[Merge chakra-core/ChakraCore@0c739a73be] [1.6>1.7] [MERGE #3445 @ane…

…eshdk] Keep the same register allocation path for debug and non-debug mode in generators

Merge pull request #3445 from aneeshdk:GeneratorDynamicAttach

In debug mode we have different register allocation logic for inner scope slots. In case of generators if the debugger is attached dynamically before the generator completes then this can cause issues. Current fix is to avoid the different paths for register allocation.

deps/chakrashim/core/lib/Runtime/ByteCode/ByteCodeEmitter.cpp

@@ -1744,9 +1744,13 @@ void ByteCodeGenerator::FinalizeRegisters(FuncInfo * funcInfo, Js::FunctionBody
 
     this->SetClosureRegisters(funcInfo, byteCodeFunction);
 
-    if (this->IsInDebugMode())
+    if (this->IsInDebugMode() || byteCodeFunction->IsCoroutine())
     {
         // Give permanent registers to the inner scopes in debug mode.
+        // TODO: We create seperate debuggerscopes for each block which has own scope. These are stored in the var registers
+        // allocated below. Ideally we should change this logic to not allocate separate registers for these and save the debug
+        // info in corresponding symbols and use it from there. This will also affect the temp register allocation logic in
+        // EmitOneFunction.
         uint innerScopeCount = funcInfo->InnerScopeCount();
         byteCodeFunction->SetInnerScopeCount(innerScopeCount);
         if (innerScopeCount)
@@ -3181,8 +3185,9 @@ void ByteCodeGenerator::EmitOneFunction(ParseNode *pnode)
 
         // Reserve temp registers for the inner scopes. We prefer temps because the JIT will then renumber them
         // and see different lifetimes. (Note that debug mode requires permanent registers. See FinalizeRegisters.)
+        // Need to revisit the condition when enabling JitES6Generators.
         uint innerScopeCount = funcInfo->InnerScopeCount();
-        if (!this->IsInDebugMode())
+        if (!this->IsInDebugMode() && !byteCodeFunction->IsCoroutine())
         {
             byteCodeFunction->SetInnerScopeCount(innerScopeCount);
             if (innerScopeCount)

deps/chakrashim/core/test/DebuggerCommon/AsyncDynamicAttach.js

@@ -0,0 +1,22 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+function attach(f) {
+  (function (r) {
+    WScript.Attach(r);
+  })(f);
+}
+
+async function mainTest(notAttachCall) {
+    if (notAttachCall) {
+        for (let i = 0; i < 1; ++i) {
+            await attach(mainTest);
+        }
+    } else {
+        var i = 10;/**bp:locals()**/
+    }
+}
+mainTest(true);
+WScript.Echo("PASSED");

deps/chakrashim/core/test/DebuggerCommon/AsyncDynamicAttach.js.dbg.baseline

@@ -0,0 +1,10 @@
+[
+  {
+    "this": "Object {...}",
+    "arguments": "Object {...}",
+    "locals": {
+      "notAttachCall": "undefined undefined",
+      "i": "undefined undefined"
+    }
+  }
+]

deps/chakrashim/core/test/DebuggerCommon/rlexe.xml

@@ -1356,4 +1356,11 @@
       <compile-flags>-debuglaunch -dbgbaseline:promisedisplay.js.dbg.baseline</compile-flags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>AsyncDynamicAttach.js</files>
+      <compile-flags>-dbgbaseline:AsyncDynamicAttach.js.dbg.baseline</compile-flags>
+      <tags>exclude_dynapogo</tags>
+    </default>
+  </test>
 </regress-exe>