Subzero: Build both Debug and Release version of llvm2ice.

Subzero: Build both Debug and Release version of llvm2ice.

Separate objects are built with -O0 and -O2.

Separate executables are built:
  build/Release/llvm2ice - Release build
  build/Debug/llvm2ice - Debug build

The executable built depends on whether the DEBUG make variable is set:
  make -f Makefile.standalone
  make -f Makefile.standalone DEBUG=1
The llvm2ice file in the top-level directory is always removed and symlinked to the appropriate build.

BUG= none
R=jvoung@chromium.org

Committed: https://gerrit.chromium.org/gerrit/gitweb?p=native_client/pnacl-subzero.git;a=commit;h=fddef2419475fa1dc5bd6c018e053c8843ce09cc

[Jim Stichnoth, 2014-09-26 03:19:54]

stichnot@chromium.org changed reviewers:
+ jvoung@chromium.org, kschimpf@google.com

[Jim Stichnoth, 2014-09-26 03:22:38]

1. Do people object to building debug AND release versions by default?  If so,
should Release be the default, and Debug is only built by "make llvm2ice_dbg"?

2. I'm not super happy with all the duplication in the Makefile.  Any make
experts have better ideas?

[Jim Stichnoth, 2014-09-26 13:15:36]

On 2014/09/26 03:22:38, stichnot wrote:
> 1. Do people object to building debug AND release versions by default?  If so,
> should Release be the default, and Debug is only built by "make llvm2ice_dbg"?

I changed my mind on this and just build the Release version by default.  This
should save a lot of build time, and just remember to "make llvm2ice_dbg" before
trying to step through using the debugger.

[jvoung (off chromium), 2014-09-26 19:15:26]

Sure, sounds okay to build one, and have an option to build the other.

https://codereview.chromium.org/605093002/diff/20001/Makefile.standalone
File Makefile.standalone (right):

https://codereview.chromium.org/605093002/diff/20001/Makefile.standalone#newc...
Makefile.standalone:39: 
Yeah, not sure the best way to dedupe some of this, without say, adding
variables?

Then the variable could control the flags + the choice of build/$(foo)
directory. If you keep the binary name "llvm2ice" in both cases, but stash it
under build/$(foo), that might work? Then make clean would only clean one of
them, etc. and the other scripts would unfortunately need to be changed to find
llvm2ice under the build/$(foo) directory (but the other scripts would have been
testing the default one anyway).

[Jim Stichnoth, 2014-09-27 00:23:16]

https://codereview.chromium.org/605093002/diff/20001/Makefile.standalone
File Makefile.standalone (right):

https://codereview.chromium.org/605093002/diff/20001/Makefile.standalone#newc...
Makefile.standalone:39: 
On 2014/09/26 19:15:25, jvoung wrote:
> Yeah, not sure the best way to dedupe some of this, without say, adding
> variables?
> 
> Then the variable could control the flags + the choice of build/$(foo)
> directory. If you keep the binary name "llvm2ice" in both cases, but stash it
> under build/$(foo), that might work? Then make clean would only clean one of
> them, etc. and the other scripts would unfortunately need to be changed to
find
> llvm2ice under the build/$(foo) directory (but the other scripts would have
been
> testing the default one anyway).

OK, I took the suggestion of linking llvm2ice in build/Debug/ or build/Release/.
 Then, unconditionally, llvm2ice is rm'd from the top-level directory and
symlinked to the appropriate version.  The rm and symlink are done
unconditionally, even if nothing changed.

[jvoung (off chromium), 2014-09-27 01:03:19]

LGTM

[Jim Stichnoth, 2014-09-27 01:53:47]

Committed patchset #3 (id:40001) manually as fddef24 (presubmit successful).