readability-else-after-return¶
LLVM Coding Standards advises to
reduce indentation where possible and where it makes understanding code easier.
Early exit is one of the suggested enforcements of that. Please do not use
else or else if after something that interrupts control flow - like
return, break, continue, throw.
The following piece of code illustrates how the check works. This piece of code:
void foo(int Value) {
  int Local = 0;
  for (int i = 0; i < 42; i++) {
    if (Value == 1) {
      return;
    } else {
      Local++;
    }
    if (Value == 2)
      continue;
    else
      Local++;
    if (Value == 3) {
      throw 42;
    } else {
      Local++;
    }
  }
}
Would be transformed into:
void foo(int Value) {
  int Local = 0;
  for (int i = 0; i < 42; i++) {
    if (Value == 1) {
      return;
    }
    Local++;
    if (Value == 2)
      continue;
    Local++;
    if (Value == 3) {
      throw 42;
    }
    Local++;
  }
}
Options¶
- WarnOnUnfixable¶
- When true, emit a warning for cases where the check can’t output a Fix-It. These can occur with declarations inside the - elsebranch that would have an extended lifetime if the- elsebranch was removed. Default value is true.
- WarnOnConditionVariables¶
- When true, the check will attempt to refactor a variable defined inside the condition of the - ifstatement that is used in the- elsebranch defining them just before the- ifstatement. This can only be done if the- ifstatement is the last statement in its parent’s scope. Default value is true.
LLVM alias¶
There is an alias of this check called llvm-else-after-return.
In that version the options WarnOnUnfixable and
WarnOnConditionVariables are both set to false by default.
This check helps to enforce this LLVM Coding Standards recommendation.