Subvert the dominant paradigm

Up until now I have managed to make do without a garbage collector. My development machine has 4 gigabytes of RAM, which allowed me to compile all the test cases, but was not large enough for bootstrapping. I thought it would be fairly easy to plug in the Boehm garbage collector since my system is so simple, but I still encountered a few problems:

• The data objects in the ELF objects emitted by my compiler were not word-aligned. I had set the addralign field for the .data segment to 4, but the objects weren’t aligned. This might have caused the Boehm garbage collector to miss pointers in these objects.
• Previously I was using malloc, which on my system returns objects aligned to an 8-byte boundary. Church relies on this because it uses the lower 3 bits of a word as a tag. To get the Boehm gc to align allocated memory meant compiling it with the -DALIGN_DOUBLE flag. I couldn’t figure out how to do this with the latest 7.1 release, so I used the 6.8 release instead
• For some reason, if small objects are allocated they aren’t aligned either, so I have to request a minimum of 8 bytes per allocation

I have completed the port of the State compiler and the ELF writer. Still remaining is most of the Church compiler and some x86 machine instructions.

The ported system is in the “genesis” subdirectory (click on “files” to see the directory tree)

http://subvert-the-dominant-paradigm.net/repos/hgwebdir.cgi/bootstrap/

Update (Jan 15th): I have ported the whole system such that it can compile the Church runtime code and generate executables. The work remaining is to debug the generated code until it is able to compile and run the whole Church/State system.

Update (Jan 20th): All the Church test cases are working with the ported codebase.