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| author | Jesse Luehrs <doy@tozt.net> | 2012-06-26 21:12:18 -0500 |
|---|---|---|
| committer | Jesse Luehrs <doy@tozt.net> | 2012-06-28 03:06:08 -0500 |
| commit | 67288365cab33e76a48b697c001c11d4dc5b1912 (patch) | |
| tree | 8d612e9bb96382ad1b99581ae81e4f2a7356828b /pp.h | |
| parent | 591097e07a9ddfd1783a99ea394ab7e4113242b3 (diff) | |
| download | perl-67288365cab33e76a48b697c001c11d4dc5b1912.tar.gz | |
propagate context into overloads [perl #47119]
amagic_call now does its best to propagate the operator's context into
the overload callback. It's not always possible - for instance,
dereferencing and stringify/boolify/numify always have to return a
value, even if it's not used, due to the way the overload callback works
in those cases - but the majority of cases should now work. In
particular, overloading <> to handle list context properly is now
possible.
For backcompat reasons (amagic_call and friends are technically public
api functions), list context will not be propagated unless specifically
requested via the AMGf_want_list flag. If this is passed, and the
operator is called in list context, amagic_call returns an AV* holding
all of the returned values instead of an SV*. Void context always
results in amagic_call returning &PL_sv_undef.
Diffstat (limited to 'pp.h')
| -rw-r--r-- | pp.h | 35 |
1 files changed, 28 insertions, 7 deletions
@@ -397,6 +397,7 @@ Does not use C<TARG>. See also C<XPUSHu>, C<mPUSHu> and C<PUSHu>. #define AMGf_unary 8 #define AMGf_numeric 0x10 /* for Perl_try_amagic_bin */ #define AMGf_set 0x20 /* for Perl_try_amagic_bin */ +#define AMGf_want_list 0x40 /* do SvGETMAGIC on the stack args before checking for overload */ @@ -418,21 +419,41 @@ Does not use C<TARG>. See also C<XPUSHu>, C<mPUSHu> and C<PUSHu>. /* No longer used in core. Use AMG_CALLunary instead */ #define AMG_CALLun(sv,meth) AMG_CALLunary(sv, CAT2(meth,_amg)) -#define tryAMAGICunTARGET(meth, shift, jump) \ +#define tryAMAGICunTARGET(meth, shift, jump) \ + tryAMAGICunTARGET_flags(meth, shift, jump, 0) +#define tryAMAGICunTARGETlist(meth, shift, jump) \ + tryAMAGICunTARGET_flags(meth, shift, jump, AMGf_want_list) +#define tryAMAGICunTARGET_flags(meth, shift, jump, flags) \ STMT_START { \ - dATARGET; \ dSP; \ SV *tmpsv; \ SV *arg= sp[shift]; \ + int gimme = GIMME_V; \ if (SvAMAGIC(arg) && \ (tmpsv = amagic_call(arg, &PL_sv_undef, meth, \ - AMGf_noright | AMGf_unary))) { \ + flags | AMGf_noright | AMGf_unary))) { \ SPAGAIN; \ sp += shift; \ - sv_setsv(TARG, tmpsv); \ - if (opASSIGN) \ - sp--; \ - SETTARG; \ + if (gimme == G_VOID) { \ + (void)POPs; /* XXX ??? */ \ + } \ + else if ((flags & AMGf_want_list) && gimme == G_ARRAY) { \ + int i; \ + I32 len; \ + assert(SvTYPE(tmpsv) == SVt_PVAV); \ + len = av_len((AV *)tmpsv) + 1; \ + (void)POPs; /* get rid of the arg */ \ + EXTEND(sp, len); \ + for (i = 0; i < len; ++i) \ + PUSHs(av_shift((AV *)tmpsv)); \ + } \ + else { /* AMGf_want_scalar */ \ + dATARGET; /* just use the arg's location */ \ + sv_setsv(TARG, tmpsv); \ + if (opASSIGN) \ + sp--; \ + SETTARG; \ + } \ PUTBACK; \ if (jump) { \ OP *jump_o = NORMAL->op_next; \ |