Fix assertion failure with our subs and constants

The code path that looks up ‘our’ subs was not vivifying GVs in
the symbol table, and it was assuming that anything it found
would be a GV.

Constants created by ‘use constant’ are stored as simple scalar refs,
when possible, instead of GVs with CVs.

So GvCV() was called on an RV, and blew up.

$ ./miniperl -Ilib -Mfeature=lexical_subs -e 'our sub foo; BEGIN { delete $::{foo}; } use constant foo=>3; warn foo()'
The lexical_subs feature is experimental at -e line 1.
Assertion failed: (SvTYPE(_gvgp) == SVt_PVGV || SvTYPE(_gvgp) == SVt_PVLV), function Perl_yylex, file toke.c, line 6566.
Abort trap: 6

diff --git a/t/op/lexsub.t b/t/op/lexsub.t
index 1dfd953..efb5309 100644 (file)
--- a/t/op/lexsub.t
+++ b/t/op/lexsub.t
@@ -7,7 +7,7 @@ BEGIN {
     *bar::is = *is;
     *bar::like = *like;
 }
-plan 129;
+plan 130;
 
 # -------------------- Errors with feature disabled -------------------- #
 
@@ -88,6 +88,14 @@ sub bar::c { 43 }
   my $y = if if if;
   is $y, 42, 'our subs from other packages override all keywords';
 }
+# Interaction with ‘use constant’
+{
+  our sub const; # symtab now has an undefined CV
+  BEGIN { delete $::{const} } # delete symtab entry; pad entry still exists
+  use constant const => 3; # symtab now has a scalar ref
+  # inlining this used to fail an assertion (parentheses necessary):
+  is(const, 3, 'our sub pointing to "use constant" constant');
+}
 
 # -------------------- state -------------------- #
 

diff --git a/toke.c b/toke.c
index 4e7ae3b..98e4b7d 100644 (file)
--- a/toke.c
+++ b/toke.c
@@ -6563,7 +6563,7 @@ Perl_yylex(pTHX)
                    rv2cv_op =
                        newCVREF(OPpMAY_RETURN_CONSTANT<<8, const_op);
                    cv = lex
-                       ? GvCV(gv)
+                       ? isGV(gv) ? GvCV(gv) : (CV *)gv
                        : rv2cv_op_cv(rv2cv_op, RV2CVOPCV_RETURN_STUB);
                }