[darwinbuild] some darwintrace ideas

[Kevin Van Vechten]

A progress report...

Completed:

5) translating volfs paths to normal paths, for better logging of  
Carbon File Manager clients.
6) tracking system calls to a pid and process name, so you can filter  
on what a particular process does/did.
9) the #! interpreter of shell scripts should be reported as another  
execve(2) call.

To Be Completed:

1) Full logging of execve(2) arguments
2) shell-escaping the execve(2) arguments so you can copy-paste  
compiler invocations and such.
3) build a shell script to replay a build, to the extent that this is  
possible with shell commands. During a build, there is some  
computation/processing that would not be captured here.
4) synthesize shell commands for some system calls, like mkdir(2)
7) refactoring compiler invocations, etc., to take common sets of  
arguments and store them in a shell variable.
8) Some more semantic interpretation of files and paths based on  
extension, magic, etc.