* Add check for return value of boolean function
The rule for converting an integer to a boolean is that 0 is mapped to
false and everything else is mapped to true. There is nothing wrong with
the following code (according to the standards):
bool f()
{
return -1;
}
and neither gcc nor clang will warn about it. However, it's a bit
confusing. This commit adds a check that warns when a value other than 0
or 1 is returned from a boolean function (similar to the existing check
that functions with boolean arguments are only passed 0 or 1). Since the
code is perfectly legal, set the severity to "Style".
* Use early continue and remove some braces
* Add testcase with multiple returns
* Avoid null pointer dereference in case of return without operand
* Skip lambdas
Add TODO-test cases that shows FPs when the return type of lambdas are
specified explicitly (this is a problem with findLambdaEndToken).
* Enable testcases
869e4ba6ab