Although this is an Objective-C++ patch, I need to touch stuff outside
“objc local”
contexts, so think it needs review,
(this is a regression fix for all open branches).
Iain Sandoe <i...@sandoe.co.uk> wrote:
We were discussing proposed reflection splicing syntax - [:reflection:]
in SG7
which has some similarities with objective-c++ message syntax with unnamed
params.
This reminded me that we have a *very* long-standing regression against
objective-c++ where it is not able to handle unnamed message parameters (an
idiom used in practice).
Fixed as below.
tested on x86_64-darwin, x86_64-linux-gnu,
OK for master / open branches?
thanks
Iain
------
When we are parsing an Objective-C++ message, a colon is a valid
terminator for a assignment-expression. That is:
[receiver meth:x:x:x:x];
Is a valid, if somewhat unreadable, construction; corresponding
to a method declaration like:
- (id) meth:(id)arg0 :(id)arg1 :(id)arg2 :(id)arg3;
Where three of the message params have no name.
If fact, although it might be unintentional, Objective-C/C++ can
accept message selectors with all the parms unnamed (this applies
to the clang implementation too, which is taken as the reference
for the language).
For regular C++, the pattern x:x is not valid in that position an
an error is emitted with a fixit for the expected scope token.
If we simply made that error conditional on !c_c_dialect_objc()
that would regress Objective-C++ diagnostics for cases outside a
message selector, so we add a state flag for this.
gcc/cp/ChangeLog:
PR objc++/49070
* parser.c (cp_debug_parser): Add Objective-C++ message
state flag.
(cp_parser_nested_name_specifier_opt): Allow colon to
terminate an assignment-expression when parsing Objective-
C++ messages.
(cp_parser_objc_message_expression): Set and clear message
parsing state on entry and exit.
* parser.h (struct cp_parser): Add a context flag for
Objective-C++ message state.
gcc/testsuite/ChangeLog:
PR objc++/49070
* obj-c++.dg/pr49070.mm: New test.
* objc.dg/unnamed-parms.m: New test.
---
gcc/cp/parser.c | 8 ++++-
gcc/cp/parser.h | 4 +++
gcc/testsuite/obj-c++.dg/pr49070.mm | 52 +++++++++++++++++++++++++++
gcc/testsuite/objc.dg/unnamed-parms.m | 28 +++++++++++++++
4 files changed, 91 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/obj-c++.dg/pr49070.mm
create mode 100644 gcc/testsuite/objc.dg/unnamed-parms.m
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 70775792161..e5ba1dcffaa 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -572,6 +572,8 @@ cp_debug_parser (FILE *file, cp_parser *parser)
parser->colon_corrects_to_scope_p);
cp_debug_print_flag (file, "Colon doesn't start a class definition",
parser->colon_doesnt_start_class_def_p);
+ cp_debug_print_flag (file, "Parsing an Objective-C++ message context",
+ parser->objective_c_message_context_p);
if (parser->type_definition_forbidden_message)
fprintf (file, "Error message for forbidden type definitions: %s %s\n",
parser->type_definition_forbidden_message,
@@ -6622,7 +6624,9 @@ cp_parser_nested_name_specifier_opt (cp_parser
*parser,
if (token->type == CPP_COLON
&& parser->colon_corrects_to_scope_p
- && cp_lexer_peek_nth_token (parser->lexer, 3)->type == CPP_NAME)
+ && cp_lexer_peek_nth_token (parser->lexer, 3)->type == CPP_NAME
+ /* name:name is a valid sequence in an Objective C message. */
+ && !parser->objective_c_message_context_p)
{
gcc_rich_location richloc (token->location);
richloc.add_fixit_replace ("::");
@@ -32965,6 +32969,7 @@ cp_parser_objc_message_expression (cp_parser*
parser)
{
tree receiver, messageargs;
+ parser->objective_c_message_context_p = true;
location_t start_loc = cp_lexer_peek_token (parser->lexer)->location;
cp_lexer_consume_token (parser->lexer); /* Eat '['. */
receiver = cp_parser_objc_message_receiver (parser);
@@ -32981,6 +32986,7 @@ cp_parser_objc_message_expression (cp_parser*
parser)
location_t combined_loc = make_location (start_loc, start_loc, end_loc);
protected_set_expr_location (result, combined_loc);
+ parser->objective_c_message_context_p = false;
return result;
}
diff --git a/gcc/cp/parser.h b/gcc/cp/parser.h
index d587cf2404b..a468b6992ad 100644
--- a/gcc/cp/parser.h
+++ b/gcc/cp/parser.h
@@ -350,6 +350,10 @@ struct GTY(()) cp_parser {
is terminated by colon. */
bool colon_doesnt_start_class_def_p;
+ /* TRUE if we are parsing an objective c message, and ':' is permitted
+ to terminate an assignment-expression. */
+ bool objective_c_message_context_p;
+
/* If non-NULL, then we are parsing a construct where new type
definitions are not permitted. The string stored here will be
issued as an error message if a type is defined. */
diff --git a/gcc/testsuite/obj-c++.dg/pr49070.mm
b/gcc/testsuite/obj-c++.dg/pr49070.mm
new file mode 100644
index 00000000000..d67c72137cc
--- /dev/null
+++ b/gcc/testsuite/obj-c++.dg/pr49070.mm
@@ -0,0 +1,52 @@
+/* Only needs to compile. */
+/* { dg-additional-options "-std=c++11" } */
+
+#ifdef __cplusplus
+enum X {
+ x = 5,
+ y
+};
+#endif
+
+__attribute__((__objc_root_class__))
+@interface A
+- (id) :(id)arg0 :(id)arg1;
+- (id) m:(id)arg0 :(id)arg1 :(id)arg2 :(id)arg3;
+#ifdef __cplusplus
+- (id) n:(X)arg0 :(X)arg1 :(id)arg2 :(id)arg3;
+#endif
+@end
+
+@implementation A
+- (id) :(id)arg0 :(id)arg1
+{
+ return arg1;
+}
+- (id) m:(id)arg0 :(id)arg1 :(id)arg2 :(id)arg3
+{
+ return arg2;
+}
+#ifdef __cplusplus
+- (id) n:(X)arg0 :(X)arg1 :(id)arg2 :(id)arg3
+{
+ return arg2;
+}
+#endif
+@end
+
+id f1 (A *x)
+{
+ return [x:x:x];
+}
+
+id f2 (A *x)
+{
+ return [x m:x:x:x:x];
+}
+
+#ifdef __cplusplus
+id f3 (A *x)
+{
+ return [x n:X::x:X::y:x:x];
+}
+#endif
diff --git a/gcc/testsuite/objc.dg/unnamed-parms.m
b/gcc/testsuite/objc.dg/unnamed-parms.m
new file mode 100644
index 00000000000..22426cfed5f
--- /dev/null
+++ b/gcc/testsuite/objc.dg/unnamed-parms.m
@@ -0,0 +1,28 @@
+/* Only needs to compile [see PR 49070 for C++ issue]. */
+
+__attribute__((__objc_root_class__))
+@interface A
+- (id) :(id)arg0 :(id)arg1;
+- (id) m:(id)arg0 :(id)arg1 :(id)arg2 :(id)arg3;
+@end
+
+@implementation A
+- (id) :(id)arg0 :(id)arg1
+{
+ return arg1;
+}
+- (id) m:(id)arg0 :(id)arg1 :(id)arg2 :(id)arg3
+{
+ return arg2;
+}
+@end
+
+id f1 (A *x)
+{
+ return [x:x:x];
+}
+
+id f2 (A *x)
+{
+ return [x m:x:x:x:x];
+}
--
2.24.1
