On Wed, Mar 8, 2017 at 8:00 PM, Jason Merrill <ja...@redhat.com> wrote:
> In this testcase, ctx->object was the array subobject and 'this'
> refers to the containing object, so we failed. Fixed by generalizing
> PLACEHOLDER_EXPR handling more (in a way that replace_placeholders_r
> already handles).
A slight tweak:
commit a1737dce0a808b725f4da93b11c994d90a5878a9
Author: Jason Merrill <ja...@redhat.com>
Date: Thu Mar 16 11:57:14 2017 -0400
PR c++/79797
* constexpr.c (lookup_placeholder): Tweak.
diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index 2510e23e..4136b34 100644
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -3832,14 +3832,17 @@ cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t,
static tree
lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type)
{
- if (!ctx || !ctx->ctor || (lval && !ctx->object))
+ if (!ctx)
return NULL_TREE;
/* We could use ctx->object unconditionally, but using ctx->ctor when we
can is a minor optimization. */
- if (!lval && same_type_p (TREE_TYPE (ctx->ctor), type))
+ if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type))
return ctx->ctor;
+ if (!ctx->object)
+ return NULL_TREE;
+
/* Since an object cannot have a field of its own type, we can search outward
from ctx->object to find the unique containing object of TYPE. */
tree ob = ctx->object;
