re PR c++/89285 (ICE after casting the this pointer in the constructor in C++17 mode)

	PR c++/89285
	* builtins.c (fold_builtin_arith_overflow): If first two args are
	INTEGER_CSTs, set intres and ovfres to constants rather than calls
	to ifn.

	* constexpr.c (struct constexpr_fundef): Add parms and result members.
	(retrieve_constexpr_fundef): Adjust for the above change.
	(register_constexpr_fundef): Save constexpr body with copy_fn,
	temporarily set DECL_CONTEXT on DECL_RESULT before that.
	(get_fundef_copy): Change FUN argument to FUNDEF with
	constexpr_fundef * type, grab body and parms/result out of
	constexpr_fundef struct and temporarily change it for copy_fn calls
	too.
	(cxx_eval_builtin_function_call): For __builtin_FUNCTION temporarily
	adjust current_function_decl from ctx->call context.  Test
	!potential_constant_expression instead of !is_constant_expression.
	(cxx_bind_parameters_in_call): Grab parameters from new_call.  Undo
	convert_for_arg_passing changes for TREE_ADDRESSABLE type passing.
	(cxx_eval_call_expression): Adjust get_fundef_copy caller.
	(cxx_eval_conditional_expression): For IF_STMT, allow then or else
	operands to be NULL.
	(label_matches): Handle BREAK_STMT and CONTINUE_STMT.
	(cxx_eval_loop_expr): Add support for FOR_STMT, WHILE_STMT and DO_STMT.
	(cxx_eval_switch_expr): Add support for SWITCH_STMT.
	(cxx_eval_constant_expression): Handle IF_STMT, FOR_STMT, WHILE_STMT,
	DO_STMT, CONTINUE_STMT, SWITCH_STMT, BREAK_STMT and CONTINUE_STMT.
	For SIZEOF_EXPR, recurse on the result of fold_sizeof_expr.  Ignore
	DECL_EXPR with USING_DECL operand.
	* lambda.c (maybe_add_lambda_conv_op): Build thisarg using
	build_int_cst to make it a valid constant expression.

	* g++.dg/ubsan/vptr-4.C: Expect reinterpret_cast errors.
	* g++.dg/cpp1y/constexpr-84192.C (f2): Adjust expected diagnostics.
	* g++.dg/cpp1y/constexpr-70265-2.C (foo): Adjust expected line of
	diagnostics.
	* g++.dg/cpp1y/constexpr-89285.C: New test.
	* g++.dg/cpp0x/constexpr-arith-overflow.C (add, sub, mul): Ifdef out
	for C++11.
	(TEST_ADD, TEST_SUB, TEST_MUL): Define to Assert (true) for C++11.
	* g++.dg/cpp0x/constexpr-arith-overflow2.C: New test.

From-SVN: r269078

1 files changed, 25 insertions, 15 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index 6f266ad..c19ca30 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -9302,8 +9302,7 @@ fold_builtin_arith_overflow (location_t loc, enum built_in_function fcode,
 			     tree arg0, tree arg1, tree arg2)
 {
   enum internal_fn ifn = IFN_LAST;
-  /* The code of the expression corresponding to the type-generic
-     built-in, or ERROR_MARK for the type-specific ones.  */
+  /* The code of the expression corresponding to the built-in.  */
   enum tree_code opcode = ERROR_MARK;
   bool ovf_only = false;
 
@@ -9313,42 +9312,39 @@ fold_builtin_arith_overflow (location_t loc, enum built_in_function fcode,
       ovf_only = true;
       /* FALLTHRU */
     case BUILT_IN_ADD_OVERFLOW:
-      opcode = PLUS_EXPR;
-      /* FALLTHRU */
     case BUILT_IN_SADD_OVERFLOW:
     case BUILT_IN_SADDL_OVERFLOW:
     case BUILT_IN_SADDLL_OVERFLOW:
     case BUILT_IN_UADD_OVERFLOW:
     case BUILT_IN_UADDL_OVERFLOW:
     case BUILT_IN_UADDLL_OVERFLOW:
+      opcode = PLUS_EXPR;
       ifn = IFN_ADD_OVERFLOW;
       break;
     case BUILT_IN_SUB_OVERFLOW_P:
       ovf_only = true;
       /* FALLTHRU */
     case BUILT_IN_SUB_OVERFLOW:
-      opcode = MINUS_EXPR;
-      /* FALLTHRU */
     case BUILT_IN_SSUB_OVERFLOW:
     case BUILT_IN_SSUBL_OVERFLOW:
     case BUILT_IN_SSUBLL_OVERFLOW:
     case BUILT_IN_USUB_OVERFLOW:
     case BUILT_IN_USUBL_OVERFLOW:
     case BUILT_IN_USUBLL_OVERFLOW:
+      opcode = MINUS_EXPR;
       ifn = IFN_SUB_OVERFLOW;
       break;
     case BUILT_IN_MUL_OVERFLOW_P:
       ovf_only = true;
       /* FALLTHRU */
     case BUILT_IN_MUL_OVERFLOW:
-      opcode = MULT_EXPR;
-      /* FALLTHRU */
     case BUILT_IN_SMUL_OVERFLOW:
     case BUILT_IN_SMULL_OVERFLOW:
     case BUILT_IN_SMULLL_OVERFLOW:
     case BUILT_IN_UMUL_OVERFLOW:
     case BUILT_IN_UMULL_OVERFLOW:
     case BUILT_IN_UMULLL_OVERFLOW:
+      opcode = MULT_EXPR;
       ifn = IFN_MUL_OVERFLOW;
       break;
     default:
@@ -9373,13 +9369,27 @@ fold_builtin_arith_overflow (location_t loc, enum built_in_function fcode,
 				 ? boolean_true_node : boolean_false_node,
 				 arg2);
 
-  tree ctype = build_complex_type (type);
-  tree call = build_call_expr_internal_loc (loc, ifn, ctype,
-					    2, arg0, arg1);
-  tree tgt = save_expr (call);
-  tree intres = build1_loc (loc, REALPART_EXPR, type, tgt);
-  tree ovfres = build1_loc (loc, IMAGPART_EXPR, type, tgt);
-  ovfres = fold_convert_loc (loc, boolean_type_node, ovfres);
+  tree intres, ovfres;
+  if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
+    {
+      intres = fold_binary_loc (loc, opcode, type,
+				fold_convert_loc (loc, type, arg0),
+				fold_convert_loc (loc, type, arg1));
+      if (TREE_OVERFLOW (intres))
+	intres = drop_tree_overflow (intres);
+      ovfres = (arith_overflowed_p (opcode, type, arg0, arg1)
+		? boolean_true_node : boolean_false_node);
+    }
+  else
+    {
+      tree ctype = build_complex_type (type);
+      tree call = build_call_expr_internal_loc (loc, ifn, ctype, 2,
+						arg0, arg1);
+      tree tgt = save_expr (call);
+      intres = build1_loc (loc, REALPART_EXPR, type, tgt);
+      ovfres = build1_loc (loc, IMAGPART_EXPR, type, tgt);
+      ovfres = fold_convert_loc (loc, boolean_type_node, ovfres);
+    }
 
   if (ovf_only)
     return omit_one_operand_loc (loc, boolean_type_node, ovfres, arg2);