Remove std::string uses from DebugInfo interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83083 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 141 insertions, 222 deletions

diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index 35f6787..8082279 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -53,7 +53,7 @@ namespace llvm {
     /// not, the debug info is corrupt and we ignore it.
     DIDescriptor(MDNode *N, unsigned RequiredTag);
 
-    const std::string &getStringField(unsigned Elt, std::string &Result) const;
+    const char *getStringField(unsigned Elt) const;
     unsigned getUnsignedField(unsigned Elt) const {
       return (unsigned)getUInt64Field(Elt);
     }
@@ -131,13 +131,8 @@ namespace llvm {
     }
     virtual ~DIScope() {}
 
-    virtual const std::string &getFilename(std::string &F) const {
-      return F;
-    }
-
-    virtual const std::string &getDirectory(std::string &D) const {
-      return D;
-    }
+    virtual const char *getFilename() const { return NULL; }
+    virtual const char *getDirectory() const { return NULL; }
   };
 
   /// DICompileUnit - A wrapper for a compile unit.
@@ -149,15 +144,9 @@ namespace llvm {
     }
 
     unsigned getLanguage() const     { return getUnsignedField(2); }
-    const std::string &getFilename(std::string &F) const {
-      return getStringField(3, F);
-    }
-    const std::string &getDirectory(std::string &F) const {
-      return getStringField(4, F);
-    }
-    const std::string &getProducer(std::string &F) const {
-      return getStringField(5, F);
-    }
+    const char *getFilename() const  { return getStringField(3);   }
+    const char *getDirectory() const { return getStringField(4);   }
+    const char *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
@@ -170,9 +159,7 @@ namespace llvm {
 
     bool isMain() const                { return getUnsignedField(6); }
     bool isOptimized() const           { return getUnsignedField(7); }
-    const std::string &getFlags(std::string &F) const {
-      return getStringField(8, F);
-    }
+    const char *getFlags() const       { return getStringField(8);   }
     unsigned getRunTimeVersion() const { return getUnsignedField(9); }
 
     /// Verify - Verify that a compile unit is well formed.
@@ -190,10 +177,8 @@ namespace llvm {
     explicit DIEnumerator(MDNode *N = 0)
       : DIDescriptor(N, dwarf::DW_TAG_enumerator) {}
 
-    const std::string &getName(std::string &F) const {
-      return getStringField(1, F);
-    }
-    uint64_t getEnumValue() const { return getUInt64Field(2); }
+    const char *getName() const        { return getStringField(1); }
+    uint64_t getEnumValue() const      { return getUInt64Field(2); }
   };
 
   /// DIType - This is a wrapper for a type.
@@ -226,9 +211,7 @@ namespace llvm {
     virtual ~DIType() {}
 
     DIDescriptor getContext() const     { return getDescriptorField(1); }
-    const std::string &getName(std::string &F) const {
-      return getStringField(2, F);
-    }
+    const char *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); }
@@ -328,15 +311,9 @@ namespace llvm {
     virtual ~DIGlobal() {}
 
     DIDescriptor getContext() const     { return getDescriptorField(2); }
-    const std::string &getName(std::string &F) const {
-      return getStringField(3, F);
-    }
-    const std::string &getDisplayName(std::string &F) const {
-      return getStringField(4, F);
-    }
-    const std::string &getLinkageName(std::string &F) const {
-      return getStringField(5, F);
-    }
+    const char *getName() const         { return getStringField(3); }
+    const char *getDisplayName() const  { return getStringField(4); }
+    const char *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); }
@@ -359,43 +336,32 @@ namespace llvm {
     }
 
     DIDescriptor getContext() const     { return getDescriptorField(2); }
-    const std::string &getName(std::string &F) const {
-      return getStringField(3, F);
-    }
-    const std::string &getDisplayName(std::string &F) const {
-      return getStringField(4, F);
-    }
-    const std::string &getLinkageName(std::string &F) const {
-      return getStringField(5, F);
-    }
+    const char *getName() const         { return getStringField(3); }
+    const char *getDisplayName() const  { return getStringField(4); }
+    const char *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 std::string &getReturnTypeName(std::string &F) const {
+    const char *getReturnTypeName() const {
       DICompositeType DCT(getFieldAs<DICompositeType>(8));
       if (!DCT.isNull()) {
         DIArray A = DCT.getTypeArray();
         DIType T(A.getElement(0).getNode());
-        return T.getName(F);
+        return T.getName();
       }
       DIType T(getFieldAs<DIType>(8));
-      return T.getName(F);
+      return T.getName();
     }
 
     /// isLocalToUnit - Return true if this subprogram is local to the current
     /// compile unit, like 'static' in C.
-    unsigned isLocalToUnit() const      { return getUnsignedField(9); }
-    unsigned isDefinition() const       { return getUnsignedField(10); }
-
-    const std::string &getFilename(std::string &F) const {
-      return getCompileUnit().getFilename(F);
-    }
-    const std::string &getDirectory(std::string &F) const {
-      return getCompileUnit().getDirectory(F);
-    }
+    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();}
 
     /// Verify - Verify that a subprogram descriptor is well formed.
     bool Verify() const;
@@ -434,9 +400,7 @@ namespace llvm {
     }
 
     DIDescriptor getContext() const { return getDescriptorField(1); }
-    const std::string &getName(std::string &F) const {
-      return getStringField(2, F);
-    }
+    const char *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); }
@@ -462,14 +426,8 @@ namespace llvm {
       if (DbgNode && !isLexicalBlock())
         DbgNode = 0;
     }
-    DIScope getContext() const { return getFieldAs<DIScope>(1); }
-
-    const std::string &getFilename(std::string &F) const {
-      return getContext().getFilename(F);
-    }
-    const std::string &getDirectory(std::string &D) const {
-      return getContext().getDirectory(D);
-    }
+    DIScope getContext() const       { return getFieldAs<DIScope>(1); }
+    const char *getFilename() const  { return getContext().getFilename(); }
   };
 
   /// DILocation - This object holds location information. This object
@@ -480,14 +438,10 @@ namespace llvm {
 
     unsigned getLineNumber() const     { return getUnsignedField(0); }
     unsigned getColumnNumber() const   { return getUnsignedField(1); }
-    DIScope  getScope() const          { return getFieldAs<DIScope>(3); }
-    DILocation getOrigLocation() const { return getFieldAs<DILocation>(4); }
-    std::string getFilename(std::string &F) const  {
-      return getScope().getFilename(F);
-    }
-    std::string getDirectory(std::string &D) const {
-      return getScope().getDirectory(D);
-    }
+    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(); }
   };
 
   /// DIFactory - This object assists with the construction of the various
@@ -522,19 +476,19 @@ namespace llvm {
     /// CreateCompileUnit - Create a new descriptor for the specified compile
     /// unit.
     DICompileUnit CreateCompileUnit(unsigned LangID,
-                                    const std::string &Filename,
-                                    const std::string &Directory,
-                                    const std::string &Producer,
+                                    StringRef Filenae,
+                                    StringRef Directory,
+                                    StringRef Producer,
                                     bool isMain = false,
                                     bool isOptimized = false,
                                     const char *Flags = "",
                                     unsigned RunTimeVer = 0);
 
     /// CreateEnumerator - Create a single enumerator value.
-    DIEnumerator CreateEnumerator(const std::string &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 std::string &Name,
+    DIBasicType CreateBasicType(DIDescriptor Context, StringRef Name,
                                 DICompileUnit CompileUnit, unsigned LineNumber,
                                 uint64_t SizeInBits, uint64_t AlignInBits,
                                 uint64_t OffsetInBits, unsigned Flags,
@@ -543,7 +497,7 @@ namespace llvm {
     /// CreateDerivedType - Create a derived type like const qualified type,
     /// pointer, typedef, etc.
     DIDerivedType CreateDerivedType(unsigned Tag, DIDescriptor Context,
-                                    const std::string &Name,
+                                    StringRef Name,
                                     DICompileUnit CompileUnit,
                                     unsigned LineNumber,
                                     uint64_t SizeInBits, uint64_t AlignInBits,
@@ -552,7 +506,7 @@ namespace llvm {
 
     /// CreateCompositeType - Create a composite type like array, struct, etc.
     DICompositeType CreateCompositeType(unsigned Tag, DIDescriptor Context,
-                                        const std::string &Name,
+                                        StringRef Name,
                                         DICompileUnit CompileUnit,
                                         unsigned LineNumber,
                                         uint64_t SizeInBits,
@@ -564,25 +518,25 @@ 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 std::string &Name,
-                                  const std::string &DisplayName,
-                                  const std::string &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 std::string &Name,
-                         const std::string &DisplayName,
-                         const std::string &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 std::string &Name,
+                              StringRef Name,
                               DICompileUnit CompileUnit, unsigned LineNo,
                               DIType Type);
 
@@ -633,9 +587,9 @@ namespace llvm {
   /// Find the debug info descriptor corresponding to this global variable.
   Value *findDbgGlobalDeclare(GlobalVariable *V);
 
-  bool getLocationInfo(const Value *V, std::string &DisplayName,
-                       std::string &Type, unsigned &LineNo, std::string &File,
-                       std::string &Dir);
+bool getLocationInfo(const Value *V, std::string &DisplayName,
+                     std::string &Type, unsigned &LineNo, std::string &File,
+                     std::string &Dir);
 
   /// isValidDebugInfoIntrinsic - Return true if SPI is a valid debug
   /// info intrinsic.
diff --git a/lib/Analysis/DbgInfoPrinter.cpp b/lib/Analysis/DbgInfoPrinter.cpp
index 8063476..2bbe2e0 100644
--- a/lib/Analysis/DbgInfoPrinter.cpp
+++ b/lib/Analysis/DbgInfoPrinter.cpp
@@ -91,9 +91,8 @@ void PrintDbgInfo::printStopPoint(const DbgStopPointInst *DSI) {
 
 void PrintDbgInfo::printFuncStart(const DbgFuncStartInst *FS) {
   DISubprogram Subprogram(FS->getSubprogram());
-  std::string Res1, Res2;
-  Out << "; fully qualified function name: " << Subprogram.getDisplayName(Res1)
-      << " return type: " << Subprogram.getReturnTypeName(Res2)
+  Out << "; fully qualified function name: " << Subprogram.getDisplayName()
+      << " return type: " << Subprogram.getReturnTypeName()
       << " at line " << Subprogram.getLineNumber()
       << "\n\n";
 }
diff --git a/lib/Analysis/DebugInfo.cpp b/lib/Analysis/DebugInfo.cpp
index 531f609..58bee90 100644
--- a/lib/Analysis/DebugInfo.cpp
+++ b/lib/Analysis/DebugInfo.cpp
@@ -78,19 +78,16 @@ DIDescriptor::DIDescriptor(MDNode *N, unsigned RequiredTag) {
   }
 }
 
-const std::string &
-DIDescriptor::getStringField(unsigned Elt, std::string &Result) const {
-  Result.clear();
+const char *
+DIDescriptor::getStringField(unsigned Elt) const {
   if (DbgNode == 0)
-    return Result;
+    return NULL;
 
   if (Elt < DbgNode->getNumElements())
-    if (MDString *MDS = dyn_cast_or_null<MDString>(DbgNode->getElement(Elt))) {
-      Result.assign(MDS->begin(), MDS->begin() + MDS->length());
-      return Result;
-    }
+    if (MDString *MDS = dyn_cast_or_null<MDString>(DbgNode->getElement(Elt)))
+      return MDS->getString().data();
 
-  return Result;
+  return NULL;
 }
 
 uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
@@ -284,8 +281,8 @@ void DIDerivedType::replaceAllUsesWith(DIDescriptor &D) {
 bool DICompileUnit::Verify() const {
   if (isNull())
     return false;
-  std::string Res;
-  if (getFilename(Res).empty())
+  const char *N = getFilename();
+  if (!N)
     return false;
   // It is possible that directory and produce string is empty.
   return true;
@@ -387,11 +384,10 @@ uint64_t DIDerivedType::getOriginalTypeSize() const {
 /// information for the function F.
 bool DISubprogram::describes(const Function *F) {
   assert (F && "Invalid function");
-  std::string Name;
-  getLinkageName(Name);
-  if (Name.empty())
-    getName(Name);
-  if (F->getName() == Name)
+  const char *Name = getLinkageName();
+  if (!Name)
+    Name = getName();
+  if (strcmp(F->getName().data(), Name) == 0)
     return true;
   return false;
 }
@@ -412,16 +408,14 @@ void DICompileUnit::dump() const {
   if (getLanguage())
     errs() << " [" << dwarf::LanguageString(getLanguage()) << "] ";
 
-  std::string Res1, Res2;
-  errs() << " [" << getDirectory(Res1) << "/" << getFilename(Res2) << " ]";
+  errs() << " [" << getDirectory() << "/" << getFilename() << " ]";
 }
 
 /// dump - Print type.
 void DIType::dump() const {
   if (isNull()) return;
 
-  std::string Res;
-  if (!getName(Res).empty())
+  if (const char *Res = getName())
     errs() << " [" << Res << "] ";
 
   unsigned Tag = getTag();
@@ -478,8 +472,7 @@ void DICompositeType::dump() const {
 
 /// dump - Print global.
 void DIGlobal::dump() const {
-  std::string Res;
-  if (!getName(Res).empty())
+  if (const char *Res = getName())
     errs() << " [" << Res << "] ";
 
   unsigned Tag = getTag();
@@ -503,8 +496,7 @@ void DIGlobal::dump() const {
 
 /// dump - Print subprogram.
 void DISubprogram::dump() const {
-  std::string Res;
-  if (!getName(Res).empty())
+  if (const char *Res = getName())
     errs() << " [" << Res << "] ";
 
   unsigned Tag = getTag();
@@ -532,8 +524,7 @@ void DIGlobalVariable::dump() const {
 
 /// dump - Print variable.
 void DIVariable::dump() const {
-  std::string Res;
-  if (!getName(Res).empty())
+  if (const char *Res = getName())
     errs() << " [" << Res << "] ";
 
   getCompileUnit().dump();
@@ -594,9 +585,9 @@ 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 std::string &Filename,
-                                           const std::string &Directory,
-                                           const std::string &Producer,
+                                           StringRef Filename,
+                                           StringRef Directory,
+                                           StringRef Producer,
                                            bool isMain,
                                            bool isOptimized,
                                            const char *Flags,
@@ -618,7 +609,7 @@ DICompileUnit DIFactory::CreateCompileUnit(unsigned LangID,
 }
 
 /// CreateEnumerator - Create a single enumerator value.
-DIEnumerator DIFactory::CreateEnumerator(const std::string &Name, uint64_t Val){
+DIEnumerator DIFactory::CreateEnumerator(StringRef Name, uint64_t Val){
   Value *Elts[] = {
     GetTagConstant(dwarf::DW_TAG_enumerator),
     MDString::get(VMContext, Name),
@@ -630,7 +621,7 @@ DIEnumerator DIFactory::CreateEnumerator(const std::string &Name, uint64_t Val){
 
 /// CreateBasicType - Create a basic type like int, float, etc.
 DIBasicType DIFactory::CreateBasicType(DIDescriptor Context,
-                                      const std::string &Name,
+                                       StringRef Name,
                                        DICompileUnit CompileUnit,
                                        unsigned LineNumber,
                                        uint64_t SizeInBits,
@@ -656,7 +647,7 @@ DIBasicType DIFactory::CreateBasicType(DIDescriptor Context,
 /// pointer, typedef, etc.
 DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
                                            DIDescriptor Context,
-                                           const std::string &Name,
+                                           StringRef Name,
                                            DICompileUnit CompileUnit,
                                            unsigned LineNumber,
                                            uint64_t SizeInBits,
@@ -682,7 +673,7 @@ DIDerivedType DIFactory::CreateDerivedType(unsigned Tag,
 /// CreateCompositeType - Create a composite type like array, struct, etc.
 DICompositeType DIFactory::CreateCompositeType(unsigned Tag,
                                                DIDescriptor Context,
-                                               const std::string &Name,
+                                               StringRef Name,
                                                DICompileUnit CompileUnit,
                                                unsigned LineNumber,
                                                uint64_t SizeInBits,
@@ -715,9 +706,9 @@ DICompositeType DIFactory::CreateCompositeType(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 std::string &Name,
-                                         const std::string &DisplayName,
-                                         const std::string &LinkageName,
+                                         StringRef Name,
+                                         StringRef DisplayName,
+                                         StringRef LinkageName,
                                          DICompileUnit CompileUnit,
                                          unsigned LineNo, DIType Type,
                                          bool isLocalToUnit,
@@ -741,9 +732,9 @@ DISubprogram DIFactory::CreateSubprogram(DIDescriptor Context,
 
 /// CreateGlobalVariable - Create a new descriptor for the specified global.
 DIGlobalVariable
-DIFactory::CreateGlobalVariable(DIDescriptor Context, const std::string &Name,
-                                const std::string &DisplayName,
-                                const std::string &LinkageName,
+DIFactory::CreateGlobalVariable(DIDescriptor Context, StringRef Name,
+                                StringRef DisplayName,
+                                StringRef LinkageName,
                                 DICompileUnit CompileUnit,
                                 unsigned LineNo, DIType Type,bool isLocalToUnit,
                                 bool isDefinition, llvm::GlobalVariable *Val) {
@@ -775,7 +766,7 @@ DIFactory::CreateGlobalVariable(DIDescriptor Context, const std::string &Name,
 
 /// CreateVariable - Create a new descriptor for the specified variable.
 DIVariable DIFactory::CreateVariable(unsigned Tag, DIDescriptor Context,
-                                     const std::string &Name,
+                                     StringRef Name,
                                      DICompileUnit CompileUnit, unsigned LineNo,
                                      DIType Type) {
   Value *Elts[] = {
@@ -1127,8 +1118,8 @@ namespace llvm {
     return 0;
   }
 
-  bool getLocationInfo(const Value *V, std::string &DisplayName,
-                       std::string &Type, unsigned &LineNo, std::string &File,
+bool getLocationInfo(const Value *V, std::string &DisplayName,
+                     std::string &Type, unsigned &LineNo, std::string &File,
                        std::string &Dir) {
     DICompileUnit Unit;
     DIType TypeD;
@@ -1138,7 +1129,8 @@ namespace llvm {
       if (!DIGV) return false;
       DIGlobalVariable Var(cast<MDNode>(DIGV));
 
-      Var.getDisplayName(DisplayName);
+      if (const char *D = Var.getDisplayName())
+        DisplayName = D;
       LineNo = Var.getLineNumber();
       Unit = Var.getCompileUnit();
       TypeD = Var.getType();
@@ -1147,15 +1139,19 @@ namespace llvm {
       if (!DDI) return false;
       DIVariable Var(cast<MDNode>(DDI->getVariable()));
 
-      Var.getName(DisplayName);
+      if (const char *D = Var.getName())
+        DisplayName = D;
       LineNo = Var.getLineNumber();
       Unit = Var.getCompileUnit();
       TypeD = Var.getType();
     }
 
-    TypeD.getName(Type);
-    Unit.getFilename(File);
-    Unit.getDirectory(Dir);
+    if (const char *T = TypeD.getName())
+      Type = T;
+    if (const char *F = Unit.getFilename())
+      File = F;
+    if (const char *D = Unit.getDirectory())
+      Dir = D;
     return true;
   }
 
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 6c5d453..ff16f22 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1750,9 +1750,8 @@ void AsmPrinter::EmitComments(const MachineInstr &MI) const {
   O.PadToColumn(MAI->getCommentColumn());
   O << MAI->getCommentString() << " SrcLine ";
   if (DLT.CompileUnit) {
-    std::string Str;
     DICompileUnit CU(DLT.CompileUnit);
-    O << CU.getFilename(Str) << " ";
+    O << CU.getFilename() << " ";
   }
   O << DLT.Line;
   if (DLT.Col != 0) 
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index f9193ba..f667e31 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -570,9 +570,7 @@ 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());
-    std::string Name2;
-    DT.getName(Name2);
-    if (Name == Name2)
+    if (strcmp(Name.c_str(), DT.getName()) == 0)
       return (DT.getTypeDerivedFrom());
   }
 
@@ -648,8 +646,7 @@ void DwarfDebug::AddBlockByrefAddress(DbgVariable *&DV, DIE *Die,
   unsigned Tag = Ty.getTag();
   bool isPointer = false;
 
-  std::string varName;
-  VD.getName(varName);
+  const char *varName = VD.getName();
 
   if (Tag == dwarf::DW_TAG_pointer_type) {
     DIDerivedType DTy = DIDerivedType (Ty.getNode());
@@ -659,9 +656,6 @@ void DwarfDebug::AddBlockByrefAddress(DbgVariable *&DV, DIE *Die,
 
   DICompositeType blockStruct = DICompositeType(TmpTy.getNode());
 
-  std::string typeName;
-  blockStruct.getName(typeName);
-
   // Find the __forwarding field and the variable field in the __Block_byref
   // struct.
   DIArray Fields = blockStruct.getTypeArray();
@@ -672,11 +666,10 @@ 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());
-    std::string fieldName;
-    DT.getName(fieldName);
-    if (fieldName == "__forwarding")
+    const char *fieldName = DT.getName();
+    if (strcmp(fieldName, "__forwarding") == 0)
       forwardingField = Element;
-    else if (fieldName == varName)
+    else if (strcmp(fieldName, varName) == 0)
       varField = Element;
   }
 
@@ -823,14 +816,13 @@ void DwarfDebug::AddType(CompileUnit *DW_Unit, DIE *Entity, DIType Ty) {
 void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
                                   DIBasicType BTy) {
   // Get core information.
-  std::string Name;
-  BTy.getName(Name);
+  const char *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.empty())
+  if (Name)
     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);
@@ -840,8 +832,7 @@ void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
 void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
                                   DIDerivedType DTy) {
   // Get core information.
-  std::string Name;
-  DTy.getName(Name);
+  const char *Name = DTy.getName();
   uint64_t Size = DTy.getSizeInBits() >> 3;
   unsigned Tag = DTy.getTag();
 
@@ -855,7 +846,7 @@ void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
   AddType(DW_Unit, &Buffer, FromTy);
 
   // Add name if not anonymous or intermediate type.
-  if (!Name.empty())
+  if (Name)
     AddString(&Buffer, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
   // Add size if non-zero (derived types might be zero-sized.)
@@ -871,8 +862,7 @@ void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
 void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
                                   DICompositeType CTy) {
   // Get core information.
-  std::string Name;
-  CTy.getName(Name);
+  const char *Name = CTy.getName();
 
   uint64_t Size = CTy.getSizeInBits() >> 3;
   unsigned Tag = CTy.getTag();
@@ -952,7 +942,7 @@ void DwarfDebug::ConstructTypeDIE(CompileUnit *DW_Unit, DIE &Buffer,
   }
 
   // Add name if not anonymous or intermediate type.
-  if (!Name.empty())
+  if (Name)
     AddString(&Buffer, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
   if (Tag == dwarf::DW_TAG_enumeration_type ||
@@ -1018,8 +1008,7 @@ 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);
-  std::string Name;
-  ETy->getName(Name);
+  const char *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);
@@ -1030,12 +1019,11 @@ DIE *DwarfDebug::ConstructEnumTypeDIE(CompileUnit *DW_Unit, DIEnumerator *ETy) {
 DIE *DwarfDebug::CreateGlobalVariableDIE(CompileUnit *DW_Unit,
                                          const DIGlobalVariable &GV) {
   DIE *GVDie = new DIE(dwarf::DW_TAG_variable);
-  std::string Name;
-  GV.getDisplayName(Name);
-  AddString(GVDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
-  std::string LinkageName;
-  GV.getLinkageName(LinkageName);
-  if (!LinkageName.empty()) {
+  AddString(GVDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, 
+            GV.getDisplayName());
+
+  const char *LinkageName = GV.getLinkageName();
+  if (LinkageName) {
     // 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
@@ -1055,9 +1043,7 @@ 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());
-  std::string Name;
-  DT.getName(Name);
-  if (!Name.empty())
+  if (const char *Name = DT.getName())
     AddString(MemberDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
   AddType(DW_Unit, MemberDie, DT.getTypeDerivedFrom());
@@ -1106,13 +1092,11 @@ DIE *DwarfDebug::CreateSubprogramDIE(CompileUnit *DW_Unit,
                                      bool IsInlined) {
   DIE *SPDie = new DIE(dwarf::DW_TAG_subprogram);
 
-  std::string Name;
-  SP.getName(Name);
+  const char * Name = SP.getName();
   AddString(SPDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
-  std::string LinkageName;
-  SP.getLinkageName(LinkageName);
-  if (!LinkageName.empty()) {
+  const char *LinkageName = SP.getLinkageName();
+  if (LinkageName) {
     // 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.
@@ -1196,8 +1180,7 @@ DIE *DwarfDebug::CreateDbgScopeVariable(DbgVariable *DV, CompileUnit *Unit) {
 
   // Define variable debug information entry.
   DIE *VariableDie = new DIE(Tag);
-  std::string Name;
-  VD.getName(Name);
+  const char *Name = VD.getName();
   AddString(VariableDie, dwarf::DW_AT_name, dwarf::DW_FORM_string, Name);
 
   // Add source line info if available.
@@ -1398,8 +1381,8 @@ void DwarfDebug::ConstructDefaultDbgScope(MachineFunction *MF) {
 /// 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 std::string &DirName,
-                                         const std::string &FileName) {
+unsigned DwarfDebug::GetOrCreateSourceID(const char *DirName,
+                                         const char *FileName) {
   unsigned DId;
   StringMap<unsigned>::iterator DI = DirectoryIdMap.find(DirName);
   if (DI != DirectoryIdMap.end()) {
@@ -1434,28 +1417,26 @@ unsigned DwarfDebug::GetOrCreateSourceID(const std::string &DirName,
 
 void DwarfDebug::ConstructCompileUnit(MDNode *N) {
   DICompileUnit DIUnit(N);
-  std::string Dir, FN, Prod;
-  unsigned ID = GetOrCreateSourceID(DIUnit.getDirectory(Dir),
-                                    DIUnit.getFilename(FN));
+  const char *FN = DIUnit.getFilename();
+  const char *Dir = DIUnit.getDirectory();
+  unsigned ID = GetOrCreateSourceID(Dir, FN);
 
   DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
   AddSectionOffset(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
                    DWLabel("section_line", 0), DWLabel("section_line", 0),
                    false);
   AddString(Die, dwarf::DW_AT_producer, dwarf::DW_FORM_string,
-            DIUnit.getProducer(Prod));
+            DIUnit.getProducer());
   AddUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data1,
           DIUnit.getLanguage());
   AddString(Die, dwarf::DW_AT_name, dwarf::DW_FORM_string, FN);
 
-  if (!Dir.empty())
+  if (Dir)
     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);
 
-  std::string Flags;
-  DIUnit.getFlags(Flags);
-  if (!Flags.empty())
+  if (const char *Flags = DIUnit.getFlags())
     AddString(Die, dwarf::DW_AT_APPLE_flags, dwarf::DW_FORM_string, Flags);
 
   unsigned RVer = DIUnit.getRunTimeVersion();
@@ -1502,8 +1483,7 @@ void DwarfDebug::ConstructGlobalVariableDIE(MDNode *N) {
   ModuleCU->getDie()->AddChild(VariableDie);
 
   // Expose as global. FIXME - need to check external flag.
-  std::string Name;
-  ModuleCU->AddGlobal(DI_GV.getName(Name), VariableDie);
+  ModuleCU->AddGlobal(DI_GV.getName(), VariableDie);
   return;
 }
 
@@ -1529,8 +1509,7 @@ void DwarfDebug::ConstructSubprogram(MDNode *N) {
   ModuleCU->getDie()->AddChild(SubprogramDie);
 
   // Expose as global.
-  std::string Name;
-  ModuleCU->AddGlobal(SP.getName(Name), SubprogramDie);
+  ModuleCU->AddGlobal(SP.getName(), SubprogramDie);
   return;
 }
 
@@ -1801,9 +1780,8 @@ unsigned DwarfDebug::RecordSourceLine(unsigned Line, unsigned Col,
   if (TimePassesIsEnabled)
     DebugTimer->startTimer();
 
-  std::string Dir, Fn;
-  unsigned Src = GetOrCreateSourceID(CU.getDirectory(Dir),
-                                     CU.getFilename(Fn));
+  unsigned Src = GetOrCreateSourceID(CU.getDirectory(),
+                                     CU.getFilename());
   unsigned ID = MMI->NextLabelID();
   Lines.push_back(SrcLineInfo(Line, Col, Src, ID));
 
@@ -1823,7 +1801,7 @@ unsigned DwarfDebug::getOrCreateSourceID(const std::string &DirName,
   if (TimePassesIsEnabled)
     DebugTimer->startTimer();
 
-  unsigned SrcId = GetOrCreateSourceID(DirName, FileName);
+  unsigned SrcId = GetOrCreateSourceID(DirName.c_str(), FileName.c_str());
 
   if (TimePassesIsEnabled)
     DebugTimer->stopTimer();
@@ -2708,13 +2686,10 @@ void DwarfDebug::EmitDebugInlineInfo() {
     MDNode *Node = I->first;
     SmallVector<unsigned, 4> &Labels = I->second;
     DISubprogram SP(Node);
-    std::string Name;
-    std::string LName;
-
-    SP.getLinkageName(LName);
-    SP.getName(Name);
+    const char *LName = SP.getLinkageName();
+    const char *Name = SP.getName();
 
-    if (LName.empty())
+    if (!LName)
       Asm->EmitString(Name);
     else {
       // Skip special LLVM prefix that is used to inform the asm printer to not
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index d312eed..f582f9b 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -450,8 +450,8 @@ class VISIBILITY_HIDDEN 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 std::string &DirName,
-                               const std::string &FileName);
+  unsigned GetOrCreateSourceID(const char *DirName,
+                               const char *FileName);
 
   void ConstructCompileUnit(MDNode *N);
 
diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index ae6f3f5..3d1c221 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1041,9 +1041,8 @@ void MachineInstr::print(raw_ostream &OS, const TargetMachine *TM) const {
     const MachineFunction *MF = getParent()->getParent();
     DebugLocTuple DLT = MF->getDebugLocTuple(debugLoc);
     DICompileUnit CU(DLT.CompileUnit);
-    std::string Dir, Fn;
     OS << " [dbg: "
-       << CU.getDirectory(Dir) << '/' << CU.getFilename(Fn) << ","
+       << CU.getDirectory() << '/' << CU.getFilename() << ","
        << DLT.Line << ","
        << DLT.Col  << "]";
   }
diff --git a/lib/Target/PIC16/PIC16DebugInfo.cpp b/lib/Target/PIC16/PIC16DebugInfo.cpp
index 3499e5c..c32b659 100644
--- a/lib/Target/PIC16/PIC16DebugInfo.cpp
+++ b/lib/Target/PIC16/PIC16DebugInfo.cpp
@@ -44,8 +44,7 @@ void PIC16DbgInfo::PopulateDebugInfo (DIType Ty, unsigned short &TypeNo,
 /// PopulateBasicTypeInfo- Populate TypeNo for basic type from Ty.
 ///
 void PIC16DbgInfo::PopulateBasicTypeInfo (DIType Ty, unsigned short &TypeNo) {
-  std::string Name = "";
-  Ty.getName(Name);
+  std::string Name = Ty.getName();
   unsigned short BaseTy = GetTypeDebugNumber(Name);
   TypeNo = TypeNo << PIC16Dbg::S_BASIC;
   TypeNo = TypeNo | (0xffff & BaseTy);
@@ -117,7 +116,7 @@ void PIC16DbgInfo::PopulateStructOrUnionTypeInfo (DIType Ty,
     TypeNo = TypeNo | PIC16Dbg::T_STRUCT;
   else
     TypeNo = TypeNo | PIC16Dbg::T_UNION;
-  CTy.getName(TagName);
+  TagName = CTy.getName();
   // UniqueSuffix is .number where number is obtained from
   // llvm.dbg.composite<number>.
   // FIXME: This will break when composite type is not represented by
@@ -305,9 +304,8 @@ void PIC16DbgInfo::EmitCompositeTypeElements (DICompositeType CTy,
     bool HasAux = false;
     int ElementAux[PIC16Dbg::AuxSize] = { 0 };
     std::string TagName = "";
-    std::string ElementName;
     DIDerivedType DITy(Element.getNode());
-    DITy.getName(ElementName);
+    const char *ElementName = DITy.getName();
     unsigned short ElementSize = DITy.getSizeInBits()/8;
     // Get mangleddd name for this structure/union  element.
     std::string MangMemName = ElementName + SuffixNo;
@@ -338,8 +336,7 @@ void PIC16DbgInfo::EmitCompositeTypeDecls(Module &M) {
       continue;
     if (CTy.getTag() == dwarf::DW_TAG_union_type ||
         CTy.getTag() == dwarf::DW_TAG_structure_type ) {
-      std::string Name;
-      CTy.getName(Name);
+      const char *Name = CTy.getName();
       // Get the number after llvm.dbg.composite and make UniqueSuffix from 
       // it.
       std::string DIVar = CTy.getNode()->getNameStr();
@@ -468,9 +465,9 @@ void PIC16DbgInfo::EmitVarDebugInfo(Module &M) {
 void PIC16DbgInfo::SwitchToCU(MDNode *CU) {
   // Get the file path from CU.
   DICompileUnit cu(CU);
-  std::string DirName, FileName;
-  std::string FilePath = cu.getDirectory(DirName) + "/" + 
-                         cu.getFilename(FileName);
+  std::string DirName = cu.getDirectory();
+  std::string FileName = cu.getFilename();
+  std::string FilePath = DirName + "/" + FileName;
 
   // Nothing to do if source file is still same.
   if ( FilePath == CurFile ) return;