[Patch] Augment bitten-slave exit code for --no-loop.

[mpotter@…]

The bitten-slave currently returns various exit codes for various failure cases. If would be nice if when used with the --no-loop option, bitten-slave could return info on if it built anything or not.

bitten-slave --no-loop --single will build 0 or 1 targets. bitten-slave --no-loop will build 0 or many targets. Since 0 is normally considered a success case for commands, and any other value an error:

• If "bitten-slave --no-loop ..." builds no targets
  • return 1.
• If "bitten-slave --no-loop ..." builds 1 or more targets,
  • return 0.
• If "bitten-slave ..." fails,
  • return the appropriate error code as it currently does.

Use-case: I was thinking I could wrap bitten-slave in a script and use the --no-loop and --single options with various slave configurations to implement a simple priority system.

Pseudo-code:

do {
   do {

      # Build all high-priority targets
      bitten-slave --no-loop -f HighPriority.ini ...

      # Try to build one medium or high priority target
      bitten-slave --no-loop --single -f MedOrHighPriority.ini ...

   # loop back in case a new high priority has appeared
   } while ( errorlevel == 1 );

   # Build one target.  Wait if there are not any available.
   bitten-slave --single -f AnyPriority.ini ...

# If not an error, loop back
} while ( errorlevel == 0 );

[Mark Potter <mpotter@…>]

Patch to implement no-loop exit code difference if built something or not.

[Mark Potter <mpotter@…>]

Added a patch that implements this feature. However, instead of using an exit-code of 1 to indicate that the slave built nothing, I used EX_NOTFOUND. However, EX_NOTFOUND does not appear to be defined on many platforms. Following the pattern for the other EX_ values, and searching for what EX_NOTFOUND is typically defined as when it is defined, I went when 79.

[Mark Potter <mpotter@…>]

Sample Windows Batch file that uses this change to implement a simple build priority system.