re PR c++/70594 (-fcompare-debug failure)

	PR c++/70594
	* ipa-utils.h (polymorphic_ctor_dtor_p): New prototype.
	* ipa-polymorphic-call.c (polymorphic_ctor_dtor_p): New function.
	(inlined_polymorphic_ctor_dtor_block_p): Use it.
	* tree-ssa-live.c (remove_unused_scope_block_p): When
	in_ctor_dtor_block, avoid discarding not just BLOCKs with
	BLOCK_ABSTRACT_ORIGIN being FUNCTION_DECL, but even when
	block_ultimate_origin is FUNCTION_DECL.
	(remove_unused_locals): If current_function_decl is
	polymorphic_ctor_dtor_p, pass initial true to
	remove_unused_scope_block_p' is_ctor_dtor_block.

From-SVN: r234987

4 files changed, 41 insertions, 13 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 17de27f..8f5f320 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,17 @@
+2016-04-14  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c++/70594
+	* ipa-utils.h (polymorphic_ctor_dtor_p): New prototype.
+	* ipa-polymorphic-call.c (polymorphic_ctor_dtor_p): New function.
+	(inlined_polymorphic_ctor_dtor_block_p): Use it.
+	* tree-ssa-live.c (remove_unused_scope_block_p): When
+	in_ctor_dtor_block, avoid discarding not just BLOCKs with
+	BLOCK_ABSTRACT_ORIGIN being FUNCTION_DECL, but even when
+	block_ultimate_origin is FUNCTION_DECL.
+	(remove_unused_locals): If current_function_decl is
+	polymorphic_ctor_dtor_p, pass initial true to
+	remove_unused_scope_block_p' is_ctor_dtor_block.
+
 2016-04-14  Martin Sebor  <msebor@redhat.com>
 
 	PR c++/69517
diff --git a/gcc/ipa-polymorphic-call.c b/gcc/ipa-polymorphic-call.c
index 0ebbd4a..56f3344 100644
--- a/gcc/ipa-polymorphic-call.c
+++ b/gcc/ipa-polymorphic-call.c
@@ -479,16 +479,12 @@ contains_type_p (tree outer_type, HOST_WIDE_INT offset,
 }
 
 
-/* Return a FUNCTION_DECL if BLOCK represents a constructor or destructor.
+/* Return a FUNCTION_DECL if FN represent a constructor or destructor.
    If CHECK_CLONES is true, also check for clones of ctor/dtors.  */
 
 tree
-inlined_polymorphic_ctor_dtor_block_p (tree block, bool check_clones)
+polymorphic_ctor_dtor_p (tree fn, bool check_clones)
 {
-  tree fn = block_ultimate_origin (block);
-  if (fn == NULL || TREE_CODE (fn) != FUNCTION_DECL)
-    return NULL_TREE;
-
   if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
       || (!DECL_CXX_CONSTRUCTOR_P (fn) && !DECL_CXX_DESTRUCTOR_P (fn)))
     {
@@ -510,6 +506,19 @@ inlined_polymorphic_ctor_dtor_block_p (tree block, bool check_clones)
   return fn;
 }
 
+/* Return a FUNCTION_DECL if BLOCK represents a constructor or destructor.
+   If CHECK_CLONES is true, also check for clones of ctor/dtors.  */
+
+tree
+inlined_polymorphic_ctor_dtor_block_p (tree block, bool check_clones)
+{
+  tree fn = block_ultimate_origin (block);
+  if (fn == NULL || TREE_CODE (fn) != FUNCTION_DECL)
+    return NULL_TREE;
+
+  return polymorphic_ctor_dtor_p (fn, check_clones);
+}
+
 
 /* We know that the instance is stored in variable or parameter
    (not dynamically allocated) and we want to disprove the fact
diff --git a/gcc/ipa-utils.h b/gcc/ipa-utils.h
index 839c6c5..58d2de7 100644
--- a/gcc/ipa-utils.h
+++ b/gcc/ipa-utils.h
@@ -70,6 +70,7 @@ void dump_possible_polymorphic_call_targets (FILE *, tree, HOST_WIDE_INT,
 bool possible_polymorphic_call_target_p (tree, HOST_WIDE_INT,
 				         const ipa_polymorphic_call_context &,
 					 struct cgraph_node *);
+tree polymorphic_ctor_dtor_p (tree, bool);
 tree inlined_polymorphic_ctor_dtor_block_p (tree, bool);
 bool decl_maybe_in_construction_p (tree, tree, gimple *, tree);
 tree vtable_pointer_value_to_binfo (const_tree);
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index c76051a..15fc43f 100644
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -393,14 +393,16 @@ remove_unused_scope_block_p (tree scope, bool in_ctor_dtor_block)
       in_ctor_dtor_block = true;
       unused = false;
     }
-  /* 2) inside such blocks, the outermost block with BLOCK_ABSTRACT_ORIGIN
+  /* 2) inside such blocks, the outermost block with block_ultimate_origin
      being a FUNCTION_DECL.  */
-  else if (in_ctor_dtor_block
-	   && BLOCK_ABSTRACT_ORIGIN (scope)
-	   && TREE_CODE (BLOCK_ABSTRACT_ORIGIN (scope)) == FUNCTION_DECL)
+  else if (in_ctor_dtor_block)
     {
-      in_ctor_dtor_block = false;
-      unused = false;
+      tree fn = block_ultimate_origin (scope);
+      if (fn && TREE_CODE (fn) == FUNCTION_DECL)
+	{
+	  in_ctor_dtor_block = false;
+	  unused = false;
+	}
     }
 
   for (t = &BLOCK_VARS (scope); *t; t = next)
@@ -855,7 +857,9 @@ remove_unused_locals (void)
       cfun->local_decls->truncate (dstidx);
     }
 
-  remove_unused_scope_block_p (DECL_INITIAL (current_function_decl), false);
+  remove_unused_scope_block_p (DECL_INITIAL (current_function_decl),
+			       polymorphic_ctor_dtor_p (current_function_decl,
+							true) != NULL_TREE);
   clear_unused_block_pointer ();
 
   BITMAP_FREE (usedvars);