Now that we allow unexpanded packs in a lambda, since they can be part
of the pattern of a pack expansion, we need to look at the argument
types when we scan the full-expression later.
But fixing this added an unexpected error to the test for 81060, where
we weren't properly diagnosing the unexpanded pack. Fixing that makes
the unexpected error go away.
I also noticed that the diagnostic location for the unexpanded pack in
the lambda was the trailing semicolon, which is suboptimal. This
turned out to be because EXPR_LOC_OR_LOC doesn't consider
LAMBDA_EXPR_LOCATION, because LAMBDA_EXPR is tcc_exceptional, not
EXPR_P. So I'm introducing cp_expr_loc_or_loc that handles
LAMBDA_EXPR as well.
I'm also changing the location of a LAMBDA_EXPR to be its full range,
rather than just the first [.
Tested x86_64-pc-linux-gnu, applying to trunk. First two patches also
applying to 8.
commit d9959931944e05e8d4d7db5a0f617d5a47ee2f1a
Author: Jason Merrill <ja...@redhat.com>
Date: Mon Jun 18 16:03:32 2018 -0400
PR c++/86200 - ICE with unexpanded pack in lambda parameter.
* pt.c (find_parameter_packs_r) [LAMBDA_EXPR]: Also look into the
function type.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 5af0f9afefc..b783b5e1436 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -3839,8 +3839,10 @@ find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
cap; cap = TREE_CHAIN (cap))
cp_walk_tree (&TREE_VALUE (cap), &find_parameter_packs_r, ppd,
ppd->visited);
- /* Since we defer implicit capture, look in the body as well. */
+ /* Since we defer implicit capture, look in the parms and body. */
tree fn = lambda_function (t);
+ cp_walk_tree (&TREE_TYPE (fn), &find_parameter_packs_r, ppd,
+ ppd->visited);
cp_walk_tree (&DECL_SAVED_TREE (fn), &find_parameter_packs_r, ppd,
ppd->visited);
*walk_subtrees = 0;
diff --git a/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-variadic7.C b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-variadic7.C
new file mode 100644
index 00000000000..c5355b0a8d8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-variadic7.C
@@ -0,0 +1,14 @@
+// PR c++/86200
+// { dg-do compile { target c++11 } }
+
+template<typename ... Args>
+static void foo()
+{
+ [](Args, int x) {
+ x;
+ }; // { dg-error "packs not expanded" }
+}
+int main()
+{
+ foo();
+}
