[Devel] Debugging Memory Manager added to FreeType sources

[David Turner]

Hello,

  I have just added a new source file, named "src/base/ftdbgmem.c", that
  implements a simple debugging memory manager for FreeType. It is activated
  by defining FT_DEBUG_MEMORY in "ftoption.h"

  It will report simple errors like invalid reallocation requests, double
  deletes, as well as memory leaks (when FT_Done_FreeType is called).

  Note that it's basically the same thing that was previously in the
  "ftmemchk.c" demo program, except that:

   - the blocks are recorded with a hash table, which provides much
     better performance than a linear list :o)

   - all FreeType applications can easily benefit from it, so it can
     be used to debug leaks and bugs that appear in "rare" situations,
     not only in a single demo program..

   - finally, using it requires much more memory than a typical build,
     since it never really "free" the blocks allocated from the heap
     (in order to detect double deletes easily..)

  I'll probably make a few modifications in the future, like using an
  environment variable to determine at run-time wether to use the debugging
  manager or not..


Cheers,

- David

PS: And of course, this thing will go into the MLib as well..