[C++ PATCH]: Fix bug 2936 (a regression)

[Nathan Sidwell <nathan at codesourcery dot com>]

Hi,
I've installed this obvious fix for bug 2936 which was a tree inlining
regression from 2.95.

Two bugs,
1) The VAR_DECL for a function scope anonymous union never had its
DECL_CONTEXT set.
2) When copying that decl for inlining we need to copy and duplicate the
DECL_ANON_UNION_ELEMS.

booted and tested on i686-pc-linux-gnu, installed on mainline & branch.

nathan
-- 
Dr Nathan Sidwell   ::   http://www.codesourcery.com   ::   CodeSourcery LLC
         'But that's a lie.' - 'Yes it is. What's your point?'
nathan@codesourcery.com : http://www.cs.bris.ac.uk/~nathan/ : nathan@acm.org
2001-05-30  Nathan Sidwell  <nathan@codesourcery.com>

	PR g++/2936
	* decl.c (finish_anon_union): Copy context.
	* optimize.c (remap_decl): Remap anonymous aggregate members too.

2001-05-30  Nathan Sidwell  <nathan@codesourcery.com>

	* g++.old-deja/g++.other/optimize3.C: New file.

Index: cp/optimize.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/optimize.c,v
retrieving revision 1.51.2.18
diff -c -3 -p -r1.51.2.18 optimize.c
*** optimize.c	2001/05/23 02:08:54	1.51.2.18
--- optimize.c	2001/05/30 08:38:57
*************** static void update_cloned_parm PARAMS ((
*** 106,113 ****
     decisions about when a function is too big to inline.  */
  #define INSNS_PER_STMT (10)
  
! /* Remap DECL during the copying of the BLOCK tree for the function.
!    DATA is really an `inline_data *'.  */
  
  static tree
  remap_decl (decl, id)
--- 106,112 ----
     decisions about when a function is too big to inline.  */
  #define INSNS_PER_STMT (10)
  
! /* Remap DECL during the copying of the BLOCK tree for the function.  */
  
  static tree
  remap_decl (decl, id)
*************** remap_decl (decl, id)
*** 149,154 ****
--- 148,173 ----
  		     copy_body_r, id, NULL);
  	}
  
+       if (!DECL_NAME (t) && TREE_TYPE (t)
+ 	  && ANON_AGGR_TYPE_P (TREE_TYPE ((t))))
+ 	{
+ 	  /* For a VAR_DECL of anonymous type, we must also copy the
+ 	     member VAR_DECLS here and rechain the
+ 	     DECL_ANON_UNION_ELEMS. */
+ 	  tree members = NULL;
+ 	  tree src;
+ 	  
+ 	  for (src = DECL_ANON_UNION_ELEMS (t); src;
+ 	       src = TREE_CHAIN (src))
+ 	    {
+ 	      tree member = remap_decl (TREE_VALUE (src), id);
+ 
+ 	      my_friendly_assert (!TREE_PURPOSE (src), 20010529);
+ 	      members = tree_cons (NULL, member, members);
+ 	    }
+ 	  DECL_ANON_UNION_ELEMS (t) = nreverse (members);
+ 	}
+       
        /* Remember it, so that if we encounter this local entity
  	 again we can reuse this copy.  */
        n = splay_tree_insert (id->decl_map,
Index: testsuite/g++.old-deja/g++.other/optimize3.C
===================================================================
RCS file: optimize3.C
diff -N optimize3.C
*** /dev/null	Tue May  5 13:32:27 1998
--- optimize3.C	Wed May 30 01:39:00 2001
***************
*** 0 ****
--- 1,38 ----
+ // Special g++ Options: -O2
+ // 
+ // Copyright (C) 2001 Free Software Foundation, Inc.
+ // Contributed by Nathan Sidwell 29 May 2001 <nathan@codesourcery.com>
+ 
+ // Bug 2936. We ICE'd on tree inlining a function with an anonymous
+ // union decl.
+ 
+ inline const unsigned char *Foo (const char *string)
+ {
+   union
+   {
+     const char *p1;
+     const unsigned char *p2;
+   };
+   p1 = 0;
+   p2 = 0;
+ 
+ 
+   p1 = string;
+   return p2;
+   
+ }
+ 
+ const unsigned char *Baz (const char *string)
+ {
+   return Foo (string);
+ }
+ 
+ int main ()
+ {
+   const char *string = "s";
+   const unsigned char *result;
+ 
+   result = Baz (string);
+   return (static_cast <const void *> (result)
+ 	  != static_cast <const void *> (string));
+ }