/* * Copyright (c) Facebook, Inc. and its affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. */ #include @interface SelfInBlockTest : NSObject - (void)foo; @end @implementation SelfInBlockTest { int x; } - (void)foo { } - (void)mixSelfWeakSelf_bad { __weak __typeof(self) weakSelf = self; int (^my_block)() = ^() { __strong __typeof(weakSelf) strongSelf = weakSelf; if (strongSelf) { [strongSelf foo]; int x = self->x; // bug here [self foo]; } return 0; }; } - (void)strongSelfNoCheckNotWeakSelf_good { __typeof(self) weakSelf = self; int (^my_block)(BOOL) = ^(BOOL isTapped) { __strong __typeof(weakSelf) strongSelf = weakSelf; return strongSelf->x; }; } - (void)strongSelfNoCheck_bad { __weak __typeof(self) weakSelf = self; int (^my_block)(BOOL) = ^(BOOL isTapped) { __strong __typeof(weakSelf) strongSelf = weakSelf; [strongSelf foo]; return 0; }; } // very unlikely pattern, but still complies with invariant: // any use of strongSelf is bad unless checked for null beforehand - (void)strongSelfNoCheck2_bad { __weak __typeof(self) weakSelf = self; int (^my_block)() = ^() { __strong __typeof(weakSelf) strongSelf = weakSelf; __strong __typeof(weakSelf) strongSelf2 = strongSelf; return 0; }; } - (void)strongSelfCheckOnce_bad { __weak __typeof(self) weakSelf = self; int (^my_block)(BOOL) = ^(BOOL isTapped) { __strong __typeof(weakSelf) strongSelf = weakSelf; if (strongSelf) { [strongSelf foo]; int x = strongSelf->x; } else { [strongSelf foo]; } [strongSelf foo]; if (strongSelf != nil) { [strongSelf foo]; int x = strongSelf->x; } return 0; }; } - (void)strongSelfCheck2_good { __weak __typeof(self) weakSelf = self; int (^my_block)(BOOL) = ^(BOOL isTapped) { __strong __typeof(weakSelf) strongSelf = weakSelf; if (!strongSelf) { return 0; } else { [strongSelf foo]; } return 0; }; } - (void)strongSelfCheck3_bad { __weak __typeof(self) weakSelf = self; int (^my_block)(BOOL) = ^(BOOL isTapped) { __strong __typeof(weakSelf) strongSelf = weakSelf; int y = strongSelf->x; if (strongSelf == nil) { return 0; } return strongSelf->x; }; } - (void)strongSelfCheck4_good { __weak __typeof(self) weakSelf = self; int (^my_block)() = ^() { __strong __typeof(weakSelf) strongSelf = weakSelf; if (!strongSelf) { } else { } return 0; }; } @end