Defining a block in a switch statement results in a compiler error

Question

Consider the following switch statement:

switch (buttonIndex) {     case 0:         [self fooWithCompletion:^{             [weakSelf finishEditing];         }];         break;     case 1: // Error here         [self barWithCompletion:^{             [weakSelf finishEditing];         }];         break;         default:         break; } 

It causes the compiler error

Cannot jump from switch statement to this case label

on the line case 1:.

Why is this happening and how do I fix it?

Answer 1

The block definition creates a new scope which seems to interfere with the compiler's ability to correctly interpret the switch statement.

Adding scope delimiters for each case label resolves the error. I think this is because the block's scope is now unambiguously a child of the case scope.

switch (buttonIndex) {     case 0:     {         [self updateUserDataWithCompletion:^{             [weakSelf finishEditing];         }];         break;     }     case 1:     {         [self updateOtherDataWithCompletion:^{             [weakSelf finishEditing];         }];         break;     }     default:         break; } 

There's a bug open with LLVM for a similar issue.