Fix range-analysis.

tests/language/range_analysis3_test.dart

+// Copyright (c) 2014, 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";
+
+confuse(x) {
+  if (new DateTime.now().millisecondsSinceEpoch == 0) {
+    return confuse(x + 1);
+  } else if (new DateTime.now().millisecondsSinceEpoch == 0) {
+    return confuse(x - 1);
+  }
+  return x;
+}
+
+test1() {
+  int x = 0;
+  // Give x a range of -1 to 0.
+  if (confuse(0) == 1) x = -1;
+
+  int y = 0;
+  // Give y a range of 0 to 1.
+  if (confuse(0) == 1) y = 1;
+
+  var zero = 0;
+
+  var status = "bad";
+  if (x < zero) {
+    Expect.fail("unreachable");
+  } else {
+    // Dart2js must not conclude that zero has a range of [-1, 0].
+    if (y <= zero) {
+      status = "good";
+    }
+  }
+  Expect.equals("good", status);
+}
+
+test2() {
+  int x = 0;
+  // Give x a range of -1 to 0.
+  if (confuse(0) == 1) x = -1;
+
+  int y = 0;
+  // Give y a range of -1 to 1.
+  if (confuse(0) == 1) y = 1;
+  if (confuse(1) == 2) y = -1;
+
+  var status = "good";
+  if (x < y) {
+    Expect.fail("unreachable");
+  } else {
+    // Dart2js must not conclude that y has a range of [-1, -1].
+    if (y == -1) {
+      status = "bad";
+    }
+  }
+  Expect.equals("good", status);
+}
+
+test3a() {
+  int x = 0;
+  // Give x a range of -1 to 1.
+  if (confuse(0) == 1) x = -1;
+  if (confuse(1) == 2) x = 1;
+
+  int y = 0;
+  // Give y a range of -1 to 1.
+  if (confuse(0) == 1) y = 1;
+  if (confuse(1) == 2) y = -1;
+
+  var status = "good";
+  if (x < y) {
+    Expect.fail("unreachable");
+  } else {
+    // Test that the range-analysis does not lose a value.
+    if (x <= -1) status = "bad";
+    if (x >= 1) status = "bad";
+    if (x < 0) status = "bad";
+    if (x > 0) status = "bad";
+    if (-1 >= x) status = "bad";
+    if (1 <= x) status = "bad";
+    if (0 > x) status = "bad";
+    if (0 < x) status = "bad";
+    if (y <= -1) status = "bad";
+    if (y >= 1) status = "bad";
+    if (y < 0) status = "bad";
+    if (y > 0) status = "bad";
+    if (-1 >= y) status = "bad";
+    if (1 <= y) status = "bad";
+    if (0 > y) status = "bad";
+    if (0 < y) status = "bad";
+  }
+  Expect.equals("good", status);
+}
+
+test3b() {
+  int x = 0;
+  // Give x a range of -2 to 0.
+  if (confuse(0) == 1) x = -2;
+
+  int y = 0;
+  // Give y a range of -1 to 1.
+  if (confuse(0) == 1) y = 1;
+  if (confuse(1) == 2) y = -1;
+
+  var status = "good";
+  if (x < y) {
+    Expect.fail("unreachable");
+  } else {
+    // Test that the range-analysis does not lose a value.
+    if (x <= -1) status = "bad";
+    if (x >= 1) status = "bad";
+    if (x < 0) status = "bad";
+    if (x > 0) status = "bad";
+    if (-1 >= x) status = "bad";
+    if (1 <= x) status = "bad";
+    if (0 > x) status = "bad";
+    if (0 < x) status = "bad";
+    if (y <= -1) status = "bad";
+    if (y >= 1) status = "bad";
+    if (y < 0) status = "bad";
+    if (y > 0) status = "bad";
+    if (-1 >= y) status = "bad";
+    if (1 <= y) status = "bad";
+    if (0 > y) status = "bad";
+    if (0 < y) status = "bad";
+  }
+  Expect.equals("good", status);
+}
+
+test4a() {
+  int x = -1;
+  // Give x a range of -1 to 1.
+  if (confuse(0) == 1) x = 1;
+
+  int y = 0;
+  // Give y a range of -1 to 1.
+  if (confuse(0) == 1) y = 1;
+  if (confuse(1) == 2) y = -1;
+
+  var status = "good";
+  if (x < y) {
+    // Test that the range-analysis does not lose a value.
+    if (x <= -2) status = "bad";
+    if (x >= 0) status = "bad";
+    if (x < -1) status = "bad";
+    if (x > -1) status = "bad";
+    if (-2 >= x) status = "bad";
+    if (0 <= x) status = "bad";
+    if (-1 > x) status = "bad";
+    if (-1 < x) status = "bad";
+    if (y <= -1) status = "bad";
+    if (y >= 1) status = "bad";
+    if (y < 0) status = "bad";
+    if (y > 0) status = "bad";
+    if (-1 >= y) status = "bad";
+    if (1 <= y) status = "bad";
+    if (0 > y) status = "bad";
+    if (0 < y) status = "bad";
+  } else {
+    Expect.fail("unreachable");
+  }
+  Expect.equals("good", status);
+}
+
+test4b() {
+  int x = -1;
+  // Give x a range of -2 to 0.
+  if (confuse(0) == 1) x = -2;
+  if (confuse(1) == 2) x = 0;
+
+  int y = 0;
+  // Give y a range of -1 to 1.
+  if (confuse(0) == 1) y = 1;
+  if (confuse(1) == 2) y = -1;
+
+  var status = "good";
+  if (x < y) {
+    // Test that the range-analysis does not lose a value.
+    if (x <= -2) status = "bad";
+    if (x >= 0) status = "bad";
+    if (x < -1) status = "bad";
+    if (x > -1) status = "bad";
+    if (-2 >= x) status = "bad";
+    if (0 <= x) status = "bad";
+    if (-1 > x) status = "bad";
+    if (-1 < x) status = "bad";
+    if (y <= -1) status = "bad";
+    if (y >= 1) status = "bad";
+    if (y < 0) status = "bad";
+    if (y > 0) status = "bad";
+    if (-1 >= y) status = "bad";
+    if (1 <= y) status = "bad";
+    if (0 > y) status = "bad";
+    if (0 < y) status = "bad";
+  } else {
+    Expect.fail("unreachable");
+  }
+  Expect.equals("good", status);
+}
+
+main() {
+  test1();
+  test2();
+  test3a();
+  test3b();
+  test4a();
+  test4b();
+}