Refactor implicit function template implementation and fix 58534, 58536, 58548, 58549 and 58637.

gcc/
	* tree.c (grow_tree_vec_stat): New function ...
	* tree.h (grow_tree_vec_stat) (grow_tree_vec): ... and its declaration
	and macro front-end.

gcc/cp/
	PR c++/58534
	PR c++/58536
	PR c++/58548
	PR c++/58549
	PR c++/58637
	* parser.h (struct cp_parser): New members implicit_template_parms,
	implicit_template_scope and auto_is_implicit_function_template_parm_p.
	* parser.c (add_implicit_template_parms): Refactor as ...
	(synthesize_implicit_template_parm): ... this to append a new template
	type parm to the current template parameter list (introducing a new list
	if necessary).  Removed push_deferring_access_checks.
	(finish_fully_implicit_template): Removed pop_deferring_access_checks.
	(cp_parser_new): Initialize new cp_parser members.
	(cp_parser_parameter_declaration_clause): Consider auto as implicit
	template parm when parsing a parameter declaration (unless parsing an
	explicit specialization).
	(cp_parser_parameter_declaration_list): Remove local
	implicit_template_parms counter and reset cp_parser implicit template
	state when complete.
	(cp_parser_lambda_expression): Reset implicit template cp_parser members
	whilst generating lambda class.
	(cp_parser_function_definition_after_declarator): Reset implicit
	template cp_parser members whilst parsing function definition.
	(make_generic_type_name): Respell '<autoN>' as 'auto:N' which works
	better with template diagnostics.
	(cp_parser_simple_type_specifier): Synthesize implicit template parm on
	parsing 'auto' if auto_is_implicit_function_template_parm_p and provide
	diagnostics ...
	* decl.c (grokdeclarator): ... that were previously done here.

gcc/testsuite/g++.dg/
	* cpp1y/pr58534.C: New testcase.
	* cpp1y/pr58536.C: New testcase.
	* cpp1y/pr58548.C: New testcase.
	* cpp1y/pr58549.C: New testcase.
	* cpp1y/pr58637.C: New testcase.

From-SVN: r204714

gcc/ChangeLog

+2013-11-12  Adam Butcher  <adam@jessamine.co.uk>
+
+	* tree.c (grow_tree_vec_stat): New function ...
+	* tree.h (grow_tree_vec_stat) (grow_tree_vec): ... and its declaration
+	and macro front-end.
+
 2013-11-12  Marek Polacek  <polacek@redhat.com>
 
 	* final.c (update_alignments): Initialize label to NULL_RTX.

gcc/cp/ChangeLog

+2013-11-12  Adam Butcher  <adam@jessamine.co.uk>
+
+	PR c++/58534
+	PR c++/58536
+	PR c++/58548
+	PR c++/58549
+	PR c++/58637
+	* parser.h (struct cp_parser): New members implicit_template_parms,
+	implicit_template_scope and auto_is_implicit_function_template_parm_p.
+	* parser.c (add_implicit_template_parms): Refactor as ...
+	(synthesize_implicit_template_parm): ... this to append a new template
+	type parm to the current template parameter list (introducing a new list
+	if necessary).  Removed push_deferring_access_checks.
+	(finish_fully_implicit_template): Removed pop_deferring_access_checks.
+	(cp_parser_new): Initialize new cp_parser members.
+	(cp_parser_parameter_declaration_clause): Consider auto as implicit
+	template parm when parsing a parameter declaration (unless parsing an
+	explicit specialization).
+	(cp_parser_parameter_declaration_list): Remove local
+	implicit_template_parms counter and reset cp_parser implicit template
+	state when complete.
+	(cp_parser_lambda_expression): Reset implicit template cp_parser members
+	whilst generating lambda class.
+	(cp_parser_function_definition_after_declarator): Reset implicit
+	template cp_parser members whilst parsing function definition.
+	(make_generic_type_name): Respell '<autoN>' as 'auto:N' which works
+	better with template diagnostics.
+	(cp_parser_simple_type_specifier): Synthesize implicit template parm on
+	parsing 'auto' if auto_is_implicit_function_template_parm_p and provide
+	diagnostics ...
+	* decl.c (grokdeclarator): ... that were previously done here.
+
 2013-11-12  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	PR c++/57734

gcc/cp/decl.c

@@ -10381,33 +10381,11 @@ grokdeclarator (const cp_declarator *declarator,
 
       if (type_uses_auto (type))
 	{
-	  if (template_parm_flag)
-	    {
-	      error ("template parameter declared %<auto%>");
-	      type = error_mark_node;
-	    }
-	  else if (decl_context == CATCHPARM)
-	    {
-	      error ("catch parameter declared %<auto%>");
-	      type = error_mark_node;
-	    }
-	  else if (current_class_type && LAMBDA_TYPE_P (current_class_type))
-	    {
-	      if (cxx_dialect < cxx1y)
-		pedwarn (location_of (type), 0,
-			 "use of %<auto%> in lambda parameter declaration "
-			 "only available with "
-			 "-std=c++1y or -std=gnu++1y");
-	    }
-	  else if (cxx_dialect < cxx1y)
-	    pedwarn (location_of (type), 0,
-		     "use of %<auto%> in parameter declaration "
-		     "only available with "
-		     "-std=c++1y or -std=gnu++1y");
+	  if (cxx_dialect >= cxx1y)
+	    error ("%<auto%> parameter not permitted in this context");
 	  else
-	    pedwarn (location_of (type), OPT_Wpedantic,
-		     "ISO C++ forbids use of %<auto%> in parameter "
-		     "declaration");
+	    error ("parameter declared %<auto%>");
+	  type = error_mark_node;
 	}
 
       /* A parameter declared as an array of T is really a pointer to T.

gcc/cp/parser.h

@@ -360,11 +360,30 @@ typedef struct GTY(()) cp_parser {
      data structure with everything needed for parsing the clauses.  */
   cp_omp_declare_simd_data * GTY((skip)) omp_declare_simd;
 
+  /* Nonzero if parsing a parameter list where 'auto' should trigger an implicit
+     template parameter.  */
+  bool auto_is_implicit_function_template_parm_p;
+
   /* TRUE if the function being declared was made a template due to its
      parameter list containing generic type specifiers (`auto' or concept
      identifiers) rather than an explicit template parameter list.  */
   bool fully_implicit_function_template_p;
 
+  /* Tracks the function's template parameter list when declaring a function
+     using generic type parameters.  This is either a new chain in the case of a
+     fully implicit function template or an extension of the function's existing
+     template parameter list.  This is tracked to optimize calls subsequent
+     calls to synthesize_implicit_template_parm during
+     cp_parser_parameter_declaration.  */
+  tree implicit_template_parms;
+
+  /* The scope into which an implicit template parameter list has been
+     introduced or an existing template parameter list is being extended with
+     implicit template paramaters.  In most cases this is the sk_function_parms
+     scope containing the use of a generic type.  In the case of an out-of-line
+     member definition using a generic type, it is the sk_class scope.  */
+  cp_binding_level* implicit_template_scope;
+
 } cp_parser;
 
 /* In parser.c  */

gcc/testsuite/ChangeLog

+2013-11-12  Adam Butcher  <adam@jessamine.co.uk>
+
+	PR c++/58534
+	PR c++/58536
+	PR c++/58548
+	PR c++/58549
+	PR c++/58637
+	* g++.dg/cpp1y/pr58534.C: New testcase.
+	* g++.dg/cpp1y/pr58536.C: New testcase.
+	* g++.dg/cpp1y/pr58548.C: New testcase.
+	* g++.dg/cpp1y/pr58549.C: New testcase.
+	* g++.dg/cpp1y/pr58637.C: New testcase.
+
 2013-11-12  Joseph Myers  <joseph@codesourcery.com>
 
 	* gcc.dg/c90-thread-local-1.c, gcc.dg/c99-thread-local-1.c,

gcc/testsuite/g++.dg/cpp1y/pr58534.C

+// { dg-do compile }
+// { dg-options "-std=gnu++1y" }
+
+// PR c++/58534
+
+template<typename> void foo(const auto&) {}
+
+template<typename, typename...T> void foo(const auto&, T...) {}
+

gcc/testsuite/g++.dg/cpp1y/pr58536.C

+// { dg-do compile }
+// { dg-options "-std=gnu++1y" }
+
+// PR c++/58536
+
+struct A
+{
+  A(auto);
+};
+
+A::A(auto) {}
+

gcc/testsuite/g++.dg/cpp1y/pr58548.C

+// { dg-do compile }
+// { dg-options "-std=gnu++1y" }
+
+// PR c++/58548
+
+void foo(auto)
+{
+  struct A { int i; };
+}
+

gcc/testsuite/g++.dg/cpp1y/pr58549.C

+// { dg-do compile }
+// { dg-options "-std=gnu++1y" }
+
+// PR c++/58549
+
+void foo(auto)
+{
+  void bar();
+}
+

gcc/testsuite/g++.dg/cpp1y/pr58637.C

+// { dg-do compile }
+// { dg-options "-std=gnu++1y" }
+
+// PR c++/58637
+
+template<> void foo(auto); // { dg-error "auto|not a template" }
+

gcc/tree.c

@@ -1864,6 +1864,28 @@ make_tree_vec_stat (int len MEM_STAT_DECL)
 
   return t;
 }
+
+/* Grow a TREE_VEC node to new length LEN.  */
+
+tree
+grow_tree_vec_stat (tree v, int len MEM_STAT_DECL)
+{
+  gcc_assert (TREE_CODE (v) == TREE_VEC);
+
+  int oldlen = TREE_VEC_LENGTH (v);
+  gcc_assert (len > oldlen);
+
+  int oldlength = (oldlen - 1) * sizeof (tree) + sizeof (struct tree_vec);
+  int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
+
+  record_node_allocation_statistics (TREE_VEC, length - oldlength);
+
+  v = (tree) ggc_realloc_stat (v, length PASS_MEM_STAT);
+
+  TREE_VEC_LENGTH (v) = len;
+
+  return v;
+}
 
 /* Return 1 if EXPR is the integer constant zero or a complex constant
    of zero.  */

gcc/tree.h

@@ -3430,6 +3430,11 @@ extern tree make_tree_binfo_stat (unsigned MEM_STAT_DECL);
 extern tree make_tree_vec_stat (int MEM_STAT_DECL);
 #define make_tree_vec(t) make_tree_vec_stat (t MEM_STAT_INFO)
 
+/* Grow a TREE_VEC.  */
+
+extern tree grow_tree_vec_stat (tree v, int MEM_STAT_DECL);
+#define grow_tree_vec(v, t) grow_tree_vec_stat (v, t MEM_STAT_INFO)
+
 /* Return the (unique) IDENTIFIER_NODE node for a given name.
    The name is supplied as a char *.  */