fix #41654, layout of 0-field structs with circular supertypes (#41660)

JuliaLang · Jul 21, 2021 · b3a99c0 · b3a99c0
1 parent 69f8bce
commit b3a99c0
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/src/builtins.c b/src/builtins.c
@@ -1557,9 +1557,9 @@ JL_CALLABLE(jl_f__typebody)
  // able to compute the layout of the object before needing to
  // publish it, so we must assume it cannot be inlined, if that
  // check passes, then we also still need to check the fields too.
- if (!dt->name->mutabl && !references_name((jl_value_t*)dt->super, dt->name, 1)) {
+ if (!dt->name->mutabl && (nf == 0 || !references_name((jl_value_t*)dt->super, dt->name, 1))) {
  int mayinlinealloc = 1;
- size_t i, nf = jl_svec_len(ft);
+ size_t i;
  for (i = 0; i < nf; i++) {
  jl_value_t *fld = jl_svecref(ft, i);
  if (references_name(fld, dt->name, 1)) {

diff --git a/test/core.jl b/test/core.jl
@@ -7236,6 +7236,12 @@ end
 @test string((B40050(),)) == "($B40050(),)"
 @test_broken isbitstype(Tuple{B40050})
 
+# issue #41654
+struct X41654 <: Ref{X41654}
+end
+@test isbitstype(X41654)
+@test ('a'=>X41654(),)[1][2] isa X41654
+
 # Issue #34206/34207
 function mre34206(a, n)
  va = view(a, :)