CException.c

#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
 */