Reapply 79977.
Use MDNodes to encode debug info in llvm IR.

llvm-svn: 80406
diff --git a/llvm/lib/VMCore/AutoUpgrade.cpp b/llvm/lib/VMCore/AutoUpgrade.cpp
index e4c0d1a..3f23b8d 100644
--- a/llvm/lib/VMCore/AutoUpgrade.cpp
+++ b/llvm/lib/VMCore/AutoUpgrade.cpp
@@ -16,8 +16,7 @@
 #include "llvm/Function.h"
 #include "llvm/LLVMContext.h"
 #include "llvm/Module.h"
-#include "llvm/Instructions.h"
-#include "llvm/Intrinsics.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <cstring>
@@ -434,3 +433,74 @@
     }
   }
 }
+
+/// This function checks debug info intrinsics. If an intrinsic is invalid
+/// then this function simply removes the intrinsic. 
+void llvm::CheckDebugInfoIntrinsics(Module *M) {
+
+
+  if (Function *FuncStart = M->getFunction("llvm.dbg.func.start")) {
+    if (!FuncStart->use_empty()) {
+      DbgFuncStartInst *DFSI = cast<DbgFuncStartInst>(FuncStart->use_back());
+      if (!isa<MDNode>(DFSI->getOperand(1))) {
+        while (!FuncStart->use_empty()) {
+          CallInst *CI = cast<CallInst>(FuncStart->use_back());
+          CI->eraseFromParent();
+        }
+        FuncStart->eraseFromParent();
+      }
+    }
+  }
+
+  if (Function *StopPoint = M->getFunction("llvm.dbg.stoppoint")) {
+    if (!StopPoint->use_empty()) {
+      DbgStopPointInst *DSPI = cast<DbgStopPointInst>(StopPoint->use_back());
+      if (!isa<MDNode>(DSPI->getOperand(3))) {
+        while (!StopPoint->use_empty()) {
+          CallInst *CI = cast<CallInst>(StopPoint->use_back());
+          CI->eraseFromParent();
+        }
+        StopPoint->eraseFromParent();
+      }
+    }
+  }
+
+  if (Function *RegionStart = M->getFunction("llvm.dbg.region.start")) {
+    if (!RegionStart->use_empty()) {
+      DbgRegionStartInst *DRSI = cast<DbgRegionStartInst>(RegionStart->use_back());
+      if (!isa<MDNode>(DRSI->getOperand(1))) {
+        while (!RegionStart->use_empty()) {
+          CallInst *CI = cast<CallInst>(RegionStart->use_back());
+          CI->eraseFromParent();
+        }
+        RegionStart->eraseFromParent();
+      }
+    }
+  }
+
+  if (Function *RegionEnd = M->getFunction("llvm.dbg.region.end")) {
+    if (!RegionEnd->use_empty()) {
+      DbgRegionEndInst *DREI = cast<DbgRegionEndInst>(RegionEnd->use_back());
+      if (!isa<MDNode>(DREI->getOperand(1))) {
+        while (!RegionEnd->use_empty()) {
+          CallInst *CI = cast<CallInst>(RegionEnd->use_back());
+          CI->eraseFromParent();
+      }
+        RegionEnd->eraseFromParent();
+      }
+    }
+  }
+  
+  if (Function *Declare = M->getFunction("llvm.dbg.declare")) {
+    if (!Declare->use_empty()) {
+      DbgDeclareInst *DDI = cast<DbgDeclareInst>(Declare->use_back());
+      if (!isa<MDNode>(DDI->getOperand(2))) {
+        while (!Declare->use_empty()) {
+          CallInst *CI = cast<CallInst>(Declare->use_back());
+          CI->eraseFromParent();
+        }
+        Declare->eraseFromParent();
+      }
+    }
+  }
+}