Skip to content


Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: r37a3
Fetching contributors…

Cannot retrieve contributors at this time

494 lines (417 sloc) 18.875 kb
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
* Contributor(s):
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
* ***** END LICENSE BLOCK ***** */
#ifndef jsfun_h___
#define jsfun_h___
* JS function definitions.
#include "jsprvtd.h"
#include "jspubtd.h"
#include "jsobj.h"
typedef struct JSLocalNameMap JSLocalNameMap;
* Depending on the number of arguments and variables in the function their
* names and attributes are stored either as a single atom or as an array of
* tagged atoms (when there are few locals) or as a hash-based map (when there
* are many locals). In the first 2 cases the lowest bit of the atom is used
* as a tag to distinguish const from var. See jsfun.c for details.
typedef union JSLocalNames {
jsuword taggedAtom;
jsuword *array;
JSLocalNameMap *map;
} JSLocalNames;
* The high two bits of JSFunction.flags encode whether the function is native
* or interpreted, and if interpreted, what kind of optimized closure form (if
* any) it might be.
* 00 not interpreted
* 01 interpreted, neither flat nor null closure
* 10 interpreted, flat closure
* 11 interpreted, null closure
* FUN_FLAT_CLOSURE implies FUN_INTERPRETED and u.i.script->upvarsOffset != 0.
* FUN_NULL_CLOSURE implies FUN_INTERPRETED and u.i.script->upvarsOffset == 0.
* FUN_INTERPRETED but not FUN_FLAT_CLOSURE and u.i.script->upvarsOffset != 0
* is an Algol-like function expression or nested function, i.e., a function
* that never escapes upward or downward (heapward), and is only ever called.
* Finally, FUN_INTERPRETED and u.i.script->upvarsOffset == 0 could be either
* a non-closure (a global function definition, or any function that uses no
* outer names), or a closure of an escaping function that uses outer names
* whose values can't be snapshot (because the outer names could be reassigned
* after the closure is formed, or because assignments could not be analyzed
* due to with or eval).
* Such a hard-case function must use JSOP_NAME, etc., and reify outer function
* activations' call objects, etc. if it's not a global function.
* NB: JSFUN_EXPR_CLOSURE reuses JSFUN_STUB_GSOPS, which is an API request flag
* bit only, never stored in fun->flags.
* If we need more bits in the future, all flags for FUN_INTERPRETED functions
* can move to u.i.script->flags. For now we use function flag bits to minimize
* pointer-chasing.
#define JSFUN_EXPR_CLOSURE 0x1000 /* expression closure: function(x) x*x */
#define JSFUN_TRCINFO 0x2000 /* when set, u.n.trcinfo is non-null,
JSFunctionSpec::call points to a
JSNativeTraceInfo. */
#define JSFUN_INTERPRETED 0x4000 /* use u.i if kind >= this value else u.n */
#define JSFUN_FLAT_CLOSURE 0x8000 /* flag (aka "display") closure */
#define JSFUN_NULL_CLOSURE 0xc000 /* null closure entrains no scope chain */
#define JSFUN_KINDMASK 0xc000 /* encode interp vs. native and closure
optimization level -- see above */
#define FUN_OBJECT(fun) (static_cast<JSObject *>(fun))
#define FUN_KIND(fun) ((fun)->flags & JSFUN_KINDMASK)
#define FUN_SET_KIND(fun,k) ((fun)->flags = ((fun)->flags & ~JSFUN_KINDMASK) | (k))
#define FUN_SLOW_NATIVE(fun) (!FUN_INTERPRETED(fun) && !((fun)->flags & JSFUN_FAST_NATIVE))
#define FUN_SCRIPT(fun) (FUN_INTERPRETED(fun) ? (fun)->u.i.script : NULL)
#define FUN_NATIVE(fun) (FUN_SLOW_NATIVE(fun) ? (fun)->u.n.native : NULL)
#define FUN_FAST_NATIVE(fun) (((fun)->flags & JSFUN_FAST_NATIVE) \
? (JSFastNative) (fun)->u.n.native \
#define FUN_MINARGS(fun) (((fun)->flags & JSFUN_FAST_NATIVE) \
? 0 \
: (fun)->nargs)
JS_ASSERT((fun)->flags & JSFUN_TRCINFO), \
struct JSFunction : public JSObject
uint16 nargs; /* maximum number of specified arguments,
reflected as f.length/f.arity */
uint16 flags; /* flags, see JSFUN_* below and in jsapi.h */
union {
struct {
uint16 extra; /* number of arg slots for local GC roots */
uint16 spare; /* reserved for future use */
JSNative native; /* native method pointer or null */
JSClass *clasp; /* class of objects constructed
by this function */
JSNativeTraceInfo *trcinfo;
} n;
struct {
uint16 nvars; /* number of local variables */
uint16 nupvars; /* number of upvars (computable from script
but here for faster access) */
uint16 skipmin; /* net skip amount up (toward zero) from
script->staticLevel to nearest upvar,
including upvars in nested functions */
JSPackedBool wrapper; /* true if this function is a wrapper that
rewrites bytecode optimized for a function
judged non-escaping by the compiler, which
then escaped via the debugger or a rogue
indirect eval; if true, then this function
object's proto is the wrapped object */
JSScript *script; /* interpreted bytecode descriptor or null */
JSLocalNames names; /* argument and variable names */
} i;
} u;
JSAtom *atom; /* name for diagnostics and decompiling */
bool optimizedClosure() const { return FUN_KIND(this) > JSFUN_INTERPRETED; }
bool needsWrapper() const { return FUN_NULL_CLOSURE(this) && u.i.skipmin != 0; }
uintN countVars() const {
return u.i.nvars;
uintN countArgsAndVars() const {
return nargs + u.i.nvars;
uintN countLocalNames() const {
return countArgsAndVars() + u.i.nupvars;
bool hasLocalNames() const {
return countLocalNames() != 0;
int sharpSlotBase(JSContext *cx);
* If fun's formal parameters include any duplicate names, return one
* of them (chosen arbitrarily). If they are all unique, return NULL.
JSAtom *findDuplicateFormal() const;
uint32 countInterpretedReservedSlots() const;
bool mightEscape() const {
return FUN_INTERPRETED(this) && (FUN_FLAT_CLOSURE(this) || u.i.nupvars == 0);
* Trace-annotated native. This expands to a JSFunctionSpec initializer (like
* JS_FN in jsapi.h). fastcall is a JSFastNative; trcinfo is a
* JSNativeTraceInfo*.
#ifdef JS_TRACER
/* MSVC demands the intermediate (void *) cast here. */
# define JS_TN(name,fastcall,nargs,flags,trcinfo) \
JS_FN(name, JS_DATA_TO_FUNC_PTR(JSNative, trcinfo), nargs, \
# define JS_TN(name,fastcall,nargs,flags,trcinfo) \
JS_FN(name, fastcall, nargs, flags)
extern JSClass js_ArgumentsClass;
extern JS_FRIEND_DATA(JSClass) js_CallClass;
extern JSClass js_DeclEnvClass;
/* JS_FRIEND_DATA so that VALUE_IS_FUNCTION is callable from the shell. */
extern JS_FRIEND_DATA(JSClass) js_FunctionClass;
inline bool
JSObject::isFunction() const
return getClass() == &js_FunctionClass;
#define HAS_FUNCTION_CLASS(obj) (obj)->isFunction()
* NB: jsapi.h and jsobj.h must be included before any call to this macro.
#define VALUE_IS_FUNCTION(cx, v) \
* Macro to access the private slot of the function object after the slot is
* initialized.
#define GET_FUNCTION_PRIVATE(cx, funobj) \
(JSFunction *) (funobj)->getPrivate())
* Return true if this is a compiler-created internal function accessed by
* its own object. Such a function object must not be accessible to script
* or embedding code.
inline bool
js_IsInternalFunctionObject(JSObject *funobj)
JSFunction *fun = (JSFunction *) funobj->getPrivate();
return funobj == fun && (fun->flags & JSFUN_LAMBDA) && !funobj->getParent();
namespace js { struct ArgsPrivateNative; }
inline js::ArgsPrivateNative *
js_GetArgsPrivateNative(JSObject *argsobj)
JS_ASSERT(STOBJ_GET_CLASS(argsobj) == &js_ArgumentsClass);
uintptr_t p = (uintptr_t) argsobj->getPrivate();
return (js::ArgsPrivateNative *) (p & 2 ? p & ~2 : NULL);
extern JSObject *
js_InitFunctionClass(JSContext *cx, JSObject *obj);
extern JSObject *
js_InitArgumentsClass(JSContext *cx, JSObject *obj);
extern JSFunction *
js_NewFunction(JSContext *cx, JSObject *funobj, JSNative native, uintN nargs,
uintN flags, JSObject *parent, JSAtom *atom);
extern void
js_TraceFunction(JSTracer *trc, JSFunction *fun);
extern void
js_FinalizeFunction(JSContext *cx, JSFunction *fun);
extern JSObject * JS_FASTCALL
js_CloneFunctionObject(JSContext *cx, JSFunction *fun, JSObject *parent,
JSObject *proto);
inline JSObject *
CloneFunctionObject(JSContext *cx, JSFunction *fun, JSObject *parent)
JSObject *proto;
if (!js_GetClassPrototype(cx, parent, JSProto_Function, &proto))
return NULL;
return js_CloneFunctionObject(cx, fun, parent, proto);
js_NewFlatClosure(JSContext *cx, JSFunction *fun);
js_NewDebuggableFlatClosure(JSContext *cx, JSFunction *fun);
extern JSFunction *
js_DefineFunction(JSContext *cx, JSObject *obj, JSAtom *atom, JSNative native,
uintN nargs, uintN flags);
* Flags for js_ValueToFunction and js_ReportIsNotFunction. We depend on the
* fact that JSINVOKE_CONSTRUCT (aka JSFRAME_CONSTRUCTING) is 1, and test that
* with #if/#error in jsfun.c.
#define JSV2F_SEARCH_STACK 0x10000
extern JSFunction *
js_ValueToFunction(JSContext *cx, jsval *vp, uintN flags);
extern JSObject *
js_ValueToFunctionObject(JSContext *cx, jsval *vp, uintN flags);
extern JSObject *
js_ValueToCallableObject(JSContext *cx, jsval *vp, uintN flags);
extern void
js_ReportIsNotFunction(JSContext *cx, jsval *vp, uintN flags);
extern JSObject *
js_GetCallObject(JSContext *cx, JSStackFrame *fp);
extern JSObject * JS_FASTCALL
js_CreateCallObjectOnTrace(JSContext *cx, JSFunction *fun, JSObject *callee, JSObject *scopeChain);
extern void
js_PutCallObject(JSContext *cx, JSStackFrame *fp);
js_PutCallObjectOnTrace(JSContext *cx, JSObject *scopeChain, uint32 nargs, jsval *argv,
uint32 nvars, jsval *slots);
extern JSFunction *
js_GetCallObjectFunction(JSObject *obj);
extern JSBool
js_GetCallArg(JSContext *cx, JSObject *obj, jsid id, jsval *vp);
extern JSBool
js_GetCallVar(JSContext *cx, JSObject *obj, jsid id, jsval *vp);
extern JSBool
SetCallArg(JSContext *cx, JSObject *obj, jsid id, jsval *vp);
extern JSBool
SetCallVar(JSContext *cx, JSObject *obj, jsid id, jsval *vp);
* js_SetCallArg and js_SetCallVar are extern fastcall copies of the setter
* functions. These versions are required in order to set call vars from traces.
* The normal versions must not be fastcall because they are stored in the
* property ops map.
js_SetCallArg(JSContext *cx, JSObject *obj, jsid id, jsval v);
js_SetCallVar(JSContext *cx, JSObject *obj, jsid id, jsval v);
* Slower version of js_GetCallVar used when call_resolve detects an attempt to
* leak an optimized closure via indirect or debugger eval.
extern JSBool
js_GetCallVarChecked(JSContext *cx, JSObject *obj, jsid id, jsval *vp);
extern JSBool
js_GetArgsValue(JSContext *cx, JSStackFrame *fp, jsval *vp);
extern JSBool
js_GetArgsProperty(JSContext *cx, JSStackFrame *fp, jsid id, jsval *vp);
extern JSObject *
js_GetArgsObject(JSContext *cx, JSStackFrame *fp);
extern void
js_PutArgsObject(JSContext *cx, JSStackFrame *fp);
inline bool
js_IsNamedLambda(JSFunction *fun) { return (fun->flags & JSFUN_LAMBDA) && fun->atom; }
* Reserved slot structure for Arguments objects:
* JSSLOT_PRIVATE - the corresponding frame until the frame exits.
* JSSLOT_ARGS_LENGTH - the number of actual arguments and a flag indicating
* whether arguments.length was overwritten.
* JSSLOT_ARGS_CALLEE - the arguments.callee value or JSVAL_HOLE if that was
* overwritten.
* JSSLOT_ARGS_COPY_START .. - room to store the corresponding arguments after
* the frame exists. The slot's value will be JSVAL_HOLE
* if arguments[i] was deleted or overwritten.
/* Number of extra fixed slots besides JSSLOT_PRIVATE. */
* JSSLOT_ARGS_LENGTH stores ((argc << 1) | overwritten_flag) as int jsval.
* Thus (JS_ARGS_LENGTH_MAX << 1) | 1 must fit JSVAL_INT_MAX. To assert that
* we check first that the shift does not overflow uint32.
js_IsOverriddenArgsLength(JSObject *obj)
JS_ASSERT(STOBJ_GET_CLASS(obj) == &js_ArgumentsClass);
jsval v = obj->fslots[JSSLOT_ARGS_LENGTH];
return (JSVAL_TO_INT(v) & 1) != 0;
extern JSBool
js_XDRFunctionObject(JSXDRState *xdr, JSObject **objp);
typedef enum JSLocalKind {
} JSLocalKind;
extern JSBool
js_AddLocal(JSContext *cx, JSFunction *fun, JSAtom *atom, JSLocalKind kind);
* Look up an argument or variable name returning its kind when found or
* JSLOCAL_NONE when no such name exists. When indexp is not null and the name
* exists, *indexp will receive the index of the corresponding argument or
* variable.
extern JSLocalKind
js_LookupLocal(JSContext *cx, JSFunction *fun, JSAtom *atom, uintN *indexp);
* Functions to work with local names as an array of words.
* js_GetLocalNameArray returns the array, or null if we are out of memory.
* This function must be called only when fun->hasLocalNames().
* The supplied pool is used to allocate the returned array, so the caller is
* obligated to mark and release to free it.
* The elements of the array with index less than fun->nargs correspond to the
* names of function formal parameters. An index >= fun->nargs addresses a var
* binding. Use JS_LOCAL_NAME_TO_ATOM to convert array's element to an atom
* pointer. This pointer can be null when the element is for a formal parameter
* corresponding to a destructuring pattern.
* If nameWord does not name a formal parameter, use JS_LOCAL_NAME_IS_CONST to
* check if nameWord corresponds to the const declaration.
extern JS_FRIEND_API(jsuword *)
js_GetLocalNameArray(JSContext *cx, JSFunction *fun, struct JSArenaPool *pool);
#define JS_LOCAL_NAME_TO_ATOM(nameWord) \
((JSAtom *) ((nameWord) & ~(jsuword) 1))
#define JS_LOCAL_NAME_IS_CONST(nameWord) \
((((nameWord) & (jsuword) 1)) != 0)
extern void
js_FreezeLocalNames(JSContext *cx, JSFunction *fun);
extern JSBool
js_fun_apply(JSContext *cx, uintN argc, jsval *vp);
extern JSBool
js_fun_call(JSContext *cx, uintN argc, jsval *vp);
#endif /* jsfun_h___ */
Jump to Line
Something went wrong with that request. Please try again.