Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK
for trunk/14?
-- >8 --
Since the terms of a requires-clause are grammatically primary-expressions
rather than e.g. postfix-expressions, it seems we need to explicitly
handle and diagnose the case where a term parses to bare unresolved
unqualified-id, like cp_parser_postfix_expression does, since
cp_parser_primary_expression doesn't do so itself. Otherwise we fail to
reject the first three requires-clauses those below.
Note that the only users of primary-expression in the C++ grammar are
indeed postfix-expression and constraint-logical-and-expression, so it
seems not so surprising that we need this special handling here.
PR c++/99678
gcc/cp/ChangeLog:
* parser.cc (cp_parser_constraint_primary_expression): Reject
a bare unresolved unqualified-id.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/concepts-requires38.C: New test.
---
gcc/cp/parser.cc | 2 ++
gcc/testsuite/g++.dg/cpp2a/concepts-requires38.C | 14 ++++++++++++++
2 files changed, 16 insertions(+)
create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-requires38.C
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index bc4a2359153..0d59f7d2690 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -31496,6 +31496,8 @@ cp_parser_constraint_primary_expression (cp_parser
*parser, bool lambda_p)
}
if (pce == pce_ok)
{
+ if (idk == CP_ID_KIND_UNQUALIFIED && identifier_p (expr))
+ expr = unqualified_name_lookup_error (expr);
cp_lexer_commit_tokens (parser->lexer);
return finish_constraint_primary_expr (expr);
}
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-requires38.C
b/gcc/testsuite/g++.dg/cpp2a/concepts-requires38.C
new file mode 100644
index 00000000000..663195b79cc
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-requires38.C
@@ -0,0 +1,14 @@
+// PR c++/99678
+// { dg-do compile { target c++20 } }
+
+template<class T>
+void f1() requires undeclared_identifier; // { dg-error "not declared" }
+
+template<class T>
+void f2() requires true && undeclared_identifier; // { dg-error "not declared"
}
+
+template<class T>
+void f3() requires false || undeclared_identifier; // { dg-error "not
declared" }
+
+template<class T>
+void f4() requires undeclared_identifier(T{}); // { dg-error "must be enclosed
in parentheses" }
--
2.45.2.457.g8d94cfb545
