[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 --- Comment #13 from Rafael Avila de Espindola --- Thank you so much. I can confirm that scylla now builds with gcc master with just a few fixes on the scylla side (we build with -Werror). There is a couple of test failures. I will try to reduce those and open new bugs as appropriate.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 --- Comment #11 from CVS Commits --- The master branch has been updated by Patrick Palka : https://gcc.gnu.org/g:f9f166251f181ddcee64092d89aecbc1166ca706 commit r10-7932-gf9f166251f181ddcee64092d89aecbc1166ca706 Author: Patrick Palka Date: Thu Apr 23 17:29:55 2020 -0400 c++: Lambda in friend of constrained class [PR94645] In the testcase below, when grokfndecl processes the operator() decl for the lambda inside the friend function foo, processing_template_decl is rightly 1, but template_class_depth on the lambda's closure type incorrectly returns 0 instead of 1. Since processing_template_decl > template_class_depth, this makes grokfndecl think that the operator() has its own set of template arguments, and so we attach the innermost set of constraints -- those belonging to struct l -- to the operator() decl. We then get confused when checking constraints_satisfied_p on the operator() because it doesn't have template information and yet has constraints associated with it. This patch fixes template_class_depth to return the correct template nesting level in cases like these, in that when it hits a friend function it walks into the DECL_FRIEND_CONTEXT of the friend rather than into the CP_DECL_CONTEXT. gcc/cp/ChangeLog: PR c++/94645 * pt.c (template_class_depth): Walk into the DECL_FRIEND_CONTEXT of a friend declaration rather than into its CP_DECL_CONTEXT. gcc/testsuite/ChangeLog: PR c++/94645 * g++.dg/cpp2a/concepts-lambda6.C: New test.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 Patrick Palka changed: What|Removed |Added Resolution|--- |FIXED Status|ASSIGNED|RESOLVED --- Comment #12 from Patrick Palka --- Fixed.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 --- Comment #10 from Patrick Palka --- Oops, it turns out the ICEs I was seeing in the cmcstl2 testsuite with the change in #c9 were actually due to PR94719, which has since been fixed. The cmcstl2 testsuite now compiles fine with or without the change in #c9 FWIW.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 Jason Merrill changed: What|Removed |Added Assignee|unassigned at gcc dot gnu.org |jason at gcc dot gnu.org Status|NEW |ASSIGNED
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645
--- Comment #9 from Patrick Palka ---
Thanks for the reduced testcases.
The problem in #c8 seems to start in grokfndecl() when processing the
operator() of the lambda. During grokfndecl on the operator(),
processing_template_decl is 1 but template_class_depth is 0 (seems it should be
1 here?). So the condition for 'memtmpl' in
tree ctx = friendp ? current_class_type : ctype;
bool memtmpl = (processing_template_decl > template_class_depth (ctx));
is true for this non-templated lambda, but IIUC 'memtmpl' should be true only
if the declaration in question has its own set of template parameters, which is
not the case here.
Since memtmpl is true, we then attach the innermost constraints (belonging to
struct l) to this non-templated operator() via:
if (memtmpl)
tmpl_reqs = TEMPLATE_PARMS_CONSTRAINTS (current_template_parms);
tree ci = build_constraints (tmpl_reqs, decl_reqs);
...
set_constraints (decl, ci);
and thing goes downhill from there.
I tried fixing template_class_depth to return 1 in this case via
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -390,7 +390,12 @@ template_class_depth (tree type)
++depth;
if (DECL_P (type))
- type = CP_DECL_CONTEXT (type);
+ {
+ if (tree fctx = DECL_FRIEND_CONTEXT (type))
+ type = fctx;
+ else
+ type = CP_DECL_CONTEXT (type);
+ }
else if (LAMBDA_TYPE_P (type) && LAMBDA_TYPE_EXTRA_SCOPE (type))
type = LAMBDA_TYPE_EXTRA_SCOPE (type);
else
but this change causes a bunch of ICEs in the cmcstl2 testsuite.
It seems that the condition for 'memtmpl' needs adjusting, but I'm not sure
how.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645
--- Comment #8 from Rafael Avila de Espindola ---
The internal compiler error reduces to
struct unordered_map {
int cend() const noexcept;
};
template concept HasMapInterface = requires(a t) { t.cend(); };
template
requires HasMapInterface struct l {
friend void foo(l opt) {
([]() {})();
}
};
struct p {
static unordered_map map();
};
void g(l *y) { foo(*y); }
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 --- Comment #7 from Patrick Palka --- As in PR94597, I think the testcases here in #c0 and #c2 might be invalid as-is -- the requirement "t.cend;" should probably be "t.cend();", and we reject the former since r10-7554. With that minor change we successfully compile the reduced testcase, but we still get the same ICE with the original testcase.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 Patrick Palka changed: What|Removed |Added Status|ASSIGNED|NEW Assignee|ppalka at gcc dot gnu.org |unassigned at gcc dot gnu.org --- Comment #6 from Patrick Palka --- Oops, accidentally assigned myself this bug; unassigning.
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 Patrick Palka changed: What|Removed |Added Assignee|unassigned at gcc dot gnu.org |ppalka at gcc dot gnu.org Status|NEW |ASSIGNED CC||ppalka at gcc dot gnu.org
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 Martin Liška changed: What|Removed |Added Status|WAITING |NEW
[Bug c++/94645] [10 Regression][concepts] incorrect concept evaluation with decltype, plus internal error since r10-7554-gf1ad7bac76b66257
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94645 Martin Liška changed: What|Removed |Added CC||jason at gcc dot gnu.org Known to work||9.3.0 Known to fail||10.0 Summary|[10 Regression][concepts] |[10 Regression][concepts] |incorrect concept |incorrect concept |evaluation with decltype, |evaluation with decltype, |plus internal error |plus internal error since ||r10-7554-gf1ad7bac76b66257 --- Comment #5 from Martin Liška --- Sorry, you are right. Reproduced now, the error started with r10-7554-gf1ad7bac76b66257.
