Commit f88eca81 authored Oct 09, 2019 by Jon Coppeard

Bug 1585921 - Use root marking functions to trace unbarriered pointers in...

Bug 1585921 - Use root marking functions to trace unbarriered pointers in GCPolicy traits since this is only safe when we're marking roots r=sfink

The root marking functions have assertions that will catch this being used outside of heap marking.

Differential Revision: https://phabricator.services.mozilla.com/D48534

--HG--
extra : moz-landing-system : lando

parent f5b37220

js/public/GCPolicyAPI.h

+3 −3

Original line number	Original line	Diff line number	Diff line
	@@ -109,9 +109,9 @@ struct GCPointerPolicy {
	"Non-pointer type not allowed for GCPointerPolicy");		"Non-pointer type not allowed for GCPointerPolicy");

	static void trace(JSTracer* trc, T* vp, const char* name) {		static void trace(JSTracer* trc, T* vp, const char* name) {
	if (*vp) {		// It's not safe to trace unbarriered pointers except as part of root
	js::UnsafeTraceManuallyBarrieredEdge(trc, vp, name);		// marking.
	}		UnsafeTraceRoot(trc, vp, name);
	}		}
	static bool needsSweep(T* vp) {		static bool needsSweep(T* vp) {
	if (*vp) {		if (*vp) {

js/public/Id.h

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -170,7 +170,9 @@ namespace JS {
	template <>		template <>
	struct GCPolicy<jsid> {		struct GCPolicy<jsid> {
	static void trace(JSTracer* trc, jsid* idp, const char* name) {		static void trace(JSTracer* trc, jsid* idp, const char* name) {
	js::UnsafeTraceManuallyBarrieredEdge(trc, idp, name);		// It's not safe to trace unbarriered pointers except as part of root
			// marking.
			UnsafeTraceRoot(trc, idp, name);
	}		}
	static bool isValid(jsid id) {		static bool isValid(jsid id) {
	return !JSID_IS_GCTHING(id) \|\|		return !JSID_IS_GCTHING(id) \|\|

js/public/Value.h

+3 −1

Original line number	Original line	Diff line number	Diff line
	@@ -1077,7 +1077,9 @@ JS_PUBLIC_API void HeapValueWriteBarriers(Value* valuep, const Value& prev,
	template <>		template <>
	struct GCPolicy<JS::Value> {		struct GCPolicy<JS::Value> {
	static void trace(JSTracer* trc, Value* v, const char* name) {		static void trace(JSTracer* trc, Value* v, const char* name) {
	js::UnsafeTraceManuallyBarrieredEdge(trc, v, name);		// It's not safe to trace unbarriered pointers except as part of root
			// marking.
			UnsafeTraceRoot(trc, v, name);
	}		}
	static bool isTenured(const Value& thing) {		static bool isTenured(const Value& thing) {
	return !thing.isGCThing() \|\| !IsInsideNursery(thing.toGCThing());		return !thing.isGCThing() \|\| !IsInsideNursery(thing.toGCThing());

js/src/gc/Policy.h

+4 −3

Original line number	Original line	Diff line number	Diff line
	@@ -44,9 +44,10 @@ struct InternalGCPointerPolicy : public JS::GCPointerPolicy<T> {
	}		}
	}		}
	static void trace(JSTracer* trc, T* vp, const char* name) {		static void trace(JSTracer* trc, T* vp, const char* name) {
	if (*vp) {		// It's not safe to trace unbarriered pointers except as part of root
	TraceManuallyBarrieredEdge(trc, vp, name);		// marking. If you get an assertion here you probably need to add a barrier,
	}		// e.g. HeapPtr<T>.
			TraceNullableRoot(trc, vp, name);
	}		}
	};		};

js/src/vm/HelperThreads.cpp

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -532,7 +532,7 @@ void ParseTask::trace(JSTracer* trc) {
	return;		return;
	}		}

	TraceManuallyBarrieredEdge(trc, &parseGlobal, "ParseTask::parseGlobal");		TraceRoot(trc, &parseGlobal, "ParseTask::parseGlobal");
	scripts.trace(trc);		scripts.trace(trc);
	sourceObjects.trace(trc);		sourceObjects.trace(trc);
	}		}