[Libjit-developers] Patch for dpas-parser.y to implement array expressions

[Avinash Atreya]

Hi All,

Finally, I have the patch for implementing array expresions in dpas.
Spent a few hours in the last three days trying to figure out some
errors. Finally decided to submit it as it looked on Saturday :).

I have also attached the test file that i have used: array.pas.

A few things about the patch:

The documentation states that the fact that pointers can be used to
access arrays in an unbounded fashion is a deviation from standard
pascal and needs to be used carefully. Though I have got subscript
expressions to work with pointers there are a few gotchas. I am not
sure how exactly rhys wanted arrays to be assigned to pointers so that
subscripts can be used with them.

pointer = @simple_array[i] seems to work only if i ==
low(simple_array). For all other offsets, the address gets screwed up
during assignment. That is, it is not offset by the desired amount.
pointer = simple_array ( c style ) leads to weird errors.
jit_function_compile returns 0 because _jit_cache_end_method returns
JIT_CACHE_END_TOO_BIG. I couldn't do anything more with that.

When array indices are out of bounds, an exception is thrown. This
seg-faults in jit mode as well as interpreted mode. Gopal was telling
me that exceptions have not been implemented, that could be a possible
reason. Also, i am throwing 0 along with the exception, not sure what
would be a good value to throw. The index which was out of bounds?

Everything else works fine :P

Thanks
Regards
Avinash

arrays.patch
Description: Binary data

array.pas
Description: Binary data