- Add getLSDAEncoding to the PowerPC backend.

- Greatly improve the comments to the getLSDAEncoding method.

llvm-svn: 93796

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/lib/Target/X86/X86TargetMachine.h b/llvm/lib/Target/X86/X86TargetMachine.h
index c42aa89ff9b..d05bebd0712 100644
--- a/llvm/lib/Target/X86/X86TargetMachine.h
+++ b/llvm/lib/Target/X86/X86TargetMachine.h
@@ -62,6 +62,16 @@ public:
     return Subtarget.isTargetELF() ? &ELFWriterInfo : 0;
   }
 
+  /// 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.
   virtual DwarfLSDAEncoding::Encoding getLSDAEncoding() const;
 
   // Set up the pass pipeline.