mirror of
https://github.com/catseye/SixtyPical.git
synced 2024-11-24 15:32:27 +00:00
140 lines
5.6 KiB
Markdown
140 lines
5.6 KiB
Markdown
SixtyPical
|
|
==========
|
|
|
|
_Version 0.21. Work-in-progress, everything is subject to change._
|
|
|
|
**SixtyPical** is a [low-level](#low-level) programming language
|
|
supporting a sophisticated [static analysis](#static-analysis).
|
|
Its reference compiler can generate [efficient code](#efficient-code) for
|
|
several 6502-based [target platforms](#target-platforms) while catching many
|
|
common mistakes at compile-time, reducing the time spent in debugging.
|
|
|
|
Quick Start
|
|
-----------
|
|
|
|
Make sure you have Python (2.7 or 3.5+) installed. Then
|
|
clone this repository and put its `bin` directory on your
|
|
executable search path. Then you can run:
|
|
|
|
sixtypical
|
|
|
|
If you have the [VICE][] emulator suite installed, you can run
|
|
|
|
sixtypical --run-on=x64 eg/c64/hearts.60p
|
|
|
|
and it will compile the [hearts.60p source code](eg/c64/hearts.60p) and
|
|
automatically start it in the `x64` emulator, and you should see:
|
|
|
|
|
|
|
|
You can try `sixtypical --run-on` on other sources in the `eg` directory
|
|
tree, which contains more extensive examples, including an entire
|
|
game(-like program); see [eg/README.md](eg/README.md) for a listing.
|
|
|
|
Features
|
|
--------
|
|
|
|
SixtyPical aims to fill this niche:
|
|
|
|
* You'd use assembly, but you don't want to spend hours
|
|
debugging (say) a memory overrun that happened because of a
|
|
ridiculous silly error.
|
|
* You'd use C or some other "high-level" language, but you don't
|
|
want the extra overhead added by the compiler to manage the
|
|
stack and registers.
|
|
|
|
SixtyPical gives the programmer a coding regimen on par with assembly
|
|
language in terms of size and hands-on-ness, but also able to catch
|
|
many ridiculous silly errors at compile time.
|
|
|
|
### Low level
|
|
|
|
Many of SixtyPical's primitive instructions resemble those of the
|
|
[MOS Technology 6502][] — it is in fact intended to be compiled to 6502
|
|
machine code. However, it also provides some "higher-level" operations
|
|
based on common 8-bit machine-language programming idioms, including
|
|
|
|
* copying values from one register to another (via a third register when
|
|
there are no underlying instructions that directly support it)
|
|
* copying, adding, and comparing 16-bit values (done in two steps)
|
|
* explicit tail calls
|
|
* indirect subroutine calls
|
|
|
|
While a programmer will find these constructs convenient, their
|
|
inclusion in the language is primarily to make programs easier to analyze.
|
|
|
|
### Static analysis
|
|
|
|
The SixtyPical language defines an [effect system][], and the reference
|
|
compiler [abstractly interprets][] the input program to check that
|
|
it conforms to it. It can detect common mistakes such as
|
|
|
|
* you forgot to clear carry before adding something to the accumulator
|
|
* a subroutine that you called trashes a register you thought it preserved
|
|
* you tried to read or write a byte beyond the end of a byte array
|
|
* you tried to write the address of something that was not a routine, to
|
|
a jump vector
|
|
|
|
### Efficient code
|
|
|
|
Unlike most conventional languages, in SixtyPical the programmer must manage
|
|
memory very explicitly, selecting the registers and memory locations to store
|
|
each piece of data in. So, unlike a C compiler such as [cc65][], a SixtyPical
|
|
compiler doesn't need to generate code to handle [calling conventions][] or
|
|
[register allocation][]. This results in smaller (and thus faster) programs.
|
|
|
|
The flagship demo, a minigame for the Commodore 64, compiles to
|
|
a **930**-byte `.PRG` file.
|
|
|
|
### Target platforms
|
|
|
|
The reference implementation can analyze and compile SixtyPical programs to
|
|
6502 machine code formats which can run on several 6502-based 8-bit architectures:
|
|
|
|
* [Commodore 64][]
|
|
* [Commodore VIC-20][]
|
|
* [Atari 2600][]
|
|
* [Apple II series][]
|
|
|
|
For example programs for each of these, see [eg/README.md](eg/README.md).
|
|
|
|
Specification
|
|
-------------
|
|
|
|
SixtyPical is defined by a specification document, a set of test cases,
|
|
and a reference implementation written in Python.
|
|
|
|
There are over 400 test cases, written in [Falderal][] format for readability.
|
|
In order to run the tests for compilation, [dcc6502][] needs to be installed.
|
|
|
|
* [SixtyPical specification](doc/SixtyPical.md)
|
|
* [Literate test suite for SixtyPical syntax](tests/SixtyPical%20Syntax.md)
|
|
* [Literate test suite for SixtyPical analysis (operations)](tests/SixtyPical%20Analysis.md)
|
|
* [Literate test suite for SixtyPical analysis (storage)](tests/SixtyPical%20Storage.md)
|
|
* [Literate test suite for SixtyPical analysis (control flow)](tests/SixtyPical%20Control%20Flow.md)
|
|
* [Literate test suite for SixtyPical compilation](tests/SixtyPical%20Compilation.md)
|
|
* [Literate test suite for SixtyPical fallthru optimization](tests/SixtyPical%20Fallthru.md)
|
|
|
|
Documentation
|
|
-------------
|
|
|
|
* [Design Goals](doc/Design%20Goals.md)
|
|
* [SixtyPical revision history](HISTORY.md)
|
|
* [6502 Opcodes used/not used in SixtyPical](doc/6502%20Opcodes.md)
|
|
* [Output formats supported by `sixtypical`](doc/Output%20Formats.md)
|
|
* [TODO](TODO.md)
|
|
|
|
[MOS Technology 6502]: https://en.wikipedia.org/wiki/MOS_Technology_6502
|
|
[effect system]: https://en.wikipedia.org/wiki/Effect_system
|
|
[abstractly interprets]: https://en.wikipedia.org/wiki/Abstract_interpretation
|
|
[calling conventions]: https://en.wikipedia.org/wiki/Calling_convention
|
|
[register allocation]: https://en.wikipedia.org/wiki/Register_allocation
|
|
[VICE]: http://vice-emu.sourceforge.net/
|
|
[cc65]: https://cc65.github.io/
|
|
[Commodore 64]: https://en.wikipedia.org/wiki/Commodore_64
|
|
[Commodore VIC-20]: https://en.wikipedia.org/wiki/Commodore_VIC-20
|
|
[Atari 2600]: https://en.wikipedia.org/wiki/Atari_2600
|
|
[Apple II series]: https://en.wikipedia.org/wiki/Apple_II_series
|
|
[Falderal]: https://catseye.tc/node/Falderal
|
|
[dcc6502]: https://github.com/tcarmelveilleux/dcc6502
|