splice-specifier < template-argument-list[opt] >
TEMPLATE_P is true if we've parsed the leading template keyword.
+ TYPENAME_P is true if we've parsed the leading typename keyword or are
+ in a type-only context.
TARGS_P is set to true if there is a splice-specialization-specifier. */
static cp_expr
cp_parser_splice_specifier (cp_parser *parser, bool template_p = false,
- bool *targs_p = nullptr)
+ bool typename_p = false, bool *targs_p = nullptr)
{
/* Get the location of the '[:'. */
location_t start_loc = cp_lexer_peek_token (parser->lexer)->location;
/* Get the reflected operand. */
expr = splice (expr);
- /* If the next token is a '<', it's a splice-specialization-specifier. */
- if (cp_lexer_next_token_is (parser->lexer, CPP_LESS))
+ /* If the next token is a <, it could be a splice-specialization-specifier.
+ But we need to handle "[:r:] < 42" where the < doesn't start a template
+ argument list. [temp.names]/3: A < is interpreted as the delimiter of
+ a template-argument-list if either
+ -- it follows a splice-specifier that either
+ -- appears in a type-only context or
+ -- is preceded by template or typename. */
+ if (cp_parser_nth_token_starts_template_argument_list_p (parser, 1)
+ /* As a courtesy to the user, if there is a < after a template
+ name, parse the construct as an s-s-s and warn about the missing
+ 'template'; it can't be anything else. */
+ && (template_p || typename_p || TREE_CODE (expr) == TEMPLATE_DECL))
{
/* For member access splice-specialization-specifier, try to wrap
non-dependent splice for function template into a BASELINK so
if (cp_lexer_next_token_is_keyword (parser->lexer, RID_TYPENAME))
cp_lexer_consume_token (parser->lexer);
- cp_expr expr = cp_parser_splice_specifier (parser);
+ cp_expr expr = cp_parser_splice_specifier (parser, /*template_p=*/false,
+ /*typename_p=*/true);
const location_t loc = (expr != error_mark_node
? expr.get_location () : input_location);
tree type = expr.get_value ();
parser->object_scope = NULL_TREE;
parser->qualifying_scope = NULL_TREE;
- cp_expr expr = cp_parser_splice_specifier (parser, template_p, &targs_p);
+ cp_expr expr = cp_parser_splice_specifier (parser, template_p,
+ /*typename_p=*/false, &targs_p);
/* And don't leave the scopes set, either. */
parser->scope = NULL_TREE;
return error_mark_node;
}
- if (parser->in_template_argument_list_p
- && !parser->greater_than_is_operator_p)
- {
- error_at (loc, "unparenthesized splice expression cannot be used as "
- "a template argument");
- return error_mark_node;
- }
-
/* Make sure this splice-expression produces an expression. */
if (!check_splice_expr (loc, expr.get_start (), t, address_p,
member_access_p, /*complain=*/true))
bool template_p)
{
bool targs_p = false;
- cp_expr scope = cp_parser_splice_specifier (parser, template_p, &targs_p);
+ cp_expr scope = cp_parser_splice_specifier (parser, template_p, typename_p,
+ &targs_p);
const location_t loc = scope.get_location ();
if (TREE_CODE (scope) == TYPE_DECL)
scope = TREE_TYPE (scope);
return scope;
}
-/* We know the next token is '[:' (optionally preceded by a template or
- typename) and we are wondering if a '::' follows right after the
- closing ':]', or after the possible '<...>' after the ':]'. Return
- true if yes, false otherwise. */
+/* Skip the whole splice-expression: the optional typename/template,
+ [:...:], and also the <...>, if present. Return true if we skipped
+ successfully. */
static bool
-cp_parser_splice_spec_is_nns_p (cp_parser *parser)
+cp_parser_skip_entire_splice_expr (cp_parser *parser)
{
- /* ??? It'd be nice to use saved_token_sentinel, but its rollback
- uses cp_lexer_previous_token, but we may be the first token in the
- file so there are no previous tokens. Sigh. */
- cp_lexer_save_tokens (parser->lexer);
-
if (cp_lexer_next_token_is_keyword (parser->lexer, RID_TYPENAME)
|| cp_lexer_next_token_is_keyword (parser->lexer, RID_TEMPLATE))
cp_lexer_consume_token (parser->lexer);
- bool ok = false;
+ if (cp_lexer_next_token_is_not (parser->lexer, CPP_OPEN_SPLICE))
+ return false;
+
size_t n = cp_parser_skip_balanced_tokens (parser, 1);
if (n != 1)
{
- ok = true;
/* Consume tokens up to the ':]' (including). */
for (n = n - 1; n; --n)
cp_lexer_consume_token (parser->lexer);
/* Consume the whole '<....>', if present. */
if (cp_lexer_next_token_is (parser->lexer, CPP_LESS)
&& !cp_parser_skip_entire_template_parameter_list (parser))
- ok = false;
+ return false;
- ok = ok && cp_lexer_next_token_is (parser->lexer, CPP_SCOPE);
+ return true;
}
+ return false;
+}
+
+/* We know the next token is '[:' (optionally preceded by a template or
+ typename) and we are wondering if a '::' follows right after the
+ closing ':]', or after the possible '<...>' after the ':]'. Return
+ true if yes, false otherwise. */
+
+static bool
+cp_parser_splice_spec_is_nns_p (cp_parser *parser)
+{
+ /* ??? It'd be nice to use saved_token_sentinel, but its rollback
+ uses cp_lexer_previous_token, but we may be the first token in the
+ file so there are no previous tokens. Sigh. */
+ cp_lexer_save_tokens (parser->lexer);
+
+ const bool ok = (cp_parser_skip_entire_splice_expr (parser)
+ && cp_lexer_next_token_is (parser->lexer, CPP_SCOPE));
+
/* Roll back the tokens we skipped. */
cp_lexer_rollback_tokens (parser->lexer);
error_at (token->location, "%qT is not a template", templ);
else
error_at (token->location, "%qE is not a template", templ);
+ pop_deferring_access_checks ();
return error_mark_node;
}
else
&& cp_lexer_next_token_is (parser->lexer, CPP_OPEN_BRACE))
return cp_parser_braced_list (parser);
+ /* [temp.names]/6: The constant-expression of a template-argument
+ shall not be an unparenthesized splice-expression. */
+ cp_token *next = nullptr;
+ if (flag_reflection)
+ {
+ saved_token_sentinel toks (parser->lexer, STS_ROLLBACK);
+ if (cp_parser_skip_entire_splice_expr (parser))
+ next = cp_lexer_peek_token (parser->lexer);
+ }
+
/* With C++17 generalized non-type template arguments we need to handle
lvalue constant expressions, too. */
argument = cp_parser_assignment_expression (parser);
+ if (UNLIKELY (cp_lexer_peek_token (parser->lexer) == next)
+ && argument != error_mark_node)
+ {
+ loc = cp_lexer_peek_token (parser->lexer)->location;
+ error_at (loc, "unparenthesized splice expression cannot be used "
+ "as a template argument");
+ return error_mark_node;
+ }
}
if (!maybe_type_id)
projects / thirdparty / gcc.git / commitdiff
