FFI: Allow indexing a struct constructor to get constants.

Specialize to the CTypeID held by a constructor in all cases.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/lj_cdata.c b/src/lj_cdata.c
index 5bd55237..1d0aea85 100644
--- a/src/lj_cdata.c
+++ b/src/lj_cdata.c
@@ -127,6 +127,17 @@ collect_attrib:
           return ct;
         }
       }
+    } else if (cd->typeid == CTID_CTYPEID) {
+      /* Allow indexing a (pointer to) struct constructor to get constants. */
+      CType *sct = ct = ctype_raw(cts, *(CTypeID *)p);
+      if (ctype_isptr(sct->info))
+        sct = ctype_rawchild(cts, sct);
+      if (ctype_isstruct(sct->info)) {
+        CTSize ofs;
+        CType *fct = lj_ctype_getfield(cts, sct, name, &ofs);
+        if (fct && ctype_isconstval(fct->info))
+          return fct;
+      }
     }
     {
       GCstr *s = lj_ctype_repr(cts->L, ctype_typeid(cts, ct), NULL);