https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118630
Bug ID: 118630
Summary: [modules] ICE in sort_cluster when streaming
decltype(lambda) return type
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: nshead at gcc dot gnu.org
Blocks: 103524
Target Milestone: ---
The following sample:
export module M;
template <typename> decltype([]{}) f();
ICEs on current trunk when compiled with 'g++ -fmodules -std=c++20'.
It hits the checking-only assertion here (added in r15-4861):
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -14909,21 +14909,21 @@ sort_cluster (depset::hash *original, depset *scc[],
unsigned size)
{
gcc_checking_assert (order[ix]->is_special ());
bool tight = order[ix]->cluster == cluster;
depset *dep = order[ix]->deps[0];
dump (dumper::MERGE)
&& dump ("Mergeable %u is %N%s%s", ix, dep->get_entity (),
tight ? " (tight)" : "", dep->is_entry () ? " (entry)" : "");
scc[ix] = dep;
if (tight)
{
! gcc_checking_assert (dep->is_maybe_recursive ());
if (dep->is_entry ())
{
/* There should only be one entry dep in a cluster. */
gcc_checking_assert (!scc[entry_pos]->is_entry ());
gcc_checking_assert (scc[entry_pos]->is_maybe_recursive ());
scc[ix] = scc[entry_pos];
scc[entry_pos] = dep;
}
}
else
Without this assertion failure streaming seems to proceed correctly for this
specific case, but it's indicative of a potential underlying issue.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103524
[Bug 103524] [meta-bug] modules issue
