OpCode for Finally inside Generator or Async function

Was not implemented in the JIT, resulting in Abort when jitting a Generator or async function (or a loop inside a generator or async function) that contained a finally block.

Note the for...of construction includes an implicit finally block hence triggered this error.

Add handling in FlowGraph and Lowerer as well as simple test case.

Author: rhuanjl

lib/Backend/FlowGraph.cpp

@@ -1,5 +1,6 @@
 //-------------------------------------------------------------------------------------------------------
 // Copyright (C) Microsoft. All rights reserved.
+// Copyright (c) ChakraCore Project Contributors. All rights reserved.
 // Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
 //-------------------------------------------------------------------------------------------------------
 #include "Backend.h"
@@ -339,6 +340,7 @@ FlowGraph::Build(void)
             break;
 
         case Js::OpCode::TryFinally:
+        case Js::OpCode::TryFinallyWithYield:
             if (this->finallyLabelStack)
             {
                 AssertOrFailFast(!this->finallyLabelStack->Empty());
@@ -1778,6 +1780,7 @@ FlowGraph::Destroy(void)
                     {
                     case Js::OpCode::TryCatch:
                     case Js::OpCode::TryFinally:
+                    case Js::OpCode::TryFinallyWithYield:
                         AssertMsg(region->GetParent() == predRegion, "Bad region prop on entry to try-catch/finally");
                         if (intermediateBlock->GetFirstInstr() == predBlock->GetLastInstr()->AsBranchInstr()->GetTarget())
                         {
@@ -2036,6 +2039,7 @@ FlowGraph::PropagateRegionFromPred(BasicBlock * block, BasicBlock * predBlock, R
             break;
 
         case Js::OpCode::TryFinally:
+        case Js::OpCode::TryFinallyWithYield:
             // Entry to a try-finally. See whether we're entering the try or the finally
             // by looking for the handler label.
             Assert(predLastInstr->m_next->IsLabelInstr());

lib/Backend/Lower.cpp

@@ -2605,6 +2605,8 @@ Lowerer::LowerRange(IR::Instr *instrStart, IR::Instr *instrEnd, bool defaultDoFa
             instrPrev = this->LowerTry(instr, true /*try-catch*/);
             break;
 
+        case Js::OpCode::TryFinallyWithYield:
+            instr->m_opcode = Js::OpCode::TryFinally;
         case Js::OpCode::TryFinally:
             instrPrev = this->LowerTry(instr, false /*try-finally*/);
             break;

test/es6GeneratorJit/async-jit-bugs.js

@@ -4,7 +4,7 @@
 // Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
 //-------------------------------------------------------------------------------------------------------
 
-function main() {
+function testOne() {
     const v2 = [13.37,13.37,13.37,13.37,13.37];
     async function v4(v5,v6,v7,v8) {
         const v10 = 0;
@@ -26,8 +26,68 @@ function main() {
             const v38 = --v33;
         }
         const v39 = 128;
-        print("pass")
     }
-v4("vEBD7ei78q");
+    return v4("vEBD7ei78q");
 }
-main();
+
+function testTwo() {
+    let finallyCount = 0;
+    let throwCount = 0;
+    async function asyncFinally() {
+        for (let i = 0; i < 1000; ++i){
+            try {
+                if (i > 170) {
+                    ++throwCount;
+                    throw 1;
+                }
+            }
+            finally {
+                ++finallyCount;
+            }
+        }
+    }
+    return asyncFinally ().catch((e) => {
+        if (throwCount != 1) {
+            throw new Error ("Wrong number of throws within async function expected 1 but received " + throwCount);
+        }
+        if (e != 1) {
+            throw new Error ("Wrong value thrown from async function expected 1 but received " + e);
+        }
+        if (finallyCount != 172) {
+            throw new Error ("Wrong number of finally calls from async function expected 172 but received " + finallyCount);
+        }
+    });
+}
+
+function testThree() {
+    let finallyCount = 0;
+    let throwCount = 0;
+    async function asyncFinallyAwait() {
+        for (let i = 0; i < 1000; ++i){
+            try {
+                if (i > 170) {
+                    ++throwCount;
+                    throw 1;
+                }
+            }
+            finally {
+                await 5;
+                ++finallyCount;
+            }
+        }
+    }
+    return asyncFinallyAwait().catch((e) => {
+        if (throwCount != 1) {
+            throw new Error ("Wrong number of throws within async function expected 1 but received " + throwCount);
+        }
+        if (e != 1) {
+            throw new Error ("Wrong value thrown from async function expected 1 but received " + e);
+        }
+        if (finallyCount != 172) {
+            throw new Error ("Wrong number of finally calls from async function expected 172 but received " + finallyCount);
+        }
+    });
+}
+
+
+Promise.all([testOne(), testTwo(), testThree()]).then(()=>{print("pass")}, (e)=>{print (e)});