#include "CException.h" #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wmissing-field-initializers" volatile CEXCEPTION_FRAME_T CExceptionFrames[CEXCEPTION_NUM_ID] = {{ 0 }}; #pragma GCC diagnostic pop //------------------------------------------------------------------------------------------ // Throw //------------------------------------------------------------------------------------------ void Throw(CEXCEPTION_T ExceptionID) { unsigned int MY_ID = CEXCEPTION_GET_ID; CExceptionFrames[MY_ID].Exception = ExceptionID; if (CExceptionFrames[MY_ID].pFrame) { longjmp(*CExceptionFrames[MY_ID].pFrame, 1); } CEXCEPTION_NO_CATCH_HANDLER(ExceptionID); } //------------------------------------------------------------------------------------------ // Explanation of what it's all for: //------------------------------------------------------------------------------------------ /* #define Try { <- give us some local scope. most compilers are happy with this jmp_buf *PrevFrame, NewFrame; <- prev frame points to the last try block's frame. new frame gets created on stack for this Try block unsigned int MY_ID = CEXCEPTION_GET_ID; <- look up this task's id for use in frame array. always 0 if single-tasking PrevFrame = CExceptionFrames[CEXCEPTION_GET_ID].pFrame; <- set pointer to point at old frame (which array is currently pointing at) CExceptionFrames[MY_ID].pFrame = &NewFrame; <- set array to point at my new frame instead, now CExceptionFrames[MY_ID].Exception = CEXCEPTION_NONE; <- initialize my exception id to be NONE if (setjmp(NewFrame) == 0) { <- do setjmp. it returns 1 if longjump called, otherwise 0 if (&PrevFrame) <- this is here to force proper scoping. it requires braces or a single line to be but after Try, otherwise won't compile. This is always true at this point. #define Catch(e) else { } <- this also forces proper scoping. Without this they could stick their own 'else' in and it would get ugly CExceptionFrames[MY_ID].Exception = CEXCEPTION_NONE; <- no errors happened, so just set the exception id to NONE (in case it was corrupted) } else <- an exception occurred { e = CExceptionFrames[MY_ID].Exception; e=e;} <- assign the caught exception id to the variable passed in. CExceptionFrames[MY_ID].pFrame = PrevFrame; <- make the pointer in the array point at the previous frame again, as if NewFrame never existed. } <- finish off that local scope we created to have our own variables if (CExceptionFrames[CEXCEPTION_GET_ID].Exception != CEXCEPTION_NONE) <- start the actual 'catch' processing if we have an exception id saved away */