/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* 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
* http://www.mozilla.org/MPL/
*
* 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
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* the provisions above, a recipient may use your version of this file under
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*
* ***** END LICENSE BLOCK ***** */
#ifndef jsfun_h___
#define jsfun_h___
/*
* JS function definitions.
*/
#include "jsprvtd.h"
#include "jspubtd.h"
#include "jsobj.h"
JS_BEGIN_EXTERN_C
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_TRACEABLE 0x2000 /* can trace across calls to this native
function; use FUN_TRCINFO if set,
FUN_CLASP if unset */
#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) (&(fun)->object)
#define FUN_KIND(fun) ((fun)->flags & JSFUN_KINDMASK)
#define FUN_SET_KIND(fun,k) ((fun)->flags = ((fun)->flags & ~JSFUN_KINDMASK) | (k))
#define FUN_INTERPRETED(fun) (FUN_KIND(fun) >= JSFUN_INTERPRETED)
#define FUN_FLAT_CLOSURE(fun)(FUN_KIND(fun) == JSFUN_FLAT_CLOSURE)
#define FUN_NULL_CLOSURE(fun)(FUN_KIND(fun) == JSFUN_NULL_CLOSURE)
#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 \
: NULL)
#define FUN_MINARGS(fun) (((fun)->flags & JSFUN_FAST_NATIVE) \
? 0 \
: (fun)->nargs)
#define FUN_CLASP(fun) (JS_ASSERT(!FUN_INTERPRETED(fun)), \
fun->u.n.clasp)
#define FUN_TRCINFO(fun) (JS_ASSERT(!FUN_INTERPRETED(fun)), \
JS_ASSERT((fun)->flags & JSFUN_TRACEABLE), \
fun->u.n.trcinfo)
struct JSFunction {
JSObject object; /* GC'ed object header */
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 */
JSTraceableNative *trcinfo; /* tracer metadata; can be first
element of array */
} 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 */
#ifdef __cplusplus
bool optimizedClosure() { return FUN_KIND(this) > JSFUN_INTERPRETED; }
bool needsWrapper() { return FUN_NULL_CLOSURE(this) && u.i.skipmin != 0; }
uintN countArgsAndVars() const {
JS_ASSERT(FUN_INTERPRETED(this));
return nargs + u.i.nvars;
}
uintN countLocalNames() const {
JS_ASSERT(FUN_INTERPRETED(this));
return countArgsAndVars() + u.i.nupvars;
}
bool hasLocalNames() const {
JS_ASSERT(FUN_INTERPRETED(this));
return countLocalNames() != 0;
}
#endif
};
/*
* Traceable native. This expands to a JSFunctionSpec initializer (like JS_FN
* in jsapi.h). fastcall is a JSFastNative; trcinfo is a JSTraceableNative *.
*/
#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, \
(flags) | JSFUN_FAST_NATIVE | JSFUN_STUB_GSOPS | JSFUN_TRACEABLE)
#else
# define JS_TN(name,fastcall,nargs,flags,trcinfo) \
JS_FN(name, fastcall, nargs, flags)
#endif
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;
#define HAS_FUNCTION_CLASS(obj) (STOBJ_GET_CLASS(obj) == &js_FunctionClass)
/*
* NB: jsapi.h and jsobj.h must be included before any call to this macro.
*/
#define VALUE_IS_FUNCTION(cx, v) \
(!JSVAL_IS_PRIMITIVE(v) && HAS_FUNCTION_CLASS(JSVAL_TO_OBJECT(v)))
/*
* Macro to access the private slot of the function object after the slot is
* initialized.
*/
#define GET_FUNCTION_PRIVATE(cx, funobj) \
(JS_ASSERT(HAS_FUNCTION_CLASS(funobj)), \
(JSFunction *) OBJ_GET_PRIVATE(cx, funobj))
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_CloneFunctionObject(JSContext *cx, JSFunction *fun, JSObject *parent);
extern JS_REQUIRES_STACK JSObject *
js_NewFlatClosure(JSContext *cx, JSFunction *fun);
extern JS_REQUIRES_STACK JSObject *
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_CONSTRUCT JSINVOKE_CONSTRUCT
#define JSV2F_ITERATOR JSINVOKE_ITERATOR
#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 JS_FRIEND_API(JSBool)
js_PutCallObject(JSContext *cx, JSStackFrame *fp);
extern JSBool
js_GetCallArg(JSContext *cx, JSObject *obj, jsid id, jsval *vp);
extern JS_REQUIRES_STACK JSBool
js_GetCallVar(JSContext *cx, JSObject *obj, jsval id, jsval *vp);
/*
* Slower version of js_GetCallVar used when call_resolve detects an attempt to
* leak an optimized closure via indirect or debugger eval.
*/
extern JS_REQUIRES_STACK 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 JS_FRIEND_API(JSBool)
js_PutArgsObject(JSContext *cx, JSStackFrame *fp);
extern JSBool
js_XDRFunctionObject(JSXDRState *xdr, JSObject **objp);
typedef enum JSLocalKind {
JSLOCAL_NONE,
JSLOCAL_ARG,
JSLOCAL_VAR,
JSLOCAL_CONST,
JSLOCAL_UPVAR
} 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 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 JS_REQUIRES_STACK JSBool
js_fun_apply(JSContext *cx, uintN argc, jsval *vp);
extern JS_REQUIRES_STACK JSBool
js_fun_call(JSContext *cx, uintN argc, jsval *vp);
JS_END_EXTERN_C
#endif /* jsfun_h___ */