- Add a comment to the callback indicating that it's *extremely* not a good

idea, but unfortunately necessary.
- Default to using 4-bytes for the LSDA pointer encoding to agree with the
  encoded value in the CIE.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93753 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Target/TargetMachine.h

@@ -202,6 +202,9 @@ public:
 
   /// getLSDAEncoding - Returns the LSDA pointer encoding. The choices are
   /// 4-byte, 8-byte, and target default.
+  /// 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 {
     return DwarfLSDAEncoding::Default;
   }

lib/CodeGen/AsmPrinter/DwarfException.cpp

@@ -283,7 +283,7 @@ void DwarfException::EmitFDE(const FunctionEHFrameInfo &EHFrameInfo) {
     if (MMI->getPersonalities()[0] != NULL) {
       bool is4Byte = TD->getPointerSize() == sizeof(int32_t);
 
-      if (Asm->TM.getLSDAEncoding() == DwarfLSDAEncoding::FourByte) {
+      if (Asm->TM.getLSDAEncoding() != DwarfLSDAEncoding::EightByte) {
         Asm->EmitULEB128Bytes(4);
         Asm->EOL("Augmentation size");
 

lib/Target/X86/X86TargetMachine.cpp

@@ -251,8 +251,8 @@ void X86TargetMachine::setCodeModelForJIT() {
 }
 
 DwarfLSDAEncoding::Encoding X86TargetMachine::getLSDAEncoding() const {
-  if (Subtarget.isTargetDarwin() && Subtarget.getDarwinVers() > 10)
+  if (Subtarget.isTargetDarwin() && Subtarget.getDarwinVers() != 10)
     return DwarfLSDAEncoding::FourByte;
 
-  return DwarfLSDAEncoding::Default;
+  return DwarfLSDAEncoding::EightByte;
 }