Patch PING^2: fix --enable-mapped-location build failures

[Per Bothner <per at bothner dot com>]

These patches fix various problems with boostrapping with
--enable-mapped-location.  The orginal patch was posted 02/11.
Mark approved the C++ part, so I've checked that in.
No response on the other parts.

I have added two changes since then:
(1) The c_parser_for_statement is a fix for a local variable that may
be used uninitialized.  I'm guessing the back-end doesn't catch that
when the location_t local is a structure as opposed to an int?
(2) I've ran into a problem dwarf2out.c crashing when passed a not-found
class.  In mainline dwarf2out.c bypasses the class if DECL_IS_BUILTIN -
and a not-found class gets a zero line number.  I think this is a jc1
bug, and I'm looking into it, but for now it's probably easiest to use
the old DECL_IS_BUILTIN definition.

As as inducement:  As soon as I've checked this in, I'll post the
patches for correct column numbers of local variables, for C and C++.
--
	--Per Bothner
per@bothner.com   http://per.bothner.com/

2005-03-01  Per Bothner  <per@bothner.com>

	Various fixes to allow us to again build if --enable-mapped-location:
	* c-decl.c (finish_function): Use SET_EXPR_LOCATION instead of
	unavailable annotate_with_file_line, if USE_MAPPED_LOCATION.
	* tree-cfg.c (remove_bb): If USE_MAPPED_LOCATION, change type of
	local variable loc. Change logic appropriately.
	* tree-vect-transform.c (vect_finish_stmt_generation): Use
	EXPR_LOCATION rather than EXPR_LOCUS if USE_MAPPED_LOCATION.	
	* c-parser.c (c_parser_for_statement): Initialize loc variable.
	* tree.h (DECL_IS_BUILTIN): Temporarily revert definition of
	DECL_IS_BUILTIN in the USE_MAPPED_LOCATION because of jc1 issues.

Index: c-decl.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-decl.c,v
retrieving revision 1.631
diff -u -p -r1.631 c-decl.c
--- c-decl.c	25 Feb 2005 23:20:35 -0000	1.631
+++ c-decl.c	2 Mar 2005 00:16:58 -0000
@@ -6335,7 +6335,11 @@ finish_function (void)
 	      /* Hack.  We don't want the middle-end to warn that this
 		 return is unreachable, so put the statement on the
 		 special line 0.  */
+#ifdef USE_MAPPED_LOCATION
+	      SET_EXPR_LOCATION (stmt, UNKNOWN_LOCATION);
+#else
 	      annotate_with_file_line (stmt, input_filename, 0);
+#endif
 	    }
 	}
     }
Index: c-parser.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/c-parser.c,v
retrieving revision 2.2
diff -u -p -r2.2 c-parser.c
--- c-parser.c	28 Feb 2005 19:22:26 -0000	2.2
+++ c-parser.c	2 Mar 2005 00:16:59 -0000
@@ -3760,7 +3760,7 @@ static void
 c_parser_for_statement (c_parser *parser)
 {
   tree block, cond, incr, save_break, save_cont, body;
-  location_t loc;
+  location_t loc = UNKNOWN_LOCATION;
   gcc_assert (c_parser_next_token_is_keyword (parser, RID_FOR));
   c_parser_consume_token (parser);
   block = c_begin_compound_stmt (flag_isoc99);
Index: tree-cfg.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-cfg.c,v
retrieving revision 2.152
diff -u -p -r2.152 tree-cfg.c
--- tree-cfg.c	28 Feb 2005 18:18:25 -0000	2.152
+++ tree-cfg.c	2 Mar 2005 00:17:08 -0000
@@ -2013,7 +2013,11 @@ static void
 remove_bb (basic_block bb)
 {
   block_stmt_iterator i;
+#ifdef USE_MAPPED_LOCATION
+  source_location loc = UNKNOWN_LOCATION;
+#else
   source_locus loc = 0;
+#endif
 
   if (dump_file)
     {
@@ -2052,15 +2056,15 @@ remove_bb (basic_block bb)
 	 program that are indeed unreachable.  */
       if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc)
 	{
-	  source_locus t;
-
 #ifdef USE_MAPPED_LOCATION
-	  t = EXPR_LOCATION (stmt);
+	  if (EXPR_HAS_LOCATION (stmt))
+	    loc = EXPR_LOCATION (stmt);
 #else
+	  source_locus t;
 	  t = EXPR_LOCUS (stmt);
-#endif
 	  if (t && LOCATION_LINE (*t) > 0)
 	    loc = t;
+#endif
 	}
     }
 
@@ -2068,10 +2072,11 @@ remove_bb (basic_block bb)
      block is unreachable.  We walk statements backwards in the
      loop above, so the last statement we process is the first statement
      in the block.  */
-  if (warn_notreached && loc)
 #ifdef USE_MAPPED_LOCATION
+  if (warn_notreached && loc != UNKNOWN_LOCATION)
     warning ("%Hwill never be executed", &loc);
 #else
+  if (warn_notreached && loc)
     warning ("%Hwill never be executed", loc);
 #endif
 
Index: tree-vect-transform.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree-vect-transform.c,v
retrieving revision 2.2
diff -u -p -r2.2 tree-vect-transform.c
--- tree-vect-transform.c	1 Mar 2005 13:44:46 -0000	2.2
+++ tree-vect-transform.c	2 Mar 2005 00:17:10 -0000
@@ -661,7 +661,7 @@ vect_finish_stmt_generation (tree stmt, 
 #endif
 
 #ifdef USE_MAPPED_LOCATION
-  SET_EXPR_LOCATION (vec_stmt, EXPR_LOCUS (stmt));
+  SET_EXPR_LOCATION (vec_stmt, EXPR_LOCATION (stmt));
 #else
   SET_EXPR_LOCUS (vec_stmt, EXPR_LOCUS (stmt));
 #endif
Index: tree.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/tree.h,v
retrieving revision 1.694
diff -u -p -r1.694 tree.h
--- tree.h	28 Feb 2005 18:18:26 -0000	1.694
+++ tree.h	2 Mar 2005 00:17:12 -0000
@@ -1957,7 +1957,11 @@ struct tree_binfo GTY (())
 #define DECL_SOURCE_LOCATION(NODE) (DECL_CHECK (NODE)->decl.locus)
 #define DECL_SOURCE_FILE(NODE) LOCATION_FILE (DECL_SOURCE_LOCATION (NODE))
 #define DECL_SOURCE_LINE(NODE) LOCATION_LINE (DECL_SOURCE_LOCATION (NODE))
-#ifdef USE_MAPPED_LOCATION
+#if 0
+/* Should be: #ifdef USE_MAPPED_LOCATION
+   However, there appears to be a jc1 bug that this would expose.
+   (It prevents bookstrapping because dwarf2out tries to emit a
+   non-found class.) FIXME. */
 #define DECL_IS_BUILTIN(DECL) \
   (DECL_SOURCE_LOCATION (DECL) <= BUILTINS_LOCATION)
 #else