js/src/jsinterp.h

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=8 sw=4 et tw=78:
   3  *
   4  * ***** BEGIN LICENSE BLOCK *****
   5  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   6  *
   7  * The contents of this file are subject to the Mozilla Public License Version
   8  * 1.1 (the "License"); you may not use this file except in compliance with
   9  * the License. You may obtain a copy of the License at
  10  * http://www.mozilla.org/MPL/
  11  *
  12  * Software distributed under the License is distributed on an "AS IS" basis,
  13  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  14  * for the specific language governing rights and limitations under the
  15  * License.
  16  *
  17  * The Original Code is Mozilla Communicator client code, released
  18  * March 31, 1998.
  19  *
  20  * The Initial Developer of the Original Code is
  21  * Netscape Communications Corporation.
  22  * Portions created by the Initial Developer are Copyright (C) 1998
  23  * the Initial Developer. All Rights Reserved.
  24  *
  25  * Contributor(s):
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  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either of the GNU General Public License Version 2 or later (the "GPL"),
  29  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  30  * in which case the provisions of the GPL or the LGPL are applicable instead
  31  * of those above. If you wish to allow use of your version of this file only
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  36  * the provisions above, a recipient may use your version of this file under
  37  * the terms of any one of the MPL, the GPL or the LGPL.
  38  *
  39  * ***** END LICENSE BLOCK ***** */
  40
  41 #ifndef jsinterp_h___
  42 #define jsinterp_h___
  43 /*
  44  * JS interpreter interface.
  45  */
  46 #include "jsprvtd.h"
  47 #include "jspubtd.h"
  48 #include "jsfun.h"
  49 #include "jsopcode.h"
  50 #include "jsscript.h"
  51
  52 JS_BEGIN_EXTERN_C
  53
  54 typedef struct JSFrameRegs {
  55     jsbytecode      *pc;            /* program counter */
  56     jsval           *sp;            /* stack pointer */
  57 } JSFrameRegs;
  58
  59 /*
  60  * JS stack frame, may be allocated on the C stack by native callers.  Always
  61  * allocated on cx->stackPool for calls from the interpreter to an interpreted
  62  * function.
  63  *
  64  * NB: This struct is manually initialized in jsinterp.c and jsiter.c.  If you
  65  * add new members, update both files.  But first, try to remove members.  The
  66  * sharp* and xml* members should be moved onto the stack as local variables
  67  * with well-known slots, if possible.
  68  */
  69 struct JSStackFrame {
  70     JSFrameRegs     *regs;
  71     jsval           *slots;         /* variables, locals and operand stack */
  72     JSObject        *callobj;       /* lazily created Call object */
  73     JSObject        *argsobj;       /* lazily created arguments object */
  74     JSObject        *varobj;        /* variables object, where vars go */
  75     JSObject        *callee;        /* function or script object */
  76     JSScript        *script;        /* script being interpreted */
  77     JSFunction      *fun;           /* function being called or null */
  78     JSObject        *thisp;         /* "this" pointer if in method */
  79     uintN           argc;           /* actual argument count */
  80     jsval           *argv;          /* base of argument stack slots */
  81     jsval           rval;           /* function return value */
  82     JSStackFrame    *down;          /* previous frame */
  83     void            *annotation;    /* used by Java security */
  84     JSObject        *scopeChain;    /* scope chain */
  85     uintN           sharpDepth;     /* array/object initializer depth */
  86     JSObject        *sharpArray;    /* scope for #n= initializer vars */
  87     uint32          flags;          /* frame flags -- see below */
  88     JSStackFrame    *dormantNext;   /* next dormant frame chain */
  89     JSObject        *xmlNamespace;  /* null or default xml namespace in E4X */
  90     JSObject        *blockChain;    /* active compile-time block scopes */
  91     JSStackFrame    *displaySave;   /* previous value of display entry for
  92                                        script->staticDepth */
  93 #ifdef DEBUG
  94     jsrefcount      pcDisabledSave; /* for balanced property cache control */
  95 #endif
  96 };
  97
  98 static JS_INLINE jsval *
  99 StackBase(JSStackFrame *fp)
 100 {
 101     return fp->slots + fp->script->nfixed;
 102 }
 103
 104 static JS_INLINE uintN
 105 GlobalVarCount(JSStackFrame *fp)
 106 {
 107     uintN n;
 108
 109     JS_ASSERT(!fp->fun);
 110     n = fp->script->nfixed;
 111     if (fp->script->regexpsOffset != 0)
 112         n -= JS_SCRIPT_REGEXPS(fp->script)->length;
 113     return n;
 114 }
 115
 116 typedef struct JSInlineFrame {
 117     JSStackFrame    frame;          /* base struct */
 118     JSFrameRegs     callerRegs;     /* parent's frame registers */
 119     void            *mark;          /* mark before inline frame */
 120     void            *hookData;      /* debugger call hook data */
 121     JSVersion       callerVersion;  /* dynamic version of calling script */
 122 } JSInlineFrame;
 123
 124 /* JS stack frame flags. */
 125 #define JSFRAME_CONSTRUCTING   0x01 /* frame is for a constructor invocation */
 126 #define JSFRAME_COMPUTED_THIS  0x02 /* frame.thisp was computed already */
 127 #define JSFRAME_ASSIGNING      0x04 /* a complex (not simplex JOF_ASSIGNING) op
 128                                        is currently assigning to a property */
 129 #define JSFRAME_DEBUGGER       0x08 /* frame for JS_EvaluateInStackFrame */
 130 #define JSFRAME_EVAL           0x10 /* frame for obj_eval */
 131 #define JSFRAME_ROOTED_ARGV    0x20 /* frame.argv is rooted by the caller */
 132 #define JSFRAME_YIELDING       0x40 /* js_Interpret dispatched JSOP_YIELD */
 133 #define JSFRAME_ITERATOR       0x80 /* trying to get an iterator for for-in */
 134 #define JSFRAME_POP_BLOCKS    0x100 /* scope chain contains blocks to pop */
 135 #define JSFRAME_GENERATOR     0x200 /* frame belongs to generator-iterator */
 136
 137 #define JSFRAME_OVERRIDE_SHIFT 24   /* override bit-set params; see jsfun.c */
 138 #define JSFRAME_OVERRIDE_BITS  8
 139
 140 #define JSFRAME_SPECIAL       (JSFRAME_DEBUGGER | JSFRAME_EVAL)
 141
 142 /*
 143  * Property cache with structurally typed capabilities for invalidation, for
 144  * polymorphic callsite method/get/set speedups.
 145  *
 146  * See bug https://bugzilla.mozilla.org/show_bug.cgi?id=365851.
 147  */
 148 #define PROPERTY_CACHE_LOG2     12
 149 #define PROPERTY_CACHE_SIZE     JS_BIT(PROPERTY_CACHE_LOG2)
 150 #define PROPERTY_CACHE_MASK     JS_BITMASK(PROPERTY_CACHE_LOG2)
 151
 152 /*
 153  * Add kshape rather than xor it to avoid collisions between nearby bytecode
 154  * that are evolving an object by setting successive properties, incrementing
 155  * the object's scope->shape on each set.
 156  */
 157 #define PROPERTY_CACHE_HASH(pc,kshape)                                        \
 158     (((((jsuword)(pc) >> PROPERTY_CACHE_LOG2) ^ (jsuword)(pc)) + (kshape)) &  \
 159      PROPERTY_CACHE_MASK)
 160
 161 #define PROPERTY_CACHE_HASH_PC(pc,kshape)                                     \
 162     PROPERTY_CACHE_HASH(pc, kshape)
 163
 164 #define PROPERTY_CACHE_HASH_ATOM(atom,obj,pobj)                               \
 165     PROPERTY_CACHE_HASH((jsuword)(atom) >> 2, OBJ_SHAPE(obj))
 166
 167 /*
 168  * Property cache value capability macros.
 169  */
 170 #define PCVCAP_PROTOBITS        4
 171 #define PCVCAP_PROTOSIZE        JS_BIT(PCVCAP_PROTOBITS)
 172 #define PCVCAP_PROTOMASK        JS_BITMASK(PCVCAP_PROTOBITS)
 173
 174 #define PCVCAP_SCOPEBITS        4
 175 #define PCVCAP_SCOPESIZE        JS_BIT(PCVCAP_SCOPEBITS)
 176 #define PCVCAP_SCOPEMASK        JS_BITMASK(PCVCAP_SCOPEBITS)
 177
 178 #define PCVCAP_TAGBITS          (PCVCAP_PROTOBITS + PCVCAP_SCOPEBITS)
 179 #define PCVCAP_TAGMASK          JS_BITMASK(PCVCAP_TAGBITS)
 180 #define PCVCAP_TAG(t)           ((t) & PCVCAP_TAGMASK)
 181
 182 #define PCVCAP_MAKE(t,s,p)      (((t) << PCVCAP_TAGBITS) |                    \
 183                                  ((s) << PCVCAP_PROTOBITS) |                  \
 184                                  (p))
 185 #define PCVCAP_SHAPE(t)         ((t) >> PCVCAP_TAGBITS)
 186
 187 #define SHAPE_OVERFLOW_BIT      JS_BIT(32 - PCVCAP_TAGBITS)
 188
 189 extern uint32
 190 js_GenerateShape(JSContext *cx, JSBool gcLocked);
 191
 192 struct JSPropCacheEntry {
 193     jsbytecode          *kpc;           /* pc if vcap tag is <= 1, else atom */
 194     jsuword             kshape;         /* key shape if pc, else obj for atom */
 195     jsuword             vcap;           /* value capability, see above */
 196     jsuword             vword;          /* value word, see PCVAL_* below */
 197 };
 198
 199 #if defined DEBUG_brendan || defined DEBUG_brendaneich
 200 #define JS_PROPERTY_CACHE_METERING 1
 201 #endif
 202
 203 typedef struct JSPropertyCache {
 204     JSPropCacheEntry    table[PROPERTY_CACHE_SIZE];
 205     JSBool              empty;
 206     jsrefcount          disabled;       /* signed for anti-underflow asserts */
 207 #ifdef JS_PROPERTY_CACHE_METERING
 208     uint32              fills;          /* number of cache entry fills */
 209     uint32              nofills;        /* couldn't fill (e.g. default get) */
 210     uint32              rofills;        /* set on read-only prop can't fill */
 211     uint32              disfills;       /* fill attempts on disabled cache */
 212     uint32              oddfills;       /* fill attempt after setter deleted */
 213     uint32              modfills;       /* fill that rehashed to a new entry */
 214     uint32              brandfills;     /* scope brandings to type structural
 215                                            method fills */
 216     uint32              noprotos;       /* resolve-returned non-proto pobj */
 217     uint32              longchains;     /* overlong scope and/or proto chain */
 218     uint32              recycles;       /* cache entries recycled by fills */
 219     uint32              pcrecycles;     /* pc-keyed entries recycled by atom-
 220                                            keyed fills */
 221     uint32              tests;          /* cache probes */
 222     uint32              pchits;         /* fast-path polymorphic op hits */
 223     uint32              protopchits;    /* pchits hitting immediate prototype */
 224     uint32              initests;       /* cache probes from JSOP_INITPROP */
 225     uint32              inipchits;      /* init'ing next property pchit case */
 226     uint32              inipcmisses;    /* init'ing next property pc misses */
 227     uint32              settests;       /* cache probes from JOF_SET opcodes */
 228     uint32              addpchits;      /* adding next property pchit case */
 229     uint32              setpchits;      /* setting existing property pchit */
 230     uint32              setpcmisses;    /* setting/adding property pc misses */
 231     uint32              slotchanges;    /* clasp->reserveSlots result variance-
 232                                            induced slot changes */
 233     uint32              setmisses;      /* JSOP_SET{NAME,PROP} total misses */
 234     uint32              idmisses;       /* slow-path key id == atom misses */
 235     uint32              komisses;       /* slow-path key object misses */
 236     uint32              vcmisses;       /* value capability misses */
 237     uint32              misses;         /* cache misses */
 238     uint32              flushes;        /* cache flushes */
 239     uint32              pcpurges;       /* shadowing purges on proto chain */
 240 # define PCMETER(x)     x
 241 #else
 242 # define PCMETER(x)     ((void)0)
 243 #endif
 244 } JSPropertyCache;
 245
 246 /*
 247  * Property cache value tagging/untagging macros.
 248  */
 249 #define PCVAL_OBJECT            0
 250 #define PCVAL_SLOT              1
 251 #define PCVAL_SPROP             2
 252
 253 #define PCVAL_TAGBITS           2
 254 #define PCVAL_TAGMASK           JS_BITMASK(PCVAL_TAGBITS)
 255 #define PCVAL_TAG(v)            ((v) & PCVAL_TAGMASK)
 256 #define PCVAL_CLRTAG(v)         ((v) & ~(jsuword)PCVAL_TAGMASK)
 257 #define PCVAL_SETTAG(v,t)       ((jsuword)(v) | (t))
 258
 259 #define PCVAL_NULL              0
 260 #define PCVAL_IS_NULL(v)        ((v) == PCVAL_NULL)
 261
 262 #define PCVAL_IS_OBJECT(v)      (PCVAL_TAG(v) == PCVAL_OBJECT)
 263 #define PCVAL_TO_OBJECT(v)      ((JSObject *) (v))
 264 #define OBJECT_TO_PCVAL(obj)    ((jsuword) (obj))
 265
 266 #define PCVAL_OBJECT_TO_JSVAL(v) OBJECT_TO_JSVAL(PCVAL_TO_OBJECT(v))
 267 #define JSVAL_OBJECT_TO_PCVAL(v) OBJECT_TO_PCVAL(JSVAL_TO_OBJECT(v))
 268
 269 #define PCVAL_IS_SLOT(v)        ((v) & PCVAL_SLOT)
 270 #define PCVAL_TO_SLOT(v)        ((jsuint)(v) >> 1)
 271 #define SLOT_TO_PCVAL(i)        (((jsuword)(i) << 1) | PCVAL_SLOT)
 272
 273 #define PCVAL_IS_SPROP(v)       (PCVAL_TAG(v) == PCVAL_SPROP)
 274 #define PCVAL_TO_SPROP(v)       ((JSScopeProperty *) PCVAL_CLRTAG(v))
 275 #define SPROP_TO_PCVAL(sprop)   PCVAL_SETTAG(sprop, PCVAL_SPROP)
 276
 277 /*
 278  * Fill property cache entry for key cx->fp->pc, optimized value word computed
 279  * from obj and sprop, and entry capability forged from 24-bit OBJ_SHAPE(obj),
 280  * 4-bit scopeIndex, and 4-bit protoIndex.
 281  */
 282 extern void
 283 js_FillPropertyCache(JSContext *cx, JSObject *obj, jsuword kshape,
 284                      uintN scopeIndex, uintN protoIndex,
 285                      JSObject *pobj, JSScopeProperty *sprop,
 286                      JSPropCacheEntry **entryp);
 287
 288 /*
 289  * Property cache lookup macros. PROPERTY_CACHE_TEST is designed to inline the
 290  * fast path in js_Interpret, so it makes "just-so" restrictions on parameters,
 291  * e.g. pobj and obj should not be the same variable, since for JOF_PROP-mode
 292  * opcodes, obj must not be changed because of a cache miss.
 293  *
 294  * On return from PROPERTY_CACHE_TEST, if atom is null then obj points to the
 295  * scope chain element in which the property was found, pobj is locked, and
 296  * entry is valid. If atom is non-null then no object is locked but entry is
 297  * still set correctly for use, e.g., by js_FillPropertyCache and atom should
 298  * be used as the id to find.
 299  *
 300  * We must lock pobj on a hit in order to close races with threads that might
 301  * be deleting a property from its scope, or otherwise invalidating property
 302  * caches (on all threads) by re-generating scope->shape.
 303  */
 304 #define PROPERTY_CACHE_TEST(cx, pc, obj, pobj, entry, atom)                   \
 305     do {                                                                      \
 306         JSPropertyCache *cache_ = &JS_PROPERTY_CACHE(cx);                     \
 307         uint32 kshape_ = (JS_ASSERT(OBJ_IS_NATIVE(obj)), OBJ_SHAPE(obj));     \
 308         entry = &cache_->table[PROPERTY_CACHE_HASH_PC(pc, kshape_)];          \
 309         PCMETER(cache_->tests++);                                             \
 310         JS_ASSERT(&obj != &pobj);                                             \
 311         if (entry->kpc == pc && entry->kshape == kshape_) {                   \
 312             JSObject *tmp_;                                                   \
 313             pobj = obj;                                                       \
 314             JS_LOCK_OBJ(cx, pobj);                                            \
 315             JS_ASSERT(PCVCAP_TAG(entry->vcap) <= 1);                          \
 316             if (PCVCAP_TAG(entry->vcap) == 1 &&                               \
 317                 (tmp_ = LOCKED_OBJ_GET_PROTO(pobj)) != NULL &&                \
 318                 OBJ_IS_NATIVE(tmp_)) {                                        \
 319                 JS_UNLOCK_OBJ(cx, pobj);                                      \
 320                 pobj = tmp_;                                                  \
 321                 JS_LOCK_OBJ(cx, pobj);                                        \
 322             }                                                                 \
 323             if (PCVCAP_SHAPE(entry->vcap) == OBJ_SHAPE(pobj)) {               \
 324                 PCMETER(cache_->pchits++);                                    \
 325                 PCMETER(!PCVCAP_TAG(entry->vcap) || cache_->protopchits++);   \
 326                 pobj = OBJ_SCOPE(pobj)->object;                               \
 327                 atom = NULL;                                                  \
 328                 break;                                                        \
 329             }                                                                 \
 330             JS_UNLOCK_OBJ(cx, pobj);                                          \
 331         }                                                                     \
 332         atom = js_FullTestPropertyCache(cx, pc, &obj, &pobj, &entry);         \
 333         if (atom)                                                             \
 334             PCMETER(cache_->misses++);                                        \
 335     } while (0)
 336
 337 extern JSAtom *
 338 js_FullTestPropertyCache(JSContext *cx, jsbytecode *pc,
 339                          JSObject **objp, JSObject **pobjp,
 340                          JSPropCacheEntry **entryp);
 341
 342 extern void
 343 js_FlushPropertyCache(JSContext *cx);
 344
 345 extern void
 346 js_FlushPropertyCacheForScript(JSContext *cx, JSScript *script);
 347
 348 extern void
 349 js_DisablePropertyCache(JSContext *cx);
 350
 351 extern void
 352 js_EnablePropertyCache(JSContext *cx);
 353
 354 /*
 355  * Interpreter stack arena-pool alloc and free functions.
 356  */
 357 extern JS_FRIEND_API(jsval *)
 358 js_AllocStack(JSContext *cx, uintN nslots, void **markp);
 359
 360 extern JS_FRIEND_API(void)
 361 js_FreeStack(JSContext *cx, void *mark);
 362
 363 /*
 364  * Refresh and return fp->scopeChain.  It may be stale if block scopes are
 365  * active but not yet reflected by objects in the scope chain.  If a block
 366  * scope contains a with, eval, XML filtering predicate, or similar such
 367  * dynamically scoped construct, then compile-time block scope at fp->blocks
 368  * must reflect at runtime.
 369  */
 370 extern JSObject *
 371 js_GetScopeChain(JSContext *cx, JSStackFrame *fp);
 372
 373 /*
 374  * Given a context and a vector of [callee, this, args...] for a function that
 375  * was specified with a JSFUN_THISP_PRIMITIVE flag, get the primitive value of
 376  * |this| into *thisvp. In doing so, if |this| is an object, insist it is an
 377  * instance of clasp and extract its private slot value to return via *thisvp.
 378  *
 379  * NB: this function loads and uses *vp before storing *thisvp, so the two may
 380  * alias the same jsval.
 381  */
 382 extern JSBool
 383 js_GetPrimitiveThis(JSContext *cx, jsval *vp, JSClass *clasp, jsval *thisvp);
 384
 385 /*
 386  * For a call with arguments argv including argv[-1] (nominal |this|) and
 387  * argv[-2] (callee) replace null |this| with callee's parent, replace
 388  * primitive values with the equivalent wrapper objects and censor activation
 389  * objects as, per ECMA-262, they may not be referred to by |this|. argv[-1]
 390  * must not be a JSVAL_VOID.
 391  */
 392 extern JSObject *
 393 js_ComputeThis(JSContext *cx, JSBool lazy, jsval *argv);
 394
 395 extern const uint16 js_PrimitiveTestFlags[];
 396
 397 #define PRIMITIVE_THIS_TEST(fun,thisv)                                        \
 398     (JS_ASSERT(!JSVAL_IS_VOID(thisv)),                                        \
 399      JSFUN_THISP_TEST(JSFUN_THISP_FLAGS((fun)->flags),                        \
 400                       js_PrimitiveTestFlags[JSVAL_TAG(thisv) - 1]))
 401
 402 /*
 403  * NB: js_Invoke requires that cx is currently running JS (i.e., that cx->fp
 404  * is non-null), and that vp points to the callee, |this| parameter, and
 405  * actual arguments of the call. [vp .. vp + 2 + argc) must belong to the last
 406  * JS stack segment that js_AllocStack allocated. The function may use the
 407  * space available after vp + 2 + argc in the stack segment for temporaries,
 408  * so the caller should not use that space for values that must be preserved
 409  * across the call.
 410  */
 411 extern JS_FRIEND_API(JSBool)
 412 js_Invoke(JSContext *cx, uintN argc, jsval *vp, uintN flags);
 413
 414 /*
 415  * Consolidated js_Invoke flags simply rename certain JSFRAME_* flags, so that
 416  * we can share bits stored in JSStackFrame.flags and passed to:
 417  *
 418  *   js_Invoke
 419  *   js_InternalInvoke
 420  *   js_ValueToFunction
 421  *   js_ValueToFunctionObject
 422  *   js_ValueToCallableObject
 423  *   js_ReportIsNotFunction
 424  *
 425  * See jsfun.h for the latter four and flag renaming macros.
 426  */
 427 #define JSINVOKE_CONSTRUCT      JSFRAME_CONSTRUCTING
 428 #define JSINVOKE_ITERATOR       JSFRAME_ITERATOR
 429
 430 /*
 431  * Mask to isolate construct and iterator flags for use with jsfun.h functions.
 432  */
 433 #define JSINVOKE_FUNFLAGS       (JSINVOKE_CONSTRUCT | JSINVOKE_ITERATOR)
 434
 435 /*
 436  * "Internal" calls may come from C or C++ code using a JSContext on which no
 437  * JS is running (!cx->fp), so they may need to push a dummy JSStackFrame.
 438  */
 439 #define js_InternalCall(cx,obj,fval,argc,argv,rval)                           \
 440     js_InternalInvoke(cx, obj, fval, 0, argc, argv, rval)
 441
 442 #define js_InternalConstruct(cx,obj,fval,argc,argv,rval)                      \
 443     js_InternalInvoke(cx, obj, fval, JSINVOKE_CONSTRUCT, argc, argv, rval)
 444
 445 extern JSBool
 446 js_InternalInvoke(JSContext *cx, JSObject *obj, jsval fval, uintN flags,
 447                   uintN argc, jsval *argv, jsval *rval);
 448
 449 extern JSBool
 450 js_InternalGetOrSet(JSContext *cx, JSObject *obj, jsid id, jsval fval,
 451                     JSAccessMode mode, uintN argc, jsval *argv, jsval *rval);
 452
 453 extern JSBool
 454 js_Execute(JSContext *cx, JSObject *chain, JSScript *script,
 455            JSStackFrame *down, uintN flags, jsval *result);
 456
 457 extern JSBool
 458 js_InvokeConstructor(JSContext *cx, uintN argc, JSBool clampReturn, jsval *vp);
 459
 460 extern JSBool
 461 js_Interpret(JSContext *cx);
 462
 463 #define JSPROP_INITIALIZER 0x100   /* NB: Not a valid property attribute. */
 464
 465 extern JSBool
 466 js_CheckRedeclaration(JSContext *cx, JSObject *obj, jsid id, uintN attrs,
 467                       JSObject **objp, JSProperty **propp);
 468
 469 extern JSBool
 470 js_StrictlyEqual(JSContext *cx, jsval lval, jsval rval);
 471
 472 /*
 473  * JS_LONE_INTERPRET indicates that the compiler should see just the code for
 474  * the js_Interpret function when compiling jsinterp.cpp. The rest of the code
 475  * from the file should be visible only when compiling jsinvoke.cpp. It allows
 476  * platform builds to optimize selectively js_Interpret when the granularity
 477  * of the optimizations with the given compiler is a compilation unit.
 478  *
 479  * JS_STATIC_INTERPRET is the modifier for functions defined in jsinterp.cpp
 480  * that only js_Interpret calls. When JS_LONE_INTERPRET is true all such
 481  * functions are declared below.
 482  */
 483 #ifndef JS_LONE_INTERPRET
 484 # ifdef _MSC_VER
 485 #  define JS_LONE_INTERPRET 0
 486 # else
 487 #  define JS_LONE_INTERPRET 1
 488 # endif
 489 #endif
 490
 491 #if !JS_LONE_INTERPRET
 492 # define JS_STATIC_INTERPRET    static
 493 #else
 494 # define JS_STATIC_INTERPRET
 495
 496 extern jsval *
 497 js_AllocRawStack(JSContext *cx, uintN nslots, void **markp);
 498
 499 extern void
 500 js_FreeRawStack(JSContext *cx, void *mark);
 501
 502 /*
 503  * ECMA requires "the global object", but in embeddings such as the browser,
 504  * which have multiple top-level objects (windows, frames, etc. in the DOM),
 505  * we prefer fun's parent.  An example that causes this code to run:
 506  *
 507  *   // in window w1
 508  *   function f() { return this }
 509  *   function g() { return f }
 510  *
 511  *   // in window w2
 512  *   var h = w1.g()
 513  *   alert(h() == w1)
 514  *
 515  * The alert should display "true".
 516  */
 517 extern JSObject *
 518 js_ComputeGlobalThis(JSContext *cx, JSBool lazy, jsval *argv);
 519
 520 extern JSBool
 521 js_EnterWith(JSContext *cx, jsint stackIndex);
 522
 523 extern void
 524 js_LeaveWith(JSContext *cx);
 525
 526 extern JSClass *
 527 js_IsActiveWithOrBlock(JSContext *cx, JSObject *obj, int stackDepth);
 528
 529 extern jsint
 530 js_CountWithBlocks(JSContext *cx, JSStackFrame *fp);
 531
 532 /*
 533  * Unwind block and scope chains to match the given depth. The function sets
 534  * fp->sp on return to stackDepth.
 535  */
 536 extern JSBool
 537 js_UnwindScope(JSContext *cx, JSStackFrame *fp, jsint stackDepth,
 538                JSBool normalUnwind);
 539
 540 extern JSBool
 541 js_InternNonIntElementId(JSContext *cx, JSObject *obj, jsval idval, jsid *idp);
 542
 543 extern JSBool
 544 js_OnUnknownMethod(JSContext *cx, jsval *vp);
 545
 546 /*
 547  * Find the results of incrementing or decrementing *vp. For pre-increments,
 548  * both *vp and *vp2 will contain the result on return. For post-increments,
 549  * vp will contain the original value converted to a number and vp2 will get
 550  * the result. Both vp and vp2 must be roots.
 551  */
 552 extern JSBool
 553 js_DoIncDec(JSContext *cx, const JSCodeSpec *cs, jsval *vp, jsval *vp2);
 554
 555 /*
 556  * Opcode tracing helper. When len is not 0, cx->fp->regs->pc[-len] gives the
 557  * previous opcode.
 558  */
 559 extern void
 560 js_TraceOpcode(JSContext *cx, jsint len);
 561
 562 /*
 563  * JS_OPMETER helper functions.
 564  */
 565 extern void
 566 js_MeterOpcodePair(JSOp op1, JSOp op2);
 567
 568 extern void
 569 js_MeterSlotOpcode(JSOp op, uint32 slot);
 570
 571 #endif /* JS_LONE_INTERPRET */
 572
 573 JS_END_EXTERN_C
 574
 575 #endif /* jsinterp_h___ */