diff options
Diffstat (limited to 'gv.c')
| -rw-r--r-- | gv.c | 47 |
1 files changed, 47 insertions, 0 deletions
@@ -2372,6 +2372,53 @@ Perl_gv_name_set(pTHX_ GV *gv, const char *name, U32 len, U32 flags) } /* +=for apidoc gv_try_downgrade + +If C<gv> is a typeglob containing only a constant sub, and is only +referenced from its package, and both the typeglob and the sub are +sufficiently ordinary, replace the typeglob (in the package) with a +placeholder that more compactly represents the same thing. This is meant +to be used when a placeholder has been upgraded, most likely because +something wanted to look at a proper code object, and it has turned out +to be a constant sub to which a proper reference is no longer required. + +=cut +*/ + +void +Perl_gv_try_downgrade(pTHX_ GV *gv) +{ + HV *stash; + CV *cv; + HEK *namehek; + SV **gvp; + PERL_ARGS_ASSERT_GV_TRY_DOWNGRADE; + if (SvREFCNT(gv) == 1 && SvTYPE(gv) == SVt_PVGV && !SvFAKE(gv) && + !SvOBJECT(gv) && !SvMAGICAL(gv) && !SvREADONLY(gv) && + isGV_with_GP(gv) && GvGP(gv) && + GvMULTI(gv) && !GvINTRO(gv) && GvREFCNT(gv) == 1 && + !GvSV(gv) && !GvAV(gv) && !GvHV(gv) && !GvIOp(gv) && !GvFORM(gv) && + GvEGV(gv) == gv && (stash = GvSTASH(gv)) && (cv = GvCV(gv)) && + !SvOBJECT(cv) && !SvMAGICAL(cv) && !SvREADONLY(cv) && + CvSTASH(cv) == stash && CvGV(cv) == gv && + CvCONST(cv) && !CvMETHOD(cv) && !CvLVALUE(cv) && !CvUNIQUE(cv) && + !CvNODEBUG(cv) && !CvCLONE(cv) && !CvCLONED(cv) && !CvANON(cv) && + (namehek = GvNAME_HEK(gv)) && + (gvp = hv_fetch(stash, HEK_KEY(namehek), + HEK_LEN(namehek)*(HEK_UTF8(namehek) ? -1 : 1), 0)) && + *gvp == (SV*)gv) { + SV *value = SvREFCNT_inc(CvXSUBANY(cv).any_ptr); + SvREFCNT(gv) = 0; + sv_clear((SV*)gv); + SvREFCNT(gv) = 1; + SvFLAGS(gv) = SVt_IV|SVf_ROK; + SvANY(gv) = (XPVGV*)((char*)&(gv->sv_u.svu_iv) - + STRUCT_OFFSET(XPVIV, xiv_iv)); + SvRV_set(gv, value); + } +} + +/* * Local variables: * c-indentation-style: bsd * c-basic-offset: 4 |