Version 92 (modified by SamB, 11 years ago) (diff)

old commentary no longer available in chak's webspace; refer to copy in main darcs repo instead

The GHC Commentary

This tree of wiki pages is a "commentary" on the GHC source code. It contains all the explanatory material that doesn't belong in comments in the source code itself, because the material is wide-ranging, usually covers multiple source files, and is more architectural in nature. The commentary can also be considered a design document for GHC.

For the dedicated, there are videos of Simon and Simon giving an overview of GHC, at the 2007 GHC Hackathon.

GHC Hackathon.

Please feel free to add material to this commentary: don't worry too much about accuracy, in due course someone will edit your contribution. Try to link to source files as much as possible by using this macro: [[GhcFile(compiler/Makefile)]] (the usual Trac source: macro doesn't work here because the GHC darcs repository isn't integrated into this Trac). Also try to add appropriate links to other parts of the commentary.


Contributed Documentation

Please feel free to add new pages here. In due course information will migrate from here to the main commentary above.

  • The Runtime System
    • GarbageCollectorNotes Notes about GHC's existing single threaded garbage collector and development of a parallel GC.
    • GMPMemoryManagement Describes how the garbage collector cooperates with GMP for Integer.
    • SemiTagging: Describes how the semi-tagging optimisation will be implemented.
    • PAPI: Measurement of program performance usign CPU events (cache misses, branch mispredictions).
  • Other Cross-cutting concerns: topics which span both the compiler and the runtime system
  • Getting to grips with the code base
    • BeginnersNotes: Some notes about getting started hacking GHC and the structure of the compiler (especially types and typecheck)

Old but useful

Finally, here are some generally-useful, but now somewhat-out-of-date resources:

  • The old GHC Commentary: Information on the internals of GHC, in various states of up-to-dateness. We are keen to move this stuff out of its current location and onto this Wiki. If anyone is willing to help do that, even for just a part in which you are interested, we would be delighted.
  • GhcPapers: papers and pointers to other documents that relate to the inner workings of GHC.

Convert type diagram to SVG? Upload graphviz source?