic = $<itype>1; }
+		  RESTORE_WARN_FLAGS ($1); }
 	;
 
 components:
@@ -2441,8 +2452,9 @@
 
 extension:
 	EXTENSION
-		{ $<itype>$ = pedantic;
-		  pedantic = 0; }
+		{ $$ = SAVE_WARN_FLAGS();
+		  pedantic = 0;
+		  warn_pointer_arith = 0; }
 	;
 
 ifobjc
*** egcs-1.1.2/gcc/extend.texi~ Mon Jul  6 18:30:12 1998
--- egcs-1.1.2/gcc/extend.texi  Wed Sep  1 09:14:27 1999
***************
*** 2774,2780 ****
  #endif
  @end example
  
! @samp{-pedantic} causes warnings for many GNU C extensions.  You can
  prevent such warnings within one expression by writing
  @code{__extension__} before the expression.  @code{__extension__} has no
  effect aside from this.
--- 2774,2781 ----
  #endif
  @end example
  
! @samp{-pedantic} and other options cause warnings for many
! GNU C extensions.  You can
  prevent such warnings within one expression by writing
  @code{__extension__} before the expression.  @code{__extension__} has no
  effect aside from this.