NAME¶
perlintern - autogenerated documentation of purely internal Perl functions
DESCRIPTION¶
This file is the autogenerated documentation of functions in the Perl
interpreter that are documented using Perl's internal documentation format but
are not marked as part of the Perl API. In other words,
they are not for
use in extensions!
Compile-time scope hooks¶
- BhkENTRY
- Return an entry from the BHK structure. which is a
preprocessor token indicating which entry to return. If the appropriate
flag is not set this will return NULL. The type of the return value
depends on which entry you ask for.
NOTE: this function is experimental and may change or be removed without
notice.
void * BhkENTRY(BHK *hk, which)
- BhkFLAGS
- Return the BHK's flags.
NOTE: this function is experimental and may change or be removed without
notice.
U32 BhkFLAGS(BHK *hk)
- CALL_BLOCK_HOOKS
- Call all the registered block hooks for type which.
which is a preprocessing token; the type of arg depends on
which.
NOTE: this function is experimental and may change or be removed without
notice.
void CALL_BLOCK_HOOKS(which, arg)
CV reference counts and CvOUTSIDE¶
- CvWEAKOUTSIDE
- Each CV has a pointer, "CvOUTSIDE()", to its
lexically enclosing CV (if any). Because pointers to anonymous sub
prototypes are stored in "&" pad slots, it is a possible to
get a circular reference, with the parent pointing to the child and
vice-versa. To avoid the ensuing memory leak, we do not increment the
reference count of the CV pointed to by "CvOUTSIDE" in the
one specific instance that the parent has a "&" pad
slot pointing back to us. In this case, we set the
"CvWEAKOUTSIDE" flag in the child. This allows us to determine
under what circumstances we should decrement the refcount of the parent
when freeing the child.
There is a further complication with non-closure anonymous subs (i.e. those
that do not refer to any lexicals outside that sub). In this case, the
anonymous prototype is shared rather than being cloned. This has the
consequence that the parent may be freed while there are still active
children, eg
BEGIN { $a = sub { eval '$x' } }
In this case, the BEGIN is freed immediately after execution since there are
no active references to it: the anon sub prototype has
"CvWEAKOUTSIDE" set since it's not a closure, and $a points to
the same CV, so it doesn't contribute to BEGIN's refcount either. When $a
is executed, the "eval '$x'" causes the chain of
"CvOUTSIDE"s to be followed, and the freed BEGIN is accessed.
To avoid this, whenever a CV and its associated pad is freed, any
"&" entries in the pad are explicitly removed from the pad,
and if the refcount of the pointed-to anon sub is still positive, then
that child's "CvOUTSIDE" is set to point to its grandparent.
This will only occur in the single specific case of a non-closure anon
prototype having one or more active references (such as $a above).
One other thing to consider is that a CV may be merely undefined rather than
freed, eg "undef &foo". In this case, its refcount may not
have reached zero, but we still delete its pad and its "CvROOT"
etc. Since various children may still have their "CvOUTSIDE"
pointing at this undefined CV, we keep its own "CvOUTSIDE" for
the time being, so that the chain of lexical scopes is unbroken. For
example, the following should print 123:
my $x = 123;
sub tmp { sub { eval '$x' } }
my $a = tmp();
undef &tmp;
print $a->();
bool CvWEAKOUTSIDE(CV *cv)
Embedding Functions¶
- cv_clone
- Clone a CV: make a new CV which points to the same code
etc, but which has a newly-created pad built by copying the prototype pad
and capturing any outer lexicals.
CV* cv_clone(CV* proto)
- cv_dump
- dump the contents of a CV
void cv_dump(const CV *cv, const char *title)
- do_dump_pad
- Dump the contents of a padlist
void do_dump_pad(I32 level, PerlIO *file, PADLIST *padlist, int full)
- intro_my
- "Introduce" my variables to visible status.
U32 intro_my()
- pad_add_anon
- Add an anon code entry to the current compiling pad
PADOFFSET pad_add_anon(SV* sv, OPCODE op_type)
- pad_add_name
- Create a new name and associated PADMY SV in the current
pad; return the offset. If "typestash" is valid, the name is for
a typed lexical; set the name's stash to that value. If
"ourstash" is valid, it's an our lexical, set the name's
SvOURSTASH to that value
If fake, it means we're cloning an existing entry
NOTE: this function is experimental and may change or be removed without
notice.
PADOFFSET pad_add_name(const char *name, const STRLEN len, const U32 flags, HV *typestash, HV *ourstash)
- pad_alloc
- Allocate a new my or tmp pad entry. For a my, simply push a
null SV onto the end of PL_comppad, but for a tmp, scan the pad from
PL_padix upwards for a slot which has no name and no active value.
PADOFFSET pad_alloc(I32 optype, U32 tmptype)
- pad_block_start
- Update the pad compilation state variables on entry to a
new block
void pad_block_start(int full)
- pad_check_dup
- Check for duplicate declarations: report any of:
* a my in the current scope with the same name;
* an our (anywhere in the pad) with the same name and the same stash
as "ourstash" "is_our" indicates that the name to check
is an 'our' declaration
void pad_check_dup(SV *name, const U32 flags, const HV *ourstash)
- pad_findlex
- Find a named lexical anywhere in a chain of nested pads.
Add fake entries in the inner pads if it's found in an outer one.
Returns the offset in the bottom pad of the lex or the fake lex. cv is the
CV in which to start the search, and seq is the current cop_seq to match
against. If warn is true, print appropriate warnings. The out_* vars
return values, and so are pointers to where the returned values should be
stored. out_capture, if non-null, requests that the innermost instance of
the lexical is captured; out_name_sv is set to the innermost matched
namesv or fake namesv; out_flags returns the flags normally associated
with the IVX field of a fake namesv.
Note that pad_findlex() is recursive; it recurses up the chain of
CVs, then comes back down, adding fake entries as it goes. It has to be
this way because fake namesvs in anon protoypes have to store in xlow the
index into the parent pad.
PADOFFSET pad_findlex(const char *name, const CV* cv, U32 seq, int warn, SV** out_capture, SV** out_name_sv, int *out_flags)
- pad_fixup_inner_anons
- For any anon CVs in the pad, change CvOUTSIDE of that CV
from old_cv to new_cv if necessary. Needed when a newly-compiled CV has to
be moved to a pre-existing CV struct.
void pad_fixup_inner_anons(PADLIST *padlist, CV *old_cv, CV *new_cv)
- pad_free
- Free the SV at offset po in the current pad.
void pad_free(PADOFFSET po)
- pad_leavemy
- Cleanup at end of scope during compilation: set the max seq
number for lexicals in this scope and warn of any lexicals that never got
introduced.
void pad_leavemy()
- pad_push
- Push a new pad frame onto the padlist, unless there's
already a pad at this depth, in which case don't bother creating a new
one. Then give the new pad an @_ in slot zero.
void pad_push(PADLIST *padlist, int depth)
- pad_reset
- Mark all the current temporaries for reuse
void pad_reset()
- pad_setsv
- Set the entry at offset po in the current pad to sv. Use
the macro PAD_SETSV() rather than calling this function directly.
void pad_setsv(PADOFFSET po, SV* sv)
- pad_swipe
- Abandon the tmp in the current pad at offset po and replace
with a new one.
void pad_swipe(PADOFFSET po, bool refadjust)
- pad_tidy
- Tidy up a pad after we've finished compiling it:
* remove most stuff from the pads of anonsub prototypes;
* give it a @_;
* mark tmps as such.
void pad_tidy(padtidy_type type)
Functions in file pad.h¶
- CX_CURPAD_SAVE
- Save the current pad in the given context block structure.
void CX_CURPAD_SAVE(struct context)
- CX_CURPAD_SV
- Access the SV at offset po in the saved current pad in the
given context block structure (can be used as an lvalue).
SV * CX_CURPAD_SV(struct context, PADOFFSET po)
- PAD_BASE_SV
- Get the value from slot "po" in the base
(DEPTH=1) pad of a padlist
SV * PAD_BASE_SV(PADLIST padlist, PADOFFSET po)
- PAD_CLONE_VARS
- Clone the state variables associated with running and
compiling pads.
void PAD_CLONE_VARS(PerlInterpreter *proto_perl, CLONE_PARAMS* param)
- PAD_COMPNAME_FLAGS
- Return the flags for the current compiling pad name at
offset "po". Assumes a valid slot entry.
U32 PAD_COMPNAME_FLAGS(PADOFFSET po)
- PAD_COMPNAME_GEN
- The generation number of the name at offset "po"
in the current compiling pad (lvalue). Note that "SvUVX" is
hijacked for this purpose.
STRLEN PAD_COMPNAME_GEN(PADOFFSET po)
- PAD_COMPNAME_GEN_set
- Sets the generation number of the name at offset
"po" in the current ling pad (lvalue) to "gen". Note
that "SvUV_set" is hijacked for this purpose.
STRLEN PAD_COMPNAME_GEN_set(PADOFFSET po, int gen)
- PAD_COMPNAME_OURSTASH
- Return the stash associated with an "our"
variable. Assumes the slot entry is a valid "our" lexical.
HV * PAD_COMPNAME_OURSTASH(PADOFFSET po)
- PAD_COMPNAME_PV
- Return the name of the current compiling pad name at offset
"po". Assumes a valid slot entry.
char * PAD_COMPNAME_PV(PADOFFSET po)
- PAD_COMPNAME_TYPE
- Return the type (stash) of the current compiling pad name
at offset "po". Must be a valid name. Returns null if not typed.
HV * PAD_COMPNAME_TYPE(PADOFFSET po)
- PAD_DUP
- Clone a padlist.
void PAD_DUP(PADLIST dstpad, PADLIST srcpad, CLONE_PARAMS* param)
- PAD_RESTORE_LOCAL
- Restore the old pad saved into the local variable opad by
PAD_SAVE_LOCAL()
void PAD_RESTORE_LOCAL(PAD *opad)
- PAD_SAVE_LOCAL
- Save the current pad to the local variable opad, then make
the current pad equal to npad
void PAD_SAVE_LOCAL(PAD *opad, PAD *npad)
- PAD_SAVE_SETNULLPAD
- Save the current pad then set it to null.
void PAD_SAVE_SETNULLPAD()
- PAD_SETSV
- Set the slot at offset "po" in the current pad to
"sv"
SV * PAD_SETSV(PADOFFSET po, SV* sv)
- PAD_SET_CUR
- Set the current pad to be pad "n" in the padlist,
saving the previous current pad. NB currently this macro expands to a
string too long for some compilers, so it's best to replace it with
SAVECOMPPAD();
PAD_SET_CUR_NOSAVE(padlist,n);
void PAD_SET_CUR(PADLIST padlist, I32 n)
- PAD_SET_CUR_NOSAVE
- like PAD_SET_CUR, but without the save
void PAD_SET_CUR_NOSAVE(PADLIST padlist, I32 n)
- PAD_SV
- Get the value at offset "po" in the current pad
void PAD_SV(PADOFFSET po)
- PAD_SVl
- Lightweight and lvalue version of "PAD_SV". Get
or set the value at offset "po" in the current pad. Unlike
"PAD_SV", does not print diagnostics with -DX. For internal use
only.
SV * PAD_SVl(PADOFFSET po)
- SAVECLEARSV
- Clear the pointed to pad value on scope exit. (i.e. the
runtime action of 'my')
void SAVECLEARSV(SV **svp)
- SAVECOMPPAD
- save PL_comppad and PL_curpad
void SAVECOMPPAD()
- SAVEPADSV
- Save a pad slot (used to restore after an iteration)
XXX DAPM it would make more sense to make the arg a PADOFFSET
void SAVEPADSV(PADOFFSET po)
Functions in file pp_ctl.c¶
- docatch
- Check for the cases 0 or 3 of cur_env.je_ret, only used
inside an eval context.
0 is used as continue inside eval,
3 is used for a die caught by an inner eval - continue inner loop
See cop.h: je_mustcatch, when set at any runlevel to TRUE, means eval ops
must establish a local jmpenv to handle exception traps.
OP* docatch(OP *o)
GV Functions¶
- gv_try_downgrade
- If the typeglob "gv" can be expressed more
succinctly, by having something other than a real GV in its place in the
stash, replace it with the optimised form. Basic requirements for this are
that "gv" is a real typeglob, is sufficiently ordinary, and is
only referenced from its package. This function is meant to be used when a
GV has been looked up in part to see what was there, causing upgrading,
but based on what was found it turns out that the real GV isn't required
after all.
If "gv" is a completely empty typeglob, it is deleted from the
stash.
If "gv" is a typeglob containing only a sufficiently-ordinary
constant sub, the typeglob is replaced with a scalar-reference placeholder
that more compactly represents the same thing.
NOTE: this function is experimental and may change or be removed without
notice.
void gv_try_downgrade(GV* gv)
- is_gv_magical_sv
- Returns "TRUE" if given the name of a magical GV.
Currently only useful internally when determining if a GV should be created
even in rvalue contexts.
"flags" is not used at present but available for future extension
to allow selecting particular classes of magical variable.
Currently assumes that "name" is NUL terminated (as well as len
being valid). This assumption is met by all callers within the perl core,
which all pass pointers returned by SvPV.
bool is_gv_magical_sv(SV *const name_sv, U32 flags)
Hash Manipulation Functions¶
- hv_ename_add
- Adds a name to a stash's internal list of effective names.
See "hv_ename_delete".
This is called when a stash is assigned to a new location in the symbol
table.
void hv_ename_add(HV *hv, const char *name, U32 len, U32 flags)
- hv_ename_delete
- Removes a name from a stash's internal list of effective
names. If this is the name returned by "HvENAME", then another
name in the list will take its place ("HvENAME" will use it).
This is called when a stash is deleted from the symbol table.
void hv_ename_delete(HV *hv, const char *name, U32 len, U32 flags)
- refcounted_he_chain_2hv
- Generates and returns a "HV *" representing the
content of a "refcounted_he" chain. flags is currently
unused and must be zero.
HV * refcounted_he_chain_2hv(const struct refcounted_he *c, U32 flags)
- refcounted_he_fetch_pv
- Like "refcounted_he_fetch_pvn", but takes a
nul-terminated string instead of a string/length pair.
SV * refcounted_he_fetch_pv(const struct refcounted_he *chain, const char *key, U32 hash, U32 flags)
- refcounted_he_fetch_pvn
- Search along a "refcounted_he" chain for an entry
with the key specified by keypv and keylen. If flags
has the "REFCOUNTED_HE_KEY_UTF8" bit set, the key octets are
interpreted as UTF-8, otherwise they are interpreted as Latin-1.
hash is a precomputed hash of the key string, or zero if it has not
been precomputed. Returns a mortal scalar representing the value
associated with the key, or &PL_sv_placeholder if there is no value
associated with the key.
SV * refcounted_he_fetch_pvn(const struct refcounted_he *chain, const char *keypv, STRLEN keylen, U32 hash, U32 flags)
- refcounted_he_fetch_pvs
- Like "refcounted_he_fetch_pvn", but takes a
literal string instead of a string/length pair, and no precomputed hash.
SV * refcounted_he_fetch_pvs(const struct refcounted_he *chain, const char *key, U32 flags)
- refcounted_he_fetch_sv
- Like "refcounted_he_fetch_pvn", but takes a Perl
scalar instead of a string/length pair.
SV * refcounted_he_fetch_sv(const struct refcounted_he *chain, SV *key, U32 hash, U32 flags)
- refcounted_he_free
- Decrements the reference count of a
"refcounted_he" by one. If the reference count reaches zero the
structure's memory is freed, which (recursively) causes a reduction of its
parent "refcounted_he"'s reference count. It is safe to pass a
null pointer to this function: no action occurs in this case.
void refcounted_he_free(struct refcounted_he *he)
- refcounted_he_inc
- Increment the reference count of a
"refcounted_he". The pointer to the "refcounted_he" is
also returned. It is safe to pass a null pointer to this function: no
action occurs and a null pointer is returned.
struct refcounted_he * refcounted_he_inc(struct refcounted_he *he)
- refcounted_he_new_pv
- Like "refcounted_he_new_pvn", but takes a
nul-terminated string instead of a string/length pair.
struct refcounted_he * refcounted_he_new_pv(struct refcounted_he *parent, const char *key, U32 hash, SV *value, U32 flags)
- refcounted_he_new_pvn
- Creates a new "refcounted_he". This consists of a
single key/value pair and a reference to an existing
"refcounted_he" chain (which may be empty), and thus forms a
longer chain. When using the longer chain, the new key/value pair takes
precedence over any entry for the same key further along the chain.
The new key is specified by keypv and keylen. If flags
has the "REFCOUNTED_HE_KEY_UTF8" bit set, the key octets are
interpreted as UTF-8, otherwise they are interpreted as Latin-1.
hash is a precomputed hash of the key string, or zero if it has not
been precomputed.
value is the scalar value to store for this key. value is
copied by this function, which thus does not take ownership of any
reference to it, and later changes to the scalar will not be reflected in
the value visible in the "refcounted_he". Complex types of
scalar will not be stored with referential integrity, but will be coerced
to strings. value may be either null or &PL_sv_placeholder to
indicate that no value is to be associated with the key; this, as with any
non-null value, takes precedence over the existence of a value for the key
further along the chain.
parent points to the rest of the "refcounted_he" chain to
be attached to the new "refcounted_he". This function takes
ownership of one reference to parent, and returns one reference to
the new "refcounted_he".
struct refcounted_he * refcounted_he_new_pvn(struct refcounted_he *parent, const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
- refcounted_he_new_pvs
- Like "refcounted_he_new_pvn", but takes a literal
string instead of a string/length pair, and no precomputed hash.
struct refcounted_he * refcounted_he_new_pvs(struct refcounted_he *parent, const char *key, SV *value, U32 flags)
- refcounted_he_new_sv
- Like "refcounted_he_new_pvn", but takes a Perl
scalar instead of a string/length pair.
struct refcounted_he * refcounted_he_new_sv(struct refcounted_he *parent, SV *key, U32 hash, SV *value, U32 flags)
IO Functions¶
- start_glob
- Function called by "do_readline" to spawn a glob
(or do the glob inside perl on VMS). This code used to be inline, but now
perl uses "File::Glob" this glob starter is only used by
miniperl during the build process. Moving it away shrinks pp_hot.c;
shrinking pp_hot.c helps speed perl up.
NOTE: this function is experimental and may change or be removed without
notice.
PerlIO* start_glob(SV *tmpglob, IO *io)
Magical Functions¶
- magic_clearhint
- Triggered by a delete from %^H, records the key to
"PL_compiling.cop_hints_hash".
int magic_clearhint(SV* sv, MAGIC* mg)
- magic_clearhints
- Triggered by clearing %^H, resets
"PL_compiling.cop_hints_hash".
int magic_clearhints(SV* sv, MAGIC* mg)
- magic_methcall
- Invoke a magic method (like FETCH).
* sv and mg are the tied thingy and the tie magic; * meth is the name of the
method to call; * argc is the number of args (in addition to $self) to
pass to the method;
the args themselves are any values following the argc argument. * flags:
G_DISCARD: invoke method with G_DISCARD flag and don't return a value
G_UNDEF_FILL: fill the stack with argc pointers to PL_sv_undef.
Returns the SV (if any) returned by the method, or NULL on failure.
SV* magic_methcall(SV *sv, const MAGIC *mg, const char *meth, U32 flags, U32 argc, ...)
- magic_sethint
- Triggered by a store to %^H, records the key/value pair to
"PL_compiling.cop_hints_hash". It is assumed that hints aren't
storing anything that would need a deep copy. Maybe we should warn if we
find a reference.
int magic_sethint(SV* sv, MAGIC* mg)
- mg_localize
- Copy some of the magic from an existing SV to new localized
version of that SV. Container magic (eg %ENV, $1, tie) gets copied, value
magic doesn't (eg taint, pos).
If setmagic is false then no set magic will be called on the new (empty) SV.
This typically means that assignment will soon follow (e.g. 'local $x =
$y'), and that will handle the magic.
void mg_localize(SV* sv, SV* nsv, bool setmagic)
MRO Functions¶
- mro_get_linear_isa_dfs
- Returns the Depth-First Search linearization of @ISA the
given stash. The return value is a read-only AV*. "level" should
be 0 (it is used internally in this function's recursion).
You are responsible for "SvREFCNT_inc()" on the return value if
you plan to store it anywhere semi-permanently (otherwise it might be
deleted out from under you the next time the cache is invalidated).
AV* mro_get_linear_isa_dfs(HV* stash, U32 level)
- mro_isa_changed_in
- Takes the necessary steps (cache invalidations, mostly)
when the @ISA of the given package has changed. Invoked by the
"setisa" magic, should not need to invoke directly.
void mro_isa_changed_in(HV* stash)
- mro_package_moved
- Call this function to signal to a stash that it has been
assigned to another spot in the stash hierarchy. "stash" is the
stash that has been assigned. "oldstash" is the stash it
replaces, if any. "gv" is the glob that is actually being
assigned to.
This can also be called with a null first argument to indicate that
"oldstash" has been deleted.
This function invalidates isa caches on the old stash, on all subpackages
nested inside it, and on the subclasses of all those, including
non-existent packages that have corresponding entries in
"stash".
It also sets the effective names ("HvENAME") on all the stashes as
appropriate.
If the "gv" is present and is not in the symbol table, then this
function simply returns. This checked will be skipped if "flags &
1".
void mro_package_moved(HV * const stash, HV * const oldstash, const GV * const gv, U32 flags)
Pad Data Structures¶
- CvPADLIST
- CV's can have CvPADLIST(cv) set to point to an AV.
For these purposes "forms" are a kind-of CV, eval""s are
too (except they're not callable at will and are always thrown away after
the eval"" is done executing). Require'd files are simply evals
without any outer lexical scope.
XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad, but
that is really the callers pad (a slot of which is allocated by every
entersub).
The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items
is managed "manual" (mostly in pad.c) rather than normal av.c
rules. The items in the AV are not SVs as for a normal AV, but other AVs:
0'th Entry of the CvPADLIST is an AV which represents the "names"
or rather the "static type information" for lexicals.
The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at
that depth of recursion into the CV. The 0'th slot of a frame AV is an AV
which is @_. other entries are storage for variables and op targets.
During compilation: "PL_comppad_name" is set to the names AV.
"PL_comppad" is set to the frame AV for the frame CvDEPTH == 1.
"PL_curpad" is set to the body of the frame AV (i.e.
AvARRAY(PL_comppad)).
During execution, "PL_comppad" and "PL_curpad" refer to
the live frame of the currently executing sub.
Iterating over the names AV iterates over all possible pad items. Pad slots
that are SVs_PADTMP (targets/GVs/constants) end up having &PL_sv_undef
"names" (see pad_alloc()).
Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names. The rest
are op targets/GVs/constants which are statically allocated or resolved at
compile time. These don't have names by which they can be looked up from
Perl code at run time through eval"" like my/our variables can
be. Since they can't be looked up by "name" but only by their
index allocated at compile time (which is usually in PL_op->op_targ),
wasting a name SV for them doesn't make sense.
The SVs in the names AV have their PV being the name of the variable.
xlow+1..xhigh inclusive in the NV union is a range of cop_seq numbers for
which the name is valid (accessed through the macros COP_SEQ_RANGE_LOW and
_HIGH). During compilation, these fields may hold the special value
PERL_PADSEQ_INTRO to indicate various stages:
COP_SEQ_RANGE_LOW _HIGH
----------------- -----
PERL_PADSEQ_INTRO 0 variable not yet introduced: { my ($x
valid-seq# PERL_PADSEQ_INTRO variable in scope: { my ($x)
valid-seq# valid-seq# compilation of scope complete: { my ($x) }
For typed lexicals name SV is SVt_PVMG and SvSTASH points at the type. For
"our" lexicals, the type is also SVt_PVMG, with the SvOURSTASH
slot pointing at the stash of the associated global (so that duplicate
"our" declarations in the same package can be detected). SvUVX
is sometimes hijacked to store the generation number during compilation.
If SvFAKE is set on the name SV, then that slot in the frame AV is a
REFCNT'ed reference to a lexical from "outside". In this case,
the name SV does not use xlow and xhigh to store a cop_seq range, since it
is in scope throughout. Instead xhigh stores some flags containing info
about the real lexical (is it declared in an anon, and is it capable of
being instantiated multiple times?), and for fake ANONs, xlow contains the
index within the parent's pad where the lexical's value is stored, to make
cloning quicker.
If the 'name' is '&' the corresponding entry in frame AV is a CV
representing a possible closure. (SvFAKE and name of '&' is not a
meaningful combination currently but could become so if "my sub foo
{}" is implemented.)
Note that formats are treated as anon subs, and are cloned each time write
is called (if necessary).
The flag SVs_PADSTALE is cleared on lexicals each time the my() is
executed, and set on scope exit. This allows the 'Variable $x is not
available' warning to be generated in evals, such as
{ my $x = 1; sub f { eval '$x'} } f();
For state vars, SVs_PADSTALE is overloaded to mean 'not yet initialised'
AV * CvPADLIST(CV *cv)
- pad_new
- Create a new compiling padlist, saving and updating the
various global vars at the same time as creating the pad itself. The
following flags can be OR'ed together:
padnew_CLONE this pad is for a cloned CV
padnew_SAVE save old globals
padnew_SAVESUB also save extra stuff for start of sub
PADLIST* pad_new(int flags)
Per-Interpreter Variables¶
- PL_DBsingle
- When Perl is run in debugging mode, with the -d
switch, this SV is a boolean which indicates whether subs are being
single-stepped. Single-stepping is automatically turned on after every
step. This is the C variable which corresponds to Perl's $DB::single
variable. See "PL_DBsub".
SV * PL_DBsingle
- PL_DBsub
- When Perl is run in debugging mode, with the -d
switch, this GV contains the SV which holds the name of the sub being
debugged. This is the C variable which corresponds to Perl's $DB::sub
variable. See "PL_DBsingle".
GV * PL_DBsub
- PL_DBtrace
- Trace variable used when Perl is run in debugging mode,
with the -d switch. This is the C variable which corresponds to
Perl's $DB::trace variable. See "PL_DBsingle".
SV * PL_DBtrace
- PL_dowarn
- The C variable which corresponds to Perl's $^W warning
variable.
bool PL_dowarn
- PL_last_in_gv
- The GV which was last used for a filehandle input
operation. ("<FH>")
GV* PL_last_in_gv
- PL_ofsgv
- The glob containing the output field separator -
"*," in Perl space.
GV* PL_ofsgv
- PL_rs
- The input record separator - $/ in Perl space.
SV* PL_rs
Stack Manipulation Macros¶
- djSP
- Declare Just "SP". This is actually identical to
"dSP", and declares a local copy of perl's stack pointer,
available via the "SP" macro. See "SP". (Available for
backward source code compatibility with the old (Perl 5.005) thread
model.)
djSP;
- LVRET
- True if this op will be the return value of an lvalue
subroutine
SV Manipulation Functions¶
- sv_add_arena
- Given a chunk of memory, link it to the head of the list of
arenas, and split it into a list of free SVs.
void sv_add_arena(char *const ptr, const U32 size, const U32 flags)
- sv_clean_all
- Decrement the refcnt of each remaining SV, possibly
triggering a cleanup. This function may have to be called multiple times
to free SVs which are in complex self-referential hierarchies.
I32 sv_clean_all()
- sv_clean_objs
- Attempt to destroy all objects not yet freed
void sv_clean_objs()
- sv_free_arenas
- Deallocate the memory used by all arenas. Note that all the
individual SV heads and bodies within the arenas must already have been
freed.
void sv_free_arenas()
SV-Body Allocation¶
- sv_2num
- Return an SV with the numeric value of the source SV, doing
any necessary reference or overload conversion. You must use the
"SvNUM(sv)" macro to access this function.
NOTE: this function is experimental and may change or be removed without
notice.
SV* sv_2num(SV *const sv)
Unicode Support¶
- find_uninit_var
- Find the name of the undefined variable (if any) that
caused the operator o to issue a "Use of uninitialized value"
warning. If match is true, only return a name if it's value matches
uninit_sv. So roughly speaking, if a unary operator (such as OP_COS)
generates a warning, then following the direct child of the op may yield
an OP_PADSV or OP_GV that gives the name of the undefined variable. On the
other hand, with OP_ADD there are two branches to follow, so we only print
the variable name if we get an exact match.
The name is returned as a mortal SV.
Assumes that PL_op is the op that originally triggered the error, and that
PL_comppad/PL_curpad points to the currently executing pad.
NOTE: this function is experimental and may change or be removed without
notice.
SV* find_uninit_var(const OP *const obase, const SV *const uninit_sv, bool top)
- report_uninit
- Print appropriate "Use of uninitialized variable"
warning
void report_uninit(const SV *uninit_sv)
Undocumented functions¶
The following functions have been flagged as part of the public API, but are
currently undocumented. Use them at your own risk, as the interfaces are
subject to change.
If you use one of them, you may wish to consider creating and submitting
documentation for it. If your patch is accepted, this will indicate that the
interface is stable (unless it is explicitly marked otherwise).
- F0convert
- Slab_to_rw
- _append_range_to_invlist
- _new_invlist
- _swash_inversion_hash
- _swash_to_invlist
- add_alternate
- add_cp_to_invlist
- add_data
- add_range_to_invlist
- add_utf16_textfilter
- addmad
- allocmy
- amagic_cmp
- amagic_cmp_locale
- amagic_i_ncmp
- amagic_ncmp
- anonymise_cv_maybe
- ao
- append_madprops
- apply
- apply_attrs
- apply_attrs_my
- assert_uft8_cache_coherent
- av_reify
- bad_type
- bind_match
- block_end
- block_start
- boot_core_PerlIO
- boot_core_UNIVERSAL
- boot_core_mro
- bytes_to_uni
- cando
- check_type_and_open
- check_uni
- check_utf8_print
- checkcomma
- checkposixcc
- ckwarn_common
- cl_and
- cl_anything
- cl_init
- cl_is_anything
- cl_or
- clear_placeholders
- closest_cop
- convert
- cop_free
- cr_textfilter
- create_eval_scope
- curmad
- curse
- cv_ckproto_len
- cvgv_set
- cvstash_set
- deb_curcv
- deb_stack_all
- deb_stack_n
- debprof
- debug_start_match
- del_sv
- delete_eval_scope
- deprecate_commaless_var_list
- destroy_matcher
- die_unwind
- div128
- do_aexec
- do_aexec5
- do_chomp
- do_delete_local
- do_eof
- do_exec
- do_exec3
- do_execfree
- do_ipcctl
- do_ipcget
- do_msgrcv
- do_msgsnd
- do_oddball
- do_op_xmldump
- do_pmop_xmldump
- do_print
- do_readline
- do_seek
- do_semop
- do_shmio
- do_smartmatch
- do_sysseek
- do_tell
- do_trans
- do_trans_complex
- do_trans_complex_utf8
- do_trans_count
- do_trans_count_utf8
- do_trans_simple
- do_trans_simple_utf8
- do_vecget
- do_vecset
- do_vop
- doeval
- dofile
- dofindlabel
- doform
- dooneliner
- doopen_pm
- doparseform
- dopoptoeval
- dopoptogiven
- dopoptolabel
- dopoptoloop
- dopoptosub_at
- dopoptowhen
- dump_all_perl
- dump_exec_pos
- dump_packsubs_perl
- dump_sub_perl
- dump_sv_child
- dump_trie
- dump_trie_interim_list
- dump_trie_interim_table
- dumpuntil
- dup_attrlist
- emulate_cop_io
- exec_failed
- expect_number
- feature_is_enabled
- filter_gets
- find_and_forget_pmops
- find_array_subscript
- find_beginning
- find_byclass
- find_hash_subscript
- find_in_my_stash
- find_script
- first_symbol
- fold_constants
- forbid_setid
- force_ident
- force_list
- force_next
- force_strict_version
- force_version
- force_word
- forget_pmop
- free_tied_hv_pool
- gen_constant_list
- get_aux_mg
- get_db_sub
- get_debug_opts
- get_hash_seed
- get_no_modify
- get_num
- get_opargs
- get_re_arg
- getenv_len
- glob_2number
- glob_assign_glob
- glob_assign_ref
- grok_bslash_c
- grok_bslash_o
- group_end
- gv_ename
- gv_get_super_pkg
- gv_init_sv
- gv_magicalize_isa
- gv_magicalize_overload
- hfreeentries
- hsplit
- hv_auxinit
- hv_backreferences_p
- hv_delete_common
- hv_kill_backrefs
- hv_magic_check
- hv_notallowed
- hv_undef_flags
- incline
- incpush
- incpush_if_exists
- incpush_use_sep
- ingroup
- init_argv_symbols
- init_dbargs
- init_debugger
- init_ids
- init_interp
- init_main_stash
- init_perllib
- init_postdump_symbols
- init_predump_symbols
- intuit_method
- intuit_more
- invert
- invlist_array
- invlist_destroy
- invlist_extend
- invlist_intersection
- invlist_len
- invlist_max
- invlist_set_len
- invlist_set_max
- invlist_trim
- invlist_union
- invoke_exception_hook
- io_close
- is_an_int
- is_handle_constructor
- is_inplace_av
- is_list_assignment
- is_utf8_X_L
- is_utf8_X_LV
- is_utf8_X_LVT
- is_utf8_X_LV_LVT_V
- is_utf8_X_T
- is_utf8_X_V
- is_utf8_X_begin
- is_utf8_X_extend
- is_utf8_X_non_hangul
- is_utf8_X_prepend
- is_utf8_char_slow
- is_utf8_common
- isa_lookup
- jmaybe
- join_exact
- keyword
- keyword_plugin_standard
- list
- listkids
- localize
- looks_like_bool
- lop
- mad_free
- madlex
- madparse
- magic_clear_all_env
- magic_clearenv
- magic_clearisa
- magic_clearpack
- magic_clearsig
- magic_existspack
- magic_freearylen_p
- magic_freeovrld
- magic_get
- magic_getarylen
- magic_getdefelem
- magic_getnkeys
- magic_getpack
- magic_getpos
- magic_getsig
- magic_getsubstr
- magic_gettaint
- magic_getuvar
- magic_getvec
- magic_killbackrefs
- magic_len
- magic_methcall1
- magic_methpack
- magic_nextpack
- magic_regdata_cnt
- magic_regdatum_get
- magic_regdatum_set
- magic_scalarpack
- magic_set
- magic_set_all_env
- magic_setamagic
- magic_setarylen
- magic_setcollxfrm
- magic_setdbline
- magic_setdefelem
- magic_setenv
- magic_setisa
- magic_setmglob
- magic_setnkeys
- magic_setpack
- magic_setpos
- magic_setregexp
- magic_setsig
- magic_setsubstr
- magic_settaint
- magic_setutf8
- magic_setuvar
- magic_setvec
- magic_sizepack
- magic_wipepack
- make_matcher
- make_trie
- make_trie_failtable
- malloc_good_size
- malloced_size
- matcher_matches_sv
- measure_struct
- mem_collxfrm
- mem_log_common
- mess_alloc
- method_common
- missingterm
- mod
- mode_from_discipline
- modkids
- more_bodies
- more_sv
- mro_clean_isarev
- mro_gather_and_rename
- mro_meta_dup
- mro_meta_init
- mul128
- mulexp10
- munge_qwlist_to_paren_list
- my_attrs
- my_betoh16
- my_betoh32
- my_betoh64
- my_betohi
- my_betohl
- my_betohs
- my_clearenv
- my_exit_jump
- my_htobe16
- my_htobe32
- my_htobe64
- my_htobei
- my_htobel
- my_htobes
- my_htole16
- my_htole32
- my_htole64
- my_htolei
- my_htolel
- my_htoles
- my_kid
- my_letoh16
- my_letoh32
- my_letoh64
- my_letohi
- my_letohl
- my_letohs
- my_lstat_flags
- my_stat_flags
- my_swabn
- my_unexec
- need_utf8
- newDEFSVOP
- newGIVWHENOP
- newGP
- newMADPROP
- newMADsv
- newTOKEN
- new_constant
- new_he
- new_logop
- new_warnings_bitfield
- next_symbol
- nextargv
- nextchar
- no_bareword_allowed
- no_fh_allowed
- no_op
- not_a_number
- nuke_stacks
- num_overflow
- oopsAV
- oopsHV
- op_clear
- op_const_sv
- op_getmad
- op_getmad_weak
- op_refcnt_dec
- op_refcnt_inc
- op_xmldump
- open_script
- opt_scalarhv
- pack_rec
- package
- package_version
- pad_add_name_sv
- pad_compname_type
- pad_peg
- padlist_dup
- parse_body
- parse_unicode_opts
- parser_free
- path_is_absolute
- peep
- pending_Slabs_to_ro
- pidgone
- pm_description
- pmop_xmldump
- pmruntime
- pmtrans
- populate_isa
- prepend_madprops
- printbuf
- process_special_blocks
- ptr_table_find
- put_byte
- qerror
- qsortsvu
- re_croak2
- readpipe_override
- ref_array_or_hash
- refcounted_he_value
- refkids
- refto
- reg
- reg_check_named_buff_matched
- reg_named_buff
- reg_named_buff_iter
- reg_namedseq
- reg_node
- reg_numbered_buff_fetch
- reg_numbered_buff_length
- reg_numbered_buff_store
- reg_qr_package
- reg_recode
- reg_scan_name
- reg_skipcomment
- reg_temp_copy
- reganode
- regatom
- regbranch
- regclass
- regcppop
- regcppush
- regcurly
- regdump_extflags
- reghop3
- reghop4
- reghopmaybe3
- reginclass
- reginsert
- regmatch
- regpiece
- regpposixcc
- regprop
- regrepeat
- regtail
- regtail_study
- regtry
- reguni
- regwhite
- report_evil_fh
- report_wrongway_fh
- require_tie_mod
- restore_magic
- rpeep
- rsignal_restore
- rsignal_save
- run_body
- run_user_filter
- rxres_free
- rxres_restore
- rxres_save
- same_dirent
- save_hek_flags
- save_lines
- save_magic
- save_pushptri32ptr
- save_scalar_at
- sawparens
- scalar
- scalar_mod_type
- scalarboolean
- scalarkids
- scalarseq
- scalarvoid
- scan_commit
- scan_const
- scan_formline
- scan_heredoc
- scan_ident
- scan_inputsymbol
- scan_pat
- scan_str
- scan_subst
- scan_trans
- scan_word
- search_const
- sequence
- sequence_num
- sequence_tail
- set_regclass_bit
- set_regclass_bit_fold
- share_hek_flags
- sighandler
- simplify_sort
- skipspace
- skipspace0
- skipspace1
- skipspace2
- softref2xv
- sortcv
- sortcv_stacked
- sortcv_xsub
- space_join_names_mortal
- start_force
- stdize_locale
- store_cop_label
- strip_return
- study_chunk
- sub_crush_depth
- sublex_done
- sublex_push
- sublex_start
- sv_2iuv_common
- sv_2iuv_non_preserve
- sv_add_backref
- sv_catxmlpv
- sv_catxmlpvn
- sv_catxmlsv
- sv_compile_2op_is_broken
- sv_del_backref
- sv_dup_common
- sv_dup_inc_multiple
- sv_exp_grow
- sv_free2
- sv_i_ncmp
- sv_kill_backrefs
- sv_ncmp
- sv_pos_b2u_midway
- sv_pos_u2b_cached
- sv_pos_u2b_forwards
- sv_pos_u2b_midway
- sv_release_COW
- sv_setsv_cow
- sv_unglob
- sv_xmlpeek
- swallow_bom
- swash_get
- tied_method
- to_byte_substr
- to_utf8_substr
- token_free
- token_getmad
- tokenize_use
- tokeq
- tokereport
- too_few_arguments
- too_many_arguments
- try_amagic_bin
- try_amagic_un
- uiv_2buf
- unpack_rec
- unreferenced_to_tmp_stack
- unshare_hek
- unshare_hek_or_pvn
- unwind_handler_stack
- update_debugger_info
- usage
- utf16_textfilter
- utf8_mg_len_cache_update
- utf8_mg_pos_cache_update
- utilize
- validate_suid
- varname
- visit
- vivify_defelem
- vivify_ref
- wait4pid
- watch
- with_queued_errors
- write_no_mem
- write_to_stderr
- xmldump_all
- xmldump_all_perl
- xmldump_attr
- xmldump_eval
- xmldump_form
- xmldump_indent
- xmldump_packsubs
- xmldump_packsubs_perl
- xmldump_sub
- xmldump_sub_perl
- xmldump_vindent
- xs_apiversion_bootcheck
- xs_version_bootcheck
- yyerror
- yylex
- yyparse
- yyunlex
- yywarn
AUTHORS¶
The autodocumentation system was originally added to the Perl core by Benjamin
Stuhl. Documentation is by whoever was kind enough to document their
functions.
SEE ALSO¶
perlguts, perlapi