From: Jason Merrill <jason@redhat.com>
Date: Fri, 30 Sep 2022 14:04:22 +0000 (-0400)
Subject: c++: fix broken conversion in coroutines
X-Git-Tag: basepoints/gcc-14~4067
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0143b277c9b17215ab3d4b361e1aef431799e813;p=thirdparty%2Fgcc.git

c++: fix broken conversion in coroutines

You can't use CONVERT_EXPR to convert between two class types.

VIEW_CONVERT_EXPR takes liberties with the C++ type system, but is probably
safe in this context.  Let's also only use it when the type isn't already
what we want.

gcc/cp/ChangeLog:

	* coroutines.cc (expand_one_await_expression): Change conversion
	to VIEW_CONVERT_EXPR.
	* cp-gimplify.cc (cp_genericize_r) [CONVERT_EXPR]: Add assert.
---

diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index eca01abcb7a6..60b846600b92 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -1728,7 +1728,10 @@ expand_one_await_expression (tree *stmt, tree *await_expr, void *d)
     }
   else
     {
-      r = build1_loc (loc, CONVERT_EXPR, void_coro_handle_type, suspend);
+      r = suspend;
+      if (!same_type_ignoring_top_level_qualifiers_p (susp_type,
+						      void_coro_handle_type))
+	r = build1_loc (loc, VIEW_CONVERT_EXPR, void_coro_handle_type, r);
       r = build2_loc (loc, INIT_EXPR, void_coro_handle_type, data->conthand, r);
       r = build1 (CONVERT_EXPR, void_type_node, r);
       append_to_statement_list (r, &body_list);
diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc
index b4599fc34d85..5d26e59d098a 100644
--- a/gcc/cp/cp-gimplify.cc
+++ b/gcc/cp/cp-gimplify.cc
@@ -1589,6 +1589,7 @@ cp_genericize_r (tree *stmt_p, int *walk_subtrees, void *data)
       break;
 
     case CONVERT_EXPR:
+      gcc_checking_assert (!AGGREGATE_TYPE_P (TREE_TYPE (stmt)));
       gcc_assert (!CONVERT_EXPR_VBASE_PATH (stmt));
       break;