GitLab

Cleaning should always succeed now

Add changes that we inherit from haskeline

This fixes at least one problem: libHSffi-ghc<version>.so wasn't being
cleaned, because $(dyn_libsuf) wasn't defined while cleaning.

 - remove the main: stuff
 - show the filenames
 - don't clutter the output with imports that aren't involved in
   the cycle

- Needed to get arch-dependent options, eg, on Snow Leopard

So that Cabal, if it wants, can use a more general algorithm to find a
consistent set of packages to use.

- We have -m32 as machine-dependent option for gcc for a 32 bit build
- Like on OpenBSD, SL requires -fno-stack-protector to avoid triggering the
  stack smashing checks inserted by gcc by default on this platform.

This unbreaks make install again.

For type checker warnings, the context information ("In the expression
...") was simply appended to the main message while for proper errors
they live in errMsgExtraInfo.  This allows GHC API clients to drop
that information if not needed.

This makes events smaller and tracing quicker, and speeds up reading
and sorting the trace file.

HEADS UP: this changes the format of event log files.  Corresponding
changes to the ghc-events package are required (and will be pushed
soon).  Normally we would make backwards-compatible changes, but this
changes the format of every event (to remove the capability) so I'm
breaking the rules this time.  This will be the only time we can do
this, since the format becomes public in 6.12.1.

These indicate the size and time span of a sequence of events in the
event log, to make it easier to sort and navigate a large event log.

Flags (from +RTS -?):

  -qg[<n>]  Use parallel GC only for generations >= <n>
            (default: 0, -qg alone turns off parallel GC)
  -qb[<n>]  Use load-balancing in the parallel GC only for generations >= <n>
            (default: 1, -qb alone turns off load-balancing)

these are good defaults for most parallel programs.  Single-threaded
programs that want to make use of parallel GC will probably want +RTS
-qg1 (this is documented).

I've also updated the docs.

In particular, remove the claim that the GC is single-threaded!