The only functions that do not alter waffle's error state are listed here and are explicitly documented as such. All functions listed here can be called before waffle has been successfully initialized with waffle_init(3)

struct waffle_error_info

This struct contains the user-visible portion of waffle's thread-local error state.

code may be any token from enum waffle_error.

message often contains a descriptive message about the error. It is never null, though it may be the empty string.

message_length is the length of message according to strlen(3).

waffle_error_to_string()

Convert a waffle_error token to a string. For example, convert WAFFLE_ERROR_UNKNOWN to "WAFFLE_ERROR_UNKNOWN". Return null if the token is not a valid error token.

This function always sets the error code to WAFFLE_ERROR_NONE.

waffle_error_get_info()

Get information about the current thread's error state.

This function never returns null. The returned pointer becomes invalid when the thread-local error state changes.

This function does not alter waffle's error state.

waffle_error_get_code()

Get the current thread's error code. Calling this function is equivalent to obtaining the error code with waffle_error_get_info()->code.

This function does not alter waffle's error state.

enum waffle_error

For reference, below is the complete list of waffle's error codes.

WAFFLE_NO_ERROR = 0x00

The function succeeded.

WAFFLE_ERROR_FATAL = 0x01

Waffle encountered a fatal error. All future waffle calls result in undefined behavior.

WAFFLE_ERROR_UNKNOWN = 0x02

Waffle encountered an error for which it lacks an error code. This is usually produced when an underlying native call, such as XOpenDisplay(3), fails for an unknown reason.

WAFFLE_ERROR_INTERNAL = 0x03

You found a bug in waffle. Please report it. The error message, obtained by waffle_error_get_info(), should contain a description of the bug.

WAFFLE_ERROR_BAD_ALLOC = 0x04

Waffle failed to allocate memory.

WAFFLE_ERROR_NOT_INITIALIZED = 0x05

The failed function requires waffle to be initialized with waffle_init(3).

WAFFLE_ERROR_ALREADY_INITIALIZED = 0x06

If waffle has already been initialized by a successful call to waffle_init(3), then subsequent calls to waffle_init() produce this error.

WAFFLE_ERROR_BAD_ATTRIBUTE = 0x08

An unrecognized attribute name or attribute value was passed in an attribute list.

WAFFLE_ERROR_BAD_PARAMETER = 0x10

The failed function was passed an invalid argument.

WAFFLE_ERROR_BAD_DISPLAY_MATCH = 0x11

The waffle objects passed to the failed function belong to different displays.

WAFFLE_ERROR_UNSUPPORTED_ON_PLATFORM = 0x12

The requested action is unsupported on the current system or platform, but is otherwise valid.

For example, attempting to choose a waffle_config whose API is OpenGL ES1 on a system that doesn't OpenGL ES1 will produce this error.

WAFFLE_ERROR_BUILT_WITHOUT_SUPPORT = 0x13

Waffle was built without support for the requested action.

For example, if waffle was built without support for GBM, then calling waffle_init() with attribute WAFFLE_PLATFORM=WAFFLE_PLATFORM_GBM will produce this error.