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This fixes #5106 (objc compilation was failing on i386 Darwin).

Previously the code generator generated small code fragments labelled
with __stginit_M for each module M, and these performed whatever
initialisation was necessary for that module and recursively invoked
the initialisation functions for imported modules.  This appraoch had
drawbacks:

 - FFI users had to call hs_add_root() to ensure the correct
   initialisation routines were called.  This is a non-standard,
   and ugly, API.

 - unless we were using -split-objs, the __stginit dependencies would
   entail linking the whole transitive closure of modules imported,
   whether they were actually used or not.  In an extreme case (#4387,
   #4417), a module from GHC might be imported for use in Template
   Haskell or an annotation, and that would force the whole of GHC to
   be needlessly linked into the final executable.

So now instead we do our initialisation with C functions marked with
__attribute__((constructor)), which are automatically invoked at
program startup time (or DSO load-time).  The C initialisers are
emitted into the stub.c file.  This means that every time we compile
with -prof or -hpc, we now get a stub file, but thanks to #3687 that
is now invisible to the user.

There are some refactorings in the RTS (particularly for HPC) to
handle the fact that initialisers now get run earlier than they did
before.

The __stginit symbols are still generated, and the hs_add_root()
function still exists (but does nothing), for backwards compatibility.

This code has accumulated a great deal of cruft over the years, this
pass cleans up a lot of the surrounding cruft but leaves the actual
argument processing alone - so there's still more that could be done.

Bug fixed:

  - ghc_rts_opts should not be subject to the --rtsopts setting.  If
    the programmer explicitly declares options with ghc_rts_opts, they
    shouldn't also have to accept command-line RTS options to make them
    work.

real bug, spotted by Marcin Orczyk (thanks!).  I'm not sure if it lead
to any actual crashes.

Warning: This change seems to tickle a bug in ghc-stage1 compiler
built with GHC 6.12.1 during validates.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

The new code generator was doing some interesting spilling across
unsafe foreign calls:

     _c1ao::I32 = Hp - 4;
     I32[Sp - 20] = _c1ao::I32;
     foreign "ccall"
       newCAF((BaseReg, PtrHint), (R1, PtrHint))[_unsafe_call_];
     _c1ao::I32 = I32[Sp - 20];

This is fairly unnecessary, and resulted from over-conservative
liveness analysis from CmmLive.  We can see that the old code
generator only saved volatile registers across unsafe foreign calls:
spilling variables was done by saveVolatileVarsAndRegs, which was
only performed for ordinary calls.

This commit removes the excess kill from the liveness analysis, as well
as the *redundant* excess kill from spilling-and-reloading, and adds a
note to CmmNode to this effect.  The only registers we need to kill
are the ones that the foreign call assigns to, just like any other
machine instruction.
Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

This is a port of some of the changes from my private local-GC branch
(which is still in darcs, I haven't converted it to git yet).  There
are a couple of small functional differences in the GC stats: first,
per-thread GC timings should now be more accurate, and secondly we now
report average and maximum pause times. e.g. from minimax +RTS -N8 -s:

                                    Tot time (elapsed)  Avg pause  Max pause
  Gen  0      2755 colls,  2754 par   13.16s    0.93s     0.0003s    0.0150s
  Gen  1       769 colls,   769 par    3.71s    0.26s     0.0003s    0.0059s

otherwise we repeatedly try to rebuild ghc-pkg if ghc-cabal is newer.

Based on the darcs patch from Greg Wright in #4828.

Part of the patch from #5062, from Greg Wright.

We are now more lenient in parsing the packages file, and
we don't use any GNUisms. Based on a patch from Matthias Kilian.

A common sequence of commands (at least for me) is this:

$ ghc hello
1 of 1] Compiling Main             ( hello.hs, hello.o )
Linking hello ...
$ ./hello +RTS -s
hello: Most RTS options are disabled. Link with -rtsopts to enable them.
$ ghc hello -rtsopts
$

grr, nothing happened.  I could use -fforce-recomp, but if this was a
large program I probably don't want to recompile it all again, so:

$ rm hello
removed `hello'
$ ghc hello -rtsopts
Linking hello ...
$ ./hello +RTS -s
./hello +RTS -s
Hello World!
          51,264 bytes allocated in the heap
           2,904 bytes copied during GC
          43,808 bytes maximum residency (1 sample(s))
          17,632 bytes maximum slop
etc.

With this patch, GHC notices when the options have changed and forces
a relink, so you don't need to rm the binary or use -fforce-recomp.
This is done by adding the pertinent stuff to the binary in a special
section called ".debug-ghc-link-info":

$ readelf -p .debug-ghc-link-info ./hello
String dump of section 'ghc-linker-opts':
  [     0]  (["-lHSbase-4.3.1.0","-lHSinteger-gmp-0.2.0.2","-lgmp","-lHSghc-prim-0.2.0.0","-lHSrts","-lm","-lrt","-ldl","-u","ghczmprim_GHCziTypes_Izh_static_info","-u","ghczmprim_GHCziTypes_Czh_static_info","-u","ghczmprim_GHCziTypes_Fzh_static_info","-u","ghczmprim_GHCziTypes_Dzh_static_info","-u","base_GHCziPtr_Ptr_static_info","-u","base_GHCziWord_Wzh_static_info","-u","base_GHCziInt_I8zh_static_info","-u","base_GHCziInt_I16zh_static_info","-u","base_GHCziInt_I32zh_static_info","-u","base_GHCziInt_I64zh_static_info","-u","base_GHCziWord_W8zh_static_info","-u","base_GHCziWord_W16zh_static_info","-u","base_GHCziWord_W32zh_static_info","-u","base_GHCziWord_W64zh_static_info","-u","base_GHCziStable_StablePtr_static_info","-u","ghczmprim_GHCziTypes_Izh_con_info","-u","ghczmprim_GHCziTypes_Czh_con_info","-u","ghczmprim_GHCziTypes_Fzh_con_info","-u","ghczmprim_GHCziTypes_Dzh_con_info","-u","base_GHCziPtr_Ptr_con_info","-u","base_GHCziPtr_FunPtr_con_info","-u","base_GHCziStable_StablePtr_con_info","-u","ghczmprim_GHCziTypes_False_closure","-u","ghczmprim_GHCziTypes_True_closure","-u","base_GHCziPack_unpackCString_closure","-u","base_GHCziIOziException_stackOverflow_closure","-u","base_GHCziIOziException_heapOverflow_closure","-u","base_ControlziExceptionziBase_nonTermination_closure","-u","base_GHCziIOziException_blockedIndefinitelyOnMVar_closure","-u","base_GHCziIOziException_blockedIndefinitelyOnSTM_closure","-u","base_ControlziExceptionziBase_nestedAtomically_closure","-u","base_GHCziWeak_runFinalizzerBatch_closure","-u","base_GHCziTopHandler_runIO_closure","-u","base_GHCziTopHandler_runNonIO_closure","-u","base_GHCziConcziIO_ensureIOManagerIsRunning_closure","-u","base_GHCziConcziSync_runSparks_closure","-u","base_GHCziConcziSignal_runHandlers_closure","-lHSffi"],Nothing,RtsOptsAll,False,[],[])

And GHC itself uses the readelf command to extract it when deciding
whether to relink.  The reason for the name ".debug-ghc-link-info" is
that sections beginning with ".debug" are removed automatically by
strip.

This currently only works on Linux; Windows and OS X still have the
old behaviour.

By default, git will clone in autocrlf mode, which on Windows means
we get '\r's added to the ghc-packages files.

not the _stub.c file, because the latter is now created as a temporary
file.

You can set up remotes and give them as an argument
"./sync-all pull someremote" instead. The old way meant
that the patches would be pulled, but remotes/origin/master
wouldn't be updated.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

* origin:
  Revert "Suppress dumpTcRn when -dno-debug-output is enabled."

* 'trac_5025' of https://github.com/thoughtpolice/ghc:
  Teach GHC to compile objective-c files; trac #5025

Conflicts:
	compiler/main/DriverPipeline.hs

This reverts commit 12929a21.

to the way stub files were handled.

in a LANGUAGE pragma, but it is parsed by parseDynamicFlags, and it
can be set per-session in the GHC API.  We don't have a name for this
type of flag, but from the user's point of view "static" is probably
less confusing.