re PR c++/42338 ([c++0x] ICE on decltype usage with templates)

	PR c++/42338
	* mangle.c (write_expression): Handle tree codes that have extra
	arguments in the middle-end.
	* cp-demangle.c (d_print_comp): Fix array index printing.

From-SVN: r156103

gcc/cp/ChangeLog

+2010-01-20  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42338
+	* mangle.c (write_expression): Handle tree codes that have extra
+	arguments in the middle-end.
+
 2010-01-20  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/42038

gcc/cp/mangle.c

@@ -2481,7 +2481,7 @@ write_expression (tree expr)
     }
   else
     {
-      int i;
+      int i, len;
       const char *name;
 
       /* When we bind a variable or function to a non-type template
@@ -2582,7 +2582,27 @@ write_expression (tree expr)
 	  break;
 
 	default:
-	  for (i = 0; i < TREE_OPERAND_LENGTH (expr); ++i)
+	  /* In the middle-end, some expressions have more operands than
+	     they do in templates (and mangling).  */
+	  switch (code)
+	    {
+	    case PREINCREMENT_EXPR:
+	    case PREDECREMENT_EXPR:
+	    case POSTINCREMENT_EXPR:
+	    case POSTDECREMENT_EXPR:
+	      len = 1;
+	      break;
+
+	    case ARRAY_REF:
+	      len = 2;
+	      break;
+
+	    default:
+	      len = TREE_OPERAND_LENGTH (expr);
+	      break;
+	    }
+
+	  for (i = 0; i < len; ++i)
 	    {
 	      tree operand = TREE_OPERAND (expr, i);
 	      /* As a GNU extension, the middle operand of a

gcc/testsuite/g++.dg/abi/mangle39.C

+// PR c++/42338
+// { dg-options "-std=c++0x" }
+// { dg-final { scan-assembler "_Z1fIPiEDTcmppfp_Li0EET_" } }
+// { dg-final { scan-assembler "_Z1gIiEvRK1AIT_EDTixfp_Li0EE" } }
+
+template<typename T>
+auto f(T t) -> decltype(++t, 0)
+{
+  ++t;
+  return 0;
+}
+
+template <class T>
+struct A
+{
+  T operator[](int) const { return 0; }
+};
+
+template< typename T >
+void g(const A<T> &a, decltype(a[0]) t) { }
+
+int main()
+{
+  f((int*)0);
+
+  A<int> a;
+  g(a,1);
+}

libiberty/ChangeLog

+2010-01-20  Jason Merrill  <jason@redhat.com>
+
+	PR c++/42338
+	* cp-demangle.c (d_print_comp): Fix array index printing.
+
 2010-01-11  Tristan Gingold  <gingold@adacore.com>
 
 	* cplus-dem.c (ada_demangle): Remove prototype.

libiberty/cp-demangle.c

@@ -4037,9 +4037,18 @@ d_print_comp (struct d_print_info *dpi,
 	d_append_char (dpi, '(');
 
       d_print_subexpr (dpi, d_left (d_right (dc)));
-      if (strcmp (d_left (dc)->u.s_operator.op->code, "cl") != 0)
-	d_print_expr_op (dpi, d_left (dc));
-      d_print_subexpr (dpi, d_right (d_right (dc)));
+      if (strcmp (d_left (dc)->u.s_operator.op->code, "ix") == 0)
+	{
+	  d_append_char (dpi, '[');
+	  d_print_comp (dpi, d_right (d_right (dc)));
+	  d_append_char (dpi, ']');
+	}
+      else
+	{
+	  if (strcmp (d_left (dc)->u.s_operator.op->code, "cl") != 0)
+	    d_print_expr_op (dpi, d_left (dc));
+	  d_print_subexpr (dpi, d_right (d_right (dc)));
+	}
 
       if (d_left (dc)->type == DEMANGLE_COMPONENT_OPERATOR
 	  && d_left (dc)->u.s_operator.op->len == 1