Use StringRef (again) in DebugInfo interface.

llvm-svn: 89866

5 files changed, 138 insertions, 134 deletions

diff --git a/llvm/include/llvm/Analysis/DebugInfo.h b/llvm/include/llvm/Analysis/DebugInfo.h
index 89376ed7293..866ed8a8757 100644
--- a/llvm/include/llvm/Analysis/DebugInfo.h
+++ b/llvm/include/llvm/Analysis/DebugInfo.h
@@ -55,7 +55,7 @@ namespace llvm {
     /// not, the debug info is corrupt and we ignore it.
     DIDescriptor(MDNode *N, unsigned RequiredTag);
 
-    const char *getStringField(unsigned Elt) const;
+    StringRef getStringField(unsigned Elt) const;
     unsigned getUnsignedField(unsigned Elt) const {
       return (unsigned)getUInt64Field(Elt);
     }
@@ -137,8 +137,8 @@ namespace llvm {
     }
     virtual ~DIScope() {}
 
-    const char *getFilename() const;
-    const char *getDirectory() const;
+    StringRef getFilename() const;
+    StringRef getDirectory() const;
   };
 
   /// DICompileUnit - A wrapper for a compile unit.
@@ -150,9 +150,9 @@ namespace llvm {
     }
 
     unsigned getLanguage() const     { return getUnsignedField(2); }
-    const char *getFilename() const  { return getStringField(3);   }
-    const char *getDirectory() const { return getStringField(4);   }
-    const char *getProducer() const  { return getStringField(5);   }
+    StringRef getFilename() const  { return getStringField(3);   }
+    StringRef getDirectory() const { return getStringField(4);   }
+    StringRef getProducer() const  { return getStringField(5);   }
 
     /// isMain - Each input file is encoded as a separate compile unit in LLVM
     /// debugging information output. However, many target specific tool chains
@@ -165,7 +165,7 @@ namespace llvm {
 
     bool isMain() const                { return getUnsignedField(6); }
     bool isOptimized() const           { return getUnsignedField(7); }
-    const char *getFlags() const       { return getStringField(8);   }
+    StringRef getFlags() const       { return getStringField(8);   }
     unsigned getRunTimeVersion() const { return getUnsignedField(9); }
 
     /// Verify - Verify that a compile unit is well formed.
@@ -183,7 +183,7 @@ namespace llvm {
     explicit DIEnumerator(MDNode *N = 0)
       : DIDescriptor(N, dwarf::DW_TAG_enumerator) {}
 
-    const char *getName() const        { return getStringField(1); }
+    StringRef getName() const        { return getStringField(1); }
     uint64_t getEnumValue() const      { return getUInt64Field(2); }
   };
 
@@ -217,7 +217,7 @@ namespace llvm {
     virtual ~DIType() {}
 
     DIDescriptor getContext() const     { return getDescriptorField(1); }
-    const char *getName() const         { return getStringField(2);     }
+    StringRef getName() const         { return getStringField(2);     }
     DICompileUnit getCompileUnit() const{ return getFieldAs<DICompileUnit>(3); }
     unsigned getLineNumber() const      { return getUnsignedField(4); }
     uint64_t getSizeInBits() const      { return getUInt64Field(5); }
@@ -317,9 +317,9 @@ namespace llvm {
     virtual ~DIGlobal() {}
 
     DIDescriptor getContext() const     { return getDescriptorField(2); }
-    const char *getName() const         { return getStringField(3); }
-    const char *getDisplayName() const  { return getStringField(4); }
-    const char *getLinkageName() const  { return getStringField(5); }
+    StringRef getName() const         { return getStringField(3); }
+    StringRef getDisplayName() const  { return getStringField(4); }
+    StringRef getLinkageName() const  { return getStringField(5); }
     DICompileUnit getCompileUnit() const{ return getFieldAs<DICompileUnit>(6); }
     unsigned getLineNumber() const      { return getUnsignedField(7); }
     DIType getType() const              { return getFieldAs<DIType>(8); }
@@ -342,16 +342,16 @@ namespace llvm {
     }
 
     DIDescriptor getContext() const     { return getDescriptorField(2); }
-    const char *getName() const         { return getStringField(3); }
-    const char *getDisplayName() const  { return getStringField(4); }
-    const char *getLinkageName() const  { return getStringField(5); }
+    StringRef getName() const         { return getStringField(3); }
+    StringRef getDisplayName() const  { return getStringField(4); }
+    StringRef getLinkageName() const  { return getStringField(5); }
     DICompileUnit getCompileUnit() const{ return getFieldAs<DICompileUnit>(6); }
     unsigned getLineNumber() const      { return getUnsignedField(7); }
     DICompositeType getType() const { return getFieldAs<DICompositeType>(8); }
 
     /// getReturnTypeName - Subprogram return types are encoded either as
     /// DIType or as DICompositeType.
-    const char *getReturnTypeName() const {
+    StringRef getReturnTypeName() const {
       DICompositeType DCT(getFieldAs<DICompositeType>(8));
       if (!DCT.isNull()) {
         DIArray A = DCT.getTypeArray();
@@ -366,8 +366,8 @@ namespace llvm {
     /// compile unit, like 'static' in C.
     unsigned isLocalToUnit() const     { return getUnsignedField(9); }
     unsigned isDefinition() const      { return getUnsignedField(10); }
-    const char *getFilename() const    { return getCompileUnit().getFilename();}
-    const char *getDirectory() const   { return getCompileUnit().getDirectory();}
+    StringRef getFilename() const    { return getCompileUnit().getFilename();}
+    StringRef getDirectory() const   { return getCompileUnit().getDirectory();}
 
     /// Verify - Verify that a subprogram descriptor is well formed.
     bool Verify() const;
@@ -406,7 +406,7 @@ namespace llvm {
     }
 
     DIDescriptor getContext() const { return getDescriptorField(1); }
-    const char *getName() const     { return getStringField(2);     }
+    StringRef getName() const     { return getStringField(2);     }
     DICompileUnit getCompileUnit() const{ return getFieldAs<DICompileUnit>(3); }
     unsigned getLineNumber() const      { return getUnsignedField(4); }
     DIType getType() const              { return getFieldAs<DIType>(5); }
@@ -444,8 +444,8 @@ namespace llvm {
         DbgNode = 0;
     }
     DIScope getContext() const       { return getFieldAs<DIScope>(1); }
-    const char *getDirectory() const { return getContext().getDirectory(); }
-    const char *getFilename() const  { return getContext().getFilename(); }
+    StringRef getDirectory() const { return getContext().getDirectory(); }
+    StringRef getFilename() const  { return getContext().getFilename(); }
   };
 
   /// DILocation - This object holds location information. This object
@@ -458,8 +458,8 @@ namespace llvm {
     unsigned getColumnNumber() const   { return getUnsignedField(1); }
     DIScope  getScope() const          { return getFieldAs<DIScope>(2); }
     DILocation getOrigLocation() const { return getFieldAs<DILocation>(3); }
-    const char *getFilename() const    { return getScope().getFilename(); }
-    const char *getDirectory() const   { return getScope().getDirectory(); }
+    StringRef getFilename() const    { return getScope().getFilename(); }
+    StringRef getDirectory() const   { return getScope().getDirectory(); }
   };
 
   /// DIFactory - This object assists with the construction of the various
@@ -489,26 +489,26 @@ namespace llvm {
     /// CreateCompileUnit - Create a new descriptor for the specified compile
     /// unit.
     DICompileUnit CreateCompileUnit(unsigned LangID,
-                                    const char * Filename,
-                                    const char * Directory,
-                                    const char * Producer,
+                                    StringRef Filename,
+                                    StringRef Directory,
+                                    StringRef Producer,
                                     bool isMain = false,
                                     bool isOptimized = false,
-                                    const char *Flags = "",
+                                    StringRef Flags = "",
                                     unsigned RunTimeVer = 0);
 
     /// CreateEnumerator - Create a single enumerator value.
-    DIEnumerator CreateEnumerator(const char * Name, uint64_t Val);
+    DIEnumerator CreateEnumerator(StringRef Name, uint64_t Val);
 
     /// CreateBasicType - Create a basic type like int, float, etc.
-    DIBasicType CreateBasicType(DIDescriptor Context, const char * Name,
+    DIBasicType CreateBasicType(DIDescriptor Context, StringRef Name,
                                 DICompileUnit CompileUnit, unsigned LineNumber,
                                 uint64_t SizeInBits, uint64_t AlignInBits,
                                 uint64_t OffsetInBits, unsigned Flags,
                                 unsigned Encoding);
 
     /// CreateBasicType - Create a basic type like int, float, etc.
-    DIBasicType CreateBasicTypeEx(DIDescriptor Context, const char * Name,
+    DIBasicType CreateBasicTypeEx(DIDescriptor Context, StringRef Name,
                                 DICompileUnit CompileUnit, unsigned LineNumber,
                                 Constant *SizeInBits, Constant *AlignInBits,
                                 Constant *OffsetInBits, unsigned Flags,
@@ -517,7 +517,7 @@ namespace llvm {
     /// CreateDerivedType - Create a derived type like const qualified type,
     /// pointer, typedef, etc.
     DIDerivedType CreateDerivedType(unsigned Tag, DIDescriptor Context,
-                                    const char * Name,
+                                    StringRef Name,
                                     DICompileUnit CompileUnit,
                                     unsigned LineNumber,
                                     uint64_t SizeInBits, uint64_t AlignInBits,
@@ -527,7 +527,7 @@ namespace llvm {
     /// CreateDerivedType - Create a derived type like const qualified type,
     /// pointer, typedef, etc.
     DIDerivedType CreateDerivedTypeEx(unsigned Tag, DIDescriptor Context,
-                                        const char * Name,
+                                        StringRef Name,
                                     DICompileUnit CompileUnit,
                                     unsigned LineNumber,
                                     Constant *SizeInBits, Constant *AlignInBits,
@@ -536,7 +536,7 @@ namespace llvm {
 
     /// CreateCompositeType - Create a composite type like array, struct, etc.
     DICompositeType CreateCompositeType(unsigned Tag, DIDescriptor Context,
-                                        const char * Name,
+                                        StringRef Name,
                                         DICompileUnit CompileUnit,
                                         unsigned LineNumber,
                                         uint64_t SizeInBits,
@@ -548,7 +548,7 @@ namespace llvm {
 
     /// CreateCompositeType - Create a composite type like array, struct, etc.
     DICompositeType CreateCompositeTypeEx(unsigned Tag, DIDescriptor Context,
-                                        const char * Name,
+                                        StringRef Name,
                                         DICompileUnit CompileUnit,
                                         unsigned LineNumber,
                                         Constant *SizeInBits,
@@ -560,25 +560,25 @@ namespace llvm {
 
     /// CreateSubprogram - Create a new descriptor for the specified subprogram.
     /// See comments in DISubprogram for descriptions of these fields.
-    DISubprogram CreateSubprogram(DIDescriptor Context, const char * Name,
-                                  const char * DisplayName,
-                                  const char * LinkageName,
+    DISubprogram CreateSubprogram(DIDescriptor Context, StringRef Name,
+                                  StringRef DisplayName,
+                                  StringRef LinkageName,
                                   DICompileUnit CompileUnit, unsigned LineNo,
                                   DIType Type, bool isLocalToUnit,
                                   bool isDefinition);
 
     /// CreateGlobalVariable - Create a new descriptor for the specified global.
     DIGlobalVariable
-    CreateGlobalVariable(DIDescriptor Context, const char * Name,
-                         const char * DisplayName,
-                         const char * LinkageName,
+    CreateGlobalVariable(DIDescriptor Context, StringRef Name,
+                         StringRef DisplayName,
+                         StringRef LinkageName,
                          DICompileUnit CompileUnit,
                          unsigned LineNo, DIType Type, bool isLocalToUnit,
                          bool isDefinition, llvm::GlobalVariable *GV);
 
     /// CreateVariable - Create a new descriptor for the specified variable.
     DIVariable CreateVariable(unsigned Tag, DIDescriptor Context,
-                              const char * Name,
+                              StringRef Name,
                               DICompileUnit CompileUnit, unsigned LineNo,
                               DIType Type);
 
diff --git a/llvm/lib/Analysis/DebugInfo.cpp b/llvm/lib/Analysis/DebugInfo.cpp
index 5311f99e01c..41d803c699d 100644
--- a/llvm/lib/Analysis/DebugInfo.cpp
+++ b/llvm/lib/Analysis/DebugInfo.cpp
@@ -78,19 +78,16 @@ DIDescriptor::DIDescriptor(MDNode *N, unsigned RequiredTag) {
   }
 }
 
-const char *
+StringRef 
 DIDescriptor::getStringField(unsigned Elt) const {
   if (DbgNode == 0)
-    return NULL;
+    return StringRef();
 
   if (Elt < DbgNode->getNumElements())
-    if (MDString *MDS = dyn_cast_or_null<MDString>(DbgNode->getElement(Elt))) {
-      if (MDS->getLength() == 0)
-        return NULL;
-      return MDS->getString().data();
-    }
+    if (MDString *MDS = dyn_cast_or_null<MDString>(DbgNode->getElement(Elt)))
+      return MDS->getString();
 
-  return NULL;
+  return StringRef();
 }
 
 uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
@@ -310,8 +307,8 @@ void DIDerivedType::replaceAllUsesWith(DIDescriptor &D) {
 bool DICompileUnit::Verify() const {
   if (isNull())
     return false;
-  const char *N = getFilename();
-  if (!N)
+  StringRef N = getFilename();
+  if (N.empty())
     return false;
   // It is possible that directory and produce string is empty.
   return true;
@@ -366,7 +363,7 @@ bool DIGlobalVariable::Verify() const {
   if (isNull())
     return false;
 
-  if (!getDisplayName())
+  if (getDisplayName().empty())
     return false;
 
   if (getContext().isNull())
@@ -426,15 +423,15 @@ uint64_t DIDerivedType::getOriginalTypeSize() const {
 /// information for the function F.
 bool DISubprogram::describes(const Function *F) {
   assert (F && "Invalid function");
-  const char *Name = getLinkageName();
-  if (!Name)
+  StringRef Name = getLinkageName();
+  if (Name.empty())
     Name = getName();
-  if (strcmp(F->getName().data(), Name) == 0)
+  if (F->getName() == Name)
     return true;
   return false;
 }
 
-const char *DIScope::getFilename() const {
+StringRef DIScope::getFilename() const {
   if (isLexicalBlock()) 
     return DILexicalBlock(DbgNode).getFilename();
   else if (isSubprogram())
@@ -443,10 +440,10 @@ const char *DIScope::getFilename() const {
     return DICompileUnit(DbgNode).getFilename();
   else 
     assert (0 && "Invalid DIScope!");
-  return NULL;
+  return StringRef();
 }
 
-const char *DIScope::getDirectory() const {
+StringRef DIScope::getDirectory() const {
   if (isLexicalBlock()) 
     return DILexicalBlock(DbgNode).getDirectory();
   else if (isSubprogram())
@@ -455,7 +452,7 @@ const char *DIScope::getDirectory() const {
     return DICompileUnit(DbgNode).getDirectory();
   else 
     assert (0 && "Invalid DIScope!");
-  return NULL;
+  return StringRef();
 }
 
 //===----------------------------------------------------------------------===//
@@ -481,7 +478,8 @@ void DICompileUnit::dump() const {
 void DIType::dump() const {
   if (isNull()) return;
 
-  if (const char *Res = getName())
+  StringRef Res = getName();
+  if (!Res.empty())
     errs() << " [" << Res << "] ";
 
   unsigned Tag = getTag();
@@ -538,7 +536,8 @@ void DICompositeType::dump() const {
 
 /// dump - Print global.
 void DIGlobal::dump() const {
-  if (const char *Res = getName())
+  StringRef Res = getName();
+  if (!Res.empty())
     errs() << " [" << Res << "] ";
 
   unsigned Tag = getTag();
@@ -562,7 +561,8 @@ void DIGlobal::dump() const {
 
 /// dump - Print subprogram.
 void DISubprogram::dump() const {
-  if (const char *Res = getName())
+  StringRef Res = getName();
+  if (!Res.empty())
     errs() << " [" << Res << "] ";
 
   unsigned Tag = getTag();
@@ -590,7 +590,8 @@ void DIGlobalVariable::dump() const {
 
 /// dump - Print variable.
 void DIVariable::dump() const {
-  if (const char *Res = getName())
+  StringRef Res = getName();
+  if (!Res.empty())
     errs() << " [" << Res << "] ";
 
   getCompileUnit().dump();
@@ -651,12 +652,12 @@ DISubrange DIFactory::GetOrCreateSubrange(int64_t Lo, int64_t Hi) {
 /// CreateCompileUnit - Create a new descriptor for the specified compile
 /// unit.  Note that this does not unique compile units within the module.
 DICompileUnit DIFactory::CreateCompileUnit(unsigned LangID,
-                                           const char * Filename,
-                                           const char * Directory,
-                                           const char * Producer,
+                                           StringRef Filename,
+                                           StringRef Directory,
+                                           StringRef Producer,
                                            bool isMain,
                                            bool isOptimized,
-                                           const char *Flags,
+                                           StringRef Flags,
                                            unsigned RunTimeVer) {
   Value *Elts[] = {
     GetTagConstant(dwarf::DW_TAG_compile_unit),
@@ -675,7 +676,7 @@ DICompileUnit DIFactory::CreateCompileUnit(unsigned LangID,
 }
 
 /// CreateEnumerator - Create a single enumerator value.
-DIEnumerator DIFactory::CreateEnumerator(const char * Name, uint64_t Val){
+DIEnumerator DIFactory::CreateEnumerator(StringRef Name, uint64_t Val){
   Value *Elts[] = {
     GetTagConstant(dwarf::DW_TAG_enumerator),
     MDString::get(VMContext, Name),
@@ -687,7 +688,7 @@ DIEnumerator DIFactory::CreateEnumerator(const char * Name, uint64_t Val){
 
 /// CreateBasicType - Create a basic type like int, float, etc.
 DIBasicType DIFactory::CreateBasicType(DIDescriptor Context,
-                                       const char * Name,
+                                       StringRef Name,
                                        DICompileUnit CompileUnit,
                                        unsigned LineNumber,
                                        uint64_t SizeInBits,
@@ -712,7 +713,7 @@ DIBasicType DIFactory::CreateBasicType(DIDescriptor Context,
 
 /// CreateBasicType - Create a basic type like int, float, etc.
 DIBasicType DIFactory::CreateBasicTypeEx(DIDescriptor Context,
-                                         const char * Name,
+                                         StringRef Name,
                                          DICompileUnit CompileUnit,
                                          unsigned LineNumber,
                                          Constant *SizeInBits,
@@ -739,7 +740,7 @@ DIBasicType DIFactory::CreateBasicTypeEx(DIDescriptor Context,
 /// pointer, typedef, etc.
 DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
                                            DIDescriptor Context,
-                                           const char * Name,
+                                           StringRef Name,
                                            DICompileUnit CompileUnit,
                                            unsigned LineNumber,
                                            uint64_t SizeInBits,
@@ -767,7 +768,7 @@ DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
 /// pointer, typedef, etc.
 DIDerivedType DIFactory::CreateDerivedTypeEx(unsigned Tag,
                                              DIDescriptor Context,
-                                             const char * Name,
+                                             StringRef Name,
                                              DICompileUnit CompileUnit,
                                              unsigned LineNumber,
                                              Constant *SizeInBits,
@@ -794,7 +795,7 @@ DIDerivedType DIFactory::CreateDerivedTypeEx(unsigned Tag,
 /// CreateCompositeType - Create a composite type like array, struct, etc.
 DICompositeType DIFactory::CreateCompositeType(unsigned Tag,
                                                DIDescriptor Context,
-                                               const char * Name,
+                                               StringRef Name,
                                                DICompileUnit CompileUnit,
                                                unsigned LineNumber,
                                                uint64_t SizeInBits,
@@ -826,7 +827,7 @@ DICompositeType DIFactory::CreateCompositeType(unsigned Tag,
 /// CreateCompositeType - Create a composite type like array, struct, etc.
 DICompositeType DIFactory::CreateCompositeTypeEx(unsigned Tag,
                                                  DIDescriptor Context,
-                                                 const char * Name,
+                                                 StringRef Name,
                                                  DICompileUnit CompileUnit,
                                                  unsigned LineNumber,
                                                  Constant *SizeInBits,
@@ -859,9 +860,9 @@ DICompositeType DIFactory::CreateCompositeTypeEx(unsigned Tag,
 /// See comments in DISubprogram for descriptions of these fields.  This
 /// method does not unique the generated descriptors.
 DISubprogram DIFactory::CreateSubprogram(DIDescriptor Context,
-                                         const char * Name,
-                                         const char * DisplayName,
-                                         const char * LinkageName,
+                                         StringRef Name,
+                                         StringRef DisplayName,
+                                         StringRef LinkageName,
                                          DICompileUnit CompileUnit,
                                          unsigned LineNo, DIType Type,
                                          bool isLocalToUnit,
@@ -885,9 +886,9 @@ DISubprogram DIFactory::CreateSubprogram(DIDescriptor Context,
 
 /// CreateGlobalVariable - Create a new descriptor for the specified global.
 DIGlobalVariable
-DIFactory::CreateGlobalVariable(DIDescriptor Context, const char * Name,
-                                const char * DisplayName,
-                                const char * LinkageName,
+DIFactory::CreateGlobalVariable(DIDescriptor Context, StringRef Name,
+                                StringRef DisplayName,
+                                StringRef LinkageName,
                                 DICompileUnit CompileUnit,
                                 unsigned LineNo, DIType Type,bool isLocalToUnit,
                                 bool isDefinition, llvm::GlobalVariable *Val) {
@@ -919,7 +920,7 @@ DIFactory::CreateGlobalVariable(DIDescriptor Context, const char * Name,
 
 /// CreateVariable - Create a new descriptor for the specified variable.
 DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
-                                     const char * Name,
+                                     StringRef Name,
                                      DICompileUnit CompileUnit, unsigned LineNo,
                                      DIType Type) {
   Value *Elts[] = {
@@ -1274,7 +1275,8 @@ bool getLocationInfo(const Value *V, std::string &DisplayName,
       if (!DIGV) return false;
       DIGlobalVariable Var(cast<MDNode>(DIGV));
 
-      if (const char *D = Var.getDisplayName())
+      StringRef D = Var.getDisplayName();
+      if (!D.empty())
         DisplayName = D;
       LineNo = Var.getLineNumber();
       Unit = Var.getCompileUnit();
@@ -1284,18 +1286,22 @@ bool getLocationInfo(const Value *V, std::string &DisplayName,
       if (!DDI) return false;
       DIVariable Var(cast<MDNode>(DDI->getVariable()));
 
-      if (const char *D = Var.getName())
+      StringRef D = Var.getName();
+      if (!D.empty())
         DisplayName = D;
       LineNo = Var.getLineNumber();
       Unit = Var.getCompileUnit();
       TypeD = Var.getType();
     }
 
-    if (const char *T = TypeD.getName())
+    StringRef T = TypeD.getName();
+    if (!T.empty())
       Type = T;
-    if (const char *F = Unit.getFilename())
+    StringRef F = Unit.getFilename();
+    if (!F.empty())
       File = F;
-    if (const char *D = Unit.getDirectory())
+    StringRef D = Unit.getDirectory();
+    if (!D.empty())
       Dir = D;
     return true;
   }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index f8873a4d941..ab9d96f25f0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -494,7 +494,7 @@ DIType DwarfDebug::getBlockByrefType(DIType Ty, std::string Name) {
   for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
     DIDescriptor Element = Elements.getElement(i);
     DIDerivedType DT = DIDerivedType(Element.getNode());
-    if (strcmp(Name.c_str(), DT.getName()) == 0)
+    if (Name == DT.getName())
       return (DT.getTypeDerivedFrom());
   }
 
@@ -620,7 +620,7 @@ void DwarfDebug::addBlockByrefAddress(DbgVariable *&DV, DIE *Die,
   unsigned Tag = Ty.getTag();
   bool isPointer = false;
 
-  const char *varName = VD.getName();
+  StringRef varName = VD.getName();
 
   if (Tag == dwarf::DW_TAG_pointer_type) {
     DIDerivedType DTy = DIDerivedType(Ty.getNode());
@@ -640,10 +640,10 @@ void DwarfDebug::addBlockByrefAddress(DbgVariable *&DV, DIE *Die,
   for (unsigned i = 0, N = Fields.getNumElements(); i < N; ++i) {
     DIDescriptor Element = Fields.getElement(i);
     DIDerivedType DT = DIDerivedType(Element.getNode());
-    const char *fieldName = DT.getName();
-    if (strcmp(fieldName, "__forwarding") == 0)
+    StringRef fieldName = DT.getName();
+    if (fieldName == "__forwarding")
       forwardingField = Element;
-    else if (strcmp(fieldName, varName) == 0)
+    else if (fieldName == varName)
       varField = Element;
   }
 
@@ -785,13 +785,13 @@ void DwarfDebug::addType(CompileUnit *DW_Unit, DIE *Entity, DIType Ty) {
 void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
                                   DIBasicType BTy) {
   // Get core information.
-  const char *Name = BTy.getName();
+  StringRef Name = BTy.getName();
   Buffer.setTag(dwarf::DW_TAG_base_type);
   addUInt(&Buffer, dwarf::DW_AT_encoding,  dwarf::DW_FORM_data1,
           BTy.getEncoding());
 
   // Add name if not anonymous or intermediate type.
-  if (Name)
+  if (!Name.empty())
     addString(&Buffer, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
   uint64_t Size = BTy.getSizeInBits() >> 3;
   addUInt(&Buffer, dwarf::DW_AT_byte_size, 0, Size);
@@ -801,7 +801,7 @@ void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
 void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
                                   DIDerivedType DTy) {
   // Get core information.
-  const char *Name = DTy.getName();
+  StringRef Name = DTy.getName();
   uint64_t Size = DTy.getSizeInBits() >> 3;
   unsigned Tag = DTy.getTag();
 
@@ -815,7 +815,7 @@ void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
   addType(DW_Unit, &Buffer, FromTy);
 
   // Add name if not anonymous or intermediate type.
-  if (Name && Tag != dwarf::DW_TAG_pointer_type)
+  if (!Name.empty() && Tag != dwarf::DW_TAG_pointer_type)
     addString(&Buffer, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
   // Add size if non-zero (derived types might be zero-sized.)
@@ -831,7 +831,7 @@ void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
 void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
                                   DICompositeType CTy) {
   // Get core information.
-  const char *Name = CTy.getName();
+  StringRef Name = CTy.getName();
 
   uint64_t Size = CTy.getSizeInBits() >> 3;
   unsigned Tag = CTy.getTag();
@@ -913,7 +913,7 @@ void DwarfDebug::constructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
   }
 
   // Add name if not anonymous or intermediate type.
-  if (Name)
+  if (!Name.empty())
     addString(&Buffer, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
   if (Tag == dwarf::DW_TAG_enumeration_type ||
@@ -984,7 +984,7 @@ void DwarfDebug::constructArrayTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
 /// constructEnumTypeDIE - Construct enum type DIE from DIEnumerator.
 DIE *DwarfDebug::constructEnumTypeDIE(CompileUnit *DW_Unit, DIEnumerator *ETy) {
   DIE *Enumerator = new DIE(dwarf::DW_TAG_enumerator);
-  const char *Name = ETy->getName();
+  StringRef Name = ETy->getName();
   addString(Enumerator, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
   int64_t Value = ETy->getEnumValue();
   addSInt(Enumerator, dwarf::DW_AT_const_value, dwarf::DW_FORM_sdata, Value);
@@ -997,20 +997,20 @@ DIE *DwarfDebug::createGlobalVariableDIE(CompileUnit *DW_Unit,
   // If the global variable was optmized out then no need to create debug info
   // entry.
   if (!GV.getGlobal()) return NULL;
-  if (!GV.getDisplayName()) return NULL;
+  if (GV.getDisplayName().empty()) return NULL;
 
   DIE *GVDie = new DIE(dwarf::DW_TAG_variable);
   addString(GVDie, dwarf::DW_AT_name, dwarf::DW_FORM_string,
             GV.getDisplayName());
 
-  const char *LinkageName = GV.getLinkageName();
-  if (LinkageName) {
+  StringRef LinkageName = GV.getLinkageName();
+  if (!LinkageName.empty()) {
     // Skip special LLVM prefix that is used to inform the asm printer to not
     // emit usual symbol prefix before the symbol name. This happens for
     // Objective-C symbol names and symbol whose name is replaced using GCC's
     // __asm__ attribute.
     if (LinkageName[0] == 1)
-      LinkageName = &LinkageName[1];
+      LinkageName = LinkageName.data() + 1;
     addString(GVDie, dwarf::DW_AT_MIPS_linkage_name, dwarf::DW_FORM_string,
               LinkageName);
   }
@@ -1032,9 +1032,10 @@ DIE *DwarfDebug::createGlobalVariableDIE(CompileUnit *DW_Unit,
 /// createMemberDIE - Create new member DIE.
 DIE *DwarfDebug::createMemberDIE(CompileUnit *DW_Unit, const DIDerivedType &DT){
   DIE *MemberDie = new DIE(DT.getTag());
-  if (const char *Name = DT.getName())
+  StringRef Name = DT.getName();
+  if (!Name.empty())
     addString(MemberDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
-
+  
   addType(DW_Unit, MemberDie, DT.getTypeDerivedFrom());
 
   addSourceLine(MemberDie, &DT);
@@ -1087,18 +1088,16 @@ DIE *DwarfDebug::createSubprogramDIE(CompileUnit *DW_Unit,
                                      bool IsConstructor,
                                      bool IsInlined) {
   DIE *SPDie = new DIE(dwarf::DW_TAG_subprogram);
+  addString(SPDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, SP.getName());
 
-  const char * Name = SP.getName();
-  addString(SPDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
-
-  const char *LinkageName = SP.getLinkageName();
-  if (LinkageName) {
+  StringRef LinkageName = SP.getLinkageName();
+  if (!LinkageName.empty()) {
     // Skip special LLVM prefix that is used to inform the asm printer to not
     // emit usual symbol prefix before the symbol name. This happens for
     // Objective-C symbol names and symbol whose name is replaced using GCC's
     // __asm__ attribute.
     if (LinkageName[0] == 1)
-      LinkageName = &LinkageName[1];
+      LinkageName = LinkageName.data() + 1;
     addString(SPDie, dwarf::DW_AT_MIPS_linkage_name, dwarf::DW_FORM_string,
               LinkageName);
   }
@@ -1155,8 +1154,8 @@ CompileUnit &DwarfDebug::findCompileUnit(DICompileUnit Unit) const {
 DIE *DwarfDebug::createDbgScopeVariable(DbgVariable *DV, CompileUnit *Unit) {
   // Get the descriptor.
   const DIVariable &VD = DV->getVariable();
-  const char *Name = VD.getName();
-  if (!Name)
+  StringRef Name = VD.getName();
+  if (Name.empty())
     return NULL;
 
   // Translate tag to proper Dwarf tag.  The result variable is dropped for
@@ -1406,8 +1405,8 @@ DIE *DwarfDebug::constructVariableDIE(DbgVariable *DV,
                                       DbgScope *Scope, CompileUnit *Unit) {
   // Get the descriptor.
   const DIVariable &VD = DV->getVariable();
-  const char *Name = VD.getName();
-  if (!Name)
+  StringRef Name = VD.getName();
+  if (Name.empty())
     return NULL;
 
   // Translate tag to proper Dwarf tag.  The result variable is dropped for
@@ -1491,7 +1490,7 @@ void DwarfDebug::addPubTypes(DISubprogram SP) {
     if (ATy.isNull())
       continue;
     DICompositeType CATy = getDICompositeType(ATy);
-    if (!CATy.isNull() && CATy.getName()) {
+    if (!CATy.isNull() && !CATy.getName().empty()) {
       if (DIEEntry *Entry = ModuleCU->getDIEEntry(CATy.getNode()))
         ModuleCU->addGlobalType(CATy.getName(), Entry->getEntry());
     }
@@ -1547,8 +1546,7 @@ DIE *DwarfDebug::constructScopeDIE(DbgScope *Scope) {
 /// source file names. If none currently exists, create a new id and insert it
 /// in the SourceIds map. This can update DirectoryNames and SourceFileNames
 /// maps as well.
-unsigned DwarfDebug::GetOrCreateSourceID(const char *DirName,
-                                         const char *FileName) {
+unsigned DwarfDebug::GetOrCreateSourceID(StringRef DirName, StringRef FileName) {
   unsigned DId;
   StringMap<unsigned>::iterator DI = DirectoryIdMap.find(DirName);
   if (DI != DirectoryIdMap.end()) {
@@ -1583,8 +1581,8 @@ unsigned DwarfDebug::GetOrCreateSourceID(const char *DirName,
 
 void DwarfDebug::constructCompileUnit(MDNode *N) {
   DICompileUnit DIUnit(N);
-  const char *FN = DIUnit.getFilename();
-  const char *Dir = DIUnit.getDirectory();
+  StringRef FN = DIUnit.getFilename();
+  StringRef Dir = DIUnit.getDirectory();
   unsigned ID = GetOrCreateSourceID(Dir, FN);
 
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
@@ -1597,12 +1595,13 @@ void DwarfDebug::constructCompileUnit(MDNode *N) {
           DIUnit.getLanguage());
   addString(Die, dwarf::DW_AT_name, dwarf::DW_FORM_string, FN);
 
-  if (Dir)
+  if (!Dir.empty())
     addString(Die, dwarf::DW_AT_comp_dir, dwarf::DW_FORM_string, Dir);
   if (DIUnit.isOptimized())
     addUInt(Die, dwarf::DW_AT_APPLE_optimized, dwarf::DW_FORM_flag, 1);
 
-  if (const char *Flags = DIUnit.getFlags())
+  StringRef Flags = DIUnit.getFlags();
+  if (!Flags.empty())
     addString(Die, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string, Flags);
 
   unsigned RVer = DIUnit.getRunTimeVersion();
@@ -1644,7 +1643,7 @@ void DwarfDebug::constructGlobalVariableDIE(MDNode *N) {
   ModuleCU->addGlobal(DI_GV.getName(), VariableDie);
 
   DIType GTy = DI_GV.getType();
-  if (GTy.isCompositeType() && GTy.getName()) {
+  if (GTy.isCompositeType() && !GTy.getName().empty()) {
     DIEEntry *Entry = ModuleCU->getDIEEntry(GTy.getNode());
     assert (Entry && "Missing global type!");
     ModuleCU->addGlobalType(GTy.getName(), Entry->getEntry());
@@ -2119,8 +2118,8 @@ unsigned DwarfDebug::recordSourceLine(unsigned Line, unsigned Col,
   if (TimePassesIsEnabled)
     DebugTimer->startTimer();
 
-  const char *Dir = NULL;
-  const char *Fn = NULL;
+  StringRef Dir;
+  StringRef Fn;
 
   DIDescriptor Scope(S);
   if (Scope.isCompileUnit()) {
@@ -2889,10 +2888,10 @@ void DwarfDebug::emitDebugInlineInfo() {
       = InlineInfo.find(Node);
     SmallVector<InlineInfoLabels, 4> &Labels = II->second;
     DISubprogram SP(Node);
-    const char *LName = SP.getLinkageName();
-    const char *Name = SP.getName();
+    StringRef LName = SP.getLinkageName();
+    StringRef Name = SP.getName();
 
-    if (!LName)
+    if (LName.empty())
       Asm->EmitString(Name);
     else {
       // Skip special LLVM prefix that is used to inform the asm printer to not
@@ -2900,7 +2899,7 @@ void DwarfDebug::emitDebugInlineInfo() {
       // Objective-C symbol names and symbol whose name is replaced using GCC's
       // __asm__ attribute.
       if (LName[0] == 1)
-        LName = &LName[1];
+        LName = LName.data() + 1;
 //      Asm->EmitString(LName);
       EmitSectionOffset("string", "section_str",
                         StringPool.idFor(LName), false, true);
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 19583b84c5f..679d9b9d1a0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -486,8 +486,7 @@ class DwarfDebug : public Dwarf {
   /// source file names. If none currently exists, create a new id and insert it
   /// in the SourceIds map. This can update DirectoryNames and SourceFileNames maps
   /// as well.
-  unsigned GetOrCreateSourceID(const char *DirName,
-                               const char *FileName);
+  unsigned GetOrCreateSourceID(StringRef DirName, StringRef FileName);
 
   void constructCompileUnit(MDNode *N);
 
diff --git a/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp b/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp
index 0ed44d21fc4..74dcf60ca7c 100644
--- a/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp
+++ b/llvm/lib/Target/PIC16/PIC16DebugInfo.cpp
@@ -306,10 +306,10 @@ void PIC16DbgInfo::EmitCompositeTypeElements (DICompositeType CTy,
     int ElementAux[PIC16Dbg::AuxSize] = { 0 };
     std::string TagName = "";
     DIDerivedType DITy(Element.getNode());
-    const char *ElementName = DITy.getName();
+    StringRef ElementName = DITy.getName();
     unsigned short ElementSize = DITy.getSizeInBits()/8;
     // Get mangleddd name for this structure/union  element.
-    std::string MangMemName = ElementName + SuffixNo;
+    std::string MangMemName = ElementName.data() + SuffixNo;
     PopulateDebugInfo(DITy, TypeNo, HasAux, ElementAux, TagName);
     short Class = 0;
     if( CTy.getTag() == dwarf::DW_TAG_union_type)
@@ -337,12 +337,12 @@ void PIC16DbgInfo::EmitCompositeTypeDecls(Module &M) {
       continue;
     if (CTy.getTag() == dwarf::DW_TAG_union_type ||
         CTy.getTag() == dwarf::DW_TAG_structure_type ) {
-      const char *Name = CTy.getName();
+      StringRef Name = CTy.getName();
       // Get the number after llvm.dbg.composite and make UniqueSuffix from 
       // it.
       std::string DIVar = CTy.getNode()->getNameStr();
       std::string UniqueSuffix = "." + DIVar.substr(18);
-      std::string MangledCTyName = Name + UniqueSuffix;
+      std::string MangledCTyName = Name.data() + UniqueSuffix;
       unsigned short size = CTy.getSizeInBits()/8;
       int Aux[PIC16Dbg::AuxSize] = {0};
       // 7th and 8th byte represent size of structure/union.