- Add getLSDAEncoding to the PowerPC backend.
- Greatly improve the comments to the getLSDAEncoding method.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93796 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCTargetMachine.cpp b/lib/Target/PowerPC/PPCTargetMachine.cpp
index 8079c6e..c80a530 100644
--- a/lib/Target/PowerPC/PPCTargetMachine.cpp
+++ b/lib/Target/PowerPC/PPCTargetMachine.cpp
@@ -194,4 +194,19 @@
   return false;
 }
 
+/// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are 4-byte,
+/// 8-byte, and target default. The CIE is hard-coded to indicate that the LSDA
+/// pointer in the FDE section is an "sdata4", and should be encoded as a 4-byte
+/// pointer by default. However, some systems may require a different size due
+/// to bugs or other conditions. We will default to a 4-byte encoding unless the
+/// system tells us otherwise.
+///
+/// FIXME: This call-back isn't good! We should be using the correct encoding
+/// regardless of the system. However, there are some systems which have bugs
+/// that prevent this from occuring.
+DwarfLSDAEncoding::Encoding PPCTargetMachine::getLSDAEncoding() const {
+  if (Subtarget.isDarwin() && Subtarget.getDarwinVers() != 10)
+    return DwarfLSDAEncoding::Default;
 
+  return DwarfLSDAEncoding::EightByte;
+}