PNaCl: Build a PPAPI shims library for all architectures

PNaCl: Build a PPAPI shims library on all architectures

Before, the shims library was only built on x86-64.  We change it to
build on x86-32 and ARM too, where we define _pnacl_wrapper_start() to
be a trivial wrapper which immediately calls the user code's _start()
function.

This will mean we won't need an conditional for x86-64 in the
translators.

Since Gyp doesn't allow files to be excluded per architecture, I've
put #ifdefs into shim_ppapi.c and pnacl_shim.c.

BUG=http://code.google.com/p/nativeclient/issues/detail?id=3018
TEST=I checked that libpnacl_irt_shim.a builds OK in Scons

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=158121

[jvoung (off chromium), 2012-09-20 01:06:36]

http://codereview.chromium.org/10950042/diff/1/ppapi/generators/idl_gen_wrapp...
File ppapi/generators/idl_gen_wrapper.py (right):

http://codereview.chromium.org/10950042/diff/1/ppapi/generators/idl_gen_wrapp...
ppapi/generators/idl_gen_wrapper.py:433: out.Write('\n/* The PNaCl PPAPI shims
are only needed on x86-64. */\n')
Hmm idl_gen_wrapper was actually meant to be for any kind of PPB/PPP wrapping
(e.g., if you want to instrument the calls), though nobody is really using it.  
idl_gen_pnacl specializes it for pnacl.

[Mark Seaborn, 2012-09-20 03:56:24]

http://codereview.chromium.org/10950042/diff/1/ppapi/generators/idl_gen_wrapp...
File ppapi/generators/idl_gen_wrapper.py (right):

http://codereview.chromium.org/10950042/diff/1/ppapi/generators/idl_gen_wrapp...
ppapi/generators/idl_gen_wrapper.py:433: out.Write('\n/* The PNaCl PPAPI shims
are only needed on x86-64. */\n')
On 2012/09/20 01:06:36, jvoung (chromium) wrote:
> Hmm idl_gen_wrapper was actually meant to be for any kind of
> PPB/PPP wrapping (e.g., if you want to instrument the calls),

OK, I've split it into two parts.

> though nobody is really using it.

Yeah, I noticed. :-)  It did seem to be premature generalisation.

[jvoung (off chromium), 2012-09-20 15:13:48]

Lgtm

http://codereview.chromium.org/10950042/diff/1/ppapi/generators/idl_gen_wrapp...
File ppapi/generators/idl_gen_wrapper.py (right):

http://codereview.chromium.org/10950042/diff/1/ppapi/generators/idl_gen_wrapp...
ppapi/generators/idl_gen_wrapper.py:433: out.Write('\n/* The PNaCl PPAPI shims
are only needed on x86-64. */\n')
On 2012/09/20 03:56:24, Mark Seaborn wrote:
> On 2012/09/20 01:06:36, jvoung (chromium) wrote:
> > Hmm idl_gen_wrapper was actually meant to be for any kind of
> > PPB/PPP wrapping (e.g., if you want to instrument the calls),
> 
> OK, I've split it into two parts.
> 
> > though nobody is really using it.
> 
> Yeah, I noticed. :-)  It did seem to be premature generalisation.

Well there was an email thread about using something like this to check test
coverage of the interfaces at the time I wrote it, but yeah it might not be the
right abstractions anyway.  Thanks for keeping the split.

[Mark Seaborn, 2012-09-20 16:28:35]

+sehr: I need an OWNERS review for ppapi/generators

[Mark Seaborn, 2012-09-21 18:26:38]

+brettw: Can you sign off on this as an OWNER of ppapi/generators, please?

[sehr (please use chromium), 2012-09-21 23:11:39]

lgtm