The Tor Browser: js/xpconnect/src/XPCQuickStubs.h@a63d609f5ebe (annotated)

js/xpconnect/src/XPCQuickStubs.h@a63d609f5ebe (annotated)

js/xpconnect/src/XPCQuickStubs.h

Thu, 15 Jan 2015 15:55:04 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:55:04 +0100
branch: TOR_BUG_9701
changeset 9: a63d609f5ebe
permissions: -rw-r--r--

Back out 97036ab72558 which inappropriately compared turds to third parties.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* vim: set ts=8 sts=4 et sw=4 tw=99: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef xpcquickstubs_h___
 #define xpcquickstubs_h___
 #include "XPCForwards.h"
 class qsObjectHelper;
 namespace mozilla {
 namespace dom {
 class NativePropertiesHolder;
 }
 }
 /* XPCQuickStubs.h - Support functions used only by quick stubs. */
 class XPCCallContext;
 #define XPC_QS_NULL_INDEX  ((uint16_t) -1)
 struct xpc_qsPropertySpec {
     uint16_t name_index;
     JSNative getter;
     JSNative setter;
 };
 struct xpc_qsFunctionSpec {
     uint16_t name_index;
     uint16_t arity;
     JSNative native;
 };
 /** A table mapping interfaces to quick stubs. */
 struct xpc_qsHashEntry {
     nsID iid;
     uint16_t prop_index;
     uint16_t n_props;
     uint16_t func_index;
     uint16_t n_funcs;
     const mozilla::dom::NativePropertiesHolder* newBindingProperties;
     // These last two fields index to other entries in the same table.
     // XPC_QS_NULL_ENTRY indicates there are no more entries in the chain.
     uint16_t parentInterface;
     uint16_t chain;
 };
 bool
 xpc_qsDefineQuickStubs(JSContext *cx, JSObject *proto, unsigned extraFlags,
                        uint32_t ifacec, const nsIID **interfaces,
                        uint32_t tableSize, const xpc_qsHashEntry *table,
                        const xpc_qsPropertySpec *propspecs,
                        const xpc_qsFunctionSpec *funcspecs,
                        const char *stringTable);
 /** Raise an exception on @a cx and return false. */
 bool
 xpc_qsThrow(JSContext *cx, nsresult rv);
 /**
  * Fail after an XPCOM getter or setter returned rv.
  *
  * NOTE: Here @a obj must be the JSObject whose private data field points to an
  * XPCWrappedNative, not merely an object that has an XPCWrappedNative
  * somewhere along the prototype chain!  The same applies to @a obj in
  * xpc_qsThrowBadSetterValue and <code>vp[1]</code> in xpc_qsThrowMethodFailed
  * and xpc_qsThrowBadArg.
  *
  * This is one reason the UnwrapThis functions below have an out parameter that
  * receives the wrapper JSObject.  (The other reason is to help the caller keep
  * that JSObject GC-reachable.)
  */
 bool
 xpc_qsThrowGetterSetterFailed(JSContext *cx, nsresult rv,
                               JSObject *obj, jsid memberId);
 // And variants using strings and string tables
 bool
 xpc_qsThrowGetterSetterFailed(JSContext *cx, nsresult rv,
                               JSObject *obj, const char* memberName);
 bool
 xpc_qsThrowGetterSetterFailed(JSContext *cx, nsresult rv,
                               JSObject *obj, uint16_t memberIndex);
 /**
  * Fail after an XPCOM method returned rv.
  *
  * See NOTE at xpc_qsThrowGetterSetterFailed.
  */
 bool
 xpc_qsThrowMethodFailed(JSContext *cx, nsresult rv, jsval *vp);
 /**
  * Fail after converting a method argument fails.
  *
  * See NOTE at xpc_qsThrowGetterSetterFailed.
  */
 void
 xpc_qsThrowBadArg(JSContext *cx, nsresult rv, jsval *vp, unsigned paramnum);
 void
 xpc_qsThrowBadArgWithCcx(XPCCallContext &ccx, nsresult rv, unsigned paramnum);
 void
 xpc_qsThrowBadArgWithDetails(JSContext *cx, nsresult rv, unsigned paramnum,
                              const char *ifaceName, const char *memberName);
 /**
  * Fail after converting a setter argument fails.
  *
  * See NOTE at xpc_qsThrowGetterSetterFailed.
  */
 void
 xpc_qsThrowBadSetterValue(JSContext *cx, nsresult rv, JSObject *obj,
                           jsid propId);
 // And variants using strings and string tables
 void
 xpc_qsThrowBadSetterValue(JSContext *cx, nsresult rv, JSObject *obj,
                           const char* propName);
 void
 xpc_qsThrowBadSetterValue(JSContext *cx, nsresult rv, JSObject *obj,
                           uint16_t name_index);
 bool
 xpc_qsGetterOnlyPropertyStub(JSContext *cx, JS::HandleObject obj, JS::HandleId id,
                              bool strict, JS::MutableHandleValue vp);
 bool
 xpc_qsGetterOnlyNativeStub(JSContext *cx, unsigned argc, jsval *vp);
 /* Functions for converting values between COM and JS. */
 inline bool
 xpc_qsInt64ToJsval(JSContext *cx, int64_t i, JS::MutableHandleValue rv)
 {
     rv.setNumber(static_cast<double>(i));
     return true;
 }
 inline bool
 xpc_qsUint64ToJsval(JSContext *cx, uint64_t u, JS::MutableHandleValue rv)
 {
     rv.setNumber(static_cast<double>(u));
     return true;
 }
 /* Classes for converting jsvals to string types. */
 template <class S, class T>
 class xpc_qsBasicString
 {
 public:
     typedef S interface_type;
     typedef T implementation_type;
     ~xpc_qsBasicString()
     {
         if (mValid)
             Ptr()->~implementation_type();
     }
     bool IsValid() const { return mValid; }
     implementation_type *Ptr()
     {
         MOZ_ASSERT(mValid);
         return reinterpret_cast<implementation_type *>(mBuf);
     }
     const implementation_type *Ptr() const
     {
         MOZ_ASSERT(mValid);
         return reinterpret_cast<const implementation_type *>(mBuf);
     }
     operator interface_type &()
     {
         MOZ_ASSERT(mValid);
         return *Ptr();
     }
     operator const interface_type &() const
     {
         MOZ_ASSERT(mValid);
         return *Ptr();
     }
     /* Enum that defines how JS |null| and |undefined| should be treated.  See
      * the WebIDL specification.  eStringify means convert to the string "null"
      * or "undefined" respectively, via the standard JS ToString() operation;
      * eEmpty means convert to the string ""; eNull means convert to an empty
      * string with the void bit set.
      *
      * Per webidl the default behavior of an unannotated interface is
      * eStringify, but our de-facto behavior has been eNull for |null| and
      * eStringify for |undefined|, so leaving it that way for now.  If we ever
      * get to a point where we go through and annotate our interfaces as
      * needed, we can change that.
      */
     enum StringificationBehavior {
         eStringify,
         eEmpty,
         eNull,
         eDefaultNullBehavior = eNull,
         eDefaultUndefinedBehavior = eStringify
     };
 protected:
     /*
      * Neither field is initialized; that is left to the derived class
      * constructor. However, the destructor destroys the string object
      * stored in mBuf, if mValid is true.
      */
     void *mBuf[JS_HOWMANY(sizeof(implementation_type), sizeof(void *))];
     bool mValid;
     /*
      * If null is returned, then we either failed or fully initialized
      * |this|; in either case the caller should return immediately
      * without doing anything else. Otherwise, the JSString* created
      * from |v| will be returned.  It'll be rooted, as needed, in
      * *pval.  nullBehavior and undefinedBehavior control what happens
      * when |v| is JSVAL_IS_NULL and JSVAL_IS_VOID respectively.
      */
     template<class traits>
     JSString* InitOrStringify(JSContext* cx, JS::HandleValue v,
                               JS::MutableHandleValue pval,
                               bool notpassed,
                               StringificationBehavior nullBehavior,
                               StringificationBehavior undefinedBehavior) {
         JSString *s;
         if (JSVAL_IS_STRING(v)) {
             s = JSVAL_TO_STRING(v);
         } else {
             StringificationBehavior behavior = eStringify;
             if (JSVAL_IS_NULL(v)) {
                 behavior = nullBehavior;
             } else if (JSVAL_IS_VOID(v)) {
                 behavior = undefinedBehavior;
             }
             // If pval is null, that means the argument was optional and
             // not passed; turn those into void strings if they're
             // supposed to be stringified.
             if (behavior != eStringify || notpassed) {
                 // Here behavior == eStringify implies notpassed, so both eNull and
                 // eStringify should end up with void strings.
                 (new(mBuf) implementation_type(traits::sEmptyBuffer, uint32_t(0)))->
                     SetIsVoid(behavior != eEmpty);
                 mValid = true;
                 return nullptr;
             }
             s = JS::ToString(cx, v);
             if (!s) {
                 mValid = false;
                 return nullptr;
             }
             pval.setString(s);  // Root the new string.
         }
         return s;
     }
 };
 /**
  * Class for converting a jsval to DOMString.
  *
  *     xpc_qsDOMString arg0(cx, &argv[0]);
  *     if (!arg0.IsValid())
  *         return false;
  *
  * The second argument to the constructor is an in-out parameter. It must
  * point to a rooted jsval, such as a JSNative argument or return value slot.
  * The value in the jsval on entry is converted to a string. The constructor
  * may overwrite that jsval with a string value, to protect the characters of
  * the string from garbage collection. The caller must leave the jsval alone
  * for the lifetime of the xpc_qsDOMString.
  */
 class xpc_qsDOMString : public xpc_qsBasicString<nsAString, nsDependentString>
 {
 public:
     xpc_qsDOMString(JSContext *cx, JS::HandleValue v,
                     JS::MutableHandleValue pval, bool notpassed,
                     StringificationBehavior nullBehavior,
                     StringificationBehavior undefinedBehavior);
 };
 /**
  * The same as xpc_qsDOMString, but with slightly different conversion behavior,
  * corresponding to the [astring] magic XPIDL annotation rather than [domstring].
  */
 class xpc_qsAString : public xpc_qsDOMString
 {
 public:
     xpc_qsAString(JSContext *cx, JS::HandleValue v,
                   JS::MutableHandleValue pval, bool notpassed)
         : xpc_qsDOMString(cx, v, pval, notpassed, eNull, eNull)
     {}
 };
 /**
  * Like xpc_qsDOMString and xpc_qsAString, but for XPIDL native types annotated
  * with [cstring] rather than [domstring] or [astring].
  */
 class xpc_qsACString : public xpc_qsBasicString<nsACString, nsCString>
 {
 public:
     xpc_qsACString(JSContext *cx, JS::HandleValue v,
                    JS::MutableHandleValue pval, bool notpassed,
                    StringificationBehavior nullBehavior = eNull,
                    StringificationBehavior undefinedBehavior = eNull);
 };
 /**
  * And similar for AUTF8String.
  */
 class xpc_qsAUTF8String :
   public xpc_qsBasicString<nsACString, NS_ConvertUTF16toUTF8>
 {
 public:
   xpc_qsAUTF8String(JSContext* cx, JS::HandleValue v,
                     JS::MutableHandleValue pval, bool notpassed);
 };
 struct xpc_qsSelfRef
 {
     xpc_qsSelfRef() : ptr(nullptr) {}
     explicit xpc_qsSelfRef(nsISupports *p) : ptr(p) {}
     ~xpc_qsSelfRef() { NS_IF_RELEASE(ptr); }
     nsISupports* ptr;
 };
 /**
  * Convert a jsval to char*, returning true on success.
  *
  * @param cx
  *     A context.
  * @param v
  *     A value to convert.
  * @param bytes
  *     Out. On success it receives the converted string unless v is null or
  *     undefinedin which case bytes->ptr() remains null.
  */
 bool
 xpc_qsJsvalToCharStr(JSContext *cx, jsval v, JSAutoByteString *bytes);
 bool
 xpc_qsJsvalToWcharStr(JSContext *cx, jsval v, JS::MutableHandleValue pval, const char16_t **pstr);
 nsresult
 getWrapper(JSContext *cx,
            JSObject *obj,
            XPCWrappedNative **wrapper,
            JSObject **cur,
            XPCWrappedNativeTearOff **tearoff);
 nsresult
 castNative(JSContext *cx,
            XPCWrappedNative *wrapper,
            JSObject *cur,
            XPCWrappedNativeTearOff *tearoff,
            const nsIID &iid,
            void **ppThis,
            nsISupports **ppThisRef,
            JS::MutableHandleValue vp);
 /**
  * Search @a obj and its prototype chain for an XPCOM object that implements
  * the interface T.
  *
  * If an object implementing T is found, store a reference to the wrapper
  * JSObject in @a *pThisVal, store a pointer to the T in @a *ppThis, and return
  * true. Otherwise, raise an exception on @a cx and return false.
  *
  * @a *pThisRef receives the same pointer as *ppThis if the T was AddRefed.
  * Otherwise it receives null (even on error).
  *
  * This supports split objects and XPConnect tear-offs and it sees through
  * XOWs, XPCNativeWrappers, and SafeJSObjectWrappers.
  *
  * Requires a request on @a cx.
  */
 template <class T>
 inline bool
 xpc_qsUnwrapThis(JSContext *cx,
                  JS::HandleObject obj,
                  T **ppThis,
                  nsISupports **pThisRef,
                  JS::MutableHandleValue pThisVal,
                  bool failureFatal = true)
 {
     XPCWrappedNative *wrapper;
     XPCWrappedNativeTearOff *tearoff;
     JS::RootedObject current(cx);
     nsresult rv = getWrapper(cx, obj, &wrapper, current.address(), &tearoff);
     if (NS_SUCCEEDED(rv))
         rv = castNative(cx, wrapper, current, tearoff, NS_GET_TEMPLATE_IID(T),
                         reinterpret_cast<void **>(ppThis), pThisRef, pThisVal);
     if (failureFatal)
         return NS_SUCCEEDED(rv) || xpc_qsThrow(cx, rv);
     if (NS_FAILED(rv))
         *ppThis = nullptr;
     return true;
 }
 nsISupports*
 castNativeFromWrapper(JSContext *cx,
                       JSObject *obj,
                       uint32_t interfaceBit,
                       uint32_t protoID,
                       int32_t protoDepth,
                       nsISupports **pRef,
                       JS::MutableHandleValue pVal,
                       nsresult *rv);
 bool
 xpc_qsUnwrapThisFromCcxImpl(XPCCallContext &ccx,
                             const nsIID &iid,
                             void **ppThis,
                             nsISupports **pThisRef,
                             JS::MutableHandleValue vp);
 /**
  * Alternate implementation of xpc_qsUnwrapThis using information already
  * present in the given XPCCallContext.
  */
 template <class T>
 inline bool
 xpc_qsUnwrapThisFromCcx(XPCCallContext &ccx,
                         T **ppThis,
                         nsISupports **pThisRef,
                         JS::MutableHandleValue pThisVal)
 {
     return xpc_qsUnwrapThisFromCcxImpl(ccx,
                                        NS_GET_TEMPLATE_IID(T),
                                        reinterpret_cast<void **>(ppThis),
                                        pThisRef,
                                        pThisVal);
 }
 MOZ_ALWAYS_INLINE JSObject*
 xpc_qsUnwrapObj(jsval v, nsISupports **ppArgRef, nsresult *rv)
 {
     *rv = NS_OK;
     if (v.isObject()) {
         return &v.toObject();
     }
     if (!v.isNullOrUndefined()) {
         *rv = ((v.isInt32() && v.toInt32() == 0)
                ? NS_ERROR_XPC_BAD_CONVERT_JS_ZERO_ISNOT_NULL
                : NS_ERROR_XPC_BAD_CONVERT_JS);
     }
     *ppArgRef = nullptr;
     return nullptr;
 }
 nsresult
 xpc_qsUnwrapArgImpl(JSContext *cx, JS::HandleValue v, const nsIID &iid, void **ppArg,
                     nsISupports **ppArgRef, JS::MutableHandleValue vp);
 /** Convert a jsval to an XPCOM pointer. */
 template <class Interface, class StrongRefType>
 inline nsresult
 xpc_qsUnwrapArg(JSContext *cx, JS::HandleValue v, Interface **ppArg,
                 StrongRefType **ppArgRef, JS::MutableHandleValue vp)
 {
     nsISupports* argRef = *ppArgRef;
     nsresult rv = xpc_qsUnwrapArgImpl(cx, v, NS_GET_TEMPLATE_IID(Interface),
                                       reinterpret_cast<void **>(ppArg), &argRef,
                                       vp);
     *ppArgRef = static_cast<StrongRefType*>(argRef);
     return rv;
 }
 MOZ_ALWAYS_INLINE nsISupports*
 castNativeArgFromWrapper(JSContext *cx,
                          jsval v,
                          uint32_t bit,
                          uint32_t protoID,
                          int32_t protoDepth,
                          nsISupports **pArgRef,
                          JS::MutableHandleValue vp,
                          nsresult *rv)
 {
     JSObject *src = xpc_qsUnwrapObj(v, pArgRef, rv);
     if (!src)
         return nullptr;
     return castNativeFromWrapper(cx, src, bit, protoID, protoDepth, pArgRef, vp, rv);
 }
 inline nsWrapperCache*
 xpc_qsGetWrapperCache(nsWrapperCache *cache)
 {
     return cache;
 }
 inline nsWrapperCache*
 xpc_qsGetWrapperCache(void *p)
 {
     return nullptr;
 }
 /** Convert an XPCOM pointer to jsval. Return true on success.
  * aIdentity is a performance optimization. Set it to true,
  * only if p is the identity pointer.
  */
 bool
 xpc_qsXPCOMObjectToJsval(JSContext *aCx,
                          qsObjectHelper &aHelper,
                          const nsIID *iid,
                          XPCNativeInterface **iface,
                          JS::MutableHandleValue rval);
 /**
  * Convert a variant to jsval. Return true on success.
  */
 bool
 xpc_qsVariantToJsval(JSContext *cx,
                      nsIVariant *p,
                      JS::MutableHandleValue rval);
 #ifdef DEBUG
 void
 xpc_qsAssertContextOK(JSContext *cx);
 inline bool
 xpc_qsSameResult(nsISupports *result1, nsISupports *result2)
 {
     return SameCOMIdentity(result1, result2);
 }
 inline bool
 xpc_qsSameResult(const nsString &result1, const nsString &result2)
 {
     return result1.Equals(result2);
 }
 inline bool
 xpc_qsSameResult(int32_t result1, int32_t result2)
 {
     return result1 == result2;
 }
 #define XPC_QS_ASSERT_CONTEXT_OK(cx) xpc_qsAssertContextOK(cx)
 #else
 #define XPC_QS_ASSERT_CONTEXT_OK(cx) ((void) 0)
 #endif
 // Apply |op| to |obj|, |id|, and |vp|. If |op| is a setter, treat the assignment as lenient.
 template<typename Op>
 inline bool ApplyPropertyOp(JSContext *cx, Op op, JS::HandleObject obj, JS::HandleId id,
                               JS::MutableHandleValue vp);
 template<>
 inline bool
 ApplyPropertyOp<JSPropertyOp>(JSContext *cx, JSPropertyOp op, JS::HandleObject obj, JS::HandleId id,
                               JS::MutableHandleValue vp)
 {
     return op(cx, obj, id, vp);
 }
 template<>
 inline bool
 ApplyPropertyOp<JSStrictPropertyOp>(JSContext *cx, JSStrictPropertyOp op, JS::HandleObject obj,
                                     JS::HandleId id, JS::MutableHandleValue vp)
 {
     return op(cx, obj, id, true, vp);
 }
 template<typename Op>
 bool
 PropertyOpForwarder(JSContext *cx, unsigned argc, jsval *vp)
 {
     // Layout:
     //   this = our this
     //   property op to call = callee reserved slot 0
     //   name of the property = callee reserved slot 1
     JS::CallArgs args = CallArgsFromVp(argc, vp);
     JS::RootedObject callee(cx, &args.callee());
     JS::RootedObject obj(cx, JS_THIS_OBJECT(cx, vp));
     if (!obj)
         return false;
     JS::RootedValue v(cx, js::GetFunctionNativeReserved(callee, 0));
     JSObject *ptrobj = JSVAL_TO_OBJECT(v);
     Op *popp = static_cast<Op *>(JS_GetPrivate(ptrobj));
     v = js::GetFunctionNativeReserved(callee, 1);
     JS::RootedValue argval(cx, args.get(0));
     JS::RootedId id(cx);
     if (!JS_ValueToId(cx, v, &id))
         return false;
     args.rval().set(argval);
     return ApplyPropertyOp<Op>(cx, *popp, obj, id, args.rval());
 }
 extern const JSClass PointerHolderClass;
 template<typename Op>
 JSObject *
 GeneratePropertyOp(JSContext *cx, JS::HandleObject obj, JS::HandleId id, unsigned argc, Op pop)
 {
     // The JS engine provides two reserved slots on function objects for
     // XPConnect to use. Use them to stick the necessary info here.
     JSFunction *fun =
         js::NewFunctionByIdWithReserved(cx, PropertyOpForwarder<Op>, argc, 0, obj, id);
     if (!fun)
         return nullptr;
     JS::RootedObject funobj(cx, JS_GetFunctionObject(fun));
     // Unfortunately, we cannot guarantee that Op is aligned. Use a
     // second object to work around this.
     JSObject *ptrobj = JS_NewObject(cx, &PointerHolderClass, JS::NullPtr(), funobj);
     if (!ptrobj)
         return nullptr;
     Op *popp = new Op;
     if (!popp)
         return nullptr;
     *popp = pop;
     JS_SetPrivate(ptrobj, popp);
     js::SetFunctionNativeReserved(funobj, 0, OBJECT_TO_JSVAL(ptrobj));
     js::SetFunctionNativeReserved(funobj, 1, js::IdToValue(id));
     return funobj;
 }
 #endif /* xpcquickstubs_h___ */

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js/xpconnect/src/XPCQuickStubs.h@a63d609f5ebe (annotated)

js/xpconnect/src/XPCQuickStubs.h