This API is proposed by Nick Kledzik. The semantic is:

  --------------------------------------------------------------------------
   Generate code for merged module into an array of native object files. On 
   success returns a pointer to an array of NativeObjectFile.  The count 
   parameter returns the number of elements in the array.  Each element is 
   a pointer/length for a generated mach-o/ELF buffer.  The buffer is owned
   by the lto_code_gen_t and will be freed when lto_codegen_dispose() is called, 
   or lto_codegen_compile() is called again. On failure, returns NULL 
   (check lto_get_error_message() for details).

   extern const struct  NativeObjectFile*
   lto_codegen_compile_parallel(lto_code_gen_t cg, size_t *count);
  ---------------------------------------------------------------------------

  This API is currently only called on OSX platform. Linux or other Unixes
using GNU gold are not supposed to call this function, because on these systems, 
object files are fed back to linker via disk file instead of memory buffer.

  In this commit, lto_codegen_compile_parallel() simply calls
lto_codegen_compile() to return a single object file. In the near future,
this function is the entry point for compilation with partition. Linker can
blindly call this function even if partition is turned off; in this case,
compiler will return only one object file.

llvm-svn: 189297

It looked misplaced in the main CMakeLists.txt file.

llvm-svn: 189230

lto/CMakeLists.txt: Cut the dep to intrinsics_gen. LTO doesn't depend on it and LTO_static doesn't depend on anything.

llvm-svn: 189086

In order to appease people (in Apple) who accuse me for committing "huge change" (?) without proper review. 

Thank Eric for fixing a compile-warning. 

llvm-svn: 188204

llvm-svn: 188200

  1. Add some helper classes for partitions. They are designed in a
     way such that the top-level LTO driver will not see much difference 
     with or without partitioning.

  2. Introduce work-dir. Now all intermediate files generated during 
     LTO phases will be saved under work-dir. User can specify the workdir
     via -lto-workdir=/path/to/dir. By default the work-dir will be 
     erased before linker exit. To keep the workdir, do -lto-keep, or -lto-keep=1.

    TODO: Erase the workdir, if the linker exit prematurely.  
      We are currently not able to remove directory on signal. The support 
      routines simply ignore directory.

  3. Add one new API lto_codegen_get_files_need_remove().
     Linker and LTO plugin will communicate via this API about which files
    (including directories) need to removed before linker exit.

llvm-svn: 188188

Currently, when an invalid attribute is encountered on processing a .s file,
clang will abort due to llvm_unreachable.  Invalid user input should not cause
an abnormal termination of the compiler.  Change the interface to return a
boolean to indicate the failure as a first step towards improving hanlding of
malformed user input to clang.

Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
llvm-svn: 188047

Revert r185882. This is causing problems with the gold linker and might be better handled by the linker.

llvm-svn: 188029

As of this revision, all functions of LTOCodeGenerator are consistent in
ret-true-on-succ.

Tested on multiple OSes.

llvm-svn: 187864

llvm-svn: 187819

Patch by: Mei Ye

llvm-svn: 187764

llvm-svn: 187761

Patch by Benjamin Scarlet!

llvm-svn: 187641

Function attributes are the future! So just query whether we want to realign the
stack directly from the function instead of through a random target options
structure.

llvm-svn: 187618

Merge consecutive if-regions if they contain identical statements.
Both transformations reduce number of branches.  The transformation
is guarded by a target-hook, and is currently enabled only for +R600,
but the correctness has been tested on X86 target using a variety of
CPU benchmarks.

Patch by: Mei Ye

llvm-svn: 187278

There's no need to specify a flag to omit frame pointer elimination on non-leaf
nodes...(Honestly, I can't parse that option out.) Use the function attribute
stuff instead.

llvm-svn: 187093

The main observation is that we never need both the filesize and the map size.
When mapping a slice of a file, it doesn't make sense to request a null
terminator and that would be the only case where the filesize would be used.

There are other cleanups that should be done in this area:

* A client should not have to pass the size (even an explicit -1) to say if
  it wants a null terminator or not, so we should probably swap the argument
  order.
* The default should be to not require a null terminator. Very few clients
  require this, but many end up asking for it just because it is the default.

llvm-svn: 186984

llvm-svn: 186931

 Use the function attributes to pass along the stack protector buffer size.

 Now that we have robust function attributes, don't use a command line option to
 specify the stack protecto buffer size.

llvm-svn: 186863

There already have two "dead" functions, initialize{IPO|IPA}, defined for 
similar purpose. I decide not to call these two functions for two reasons:
  o. they don't cover all LTO passes (which will soon be separated into IPO 
     and post-IPO passes)
  o. We have not yet figured out the right passes and the ordering for IPO 
     and post-IPO stages, meaning this change is only for the time being.

Since LTO passes are registered, we are now able to print IR before and 
after particular point.

For OSX users:
--------------
  "...-Wl,-mllvm -Wl,-print-after=<pass-name>" will print IR after the
  specified pass.

For Other UNIX with GNU gold linker:
------------------------------------
  "-Wl,-plugin-opt=-print-after=<pass-name>" should work.
  (NOTE: no need for "-Wl,-mllvm")

  Strip "-Wl," if flags are fed directly to linker instead of clang/clang++.

llvm-svn: 186853

This centralizes the handling of O_BINARY and opens the way for hiding more
differences (like how open behaves with directories).

llvm-svn: 186447

  http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RAincremental/builds/4328

Original commit log:
  Use the function attributes to pass along the stack protector buffer
  size.

llvm-svn: 186234

Now that we have robust function attributes, don't use a command line option to
specify the stack protecto buffer size.

llvm-svn: 186217

The problem with running internalize before we're ready to output an object file
is that it may change a 'weak' symbol into an internal one, but that symbol
could be needed by an external object file --- e.g. with arclite.

<rdar://problem/14334895>

llvm-svn: 185882

llvm-svn: 185719

This is dead code since PIC16 was removed in 2010. The result was an odd mix,
where some parts would carefully pass it along and others would assert it was
zero (most of the object streamer for example).

llvm-svn: 185436

Someone may want to do something crazy, like replace these objects if they
change or something.

No functionality change intended.

llvm-svn: 184175

This patch also adds a simpler version of sys::fs::remove and a tool_output_file
constructor for when we already have an open file.

llvm-svn: 184095

llvm-svn: 183947

llvm-svn: 183840

This is preparation for replacing Path.h with PathV2.h.

llvm-svn: 183782

No functionality change.

llvm-svn: 183759

llvm-svn: 183669

Specifying the load address for Darwin i386 dylibs was a performance
optimization for dyld that is not relevant for x86_64 or arm. We can just
remove this now.

llvm-svn: 183230

Not only does this break encapsulation, it's gross.

llvm-svn: 182876

llvm-svn: 182680

Move the processing of the command line options to right before we create the
TargetMachine instead of after.
<rdar://problem/13468287>

llvm-svn: 182611

Update comments, fix * placement, fix method names that are not
used in clang, add a linkInModule that takes a Mode and put it
in Linker.cpp.

llvm-svn: 181099

The linker is now responsible only for actually linking the modules, it
is up to the clients to create and destroy them.

llvm-svn: 181098

llvm-svn: 181096