c++: ICE with erroneous template redeclaration [PR106311]

Here we ICE trying to get DECL_SOURCE_LOCATION of the parm that happens
to be error_mark_node in this ill-formed test.  I kept running into this
while reducing code, so it'd be good to have it fixed.

	PR c++/106311

gcc/cp/ChangeLog:

	* pt.cc (redeclare_class_template): Check DECL_P before accessing
	DECL_SOURCE_LOCATION.

gcc/testsuite/ChangeLog:

	* g++.dg/template/redecl5.C: New test.

(cherry picked from commit 2333b58c9892667545d0c2c3ecd2d7b947197511)

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 80fadead0f74bc6295660178058b1cf8ac0cb5cc..bef31416fb773573e465509060e00959c352a044 100644 (file)
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -6315,7 +6315,10 @@ redeclare_class_template (tree type, tree parms, tree cons)
        {
          auto_diagnostic_group d;
          error ("template parameter %q+#D", tmpl_parm);
-         inform (DECL_SOURCE_LOCATION (parm), "redeclared here as %q#D", parm);
+         if (DECL_P (parm))
+           inform (DECL_SOURCE_LOCATION (parm), "redeclared here as %q#D", parm);
+         else
+           inform (input_location, "redeclared here");
          return false;
        }
 

diff --git a/gcc/testsuite/g++.dg/template/redecl5.C b/gcc/testsuite/g++.dg/template/redecl5.C
new file mode 100644 (file)
index 0000000..fb2d698
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/redecl5.C
@@ -0,0 +1,5 @@
+// PR c++/106311
+// { dg-do compile }
+
+template <typename, long> struct array; // { dg-error "template parameter" }
+template <typename, size_t X> struct array { }; // { dg-error "declared" }