binder: don't inline generator function's control flow

Fixes: #23565

src/compiler/binder.ts

@@ -516,8 +516,9 @@ namespace ts {
                 const saveReturnTarget = currentReturnTarget;
                 const saveActiveLabels = activeLabels;
                 const saveHasExplicitReturn = hasExplicitReturn;
-                const isIIFE = containerFlags & ContainerFlags.IsFunctionExpression && !hasModifier(node, ModifierFlags.Async) && !!getImmediatelyInvokedFunctionExpression(node);
-                // A non-async IIFE is considered part of the containing control flow. Return statements behave
+                const isIIFE = containerFlags & ContainerFlags.IsFunctionExpression && !hasModifier(node, ModifierFlags.Async) &&
+                    !(<FunctionLikeDeclaration>node).asteriskToken && !!getImmediatelyInvokedFunctionExpression(node);
+                // A non-async, non-generator IIFE is considered part of the containing control flow. Return statements behave
                 // similarly to break statements that exit to a label just past the statement body.
                 if (!isIIFE) {
                     currentFlow = { flags: FlowFlags.Start };

tests/baselines/reference/controlFlowIIFE.errors.txt

@@ -0,0 +1,89 @@
+error TS2318: Cannot find global type 'IterableIterator'.
+error TS2468: Cannot find global value 'Promise'.
+tests/cases/conformance/controlFlow/controlFlowIIFE.ts(64,5): error TS2454: Variable 'v' is used before being assigned.
+tests/cases/conformance/controlFlow/controlFlowIIFE.ts(69,6): error TS2705: An async function or method in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your `--lib` option.
+tests/cases/conformance/controlFlow/controlFlowIIFE.ts(72,5): error TS2454: Variable 'v' is used before being assigned.
+
+
+!!! error TS2318: Cannot find global type 'IterableIterator'.
+!!! error TS2468: Cannot find global value 'Promise'.
+==== tests/cases/conformance/controlFlow/controlFlowIIFE.ts (3 errors) ====
+    declare function getStringOrNumber(): string | number;
+    
+    function f1() {
+        let x = getStringOrNumber();
+        if (typeof x === "string") {
+            let n = function() {
+                return x.length;
+            }();
+        }
+    }
+    
+    function f2() {
+        let x = getStringOrNumber();
+        if (typeof x === "string") {
+            let n = (function() {
+                return x.length;
+            })();
+        }
+    }
+    
+    function f3() {
+        let x = getStringOrNumber();
+        let y: number;
+        if (typeof x === "string") {
+            let n = (z => x.length + y + z)(y = 1);
+        }
+    }
+    
+    // Repros from #8381
+    
+    let maybeNumber: number | undefined;
+    (function () {
+        maybeNumber = 1;
+    })();
+    maybeNumber++;
+    if (maybeNumber !== undefined) {
+        maybeNumber++;
+    }
+    
+    let test: string | undefined;
+    if (!test) {
+        throw new Error('Test is not defined');
+    }
+    (() => {
+        test.slice(1); // No error
+    })();
+    
+    // Repro from #23565
+    
+    function f4() {
+        let v: number;
+        (function() {
+            v = 1;
+        })();
+        v;
+    }
+    
+    function f5() {
+        let v: number;
+        (function*() {
+            yield 1;
+            v = 1;
+        })();
+        v; // still undefined
+        ~
+!!! error TS2454: Variable 'v' is used before being assigned.
+    }
+    
+    function f6() {
+        let v: number;
+        (async function() {
+         ~~~~~
+!!! error TS2705: An async function or method in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your `--lib` option.
+            v = await 1;
+        })();
+        v; // still undefined
+        ~
+!!! error TS2454: Variable 'v' is used before being assigned.
+    }

tests/baselines/reference/controlFlowIIFE.js

@@ -44,9 +44,71 @@ if (!test) {
 }
 (() => {
     test.slice(1); // No error
-})();
+})();
+
+// Repro from #23565
+
+function f4() {
+    let v: number;
+    (function() {
+        v = 1;
+    })();
+    v;
+}
+
+function f5() {
+    let v: number;
+    (function*() {
+        yield 1;
+        v = 1;
+    })();
+    v; // still undefined
+}
+
+function f6() {
+    let v: number;
+    (async function() {
+        v = await 1;
+    })();
+    v; // still undefined
+}
 
 //// [controlFlowIIFE.js]
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [0, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+};
 function f1() {
     var x = getStringOrNumber();
     if (typeof x === "string") {
@@ -86,3 +148,42 @@ if (!test) {
 (function () {
     test.slice(1); // No error
 })();
+// Repro from #23565
+function f4() {
+    var v;
+    (function () {
+        v = 1;
+    })();
+    v;
+}
+function f5() {
+    var v;
+    (function () {
+        return __generator(this, function (_a) {
+            switch (_a.label) {
+                case 0: return [4 /*yield*/, 1];
+                case 1:
+                    _a.sent();
+                    v = 1;
+                    return [2 /*return*/];
+            }
+        });
+    })();
+    v; // still undefined
+}
+function f6() {
+    var v;
+    (function () {
+        return __awaiter(this, void 0, void 0, function () {
+            return __generator(this, function (_a) {
+                switch (_a.label) {
+                    case 0: return [4 /*yield*/, 1];
+                    case 1:
+                        v = _a.sent();
+                        return [2 /*return*/];
+                }
+            });
+        });
+    })();
+    v; // still undefined
+}

tests/baselines/reference/controlFlowIIFE.symbols

@@ -108,3 +108,51 @@ if (!test) {
 >slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
 
 })();
+
+// Repro from #23565
+
+function f4() {
+>f4 : Symbol(f4, Decl(controlFlowIIFE.ts, 45, 5))
+
+    let v: number;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 50, 7))
+
+    (function() {
+        v = 1;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 50, 7))
+
+    })();
+    v;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 50, 7))
+}
+
+function f5() {
+>f5 : Symbol(f5, Decl(controlFlowIIFE.ts, 55, 1))
+
+    let v: number;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 58, 7))
+
+    (function*() {
+        yield 1;
+        v = 1;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 58, 7))
+
+    })();
+    v; // still undefined
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 58, 7))
+}
+
+function f6() {
+>f6 : Symbol(f6, Decl(controlFlowIIFE.ts, 64, 1))
+
+    let v: number;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 67, 7))
+
+    (async function() {
+        v = await 1;
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 67, 7))
+
+    })();
+    v; // still undefined
+>v : Symbol(v, Decl(controlFlowIIFE.ts, 67, 7))
+}

tests/baselines/reference/controlFlowIIFE.types

@@ -150,3 +150,73 @@ if (!test) {
 >1 : 1
 
 })();
+
+// Repro from #23565
+
+function f4() {
+>f4 : () => void
+
+    let v: number;
+>v : number
+
+    (function() {
+>(function() {        v = 1;    })() : void
+>(function() {        v = 1;    }) : () => void
+>function() {        v = 1;    } : () => void
+
+        v = 1;
+>v = 1 : 1
+>v : number
+>1 : 1
+
+    })();
+    v;
+>v : number
+}
+
+function f5() {
+>f5 : () => void
+
+    let v: number;
+>v : number
+
+    (function*() {
+>(function*() {        yield 1;        v = 1;    })() : {}
+>(function*() {        yield 1;        v = 1;    }) : () => {}
+>function*() {        yield 1;        v = 1;    } : () => {}
+
+        yield 1;
+>yield 1 : any
+>1 : 1
+
+        v = 1;
+>v = 1 : 1
+>v : number
+>1 : 1
+
+    })();
+    v; // still undefined
+>v : number
+}
+
+function f6() {
+>f6 : () => void
+
+    let v: number;
+>v : number
+
+    (async function() {
+>(async function() {        v = await 1;    })() : Promise<void>
+>(async function() {        v = await 1;    }) : () => Promise<void>
+>async function() {        v = await 1;    } : () => Promise<void>
+
+        v = await 1;
+>v = await 1 : 1
+>v : number
+>await 1 : 1
+>1 : 1
+
+    })();
+    v; // still undefined
+>v : number
+}

tests/cases/conformance/controlFlow/controlFlowIIFE.ts

@@ -45,4 +45,31 @@ if (!test) {
 }
 (() => {
     test.slice(1); // No error
-})();
+})();
+
+// Repro from #23565
+
+function f4() {
+    let v: number;
+    (function() {
+        v = 1;
+    })();
+    v;
+}
+
+function f5() {
+    let v: number;
+    (function*() {
+        yield 1;
+        v = 1;
+    })();
+    v; // still undefined
+}
+
+function f6() {
+    let v: number;
+    (async function() {
+        v = await 1;
+    })();
+    v; // still undefined
+}