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Diffstat (limited to '')
| -rw-r--r-- | js/src/debugger/DebugScript.cpp | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/js/src/debugger/DebugScript.cpp b/js/src/debugger/DebugScript.cpp new file mode 100644 index 0000000000..610784c228 --- /dev/null +++ b/js/src/debugger/DebugScript.cpp @@ -0,0 +1,411 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * 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/. */ + +#include "debugger/DebugScript.h" + +#include "mozilla/Assertions.h" // for AssertionConditionType +#include "mozilla/HashTable.h" // for HashMapEntry, HashTable<>::Ptr, HashMap +#include "mozilla/UniquePtr.h" // for UniquePtr + +#include <utility> // for std::move + +#include "debugger/DebugAPI.h" // for DebugAPI +#include "debugger/Debugger.h" // for JSBreakpointSite, Breakpoint +#include "gc/Cell.h" // for TenuredCell +#include "gc/GCContext.h" // for JS::GCContext +#include "gc/GCEnum.h" // for MemoryUse, MemoryUse::BreakpointSite +#include "gc/Marking.h" // for IsAboutToBeFinalized +#include "gc/Zone.h" // for Zone +#include "gc/ZoneAllocator.h" // for AddCellMemory +#include "jit/BaselineJIT.h" // for BaselineScript +#include "vm/BytecodeIterator.h" // for AllBytecodesIterable +#include "vm/JSContext.h" // for JSContext +#include "vm/JSScript.h" // for JSScript, DebugScriptMap +#include "vm/NativeObject.h" // for NativeObject +#include "vm/Realm.h" // for Realm, AutoRealm +#include "vm/Runtime.h" // for ReportOutOfMemory +#include "vm/Stack.h" // for ActivationIterator, Activation + +#include "gc/GC-inl.h" // for ZoneCellIter +#include "gc/GCContext-inl.h" // for JS::GCContext::free_ +#include "gc/Marking-inl.h" // for CheckGCThingAfterMovingGC +#include "gc/WeakMap-inl.h" // for WeakMap::remove +#include "vm/BytecodeIterator-inl.h" // for AllBytecodesIterable +#include "vm/JSContext-inl.h" // for JSContext::check +#include "vm/JSObject-inl.h" // for NewObjectWithGivenProto +#include "vm/JSScript-inl.h" // for JSScript::hasBaselineScript +#include "vm/Realm-inl.h" // for AutoRealm::AutoRealm + +namespace js { + +const JSClass DebugScriptObject::class_ = { + "DebugScriptObject", + JSCLASS_HAS_RESERVED_SLOTS(SlotCount) | JSCLASS_BACKGROUND_FINALIZE, + &classOps_, JS_NULL_CLASS_SPEC}; + +const JSClassOps DebugScriptObject::classOps_ = { + nullptr, // addProperty + nullptr, // delProperty + nullptr, // enumerate + nullptr, // newEnumerate + nullptr, // resolve + nullptr, // mayResolve + DebugScriptObject::finalize, // finalize + nullptr, // call + nullptr, // construct + DebugScriptObject::trace, // trace +}; + +/* static */ +DebugScriptObject* DebugScriptObject::create(JSContext* cx, + UniqueDebugScript debugScript, + size_t nbytes) { + auto* object = NewObjectWithGivenProto<DebugScriptObject>(cx, nullptr); + if (!object) { + return nullptr; + } + + object->initReservedSlot(ScriptSlot, PrivateValue(debugScript.release())); + AddCellMemory(object, nbytes, MemoryUse::ScriptDebugScript); + + return object; +} + +DebugScript* DebugScriptObject::debugScript() const { + return maybePtrFromReservedSlot<DebugScript>(ScriptSlot); +} + +/* static */ +void DebugScriptObject::trace(JSTracer* trc, JSObject* obj) { + DebugScript* debugScript = obj->as<DebugScriptObject>().debugScript(); + if (debugScript) { + debugScript->trace(trc); + } +} + +/* static */ +void DebugScriptObject::finalize(JS::GCContext* gcx, JSObject* obj) { + DebugScriptObject* object = &obj->as<DebugScriptObject>(); + DebugScript* debugScript = object->debugScript(); + if (debugScript) { + debugScript->delete_(gcx, object); + } +} + +/* static */ +DebugScript* DebugScript::get(JSScript* script) { + MOZ_ASSERT(script->hasDebugScript()); + DebugScriptMap* map = script->zone()->debugScriptMap; + MOZ_ASSERT(map); + DebugScriptMap::Ptr p = map->lookupUnbarriered(script); + MOZ_ASSERT(p); + return p->value().get()->as<DebugScriptObject>().debugScript(); +} + +/* static */ +DebugScript* DebugScript::getOrCreate(JSContext* cx, HandleScript script) { + cx->check(script); + + if (script->hasDebugScript()) { + return get(script); + } + + size_t nbytes = allocSize(script->length()); + UniqueDebugScript debug( + reinterpret_cast<DebugScript*>(cx->pod_calloc<uint8_t>(nbytes))); + if (!debug) { + return nullptr; + } + + debug->codeLength = script->length(); + + Rooted<DebugScriptObject*> object( + cx, DebugScriptObject::create(cx, std::move(debug), nbytes)); + if (!object) { + return nullptr; + } + + /* Create zone's debugScriptMap if necessary. */ + Zone* zone = script->zone(); + MOZ_ASSERT(cx->zone() == zone); + if (!zone->debugScriptMap) { + DebugScriptMap* map = cx->new_<DebugScriptMap>(cx); + if (!map) { + return nullptr; + } + + zone->debugScriptMap = map; + } + + MOZ_ASSERT(script->hasBytecode()); + + if (!zone->debugScriptMap->putNew(script.get(), object.get())) { + ReportOutOfMemory(cx); + return nullptr; + } + + // It is safe to set this: we can't fail after this point. + script->setHasDebugScript(true); + + /* + * Ensure that any Interpret() instances running on this script have + * interrupts enabled. The interrupts must stay enabled until the + * debug state is destroyed. + */ + for (ActivationIterator iter(cx); !iter.done(); ++iter) { + if (iter->isInterpreter()) { + iter->asInterpreter()->enableInterruptsIfRunning(script); + } + } + + return object->debugScript(); +} + +/* static */ +JSBreakpointSite* DebugScript::getBreakpointSite(JSScript* script, + jsbytecode* pc) { + uint32_t offset = script->pcToOffset(pc); + return script->hasDebugScript() ? get(script)->breakpoints[offset] : nullptr; +} + +/* static */ +JSBreakpointSite* DebugScript::getOrCreateBreakpointSite(JSContext* cx, + HandleScript script, + jsbytecode* pc) { + AutoRealm ar(cx, script); + + DebugScript* debug = getOrCreate(cx, script); + if (!debug) { + return nullptr; + } + + JSBreakpointSite*& site = debug->breakpoints[script->pcToOffset(pc)]; + + if (!site) { + site = cx->new_<JSBreakpointSite>(script, pc); + if (!site) { + return nullptr; + } + debug->numSites++; + AddCellMemory(script, sizeof(JSBreakpointSite), MemoryUse::BreakpointSite); + + if (script->hasBaselineScript()) { + script->baselineScript()->toggleDebugTraps(script, pc); + } + } + + return site; +} + +/* static */ +void DebugScript::destroyBreakpointSite(JS::GCContext* gcx, JSScript* script, + jsbytecode* pc) { + DebugScript* debug = get(script); + JSBreakpointSite*& site = debug->breakpoints[script->pcToOffset(pc)]; + MOZ_ASSERT(site); + MOZ_ASSERT(site->isEmpty()); + + site->delete_(gcx); + site = nullptr; + + debug->numSites--; + if (!debug->needed()) { + DebugAPI::removeDebugScript(gcx, script); + } + + if (script->hasBaselineScript()) { + script->baselineScript()->toggleDebugTraps(script, pc); + } +} + +/* static */ +void DebugScript::clearBreakpointsIn(JS::GCContext* gcx, JSScript* script, + Debugger* dbg, JSObject* handler) { + MOZ_ASSERT(script); + // Breakpoints hold wrappers in the script's compartment for the handler. Make + // sure we don't try to search for the unwrapped handler. + MOZ_ASSERT_IF(handler, script->compartment() == handler->compartment()); + + if (!script->hasDebugScript()) { + return; + } + + AllBytecodesIterable iter(script); + for (BytecodeLocation loc : iter) { + JSBreakpointSite* site = getBreakpointSite(script, loc.toRawBytecode()); + if (site) { + Breakpoint* nextbp; + for (Breakpoint* bp = site->firstBreakpoint(); bp; bp = nextbp) { + nextbp = bp->nextInSite(); + if ((!dbg || bp->debugger == dbg) && + (!handler || bp->getHandler() == handler)) { + bp->remove(gcx); + } + } + } + } +} + +#ifdef DEBUG +/* static */ +uint32_t DebugScript::getStepperCount(JSScript* script) { + return script->hasDebugScript() ? get(script)->stepperCount : 0; +} +#endif // DEBUG + +/* static */ +bool DebugScript::incrementStepperCount(JSContext* cx, HandleScript script) { + cx->check(script); + MOZ_ASSERT(cx->realm()->isDebuggee()); + + AutoRealm ar(cx, script); + + DebugScript* debug = getOrCreate(cx, script); + if (!debug) { + return false; + } + + debug->stepperCount++; + + if (debug->stepperCount == 1) { + if (script->hasBaselineScript()) { + script->baselineScript()->toggleDebugTraps(script, nullptr); + } + } + + return true; +} + +/* static */ +void DebugScript::decrementStepperCount(JS::GCContext* gcx, JSScript* script) { + DebugScript* debug = get(script); + MOZ_ASSERT(debug); + MOZ_ASSERT(debug->stepperCount > 0); + + debug->stepperCount--; + + if (debug->stepperCount == 0) { + if (script->hasBaselineScript()) { + script->baselineScript()->toggleDebugTraps(script, nullptr); + } + + if (!debug->needed()) { + DebugAPI::removeDebugScript(gcx, script); + } + } +} + +/* static */ +bool DebugScript::incrementGeneratorObserverCount(JSContext* cx, + HandleScript script) { + cx->check(script); + MOZ_ASSERT(cx->realm()->isDebuggee()); + + AutoRealm ar(cx, script); + + DebugScript* debug = getOrCreate(cx, script); + if (!debug) { + return false; + } + + debug->generatorObserverCount++; + + // It is our caller's responsibility, before bumping the generator observer + // count, to make sure that the baseline code includes the necessary + // JSOp::AfterYield instrumentation by calling + // {ensure,update}ExecutionObservabilityOfScript. + MOZ_ASSERT_IF(script->hasBaselineScript(), + script->baselineScript()->hasDebugInstrumentation()); + + return true; +} + +/* static */ +void DebugScript::decrementGeneratorObserverCount(JS::GCContext* gcx, + JSScript* script) { + DebugScript* debug = get(script); + MOZ_ASSERT(debug); + MOZ_ASSERT(debug->generatorObserverCount > 0); + + debug->generatorObserverCount--; + + if (!debug->needed()) { + DebugAPI::removeDebugScript(gcx, script); + } +} + +void DebugScript::trace(JSTracer* trc) { + for (size_t i = 0; i < codeLength; i++) { + JSBreakpointSite* site = breakpoints[i]; + if (site) { + site->trace(trc); + } + } +} + +/* static */ +void DebugAPI::removeDebugScript(JS::GCContext* gcx, JSScript* script) { + if (script->hasDebugScript()) { + if (IsAboutToBeFinalizedUnbarriered(script)) { + // The script is dying and all breakpoint data will be cleaned up. + return; + } + + DebugScriptMap* map = script->zone()->debugScriptMap; + MOZ_ASSERT(map); + DebugScriptMap::Ptr p = map->lookupUnbarriered(script); + MOZ_ASSERT(p); + map->remove(p); + script->setHasDebugScript(false); + + // The DebugScript will be destroyed at the next GC when its owning + // DebugScriptObject dies. + } +} + +void DebugScript::delete_(JS::GCContext* gcx, DebugScriptObject* owner) { + for (size_t i = 0; i < codeLength; i++) { + JSBreakpointSite* site = breakpoints[i]; + if (site) { + site->delete_(gcx); + } + } + + gcx->free_(owner, this, allocSize(codeLength), MemoryUse::ScriptDebugScript); +} + +#ifdef JSGC_HASH_TABLE_CHECKS +/* static */ +void DebugAPI::checkDebugScriptAfterMovingGC(DebugScript* ds) { + for (uint32_t i = 0; i < ds->numSites; i++) { + JSBreakpointSite* site = ds->breakpoints[i]; + if (site) { + CheckGCThingAfterMovingGC(site->script.get()); + } + } +} +#endif // JSGC_HASH_TABLE_CHECKS + +/* static */ +bool DebugAPI::stepModeEnabledSlow(JSScript* script) { + return DebugScript::get(script)->stepperCount > 0; +} + +/* static */ +bool DebugAPI::hasBreakpointsAtSlow(JSScript* script, jsbytecode* pc) { + JSBreakpointSite* site = DebugScript::getBreakpointSite(script, pc); + return !!site; +} + +/* static */ +void DebugAPI::traceDebugScriptMap(JSTracer* trc, DebugScriptMap* map) { + map->trace(trc); +} + +/* static */ +void DebugAPI::deleteDebugScriptMap(DebugScriptMap* map) { js_delete(map); } + +} // namespace js |