[C++ PATCH] PR c++/92531 - ICE with noexcept(lambda).

[Jason Merrill]

This was failing because uses_template_parms didn't recognize LAMBDA_EXPR as
a kind of expression.  Instead of trying to enumerate all the different
varieties of expression and then aborting if what's left isn't
error_mark_node, let's handle error_mark_node and then assume anything else
is an expression.

Tested x86_64-pc-linux-gnu, applying to trunk.

        * pt.c (uses_template_parms): Don't try to enumerate all the
        expression cases.
---
 gcc/cp/pt.c                                     | 17 +++--------------
 gcc/testsuite/g++.dg/cpp1z/constexpr-lambda25.C |  7 +++++++
 2 files changed, 10 insertions(+), 14 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-lambda25.C

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 872f8ff8f52..1b3d07b1a52 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -10537,22 +10537,11 @@ uses_template_parms (tree t)
                   || uses_template_parms (TREE_CHAIN (t)));
   else if (TREE_CODE (t) == TYPE_DECL)
     dependent_p = dependent_type_p (TREE_TYPE (t));
-  else if (DECL_P (t)
-          || EXPR_P (t)
-          || TREE_CODE (t) == TEMPLATE_PARM_INDEX
-          || TREE_CODE (t) == OVERLOAD
-          || BASELINK_P (t)
-          || identifier_p (t)
-          || TREE_CODE (t) == TRAIT_EXPR
-          || TREE_CODE (t) == CONSTRUCTOR
-          || CONSTANT_CLASS_P (t))
+  else if (t == error_mark_node)
+    dependent_p = false;
+  else
     dependent_p = (type_dependent_expression_p (t)
                   || value_dependent_expression_p (t));
-  else
-    {
-      gcc_assert (t == error_mark_node);
-      dependent_p = false;
-    }
 
   processing_template_decl = saved_processing_template_decl;
 
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda25.C 
b/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda25.C
new file mode 100644
index 00000000000..74db03ff569
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-lambda25.C
@@ -0,0 +1,7 @@
+// PR c++/92531
+// { dg-do compile { target c++17 } }
+
+template <typename XK>
+void ky () noexcept ([]{}); // IFNDR
+// Optional error: void(*)() to bool conv in converted constant expression
+// { dg-prune-output "converted constant expression" }

base-commit: bf09d886a4be1031f7003073115af6cbc5575353
-- 
2.18.1