Revert "Revert r189902 as the workaround shouldn't be necessary anymore."

Needs testcase updates.

llvm-svn: 190000

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 535b094f168..6835f40cd8e 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -161,8 +161,12 @@ DIType DbgVariable::getType() const {
 /// Return Dwarf Version by checking module flags.
 static unsigned getDwarfVersionFromModule(const Module *M) {
   Value *Val = M->getModuleFlag("Dwarf Version");
+  // If we don't have a value in the module go ahead and use the default in
+  // dwarf::DWARF_VERSION.
+  // FIXME: Apple ld has a problem parsing compilation units that specify a
+  // dwarf version of greater than 3.
   if (!Val)
-    return dwarf::DWARF_VERSION;
+    return Triple(M->getTargetTriple()).isOSDarwin() ? 3 : dwarf::DWARF_VERSION;
   return cast<ConstantInt>(Val)->getZExtValue();
 }