diff --git a/include/llvm/CodeGen/DwarfWriter.h b/include/llvm/CodeGen/DwarfWriter.h
index 7c9ada8..1616dfa 100644
--- a/include/llvm/CodeGen/DwarfWriter.h
+++ b/include/llvm/CodeGen/DwarfWriter.h
@@ -29,6 +29,7 @@
 class DwarfException;
 class MachineModuleInfo;
 class MachineFunction;
+class Value;
 class Module;
 class GlobalVariable;
 class TargetAsmInfo;
@@ -75,6 +76,8 @@
   ///
   void EndFunction(MachineFunction *MF);
 
+  /// ValidDebugInfo - Return true if V represents valid debug info value.
+  bool ValidDebugInfo(Value *V);
 
   /// label. Returns a unique label ID used to generate a label and provide
   /// correspondence to the source line list.
diff --git a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
index 02f27d1..f3ad9aa 100644
--- a/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfWriter.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/UniqueVector.h"
 #include "llvm/Module.h"
 #include "llvm/DerivedTypes.h"
+#include "llvm/Constants.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
@@ -100,6 +101,25 @@
     getGlobalVariablesUsing(UseRoot, Result);
 }
 
+/// getGlobalVariable - Return either a direct or cast Global value.
+///
+static GlobalVariable *getGlobalVariable(Value *V) {
+  if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
+    return GV;
+  } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
+    if (CE->getOpcode() == Instruction::BitCast) {
+      return dyn_cast<GlobalVariable>(CE->getOperand(0));
+    } else if (CE->getOpcode() == Instruction::GetElementPtr) {
+      for (unsigned int i=1; i<CE->getNumOperands(); i++) {
+        if (!CE->getOperand(i)->isNullValue())
+          return NULL;
+      }
+      return dyn_cast<GlobalVariable>(CE->getOperand(0));
+    }
+  }
+  return NULL;
+}
+
 //===----------------------------------------------------------------------===//
 /// DWLabel - Labels are used to track locations in the assembler file.
 /// Labels appear in the form @verbatim <prefix><Tag><Number> @endverbatim,
@@ -3056,6 +3076,26 @@
 
 public:
 
+  /// ValidDebugInfo - Return true if V represents valid debug info value.
+  bool ValidDebugInfo(Value *V) {
+    GlobalVariable *GV = getGlobalVariable(V);
+    if (!GV)
+      return false;
+    
+    if (GV->getLinkage() != GlobalValue::InternalLinkage
+        && GV->getLinkage() != GlobalValue::LinkOnceLinkage)
+      return false;
+
+    DIDescriptor DI(GV);
+    // Check current version. Allow Version6 for now.
+    unsigned Version = DI.getVersion();
+    if (Version != DIDescriptor::Version7 && Version != DIDescriptor::Version6)
+      return false;
+
+    //FIXME - Check individual descriptors.
+    return true;
+  }
+
   /// RecordSourceLine - Records location information and associates it with a 
   /// label. Returns a unique label ID used to generate a label and provide
   /// correspondence to the source line list.
@@ -4221,6 +4261,11 @@
     MMI->EndFunction();
 }
 
+/// ValidDebugInfo - Return true if V represents valid debug info value.
+bool DwarfWriter::ValidDebugInfo(Value *V) {
+  return DD->ValidDebugInfo(V);
+}
+
 /// RecordSourceLine - Records location information and associates it with a 
 /// label. Returns a unique label ID used to generate a label and provide
 /// correspondence to the source line list.
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 5dd0afb..d797d90 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -317,7 +317,7 @@
   default: break;
   case Intrinsic::dbg_stoppoint: {
     DbgStopPointInst *SPI = cast<DbgStopPointInst>(I);
-    if (DW && SPI->getContext()) {
+    if (DW && SPI->getContext() && DW->ValidDebugInfo(SPI->getContext())) {
       DICompileUnit CU(cast<GlobalVariable>(SPI->getContext()));
       unsigned SrcFile = DW->RecordSource(CU.getDirectory(),
                                           CU.getFilename());
@@ -331,7 +331,7 @@
   }
   case Intrinsic::dbg_region_start: {
     DbgRegionStartInst *RSI = cast<DbgRegionStartInst>(I);
-    if (DW && RSI->getContext()) {
+    if (DW && RSI->getContext() && DW->ValidDebugInfo(RSI->getContext())) {
       unsigned ID = 
         DW->RecordRegionStart(cast<GlobalVariable>(RSI->getContext()));
       const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
@@ -341,7 +341,7 @@
   }
   case Intrinsic::dbg_region_end: {
     DbgRegionEndInst *REI = cast<DbgRegionEndInst>(I);
-    if (DW && REI->getContext()) {
+    if (DW && REI->getContext() && DW->ValidDebugInfo(REI->getContext())) {
       unsigned ID = 
         DW->RecordRegionEnd(cast<GlobalVariable>(REI->getContext()));
       const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
@@ -353,7 +353,7 @@
     if (!DW) return true;
     DbgFuncStartInst *FSI = cast<DbgFuncStartInst>(I);
     Value *SP = FSI->getSubprogram();
-    if (SP) {
+    if (SP && DW->ValidDebugInfo(SP)) {
       // llvm.dbg.func.start implicitly defines a dbg_stoppoint which is
       // what (most?) gdb expects.
       DISubprogram Subprogram(cast<GlobalVariable>(SP));
@@ -375,7 +375,7 @@
   case Intrinsic::dbg_declare: {
     DbgDeclareInst *DI = cast<DbgDeclareInst>(I);
     Value *Variable = DI->getVariable();
-    if (DW && Variable) {
+    if (DW && Variable && DW->ValidDebugInfo(Variable)) {
       // Determine the address of the declared object.
       Value *Address = DI->getAddress();
       if (BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index 49b7ad8..241ad00 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -3746,7 +3746,7 @@
   case Intrinsic::dbg_stoppoint: {
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgStopPointInst &SPI = cast<DbgStopPointInst>(I);
-    if (DW && SPI.getContext())
+    if (DW && SPI.getContext() && DW->ValidDebugInfo(SPI.getContext()))
       DAG.setRoot(DAG.getDbgStopPoint(getRoot(),
                                       SPI.getLine(),
                                       SPI.getColumn(),
@@ -3756,7 +3756,7 @@
   case Intrinsic::dbg_region_start: {
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgRegionStartInst &RSI = cast<DbgRegionStartInst>(I);
-    if (DW && RSI.getContext()) {
+    if (DW && RSI.getContext() && DW->ValidDebugInfo(RSI.getContext())) {
       unsigned LabelID = 
         DW->RecordRegionStart(cast<GlobalVariable>(RSI.getContext()));
       DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getRoot(), LabelID));
@@ -3767,7 +3767,7 @@
   case Intrinsic::dbg_region_end: {
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgRegionEndInst &REI = cast<DbgRegionEndInst>(I);
-    if (DW && REI.getContext()) {
+    if (DW && REI.getContext() && DW->ValidDebugInfo(REI.getContext())) {
       unsigned LabelID = 
         DW->RecordRegionEnd(cast<GlobalVariable>(REI.getContext()));
       DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getRoot(), LabelID));
@@ -3780,7 +3780,7 @@
     if (!DW) return 0;
     DbgFuncStartInst &FSI = cast<DbgFuncStartInst>(I);
     Value *SP = FSI.getSubprogram();
-    if (SP) {
+    if (SP && DW->ValidDebugInfo(SP)) {
       // llvm.dbg.func.start implicitly defines a dbg_stoppoint which is
       // what (most?) gdb expects.
       DISubprogram Subprogram(cast<GlobalVariable>(SP));
@@ -3802,7 +3802,7 @@
     DwarfWriter *DW = DAG.getDwarfWriter();
     DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
     Value *Variable = DI.getVariable();
-    if (DW && Variable)
+    if (DW && Variable && DW->ValidDebugInfo(Variable))
       DAG.setRoot(DAG.getNode(ISD::DECLARE, MVT::Other, getRoot(),
                               getValue(DI.getAddress()), getValue(Variable)));
     return 0;
diff --git a/test/DebugInfo/2009-01-15-dbg_declare.ll b/test/DebugInfo/2009-01-15-dbg_declare.ll
new file mode 100644
index 0000000..475949a
--- /dev/null
+++ b/test/DebugInfo/2009-01-15-dbg_declare.ll
@@ -0,0 +1,15 @@
+
+; RUN: llvm-as < %s | llc -f -o /dev/null
+target triple = "powerpc-apple-darwin9.5"
+        %llvm.dbg.variable.type = type { i32, { }*, i8*, { }*, i32, { }*, i8*, i8* }
+@llvm.dbg.variable24 = external constant %llvm.dbg.variable.type                ; <%llvm.dbg.variable.type*> [#uses=1]
+
+declare void @llvm.dbg.declare({ }*, { }*) nounwind
+
+define i32 @isascii(i32 %_c) nounwind {
+entry:
+        call void @llvm.dbg.declare({ }* null, { }* bitcast (%llvm.dbg.variable.type* @llvm.dbg.variable24 to { }*))
+        unreachable
+}
+
+