Hi again,
eventually I'm back with sort-of a synthesis of the various ideas, thus
something I believe very close in spirit to my original RFC, but much
more direct, using CLASSTYPE_TI_ARGS (eh!) and Jason' helper. And I
managed to see that we want to vec_safe_truncate the unparsed entities -
better late than never.
Anyway, another round of testing is in progress (in v3), all good so far.
Cheers, Paolo.
////////////////////
/cp
2018-03-09 Jason Merrill <ja...@redhat.com>
Paolo Carlini <paolo.carl...@oracle.com>
PR c++/71169
PR c++/71832
* pt.c (any_erroneous_template_args_p): New.
* cp-tree.h (any_erroneous_template_args_p): Declare it.
* parser.c (cp_parser_class_specifier_1): Use it.
/testsuite
2018-03-09 Jason Merrill <ja...@redhat.com>
Paolo Carlini <paolo.carl...@oracle.com>
PR c++/71169
PR c++/71832
* g++.dg/cpp0x/pr71169.C: New.
* g++.dg/cpp0x/pr71169-2.C: Likewise.
* g++.dg/cpp0x/pr71832.C: Likewise.
Index: cp/cp-tree.h
===================================================================
--- cp/cp-tree.h (revision 258378)
+++ cp/cp-tree.h (working copy)
@@ -6558,6 +6558,7 @@ extern int processing_template_parmlist;
extern bool dependent_type_p (tree);
extern bool dependent_scope_p (tree);
extern bool any_dependent_template_arguments_p (const_tree);
+extern bool any_erroneous_template_args_p (const_tree);
extern bool dependent_template_p (tree);
extern bool dependent_template_id_p (tree, tree);
extern bool type_dependent_expression_p (tree);
Index: cp/parser.c
===================================================================
--- cp/parser.c (revision 258378)
+++ cp/parser.c (working copy)
@@ -22669,6 +22669,19 @@ cp_parser_class_specifier_1 (cp_parser* parser)
cp_default_arg_entry *e;
tree save_ccp, save_ccr;
+ if (type != error_mark_node
+ && CLASSTYPE_TEMPLATE_INFO (type)
+ && any_erroneous_template_args_p (CLASSTYPE_TI_ARGS (type)))
+ {
+ /* Skip default arguments, NSDMIs, etc, in order to improve
+ error recovery (c++/71169, c++/71832). */
+ vec_safe_truncate (unparsed_funs_with_default_args, 0);
+ vec_safe_truncate (unparsed_nsdmis, 0);
+ vec_safe_truncate (unparsed_classes, 0);
+ vec_safe_truncate (unparsed_funs_with_definitions, 0);
+ goto out;
+ }
+
/* In a first pass, parse default arguments to the functions.
Then, in a second pass, parse the bodies of the functions.
This two-phased approach handles cases like:
@@ -22745,6 +22758,7 @@ cp_parser_class_specifier_1 (cp_parser* parser)
else
vec_safe_push (unparsed_classes, type);
+ out:
/* Put back any saved access checks. */
pop_deferring_access_checks ();
Index: cp/pt.c
===================================================================
--- cp/pt.c (revision 258378)
+++ cp/pt.c (working copy)
@@ -25048,6 +25048,38 @@ any_dependent_template_arguments_p (const_tree arg
return false;
}
+/* Returns true if ARGS contains any errors. */
+
+bool
+any_erroneous_template_args_p (const_tree args)
+{
+ int i;
+ int j;
+
+ if (args && TREE_CODE (args) != TREE_VEC)
+ {
+ if (tree ti = get_template_info (args))
+ args = TI_ARGS (ti);
+ else
+ args = NULL_TREE;
+ }
+
+ if (!args)
+ return false;
+ if (args == error_mark_node)
+ return true;
+
+ for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
+ {
+ const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
+ for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
+ if (error_operand_p (TREE_VEC_ELT (level, j)))
+ return true;
+ }
+
+ return false;
+}
+
/* Returns TRUE if the template TMPL is type-dependent. */
bool
Index: testsuite/g++.dg/cpp0x/pr71169-2.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr71169-2.C (nonexistent)
+++ testsuite/g++.dg/cpp0x/pr71169-2.C (working copy)
@@ -0,0 +1,19 @@
+// { dg-do compile { target c++11 } }
+
+template <Preconditioner> class A { // { dg-error "declared" }
+ template <class = int> void m_fn1() {
+ m_fn1();
+ }
+};
+
+template<typename>
+struct B
+{
+ int f(int = 0) { return 0; }
+};
+
+int main()
+{
+ B<int> b;
+ return b.f();
+}
Index: testsuite/g++.dg/cpp0x/pr71169.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr71169.C (nonexistent)
+++ testsuite/g++.dg/cpp0x/pr71169.C (working copy)
@@ -0,0 +1,7 @@
+// { dg-do compile { target c++11 } }
+
+template <Preconditioner> class A { // { dg-error "declared" }
+ template <class = int> void m_fn1() {
+ m_fn1();
+ }
+};
Index: testsuite/g++.dg/cpp0x/pr71832.C
===================================================================
--- testsuite/g++.dg/cpp0x/pr71832.C (nonexistent)
+++ testsuite/g++.dg/cpp0x/pr71832.C (working copy)
@@ -0,0 +1,7 @@
+// { dg-do compile { target c++11 } }
+
+template < typename decltype (0) > struct A // { dg-error "expected|two or
more" }
+{
+ void foo () { baz (); }
+ template < typename ... S > void baz () {}
+};
