cp-demangle.c (struct d_component_stack): New structure.

libiberty/
2014-05-08  Gary Benson  <gbenson@redhat.com>

	* cp-demangle.c (struct d_component_stack): New structure.
	(struct d_print_info): New field component_stack.
	(d_print_init): Initialize the above.
	(d_print_comp_inner): Renamed from d_print_comp.
	Do not restore template stack if it would cause a loop.
	(d_print_comp): New function.
	* testsuite/demangle-expected: New test cases.

From-SVN: r210205

libiberty/ChangeLog

+2014-05-08  Gary Benson  <gbenson@redhat.com>
+
+	* cp-demangle.c (struct d_component_stack): New structure.
+	(struct d_print_info): New field component_stack.
+	(d_print_init): Initialize the above.
+	(d_print_comp_inner): Renamed from d_print_comp.
+	Do not restore template stack if it would cause a loop.
+	(d_print_comp): New function.
+	* testsuite/demangle-expected: New test cases.
+
 2014-04-17  Jakub Jelinek  <jakub@redhat.com>
 
 	PR sanitizer/56781

libiberty/cp-demangle.c

@@ -275,6 +275,16 @@ struct d_growable_string
   int allocation_failure;
 };
 
+/* Stack of components, innermost first, used to avoid loops.  */
+
+struct d_component_stack
+{
+  /* This component.  */
+  const struct demangle_component *dc;
+  /* This component's parent.  */
+  const struct d_component_stack *parent;
+};
+
 /* A demangle component and some scope captured when it was first
    traversed.  */
 
@@ -327,6 +337,8 @@ struct d_print_info
   int pack_index;
   /* Number of d_print_flush calls so far.  */
   unsigned long int flush_count;
+  /* Stack of components, innermost first, used to avoid loops.  */
+  const struct d_component_stack *component_stack;
   /* Array of saved scopes for evaluating substitutions.  */
   struct d_saved_scope *saved_scopes;
   /* Index of the next unused saved scope in the above array.  */
@@ -3934,6 +3946,8 @@ d_print_init (struct d_print_info *dpi, demangle_callbackref callback,
 
   dpi->demangle_failure = 0;
 
+  dpi->component_stack = NULL;
+
   dpi->saved_scopes = NULL;
   dpi->next_saved_scope = 0;
   dpi->num_saved_scopes = 0;
@@ -4269,8 +4283,8 @@ d_get_saved_scope (struct d_print_info *dpi,
 /* Subroutine to handle components.  */
 
 static void
-d_print_comp (struct d_print_info *dpi, int options,
-              const struct demangle_component *dc)
+d_print_comp_inner (struct d_print_info *dpi, int options,
+		  const struct demangle_component *dc)
 {
   /* Magic variable to let reference smashing skip over the next modifier
      without needing to modify *dc.  */
@@ -4673,11 +4687,30 @@ d_print_comp (struct d_print_info *dpi, int options,
 	      }
 	    else
 	      {
+		const struct d_component_stack *dcse;
+		int found_self_or_parent = 0;
+
 		/* This traversal is reentering SUB as a substition.
-		   Restore the original templates temporarily.  */
-		saved_templates = dpi->templates;
-		dpi->templates = scope->templates;
-		need_template_restore = 1;
+		   If we are not beneath SUB or DC in the tree then we
+		   need to restore SUB's template stack temporarily.  */
+		for (dcse = dpi->component_stack; dcse != NULL;
+		     dcse = dcse->parent)
+		  {
+		    if (dcse->dc == sub
+			|| (dcse->dc == dc
+			    && dcse != dpi->component_stack))
+		      {
+			found_self_or_parent = 1;
+			break;
+		      }
+		  }
+
+		if (!found_self_or_parent)
+		  {
+		    saved_templates = dpi->templates;
+		    dpi->templates = scope->templates;
+		    need_template_restore = 1;
+		  }
 	      }
 
 	    a = d_lookup_template_argument (dpi, sub);
@@ -5316,6 +5349,21 @@ d_print_comp (struct d_print_info *dpi, int options,
     }
 }
 
+static void
+d_print_comp (struct d_print_info *dpi, int options,
+	      const struct demangle_component *dc)
+{
+  struct d_component_stack self;
+
+  self.dc = dc;
+  self.parent = dpi->component_stack;
+  dpi->component_stack = &self;
+
+  d_print_comp_inner (dpi, options, dc);
+
+  dpi->component_stack = self.parent;
+}
+
 /* Print a Java dentifier.  For Java we try to handle encoded extended
    Unicode characters.  The C++ ABI doesn't mention Unicode encoding,
    so we don't it for C++.  Characters are encoded as