1320403 - Move JSFunction::EXPR_BODY to JSScript, LazyScript, and FunctionBox.

js/src/builtin/ReflectParse.cpp

@@ -3407,12 +3407,7 @@ ASTSerializer::function(ParseNode* pn, ASTType type, MutableHandleValue dst)
         : GeneratorStyle::None;
 
     bool isAsync = pn->pn_funbox->isAsync();
-    bool isExpression =
+    bool isExpression = pn->pn_funbox->isExprBody();
-#if JS_HAS_EXPR_CLOSURES
-        func->isExprBody();
-#else
-        false;
-#endif
 
     RootedValue id(cx);
     RootedAtom funcAtom(cx, func->explicitName());

js/src/frontend/Parser.cpp

@@ -474,6 +474,7 @@ FunctionBox::FunctionBox(ExclusiveContext* cx, LifoAlloc& alloc, ObjectBox* trac
     usesThis(false),
     usesReturn(false),
     hasRest_(false),
+    isExprBody_(false),
     funCxFlags()
 {
     // Functions created at parse time may be set singleton after parsing and
@@ -2264,6 +2265,8 @@ Parser<SyntaxParseHandler>::finishFunction(bool isStandaloneFunction /* = false
     lazy->setAsyncKind(funbox->asyncKind());
     if (funbox->hasRest())
         lazy->setHasRest();
+    if (funbox->isExprBody())
+        lazy->setIsExprBody();
     if (funbox->isLikelyConstructorWrapper())
         lazy->setLikelyConstructorWrapper();
     if (funbox->isDerivedClassConstructor())
@@ -3030,6 +3033,8 @@ Parser<FullParseHandler>::skipLazyInnerFunction(ParseNode* pn, uint32_t preludeS
     LazyScript* lazy = fun->lazyScript();
     if (lazy->needsHomeObject())
         funbox->setNeedsHomeObject();
+    if (lazy->isExprBody())
+        funbox->setIsExprBody();
 
     PropagateTransitiveParseFlags(lazy, pc->sc());
 
@@ -3042,10 +3047,15 @@ Parser<FullParseHandler>::skipLazyInnerFunction(ParseNode* pn, uint32_t preludeS
     if (!tokenStream.advance(fun->lazyScript()->end() - userbufBase))
         return false;
 
-    if (kind == Statement && fun->isExprBody()) {
+#if JS_HAS_EXPR_CLOSURES
+    // Only expression closure can be Statement kind.
+    // If we remove expression closure, we can remove isExprBody flag from
+    // LazyScript and JSScript.
+    if (kind == Statement && funbox->isExprBody()) {
         if (!matchOrInsertSemicolonAfterExpression())
             return false;
     }
+#endif
 
     return true;
 }
@@ -3490,9 +3500,7 @@ Parser<ParseHandler>::functionFormalParametersAndBody(InHandling inHandling,
 
         tokenStream.ungetToken();
         bodyType = ExpressionBody;
-#if JS_HAS_EXPR_CLOSURES
+        funbox->setIsExprBody();
-        fun->setIsExprBody();
-#endif
     }
 
     // Arrow function parameters inherit yieldHandling from the enclosing
@@ -6130,7 +6138,7 @@ Parser<ParseHandler>::yieldExpression(InHandling inHandling)
 
         if (pc->funHasReturnExpr
 #if JS_HAS_EXPR_CLOSURES
-            || pc->functionBox()->function()->isExprBody()
+            || pc->functionBox()->isExprBody()
 #endif
             )
         {

js/src/frontend/SharedContext.h

@@ -473,6 +473,9 @@ class FunctionBox : public ObjectBox, public SharedContext
     bool            usesThis:1;             /* contains 'this' */
     bool            usesReturn:1;           /* contains a 'return' statement */
     bool            hasRest_:1;             /* has rest parameter */
+    bool            isExprBody_:1;          /* arrow function with expression
+                                             * body or expression closure:
+                                             * function(x) x*x */
 
     FunctionContextFlags funCxFlags;
 
@@ -546,6 +549,11 @@ class FunctionBox : public ObjectBox, public SharedContext
         hasRest_ = true;
     }
 
+    bool isExprBody() const { return isExprBody_; }
+    void setIsExprBody() {
+        isExprBody_ = true;
+    }
+
     void setGeneratorKind(GeneratorKind kind) {
         // A generator kind can be set at initialization, or when "yield" is
         // first seen.  In both cases the transition can only happen from

js/src/jsfun.cpp

@@ -980,8 +980,6 @@ js::FunctionToString(JSContext* cx, HandleFunction fun, bool prettyPrint)
             return nullptr;
         }
     } else {
-        MOZ_ASSERT(!fun->isExprBody());
-
         bool derived = fun->infallibleIsDefaultClassConstructor(cx);
         if (derived && fun->isDerivedClassConstructor()) {
             if (!AppendPrelude() ||

js/src/jsfun.h

@@ -58,8 +58,6 @@ class JSFunction : public js::NativeObject
         CONSTRUCTOR      = 0x0002,  /* function that can be called as a constructor */
         EXTENDED         = 0x0004,  /* structure is FunctionExtended */
         BOUND_FUN        = 0x0008,  /* function was created with Function.prototype.bind. */
-        EXPR_BODY        = 0x0010,  /* arrow function with expression body or
-                                     * expression closure: function(x) x*x */
         HAS_GUESSED_ATOM = 0x0020,  /* function had no explicit name, but a
                                        name was guessed for it anyway */
         LAMBDA           = 0x0040,  /* function comes from a FunctionExpression, ArrowFunction, or
@@ -102,7 +100,7 @@ class JSFunction : public js::NativeObject
         INTERPRETED_GENERATOR = INTERPRETED,
         NO_XDR_FLAGS = RESOLVED_LENGTH | RESOLVED_NAME,
 
-        STABLE_ACROSS_CLONES = CONSTRUCTOR | EXPR_BODY | HAS_GUESSED_ATOM | LAMBDA |
+        STABLE_ACROSS_CLONES = CONSTRUCTOR | HAS_GUESSED_ATOM | LAMBDA |
                                SELF_HOSTED | HAS_COMPILE_TIME_NAME | FUNCTION_KIND_MASK
     };
 
@@ -187,7 +185,6 @@ class JSFunction : public js::NativeObject
     bool isAsmJSNative()            const { return kind() == AsmJS; }
 
     /* Possible attributes of an interpreted function: */
-    bool isExprBody()               const { return flags() & EXPR_BODY; }
     bool hasCompileTimeName()       const { return flags() & HAS_COMPILE_TIME_NAME; }
     bool hasGuessedAtom()           const { return flags() & HAS_GUESSED_ATOM; }
     bool isLambda()                 const { return flags() & LAMBDA; }
@@ -290,11 +287,6 @@ class JSFunction : public js::NativeObject
         flags_ |= SELF_HOSTED;
     }
 
-    // Can be called multiple times by the parser.
-    void setIsExprBody() {
-        flags_ |= EXPR_BODY;
-    }
-
     void setArrow() {
         setKind(Arrow);
     }

js/src/jsscript.cpp

@@ -319,6 +319,7 @@ js::XDRScript(XDRState<mode>* xdr, HandleScope scriptEnclosingScope, HandleScrip
         IsStarGenerator,
         IsAsync,
         HasRest,
+        IsExprBody,
         OwnSource,
         ExplicitUseStrict,
         SelfHosted,
@@ -436,6 +437,8 @@ js::XDRScript(XDRState<mode>* xdr, HandleScope scriptEnclosingScope, HandleScrip
             scriptBits |= (1 << IsAsync);
         if (script->hasRest())
             scriptBits |= (1 << HasRest);
+        if (script->isExprBody())
+            scriptBits |= (1 << IsExprBody);
         if (script->hasSingletons())
             scriptBits |= (1 << HasSingleton);
         if (script->treatAsRunOnce())
@@ -589,6 +592,8 @@ js::XDRScript(XDRState<mode>* xdr, HandleScope scriptEnclosingScope, HandleScrip
             script->setAsyncKind(AsyncFunction);
         if (scriptBits & (1 << HasRest))
             script->setHasRest();
+        if (scriptBits & (1 << IsExprBody))
+            script->setIsExprBody();
     }
 
     JS_STATIC_ASSERT(sizeof(jsbytecode) == 1);
@@ -2660,6 +2665,8 @@ JSScript::initFromFunctionBox(ExclusiveContext* cx, HandleScript script,
     script->setAsyncKind(funbox->asyncKind());
     if (funbox->hasRest())
         script->setHasRest();
+    if (funbox->isExprBody())
+        script->setIsExprBody();
 
     PositionalFormalParameterIter fi(script);
     while (fi && !fi.closedOver())
@@ -3320,6 +3327,7 @@ js::detail::CopyScript(JSContext* cx, HandleScript src, HandleScript dst,
     dst->isDefaultClassConstructor_ = src->isDefaultClassConstructor();
     dst->isAsync_ = src->asyncKind() == AsyncFunction;
     dst->hasRest_ = src->hasRest_;
+    dst->isExprBody_ = src->isExprBody_;
 
     if (nconsts != 0) {
         GCPtrValue* vector = Rebase<GCPtrValue>(dst, src, src->consts()->vector);
@@ -4059,6 +4067,7 @@ LazyScript::Create(ExclusiveContext* cx, HandleFunction fun,
     p.hasThisBinding = false;
     p.isAsync = false;
     p.hasRest = false;
+    p.isExprBody = false;
     p.numClosedOverBindings = closedOverBindings.length();
     p.numInnerFunctions = innerFunctions.length();
     p.generatorKindBits = GeneratorKindAsBits(NotGenerator);

js/src/jsscript.h

@@ -1021,6 +1021,7 @@ class JSScript : public js::gc::TenuredCell
     bool isAsync_:1;
 
     bool hasRest_:1;
+    bool isExprBody_:1;
 
     // Add padding so JSScript is gc::Cell aligned. Make padding protected
     // instead of private to suppress -Wunused-private-field compiler warnings.
@@ -1329,6 +1330,13 @@ class JSScript : public js::gc::TenuredCell
         hasRest_ = true;
     }
 
+    bool isExprBody() const {
+        return isExprBody_;
+    }
+    void setIsExprBody() {
+        isExprBody_ = true;
+    }
+
     void setNeedsHomeObject() {
         needsHomeObject_ = true;
     }
@@ -1936,7 +1944,7 @@ class LazyScript : public gc::TenuredCell
 #endif
 
   private:
-    static const uint32_t NumClosedOverBindingsBits = 21;
+    static const uint32_t NumClosedOverBindingsBits = 20;
     static const uint32_t NumInnerFunctionsBits = 20;
 
     struct PackedView {
@@ -1946,7 +1954,12 @@ class LazyScript : public gc::TenuredCell
         uint32_t shouldDeclareArguments : 1;
         uint32_t hasThisBinding : 1;
         uint32_t isAsync : 1;
+        uint32_t isExprBody : 1;
+
         uint32_t numClosedOverBindings : NumClosedOverBindingsBits;
+
+        // -- 32bit boundary --
+
         uint32_t numInnerFunctions : NumInnerFunctionsBits;
 
         uint32_t generatorKindBits : 2;
@@ -2104,6 +2117,13 @@ class LazyScript : public gc::TenuredCell
         p_.hasRest = true;
     }
 
+    bool isExprBody() const {
+        return p_.isExprBody;
+    }
+    void setIsExprBody() {
+        p_.isExprBody = true;
+    }
+
     bool strict() const {
         return p_.strict;
     }

js/src/shell/js.cpp

@@ -2689,7 +2689,7 @@ DisassembleScript(JSContext* cx, HandleScript script, HandleFunction fun,
             if (sp->put(" CONSTRUCTOR") < 0)
                 return false;
         }
-        if (fun->isExprBody()) {
+        if (script->isExprBody()) {
             if (sp->put(" EXPRESSION_CLOSURE") < 0)
                 return false;
         }

js/src/wasm/AsmJS.cpp

@@ -3250,10 +3250,9 @@ CheckModuleLevelName(ModuleValidator& m, ParseNode* usepn, PropertyName* name)
 static bool
 CheckFunctionHead(ModuleValidator& m, ParseNode* fn)
 {
-    JSFunction* fun = FunctionObject(fn);
     if (fn->pn_funbox->hasRest())
         return m.fail(fn, "rest args not allowed");
-    if (fun->isExprBody())
+    if (fn->pn_funbox->isExprBody())
         return m.fail(fn, "expression closures not allowed");
     if (fn->pn_funbox->hasDestructuringArgs)
         return m.fail(fn, "destructuring args not allowed");