Safer C programming

TL;DR – check out elfs-clang-plugins, cool plugins for clang made at elastifile.

Have you ever made the mistake of returning a bool instead of an enum?

enum Result do_something(void) {
    return true;

In C that’s valid (in C++ you can use ‘class enum’ to avoid it, but if you didn’t you’d have the same problem).

No compiler that I know of warns about this C code. One of our newly-open-sourced clang plugins, flags this (and many other) enum-related mistakes:

clang -Xclang -load -Xclang ./ \
      -Xclang -add-plugin -Xclang enums_conversion \
      -c /tmp/test.c
/tmp/test.c:7:12: error: enum conversion to or from enum Result
    return true;
1 error generated.

The package includes:

  • enums_conversion: Finds implicit casts to/from enums and integral types
  • include_cleaner: Finds unused #includes
  • large_assignment: Finds large copies in assignments and initializations (size is configurable)
  • private: Prevents access to fields of structs that are defined in private.h files

More information at

Because C is… not so safe.


Safer C programming

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