* C++ PATCH for c++/38798 (auto f() -> struct A {})
@ 2009-10-17 6:51 Jason Merrill
2009-10-21 16:36 ` H.J. Lu
0 siblings, 1 reply; 3+ messages in thread
From: Jason Merrill @ 2009-10-17 6:51 UTC (permalink / raw)
To: gcc-patches List
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DR 770 clarified that we shouldn't try to parse a class or
enum-specifier in the context of a trailing return type. I've
implemented that with a flag passed down into cp_parser_type_specifier.
Tested x86_64-pc-linux-gnu, applied to trunk.
[-- Attachment #2: 38798.patch --]
[-- Type: text/x-patch, Size: 7979 bytes --]
commit 638569c50c4b6f6f3025ff5e00265eeabd495417
Author: jason <jason@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sat Oct 17 06:11:08 2009 +0000
PR c++/38798
* parser.c (CP_PARSER_FLAGS_NO_TYPE_DEFINITIONS): New.
(cp_parser_type_specifier): Don't try to parse a class-specifier
or enum-specifier in that case.
(cp_parser_trailing_type_id): New.
(cp_parser_late_return_type_opt): Call it.
(cp_parser_type_id_1): Add is_trailing_return parm.
(cp_parser_type_specifier_seq): Likewise.
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 5e37343..b9b53e5 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -1194,8 +1194,12 @@ enum
/* The construct is optional. If it is not present, then no error
should be issued. */
CP_PARSER_FLAGS_OPTIONAL = 0x1,
- /* When parsing a type-specifier, do not allow user-defined types. */
- CP_PARSER_FLAGS_NO_USER_DEFINED_TYPES = 0x2
+ /* When parsing a type-specifier, treat user-defined type-names
+ as non-type identifiers. */
+ CP_PARSER_FLAGS_NO_USER_DEFINED_TYPES = 0x2,
+ /* When parsing a type-specifier, do not try to parse a class-specifier
+ or enum-specifier. */
+ CP_PARSER_FLAGS_NO_TYPE_DEFINITIONS = 0x4
};
/* This type is used for parameters and variables which hold
@@ -1741,10 +1745,11 @@ static tree cp_parser_type_id
(cp_parser *);
static tree cp_parser_template_type_arg
(cp_parser *);
+static tree cp_parser_trailing_type_id (cp_parser *);
static tree cp_parser_type_id_1
- (cp_parser *, bool);
+ (cp_parser *, bool, bool);
static void cp_parser_type_specifier_seq
- (cp_parser *, bool, cp_decl_specifier_seq *);
+ (cp_parser *, bool, bool, cp_decl_specifier_seq *);
static tree cp_parser_parameter_declaration_clause
(cp_parser *);
static tree cp_parser_parameter_declaration_list
@@ -5795,6 +5800,7 @@ cp_parser_new_type_id (cp_parser* parser, tree *nelts)
= "types may not be defined in a new-type-id";
/* Parse the type-specifier-seq. */
cp_parser_type_specifier_seq (parser, /*is_condition=*/false,
+ /*is_trailing_return=*/false,
&type_specifier_seq);
/* Restore the old message. */
parser->type_definition_forbidden_message = saved_message;
@@ -8028,6 +8034,7 @@ cp_parser_condition (cp_parser* parser)
= "types may not be defined in conditions";
/* Parse the type-specifier-seq. */
cp_parser_type_specifier_seq (parser, /*is_condition==*/true,
+ /*is_trailing_return=*/false,
&type_specifiers);
/* Restore the saved message. */
parser->type_definition_forbidden_message = saved_message;
@@ -9669,6 +9676,7 @@ cp_parser_conversion_type_id (cp_parser* parser)
attributes = cp_parser_attributes_opt (parser);
/* Parse the type-specifiers. */
cp_parser_type_specifier_seq (parser, /*is_condition=*/false,
+ /*is_trailing_return=*/false,
&type_specifiers);
/* If that didn't work, stop. */
if (type_specifiers.type == error_mark_node)
@@ -11644,6 +11652,9 @@ cp_parser_type_specifier (cp_parser* parser,
switch (keyword)
{
case RID_ENUM:
+ if ((flags & CP_PARSER_FLAGS_NO_TYPE_DEFINITIONS))
+ goto elaborated_type_specifier;
+
/* Look for the enum-specifier. */
type_spec = cp_parser_enum_specifier (parser);
/* If that worked, we're done. */
@@ -11666,6 +11677,9 @@ cp_parser_type_specifier (cp_parser* parser,
case RID_CLASS:
case RID_STRUCT:
case RID_UNION:
+ if ((flags & CP_PARSER_FLAGS_NO_TYPE_DEFINITIONS))
+ goto elaborated_type_specifier;
+
/* Parse tentatively so that we can back up if we don't find a
class-specifier. */
cp_parser_parse_tentatively (parser);
@@ -12532,6 +12546,7 @@ cp_parser_enum_specifier (cp_parser* parser)
/* Parse the type-specifier-seq. */
cp_parser_type_specifier_seq (parser, /*is_condition=*/false,
+ /*is_trailing_return=*/false,
&type_specifiers);
/* At this point this is surely not elaborated type specifier. */
@@ -14422,7 +14437,7 @@ cp_parser_cv_qualifier_seq_opt (cp_parser* parser)
/* Parse a late-specified return type, if any. This is not a separate
non-terminal, but part of a function declarator, which looks like
- -> type-id
+ -> trailing-type-specifier-seq abstract-declarator(opt)
Returns the type indicated by the type-id. */
@@ -14440,7 +14455,7 @@ cp_parser_late_return_type_opt (cp_parser* parser)
/* Consume the ->. */
cp_lexer_consume_token (parser->lexer);
- return cp_parser_type_id (parser);
+ return cp_parser_trailing_type_id (parser);
}
/* Parse a declarator-id.
@@ -14493,13 +14508,15 @@ cp_parser_declarator_id (cp_parser* parser, bool optional_p)
Returns the TYPE specified. */
static tree
-cp_parser_type_id_1 (cp_parser* parser, bool is_template_arg)
+cp_parser_type_id_1 (cp_parser* parser, bool is_template_arg,
+ bool is_trailing_return)
{
cp_decl_specifier_seq type_specifier_seq;
cp_declarator *abstract_declarator;
/* Parse the type-specifier-seq. */
cp_parser_type_specifier_seq (parser, /*is_condition=*/false,
+ is_trailing_return,
&type_specifier_seq);
if (type_specifier_seq.type == error_mark_node)
return error_mark_node;
@@ -14537,12 +14554,17 @@ cp_parser_type_id_1 (cp_parser* parser, bool is_template_arg)
static tree cp_parser_type_id (cp_parser *parser)
{
- return cp_parser_type_id_1 (parser, false);
+ return cp_parser_type_id_1 (parser, false, false);
}
static tree cp_parser_template_type_arg (cp_parser *parser)
{
- return cp_parser_type_id_1 (parser, true);
+ return cp_parser_type_id_1 (parser, true, false);
+}
+
+static tree cp_parser_trailing_type_id (cp_parser *parser)
+{
+ return cp_parser_type_id_1 (parser, false, true);
}
/* Parse a type-specifier-seq.
@@ -14558,11 +14580,15 @@ static tree cp_parser_template_type_arg (cp_parser *parser)
If IS_CONDITION is true, we are at the start of a "condition",
e.g., we've just seen "if (".
+ If IS_TRAILING_RETURN is true, we are in a trailing-return-type,
+ i.e. we've just seen "->".
+
Sets *TYPE_SPECIFIER_SEQ to represent the sequence. */
static void
cp_parser_type_specifier_seq (cp_parser* parser,
bool is_condition,
+ bool is_trailing_return,
cp_decl_specifier_seq *type_specifier_seq)
{
bool seen_type_specifier = false;
@@ -14572,6 +14598,12 @@ cp_parser_type_specifier_seq (cp_parser* parser,
/* Clear the TYPE_SPECIFIER_SEQ. */
clear_decl_specs (type_specifier_seq);
+ /* In the context of a trailing return type, enum E { } is an
+ elaborated-type-specifier followed by a function-body, not an
+ enum-specifier. */
+ if (is_trailing_return)
+ flags |= CP_PARSER_FLAGS_NO_TYPE_DEFINITIONS;
+
/* Parse the type-specifiers and attributes. */
while (true)
{
@@ -17283,6 +17315,7 @@ cp_parser_exception_declaration (cp_parser* parser)
/* Parse the type-specifier-seq. */
cp_parser_type_specifier_seq (parser, /*is_condition=*/false,
+ /*is_trailing_return=*/false,
&type_specifiers);
/* If it's a `)', then there is no declarator. */
if (cp_lexer_next_token_is (parser->lexer, CPP_CLOSE_PAREN))
@@ -22056,6 +22089,7 @@ cp_parser_omp_for_loop (cp_parser *parser, tree clauses, tree *par_clauses)
cp_parser_parse_tentatively (parser);
cp_parser_type_specifier_seq (parser, /*is_condition=*/false,
+ /*is_trailing_return=*/false,
&type_specifiers);
if (cp_parser_parse_definitely (parser))
{
diff --git a/gcc/testsuite/g++.dg/cpp0x/trailing5.C b/gcc/testsuite/g++.dg/cpp0x/trailing5.C
new file mode 100644
index 0000000..b97d362
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/trailing5.C
@@ -0,0 +1,10 @@
+// PR c++/38798, DR 770
+// { dg-options -std=c++0x }
+
+struct A {};
+auto foo() -> struct A {}
+
+enum B {};
+auto bar() -> enum B {}
+
+auto baz() -> struct C {} {} // { dg-error "" }
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: C++ PATCH for c++/38798 (auto f() -> struct A {})
2009-10-17 6:51 C++ PATCH for c++/38798 (auto f() -> struct A {}) Jason Merrill
@ 2009-10-21 16:36 ` H.J. Lu
2009-10-21 21:43 ` Jason Merrill
0 siblings, 1 reply; 3+ messages in thread
From: H.J. Lu @ 2009-10-21 16:36 UTC (permalink / raw)
To: Jason Merrill; +Cc: gcc-patches List
On Fri, Oct 16, 2009 at 11:20 PM, Jason Merrill <jason@redhat.com> wrote:
> DR 770 clarified that we shouldn't try to parse a class or enum-specifier in
> the context of a trailing return type. I've implemented that with a flag
> passed down into cp_parser_type_specifier.
>
> Tested x86_64-pc-linux-gnu, applied to trunk.
>
Hi Jason,
You removed 4 testcases:
trunk/gcc/testsuite/g++.dg/cpp0x/auto12.C
trunk/gcc/testsuite/g++.dg/cpp0x/auto13.C
trunk/gcc/testsuite/g++.dg/cpp0x/auto6.C
trunk/gcc/testsuite/g++.dg/cpp0x/auto8.C
But there are no ChangeLog entries. Is that intentional?
Thanks.
--
H.J.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: C++ PATCH for c++/38798 (auto f() -> struct A {})
2009-10-21 16:36 ` H.J. Lu
@ 2009-10-21 21:43 ` Jason Merrill
0 siblings, 0 replies; 3+ messages in thread
From: Jason Merrill @ 2009-10-21 21:43 UTC (permalink / raw)
To: H.J. Lu; +Cc: gcc-patches List
On 10/21/2009 09:03 AM, H.J. Lu wrote:
> You removed 4 testcases:
I renamed them.
> But there are no ChangeLog entries. Is that intentional?
I'll add some.
Jason
^ permalink raw reply [flat|nested] 3+ messages in thread
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2009-10-21 16:36 ` H.J. Lu
2009-10-21 21:43 ` Jason Merrill
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