re PR c++/12226 (g++ fails to enforce accessibility requirement for copy constructor)

	PR c++/12226
	* call.c (CHECK_COPY_CONSTRUCTOR_P): New macro.
	(reference_binding): Set it when appropriate.
	(build_temp): New function, split out from ...
	(convert_like_real): ... here.  Honor CHECK_COPY_CONSTRUCTOR_P.
	(initialize_reference): Likewise.

	PR c++/12226
	* g++.dg/init/copy7.c: New test.

	PR c++/12226
	* testsuite/27_io/basic_filebuf/4.cc: Remove use of invalid copy
	constructor.
	* testsuite/27_io/basic_fstream/4.cc: Likewise.
	* testsuite/27_io/basic_ifstream/4.cc: Likewise.
	* testsuite/27_io/basic_ios/4.cc: Likewise.
	* testsuite/27_io/basic_iostream/4.cc: Likewise.
	* testsuite/27_io/basic_istream/4.cc: Likewise.
	* testsuite/27_io/basic_istingstream/4.cc: Likewise.
	* testsuite/27_io/basic_ofstream/4.cc: Likewise.
	* testsuite/27_io/basic_ostream/4.cc: Likewise.
	* testsuite/27_io/basic_ostringstream/4.cc: Likewise.
	* testsuite/27_io/basic_stringbuf/5.cc: Likewise.
	* testsuite/27_io/basic_stringstream/4.cc: Likewise.

	PR c++/13536
	* parser.c (cp_parser): Add in_type_id_in_expr_p.
	(cp_parser_new): Initialize it.
	(cp_parser_postfix_expression): Set it.
	(cp_parser_sizeof_operand): Likewise.
	(cp_parser_parameteR_declaration): Do not commit early to tenative
	parsers when in_type_id_in_expr_p is set.

	PR c++/13536
	* g++.dg/parse/cast1.C: New test.

From-SVN: r75397

1 files changed, 79 insertions, 45 deletions

diff --git a/gcc/cp/call.c b/gcc/cp/call.c
index 5e75925..46ebca5 100644
--- a/gcc/cp/call.c
+++ b/gcc/cp/call.c
@@ -497,6 +497,10 @@ struct z_candidate GTY(()) {
    should be created to hold the result of the conversion.  */
 #define NEED_TEMPORARY_P(NODE) TREE_LANG_FLAG_4 (NODE)
 
+/* TRUE in an IDENTITY_CONV or BASE_CONV if the copy constructor must
+   be accessible, even though it is not being used.  */
+#define CHECK_COPY_CONSTRUCTOR_P(NODE) TREE_LANG_FLAG_5 (NODE)
+
 #define USER_CONV_CAND(NODE) WRAPPER_ZC (TREE_OPERAND (NODE, 1))
 #define USER_CONV_FN(NODE) (USER_CONV_CAND (NODE)->fn)
 
@@ -1176,7 +1180,9 @@ reference_binding (tree rto, tree rfrom, tree expr, int flags)
   if (CLASS_TYPE_P (from) && compatible_p)
     {
       conv = build1 (IDENTITY_CONV, from, expr);
-      return direct_reference_binding (rto, conv);
+      conv = direct_reference_binding (rto, conv);
+      CHECK_COPY_CONSTRUCTOR_P (TREE_OPERAND (conv, 0)) = 1;
+      return conv;
     }
 
   /* [dcl.init.ref]
@@ -3952,6 +3958,34 @@ enforce_access (tree basetype_path, tree decl)
   return true;
 }
 
+/* Initialize a temporary of type TYPE with EXPR.  The FLAGS are a
+   bitwise or of LOOKUP_* values.  If any errors are warnings are
+   generated, set *DIAGNOSTIC_FN to "error" or "warning",
+   respectively.  If no diagnostics are generated, set *DIAGNOSTIC_FN
+   to NULL.  */
+
+static tree
+build_temp (tree expr, tree type, int flags, 
+	    void (**diagnostic_fn)(const char *, ...))
+{
+  int savew, savee;
+
+  savew = warningcount, savee = errorcount;
+  expr = build_special_member_call (NULL_TREE, 
+				    complete_ctor_identifier,
+				    build_tree_list (NULL_TREE, expr), 
+				    TYPE_BINFO (type),
+				    flags);
+  if (warningcount > savew)
+    *diagnostic_fn = warning;
+  else if (errorcount > savee)
+    *diagnostic_fn = error;
+  else
+    *diagnostic_fn = NULL;
+  return expr;
+}
+	    
+
 /* Perform the conversions in CONVS on the expression EXPR.  FN and
    ARGNUM are used for diagnostics.  ARGNUM is zero based, -1
    indicates the `this' argument of a method.  INNER is nonzero when
@@ -3964,9 +3998,8 @@ static tree
 convert_like_real (tree convs, tree expr, tree fn, int argnum, int inner,
 		   bool issue_conversion_warnings)
 {
-  int savew, savee;
-
   tree totype = TREE_TYPE (convs);
+  void (*diagnostic_fn)(const char *, ...);
 
   if (ICS_BAD_FLAG (convs)
       && TREE_CODE (convs) != USER_CONV
@@ -4038,35 +4071,24 @@ convert_like_real (tree convs, tree expr, tree fn, int argnum, int inner,
 	if (IS_AGGR_TYPE (totype)
 	    && (inner >= 0 || !lvalue_p (expr)))
 	  {
-	    savew = warningcount, savee = errorcount;
-	    expr = build_special_member_call
-	      (NULL_TREE, complete_ctor_identifier,
-	       build_tree_list (NULL_TREE, expr), TYPE_BINFO (totype),
-	       /* Core issue 84, now a DR, says that we don't allow UDCs
-		  for these args (which deliberately breaks copy-init of an
-		  auto_ptr<Base> from an auto_ptr<Derived>).  */
-	       LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION);
-
-	    /* Tell the user where this failing constructor call came from.  */
-	    if (fn)
+	    expr = (build_temp 
+		    (expr, totype, 
+		     /* Core issue 84, now a DR, says that we don't
+			allow UDCs for these args (which deliberately
+			breaks copy-init of an auto_ptr<Base> from an
+			auto_ptr<Derived>).  */
+		     LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
+		     &diagnostic_fn));
+		    
+	    if (diagnostic_fn)
 	      {
-		if (warningcount > savew)
-		  warning
+		if (fn)
+		  diagnostic_fn 
 		    ("  initializing argument %P of `%D' from result of `%D'",
 		     argnum, fn, convfn);
-		else if (errorcount > savee)
-		  error
-		    ("  initializing argument %P of `%D' from result of `%D'",
-		     argnum, fn, convfn);
-	      }
-	    else
-	      {
-		if (warningcount > savew)
-		  warning ("  initializing temporary from result of `%D'",
-			      convfn);
-		else if (errorcount > savee)
-		  error ("  initializing temporary from result of `%D'",
-			    convfn);
+		else
+		 diagnostic_fn 
+		   ("  initializing temporary from result of `%D'",  convfn);
 	      }
 	    expr = build_cplus_new (totype, expr);
 	  }
@@ -4081,7 +4103,13 @@ convert_like_real (tree convs, tree expr, tree fn, int argnum, int inner,
       if (inner >= 0
 	  && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
 	expr = decl_constant_value (expr);
-      return expr;
+      if (CHECK_COPY_CONSTRUCTOR_P (convs))
+	/* Generate a temporary copy purely to generate the required
+	   diagnostics.  */
+	build_temp (build_dummy_object (totype), totype, 
+		    LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
+		    &diagnostic_fn);
+	return expr;
     case AMBIG_CONV:
       /* Call build_user_type_conversion again for the error.  */
       return build_user_type_conversion
@@ -4108,11 +4136,17 @@ convert_like_real (tree convs, tree expr, tree fn, int argnum, int inner,
 	{
 	  /* We are going to bind a reference directly to a base-class
 	     subobject of EXPR.  */
-	  tree base_ptr = build_pointer_type (totype);
-
+	  if (CHECK_COPY_CONSTRUCTOR_P (convs))
+	    /* Generate a temporary copy purely to generate the required
+	       diagnostics.  */
+	    build_temp (build_dummy_object (TREE_TYPE (expr)),
+			TREE_TYPE (expr),
+			LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
+			&diagnostic_fn);
 	  /* Build an expression for `*((base*) &expr)'.  */
 	  expr = build_unary_op (ADDR_EXPR, expr, 0);
-	  expr = perform_implicit_conversion (base_ptr, expr);
+	  expr = perform_implicit_conversion (build_pointer_type (totype), 
+					      expr);
 	  expr = build_indirect_ref (expr, "implicit conversion");
 	  return expr;
 	}
@@ -4120,18 +4154,10 @@ convert_like_real (tree convs, tree expr, tree fn, int argnum, int inner,
       /* Copy-initialization where the cv-unqualified version of the source
 	 type is the same class as, or a derived class of, the class of the
 	 destination [is treated as direct-initialization].  [dcl.init] */
-      savew = warningcount, savee = errorcount;
-      expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
-					build_tree_list (NULL_TREE, expr),
-					TYPE_BINFO (totype),
-					LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING);
-      if (fn)
-	{
-	  if (warningcount > savew)
-	    warning ("  initializing argument %P of `%D'", argnum, fn);
-	  else if (errorcount > savee)
-	    error ("  initializing argument %P of `%D'", argnum, fn);
-	}
+      expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
+			 &diagnostic_fn);
+      if (diagnostic_fn && fn)
+	diagnostic_fn ("  initializing argument %P of `%D'", argnum, fn);
       return build_cplus_new (totype, expr);
 
     case REF_BIND:
@@ -6205,6 +6231,14 @@ initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
 	 remember that the conversion was required.  */
       if (TREE_CODE (conv) == BASE_CONV && !NEED_TEMPORARY_P (conv))
 	{
+	  void (*diagnostic_fn) (const char *, ...);
+	  if (CHECK_COPY_CONSTRUCTOR_P (conv))
+	    /* Generate a temporary copy purely to generate the required
+	       diagnostics.  */
+	    build_temp (build_dummy_object (TREE_TYPE (expr)),
+			TREE_TYPE (expr),
+			LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
+			&diagnostic_fn);
 	  base_conv_type = TREE_TYPE (conv);
 	  conv = TREE_OPERAND (conv, 0);
 	}