[PATCH] clang-cl: Support the /link option and hard-code the target triple

[Hans Wennborg]

================
Comment at: lib/Driver/Driver.cpp:339
@@ -338,1 +338,3 @@
+  if (IsCLMode())
+    DefaultTargetTriple = "i686-pc-win32";
   if (const Arg *A = Args->getLastArg(options::OPT_target))
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Reid Kleckner wrote:
> This should take the existing default target triple and just override the OS and vendor.  The ISA should probably match however clang-cl was built.  The LLVM Triple class should make it easy to do that and round trip it back to a string, since that's what we have here currently.  Or for extra bonus points you can make DefaultTargetTriple an actual Triple.
Done. (I kept DefaultTargetTriple as a string, adding converting it to the list of potential cleanups.)

================
Comment at: lib/Driver/Tools.cpp:6596
@@ -6595,2 +6595,3 @@
   Args.AddAllArgValues(CmdArgs, options::OPT_l);
+  Args.AddAllArgValues(CmdArgs, options::OPT__SLASH_link);
 
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Reid Kleckner wrote:
> Can you make sure we forward -Wl, in non-cl mode, or just add a FIXME?  I seem to recall problems with it the other day.
Yes, it seems we don't forward -Wl et al. I've added a FIXME.


http://llvm-reviews.chandlerc.com/D1388

COMMIT
  http://llvm-reviews.chandlerc.com/rL188331