diff options
| -rw-r--r-- | pp_ctl.c | 3 | ||||
| -rw-r--r-- | pp_hot.c | 29 |
2 files changed, 30 insertions, 2 deletions
@@ -2337,8 +2337,7 @@ PP(pp_leavesublv) if (gimme == G_SCALAR) { if (CxLVAL(cx) && !ref) { /* Leave it as it is if we can. */ if (MARK <= SP) { - if ((SvPADTMP(TOPs) || SvREADONLY(TOPs)) && - !SvSMAGICAL(TOPs)) { + if ((SvPADTMP(TOPs) || SvREADONLY(TOPs))) { what = SvREADONLY(TOPs) ? (TOPs == &PL_sv_undef) ? "undef" : "a readonly value" : "a temporary"; @@ -3381,6 +3381,35 @@ S_leavesub_adjust_stacks(pTHX_ SV **base_sp, I32 gimme) SV *sv = *from_sp++; assert(PL_tmps_ix + nargs < PL_tmps_max); +#ifdef DEBUGGING + /* PADTMPs with container set magic shouldn't appear in the + * wild. This assert is more important for pp_leavesublv(), + * but by testing for it here, we're more likely to catch + * bad cases (what with :lvalue subs not being widely + * deployed). The two issues are that for something like + * sub :lvalue { $tied{foo} } + * or + * sub :lvalue { substr($foo,1,2) } + * pp_leavesublv() will croak if the sub returns a PADTMP, + * and currently functions like pp_substr() return a mortal + * rather than using their PADTMP when returning a PVLV. + * This is because the PVLV will hold a ref to $foo, + * so $foo would get delayed in being freed while + * the PADTMP SV remained in the PAD. + * So if this assert fails it means either: + * 1) there is pp code similar to pp_substr that is + * returning a PADTMP instead of a mortal, and probably + * needs fixing, or + * 2) pp_leavesub is making unwarranted assumptions + * about always croaking on a PADTMP + */ + if (SvPADTMP(sv) && SvSMAGICAL(sv)) { + MAGIC *mg; + for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) { + assert(PERL_MAGIC_TYPE_IS_VALUE_MAGIC(mg->mg_type)); + } + } +#endif if (SvTEMP(sv) && !SvMAGICAL(sv) && SvREFCNT(sv) == 1) { /* can optimise away the copy */ |