[PATCH] Fix locus on C structs with forward declaration

[Jakub Jelinek]

Hi!

Unlike C++, in C DW_TAG_structure_type contains ATM the locus of the first
forward declaration (if any), rather than the real definition.  The latter
is usually more useful for debugger purposes.

Fixed thusly.  Bootstrapped/regtested on i686-linux and bootstrapped on
x86_64-linux, ok for trunk?

2009-09-17  Jakub Jelinek  <jakub@redhat.com>

	* c-decl.c (finish_struct): Adjust DECL_SOURCE_LOCATION of
	TYPE_STUB_DECL.

	* gcc.dg/debug/dwarf2/struct-loc1.c: New test.

--- gcc/c-decl.c.jj	2009-09-16 09:06:29.000000000 +0200
+++ gcc/c-decl.c	2009-09-17 11:53:09.000000000 +0200
@@ -6859,6 +6859,11 @@ finish_struct (location_t loc, tree t, t
     }
   C_TYPE_INCOMPLETE_VARS (TYPE_MAIN_VARIANT (t)) = 0;
 
+  /* Update type location to the one of the definition, instead of e.g.
+     a forward declaration.  */
+  if (TYPE_STUB_DECL (t))
+    DECL_SOURCE_LOCATION (TYPE_STUB_DECL (t)) = loc;
+
   /* Finish debugging output for this type.  */
   rest_of_type_compilation (t, toplevel);
 
--- gcc/testsuite/gcc.dg/debug/dwarf2/struct-loc1.c.jj	2009-09-17 12:13:14.000000000 +0200
+++ gcc/testsuite/gcc.dg/debug/dwarf2/struct-loc1.c	2009-09-17 12:17:42.000000000 +0200
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-g -O0 -dA -fno-merge-debug-strings" } */
+
+struct foo;
+struct foo *obj;
+struct foo
+{
+  int x;
+};
+
+int
+main ()
+{
+  return 0;
+}
+
+/* { dg-final { scan-assembler "DW_TAG_structure_type\[^\\r\\n\]*\[\\r\\n\]+\[^\\r\\n\]*\"foo\[^\\r\\n\]*DW_AT_name(\[^\\r\\n\]*\[\\r\\n\]+\[^\\r\\n\]*DW_AT_)*\[^\\r\\n\]*\[\\r\\n\]+\[^\\r\\n\]*\[^0-9a-fA-FxX](0x)?6\[^0-9a-fA-FxX]\[^\\r\\n\]*DW_AT_decl_line" } } */

	Jakub