Migrate language_2/if to NNBD.

Change-Id: Ia481e2305a2a946876fc8a2dd6fd2e7c333da3fd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/148149
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>

tests/language/if/and_test.dart

@@ -0,0 +1,33 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "package:expect/expect.dart";
+
+// The "if (negative) res2 |= 3" below can be emitted as negative && (res2 |= 3)
+// in JavaScript. Dart2js produced the wrong output.
+
+_shiftRight(x, y) => x;
+int64_bits(x) => x;
+
+class A {
+  opshr(int n, a2) {
+    int res2;
+    bool negative = a2 == 496;
+
+    res2 = _shiftRight(a2, n);
+    if (negative) {
+      res2 |= 3;
+    }
+    return int64_bits(res2);
+  }
+}
+
+main() {
+  var a = new A();
+  var t;
+  for (int i = 0; i < 3; i++) {
+    t = a.opshr(99, 496);
+  }
+  Expect.equals(499, t);
+}

tests/language/if/dangling_else_test.dart

@@ -0,0 +1,84 @@
+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Tests dangling else. The VM should not have any problems, but dart2js or
+// dart2dart could get this wrong.
+
+import "package:expect/expect.dart";
+
+nestedIf1(notTrue) {
+  if (notTrue) return 'bad input';
+  if (notTrue) {
+    if (notTrue) {
+      return 'bad';
+    }
+  } else {
+    return 'good';
+  }
+  return 'bug';
+}
+
+nestedIf2(notTrue) {
+  if (notTrue) return 'bad input';
+  if (notTrue) {
+    if (notTrue) {
+      return 'bad';
+    } else {
+      if (notTrue) {
+        return 'bad';
+      }
+    }
+  } else {
+    return 'good';
+  }
+  return 'bug';
+}
+
+nestedWhile(notTrue) {
+  if (notTrue) return 'bad input';
+  if (notTrue) {
+    while (notTrue) {
+      if (notTrue) {
+        return 'bad';
+      }
+    }
+  } else {
+    return 'good';
+  }
+  return 'bug';
+}
+
+nestedFor(notTrue) {
+  if (notTrue) return 'bad input';
+  if (notTrue) {
+    for (int i = 0; i < 3; i++) {
+      if (i == 0) {
+        return 'bad';
+      }
+    }
+  } else {
+    return 'good';
+  }
+  return 'bug';
+}
+
+nestedLabeledStatement(notTrue) {
+  if (notTrue) return 'bad input';
+  if (notTrue) {
+    label:
+    if (notTrue) {
+      break label;
+    }
+  } else {
+    return 'good';
+  }
+  return 'bug';
+}
+
+main() {
+  Expect.equals('good', nestedIf1(false));
+  Expect.equals('good', nestedIf2(false));
+  Expect.equals('good', nestedWhile(false));
+  Expect.equals('good', nestedFor(false));
+  Expect.equals('good', nestedLabeledStatement(false));
+}

tests/language/if/if_test.dart

@@ -0,0 +1,95 @@
+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Dart test program for testing if statement.
+
+import "package:expect/expect.dart";
+
+class Helper {
+  static int f0(bool b) {
+    if (b) ;
+    if (b)
+      ;
+    else
+      ;
+    if (b) {}
+    if (b) {} else {}
+    return 0;
+  }
+
+  static int f1(bool b) {
+    if (b)
+      return 1;
+    else
+      return 2;
+  }
+
+  static int f2(bool b) {
+    if (b) {
+      return 1;
+    } else {
+      return 2;
+    }
+  }
+
+  static int f3(bool b) {
+    if (b) return 1;
+    return 2;
+  }
+
+  static int f4(bool b) {
+    if (b) {
+      return 1;
+    }
+    return 2;
+  }
+
+  static int f5(bool b) {
+    if (!b) {
+      return 1;
+    }
+    return 2;
+  }
+
+  static int f6(bool a, bool b) {
+    if (a || b) {
+      return 1;
+    }
+    return 2;
+  }
+
+  static int f7(bool a, bool b) {
+    if (a && b) {
+      return 1;
+    }
+    return 2;
+  }
+}
+
+class IfTest {
+  static testMain() {
+    Expect.equals(0, Helper.f0(true));
+    Expect.equals(1, Helper.f1(true));
+    Expect.equals(2, Helper.f1(false));
+    Expect.equals(1, Helper.f2(true));
+    Expect.equals(2, Helper.f2(false));
+    Expect.equals(1, Helper.f3(true));
+    Expect.equals(2, Helper.f3(false));
+    Expect.equals(1, Helper.f4(true));
+    Expect.equals(2, Helper.f4(false));
+    Expect.equals(2, Helper.f5(true));
+    Expect.equals(1, Helper.f5(false));
+    Expect.equals(1, Helper.f6(true, true));
+    Expect.equals(1, Helper.f6(true, false));
+    Expect.equals(1, Helper.f6(false, true));
+    Expect.equals(2, Helper.f6(false, false));
+    Expect.equals(1, Helper.f7(true, true));
+    Expect.equals(2, Helper.f7(true, false));
+    Expect.equals(2, Helper.f7(false, true));
+    Expect.equals(2, Helper.f7(false, false));
+  }
+}
+
+main() {
+  IfTest.testMain();
+}

tests/language/if/nested_if_test.dart

@@ -0,0 +1,35 @@
+// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Dart2Js had problems with nested ifs inside loops.
+
+import "package:expect/expect.dart";
+
+foo(x, a) {
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*------- Avoid inlining ----------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  /*---------------------------------------------*/
+  for (int i = 0; i < 10; i++) {
+    if (x) {
+      if (!x) a = [];
+      a.add(3);
+    }
+  }
+  return a;
+}
+
+main() {
+  var a = foo(true, []);
+  Expect.equals(10, a.length);
+  Expect.equals(3, a[0]);
+}