c++: Allow GNU attributes before lambda -> [PR90333]

In my 9.3/10 patch for 90333 I allowed attributes between [] and (), and
after the trailing return type, but not in the place that GCC 8 expected
them, and we've gotten several bug reports about that.  So let's allow them
there, as well.

gcc/cp/ChangeLog:

	PR c++/90333
	* parser.c (cp_parser_lambda_declarator_opt): Accept GNU attributes
	between () and ->.

gcc/testsuite/ChangeLog:

	PR c++/90333
	* g++.dg/ext/attr-lambda3.C: New test.

diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index d8e92ab0f415e9477612e0c2dac8bf2e285fb0d1..86b4033f0a00c6ac95902e6377b71c32646a50c8 100644 (file)
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -11088,7 +11088,12 @@ cp_parser_lambda_declarator_opt (cp_parser* parser, tree lambda_expr)
        = cp_parser_exception_specification_opt (parser, CP_PARSER_FLAGS_NONE,
                                                 quals);
 
-      std_attrs = cp_parser_std_attribute_spec_seq (parser);
+      /* GCC 8 accepted attributes here, and this is the place for standard
+        C++11 attributes that appertain to the function type.  */
+      if (cp_next_tokens_can_be_gnu_attribute_p (parser))
+       gnu_attrs = cp_parser_gnu_attributes_opt (parser);
+      else
+       std_attrs = cp_parser_std_attribute_spec_seq (parser);
 
       /* Parse optional trailing return type.  */
       if (cp_lexer_next_token_is (parser->lexer, CPP_DEREF))
@@ -11097,8 +11102,10 @@ cp_parser_lambda_declarator_opt (cp_parser* parser, tree lambda_expr)
           return_type = cp_parser_trailing_type_id (parser);
         }
 
+      /* Also allow GNU attributes at the very end of the declaration, the
+        usual place for GNU attributes.  */
       if (cp_next_tokens_can_be_gnu_attribute_p (parser))
-       gnu_attrs = cp_parser_gnu_attributes_opt (parser);
+       gnu_attrs = chainon (gnu_attrs, cp_parser_gnu_attributes_opt (parser));
 
       /* Parse optional trailing requires clause.  */
       trailing_requires_clause = cp_parser_requires_clause_opt (parser, false);

diff --git a/gcc/testsuite/g++.dg/ext/attr-lambda3.C b/gcc/testsuite/g++.dg/ext/attr-lambda3.C
new file mode 100644 (file)
index 0000000..71d1303
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/attr-lambda3.C
@@ -0,0 +1,4 @@
+// PR c++/90333
+// { dg-do compile { target c++11 } }
+
+auto x = []() __attribute__((always_inline)) -> int { return 0; };