The Tor Browser: js/xpconnect/src/xpcpublic.h@a63d609f5ebe

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

     2 /* vim: set ts=8 sts=4 et sw=4 tw=99: */

     3 /* This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #ifndef xpcpublic_h

     8 #define xpcpublic_h

    10 #include "jsapi.h"

    11 #include "jsproxy.h"

    12 #include "js/HeapAPI.h"

    13 #include "js/GCAPI.h"

    15 #include "nsISupports.h"

    16 #include "nsIURI.h"

    17 #include "nsIPrincipal.h"

    18 #include "nsWrapperCache.h"

    19 #include "nsStringGlue.h"

    20 #include "nsTArray.h"

    21 #include "mozilla/dom/JSSlots.h"

    22 #include "nsMathUtils.h"

    23 #include "nsStringBuffer.h"

    24 #include "mozilla/dom/BindingDeclarations.h"

    26 class nsGlobalWindow;

    27 class nsIPrincipal;

    28 class nsScriptNameSpaceManager;

    29 class nsIGlobalObject;

    30 class nsIMemoryReporterCallback;

    32 #ifndef BAD_TLS_INDEX

    33 #define BAD_TLS_INDEX ((uint32_t) -1)

    34 #endif

    36 namespace xpc {

    38 class Scriptability {

    39 public:

    40     Scriptability(JSCompartment *c);

    41     bool Allowed();

    42     bool IsImmuneToScriptPolicy();

    44     void Block();

    45     void Unblock();

    46     void SetDocShellAllowsScript(bool aAllowed);

    48     static Scriptability& Get(JSObject *aScope);

    50 private:

    51     // Whenever a consumer wishes to prevent script from running on a global,

    52     // it increments this value with a call to Block(). When it wishes to

    53     // re-enable it (if ever), it decrements this value with a call to Unblock().

    54     // Script may not run if this value is non-zero.

    55     uint32_t mScriptBlocks;

    57     // Whether the docshell allows javascript in this scope. If this scope

    58     // doesn't have a docshell, this value is always true.

    59     bool mDocShellAllowsScript;

    61     // Whether this scope is immune to user-defined or addon-defined script

    62     // policy.

    63     bool mImmuneToScriptPolicy;

    65     // Whether the new-style domain policy when this compartment was created

    66     // forbids script execution.

    67     bool mScriptBlockedByPolicy;

    68 };

    70 JSObject *

    71 TransplantObject(JSContext *cx, JS::HandleObject origobj, JS::HandleObject target);

    73 bool IsXBLScope(JSCompartment *compartment);

    74 bool IsInXBLScope(JSObject *obj);

    76 // Return a raw XBL scope object corresponding to contentScope, which must

    77 // be an object whose global is a DOM window.

    78 //

    79 // The return value is not wrapped into cx->compartment, so be sure to enter

    80 // its compartment before doing anything meaningful.

    81 //

    82 // Also note that XBL scopes are lazily created, so the return-value should be

    83 // null-checked unless the caller can ensure that the scope must already

    84 // exist.

    85 //

    86 // This function asserts if |contentScope| is itself in an XBL scope to catch

    87 // sloppy consumers. Conversely, GetXBLScopeOrGlobal will handle objects that

    88 // are in XBL scope (by just returning the global).

    89 JSObject *

    90 GetXBLScope(JSContext *cx, JSObject *contentScope);

    92 inline JSObject *

    93 GetXBLScopeOrGlobal(JSContext *cx, JSObject *obj) {

    94     if (IsInXBLScope(obj))

    95         return js::GetGlobalForObjectCrossCompartment(obj);

    96     return GetXBLScope(cx, obj);

    97 }

    99 // Returns whether XBL scopes have been explicitly disabled for code running

   100 // in this compartment. See the comment around mAllowXBLScope.

   101 bool

   102 AllowXBLScope(JSCompartment *c);

   104 // Returns whether we will use an XBL scope for this compartment. This is

   105 // semantically equivalent to comparing global != GetXBLScope(global), but it

   106 // does not have the side-effect of eagerly creating the XBL scope if it does

   107 // not already exist.

   108 bool

   109 UseXBLScope(JSCompartment *c);

   111 bool

   112 IsSandboxPrototypeProxy(JSObject *obj);

   114 bool

   115 IsReflector(JSObject *obj);

   117 bool

   118 IsXrayWrapper(JSObject *obj);

   120 // If this function was created for a given XrayWrapper, returns the global of

   121 // the Xrayed object. Otherwise, returns the global of the function.

   122 //

   123 // To emphasize the obvious: the return value here is not necessarily same-

   124 // compartment with the argument.

   125 JSObject *

   126 XrayAwareCalleeGlobal(JSObject *fun);

   128 void

   129 TraceXPCGlobal(JSTracer *trc, JSObject *obj);

   131 } /* namespace xpc */

   133 namespace JS {

   135 struct RuntimeStats;

   137 }

   139 #define XPCONNECT_GLOBAL_FLAGS_WITH_EXTRA_SLOTS(n)                            \

   140     JSCLASS_DOM_GLOBAL | JSCLASS_HAS_PRIVATE |                                \

   141     JSCLASS_PRIVATE_IS_NSISUPPORTS | JSCLASS_IMPLEMENTS_BARRIERS |            \

   142     JSCLASS_GLOBAL_FLAGS_WITH_SLOTS(DOM_GLOBAL_SLOTS + n)

   144 #define XPCONNECT_GLOBAL_EXTRA_SLOT_OFFSET (JSCLASS_GLOBAL_SLOT_COUNT + DOM_GLOBAL_SLOTS)

   146 #define XPCONNECT_GLOBAL_FLAGS XPCONNECT_GLOBAL_FLAGS_WITH_EXTRA_SLOTS(0)

   148 inline JSObject*

   149 xpc_FastGetCachedWrapper(JSContext *cx, nsWrapperCache *cache, JS::MutableHandleValue vp)

   150 {

   151     if (cache) {

   152         JSObject* wrapper = cache->GetWrapper();

   153         if (wrapper &&

   154             js::GetObjectCompartment(wrapper) == js::GetContextCompartment(cx))

   155         {

   156             vp.setObject(*wrapper);

   157             return wrapper;

   158         }

   159     }

   161     return nullptr;

   162 }

   164 // The JS GC marks objects gray that are held alive directly or

   165 // indirectly by an XPConnect root. The cycle collector explores only

   166 // this subset of the JS heap.

   167 inline bool

   168 xpc_IsGrayGCThing(void *thing)

   169 {

   170     return JS::GCThingIsMarkedGray(thing);

   171 }

   173 // The cycle collector only cares about some kinds of GCthings that are

   174 // reachable from an XPConnect root. Implemented in nsXPConnect.cpp.

   175 extern bool

   176 xpc_GCThingIsGrayCCThing(void *thing);

   178 inline JSScript *

   179 xpc_UnmarkGrayScript(JSScript *script)

   180 {

   181     if (script)

   182         JS::ExposeGCThingToActiveJS(script, JSTRACE_SCRIPT);

   184     return script;

   185 }

   187 // If aVariant is an XPCVariant, this marks the object to be in aGeneration.

   188 // This also unmarks the gray JSObject.

   189 extern void

   190 xpc_MarkInCCGeneration(nsISupports* aVariant, uint32_t aGeneration);

   192 // If aWrappedJS is a JS wrapper, unmark its JSObject.

   193 extern void

   194 xpc_TryUnmarkWrappedGrayObject(nsISupports* aWrappedJS);

   196 extern void

   197 xpc_UnmarkSkippableJSHolders();

   199 // No JS can be on the stack when this is called. Probably only useful from

   200 // xpcshell.

   201 void

   202 xpc_ActivateDebugMode();

   204 // readable string conversions, static methods and members only

   205 class XPCStringConvert

   206 {

   207     // One-slot cache, because it turns out it's common for web pages to

   208     // get the same string a few times in a row.  We get about a 40% cache

   209     // hit rate on this cache last it was measured.  We'd get about 70%

   210     // hit rate with a hashtable with removal on finalization, but that

   211     // would take a lot more machinery.

   212     struct ZoneStringCache

   213     {

   214         nsStringBuffer* mBuffer;

   215         JSString* mString;

   216     };

   218 public:

   220     // If the string shares the readable's buffer, that buffer will

   221     // get assigned to *sharedBuffer.  Otherwise null will be

   222     // assigned.

   223     static bool ReadableToJSVal(JSContext *cx, const nsAString &readable,

   224                                 nsStringBuffer** sharedBuffer,

   225                                 JS::MutableHandleValue vp);

   227     // Convert the given stringbuffer/length pair to a jsval

   228     static MOZ_ALWAYS_INLINE bool

   229     StringBufferToJSVal(JSContext* cx, nsStringBuffer* buf, uint32_t length,

   230                         JS::MutableHandleValue rval, bool* sharedBuffer)

   231     {

   232         JS::Zone *zone = js::GetContextZone(cx);

   233         ZoneStringCache *cache = static_cast<ZoneStringCache*>(JS_GetZoneUserData(zone));

   234         if (cache && buf == cache->mBuffer) {

   235             MOZ_ASSERT(JS::GetGCThingZone(cache->mString) == zone);

   236             JS::MarkStringAsLive(zone, cache->mString);

   237             rval.setString(cache->mString);

   238             *sharedBuffer = false;

   239             return true;

   240         }

   242         JSString *str = JS_NewExternalString(cx,

   243                                              static_cast<jschar*>(buf->Data()),

   244                                              length, &sDOMStringFinalizer);

   245         if (!str) {

   246             return false;

   247         }

   248         rval.setString(str);

   249         if (!cache) {

   250             cache = new ZoneStringCache();

   251             JS_SetZoneUserData(zone, cache);

   252         }

   253         cache->mBuffer = buf;

   254         cache->mString = str;

   255         *sharedBuffer = true;

   256         return true;

   257     }

   259     static void FreeZoneCache(JS::Zone *zone);

   260     static void ClearZoneCache(JS::Zone *zone);

   262     static MOZ_ALWAYS_INLINE bool IsLiteral(JSString *str)

   263     {

   264         return JS_IsExternalString(str) &&

   265                JS_GetExternalStringFinalizer(str) == &sLiteralFinalizer;

   266     }

   268     static MOZ_ALWAYS_INLINE bool IsDOMString(JSString *str)

   269     {

   270         return JS_IsExternalString(str) &&

   271                JS_GetExternalStringFinalizer(str) == &sDOMStringFinalizer;

   272     }

   274 private:

   275     static const JSStringFinalizer sLiteralFinalizer, sDOMStringFinalizer;

   277     static void FinalizeLiteral(const JSStringFinalizer *fin, jschar *chars);

   279     static void FinalizeDOMString(const JSStringFinalizer *fin, jschar *chars);

   281     XPCStringConvert();         // not implemented

   282 };

   284 namespace xpc {

   286 // If these functions return false, then an exception will be set on cx.

   287 bool Base64Encode(JSContext *cx, JS::HandleValue val, JS::MutableHandleValue out);

   288 bool Base64Decode(JSContext *cx, JS::HandleValue val, JS::MutableHandleValue out);

   290 /**

   291  * Convert an nsString to jsval, returning true on success.

   292  * Note, the ownership of the string buffer may be moved from str to rval.

   293  * If that happens, str will point to an empty string after this call.

   294  */

   295 bool NonVoidStringToJsval(JSContext *cx, nsAString &str, JS::MutableHandleValue rval);

   296 inline bool StringToJsval(JSContext *cx, nsAString &str, JS::MutableHandleValue rval)

   297 {

   298     // From the T_DOMSTRING case in XPCConvert::NativeData2JS.

   299     if (str.IsVoid()) {

   300         rval.setNull();

   301         return true;

   302     }

   303     return NonVoidStringToJsval(cx, str, rval);

   304 }

   306 inline bool

   307 NonVoidStringToJsval(JSContext* cx, const nsAString& str, JS::MutableHandleValue rval)

   308 {

   309     nsString mutableCopy(str);

   310     return NonVoidStringToJsval(cx, mutableCopy, rval);

   311 }

   313 inline bool

   314 StringToJsval(JSContext* cx, const nsAString& str, JS::MutableHandleValue rval)

   315 {

   316     nsString mutableCopy(str);

   317     return StringToJsval(cx, mutableCopy, rval);

   318 }

   320 /**

   321  * As above, but for mozilla::dom::DOMString.

   322  */

   323 MOZ_ALWAYS_INLINE

   324 bool NonVoidStringToJsval(JSContext* cx, mozilla::dom::DOMString& str,

   325                           JS::MutableHandleValue rval)

   326 {

   327     if (!str.HasStringBuffer()) {

   328         // It's an actual XPCOM string

   329         return NonVoidStringToJsval(cx, str.AsAString(), rval);

   330     }

   332     uint32_t length = str.StringBufferLength();

   333     if (length == 0) {

   334         rval.set(JS_GetEmptyStringValue(cx));

   335         return true;

   336     }

   338     nsStringBuffer* buf = str.StringBuffer();

   339     bool shared;

   340     if (!XPCStringConvert::StringBufferToJSVal(cx, buf, length, rval,

   341                                                &shared)) {

   342         return false;

   343     }

   344     if (shared) {

   345         // JS now needs to hold a reference to the buffer

   346         buf->AddRef();

   347     }

   348     return true;

   349 }

   351 MOZ_ALWAYS_INLINE

   352 bool StringToJsval(JSContext* cx, mozilla::dom::DOMString& str,

   353                    JS::MutableHandleValue rval)

   354 {

   355     if (str.IsNull()) {

   356         rval.setNull();

   357         return true;

   358     }

   359     return NonVoidStringToJsval(cx, str, rval);

   360 }

   362 nsIPrincipal *GetCompartmentPrincipal(JSCompartment *compartment);

   364 void SetLocationForGlobal(JSObject *global, const nsACString& location);

   365 void SetLocationForGlobal(JSObject *global, nsIURI *locationURI);

   367 // ReportJSRuntimeExplicitTreeStats will expect this in the |extra| member

   368 // of JS::ZoneStats.

   369 class ZoneStatsExtras {

   370 public:

   371     ZoneStatsExtras()

   372     {}

   374     nsAutoCString pathPrefix;

   376 private:

   377     ZoneStatsExtras(const ZoneStatsExtras &other) MOZ_DELETE;

   378     ZoneStatsExtras& operator=(const ZoneStatsExtras &other) MOZ_DELETE;

   379 };

   381 // ReportJSRuntimeExplicitTreeStats will expect this in the |extra| member

   382 // of JS::CompartmentStats.

   383 class CompartmentStatsExtras {

   384 public:

   385     CompartmentStatsExtras()

   386     {}

   388     nsAutoCString jsPathPrefix;

   389     nsAutoCString domPathPrefix;

   390     nsCOMPtr<nsIURI> location;

   392 private:

   393     CompartmentStatsExtras(const CompartmentStatsExtras &other) MOZ_DELETE;

   394     CompartmentStatsExtras& operator=(const CompartmentStatsExtras &other) MOZ_DELETE;

   395 };

   397 // This reports all the stats in |rtStats| that belong in the "explicit" tree,

   398 // (which isn't all of them).

   399 // @see ZoneStatsExtras

   400 // @see CompartmentStatsExtras

   401 nsresult

   402 ReportJSRuntimeExplicitTreeStats(const JS::RuntimeStats &rtStats,

   403                                  const nsACString &rtPath,

   404                                  nsIMemoryReporterCallback *cb,

   405                                  nsISupports *closure, size_t *rtTotal = nullptr);

   407 /**

   408  * Throws an exception on cx and returns false.

   409  */

   410 bool

   411 Throw(JSContext *cx, nsresult rv);

   413 /**

   414  * Every global should hold a native that implements the nsIGlobalObject interface.

   415  */

   416 nsIGlobalObject *

   417 GetNativeForGlobal(JSObject *global);

   419 /**

   420  * In some cases a native object does not really belong to any compartment (XBL,

   421  * document created from by XHR of a worker, etc.). But when for some reason we

   422  * have to wrap these natives (because of an event for example) instead of just

   423  * wrapping them into some random compartment we find on the context stack (like

   424  * we did previously) a default compartment is used. This function returns that

   425  * compartment's global. It is a singleton on the runtime.

   426  * If you find yourself wanting to use this compartment, you're probably doing

   427  * something wrong. Callers MUST consult with the XPConnect module owner before

   428  * using this compartment. If you don't, bholley will hunt you down.

   429  */

   430 JSObject *

   431 GetJunkScope();

   433 /**

   434  * Returns the native global of the junk scope. See comment of GetJunkScope

   435  * about the conditions of using it.

   436  */

   437 nsIGlobalObject *

   438 GetJunkScopeGlobal();

   440 /**

   441  * Shared compilation scope for XUL prototype documents and XBL

   442  * precompilation. This compartment has a null principal. No code may run, and

   443  * it is invisible to the debugger.

   444  */

   445 JSObject *

   446 GetCompilationScope();

   448 /**

   449  * If |aObj| is a window, returns the associated nsGlobalWindow.

   450  * Otherwise, returns null.

   451  */

   452 nsGlobalWindow*

   453 WindowOrNull(JSObject *aObj);

   455 /*

   456  * Returns the dummy global associated with the SafeJSContext. Callers MUST

   457  * consult with the XPConnect module owner before using this function.

   458  */

   459 JSObject *

   460 GetSafeJSContextGlobal();

   462 /**

   463  * If |aObj| has a window for a global, returns the associated nsGlobalWindow.

   464  * Otherwise, returns null.

   465  */

   466 nsGlobalWindow*

   467 WindowGlobalOrNull(JSObject *aObj);

   469 // Error reporter used when there is no associated DOM window on to which to

   470 // report errors and warnings.

   471 void

   472 SystemErrorReporter(JSContext *cx, const char *message, JSErrorReport *rep);

   474 void

   475 SimulateActivityCallback(bool aActive);

   477 void

   478 RecordAdoptedNode(JSCompartment *c);

   480 void

   481 RecordDonatedNode(JSCompartment *c);

   483 // This function may be used off-main-thread, in which case it is benignly

   484 // racey.

   485 bool

   486 ShouldDiscardSystemSource();

   488 } // namespace xpc

   490 namespace mozilla {

   491 namespace dom {

   493 typedef JSObject*

   494 (*DefineInterface)(JSContext *cx, JS::Handle<JSObject*> global,

   495                    JS::Handle<jsid> id, bool defineOnGlobal);

   497 typedef JSObject*

   498 (*ConstructNavigatorProperty)(JSContext *cx, JS::Handle<JSObject*> naviObj);

   500 // Check whether a constructor should be enabled for the given object.

   501 // Note that the object should NOT be an Xray, since Xrays will end up

   502 // defining constructors on the underlying object.

   503 // This is a typedef for the function type itself, not the function

   504 // pointer, so it's more obvious that pointers to a ConstructorEnabled

   505 // can be null.

   506 typedef bool

   507 (ConstructorEnabled)(JSContext* cx, JS::Handle<JSObject*> obj);

   509 void

   510 Register(nsScriptNameSpaceManager* aNameSpaceManager);

   512 /**

   513  * A test for whether WebIDL methods that should only be visible to

   514  * chrome or XBL scopes should be exposed.

   515  */

   516 bool IsChromeOrXBL(JSContext* cx, JSObject* /* unused */);

   518 } // namespace dom

   519 } // namespace mozilla

   521 #endif

The Tor Browser / file revision

js/xpconnect/src/xpcpublic.h@a63d609f5ebe

js/xpconnect/src/xpcpublic.h