PR c++/96329: ICE-on-invalid-code error recovery.

This patch fixes PR c++/96329 which is an ICE-on-invalid-code regression
affecting mainline.

2022-03-08  Roger Sayle  <roger@nextmovesoftware.com>

gcc/cp/ChangeLog
	PR c++/96329
	* parser.cc (cp_parser_linkage_specification): Treat the case where
	linkage is error_mark_node as "invalid linkage-specification".

gcc/testsuite/ChangeLog
	PR c++/96329
	* g++.dg/template/pr96329.C: New test case.

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 20aab5eb6b1568849bcde70a9bec8e22adfe3bc0..dc2d39a875122df7ff21083aabb90b8f3ca3b47a 100644 (file)
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -16148,8 +16148,9 @@ cp_parser_linkage_specification (cp_parser* parser, tree prefix_attr)
   /* Transform the literal into an identifier.  If the literal is a
      wide-character string, or contains embedded NULs, then we can't
      handle it as the user wants.  */
-  if (strlen (TREE_STRING_POINTER (linkage))
-      != (size_t) (TREE_STRING_LENGTH (linkage) - 1))
+  if (linkage == error_mark_node
+      || strlen (TREE_STRING_POINTER (linkage))
+        != (size_t) (TREE_STRING_LENGTH (linkage) - 1))
     {
       cp_parser_error (parser, "invalid linkage-specification");
       /* Assume C++ linkage.  */

diff --git a/gcc/testsuite/g++.dg/template/pr96329.C b/gcc/testsuite/g++.dg/template/pr96329.C
new file mode 100644 (file)
index 0000000..3664322
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/pr96329.C
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-excess-errors "" } */
+
+extern "C" ""a