Track the compact unwind encoding for when we are unable to generate compact unwind information.

Compact unwind has an encoding for when we're not able to generate compact
unwind and must generate an EH frame instead. Track that, but still emit that CU
encoding.

llvm-svn: 179220

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index d19e79ac64f..79ebad15e67 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -145,12 +145,16 @@ void MCObjectFileInfo::InitMachOMCObjectFileInfo(Triple T) {
   LSDASection = Ctx->getMachOSection("__TEXT", "__gcc_except_tab", 0,
                                      SectionKind::getReadOnlyWithRel());
 
-  if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6))
+  if (T.isMacOSX() && !T.isMacOSXVersionLT(10, 6)) {
     CompactUnwindSection =
       Ctx->getMachOSection("__LD", "__compact_unwind",
                            MCSectionMachO::S_ATTR_DEBUG,
                            SectionKind::getReadOnly());
 
+    if (T.getArch() == Triple::x86_64 || T.getArch() == Triple::x86)
+      CompactUnwindDwarfEHFrameOnly = 0x04000000;
+  }
+
   // Debug Information.
   DwarfAccelNamesSection =
     Ctx->getMachOSection("__DWARF", "__apple_names",
@@ -629,6 +633,8 @@ void MCObjectFileInfo::InitMCObjectFileInfo(StringRef TT, Reloc::Model relocm,
   PersonalityEncoding = LSDAEncoding = FDEEncoding = FDECFIEncoding =
     TTypeEncoding = dwarf::DW_EH_PE_absptr;
 
+  CompactUnwindDwarfEHFrameOnly = 0;
+
   EHFrameSection = 0;             // Created on demand.
   CompactUnwindSection = 0;       // Used only by selected targets.
   DwarfAccelNamesSection = 0;     // Used only by selected targets.