re PR debug/27574 (MIssing debug info at -O0 for a local variable in a C++ constructor)

gcc/ChangeLog:
2008-11-12  Dodji Seketeli  <dodji@redhat.com>

	PR debug/27574
	* cgraph.h: New abstract_and_needed member to struct cgraph_node.
	* cgraphunit.c (cgraph_analyze_functions): Flag abstract functions
	- which clones are reachable - as "abstract and needed".
	* cgraph.c (cgraph_release_function_body):  If a node is "abstract and needed",
	do not release its DECL_INITIAL() content because that will be needed to emit
	debug info.

gcc/testsuite/ChangeLog:
2008-11-12  Dodji Seketeli  <dodji@redhat.com>

	PR debug/27574
	* g++.dg/debug/dwarf2/local-var-in-contructor.C: New test.

From-SVN: r141807

gcc/ChangeLog

+2008-11-12  Dodji Seketeli  <dodji@redhat.com>
+
+	PR debug/27574
+	* cgraph.h: New abstract_and_needed member to struct cgraph_node.
+	* cgraphunit.c (cgraph_analyze_functions): Flag abstract functions
+	- which clones are reachable - as "abstract and needed".
+	* cgraph.c (cgraph_release_function_body):  If a node is "abstract and needed",
+	do not release its DECL_INITIAL() content because that will be needed to emit
+	debug info.
+
 2008-11-12  Steve Ellcey  <sje@cup.hp.com>
 
 	PR target/27880

gcc/cgraph.c

@@ -936,7 +936,11 @@ cgraph_release_function_body (struct cgraph_node *node)
       DECL_STRUCT_FUNCTION (node->decl) = NULL;
     }
   DECL_SAVED_TREE (node->decl) = NULL;
-  DECL_INITIAL (node->decl) = error_mark_node;
+  /* If the node is abstract and needed, then do not clear DECL_INITIAL
+     of its associated function function declaration because it's
+     needed to emit debug info later.  */
+  if (!node->abstract_and_needed)
+    DECL_INITIAL (node->decl) = error_mark_node;
 }
 
 /* Remove the node from cgraph.  */

gcc/cgraph.h

@@ -166,6 +166,9 @@ struct cgraph_node GTY((chain_next ("%h.next"), chain_prev ("%h.previous")))
   /* Set when function must be output - it is externally visible
      or its address is taken.  */
   unsigned needed : 1;
+  /* Set when decl is an abstract function pointed to by the
+     ABSTRACT_DECL_ORIGIN of a reachable function.  */
+  unsigned abstract_and_needed : 1;
   /* Set when function is reachable by call from other function
      that is either reachable or needed.  */
   unsigned reachable : 1;

gcc/cgraphunit.c

@@ -896,6 +896,15 @@ cgraph_analyze_functions (void)
 	if (!edge->callee->reachable)
 	  cgraph_mark_reachable_node (edge->callee);
 
+      /* If decl is a clone of an abstract function, mark that abstract
+	 function so that we don't release its body. The DECL_INITIAL() of that
+         abstract function declaration will be later needed to output debug info.  */
+      if (DECL_ABSTRACT_ORIGIN (decl))
+	{
+	  struct cgraph_node *origin_node = cgraph_node (DECL_ABSTRACT_ORIGIN (decl));
+	  origin_node->abstract_and_needed = true;
+	}
+
       /* We finalize local static variables during constructing callgraph
          edges.  Process their attributes too.  */
       process_function_and_variable_attributes (first_processed,

gcc/final.c

@@ -4187,6 +4187,10 @@ rest_of_handle_final (void)
   timevar_push (TV_SYMOUT);
   (*debug_hooks->function_decl) (current_function_decl);
   timevar_pop (TV_SYMOUT);
+
+  /* Release the blocks that are linked to DECL_INITIAL() to free the memory.  */
+  DECL_INITIAL (current_function_decl) = error_mark_node;
+
   if (DECL_STATIC_CONSTRUCTOR (current_function_decl)
       && targetm.have_ctors_dtors)
     targetm.asm_out.constructor (XEXP (DECL_RTL (current_function_decl), 0),

gcc/testsuite/ChangeLog

+2008-11-12  Dodji Seketeli  <dodji@redhat.com>
+
+	PR debug/27574
+	* g++.dg/debug/dwarf2/local-var-in-contructor.C: New test.
+
 2008-11-12  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc.c-torture/execute/20081112-1.c: New test.

gcc/testsuite/g++.dg/debug/dwarf2/local-var-in-contructor.C

+// Contributed by Dodji Seketeli <dodji@redhat.com>
+// Origin PR27574
+// { dg-do compile }
+// { dg-options "-O0 -g" }
+// { dg-final { scan-assembler "problem" } }
+
+void f (int *)
+{
+}
+
+class A
+{
+public:
+ A(int i);
+};
+
+A::A(int i)
+{
+ int *problem = new int(i);
+ f (problem);
+}
+
+int
+main (void)
+{
+  A a (0);
+
+  return 0;
+}
+