semantics.c (check_constexpr_ctor_body_1): New.

/cp
2014-10-09  Paolo Carlini  <paolo.carlini@oracle.com>

	* semantics.c (check_constexpr_ctor_body_1): New.
	(check_constexpr_ctor_body): Use it; add bool parameter.
	(build_data_member_initialization): Handle BIND_EXPR and
	USING_STMT in the main conditional.
	(build_constexpr_constructor_member_initializers): Do not
	handle BIND_EXPR here.
	(constexpr_fn_retval): Handle BIND_EXPR in the switch.
	(massage_constexpr_body): Don't do it here.
	* parser.c (cp_parser_ctor_initializer_opt_and_function_body):
	Adjust check_constexpr_ctor_body call.
	(cp_parser_compound_statement): Do not pedwarn for compound-statement
	in constexpr function in C++14 mode.
	* cp-tree.h (check_constexpr_ctor_body): Update declaration.

/testsuite
2014-10-09  Paolo Carlini  <paolo.carlini@oracle.com>

	* g++.dg/cpp0x/constexpr-using3.C: New.
	* g++.dg/cpp1y/constexpr-local-compound1.C: Likewise.
	* g++.dg/cpp1y/constexpr-type-def-compound1.C: Likewise.
	* g++.dg/cpp1y/constexpr-local1.C: Extend.
	* g++.dg/cpp0x/constexpr-compound.C: Specify expected error.

From-SVN: r216049

gcc/cp/ChangeLog

+2014-10-09  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* semantics.c (check_constexpr_ctor_body_1): New.
+	(check_constexpr_ctor_body): Use it; add bool parameter.
+	(build_data_member_initialization): Handle BIND_EXPR and
+	USING_STMT in the main conditional.
+	(build_constexpr_constructor_member_initializers): Do not
+	handle BIND_EXPR here.
+	(constexpr_fn_retval): Handle BIND_EXPR in the switch.
+	(massage_constexpr_body): Don't do it here.
+	* parser.c (cp_parser_ctor_initializer_opt_and_function_body):
+	Adjust check_constexpr_ctor_body call.
+	(cp_parser_compound_statement): Do not pedwarn for compound-statement
+	in constexpr function in C++14 mode.
+	* cp-tree.h (check_constexpr_ctor_body): Update declaration.
+
 2014-10-09  Jason Merrill  <jason@redhat.com>
 
 	PR c++/63309

gcc/cp/cp-tree.h

@@ -5823,7 +5823,7 @@ extern void finish_handler			(tree);
 extern void finish_cleanup			(tree, tree);
 extern bool literal_type_p (tree);
 extern tree register_constexpr_fundef (tree, tree);
-extern bool check_constexpr_ctor_body (tree, tree);
+extern bool check_constexpr_ctor_body (tree, tree, bool);
 extern tree ensure_literal_type_for_constexpr_object (tree);
 extern bool potential_constant_expression (tree);
 extern bool potential_rvalue_constant_expression (tree);

gcc/cp/parser.c

@@ -9891,7 +9891,7 @@ cp_parser_compound_statement (cp_parser *parser, tree in_statement_expr,
   if (!cp_parser_require (parser, CPP_OPEN_BRACE, RT_OPEN_BRACE))
     return error_mark_node;
   if (DECL_DECLARED_CONSTEXPR_P (current_function_decl)
-      && !function_body)
+      && !function_body && cxx_dialect < cxx14)
     pedwarn (input_location, OPT_Wpedantic,
 	     "compound-statement in constexpr function");
   /* Begin the compound-statement.  */
@@ -19015,7 +19015,7 @@ cp_parser_ctor_initializer_opt_and_function_body (cp_parser *parser,
   /* Parse the function-body.  */
   cp_parser_function_body (parser, in_function_try_block);
   if (check_body_p)
-    check_constexpr_ctor_body (last, list);
+    check_constexpr_ctor_body (last, list, /*complain=*/true);
   /* Finish the function body.  */
   finish_function_body (body);
 

gcc/cp/semantics.c

@@ -7781,8 +7781,12 @@ build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec)
 	 wrong type, but cxx_eval_constant_expression doesn't care.  */
       init = break_out_target_exprs (t);
     }
-  else if (TREE_CODE (t) == DECL_EXPR)
-    /* Declaring a temporary, don't add it to the CONSTRUCTOR.  */
+  else if (TREE_CODE (t) == BIND_EXPR)
+    return build_data_member_initialization (BIND_EXPR_BODY (t), vec);
+  else if (TREE_CODE (t) == DECL_EXPR
+	   || TREE_CODE (t) == USING_STMT)
+    /* Declaring a temporary, don't add it to the CONSTRUCTOR.
+       Likewise for using directives.  */
     return true;
   else
     gcc_unreachable ();
@@ -7835,7 +7839,7 @@ build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec)
   return true;
 }
 
-/* Subroutine of check_constexpr_ctor_body and massage_constexpr_body.
+/* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval.
    In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a 
    BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations.  */
 
@@ -7854,11 +7858,45 @@ check_constexpr_bind_expr_vars (tree t)
   return true;
 }
 
+/* Subroutine of check_constexpr_ctor_body.  */
+
+static bool
+check_constexpr_ctor_body_1 (tree last, tree list)
+{
+  switch (TREE_CODE (list))
+    {
+    case DECL_EXPR:
+      if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL)
+	return true;
+      if (cxx_dialect >= cxx14)
+	return true;
+      return false;
+
+    case CLEANUP_POINT_EXPR:
+      return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0),
+					/*complain=*/false);
+
+    case BIND_EXPR:
+       if (!check_constexpr_bind_expr_vars (list)
+	   || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list),
+					  /*complain=*/false))
+	 return false;
+       return true;
+
+    case USING_STMT:
+    case STATIC_ASSERT:
+      return true;
+
+    default:
+      return false;
+    }
+}
+
 /* Make sure that there are no statements after LAST in the constructor
    body represented by LIST.  */
 
 bool
-check_constexpr_ctor_body (tree last, tree list)
+check_constexpr_ctor_body (tree last, tree list, bool complain)
 {
   bool ok = true;
   if (TREE_CODE (list) == STATEMENT_LIST)
@@ -7869,19 +7907,7 @@ check_constexpr_ctor_body (tree last, tree list)
 	  tree t = tsi_stmt (i);
 	  if (t == last)
 	    break;
-	  if (TREE_CODE (t) == BIND_EXPR)
-	    {
-	      if (!check_constexpr_bind_expr_vars (t))
-		{
-		  ok = false;
-		  break;
-		}
-	      if (!check_constexpr_ctor_body (last, BIND_EXPR_BODY (t)))
-		return false;
-	      else
-		continue;
-	    }
-	  if (TREE_CODE (t) != STATIC_ASSERT)
+	  if (!check_constexpr_ctor_body_1 (last, t))
 	    {
 	      ok = false;
 	      break;
@@ -7889,11 +7915,12 @@ check_constexpr_ctor_body (tree last, tree list)
 	}
     }
   else if (list != last
-	   && TREE_CODE (list) != STATIC_ASSERT)
+	   && !check_constexpr_ctor_body_1 (last, list))
     ok = false;
   if (!ok)
     {
-      error ("constexpr constructor does not have empty body");
+      if (complain)
+	error ("constexpr constructor does not have empty body");
       DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false;
     }
   return ok;
@@ -7983,8 +8010,6 @@ build_constexpr_constructor_member_initializers (tree type, tree body)
 	     "a function-try-block");
       return error_mark_node;
     }
-  else if (TREE_CODE (body) == BIND_EXPR)
-    ok = build_data_member_initialization (BIND_EXPR_BODY (body), &vec);
   else if (EXPR_P (body))
     ok = build_data_member_initialization (body, &vec);
   else
@@ -8052,6 +8077,11 @@ constexpr_fn_retval (tree body)
     case CLEANUP_POINT_EXPR:
       return constexpr_fn_retval (TREE_OPERAND (body, 0));
 
+    case BIND_EXPR:
+      if (!check_constexpr_bind_expr_vars (body))
+	return error_mark_node;
+      return constexpr_fn_retval (BIND_EXPR_BODY (body));
+
     case USING_STMT:
       return NULL_TREE;
 
@@ -8076,9 +8106,6 @@ massage_constexpr_body (tree fun, tree body)
         body = EH_SPEC_STMTS (body);
       if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
 	body = TREE_OPERAND (body, 0);
-      if (TREE_CODE (body) == BIND_EXPR
-	  && check_constexpr_bind_expr_vars (body))
-	body = BIND_EXPR_BODY (body);
       body = constexpr_fn_retval (body);
     }
   return body;

gcc/testsuite/ChangeLog

+2014-10-09  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* g++.dg/cpp0x/constexpr-using3.C: New.
+	* g++.dg/cpp1y/constexpr-local-compound1.C: Likewise.
+	* g++.dg/cpp1y/constexpr-type-def-compound1.C: Likewise.
+	* g++.dg/cpp1y/constexpr-local1.C: Extend.
+	* g++.dg/cpp0x/constexpr-compound.C: Specify expected error.
+
 2014-10-09  Joseph Myers  <joseph@codesourcery.com>
 
 	* gcc.dg/torture/float128-extendxf-underflow.c: New test.

gcc/testsuite/g++.dg/cpp0x/constexpr-compound.C

@@ -2,8 +2,8 @@
 
 constexpr int f()
 {
-  {				// { dg-error "" }
+  {				// { dg-error "compound-statement" "" { target { c++11_only } } }
     return 1;
   }
-  { }				// { dg-error "" }
+  { }				// { dg-error "compound-statement" "" { target { c++11_only } } }
 }

gcc/testsuite/g++.dg/cpp0x/constexpr-using3.C

+// { dg-do compile { target c++11 } }
+// { dg-options "-pedantic" }
+
+namespace ns { typedef int T; }
+
+constexpr int Test1(int x) { using ns::T; typedef T U; return U(x); }
+constexpr int Test2(int x) { using namespace ns; typedef T U; return U(x); }
+constexpr int Test3(int x) { { using ns::T; typedef T U; return U(x); } }  // { dg-warning "compound-statement" "" { target { c++11_only } } }
+constexpr int Test4(int x) { { using namespace ns; typedef T U; return T(x); } }  // { dg-warning "compound-statement" "" { target { c++11_only } } }
+
+struct S1
+{
+  constexpr S1() { using ns::T; typedef T U; }
+};
+
+struct S2
+{
+  constexpr S2() { using namespace ns; typedef T U; }
+};
+
+struct S3
+{
+  constexpr S3() { { using ns::T; typedef T U; } }  // { dg-warning "compound-statement" "" { target { c++11_only } } }
+};
+
+struct S4
+{
+  constexpr S4() { { using namespace ns; typedef T U; } }  // { dg-warning "compound-statement" "" { target { c++11_only } } }
+};

gcc/testsuite/g++.dg/cpp1y/constexpr-local-compound1.C

+// { dg-do compile { target c++14 } }
+
+#define SA(X) static_assert((X),#X)
+
+constexpr int f(int i) { { int j = i+1; return j; } }
+
+constexpr int i = f(41);
+
+struct S
+{
+  constexpr S() { { constexpr int j = 17; SA(j == 17); } }
+};
+
+SA(i==42);

gcc/testsuite/g++.dg/cpp1y/constexpr-local1.C

 // { dg-do compile { target c++14 } }
 
+#define SA(X) static_assert((X),#X)
+
 constexpr int f(int i) { int j = i+1; return j; }
 
 constexpr int i = f(41);
 
-#define SA(X) static_assert((X),#X)
+struct S
+{
+  constexpr S() { constexpr int j = 17; SA(j == 17); }
+};
 
 SA(i==42);

gcc/testsuite/g++.dg/cpp1y/constexpr-type-def-compound1.C

+// PR c++/55250
+// { dg-do compile { target c++14 } }
+
+#define SA(X) static_assert((X),#X)
+
+constexpr int Test1(int x) { { enum E { y = 1 }; return x + y; } }
+
+constexpr int Test2(int x) { { struct T { constexpr operator int() { return 1; } }; return x + T(); } }
+
+constexpr int Test3(int x) { { typedef enum E { y = 1 } EE; return x + EE::y; } }
+
+constexpr int Test4(int x) { { typedef struct T { constexpr operator int() { return 1; } } TT; return x + TT(); } }
+
+constexpr int Test5(int x) { { using EE = enum E { y = 1 }; return x + EE::y; } }
+
+constexpr int Test6(int x) { { using TT = struct T { constexpr operator int() { return 1; } }; return x + TT(); } }
+
+SA(Test1(2) == 3);
+SA(Test2(2) == 3);
+SA(Test3(2) == 3);
+SA(Test4(2) == 3);
+SA(Test5(2) == 3);
+SA(Test6(2) == 3);
+
+struct S1
+{
+  constexpr S1() { { enum E { y = 1 }; SA(y == 1); } }
+};
+
+struct S2
+{
+  constexpr S2() { { struct T { constexpr operator int() { return 1; } }; SA(T() == 1); } }
+};
+
+struct S3
+{
+  constexpr S3() { { typedef enum E { y = 1} EE; SA(EE::y == 1); } }
+};
+
+struct S4
+{
+  constexpr S4() { { typedef struct T { constexpr operator int() { return 1; } } TT; SA(TT() == 1); } }
+};
+
+struct S5
+{
+  constexpr S5() { { using EE = enum E { y = 1}; SA(EE::y == 1); } }
+};
+
+struct S6
+{
+  constexpr S6() { { using TT = struct T { constexpr operator int() { return 1; } }; SA(TT() == 1); } }
+};
+
+S1 s1;
+S2 s2;
+S3 s3;
+S4 s4;
+S5 s5;
+S6 s6;