> and this in tsubst_lambda_expr that assumes iobj:
>
> /* Fix the type of 'this'. */
> fntype = build_memfn_type (fntype, type,
> type_memfn_quals (fntype),
> type_memfn_rqual (fntype));
Unfortunately, putting a condition on this had some unforeseen
consequences. I've been working on this about 8 hours today and I'm a
little defeated after discovering this.
commit 39ade88fa1632c659c5c4ed065fa2b62d16a8670
Author: Jason Merrill <ja...@redhat.com>
Date: Tue Jan 24 15:29:35 2023 -0500
c++: static lambda in template [PR108526]
tsubst_lambda_expr uses build_memfn_type to build a METHOD_TYPE for the new
lamba op(). This is not what we want for a C++23 static op(), but since we
also use that METHOD_TYPE to communicate the closure type down to
tsubst_function_decl, let's wait and turn it back at that point.
PR c++/108526
gcc/cp/ChangeLog:
gcc/cp/ChangeLog:
* pt.cc (tsubst_function_decl): Handle static lambda.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/static-operator-call5.C: New test.
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 2a4d03c5e47..51fc246ed71 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -14306,6 +14306,11 @@ tsubst_function_decl (tree t, tree args,
tsubst_flags_t complain,
tree ctx = closure ? closure : DECL_CONTEXT (t);
bool member = ctx && TYPE_P (ctx);
+ /* If this is a static lambda, remove the 'this' pointer added in
+ tsubst_lambda_expr now that we know the closure type. */
+ if (lambda_fntype && DECL_STATIC_FUNCTION_P (t))
+ lambda_fntype = static_fn_type (lambda_fntype);
+
I discovered this when I decided to try a static lambda to see if that
would help me narrow down my current problem. I was shocked to find out
it exhibited the exact same ICE I was trying to fix. So I was going to
go undo my changes one by one to see what it was, thankfully this was
the first one I tried, I undid the condition I put on it, and the crash
was gone.
Anyway, this has been my whole day so far, I am going to have to look
deeper to decide how exactly I fix this because I don't think this hack
that is in place at the moment is the right way to do it. The first
idea that comes to mind is modifying the decl_context of the call
operator, but I'm really not sure. I'm just going to take a break, eat
some pizza, and come back to this hopefully less defeated.
Alex
