Bug 1623932 - Remove support for storing GCCellPtrs in the GCThingList r=caroline

Differential Revision: https://phabricator.services.mozilla.com/D67642

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

js/src/frontend/BytecodeEmitter.cpp

@@ -2438,12 +2438,12 @@ bool BytecodeEmitter::emitScript(ParseNode* body) {
     return false;
   }
 
-  JS::Rooted<BCEScriptStencil> stencil(cx, BCEScriptStencil(*this));
-  if (!stencil.get().init(cx, nslots)) {
+  BCEScriptStencil stencil(*this);
+  if (!stencil.init(cx, nslots)) {
     return false;
   }
 
-  if (!JSScript::fullyInitFromStencil(cx, script, stencil.get())) {
+  if (!JSScript::fullyInitFromStencil(cx, script, stencil)) {
     return false;
   }
 

js/src/frontend/BytecodeSection.cpp

@@ -45,10 +45,7 @@ void GCThingList::finishInnerFunctions() {
 }
 
 AbstractScopePtr GCThingList::getScope(size_t index) const {
-  auto& elem = vector[index].get();
-  if (elem.is<JS::GCCellPtr>()) {
-    return AbstractScopePtr(&elem.as<JS::GCCellPtr>().as<Scope>());
-  }
+  const ScriptThingVariant& elem = vector[index];
   if (elem.is<EmptyGlobalScopeType>()) {
     return AbstractScopePtr(&compilationInfo.cx->global()->emptyGlobalScope());
   }
@@ -68,11 +65,6 @@ bool js::frontend::EmitScriptThingsVector(JSContext* cx,
     uint32_t i;
     mozilla::Span<JS::GCCellPtr>& output;
 
-    bool operator()(const JS::GCCellPtr& value) {
-      output[i] = value;
-      return true;
-    }
-
     bool operator()(const BigIntIndex& index) {
       BigIntCreationData& data = compilationInfo.bigIntData[index];
       BigInt* bi = data.createBigInt(cx);

js/src/frontend/BytecodeSection.h

@@ -46,7 +46,7 @@ class FunctionBox;
 
 struct MOZ_STACK_CLASS GCThingList {
   CompilationInfo& compilationInfo;
-  JS::Rooted<ScriptThingsVector> vector;
+  ScriptThingsVector vector;
 
   // Last emitted function.
   FunctionBox* lastbox = nullptr;
@@ -106,7 +106,7 @@ struct MOZ_STACK_CLASS GCThingList {
     return getScope(*firstScopeIndex);
   }
 
-  ScriptThingsVector stealGCThings() { return std::move(vector.get()); }
+  ScriptThingsVector stealGCThings() { return std::move(vector); }
 };
 
 MOZ_MUST_USE bool EmitScriptThingsVector(JSContext* cx,

js/src/frontend/Frontend2.cpp

@@ -85,7 +85,7 @@ class SmooshScriptStencil : public ScriptStencil {
         result_.is_function, /* funLength = */ 0,
         mozilla::MakeSpan(result_.bytecode.data, result_.bytecode.len),
         mozilla::Span<const jssrcnote>(), mozilla::Span<const uint32_t>(),
-        scopeNotes, mozilla::Span<const JSTryNote>());
+        scopeNotes, mozilla::Span<const TryNote>());
     if (!immutableScriptData) {
       return false;
     }
@@ -352,13 +352,12 @@ JSScript* Smoosh::compileGlobalScript(CompilationInfo& compilationInfo,
   RootedScript script(cx,
                       JSScript::Create(cx, cx->global(), options, sso, extent));
 
-  Rooted<SmooshScriptStencil> stencil(
-      cx, SmooshScriptStencil(cx, smoosh, compilationInfo));
-  if (!stencil.get().init(cx)) {
+  SmooshScriptStencil stencil(cx, smoosh, compilationInfo);
+  if (!stencil.init(cx)) {
     return nullptr;
   }
 
-  if (!JSScript::fullyInitFromStencil(cx, script, stencil.get())) {
+  if (!JSScript::fullyInitFromStencil(cx, script, stencil)) {
     return nullptr;
   }
 

js/src/frontend/FunctionEmitter.cpp

@@ -740,11 +740,11 @@ bool FunctionScriptEmitter::initScript(
     return false;
   }
 
-  JS::Rooted<BCEScriptStencil> stencil(bce_->cx, BCEScriptStencil(*bce_));
-  if (!stencil.get().init(bce_->cx, nslots)) {
+  BCEScriptStencil stencil(*bce_);
+  if (!stencil.init(bce_->cx, nslots)) {
     return false;
   }
-  if (!JSScript::fullyInitFromStencil(bce_->cx, bce_->script, stencil.get())) {
+  if (!JSScript::fullyInitFromStencil(bce_->cx, bce_->script, stencil)) {
     return false;
   }
 

js/src/frontend/ObjLiteral.h

@@ -567,15 +567,4 @@ class ObjLiteralCreationData {
 };
 
 }  // namespace js
-
-namespace JS {
-// Ignore GC tracing for the ObjLiteralCreationData. It contains JSAtom
-// pointers, but these are already held and rooted by the parser. (We must
-// specify GC policy for the creation data because it is placed in the
-// GC-things vector.)
-template <>
-struct GCPolicy<js::ObjLiteralCreationData>
-    : JS::IgnoreGCPolicy<js::ObjLiteralCreationData> {};
-}  // namespace JS
-
 #endif  // frontend_ObjLiteral_h

js/src/frontend/Stencil.h

@@ -444,15 +444,13 @@ class ScopeCreationData {
 class EmptyGlobalScopeType {};
 
 // These types all end up being baked into GC things as part of stencil
-// instantiation. Currently, GCCellPtr is part of this list while we complete
-// Stencil, but eventually will be removed.
+// instantiation.
 using ScriptThingVariant =
-    mozilla::Variant<JS::GCCellPtr, BigIntIndex, ObjLiteralCreationData,
-                     RegExpIndex, ScopeIndex, FunctionIndex,
-                     EmptyGlobalScopeType>;
+    mozilla::Variant<BigIntIndex, ObjLiteralCreationData, RegExpIndex,
+                     ScopeIndex, FunctionIndex, EmptyGlobalScopeType>;
 
 // A vector of things destined to be converted to GC things.
-using ScriptThingsVector = GCVector<ScriptThingVariant>;
+using ScriptThingsVector = Vector<ScriptThingVariant>;
 
 // Data used to instantiate the non-lazy script.
 class ScriptStencil {
@@ -485,7 +483,7 @@ class ScriptStencil {
 
   js::frontend::FunctionBox* functionBox = nullptr;
 
-  ScriptStencil(JSContext* cx) : gcThings(cx) {}
+  explicit ScriptStencil(JSContext* cx) : gcThings(cx) {}
 
   // Store all GC things into `gcthings`.
   // `gcthings.Length()` is `this.ngcthings`.
@@ -498,8 +496,6 @@ class ScriptStencil {
 
   // Call `FunctionBox::finish` for all inner functions.
   virtual void finishInnerFunctions() const = 0;
-
-  void trace(JSTracer* trc) { gcThings.trace(trc); }
 };
 
 } /* namespace frontend */
@@ -513,17 +509,5 @@ struct GCPolicy<js::frontend::ScopeCreationData*> {
     (*data)->trace(trc);
   }
 };
-
-template <typename T>
-struct GCPolicy<js::frontend::TypedIndex<T>>
-    : JS::IgnoreGCPolicy<js::frontend::TypedIndex<T>> {};
-
-template <>
-struct GCPolicy<js::frontend::FunctionIndex>
-    : JS::IgnoreGCPolicy<js::frontend::FunctionIndex> {};
-
-template <>
-struct GCPolicy<js::frontend::EmptyGlobalScopeType>
-    : JS::IgnoreGCPolicy<js::frontend::EmptyGlobalScopeType> {};
 }  // namespace JS
 #endif /* frontend_Stencil_h */