[CIG-LONG] Help for reading source code

[Walter Landry]

Feng Lin <rimbong at gmail.com> wrote:
> Hey everyone,
> 
> Sometimes, I hope I could understand the source code of Gale(2.0) so
> that I could check and solve some questions by myself.
> But when I went into the directory of the Gale, there are like 12
> directories inside there and a lot of subdirectories in each
> directory.
> Anyone can give me any advice for how to get start ?

The code, is, unfortunately, not easy to read.  To briefly describe
what the directories contain

json_parser/

  Code to handle parsing the json input format.  It mostly sets up
  defaults and handles the actual parsing off to json_spirit.

json_spirit/

  A copy of the JSON Spirit library that does the actual parsing of
  the json files.  It uses the boost library.
  
boost/
  A copy of the boost library from boost.org.  This is mainly used by
  the json parser.

muparserx/

  A copy of the muParserX library used for parsing equations in input files.

doc/

  The images and source files for building the manual.

input/

  Benchmark and cookbook input files

config/

  Python code to handle the initial configuration of Gale when
  building from source.

script/

  A Python script to assist the configuration.  I do think that I use it.

StGermain/

  Foundational code to handle parallelism, boundary
  conditions, initial conditions, reading XML, plugins, and the object
  system.  The object system, in a sense, reinvents C++ classes using
  all sorts of macro tricks.

StgDomain/

  Handles Shapes and meshing.  It also has some basic code for particles.

StgFEM/

  Implements the Finite Element method.  This is where the basic
  physics gets implemented (Stokes, advection/diffusion).

PICellerator/

  Handles the mapping between particles and material properties.  Also
  handles population control for the particle.

Underworld/

  Implements the various rheologies (Drucker-Prager, Non-Newtonian, etc.)

gLucifer/

  Code for creating visualizations during a run.  Not used.


If you want to see where the code starts, that is

  StGermain/src/main.cxx

It reads in the input file and creates components based on that.  It
then dynamically calls functions based on these components.  I have
not found it profitable to use a debugger to single-step through the
code starting from main().

If you want to debug a component, I would recommend setting a
breakpoint in that component with a debugger.  Then run the code and
you can get a stack trace showing how that component is called.

Cheers,
Walter Landry