diff mbox

[C] Fix debug info locus of enum with previous forward declaration (PR c/79969)

Message ID 20170309092443.GF22703@tucnak
State New
Headers show

Commit Message

Jakub Jelinek March 9, 2017, 9:24 a.m. UTC 
Hi!

Similarly to https://gcc.gnu.org/ml/gcc-patches/2009-09/msg01161.html
the C FE gets wrong the location of DW_TAG_enumeral_type if there is a
forward declaration.  If we e.g. have a variable that is first declared
extern and then defined, we emit DW_TAG_variable with the location of the
first declaration and then another DW_TAG_variable with DW_AT_specification
pointing to the previous one for the definition, with locus of the
definition.  That is not what we do for enums, there is just one DIE, so we
should use the more descriptive from the locations, which is the definition.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2017-03-09  Jakub Jelinek  <jakub@redhat.com>

	PR c/79969
	* c-decl.c (start_enum): Adjust DECL_SOURCE_LOCATION of
	TYPE_STUB_DECL.

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


	Jakub
diff mbox

Patch

--- gcc/c/c-decl.c.jj	2017-03-05 22:39:45.000000000 +0100
+++ gcc/c/c-decl.c	2017-03-09 08:19:33.100042166 +0100
@@ -8201,6 +8201,10 @@  start_enum (location_t loc, struct c_enu
       enumtype = make_node (ENUMERAL_TYPE);
       pushtag (loc, name, enumtype);
     }
+  /* Update type location to the one of the definition, instead of e.g.
+     a forward declaration.  */
+  else if (TYPE_STUB_DECL (enumtype))
+    DECL_SOURCE_LOCATION (TYPE_STUB_DECL (enumtype)) = loc;
 
   if (C_TYPE_BEING_DEFINED (enumtype))
     error_at (loc, "nested redefinition of %<enum %E%>", name);
--- gcc/testsuite/gcc.dg/debug/dwarf2/enum-loc1.c.jj	2017-03-09 08:09:30.742037844 +0100
+++ gcc/testsuite/gcc.dg/debug/dwarf2/enum-loc1.c	2017-03-09 08:16:45.202268438 +0100
@@ -0,0 +1,19 @@ 
+/* PR c/79969 */
+/* { dg-do compile } */
+/* { dg-options "-gdwarf -dA -fno-merge-debug-strings" } */
+
+enum ENUMTAG;
+
+enum ENUMTAG
+{
+  B = 1,
+  C = 2
+};
+
+void
+bar (void)
+{
+  enum ENUMTAG a = C;
+}
+
+/* { dg-final { scan-assembler "DW_TAG_enumeration_type\[^\\r\\n\]*\[\\r\\n\]+\[^\\r\\n\]*\"ENUMTAG\[^\\r\\n\]*DW_AT_name(\[^\\r\\n\]*\[\\r\\n\]+\[^\\r\\n\]*DW_AT_)*\[^\\r\\n\]*\[\\r\\n\]+\[^\\r\\n\]*\[^0-9a-fA-FxX](0x)?7\[^0-9a-fA-FxX]\[^\\r\\n\]*DW_AT_decl_line" } } */