[DebugInfo] Added support for Checksum debug info feature.

Differential Revision: https://reviews.llvm.org/D27642

llvm-svn: 290514
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 83edaad..eecef94 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -1408,6 +1408,7 @@
   }
   void printTag(const DINode *N);
   void printMacinfoType(const DIMacroNode *N);
+  void printChecksumKind(const DIFile *N);
   void printString(StringRef Name, StringRef Value,
                    bool ShouldSkipEmpty = true);
   void printMetadata(StringRef Name, const Metadata *MD,
@@ -1441,6 +1442,13 @@
     Out << N->getMacinfoType();
 }
 
+void MDFieldPrinter::printChecksumKind(const DIFile *N) {
+  if (N->getChecksumKind() == DIFile::CSK_None)
+    // Skip CSK_None checksum kind.
+    return;
+  Out << FS << "checksumkind: " << N->getChecksumKindAsString();
+}
+
 void MDFieldPrinter::printString(StringRef Name, StringRef Value,
                                  bool ShouldSkipEmpty) {
   if (ShouldSkipEmpty && Value.empty())
@@ -1653,6 +1661,8 @@
                       /* ShouldSkipEmpty */ false);
   Printer.printString("directory", N->getDirectory(),
                       /* ShouldSkipEmpty */ false);
+  Printer.printChecksumKind(N);
+  Printer.printString("checksum", N->getChecksum(), /* ShouldSkipEmpty */ true);
   Out << ")";
 }