On 3/9/21 4:51 AM, Jakub Jelinek wrote:
Hi!
The r11-7528 build_co_await changes broke coroutines on arm*-linux-gnuabi,
2780 ^FAIL.*coroutines/ in total.
The problem is that arm is targetm.cxx.cdtor_return_this target where
both ctors and dtors in the ABI return this pointer rather than
void, and build_new_method_call_1 does:
else if (call != error_mark_node
&& DECL_DESTRUCTOR_P (cand->fn)
&& !VOID_TYPE_P (TREE_TYPE (call)))
/* An explicit call of the form "x->~X()" has type
"void". However, on platforms where destructors
return "this" (i.e., those where
targetm.cxx.cdtor_returns_this is true), such calls
will appear to have a return value of pointer type
to the low-level call machinery. We do not want to
change the low-level machinery, since we want to be
able to optimize "delete f()" on such platforms as
"operator delete(~X(f()))" (rather than generating
"t = f(), ~X(t), operator delete (t)"). */
call = build_nop (void_type_node, call);
The new code in build_co_await relies on build_special_member_call
returned expression being a CALL_EXPR, but due to the build_nop
in there it is a NOP_EXPR around the CALL_EXPR. It can't be stripped
with STRIP_NOPS because void has different mode from the pointer mode.
Bootstrapped/regtested on armv7hl-linux-gnueabi and x86_64-linux, ok for trunk?
thanks for digging into this. Looks good, but could you take the
opportunity to rewrite the conditionals to a single
if (dummy) { ... do the non-null things ... }
?
2021-03-09 Jakub Jelinek <ja...@redhat.com>
PR c++/99459
* coroutines.cc (build_co_await): Look through NOP_EXPRs in
build_special_member_call return value to find the CALL_EXPR.
--- gcc/cp/coroutines.cc.jj 2021-03-05 21:51:48.671185716 +0100
+++ gcc/cp/coroutines.cc 2021-03-08 10:53:13.187959339 +0100
@@ -868,6 +868,8 @@ build_co_await (location_t loc, tree a,
= build_special_member_call (a, complete_dtor_identifier,
NULL, a_type, LOOKUP_NORMAL,
tf_none);
+ if (dummy && CONVERT_EXPR_P (dummy))
+ dummy = TREE_OPERAND (dummy, 0);
dummy = dummy ? TREE_OPERAND (CALL_EXPR_FN (dummy), 0)
: NULL_TREE;
if (dummy && coro_diagnose_throwing_fn (dummy))
@@ -1031,6 +1033,8 @@ build_co_await (location_t loc, tree a,
= build_special_member_call (e_proxy, complete_dtor_identifier,
NULL, o_type, LOOKUP_NORMAL,
tf_none);
+ if (dummy && CONVERT_EXPR_P (dummy))
+ dummy = TREE_OPERAND (dummy, 0);
dummy = dummy ? TREE_OPERAND (CALL_EXPR_FN (dummy), 0)
: NULL_TREE;
if (dummy && coro_diagnose_throwing_fn (dummy))
Jakub
--
Nathan Sidwell
