re PR c++/78344 (ICE on invalid c++ code on x86_64-linux-gnu (internal compiler…

re PR c++/78344 (ICE on invalid c++ code on x86_64-linux-gnu (internal compiler error: tree check: expected tree_list, have error_mark in cp_check_const_attributes, at cp/decl2.c:1347))

/cp
2018-01-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/78344
	* decl.c (grokdeclarator): Do not append the error_mark_node
	due to an erroneous optional attribute-specifier-seq.

/testsuite
2018-01-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/78344
	* g++.dg/cpp0x/alignas13.C: New.

From-SVN: r256821

gcc/cp/ChangeLog

+2018-01-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/78344
+	* decl.c (grokdeclarator): Do not append the error_mark_node
+	due to an erroneous optional attribute-specifier-seq.
+
 2018-01-17  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/83897

gcc/cp/decl.c

@@ -11491,9 +11491,15 @@ grokdeclarator (const cp_declarator *declarator,
       && declarator->kind == cdk_id
       && declarator->std_attributes
       && attrlist != NULL)
-    /* [dcl.meaning]/1: The optional attribute-specifier-seq following
-       a declarator-id appertains to the entity that is declared.  */
-    *attrlist = chainon (*attrlist, declarator->std_attributes);
+    {
+      /* [dcl.meaning]/1: The optional attribute-specifier-seq following
+	 a declarator-id appertains to the entity that is declared.  */
+      if (declarator->std_attributes != error_mark_node)
+	*attrlist = chainon (*attrlist, declarator->std_attributes);
+      else
+	/* We should have already diagnosed the issue (c++/78344).  */
+	gcc_assert (seen_error ());
+    }
 
   /* Handle parameter packs. */
   if (parameter_pack_p)

gcc/testsuite/ChangeLog

+2018-01-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/78344
+	* g++.dg/cpp0x/alignas13.C: New.
+
 2018-01-17  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/83897

gcc/testsuite/g++.dg/cpp0x/alignas13.C

+// PR c++/78344
+// { dg-do compile { target c++11 } }
+
+alignas(double) int f alignas;         // { dg-error "30:expected '\\('" }
+alignas(double) int g alignas(double;  // { dg-error "37:expected '\\)'" }