re PR c++/51184 (Abstract class in function return type)

/cp
2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51184
	* decl.c (grokdeclarator): Diagnose functions returning abstract
	class types as TYPENAME.
	* cp-tree.h (ABSTRACT_CLASS_TYPE_P): Add.
	* except.c (is_admissible_throw_operand_or_catch_parameter): Use it.
	* pt.c (tsubst): Likewise.
	* semantics.c (trait_expr_value): Likewise.

/testsuite
2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/51184
	* g++.dg/other/abstract4.C: New-

/cp
2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/40821
	* parser.c (cp_parser_attributes_opt): Enforce error checking of
	unbalanced parentheses in the presence of tentative parsing.

/testsuite
2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/40821
	* g++.dg/ext/attrib46.C: New.

From-SVN: r187720

gcc/cp/ChangeLog

+2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/51184
+	* decl.c (grokdeclarator): Diagnose functions returning abstract
+	class types as TYPENAME.
+	* cp-tree.h (ABSTRACT_CLASS_TYPE_P): Add.
+	* except.c (is_admissible_throw_operand_or_catch_parameter): Use it.
+	* pt.c (tsubst): Likewise.
+	* semantics.c (trait_expr_value): Likewise.
+
+2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/40821
+	* parser.c (cp_parser_attributes_opt): Enforce error checking of
+	unbalanced parentheses in the presence of tentative parsing.
+
 2012-05-17  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/39681

gcc/cp/cp-tree.h

@@ -1658,6 +1658,10 @@ struct GTY((variable_size)) lang_type {
 #define CLASSTYPE_PURE_VIRTUALS(NODE) \
   (LANG_TYPE_CLASS_CHECK (NODE)->pure_virtuals)
 
+/* Nonzero means that this type is an abstract class type.  */
+#define ABSTRACT_CLASS_TYPE_P(NODE) \
+  (CLASS_TYPE_P (NODE) && CLASSTYPE_PURE_VIRTUALS(NODE))
+
 /* Nonzero means that this type has an X() constructor.  */
 #define TYPE_HAS_DEFAULT_CONSTRUCTOR(NODE) \
   (LANG_TYPE_CLASS_CHECK (NODE)->h.has_default_ctor)

gcc/cp/decl.c

@@ -9194,6 +9194,11 @@ grokdeclarator (const cp_declarator *declarator,
 		error ("%qs declared as function returning an array", name);
 		return error_mark_node;
 	      }
+	    /* When decl_context == NORMAL we emit a better error message
+	       later in abstract_virtuals_error.  */
+	    if (decl_context == TYPENAME && ABSTRACT_CLASS_TYPE_P (type))
+	      error ("%qs declared as function returning an abstract "
+		     "class type", name);
 
 	    /* Pick up type qualifiers which should be applied to `this'.  */
 	    memfn_quals = declarator->u.function.qualifiers;

gcc/cp/except.c

@@ -974,7 +974,7 @@ is_admissible_throw_operand_or_catch_parameter (tree t, bool is_throw)
   /* 10.4/3 An abstract class shall not be used as a parameter type,
 	    as a function return type or as type of an explicit
 	    conversion.  */
-  else if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
+  else if (ABSTRACT_CLASS_TYPE_P (type))
     {
       if (is_throw)
 	error ("expression %qE of abstract class type %qT cannot "

gcc/cp/parser.c

@@ -20052,6 +20052,7 @@ cp_parser_attributes_opt (cp_parser* parser)
     {
       cp_token *token;
       tree attribute_list;
+      bool ok = true;
 
       /* Peek at the next token.  */
       token = cp_lexer_peek_token (parser->lexer);
@@ -20076,8 +20077,12 @@ cp_parser_attributes_opt (cp_parser* parser)
 	attribute_list = NULL;
 
       /* Look for the two `)' tokens.  */
-      cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN);
-      cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN);
+      if (!cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN))
+	ok = false;
+      if (!cp_parser_require (parser, CPP_CLOSE_PAREN, RT_CLOSE_PAREN))
+	ok = false;
+      if (!ok)
+	cp_parser_skip_to_end_of_statement (parser);
 
       /* Add these new attributes to the list.  */
       attributes = chainon (attributes, attribute_list);

gcc/cp/pt.c

@@ -11646,7 +11646,7 @@ tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
 	      error ("creating array of %qT", type);
 	    return error_mark_node;
 	  }
-	if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
+	if (ABSTRACT_CLASS_TYPE_P (type))
 	  {
 	    if (complain & tf_error)
 	      error ("creating array of %qT, which is an abstract class type",

gcc/cp/semantics.c

@@ -5441,7 +5441,7 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2)
       return type_has_virtual_destructor (type1);
 
     case CPTK_IS_ABSTRACT:
-      return (CLASS_TYPE_P (type1) && CLASSTYPE_PURE_VIRTUALS (type1));
+      return (ABSTRACT_CLASS_TYPE_P (type1));
 
     case CPTK_IS_BASE_OF:
       return (NON_UNION_CLASS_TYPE_P (type1) && NON_UNION_CLASS_TYPE_P (type2)

gcc/testsuite/ChangeLog

+2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/51184
+	* g++.dg/other/abstract4.C: New-
+
+2012-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/40821
+	* g++.dg/ext/attrib46.C: New.
+
 2012-05-21  Joseph Myers  <joseph@codesourcery.com>
 
 	PR c/53148

gcc/testsuite/g++.dg/ext/attrib46.C

+// PR c++/40821
+
+struct __attribute__((aligned(8)) S1 { int i; }; // { dg-error "expected" }
+struct __attribute__( aligned(8)  S2 { int i; }; // { dg-error "expected" }

gcc/testsuite/g++.dg/other/abstract4.C

+// PR c++/51184
+
+template<typename T>
+struct S { };
+
+template<typename T>
+void foo();
+
+struct Abs
+{
+  virtual void bar() = 0;
+};
+
+int main()
+{
+  S<Abs(int)> s;     // { dg-error "abstract" }
+  foo<Abs(int)>();   // { dg-error "abstract" }
+}