Fix bug 19437 - Only add discriminators for DWARF 4 and above.

Summary:
This prevents the discriminator generation pass from triggering if
the DWARF version being used in the module is prior to 4.

Reviewers: echristo, dblaikie

CC: llvm-commits

Differential Revision: http://reviews.llvm.org/D3413

llvm-svn: 206507

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/IR/Module.cpp b/llvm/lib/IR/Module.cpp
index 43f42bc..5dbed69c 100644
--- a/llvm/lib/IR/Module.cpp
+++ b/llvm/lib/IR/Module.cpp
@@ -23,6 +23,7 @@
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/LeakDetector.h"
+#include "llvm/Support/Dwarf.h"
 #include <algorithm>
 #include <cstdarg>
 #include <cstdlib>
@@ -429,3 +430,10 @@ void Module::dropAllReferences() {
   for(Module::alias_iterator I = alias_begin(), E = alias_end(); I != E; ++I)
     I->dropAllReferences();
 }
+
+unsigned Module::getDwarfVersion() const {
+  Value *Val = getModuleFlag("Dwarf Version");
+  if (!Val)
+    return dwarf::DWARF_VERSION;
+  return cast<ConstantInt>(Val)->getZExtValue();
+}