Bug 1331092 - Part 2: Implement Async Generator except yield*.

Tag #1287

5 files changed, 54 insertions, 16 deletions

diff --git a/js/src/frontend/BytecodeCompiler.cpp b/js/src/frontend/BytecodeCompiler.cpp
index 7760c4b2e..ccfe3cd2e 100644
--- a/js/src/frontend/BytecodeCompiler.cpp
+++ b/js/src/frontend/BytecodeCompiler.cpp
@@ -729,3 +729,16 @@ frontend::CompileStandaloneAsyncFunction(JSContext* cx, MutableHandleFunction fu
                               TraceLogger_ParserCompileFunction);
     return compiler.compileStandaloneFunction(fun, NotGenerator, AsyncFunction, parameterListEnd);
 }
+
+bool
+frontend::CompileStandaloneAsyncGenerator(JSContext* cx, MutableHandleFunction fun,
+                                          const ReadOnlyCompileOptions& options,
+                                          JS::SourceBufferHolder& srcBuf,
+                                          Maybe<uint32_t> parameterListEnd)
+{
+    RootedScope emptyGlobalScope(cx, &cx->global()->emptyGlobalScope());
+
+    BytecodeCompiler compiler(cx, cx->tempLifoAlloc(), options, srcBuf, emptyGlobalScope,
+                              TraceLogger_ParserCompileFunction);
+    return compiler.compileStandaloneFunction(fun, StarGenerator, AsyncFunction, parameterListEnd);
+}
diff --git a/js/src/frontend/BytecodeCompiler.h b/js/src/frontend/BytecodeCompiler.h
index 0bc1ab2ab..029fbe632 100644
--- a/js/src/frontend/BytecodeCompiler.h
+++ b/js/src/frontend/BytecodeCompiler.h
@@ -85,6 +85,12 @@ CompileStandaloneAsyncFunction(JSContext* cx, MutableHandleFunction fun,
                                mozilla::Maybe<uint32_t> parameterListEnd);
 
 MOZ_MUST_USE bool
+CompileStandaloneAsyncGenerator(JSContext* cx, MutableHandleFunction fun,
+                                const ReadOnlyCompileOptions& options,
+                                JS::SourceBufferHolder& srcBuf,
+                                mozilla::Maybe<uint32_t> parameterListEnd);
+
+MOZ_MUST_USE bool
 CompileAsyncFunctionBody(JSContext* cx, MutableHandleFunction fun,
                          const ReadOnlyCompileOptions& options,
                          Handle<PropertyNameVector> formals, JS::SourceBufferHolder& srcBuf);
diff --git a/js/src/frontend/BytecodeEmitter.cpp b/js/src/frontend/BytecodeEmitter.cpp
index a98016d63..9d6a68609 100644
--- a/js/src/frontend/BytecodeEmitter.cpp
+++ b/js/src/frontend/BytecodeEmitter.cpp
@@ -8067,7 +8067,8 @@ BytecodeEmitter::emitFunction(ParseNode* pn, bool needsProto)
         MOZ_ASSERT(fun->isArrow() == (pn->getOp() == JSOP_LAMBDA_ARROW));
         if (funbox->isAsync()) {
             MOZ_ASSERT(!needsProto);
-            return emitAsyncWrapper(index, funbox->needsHomeObject(), fun->isArrow());
+            return emitAsyncWrapper(index, funbox->needsHomeObject(), fun->isArrow(),
+                                    fun->isStarGenerator());
         }
 
         if (fun->isArrow()) {
@@ -8122,8 +8123,11 @@ BytecodeEmitter::emitFunction(ParseNode* pn, bool needsProto)
             MOZ_ASSERT(pn->getOp() == JSOP_NOP);
             switchToPrologue();
             if (funbox->isAsync()) {
-                if (!emitAsyncWrapper(index, fun->isMethod(), fun->isArrow()))
+                if (!emitAsyncWrapper(index, fun->isMethod(), fun->isArrow(),
+                                      fun->isStarGenerator()))
+                {
                     return false;
+                }
             } else {
                 if (!emitIndex32(JSOP_LAMBDA, index))
                     return false;
@@ -8139,10 +8143,12 @@ BytecodeEmitter::emitFunction(ParseNode* pn, bool needsProto)
         // initialize the binding name of the function in the current scope.
 
         bool isAsync = funbox->isAsync();
-        auto emitLambda = [index, isAsync](BytecodeEmitter* bce, const NameLocation&, bool) {
+        bool isStarGenerator = funbox->isStarGenerator();
+        auto emitLambda = [index, isAsync, isStarGenerator](BytecodeEmitter* bce,
+                                                            const NameLocation&, bool) {
             if (isAsync) {
                 return bce->emitAsyncWrapper(index, /* needsHomeObject = */ false,
-                                             /* isArrow = */ false);
+                                             /* isArrow = */ false, isStarGenerator);
             }
             return bce->emitIndexOp(JSOP_LAMBDA, index);
         };
@@ -8177,7 +8183,8 @@ BytecodeEmitter::emitAsyncWrapperLambda(unsigned index, bool isArrow) {
 }
 
 bool
-BytecodeEmitter::emitAsyncWrapper(unsigned index, bool needsHomeObject, bool isArrow)
+BytecodeEmitter::emitAsyncWrapper(unsigned index, bool needsHomeObject, bool isArrow,
+                                  bool isStarGenerator)
 {
     // needsHomeObject can be true for propertyList for extended class.
     // In that case push both unwrapped and wrapped function, in order to
@@ -8209,8 +8216,13 @@ BytecodeEmitter::emitAsyncWrapper(unsigned index, bool needsHomeObject, bool isA
         if (!emit1(JSOP_DUP))
             return false;
     }
-    if (!emit1(JSOP_TOASYNC))
-        return false;
+    if (isStarGenerator) {
+        if (!emit1(JSOP_TOASYNCGEN))
+            return false;
+    } else {
+        if (!emit1(JSOP_TOASYNC))
+            return false;
+    }
     return true;
 }
 
diff --git a/js/src/frontend/BytecodeEmitter.h b/js/src/frontend/BytecodeEmitter.h
index f3f78df16..67e329489 100644
--- a/js/src/frontend/BytecodeEmitter.h
+++ b/js/src/frontend/BytecodeEmitter.h
@@ -620,7 +620,8 @@ struct MOZ_STACK_CLASS BytecodeEmitter
     MOZ_MUST_USE bool emitPropIncDec(ParseNode* pn);
 
     MOZ_MUST_USE bool emitAsyncWrapperLambda(unsigned index, bool isArrow);
-    MOZ_MUST_USE bool emitAsyncWrapper(unsigned index, bool needsHomeObject, bool isArrow);
+    MOZ_MUST_USE bool emitAsyncWrapper(unsigned index, bool needsHomeObject, bool isArrow,
+                                       bool isStarGenerator);
 
     MOZ_MUST_USE bool emitComputedPropertyName(ParseNode* computedPropName);
 
diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 3ae5890ac..7704cf65a 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -3785,10 +3785,12 @@ Parser<ParseHandler>::functionStmt(uint32_t toStringStart, YieldHandling yieldHa
 
     GeneratorKind generatorKind = NotGenerator;
     if (tt == TOK_MUL) {
+#ifdef RELEASE_OR_BETA
         if (asyncKind != SyncFunction) {
             error(JSMSG_ASYNC_GENERATOR);
             return null();
         }
+#endif
         generatorKind = StarGenerator;
         if (!tokenStream.getToken(&tt))
             return null();
@@ -3857,10 +3859,12 @@ Parser<ParseHandler>::functionExpr(uint32_t toStringStart, InvokedPrediction inv
         return null();
 
     if (tt == TOK_MUL) {
+#ifdef RELEASE_OR_BETA
         if (asyncKind != SyncFunction) {
             error(JSMSG_ASYNC_GENERATOR);
             return null();
         }
+#endif
         generatorKind = StarGenerator;
         if (!tokenStream.getToken(&tt))
             return null();
@@ -9468,11 +9472,6 @@ Parser<ParseHandler>::propertyName(YieldHandling yieldHandling,
 
     bool isGenerator = false;
     bool isAsync = false;
-    if (ltok == TOK_MUL) {
-        isGenerator = true;
-        if (!tokenStream.getToken(&ltok))
-            return null();
-    }
 
     if (ltok == TOK_ASYNC) {
         // AsyncMethod[Yield, Await]:
@@ -9500,9 +9499,16 @@ Parser<ParseHandler>::propertyName(YieldHandling yieldHandling,
         }
     }
 
-    if (isAsync && isGenerator) {
-        error(JSMSG_ASYNC_GENERATOR);
-        return null();
+    if (ltok == TOK_MUL) {
+#ifdef RELEASE_OR_BETA
+        if (isAsync) {
+            error(JSMSG_ASYNC_GENERATOR);
+            return null();
+        }
+#endif
+        isGenerator = true;
+        if (!tokenStream.getToken(&ltok))
+            return null();
     }
 
     propAtom.set(nullptr);