[GHC] #946: Complete and integrate a tags and module-graph analyser using the GHC API

[GHC]

#946: Complete and integrate a tags and module-graph analyser using the GHC API
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    Reporter:  simonpj           |       Owner:         
        Type:  task              |      Status:  new    
    Priority:  normal            |   Milestone:         
   Component:  Compiler          |     Version:  6.6    
    Severity:  normal            |    Keywords:         
  Difficulty:  Moderate (1 day)  |    Testcase:         
Architecture:  Unknown           |          Os:  Unknown
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Norman and Kathleen started a tags-file generator based on the GHC Api.
 Their patch is attached (description below).

 This task is to keep track of their patch, and to encourage any
 enthusiasts to finish the job.  Things to think about

  * Norman and Kathleen had it structured as a standalone application,
 using the GHC Api. That makes sense, but it's awkward to put it into GHC's
 build tree, because there is no build-system support for "build this tool
 after GHC stage2 is built".  Furthermore, we would not want to distribute
 it as a standalone binary in the GHC distribution, because (lacking shared
 libraries) it'd be another 10M binary!

  Conclusion: either make it a completely independent repository, built
 with Cabal etc, or integrate it into GHC, so you can say `ghc --tags`

  * There's an existing small tags-generation thing, invokable from GHCi
 only (:tags). Don't want to duplicate.

  * Much of the same technology would be useful to generate other useful
 info. Specifically (a) module dependency graphs, (b) function dependency
 graphs within a module.

  * Norman and Kathleen encontered performance problems, becuase they call
 `checkModule` on every module. That's perfectly reasonable, but it
 stupidly makes GHC do a full dependency analysis each time; result
 quadratic behaviour.  This should be fixed by thinking about the GHC Api
 design.

 Here are the patch descriptions for the attached patch
 {{{
 Fri Sep 15 19:50:33 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * initial, very incomplete tags generator
   The ultimate goal is to replace hasktags with
   a tags generator based on GHC-as-a-library.
   This file is a very incomplete first cut.

 Sat Sep 16 19:27:55 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * cover more cases; take GHC options on command line
   Bit of a dog's breakfast here:
     * generate tags for more cases in the syntax
     * accept -package ghc and other args on command line
     * scrub away old code for snaffling thru text

 Sat Sep 16 20:23:53 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * tell GHC not to generate code (thanks Simon M)

 Sat Sep 16 20:24:30 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * load all files at once and compute tags for all

 Sat Sep 16 20:34:10 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * do notation for the Maybe monad

 Sat Sep 16 21:15:29 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * desperate attempts to handle the GHC build
   What's happening here is a series of attempts to successfully swallow
   what the GHC build process chooses to throw at the tool.  I'm clearly
   out of my depth and so will revert to trying one module at a time.

 Sat Sep 16 21:54:51 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * if the whole group fails, try one file at a time

 Sat Sep 16 21:55:39 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * get names of data constructors

 Sun Sep 17 01:08:00 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * change representation of FoundThing
   refactored FoundThing to use GHC's native representation of
   source-code locations and to carry the module name so that the TAGS
   file can contain a qualified name as well as the unqualified name

 Sun Sep 17 01:30:46 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * refactoring for more readable source code

 Wed Sep 20 00:26:07 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * working 'ghctags' Makefile target (requires stage=2)

 Wed Sep 20 00:27:57 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * first cut at missing case for ids defined in pattern

 Wed Sep 20 00:28:39 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * proper HC entry for bootstrapping in Makefile

 Wed Sep 20 00:29:13 EDT 2006  Norman Ramsey <nr at eecs.harvard.edu>
   * correct minor spelling error s/patterng/pattern/

 Fri Oct 13 16:27:56 EDT 2006  nr at eecs.harvard.edu
   * new README file for utils/ghctags

 Fri Oct 13 16:28:25 EDT 2006  nr at eecs.harvard.edu
   * accomodate changes in the GHC API

 Fri Oct 13 16:29:22 EDT 2006  nr at eecs.harvard.edu
   * request for documentation of a new argument
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/946>
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