re PR middle-end/58094 (IPA devirt testsuite errors)

	PR middle-end/58094
	* cgraph.h (symtab_semantically_equivalent_p): Declare.
	* tree-tailcall.c: Include ipa-utils.h.
	(find_tail_calls): Use it.
	* ipa-pure-const.c (check_call): Likewise.
	* ipa-utils.c (recursive_call_p): New function.
	* ipa-utils.h (recursive_call_p): Dclare.
	* symtab.c (symtab_nonoverwritable_alias): Fix formatting.
	(symtab_semantically_equivalent_p): New function.
	* Makefile.in (tree-tailcall.o): Update dependencies.

From-SVN: r202316

1 files changed, 39 insertions, 2 deletions

diff --git a/gcc/symtab.c b/gcc/symtab.c
index 253ba98..8dc61d0 100644
--- a/gcc/symtab.c
+++ b/gcc/symtab.c
@@ -1106,11 +1106,48 @@ symtab_nonoverwritable_alias (symtab_node node)
     {
       DECL_STATIC_CONSTRUCTOR (new_decl) = 0;
       DECL_STATIC_DESTRUCTOR (new_decl) = 0;
-      new_node = (symtab_node) cgraph_create_function_alias (new_decl, node->symbol.decl);
+      new_node = (symtab_node) cgraph_create_function_alias
+				 (new_decl, node->symbol.decl);
     }
   else
-    new_node = (symtab_node) varpool_create_variable_alias (new_decl, node->symbol.decl);
+    new_node = (symtab_node) varpool_create_variable_alias (new_decl,
+							    node->symbol.decl);
   symtab_resolve_alias (new_node, node);  
+  gcc_assert (decl_binds_to_current_def_p (new_decl));
   return new_node;
 }
+
+/* Return true if A and B represents semantically equivalent symbols.  */
+
+bool
+symtab_semantically_equivalent_p (symtab_node a,
+				  symtab_node b)
+{
+  enum availability avail;
+  symtab_node ba, bb;
+
+  /* Equivalent functions are equivalent.  */
+  if (a->symbol.decl == b->symbol.decl)
+    return true;
+
+  /* If symbol is not overwritable by different implementation,
+     walk to the base object it defines.  */
+  ba = symtab_alias_ultimate_target (a, &avail);
+  if (avail >= AVAIL_AVAILABLE)
+    {
+      if (ba == b)
+	return true;
+    }
+  else
+    ba = a;
+  bb = symtab_alias_ultimate_target (b, &avail);
+  if (avail >= AVAIL_AVAILABLE)
+    {
+      if (a == bb)
+	return true;
+    }
+  else
+    bb = b;
+  return bb == ba;
+}
 #include "gt-symtab.h"