1
0
mirror of https://github.com/catseye/SixtyPical.git synced 2024-11-22 17:32:01 +00:00
A 6502-oriented low-level programming language supporting advanced static analysis
Go to file
2017-12-11 12:02:48 +00:00
bin Ability to --debug analysis. Make 16-bit addition test pass. 2017-12-07 11:49:15 +00:00
doc Amend spec with brief description of new behaviour of add. 2017-12-07 15:34:06 +00:00
eg copy from word storage to word table and back, indexed by x or y. 2017-12-11 12:02:48 +00:00
src/sixtypical copy from word storage to word table and back, indexed by x or y. 2017-12-11 12:02:48 +00:00
tests copy from word storage to word table and back, indexed by x or y. 2017-12-11 12:02:48 +00:00
.gitignore
.hgignore
.hgtags Added tag 0.6 for changeset f89772f47de9 2015-10-23 16:37:22 +01:00
HISTORY.markdown copy from word storage to word table and back, indexed by x or y. 2017-12-11 12:02:48 +00:00
LICENSE
loadngo.sh Use right endianness when copying literal word into storage. 2017-12-07 16:49:43 +00:00
README.markdown Break the ground where we need to implement word table read/write. 2017-12-08 15:53:18 +00:00
test.sh Add syntax for extern routines, add syntax tests. 2015-10-17 13:50:21 +01:00

SixtyPical

SixtyPical is a very low-level programming language, similar to 6502 assembly, with static analysis through abstract interpretation.

In practice, this means it catches things like

  • you forgot to clear carry before adding something to the accumulator
  • a subroutine that you call trashes a register you thought was preserved
  • you tried to write the address of something that was not a routine, to a jump vector

and suchlike. It also provides some convenient operations and abstractions based on common machine-language programming idioms, such as

  • copying values from one register to another (via a third register when there are no underlying instructions that directly support it)
  • explicit tail calls
  • indirect subroutine calls

The reference implementation can execute, analyze, and compile SixtyPical programs to 6502 machine code.

SixtyPical is a work in progress. The current released version of SixtyPical is 0.9-PRE (not released yet.)

Documentation

TODO

Operations on 16 bit values

Compare word (constant or memory location) with memory location or pointer. (Maybe?)

And then write a little demo "game" where you can move a block around the screen with the joystick.

vector table type

low and high address operators

To turn word type into byte.

save registers on stack

This preserves them, so that, semantically, they can be used later even though they are trashed inside the block.

And at some point...

  • copy x, [ptr] + y
  • Maybe even copy [ptra] + y, [ptrb] + y, which can be compiled to indirect LDA then indirect STA!
  • Check that the buffer being read or written to through pointer, appears in approporiate inputs or outputs set.
  • initialized byte table memory locations
  • always analyze before executing or compiling, unless told not to
  • trash instruction.
  • interrupt routines.
  • 6502-mnemonic aliases (sec, clc)
  • other handy aliases (eq for z, etc.)
  • have copy instruction able to copy a constant to a user-def mem loc, etc.
  • add absolute addressing in shl/shr, absolute-indexed for add, sub, etc.
  • check and disallow recursion.
  • automatic tail-call optimization (could be tricky, w/constraints?)
  • re-order routines and optimize tail-calls to fallthroughs