1 files changed, 497 insertions, 0 deletions
diff --git a/js/src/jscntxtinlines.h b/js/src/jscntxtinlines.h
new file mode 100644
index 000000000..069f34d1d
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+++ b/js/src/jscntxtinlines.h
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+/* -*- 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 jscntxtinlines_h
+#define jscntxtinlines_h
+
+#include "jscntxt.h"
+#include "jscompartment.h"
+
+#include "jsiter.h"
+
+#include "builtin/Object.h"
+#include "jit/JitFrames.h"
+#include "vm/HelperThreads.h"
+#include "vm/Interpreter.h"
+#include "vm/ProxyObject.h"
+#include "vm/Symbol.h"
+
+namespace js {
+
+class CompartmentChecker
+{
+    JSCompartment* compartment;
+
+  public:
+    explicit CompartmentChecker(ExclusiveContext* cx)
+      : compartment(cx->compartment())
+    {
+    }
+
+    /*
+     * Set a breakpoint here (break js::CompartmentChecker::fail) to debug
+     * compartment mismatches.
+     */
+    static void fail(JSCompartment* c1, JSCompartment* c2) {
+        printf("*** Compartment mismatch %p vs. %p\n", (void*) c1, (void*) c2);
+        MOZ_CRASH();
+    }
+
+    static void fail(JS::Zone* z1, JS::Zone* z2) {
+        printf("*** Zone mismatch %p vs. %p\n", (void*) z1, (void*) z2);
+        MOZ_CRASH();
+    }
+
+    /* Note: should only be used when neither c1 nor c2 may be the atoms compartment. */
+    static void check(JSCompartment* c1, JSCompartment* c2) {
+        MOZ_ASSERT(!c1->runtimeFromAnyThread()->isAtomsCompartment(c1));
+        MOZ_ASSERT(!c2->runtimeFromAnyThread()->isAtomsCompartment(c2));
+        if (c1 != c2)
+            fail(c1, c2);
+    }
+
+    void check(JSCompartment* c) {
+        if (c && !compartment->runtimeFromAnyThread()->isAtomsCompartment(c)) {
+            if (!compartment)
+                compartment = c;
+            else if (c != compartment)
+                fail(compartment, c);
+        }
+    }
+
+    void checkZone(JS::Zone* z) {
+        if (compartment && z != compartment->zone())
+            fail(compartment->zone(), z);
+    }
+
+    void check(JSObject* obj) {
+        MOZ_ASSERT_IF(obj, !JS::ObjectIsMarkedGray(obj));
+        if (obj)
+            check(obj->compartment());
+    }
+
+    template<typename T>
+    void check(const Rooted<T>& rooted) {
+        check(rooted.get());
+    }
+
+    template<typename T>
+    void check(Handle<T> handle) {
+        check(handle.get());
+    }
+
+    void check(JSString* str) {
+        MOZ_ASSERT(!js::gc::detail::CellIsMarkedGray(str));
+        if (!str->isAtom())
+            checkZone(str->zone());
+    }
+
+    void check(const js::Value& v) {
+        if (v.isObject())
+            check(&v.toObject());
+        else if (v.isString())
+            check(v.toString());
+    }
+
+    void check(const ValueArray& arr) {
+        for (size_t i = 0; i < arr.length; i++)
+            check(arr.array[i]);
+    }
+
+    void check(const JSValueArray& arr) {
+        for (size_t i = 0; i < arr.length; i++)
+            check(arr.array[i]);
+    }
+
+    void check(const JS::HandleValueArray& arr) {
+        for (size_t i = 0; i < arr.length(); i++)
+            check(arr[i]);
+    }
+
+    void check(const CallArgs& args) {
+        for (Value* p = args.base(); p != args.end(); ++p)
+            check(*p);
+    }
+
+    void check(jsid id) {}
+
+    void check(JSScript* script) {
+        MOZ_ASSERT_IF(script, !JS::ScriptIsMarkedGray(script));
+        if (script)
+            check(script->compartment());
+    }
+
+    void check(InterpreterFrame* fp);
+    void check(AbstractFramePtr frame);
+    void check(SavedStacks* stacks);
+
+    void check(Handle<PropertyDescriptor> desc) {
+        check(desc.object());
+        if (desc.hasGetterObject())
+            check(desc.getterObject());
+        if (desc.hasSetterObject())
+            check(desc.setterObject());
+        check(desc.value());
+    }
+
+    void check(TypeSet::Type type) {
+        check(type.maybeCompartment());
+    }
+};
+
+/*
+ * Don't perform these checks when called from a finalizer. The checking
+ * depends on other objects not having been swept yet.
+ */
+#define START_ASSERT_SAME_COMPARTMENT()                                       \
+    if (cx->isJSContext() && cx->asJSContext()->runtime()->isHeapBusy())      \
+        return;                                                               \
+    CompartmentChecker c(cx)
+
+template <class T1> inline void
+releaseAssertSameCompartment(ExclusiveContext* cx, const T1& t1)
+{
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+}
+
+template <class T1> inline void
+assertSameCompartment(ExclusiveContext* cx, const T1& t1)
+{
+#ifdef JS_CRASH_DIAGNOSTICS
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+#endif
+}
+
+template <class T1> inline void
+assertSameCompartmentDebugOnly(ExclusiveContext* cx, const T1& t1)
+{
+#if defined(DEBUG) && defined(JS_CRASH_DIAGNOSTICS)
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+#endif
+}
+
+template <class T1, class T2> inline void
+assertSameCompartment(ExclusiveContext* cx, const T1& t1, const T2& t2)
+{
+#ifdef JS_CRASH_DIAGNOSTICS
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+    c.check(t2);
+#endif
+}
+
+template <class T1, class T2, class T3> inline void
+assertSameCompartment(ExclusiveContext* cx, const T1& t1, const T2& t2, const T3& t3)
+{
+#ifdef JS_CRASH_DIAGNOSTICS
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+    c.check(t2);
+    c.check(t3);
+#endif
+}
+
+template <class T1, class T2, class T3, class T4> inline void
+assertSameCompartment(ExclusiveContext* cx,
+                      const T1& t1, const T2& t2, const T3& t3, const T4& t4)
+{
+#ifdef JS_CRASH_DIAGNOSTICS
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+    c.check(t2);
+    c.check(t3);
+    c.check(t4);
+#endif
+}
+
+template <class T1, class T2, class T3, class T4, class T5> inline void
+assertSameCompartment(ExclusiveContext* cx,
+                      const T1& t1, const T2& t2, const T3& t3, const T4& t4, const T5& t5)
+{
+#ifdef JS_CRASH_DIAGNOSTICS
+    START_ASSERT_SAME_COMPARTMENT();
+    c.check(t1);
+    c.check(t2);
+    c.check(t3);
+    c.check(t4);
+    c.check(t5);
+#endif
+}
+
+#undef START_ASSERT_SAME_COMPARTMENT
+
+STATIC_PRECONDITION_ASSUME(ubound(args.argv_) >= argc)
+MOZ_ALWAYS_INLINE bool
+CallJSNative(JSContext* cx, Native native, const CallArgs& args)
+{
+    JS_CHECK_RECURSION(cx, return false);
+
+#ifdef DEBUG
+    bool alreadyThrowing = cx->isExceptionPending();
+#endif
+    assertSameCompartment(cx, args);
+    bool ok = native(cx, args.length(), args.base());
+    if (ok) {
+        assertSameCompartment(cx, args.rval());
+        MOZ_ASSERT_IF(!alreadyThrowing, !cx->isExceptionPending());
+    }
+    return ok;
+}
+
+STATIC_PRECONDITION_ASSUME(ubound(args.argv_) >= argc)
+MOZ_ALWAYS_INLINE bool
+CallNativeImpl(JSContext* cx, NativeImpl impl, const CallArgs& args)
+{
+#ifdef DEBUG
+    bool alreadyThrowing = cx->isExceptionPending();
+#endif
+    assertSameCompartment(cx, args);
+    bool ok = impl(cx, args);
+    if (ok) {
+        assertSameCompartment(cx, args.rval());
+        MOZ_ASSERT_IF(!alreadyThrowing, !cx->isExceptionPending());
+    }
+    return ok;
+}
+
+STATIC_PRECONDITION(ubound(args.argv_) >= argc)
+MOZ_ALWAYS_INLINE bool
+CallJSNativeConstructor(JSContext* cx, Native native, const CallArgs& args)
+{
+#ifdef DEBUG
+    RootedObject callee(cx, &args.callee());
+#endif
+
+    MOZ_ASSERT(args.thisv().isMagic());
+    if (!CallJSNative(cx, native, args))
+        return false;
+
+    /*
+     * Native constructors must return non-primitive values on success.
+     * Although it is legal, if a constructor returns the callee, there is a
+     * 99.9999% chance it is a bug. If any valid code actually wants the
+     * constructor to return the callee, the assertion can be removed or
+     * (another) conjunct can be added to the antecedent.
+     *
+     * Exceptions:
+     *
+     * - Proxies are exceptions to both rules: they can return primitives and
+     *   they allow content to return the callee.
+     *
+     * - CallOrConstructBoundFunction is an exception as well because we might
+     *   have used bind on a proxy function.
+     *
+     * - new Iterator(x) is user-hookable; it returns x.__iterator__() which
+     *   could be any object.
+     *
+     * - (new Object(Object)) returns the callee.
+     */
+    MOZ_ASSERT_IF(native != js::proxy_Construct &&
+                  native != js::IteratorConstructor &&
+                  (!callee->is<JSFunction>() || callee->as<JSFunction>().native() != obj_construct),
+                  args.rval().isObject() && callee != &args.rval().toObject());
+
+    return true;
+}
+
+MOZ_ALWAYS_INLINE bool
+CallJSGetterOp(JSContext* cx, GetterOp op, HandleObject obj, HandleId id,
+               MutableHandleValue vp)
+{
+    JS_CHECK_RECURSION(cx, return false);
+
+    assertSameCompartment(cx, obj, id, vp);
+    bool ok = op(cx, obj, id, vp);
+    if (ok)
+        assertSameCompartment(cx, vp);
+    return ok;
+}
+
+MOZ_ALWAYS_INLINE bool
+CallJSSetterOp(JSContext* cx, SetterOp op, HandleObject obj, HandleId id, MutableHandleValue vp,
+               ObjectOpResult& result)
+{
+    JS_CHECK_RECURSION(cx, return false);
+
+    assertSameCompartment(cx, obj, id, vp);
+    return op(cx, obj, id, vp, result);
+}
+
+inline bool
+CallJSAddPropertyOp(JSContext* cx, JSAddPropertyOp op, HandleObject obj, HandleId id,
+                    HandleValue v)
+{
+    JS_CHECK_RECURSION(cx, return false);
+
+    assertSameCompartment(cx, obj, id, v);
+    return op(cx, obj, id, v);
+}
+
+inline bool
+CallJSDeletePropertyOp(JSContext* cx, JSDeletePropertyOp op, HandleObject receiver, HandleId id,
+                       ObjectOpResult& result)
+{
+    JS_CHECK_RECURSION(cx, return false);
+
+    assertSameCompartment(cx, receiver, id);
+    if (op)
+        return op(cx, receiver, id, result);
+    return result.succeed();
+}
+
+inline uintptr_t
+GetNativeStackLimit(ExclusiveContext* cx)
+{
+    StackKind kind;
+    if (cx->isJSContext()) {
+        kind = cx->asJSContext()->runningWithTrustedPrincipals()
+                 ? StackForTrustedScript : StackForUntrustedScript;
+    } else {
+        // For other threads, we just use the trusted stack depth, since it's
+        // unlikely that we'll be mixing trusted and untrusted code together.
+        kind = StackForTrustedScript;
+    }
+    return cx->nativeStackLimit[kind];
+}
+
+inline LifoAlloc&
+ExclusiveContext::typeLifoAlloc()
+{
+    return zone()->types.typeLifoAlloc;
+}
+
+}  /* namespace js */
+
+inline void
+JSContext::setPendingException(const js::Value& v)
+{
+    // overRecursed_ is set after the fact by ReportOverRecursed.
+    this->overRecursed_ = false;
+    this->throwing = true;
+    this->unwrappedException_ = v;
+    // We don't use assertSameCompartment here to allow
+    // js::SetPendingExceptionCrossContext to work.
+    MOZ_ASSERT_IF(v.isObject(), v.toObject().compartment() == compartment());
+}
+
+inline bool
+JSContext::runningWithTrustedPrincipals() const
+{
+    return !compartment() || compartment()->principals() == trustedPrincipals();
+}
+
+inline void
+js::ExclusiveContext::enterCompartment(
+    JSCompartment* c,
+    const js::AutoLockForExclusiveAccess* maybeLock /* = nullptr */)
+{
+    enterCompartmentDepth_++;
+    c->enter();
+    setCompartment(c, maybeLock);
+}
+
+inline void
+js::ExclusiveContext::enterNullCompartment()
+{
+    enterCompartmentDepth_++;
+    setCompartment(nullptr);
+}
+
+inline void
+js::ExclusiveContext::leaveCompartment(
+    JSCompartment* oldCompartment,
+    const js::AutoLockForExclusiveAccess* maybeLock /* = nullptr */)
+{
+    MOZ_ASSERT(hasEnteredCompartment());
+    enterCompartmentDepth_--;
+
+    // Only call leave() after we've setCompartment()-ed away from the current
+    // compartment.
+    JSCompartment* startingCompartment = compartment_;
+    setCompartment(oldCompartment, maybeLock);
+    if (startingCompartment)
+        startingCompartment->leave();
+}
+
+inline void
+js::ExclusiveContext::setCompartment(JSCompartment* comp,
+                                     const AutoLockForExclusiveAccess* maybeLock /* = nullptr */)
+{
+    // ExclusiveContexts can only be in the atoms zone or in exclusive zones.
+    MOZ_ASSERT_IF(!isJSContext() && !runtime_->isAtomsCompartment(comp),
+                  comp->zone()->usedByExclusiveThread);
+
+    // Normal JSContexts cannot enter exclusive zones.
+    MOZ_ASSERT_IF(isJSContext() && comp,
+                  !comp->zone()->usedByExclusiveThread);
+
+    // Only one thread can be in the atoms compartment at a time.
+    MOZ_ASSERT_IF(runtime_->isAtomsCompartment(comp), maybeLock != nullptr);
+
+    // Make sure that the atoms compartment has its own zone.
+    MOZ_ASSERT_IF(comp && !runtime_->isAtomsCompartment(comp),
+                  !comp->zone()->isAtomsZone());
+
+    // Both the current and the new compartment should be properly marked as
+    // entered at this point.
+    MOZ_ASSERT_IF(compartment_, compartment_->hasBeenEntered());
+    MOZ_ASSERT_IF(comp, comp->hasBeenEntered());
+
+    compartment_ = comp;
+    zone_ = comp ? comp->zone() : nullptr;
+    arenas_ = zone_ ? &zone_->arenas : nullptr;
+}
+
+inline JSScript*
+JSContext::currentScript(jsbytecode** ppc,
+                         MaybeAllowCrossCompartment allowCrossCompartment) const
+{
+    if (ppc)
+        *ppc = nullptr;
+
+    js::Activation* act = activation();
+    while (act && act->isJit() && !act->asJit()->isActive())
+        act = act->prev();
+
+    if (!act)
+        return nullptr;
+
+    MOZ_ASSERT(act->cx() == this);
+
+    if (act->isJit()) {
+        JSScript* script = nullptr;
+        js::jit::GetPcScript(const_cast<JSContext*>(this), &script, ppc);
+        if (!allowCrossCompartment && script->compartment() != compartment()) {
+            if (ppc)
+                *ppc = nullptr;
+            return nullptr;
+        }
+        return script;
+    }
+
+    if (act->isWasm())
+        return nullptr;
+
+    MOZ_ASSERT(act->isInterpreter());
+
+    js::InterpreterFrame* fp = act->asInterpreter()->current();
+    MOZ_ASSERT(!fp->runningInJit());
+
+    JSScript* script = fp->script();
+    if (!allowCrossCompartment && script->compartment() != compartment())
+        return nullptr;
+
+    if (ppc) {
+        *ppc = act->asInterpreter()->regs().pc;
+        MOZ_ASSERT(script->containsPC(*ppc));
+    }
+    return script;
+}
+
+#endif /* jscntxtinlines_h */