Dragonfail

Dragonfail is a simple library providing basic error handling functionnalities. It was designed to be as lightweight as possible, and can be completely disabled with only one #define (more on that later).

Dragonfail was designed to be fast and uses inline functions exclusively. These calls modify a global context which is not directly accessible by the programmer.

All the error codes must be written in an enum in your dragonfail_error.h file. Because of this rather unusual architecture, the file must be found by the compiler when it is processing dragonfail.c (in addition to your own source code of course).

Testing

Run make to compile an example, and make run to execute it.

Defines

This header can also contain some #define to modify dragonfail's behaviour:

• DRAGONFAIL_SKIP completely disables the whole library, making it completely disappear from the binary (unless your compiler is a massive douche).
• DRAGONFAIL_BASIC_LOG enables the dgn_basic_log() function calls
• DRAGONFAIL_THROW_BASIC_LOG makes dgn_throw() call dgn_basic_log() automatically
• DRAGONFAIL_THROW_DEBUG_LOG also prints the file and line in which dgn_throw() is called (you don't even need to compile with symbols because this is achieved the smart way using simple C99 macros)
• DRAGONFAIL_ABORT makes dgn_throw() call abort()

Again, these #define must be placed in your dragonfail_error.h file.

Using

TL;DR

see the example folder :)

Documentation

char** dgn_init();

This intializes the context to DGN_OK (no error) and returns the array of strings you can fill with log messages corresponding to the errors you added in the enum.

void dgn_reset();

This resets the context to DGN_OK.

void dgn_basic_log();

This prints the message corresponding to the current error to stderr.

void dgn_throw(enum dgn_error new_code);

This sets the error to the given code.

char dgn_catch();

This returns true if the context currently holds an error

Why is the architecture so strange?

The dragonfail context is global (extern) but really implemented in dragonfail.c. Its type depends on the size of the enum so it is declared in dragonfail_private.h: this way we can include the user's dragonfail_error.h and get DGN_SIZE.

The inline functions need to access this context and we want it private, so we can't implement them directly in the header as a lot of people seem to appreciate. Instead, we will declare them here, and put the implementations in dragonfail.c: this way we can access the global context without including its declaration, because it is implemented here as well.

When you include dragonfail.h, you get access to the inline functions declarations and thanks to this design any compiler will do the rest of the job automatically. Yes, this whole thing is useless and over-engineered. And yes, I had fun doing it...

Greetings

Jinjer for the cool music \m/ Haiku developers for indirectly giving me the idea