Add tests that exercise GetClosureScope

Summary:
We currently have no tests that emit GetClosureScope, since we can
almost always determine the environment of a function being inlined.

Add a simple test that produces it.

Reviewed By: avp

Differential Revision: D66236885

fbshipit-source-id: b0e62e8ea1a394fb0f2c676fc51fbf33b0b0a04f

test/Optimizer/inline-unavailable-env.js

@@ -0,0 +1,82 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// RUN: %hermesc -dump-ir %s | %FileCheckOrRegen --match-full-lines %s
+
+// Test our ability to inline functions where their enclosing environment is not
+// available at the call site.
+
+function foo(sink){
+  let x;
+  let numBar = 0;
+  function bar() {
+    let y = ++numBar;
+    // Assign x in bar, so the parent environment of the function is unavailable
+    // when  we call x, and we are forced to get the environment from the
+    // closure.
+    x = function () { "inline"; return ++y; };
+  }
+  sink(bar);
+  return x();
+}
+
+// Auto-generated content below. Please do not modify manually.
+
+// CHECK:scope %VS0 []
+
+// CHECK:function global(): undefined
+// CHECK-NEXT:%BB0:
+// CHECK-NEXT:  %0 = CreateScopeInst (:environment) %VS0: any, empty: any
+// CHECK-NEXT:       DeclareGlobalVarInst "foo": string
+// CHECK-NEXT:  %2 = CreateFunctionInst (:object) %0: environment, %foo(): functionCode
+// CHECK-NEXT:       StorePropertyLooseInst %2: object, globalObject: object, "foo": string
+// CHECK-NEXT:       ReturnInst undefined: undefined
+// CHECK-NEXT:function_end
+
+// CHECK:scope %VS1 [x: undefined|object, numBar: number]
+
+// CHECK:scope %VS2 [y: number]
+
+// CHECK:function foo(sink: any): number
+// CHECK-NEXT:%BB0:
+// CHECK-NEXT:  %0 = GetParentScopeInst (:environment) %VS0: any, %parentScope: environment
+// CHECK-NEXT:  %1 = CreateScopeInst (:environment) %VS1: any, %0: environment
+// CHECK-NEXT:  %2 = LoadParamInst (:any) %sink: any
+// CHECK-NEXT:  %3 = CreateFunctionInst (:object) %1: environment, %bar(): functionCode
+// CHECK-NEXT:       StoreFrameInst %1: environment, undefined: undefined, [%VS1.x]: undefined|object
+// CHECK-NEXT:       StoreFrameInst %1: environment, 0: number, [%VS1.numBar]: number
+// CHECK-NEXT:  %6 = CallInst (:any) %2: any, empty: any, false: boolean, empty: any, undefined: undefined, undefined: undefined, %3: object
+// CHECK-NEXT:  %7 = LoadFrameInst (:undefined|object) %1: environment, [%VS1.x]: undefined|object
+// CHECK-NEXT:  %8 = TypeOfIsInst (:boolean) %7: undefined|object, typeOfIs(Function)
+// CHECK-NEXT:       CondBranchInst %8: boolean, %BB2, %BB1
+// CHECK-NEXT:%BB1:
+// CHECK-NEXT:        ThrowTypeErrorInst "Trying to call a non-function": string
+// CHECK-NEXT:%BB2:
+// CHECK-NEXT:  %11 = GetClosureScopeInst (:environment) %VS2: any, %7: undefined|object
+// CHECK-NEXT:  %12 = LoadFrameInst (:number) %11: environment, [%VS2.y]: number
+// CHECK-NEXT:  %13 = FAddInst (:number) %12: number, 1: number
+// CHECK-NEXT:        StoreFrameInst %11: environment, %13: number, [%VS2.y]: number
+// CHECK-NEXT:        ReturnInst %13: number
+// CHECK-NEXT:function_end
+
+// CHECK:function bar(): undefined
+// CHECK-NEXT:%BB0:
+// CHECK-NEXT:  %0 = GetParentScopeInst (:environment) %VS1: any, %parentScope: environment
+// CHECK-NEXT:  %1 = CreateScopeInst (:environment) %VS2: any, %0: environment
+// CHECK-NEXT:  %2 = LoadFrameInst (:number) %0: environment, [%VS1.numBar]: number
+// CHECK-NEXT:  %3 = FAddInst (:number) %2: number, 1: number
+// CHECK-NEXT:       StoreFrameInst %0: environment, %3: number, [%VS1.numBar]: number
+// CHECK-NEXT:       StoreFrameInst %1: environment, %3: number, [%VS2.y]: number
+// CHECK-NEXT:  %6 = CreateFunctionInst (:object) %1: environment, %x(): functionCode
+// CHECK-NEXT:       StoreFrameInst %0: environment, %6: object, [%VS1.x]: undefined|object
+// CHECK-NEXT:       ReturnInst undefined: undefined
+// CHECK-NEXT:function_end
+
+// CHECK:function x(): number [allCallsitesKnownInStrictMode,unreachable]
+// CHECK-NEXT:%BB0:
+// CHECK-NEXT:       UnreachableInst
+// CHECK-NEXT:function_end

test/hermes/inline-unavailable-env.js

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// RUN: %hermes %s | %FileCheck --match-full-lines %s
+// RUN: %shermes -exec %s | %FileCheck --match-full-lines %s
+
+// Test our ability to inline functions where their enclosing environment is not
+// available at the call site.
+
+function foo(sink){
+    let x;
+    let numBar = 0;
+    function bar() {
+        let y = ++numBar;
+        // Assign x in bar, so the parent environment of the function is unavailable
+        // when  we call x, and we are forced to get the environment from the
+        // closure.
+        x = function () { "inline"; return ++y; };
+    }
+    sink(bar);
+    return x();
+}
+
+// Call bar when it is passed in, and then print the result.
+print(foo((cb) => { cb(); cb(); cb(); }));
+// CHECK: 4