| // Copyright (c) 2016, 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. |
| // Test switch statement. |
| |
| // Tests some switch-case statements blocks that should and should not |
| // cause static warnings. |
| // This test is not testing runtime behavior, only static warnings. |
| |
| // None of the cases blocks should cause a warning. |
| dynamic testSwitch(int x) { |
| // Catch all control flow leaving the switch. |
| // Run switch in catch clause to check rethrow. |
| TRY: |
| try { |
| throw x; |
| } catch (x) { |
| // Add loop as break/continue target. |
| LOOP: |
| do { |
| switch (x) { |
| case 0: |
| case 1: |
| nop(x); |
| break; // Break switch. |
| case 2: |
| nop(x); |
| break LOOP; |
| case 3: |
| nop(x); |
| continue; // Continue loop. |
| case 4: |
| nop(x); |
| continue LOOP; |
| case 5: |
| nop(x); |
| continue LAST; |
| // Avoid warning for "return;"" and "return e;" in same function. |
| case 6: // //# retnon: ok |
| nop(x); // //# retnon: continued |
| return; // //# retnon: continued |
| case 7: // //# retval: ok |
| nop(x); // //# retval: continued |
| return x; // //# retval: continued |
| case 8: |
| nop(x); |
| throw x; |
| case 9: |
| nop(x); |
| rethrow; |
| case 10: |
| case 11: |
| { |
| nop(x); |
| break; // Break switch. |
| } |
| case 12: |
| { |
| nop(x); |
| break LOOP; |
| } |
| case 13: |
| { |
| nop(x); |
| continue; // Continue loop. |
| } |
| case 14: |
| { |
| nop(x); |
| continue LOOP; |
| } |
| case 15: |
| { |
| nop(x); |
| continue LAST; |
| } |
| case 16: { // //# retnon: continued |
| nop(x); // //# retnon: continued |
| return; // //# retnon: continued |
| } // //# retnon: continued |
| case 17: { // //# retval: continued |
| nop(x); // //# retval: continued |
| return x; // //# retval: continued |
| } // //# retval: continued |
| case 18: |
| { |
| nop(x); |
| throw x; |
| } |
| case 19: |
| { |
| nop(x); |
| rethrow; |
| } |
| LAST: |
| case 20: |
| { |
| nop(x); |
| // Fallthrough allowed on last statements. |
| } |
| } |
| } while (false); |
| } finally { |
| // Catch all control flow leaving the switch and ignore it. |
| // Use break instead of return to avoid warning for `return` and `return e` |
| // in same function. |
| break TRY; |
| } |
| } |
| |
| /// In Dart 2.0, all of these switch cases should cause warnings because the |
| /// fallthrough analysis was very limited and syntax-based. Null safety |
| /// includes more precise flow analysis so most of these are now valid code |
| /// because in fact no fallthrough will occur. |
| void testSwitchWarn(x) { |
| // Catch all control flow from the switch and ignore it. |
| TRY: |
| try { |
| throw 0; |
| } catch (e) { |
| // Wrap in loop as target for continue/break. |
| LOOP: |
| do { |
| switch (x) { |
| case 0: // //# 01: ok |
| case 1: { // //# 01: continued |
| { // //# 01: continued |
| nop(x); // //# 01: continued |
| break; // Break switch. // //# 01: continued |
| } // //# 01: continued |
| } // //# 01: continued |
| case 2: { // //# 02: ok |
| { // //# 02: continued |
| nop(x); // //# 02: continued |
| break LOOP; // //# 02: continued |
| } // //# 02: continued |
| } // //# 02: continued |
| case 3: { // //# 03: ok |
| { // //# 03: continued |
| nop(x); // //# 03: continued |
| continue; // Continue loop. //# 03: continued |
| } // //# 03: continued |
| } // //# 03: continued |
| case 4: { // //# 04: ok |
| { // //# 04: continued |
| nop(x); // //# 04: continued |
| continue LOOP; // //# 04: continued |
| } // //# 04: continued |
| } // //# 04: continued |
| case 5: { // //# 05: ok |
| { // //# 05: continued |
| nop(x); // //# 05: continued |
| continue LAST; // //# 05: continued |
| } // //# 05: continued |
| } // //# 05: continued |
| case 6: { // //# 06: ok |
| { // //# 06: continued |
| nop(x); // //# 06: continued |
| return; // //# 06: continued |
| } // //# 06: continued |
| } // //# 06: continued |
| case 7: { // //# 07: ok |
| { // //# 07: continued |
| nop(x); // //# 07: continued |
| return x; // //# 07: continued |
| } // //# 07: continued |
| } // //# 07: continued |
| case 8: { // //# 08: ok |
| { // //# 08: continued |
| nop(x); // //# 08: continued |
| throw x; // //# 08: continued |
| } // //# 08: continued |
| } // //# 08: continued |
| case 9: { // //# 09: ok |
| { // //# 09: continued |
| nop(x); // //# 09: continued |
| rethrow; // //# 09: continued |
| } // //# 09: continued |
| } // //# 09: continued |
| case 10: // //# 10: compile-time error |
| while (true) break; // //# 10: continued |
| case 11: // //# 11: compile-time error |
| do break; while (true); // //# 11: continued |
| case 12: // //# 12: compile-time error |
| for (;;) break; // //# 12: continued |
| case 13: // //# 13: compile-time error |
| for (var _ in []) break; // //# 13: continued |
| case 14: // //# 14: ok |
| if (x) break; else break; // //# 14: continued |
| case 15: // //# 15: ok |
| (throw 0); // //# 15: continued |
| case 16: // //# 16: compile-time error |
| nop(x); // fallthrough. // //# 16: continued |
| case 17: // //# 17: ok |
| L: break; // //# 17: continued |
| LAST: |
| case 99: |
| // Last case can't cause static warning. |
| } |
| } while (false); |
| } finally { |
| // Catch all control flow leaving the switch and ignore it. |
| // Use break instead of return to avoid warning for `return` and `return e` |
| // in same function. |
| break TRY; |
| } |
| } |
| |
| main() { |
| // Ensure that all the cases compile and run (even if they might throw). |
| for (int i = 0; i <= 20; i++) { |
| testSwitch(i); // Just make sure it runs. |
| } |
| for (int i = 0; i <= 18; i++) { |
| testSwitchWarn(i); |
| } |
| } |
| |
| /// Don't make it obvious that a switch case isn't doing anything. |
| void nop(x) {} |
