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perl/class.c
Richard Leach 4e66795307 Perl_newSVobject - adjusted for the default values 
`newSV_type(SVt_PVOBJ)` does the following initialization:
* `ObjectMAXFIELD(sv) = -1;`
* `ObjectFIELDS(sv) = NULL;`

This commit makes two changes to `Perl_newSVobject` reflecting that:

1. There's no need for `Perl_newSVobject` to set either of these fields
if `fieldcount` is zero, so that line is coverted into a DEBUGGING
assert()` and one added for `ObjectMAXFIELD(sv)` for completeness.

2. When `fieldcount` is non-zero, setting `ObjectMAXFIELD(sv)` prior to
the `Newx()` is more likely to result in the compiler realising that
it only needs to do one `ObjectMAXFIELD(sv)` STORE rather than two.
2025-10-10 23:39:56 +01:00

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/* class.c
*
* Copyright (C) 2022 by Paul Evans and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
*
*/
/* This file contains the code that implements perl's new `use feature 'class'`
* object model
*/
#include "EXTERN.h"
#define PERL_IN_CLASS_C
#include "perl.h"
#include "XSUB.h"
enum {
PADIX_SELF = 1,
PADIX_PARAMS = 2,
};
void
Perl_croak_kw_unless_class(pTHX_ const char *kw)
{
PERL_ARGS_ASSERT_CROAK_KW_UNLESS_CLASS;
if(!HvSTASH_IS_CLASS(PL_curstash))
croak("Cannot '%s' outside of a 'class'", kw);
}
#define newSVobject(fieldcount) Perl_newSVobject(aTHX_ fieldcount)
SV *
Perl_newSVobject(pTHX_ Size_t fieldcount)
{
SV *sv = newSV_type(SVt_PVOBJ);
if (fieldcount) {
ObjectMAXFIELD(sv) = fieldcount - 1;
Newx(ObjectFIELDS(sv), fieldcount, SV *);
Zero(ObjectFIELDS(sv), fieldcount, SV *);
}
#ifdef DEBUGGING
else {
assert(!ObjectFIELDS(sv));
assert(ObjectMAXFIELD(sv) == -1);
}
#endif
return sv;
}
PP(pp_initfield)
{
UNOP_AUX_item *aux = cUNOP_AUX->op_aux;
SV *self = PAD_SVl(PADIX_SELF);
assert(SvTYPE(SvRV(self)) == SVt_PVOBJ);
SV *instance = SvRV(self);
SV **fields = ObjectFIELDS(instance);
PADOFFSET fieldix = aux[0].uv;
SV *val = NULL;
switch(PL_op->op_private & (OPpINITFIELD_AV|OPpINITFIELD_HV)) {
case 0:
if(PL_op->op_flags & OPf_STACKED) {
val = newSVsv(*PL_stack_sp);
rpp_popfree_1();
}
else
val = newSV(0);
break;
case OPpINITFIELD_AV:
{
AV *av;
if(PL_op->op_flags & OPf_STACKED) {
SV **svp = PL_stack_base + POPMARK + 1;
STRLEN count = PL_stack_sp - svp + 1;
av = newAV_alloc_x(count);
while(svp <= PL_stack_sp) {
av_push_simple(av, newSVsv(*svp));
svp++;
}
rpp_popfree_to(PL_stack_sp - count);
}
else
av = newAV();
val = (SV *)av;
break;
}
case OPpINITFIELD_HV:
{
HV *hv = newHV();
if(PL_op->op_flags & OPf_STACKED) {
SV **svp = PL_stack_base + POPMARK + 1;
STRLEN svcount = PL_stack_sp - svp + 1;
if(svcount % 2)
warner(packWARN(WARN_MISC), "Odd number of elements in hash field initialization");
while(svp <= PL_stack_sp) {
SV *key = *svp; svp++;
SV *val = svp <= PL_stack_sp ? *svp : &PL_sv_undef; svp++;
(void)hv_store_ent(hv, key, newSVsv(val), 0);
}
rpp_popfree_to(PL_stack_sp - svcount);
}
val = (SV *)hv;
break;
}
}
fields[fieldix] = val;
PADOFFSET padix = PL_op->op_targ;
if(padix) {
SAVESPTR(PAD_SVl(padix));
SV *sv = PAD_SVl(padix) = SvREFCNT_inc(val);
save_freesv(sv);
}
return NORMAL;
}
XS(injected_constructor);
XS(injected_constructor)
{
dXSARGS;
HV *stash = CvSTASH(cv);
assert(HvSTASH_IS_CLASS(stash));
struct xpvhv_aux *aux = HvAUX(stash);
if((items - 1) % 2)
warn("Odd number of arguments passed to %" HvNAMEf_QUOTEDPREFIX " constructor",
HvNAMEfARG(stash));
if (!aux->xhv_class_initfields_cv) {
croak("Cannot create an object of incomplete class %" HvNAMEf_QUOTEDPREFIX,
HvNAMEfARG(stash));
}
HV *params = NULL;
{
/* Set up params HV */
params = newHV();
SAVEFREESV((SV *)params);
for(SSize_t i = 1; i < items; i += 2) {
SV *name = ST(i);
SV *val = (i+1 < items) ? ST(i+1) : &PL_sv_undef;
/* TODO: think about sanity-checking name for being
* defined
* not ref (but overloaded objects?? boo)
* not duplicate
* But then, %params = @_; wouldn't do that
*/
(void)hv_store_ent(params, name, SvREFCNT_inc(val), 0);
}
}
SV *instance = newSVobject(aux->xhv_class_next_fieldix);
SvOBJECT_on(instance);
SvSTASH_set(instance, HvREFCNT_inc_simple(stash));
SV *self = sv_2mortal(newRV_noinc(instance));
PUSHSTACKi(PERLSI_CONSTRUCTOR);
assert(aux->xhv_class_initfields_cv);
{
ENTER;
SAVETMPS;
EXTEND(SP, 2);
PUSHMARK(SP);
PUSHs(self);
if(params)
PUSHs((SV *)params); // yes a raw HV
else
PUSHs(&PL_sv_undef);
PUTBACK;
call_sv((SV *)aux->xhv_class_initfields_cv, G_VOID);
SPAGAIN;
FREETMPS;
LEAVE;
}
if(aux->xhv_class_adjust_blocks) {
CV **cvp = (CV **)AvARRAY(aux->xhv_class_adjust_blocks);
U32 nblocks = av_count(aux->xhv_class_adjust_blocks);
for(U32 i = 0; i < nblocks; i++) {
ENTER;
SAVETMPS;
SPAGAIN;
EXTEND(SP, 2);
PUSHMARK(SP);
PUSHs(self); /* I don't believe this needs to be an sv_mortalcopy() */
PUTBACK;
call_sv((SV *)cvp[i], G_VOID);
SPAGAIN;
FREETMPS;
LEAVE;
}
}
POPSTACK;
SPAGAIN;
if(params && hv_iterinit(params) > 0) {
/* TODO: consider sorting these into a canonical order, but that's awkward */
HE *he = hv_iternext(params);
SV *paramnames = newSVsv(HeSVKEY_force(he));
SAVEFREESV(paramnames);
while((he = hv_iternext(params)))
sv_catpvf(paramnames, ", %" SVf, SVfARG(HeSVKEY_force(he)));
croak("Unrecognised parameters for %" HvNAMEf_QUOTEDPREFIX " constructor: %" SVf,
HvNAMEfARG(stash), SVfARG(paramnames));
}
EXTEND(SP, 1);
ST(0) = self;
XSRETURN(1);
}
/* OP_METHSTART is an UNOP_AUX whose AUX list contains
* [0].uv = count of fieldbinding pairs
* [1].uv = maximum fieldidx found in the binding list
* [...] = pairs of (padix, fieldix) to bind in .uv fields
*/
/* TODO: People would probably expect to find this in pp.c ;) */
PP(pp_methstart)
{
bool self_in_pad = PL_op->op_private & OPpSELF_IN_PAD;
SV *self;
if (self_in_pad)
self = PAD_SVl(PADIX_SELF);
else
/* note that if AvREAL(@_), be careful not to leak self:
* so keep it in @_ for now, and only shift it later */
self = *(av_fetch(GvAV(PL_defgv), 0, 1));
SV *rv = NULL;
/* pp_methstart happens before the first OP_NEXTSTATE of the method body,
* meaning PL_curcop still points at the callsite. This is useful for
* croak() messages. However, it means we have to find our current stash
* via a different technique.
*/
CV *curcv;
if(LIKELY(CxTYPE(CX_CUR()) == CXt_SUB))
curcv = CX_CUR()->blk_sub.cv;
else
curcv = find_runcv(NULL);
if(!SvROK(self) ||
!SvOBJECT((rv = SvRV(self))) ||
SvTYPE(rv) != SVt_PVOBJ) {
HEK *namehek = CvGvNAME_HEK(curcv);
croak(
namehek ? "Cannot invoke method %" HEKf_QUOTEDPREFIX " on a non-instance" :
"Cannot invoke method on a non-instance",
namehek);
}
if(CvSTASH(curcv) != SvSTASH(rv) &&
!sv_derived_from_hv(self, CvSTASH(curcv)))
croak("Cannot invoke a method of %" HvNAMEf_QUOTEDPREFIX " on an instance of %" HvNAMEf_QUOTEDPREFIX,
HvNAMEfARG(CvSTASH(curcv)), HvNAMEfARG(SvSTASH(rv)));
if (!self_in_pad) {
save_clearsv(&PAD_SVl(PADIX_SELF));
sv_setsv(PAD_SVl(PADIX_SELF), self);
}
UNOP_AUX_item *aux = cUNOP_AUX->op_aux;
if(aux) {
assert(SvTYPE(SvRV(self)) == SVt_PVOBJ);
SV *instance = SvRV(self);
SV **fieldp = ObjectFIELDS(instance);
U32 fieldcount = (aux++)->uv;
U32 max_fieldix = (aux++)->uv;
assert((U32)(ObjectMAXFIELD(instance)+1) > max_fieldix);
PERL_UNUSED_VAR(max_fieldix);
for(Size_t i = 0; i < fieldcount; i++) {
PADOFFSET padix = (aux++)->uv;
U32 fieldix = (aux++)->uv;
/* Defend against fields that don't yet exist; e.g. because of
* method invoked during DESTROY of an aborted constructor
* See also https://github.com/Perl/perl5/issues/22278
*/
if(fieldp[fieldix]) {
/* TODO: There isn't a convenient SAVE macro for doing both these
* steps in one go. Add one. */
SAVESPTR(PAD_SVl(padix));
SV *sv = PAD_SVl(padix) = SvREFCNT_inc(fieldp[fieldix]);
save_freesv(sv);
}
}
}
if (!self_in_pad) {
/* safe to shift and free self now */
self = av_shift(GvAV(PL_defgv));
if (AvREAL(GvAV(PL_defgv)))
SvREFCNT_dec_NN(self);
}
if(PL_op->op_private & OPpINITFIELDS) {
SV *params = *av_fetch(GvAV(PL_defgv), 0, 0);
if(params && SvTYPE(params) == SVt_PVHV) {
SAVESPTR(PAD_SVl(PADIX_PARAMS));
PAD_SVl(PADIX_PARAMS) = SvREFCNT_inc(params);
save_freesv(params);
}
}
return NORMAL;
}
static void
invoke_class_seal(pTHX_ void *arg_)
{
class_seal_stash((HV *)arg_);
}
void
Perl_class_setup_stash(pTHX_ HV *stash)
{
PERL_ARGS_ASSERT_CLASS_SETUP_STASH;
assert(HvHasAUX(stash));
if(HvSTASH_IS_CLASS(stash)) {
croak("Cannot reopen existing class %" HvNAMEf_QUOTEDPREFIX,
HvNAMEfARG(stash));
}
{
SV *isaname = newSVpvf("%" HEKf "::ISA", HvNAME_HEK(stash));
sv_2mortal(isaname);
AV *isa = get_av(SvPV_nolen(isaname), (SvFLAGS(isaname) & SVf_UTF8));
if(isa && av_count(isa) > 0)
croak("Cannot create class %" HEKf " as it already has a non-empty @ISA",
HvNAME_HEK(stash));
}
char *classname = HvNAME(stash);
U32 nameflags = HvNAMEUTF8(stash) ? SVf_UTF8 : 0;
/* TODO:
* Set some kind of flag on the stash to point out it's a class
* Allocate storage for all the extra things a class needs
* See https://github.com/leonerd/perl5/discussions/1
*/
/* Inject the constructor */
{
SV *newname = Perl_newSVpvf(aTHX_ "%s::new", classname);
SAVEFREESV(newname);
CV *newcv = newXS_flags(SvPV_nolen(newname), injected_constructor, __FILE__, NULL, nameflags);
CvSTASH_set(newcv, stash);
}
/* TODO:
* DOES method
*/
struct xpvhv_aux *aux = HvAUX(stash);
aux->xhv_class_superclass = NULL;
aux->xhv_class_initfields_cv = NULL;
aux->xhv_class_adjust_blocks = NULL;
aux->xhv_class_fields = NULL;
aux->xhv_class_next_fieldix = 0;
aux->xhv_class_param_map = NULL;
aux->xhv_aux_flags |= HvAUXf_IS_CLASS;
SAVEDESTRUCTOR_X(invoke_class_seal, stash);
/* Prepare a suspended compcv for parsing field init expressions */
{
I32 floor_ix = start_subparse(FALSE, 0);
CvIsMETHOD_on(PL_compcv);
/* We don't want to make `$self` visible during the expression but we
* still need to give it a name. Make it unusable from pure perl
*/
PADOFFSET padix = pad_add_name_pvs("$(self)", 0, NULL, NULL);
assert(padix == PADIX_SELF);
padix = pad_add_name_pvs("%(params)", 0, NULL, NULL);
assert(padix == PADIX_PARAMS);
PERL_UNUSED_VAR(padix);
Newx(aux->xhv_class_suspended_initfields_compcv, 1, struct suspended_compcv);
suspend_compcv(aux->xhv_class_suspended_initfields_compcv);
LEAVE_SCOPE(floor_ix);
}
}
#define split_package_ver(value, pkgname, pkgversion) S_split_package_ver(aTHX_ value, pkgname, pkgversion)
static const char *S_split_package_ver(pTHX_ SV *value, SV *pkgname, SV *pkgversion)
{
const char *start = SvPVX(value),
*p = start,
*end = start + SvCUR(value);
while(*p && !isSPACE_utf8_safe(p, end))
p += UTF8SKIP(p);
sv_setpvn(pkgname, start, p - start);
if(SvUTF8(value))
SvUTF8_on(pkgname);
Size_t advance;
while(*p && (advance = isSPACE_utf8_safe(p, end)))
p += advance;
if(*p) {
/* scan_version() gets upset about trailing content. We need to extract
* exactly what it wants
*/
start = p;
if(*p == 'v')
p++;
while(*p && strchr("0123456789._", *p))
p++;
SV *tmpsv = newSVpvn(start, p - start);
SAVEFREESV(tmpsv);
scan_version(SvPVX(tmpsv), pkgversion, FALSE);
}
while(*p && (advance = isSPACE_utf8_safe(p, end)))
p += advance;
return p;
}
#define ensure_module_version(module, version) S_ensure_module_version(aTHX_ module, version)
static void S_ensure_module_version(pTHX_ SV *module, SV *version)
{
ENTER;
PUSHMARK(PL_stack_sp);
rpp_xpush_2(module, version);
call_method("VERSION", G_VOID);
LEAVE;
}
#define split_attr_nameval(sv, namp, valp) S_split_attr_nameval(aTHX_ sv, namp, valp)
static void S_split_attr_nameval(pTHX_ SV *sv, SV **namp, SV **valp)
{
STRLEN svlen = SvCUR(sv);
U32 do_utf8 = SvUTF8(sv) ? SVf_UTF8 : 0;
const char *paren_at = (const char *)memchr(SvPVX(sv), '(', svlen);
if(paren_at) {
STRLEN namelen = paren_at - SvPVX(sv);
if(SvPVX(sv)[svlen-1] != ')')
/* Should be impossible to reach this by parsing regular perl code
* by as class_apply_attributes() is XS-visible API it might still
* be reachable. As it's likely unreachable by normal perl code,
* don't bother listing it in perldiag.
*/
/* diag_listed_as: SKIPME */
croak("Malformed attribute string");
*namp = newSVpvn_flags(SvPVX(sv), namelen, SVs_TEMP|do_utf8);
const char *value_at = paren_at + 1;
const char *value_max = SvPVX(sv) + svlen - 2;
/* TODO: We're only obeying ASCII whitespace here */
/* Trim whitespace at the start */
while(value_at < value_max && isSPACE(*value_at))
value_at += 1;
while(value_max > value_at && isSPACE(*value_max))
value_max -= 1;
if(value_max >= value_at)
*valp = newSVpvn_flags(value_at, value_max - value_at + 1, SVs_TEMP|do_utf8);
else
*valp = NULL;
}
else {
*namp = sv;
*valp = NULL;
}
}
static void
apply_class_attribute_isa(pTHX_ HV *stash, SV *value)
{
assert(HvSTASH_IS_CLASS(stash));
struct xpvhv_aux *aux = HvAUX(stash);
/* Parse `value` into name + version */
SV *superclassname = sv_newmortal(), *superclassver = sv_newmortal();
const char *end = split_package_ver(value, superclassname, superclassver);
if(*end)
croak("Unexpected characters while parsing class :isa attribute: %s", end);
if(aux->xhv_class_superclass)
croak("Class already has a superclass, cannot add another");
HV *superstash = gv_stashsv(superclassname, 0);
if (!superstash || !HvSTASH_IS_CLASS(superstash)) {
/* Try to `require` the module then attempt a second time */
load_module(PERL_LOADMOD_NOIMPORT, newSVsv(superclassname), NULL, NULL);
superstash = gv_stashsv(superclassname, 0);
}
if(!superstash || !HvSTASH_IS_CLASS(superstash))
/* TODO: This would be a useful feature addition */
croak("Class :isa attribute requires a class but %" HvNAMEf_QUOTEDPREFIX " is not one",
HvNAMEfARG(superstash));
if(superclassver && SvOK(superclassver))
ensure_module_version(superclassname, superclassver);
/* TODO: Suuuurely there's a way to fetch this neatly with stash + "ISA"
* You'd think that GvAV() of hv_fetchs() would do it, but no, because it
* won't lazily create a proper (magical) GV if one didn't already exist.
*/
{
SV *isaname = newSVpvf("%" HEKf "::ISA", HvNAME_HEK(stash));
sv_2mortal(isaname);
AV *isa = get_av(SvPV_nolen(isaname), GV_ADD | (SvFLAGS(isaname) & SVf_UTF8));
ENTER;
/* Temporarily remove the SVf_READONLY flag */
SAVESETSVFLAGS((SV *)isa, SVf_READONLY|SVf_PROTECT, SVf_READONLY|SVf_PROTECT);
SvREADONLY_off((SV *)isa);
av_push(isa, newSVsv(value));
LEAVE;
}
aux->xhv_class_superclass = (HV *)SvREFCNT_inc(superstash);
struct xpvhv_aux *superaux = HvAUX(superstash);
aux->xhv_class_next_fieldix = superaux->xhv_class_next_fieldix;
if(superaux->xhv_class_adjust_blocks) {
if(!aux->xhv_class_adjust_blocks)
aux->xhv_class_adjust_blocks = newAV();
for(SSize_t i = 0; i <= AvFILL(superaux->xhv_class_adjust_blocks); i++)
av_push(aux->xhv_class_adjust_blocks, AvARRAY(superaux->xhv_class_adjust_blocks)[i]);
}
if(superaux->xhv_class_param_map) {
aux->xhv_class_param_map = newHVhv(superaux->xhv_class_param_map);
}
}
static struct {
const char *name;
bool requires_value;
void (*apply)(pTHX_ HV *stash, SV *value);
} const class_attributes[] = {
{ .name = "isa",
.requires_value = true,
.apply = &apply_class_attribute_isa,
},
{ NULL, false, NULL }
};
static void
S_class_apply_attribute(pTHX_ HV *stash, OP *attr)
{
assert(attr->op_type == OP_CONST);
SV *name, *value;
split_attr_nameval(cSVOPx_sv(attr), &name, &value);
for(int i = 0; class_attributes[i].name; i++) {
/* TODO: These attribute names are not UTF-8 aware */
if(!strEQ(SvPVX(name), class_attributes[i].name))
continue;
if(class_attributes[i].requires_value && !(value && SvOK(value)))
croak("Class attribute %" SVf " requires a value", SVfARG(name));
(*class_attributes[i].apply)(aTHX_ stash, value);
return;
}
croak("Unrecognized class attribute %" SVf, SVfARG(name));
}
void
Perl_class_apply_attributes(pTHX_ HV *stash, OP *attrlist)
{
PERL_ARGS_ASSERT_CLASS_APPLY_ATTRIBUTES;
if(!attrlist)
return;
if(attrlist->op_type == OP_NULL) {
op_free(attrlist);
return;
}
if(attrlist->op_type == OP_LIST) {
OP *o = cLISTOPx(attrlist)->op_first;
assert(o->op_type == OP_PUSHMARK);
o = OpSIBLING(o);
for(; o; o = OpSIBLING(o))
S_class_apply_attribute(aTHX_ stash, o);
}
else
S_class_apply_attribute(aTHX_ stash, attrlist);
op_free(attrlist);
}
/*
Called when a compilation failure occurs when defining a class.
Returns the given stash to a clean state, as if none of the class has
been defined so a new attempt can be made.
*/
static void
S_class_cleanup_definition(pTHX_ HV *stash) {
struct xpvhv_aux *aux = HvAUX(stash);
SvREFCNT_dec(aux->xhv_class_superclass);
aux->xhv_class_superclass = NULL;
/* clean up adjust blocks */
SvREFCNT_dec(aux->xhv_class_adjust_blocks);
aux->xhv_class_adjust_blocks = NULL;
/* name to slot index */
SvREFCNT_dec(aux->xhv_class_param_map);
aux->xhv_class_param_map = NULL;
/* clean up the ops for defaults for fields, if any, since
padname_free() doesn't.
*/
PADNAMELIST *fieldnames = aux->xhv_class_fields;
if (fieldnames) {
for(SSize_t i = PadnamelistMAX(fieldnames); i >= 0 ; i--) {
PADNAME *pn = PadnamelistARRAY(fieldnames)[i];
op_free(PadnameFIELDINFO(pn)->defop);
PadnameFIELDINFO(pn)->defop = NULL;
}
PadnamelistREFCNT_dec(fieldnames);
aux->xhv_class_fields = NULL;
}
/* clean up methods */
/* should we keep a separate list of these instead? */
if (hv_iterinit(stash)) {
HE *he;
while ((he = hv_iternext(stash)) != NULL) {
STRLEN klen;
const char * const kpv = HePV(he, klen);
SV *entry = HeVAL(he);
CV *cv = NULL;
if (SvTYPE(entry) == SVt_PVGV
&& (cv = GvCV((GV*)entry))
&& (CvIsMETHOD(cv) || memEQs(kpv, klen, "new"))) {
SvREFCNT_dec_NN(cv);
GvCV_set((GV*)entry, NULL);
}
else if (SvROK(entry)) {
SV *sv = SvRV(entry);
if (SvTYPE(sv) == SVt_PVCV
&& (CvIsMETHOD((CV*)sv) || memEQs(kpv, klen, "new"))) {
(void)hv_delete(stash, kpv, HeUTF8(he) ? -(I32)klen : (I32)klen,
G_DISCARD);
}
}
}
++PL_sub_generation;
}
/* field clean up */
resume_compcv_final(aux->xhv_class_suspended_initfields_compcv);
SvREFCNT_dec(PL_compcv);
Safefree(aux->xhv_class_suspended_initfields_compcv);
aux->xhv_class_suspended_initfields_compcv = NULL;
/* remove any ISA entries */
SV *isaname = sv_2mortal(newSVpvf("%" HEKf "::ISA", HvNAME_HEK(stash)));
AV *isa = get_av(SvPV_nolen(isaname), (SvFLAGS(isaname) & SVf_UTF8));
if (isa) {
/* we make this read-only above since class-keyword
classes manage ISA themselves, the class has failed to
load, so we no longer manage it.
*/
SvREADONLY_off((SV *)isa);
av_clear(isa);
}
/* no longer a class */
aux->xhv_aux_flags &= ~HvAUXf_IS_CLASS;
}
void
Perl_class_seal_stash(pTHX_ HV *stash)
{
PERL_ARGS_ASSERT_CLASS_SEAL_STASH;
assert(HvSTASH_IS_CLASS(stash));
if (PL_parser->error_count) {
/* we had errors, clean up */
class_cleanup_definition(stash);
return;
}
struct xpvhv_aux *aux = HvAUX(stash);
/* generate initfields CV */
I32 floor_ix = PL_savestack_ix;
SAVEI32(PL_subline);
save_item(PL_subname);
resume_compcv_final(aux->xhv_class_suspended_initfields_compcv);
/* Some OP_INITFIELD ops will need to populate the pad with their
* result because later ops will rely on it. There's no need to do
* this for every op though. Store a mapping to work out which ones
* we'll need.
*/
PADNAMELIST *pnl = PadlistNAMES(CvPADLIST(PL_compcv));
HV *fieldix_to_padix = newHV();
SAVEFREESV((SV *)fieldix_to_padix);
/* padix 0 == @_; padix 1 == $self. Start at 2 */
for(PADOFFSET padix = 2; padix <= PadnamelistMAX(pnl); padix++) {
PADNAME *pn = PadnamelistARRAY(pnl)[padix];
if(!pn || !PadnameIsFIELD(pn))
continue;
U32 fieldix = PadnameFIELDINFO(pn)->fieldix;
(void)hv_store_ent(fieldix_to_padix, sv_2mortal(newSVuv(fieldix)), newSVuv(padix), 0);
}
OP *ops = NULL;
ops = op_append_list(OP_LINESEQ, ops,
newUNOP_AUX(OP_METHSTART, OPpINITFIELDS << 8, NULL, NULL));
if(aux->xhv_class_superclass) {
HV *superstash = aux->xhv_class_superclass;
assert(HvSTASH_IS_CLASS(superstash));
struct xpvhv_aux *superaux = HvAUX(superstash);
/* Build an OP_ENTERSUB */
OP *o = newLISTOPn(OP_ENTERSUB, OPf_WANT_VOID|OPf_STACKED,
newPADxVOP(OP_PADSV, 0, PADIX_SELF),
newPADxVOP(OP_PADHV, OPf_REF, PADIX_PARAMS),
/* TODO: This won't work at all well under `use threads` because
* it embeds the CV * to the superclass initfields CV right into
* the optree. Maybe we'll have to pop it in the pad or something
*/
newSVOP(OP_CONST, 0, (SV *)superaux->xhv_class_initfields_cv),
NULL);
ops = op_append_list(OP_LINESEQ, ops, o);
}
PADNAMELIST *fieldnames = aux->xhv_class_fields;
for(SSize_t i = 0; fieldnames && i <= PadnamelistMAX(fieldnames); i++) {
PADNAME *pn = PadnamelistARRAY(fieldnames)[i];
char sigil = PadnamePV(pn)[0];
PADOFFSET fieldix = PadnameFIELDINFO(pn)->fieldix;
/* Extract the OP_{NEXT,DB}STATE op from the defop so we can
* splice it in
*/
OP *valop = PadnameFIELDINFO(pn)->defop;
if(valop && valop->op_type == OP_LINESEQ) {
OP *o = cLISTOPx(valop)->op_first;
cLISTOPx(valop)->op_first = NULL;
cLISTOPx(valop)->op_last = NULL;
/* have to clear the OPf_KIDS flag or op_free() will get upset */
valop->op_flags &= ~OPf_KIDS;
op_free(valop);
OP *fieldcop = o;
assert(fieldcop->op_type == OP_NEXTSTATE || fieldcop->op_type == OP_DBSTATE);
o = OpSIBLING(o);
OpLASTSIB_set(fieldcop, NULL);
valop = o;
OpLASTSIB_set(valop, NULL);
ops = op_append_list(OP_LINESEQ, ops, fieldcop);
}
SV *paramname = PadnameFIELDINFO(pn)->paramname;
U8 op_priv = 0;
switch(sigil) {
case '$':
if(paramname) {
if(!valop) {
SV *message =
newSVpvf("Required parameter '%" SVf "' is missing for "
"%" HvNAMEf_QUOTEDPREFIX " constructor",
SVfARG(paramname), HvNAMEfARG(stash));
valop = newLISTOPn(OP_DIE, 0,
newSVOP(OP_CONST, 0, message),
NULL);
}
OP *helemop =
newBINOP(OP_HELEM, 0,
newPADxVOP(OP_PADHV, OPf_REF, PADIX_PARAMS),
newSVOP(OP_CONST, 0, SvREFCNT_inc(paramname)));
if(PadnameFIELDINFO(pn)->def_if_undef) {
/* delete $params{$paramname} // DEFOP */
valop = newLOGOP(OP_DOR, 0,
newUNOP(OP_DELETE, 0, helemop), valop);
}
else if(PadnameFIELDINFO(pn)->def_if_false) {
/* delete $params{$paramname} || DEFOP */
valop = newLOGOP(OP_OR, 0,
newUNOP(OP_DELETE, 0, helemop), valop);
}
else {
/* exists $params{$paramname} ? delete $params{$paramname} : DEFOP */
/* more efficient with the new OP_HELEMEXISTSOR */
valop = newLOGOP(OP_HELEMEXISTSOR, OPpHELEMEXISTSOR_DELETE << 8,
helemop, valop);
}
valop = op_contextualize(valop, G_SCALAR);
}
break;
case '@':
op_priv = OPpINITFIELD_AV;
break;
case '%':
op_priv = OPpINITFIELD_HV;
break;
default:
NOT_REACHED;
}
UNOP_AUX_item *aux;
aux = (UNOP_AUX_item *)PerlMemShared_malloc(sizeof(UNOP_AUX_item) * 2);
aux[0].uv = fieldix;
OP *fieldop = newUNOP_AUX(OP_INITFIELD, valop ? OPf_STACKED : 0, valop, aux);
fieldop->op_private = op_priv;
HE *he;
if((he = hv_fetch_ent(fieldix_to_padix, sv_2mortal(newSVuv(fieldix)), 0, 0)) &&
SvOK(HeVAL(he))) {
fieldop->op_targ = SvUV(HeVAL(he));
}
ops = op_append_list(OP_LINESEQ, ops, fieldop);
}
/* initfields CV should not get class_wrap_method_body() called on its
* body. pretend it isn't a method for now */
CvIsMETHOD_off(PL_compcv);
CV *initfields = newATTRSUB(floor_ix, NULL, NULL, NULL, ops);
CvIsMETHOD_on(initfields);
aux->xhv_class_initfields_cv = initfields;
}
void
Perl_class_prepare_initfield_parse(pTHX)
{
PERL_ARGS_ASSERT_CLASS_PREPARE_INITFIELD_PARSE;
assert(HvSTASH_IS_CLASS(PL_curstash));
struct xpvhv_aux *aux = HvAUX(PL_curstash);
resume_compcv_and_save(aux->xhv_class_suspended_initfields_compcv);
CvOUTSIDE_SEQ(PL_compcv) = PL_cop_seqmax;
}
void
Perl_class_prepare_method_parse(pTHX_ CV *cv)
{
PERL_ARGS_ASSERT_CLASS_PREPARE_METHOD_PARSE;
assert(cv == PL_compcv);
assert(HvSTASH_IS_CLASS(PL_curstash));
/* We expect this to be at the start of sub parsing, so there won't be
* anything in the pad yet
*/
assert(PL_comppad_name_fill == 0);
PADOFFSET padix;
padix = pad_add_name_pvs("$self", 0, NULL, NULL);
assert(padix == PADIX_SELF);
PERL_UNUSED_VAR(padix);
intro_my();
CvNOWARN_AMBIGUOUS_on(cv);
CvIsMETHOD_on(cv);
}
#define find_op_methstart(o) S_find_op_methstart(aTHX_ o)
static OP *
S_find_op_methstart(pTHX_ OP *o)
{
if(o->op_type == OP_METHSTART)
return o;
if(!(o->op_flags & OPf_KIDS))
return NULL;
for(OP *kid = cUNOPo->op_first; kid; kid = OpSIBLING(kid)) {
OP *methstart = find_op_methstart(kid);
if(methstart)
return methstart;
}
return NULL;
}
OP *
Perl_class_wrap_method_body(pTHX_ OP *o)
{
PERL_ARGS_ASSERT_CLASS_WRAP_METHOD_BODY;
if(!o)
return o;
/* Walk the pad of this CV looking for lexicals with field info. These
* will be the fields used by this particular method, which we build into
* a list for the OP_METHSTART op. This ensures we only set up the fields
* needed by this particular method body, rather than every available
* field in the whole class
*/
PADNAMELIST *pnl = PadlistNAMES(CvPADLIST(PL_compcv));
AV *fieldmap = newAV();
UV max_fieldix = 0;
SAVEFREESV((SV *)fieldmap);
/* padix 0 == @_; padix 1 == $self. Start at 2 */
for(PADOFFSET padix = 2; padix <= PadnamelistMAX(pnl); padix++) {
PADNAME *pn = PadnamelistARRAY(pnl)[padix];
if(!pn || !PadnameIsFIELD(pn))
continue;
U32 fieldix = PadnameFIELDINFO(pn)->fieldix;
if(fieldix > max_fieldix)
max_fieldix = fieldix;
av_push_simple(fieldmap, newSVuv(padix));
av_push_simple(fieldmap, newSVuv(fieldix));
}
UNOP_AUX_item *aux = NULL;
if(av_count(fieldmap)) {
aux = (UNOP_AUX_item *)PerlMemShared_malloc(
sizeof(UNOP_AUX_item)
* (2 + av_count(fieldmap))
);
UNOP_AUX_item *ap = aux;
(ap++)->uv = av_count(fieldmap) / 2;
(ap++)->uv = max_fieldix;
for(Size_t i = 0; i < av_count(fieldmap); i++)
(ap++)->uv = SvUV(AvARRAY(fieldmap)[i]);
}
/* If this is an empty method body then o will be an OP_STUB and not a
* list. This will confuse op_sibling_splice() */
if(o->op_type != OP_LINESEQ)
o = newLISTOP(OP_LINESEQ, 0, o, NULL);
if(CvSIGNATURE(PL_compcv)) {
/* A signatured method has already injected the OP_METHSTART; we just
* have to find it and attach the aux structure to it
*/
OP *methstartop = find_op_methstart(o);
assert(methstartop);
assert(!cUNOP_AUXx(methstartop)->op_aux);
cUNOP_AUXx(methstartop)->op_aux = aux;
}
else
op_sibling_splice(o, NULL, 0, newUNOP_AUX(OP_METHSTART, 0, NULL, aux));
return o;
}
void
Perl_class_add_field(pTHX_ HV *stash, PADNAME *pn)
{
PERL_ARGS_ASSERT_CLASS_ADD_FIELD;
assert(HvSTASH_IS_CLASS(stash));
struct xpvhv_aux *aux = HvAUX(stash);
PADOFFSET fieldix = aux->xhv_class_next_fieldix;
aux->xhv_class_next_fieldix++;
Newxz(PadnameFIELDINFO(pn), 1, struct padname_fieldinfo);
PadnameFLAGS(pn) |= PADNAMEf_FIELD;
PadnameFIELDINFO(pn)->refcount = 1;
PadnameFIELDINFO(pn)->fieldix = fieldix;
PadnameFIELDINFO(pn)->fieldstash = (HV *)SvREFCNT_inc(stash);
if(!aux->xhv_class_fields)
aux->xhv_class_fields = newPADNAMELIST(0);
padnamelist_store(aux->xhv_class_fields, PadnamelistMAX(aux->xhv_class_fields)+1, pn);
PadnameREFCNT_inc(pn);
}
/* Adds a pad entry to PL_compcv to make the given field visible. This works
* even before the field has been properly `intro_my()`'ed and is thus usable
* during attributes declared on the same newly-field.
*/
#define pad_import_field(fieldpn) S_pad_import_field(aTHX_ fieldpn)
static PADOFFSET
S_pad_import_field(pTHX_ PADNAME *fieldpn)
{
assert(PadnameIsFIELD(fieldpn));
/* We can't just pad_findmy_pvn() because the actual field may not have been
* intro_my()'ed yet */
PADNAME *name = newPADNAMEouter(fieldpn);
PADOFFSET padix = pad_alloc(OP_PADSV, SVs_PADMY);
padnamelist_store(PL_comppad_name, padix, name);
return padix;
}
static void
apply_field_attribute_param(pTHX_ PADNAME *pn, SV *value)
{
if(!value)
/* Default to name minus the sigil */
value = newSVpvn_utf8(PadnamePV(pn) + 1, PadnameLEN(pn) - 1, PadnameUTF8(pn));
if(PadnamePV(pn)[0] != '$')
croak("Only scalar fields can take a :param attribute");
if(PadnameFIELDINFO(pn)->paramname)
croak("Field already has a parameter name, cannot add another");
HV *stash = PadnameFIELDINFO(pn)->fieldstash;
assert(HvSTASH_IS_CLASS(stash));
struct xpvhv_aux *aux = HvAUX(stash);
if(aux->xhv_class_param_map &&
hv_exists_ent(aux->xhv_class_param_map, value, 0))
croak("Cannot assign :param(%" SVf ") to field %" SVf " because that name is already in use",
SVfARG(value), SVfARG(PadnameSV(pn)));
PadnameFIELDINFO(pn)->paramname = SvREFCNT_inc(value);
if(!aux->xhv_class_param_map)
aux->xhv_class_param_map = newHV();
(void)hv_store_ent(aux->xhv_class_param_map, value, newSVuv(PadnameFIELDINFO(pn)->fieldix), 0);
}
static void
apply_field_attribute_reader(pTHX_ PADNAME *pn, SV *value)
{
if(value)
SvREFCNT_inc(value);
else
/* Default to name minus the sigil */
value = newSVpvn_utf8(PadnamePV(pn) + 1, PadnameLEN(pn) - 1, PadnameUTF8(pn));
if(!valid_identifier_sv(value))
croak("%" SVf_QUOTEDPREFIX " is not a valid name for a generated method", value);
I32 floor_ix = start_subparse(FALSE, 0);
SAVEFREESV(PL_compcv);
CvIsMETHOD_on(PL_compcv);
I32 save_ix = block_start(TRUE);
PADOFFSET padix;
padix = pad_add_name_pvs("$self", 0, NULL, NULL);
assert(padix == PADIX_SELF);
subsignature_start();
CvSIGNATURE_on(PL_compcv);
OP *sigop = subsignature_finish();
padix = pad_import_field(pn);
intro_my();
OP *retop;
{
OPCODE optype = 0;
switch(PadnamePV(pn)[0]) {
case '$': optype = OP_PADSV; break;
case '@': optype = OP_PADAV; break;
case '%': optype = OP_PADHV; break;
default: NOT_REACHED;
}
retop = newLISTOP(OP_RETURN, 0,
newOP(OP_PUSHMARK, 0),
newPADxVOP(optype, 0, padix));
}
OP *ops = newLISTOPn(OP_LINESEQ, 0,
sigop,
retop,
NULL);
SvREFCNT_inc(PL_compcv);
ops = block_end(save_ix, ops);
OP *nameop = newSVOP(OP_CONST, 0, value);
CV *cv = newATTRSUB(floor_ix, nameop, NULL, NULL, ops);
if (cv)
CvIsMETHOD_on(cv);
}
static void
apply_field_attribute_writer(pTHX_ PADNAME *pn, SV *value)
{
char sigil = PadnamePV(pn)[0];
if(sigil != '$')
croak("Cannot apply a :writer attribute to a non-scalar field");
if(value)
SvREFCNT_inc(value);
else {
/* Default to "set_" . name minus the sigil */
value = newSVpvs("set_");
sv_catpvn_flags(value, PadnamePV(pn) + 1, PadnameLEN(pn) - 1,
PadnameUTF8(pn) ? SV_CATUTF8 : 0);
}
if(!valid_identifier_sv(value))
croak("%" SVf_QUOTEDPREFIX " is not a valid name for a generated method", value);
I32 floor_ix = start_subparse(FALSE, 0);
SAVEFREESV(PL_compcv);
CvIsMETHOD_on(PL_compcv);
I32 save_ix = block_start(TRUE);
PADOFFSET padix;
padix = pad_add_name_pvs("$self", 0, NULL, NULL);
assert(padix == PADIX_SELF);
subsignature_start();
CvSIGNATURE_on(PL_compcv);
/* param pad variable doesn't technically need a name, so don't bother as
* reusing the field name will provoke a warning */
PADOFFSET param_padix = padix = pad_add_name_pvn("$", 1, 0, NULL, NULL);
intro_my();
subsignature_append_positional(param_padix, 0, NULL);
OP *sigop = subsignature_finish();
padix = pad_import_field(pn);
intro_my();
OP *assignop = newBINOP(OP_SASSIGN, 0,
newPADxVOP(OP_PADSV, 0, param_padix),
newPADxVOP(OP_PADSV, OPf_MOD|OPf_REF, padix));
OP *retop = newLISTOP(OP_RETURN, 0,
newOP(OP_PUSHMARK, 0),
newPADxVOP(OP_PADSV, 0, PADIX_SELF));
OP *ops = newLISTOPn(OP_LINESEQ, 0,
sigop,
assignop,
retop,
NULL);
SvREFCNT_inc(PL_compcv);
ops = block_end(save_ix, ops);
OP *nameop = newSVOP(OP_CONST, 0, value);
CV *cv = newATTRSUB(floor_ix, nameop, NULL, NULL, ops);
if (cv)
CvIsMETHOD_on(cv);
}
static struct {
const char *name;
bool requires_value;
void (*apply)(pTHX_ PADNAME *pn, SV *value);
} const field_attributes[] = {
{ .name = "param",
.requires_value = false,
.apply = &apply_field_attribute_param,
},
{ .name = "reader",
.requires_value = false,
.apply = &apply_field_attribute_reader,
},
{ .name = "writer",
.requires_value = false,
.apply = &apply_field_attribute_writer,
},
{ NULL, false, NULL }
};
static void
S_class_apply_field_attribute(pTHX_ PADNAME *pn, OP *attr)
{
assert(attr->op_type == OP_CONST);
SV *name, *value;
split_attr_nameval(cSVOPx_sv(attr), &name, &value);
for(int i = 0; field_attributes[i].name; i++) {
/* TODO: These attribute names are not UTF-8 aware */
if(!strEQ(SvPVX(name), field_attributes[i].name))
continue;
if(field_attributes[i].requires_value && !(value && SvOK(value)))
croak("Field attribute %" SVf " requires a value", SVfARG(name));
(*field_attributes[i].apply)(aTHX_ pn, value);
return;
}
croak("Unrecognized field attribute %" SVf, SVfARG(name));
}
void
Perl_class_apply_field_attributes(pTHX_ PADNAME *pn, OP *attrlist)
{
PERL_ARGS_ASSERT_CLASS_APPLY_FIELD_ATTRIBUTES;
if(!attrlist)
return;
if(attrlist->op_type == OP_NULL) {
op_free(attrlist);
return;
}
if(attrlist->op_type == OP_LIST) {
OP *o = cLISTOPx(attrlist)->op_first;
assert(o->op_type == OP_PUSHMARK);
o = OpSIBLING(o);
for(; o; o = OpSIBLING(o))
S_class_apply_field_attribute(aTHX_ pn, o);
}
else
S_class_apply_field_attribute(aTHX_ pn, attrlist);
op_free(attrlist);
}
void
Perl_class_set_field_defop(pTHX_ PADNAME *pn, OPCODE defmode, OP *defop)
{
PERL_ARGS_ASSERT_CLASS_SET_FIELD_DEFOP;
assert(defmode == 0 || defmode == OP_ORASSIGN || defmode == OP_DORASSIGN);
assert(HvSTASH_IS_CLASS(PL_curstash));
op_free(PadnameFIELDINFO(pn)->defop);
/* set here to ensure clean up if forbid_outofblock_ops() throws */
PadnameFIELDINFO(pn)->defop = defop;
forbid_outofblock_ops(defop, "field initialiser expression");
char sigil = PadnamePV(pn)[0];
switch(sigil) {
case '$':
defop = op_contextualize(defop, G_SCALAR);
break;
case '@':
case '%':
defop = op_contextualize(op_force_list(defop), G_LIST);
break;
}
PadnameFIELDINFO(pn)->defop = newLISTOP(OP_LINESEQ, 0,
newSTATEOP(0, NULL, NULL), defop);
switch(defmode) {
case OP_DORASSIGN:
PadnameFIELDINFO(pn)->def_if_undef = true;
break;
case OP_ORASSIGN:
PadnameFIELDINFO(pn)->def_if_false = true;
break;
}
}
void
Perl_class_add_ADJUST(pTHX_ HV *stash, CV *cv)
{
PERL_ARGS_ASSERT_CLASS_ADD_ADJUST;
assert(HvSTASH_IS_CLASS(stash));
struct xpvhv_aux *aux = HvAUX(stash);
if(!aux->xhv_class_adjust_blocks)
aux->xhv_class_adjust_blocks = newAV();
av_push(aux->xhv_class_adjust_blocks, (SV *)cv);
}
OP *
Perl_ck_classname(pTHX_ OP *o)
{
if(!CvIsMETHOD(PL_compcv))
croak("Cannot use __CLASS__ outside of a method or field initializer expression");
return o;
}
PP(pp_classname)
{
dTARGET;
SV *self = PAD_SVl(PADIX_SELF);
assert(SvTYPE(SvRV(self)) == SVt_PVOBJ);
rpp_xpush_1(TARG);
sv_ref(TARG, SvRV(self), true);
return NORMAL;
}
/*
* ex: set ts=8 sts=4 sw=4 et:
*/
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