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[[!meta title="Documentation/Errors"]]
[[!meta author="James Bursa"]]
[[!meta date="2010-03-01T02:55:53Z"]]
[[!toc]] This section describes
error handling in the code.
The most common serious error is memory exhaustion. If malloc(),
strdup(), etc. fails, clean up and free any partially complete
structures leaving data in a consistent state, and return a value which
indicates failure, eg. 0 for functions which return a pointer (document
the value in the function documentation). The caller should then
propagate the failure up in the same way. At some point, the error
should stop being passed up and be reported to the user using
warn_user("NoMemory", 0);
The other common error is one returned by a RISC OS SWI. Always use "X"
SWIs, something like this:
os_error *error;
error = xwimp_get_pointer_info(&pointer);
if (error) {
LOG(("xwimp_get_pointer_info: 0x%x: %s\n",
error->errnum, error->errmess));
warn_user("WimpError", error->errmess);
return false;
}
If an error occurs during initialisation, in most cases exit immediately
using die(), since this indicates that there is already insufficient
memory, or a resource file is corrupted, etc.
[[!inline raw=yes pages="Documentation"]]
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