re PR debug/49032 (-gstabs generates reference to deleted static variable)

	PR debug/49032
	* dbxout.c: Include cgraph.h.
	(dbxout_expand_expr): If a VAR_DECL is TREE_STATIC, not written
	and without value expr, return NULL if no varpool node exists for
	it or if it is not needed.
	* Makefile.in (dbxout.o): Depend on $(CGRAPH_H).

	* gcc.dg/debug/pr49032.c: New test.

From-SVN: r174083

gcc/ChangeLog

 2011-05-23  Jakub Jelinek  <jakub@redhat.com>
 
+	PR debug/49032
+	* dbxout.c: Include cgraph.h.
+	(dbxout_expand_expr): If a VAR_DECL is TREE_STATIC, not written
+	and without value expr, return NULL if no varpool node exists for
+	it or if it is not needed.
+	* Makefile.in (dbxout.o): Depend on $(CGRAPH_H).
+
 	PR c/49120
 	* c-decl.c (start_decl): Convert expr to void_type_node.
 

gcc/Makefile.in

@@ -2957,7 +2957,8 @@ optabs.o : optabs.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(RTL_H) \
 dbxout.o : dbxout.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H) \
    $(RTL_H) $(FLAGS_H) $(REGS_H) debug.h $(TM_P_H) $(TARGET_H) $(FUNCTION_H) \
    langhooks.h insn-config.h reload.h $(GSTAB_H) xcoffout.h output.h dbxout.h \
-   toplev.h $(DIAGNOSTIC_CORE_H) $(GGC_H) $(OBSTACK_H) $(EXPR_H) gt-dbxout.h
+   toplev.h $(DIAGNOSTIC_CORE_H) $(GGC_H) $(OBSTACK_H) $(EXPR_H) $(CGRAPH_H) \
+   gt-dbxout.h
 debug.o : debug.c debug.h $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) $(TREE_H)
 sdbout.o : sdbout.c $(CONFIG_H) $(SYSTEM_H) coretypes.h $(TM_H) debug.h \
    $(TREE_H) $(GGC_H) $(RTL_H) $(REGS_H) $(FLAGS_H) insn-config.h \

gcc/dbxout.c

@@ -91,6 +91,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "langhooks.h"
 #include "obstack.h"
 #include "expr.h"
+#include "cgraph.h"
 
 #ifdef XCOFF_DEBUGGING_INFO
 #include "xcoffout.h"
@@ -2470,6 +2471,20 @@ dbxout_expand_expr (tree expr)
 	 disable debug info for these variables.  */
       if (!targetm.have_tls && DECL_THREAD_LOCAL_P (expr))
 	return NULL;
+      if (TREE_STATIC (expr)
+	  && !TREE_ASM_WRITTEN (expr)
+	  && !DECL_HAS_VALUE_EXPR_P (expr)
+	  && !TREE_PUBLIC (expr)
+	  && DECL_RTL_SET_P (expr)
+	  && MEM_P (DECL_RTL (expr)))
+	{
+	  /* If this is a var that might not be actually output,
+	     return NULL, otherwise stabs might reference an undefined
+	     symbol.  */
+	  struct varpool_node *node = varpool_get_node (expr);
+	  if (!node || !node->needed)
+	    return NULL;
+	}
       /* FALLTHRU */
 
     case PARM_DECL:

gcc/testsuite/ChangeLog

 2011-05-23  Jakub Jelinek  <jakub@redhat.com>
 
+	PR debug/49032
+	* gcc.dg/debug/pr49032.c: New test.
+
 	PR c/49120
 	* gcc.dg/pr49120.c: New test.
 

gcc/testsuite/gcc.dg/debug/pr49032.c

+/* PR debug/49032 */
+/* { dg-do link } */
+
+static int s = 42;
+
+int
+main ()
+{
+  int *l[18] = { &s, &s, &s, &s, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+  return 0;
+}