[PATCH] D71510: [clang][checkers] Added new checker 'error-return-checker'.

[Balázs Kéri via Phabricator via cfe-commits]

balazske added a comment.

I wanted to implement the rules described here:
https://wiki.sei.cmu.edu/confluence/display/c/ERR33-C.+Detect+and+handle+standard+library+errors
This lists the functions to check so this knowledge has to be built into the checker and there are examples of this in other checkers (stream or memory or string functions for example). The functions have different kinds conditions on the return value in case of error. It is not sufficient to simply check that the return value is assigned to something or used because it may be used without check for error. So I tried to do something that can find if exactly a check for the error condition was made. (Still it is not perfect because the value can be used before the error checking.)
The cast to `void` is the special way to avoid the warning, in every other case the return value has to be checked for error or there is an exception that should be documented (if the function "can not fail" or the error does not matter). This may be too much warnings for a normal project but acceptable if extra safe code is needed. If we want to have that clang SA can (at least partially) check for that rule "ERR33-C" this (or similar) check is needed.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D71510/new/

https://reviews.llvm.org/D71510