[PATCH] D16788: PS4 ABI Round 2. Actual PS4 code.

[John McCall via cfe-commits]

rjmccall added inline comments.

================
Comment at: include/clang/Basic/TargetCXXABI.h:118
@@ -115,1 +117,3 @@
+    /// in LLVM 3.2.
+    PS4
   };
----------------
I'm not sure why you added a new C++ ABI kind here.  The bug fix you're opting out of is not at all specific to C++, and there are more straightforward ways to check the target than checking the C++ ABI kind.

I mean, I have no doubt that eventually there will be some significant C++ ABI bug fix that you don't want to pick up, so I'm not opposed to adding a new C++ ABI kind.  It just seems inappropriate to do that in this patch.

================
Comment at: lib/AST/RecordLayoutBuilder.cpp:1598-1599
@@ -1597,1 +1597,4 @@
 
+    // PS4 remains compatible to pre r257462 behavior.
+    bool isPS4ABI = (Context.getTargetInfo().getCXXABI().getKind() == TargetCXXABI::PS4);
+
----------------
rsmith wrote:
> Please say what that behavior was here. "The PS4 ABI ignores explicit alignment attributes on bitfields." or similar.
Also, this should be added as a bit on TargetInfo instead of making it a target-specific check in random code.  This also makes it easier to make the code self-documenting, because instead of:

   } else if (ExplicitFieldAlign && !isPS4ABI) {

you'd have

   } else if (ExplicitFieldAlign && Context.getTargetInfo().useExplicitBitFieldAlignment()) {

You can then document the fact that your ABI is explicitly opting out of this bug fix in a comment on the line in Targets.cpp where you set this field to false.


http://reviews.llvm.org/D16788