poplevel already tries to keep undeduced autos out of BLOCK_VARS, but
in this testcase cp_genericize_r was adding one in later on.
Tested x86_64-pc-linux-gnu, applying to trunk.
commit 61f3456c563fd7b3354a688f40c1afbfa8423442
Author: Jason Merrill <ja...@redhat.com>
Date: Fri Apr 6 07:45:01 2018 -0400
PR c++/85240 - LTO ICE with using of undeduced auto fn.
* cp-gimplify.c (cp_genericize_r): Discard using of undeduced auto.
diff --git a/gcc/cp/cp-gimplify.c b/gcc/cp/cp-gimplify.c
index fd0c37f9be2..fb0aea3e0c7 100644
--- a/gcc/cp/cp-gimplify.c
+++ b/gcc/cp/cp-gimplify.c
@@ -1294,16 +1294,20 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void *data)
}
if (block)
{
- tree using_directive;
- gcc_assert (TREE_OPERAND (stmt, 0));
+ tree decl = TREE_OPERAND (stmt, 0);
+ gcc_assert (decl);
- using_directive = make_node (IMPORTED_DECL);
- TREE_TYPE (using_directive) = void_type_node;
+ if (undeduced_auto_decl (decl))
+ /* Omit from the GENERIC, the back-end can't handle it. */;
+ else
+ {
+ tree using_directive = make_node (IMPORTED_DECL);
+ TREE_TYPE (using_directive) = void_type_node;
- IMPORTED_DECL_ASSOCIATED_DECL (using_directive)
- = TREE_OPERAND (stmt, 0);
- DECL_CHAIN (using_directive) = BLOCK_VARS (block);
- BLOCK_VARS (block) = using_directive;
+ IMPORTED_DECL_ASSOCIATED_DECL (using_directive) = decl;
+ DECL_CHAIN (using_directive) = BLOCK_VARS (block);
+ BLOCK_VARS (block) = using_directive;
+ }
}
/* The USING_STMT won't appear in GENERIC. */
*stmt_p = build1 (NOP_EXPR, void_type_node, integer_zero_node);
diff --git a/gcc/testsuite/g++.dg/cpp1y/auto-fn51.C b/gcc/testsuite/g++.dg/cpp1y/auto-fn51.C
new file mode 100644
index 00000000000..7e4f488458b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/auto-fn51.C
@@ -0,0 +1,9 @@
+// PR c++/85240
+// { dg-do compile { target c++14 } }
+
+auto foo();
+
+void bar()
+{
+ using ::foo;
+}
