Add support for a new extension to the .file directive:

  .file filenumber "directory" "filename"

This removes one join+split of the directory+filename in MC internals. Because
bitcode files have independent fields for directory and filenames in debug info,
this patch may change the .o files written by existing .bc files.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142300 91177308-0d34-0410-b5e6-96231b3b80d8

22 files changed, 144 insertions, 66 deletions

diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h
index a49a35c8d5..44bfb39c64 100644
--- a/include/llvm/MC/MCContext.h
+++ b/include/llvm/MC/MCContext.h
@@ -204,7 +204,8 @@ namespace llvm {
     /// @{
 
     /// GetDwarfFile - creates an entry in the dwarf file and directory tables.
-    unsigned GetDwarfFile(StringRef FileName, unsigned FileNumber);
+    unsigned GetDwarfFile(StringRef Directory, StringRef FileName,
+                          unsigned FileNumber);
 
     bool isValidDwarfFileNumber(unsigned FileNumber);
 
diff --git a/include/llvm/MC/MCStreamer.h b/include/llvm/MC/MCStreamer.h
index 451efbff6e..59ce70d9e5 100644
--- a/include/llvm/MC/MCStreamer.h
+++ b/include/llvm/MC/MCStreamer.h
@@ -505,7 +505,8 @@ namespace llvm {
     /// EmitDwarfFileDirective - Associate a filename with a specified logical
     /// file number.  This implements the DWARF2 '.file 4 "foo.c"' assembler
     /// directive.
-    virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename);
+    virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                        StringRef Filename);
 
     /// EmitDwarfLocDirective - This implements the DWARF2
     // '.loc fileno lineno ...' assembler directive.
@@ -613,6 +614,7 @@ namespace llvm {
                                 bool isVerboseAsm,
                                 bool useLoc,
                                 bool useCFI,
+                                bool useDwarfDirectory,
                                 MCInstPrinter *InstPrint = 0,
                                 MCCodeEmitter *CE = 0,
                                 MCAsmBackend *TAB = 0,
diff --git a/include/llvm/Support/TargetRegistry.h b/include/llvm/Support/TargetRegistry.h
index 45f249d7ed..bf3b7ba24f 100644
--- a/include/llvm/Support/TargetRegistry.h
+++ b/include/llvm/Support/TargetRegistry.h
@@ -50,6 +50,7 @@ namespace llvm {
   MCStreamer *createAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
                                 bool isVerboseAsm,
                                 bool useLoc, bool useCFI,
+                                bool useDwarfDirectory,
                                 MCInstPrinter *InstPrint,
                                 MCCodeEmitter *CE,
                                 MCAsmBackend *TAB,
@@ -116,6 +117,7 @@ namespace llvm {
                                              bool isVerboseAsm,
                                              bool useLoc,
                                              bool useCFI,
+                                             bool useDwarfDirectory,
                                              MCInstPrinter *InstPrint,
                                              MCCodeEmitter *CE,
                                              MCAsmBackend *TAB,
@@ -426,13 +428,14 @@ namespace llvm {
                                   bool isVerboseAsm,
                                   bool useLoc,
                                   bool useCFI,
+                                  bool useDwarfDirectory,
                                   MCInstPrinter *InstPrint,
                                   MCCodeEmitter *CE,
                                   MCAsmBackend *TAB,
                                   bool ShowInst) const {
       // AsmStreamerCtorFn is default to llvm::createAsmStreamer
       return AsmStreamerCtorFn(Ctx, OS, isVerboseAsm, useLoc, useCFI,
-                               InstPrint, CE, TAB, ShowInst);
+                               useDwarfDirectory, InstPrint, CE, TAB, ShowInst);
     }
 
     /// @}
diff --git a/include/llvm/Target/TargetMachine.h b/include/llvm/Target/TargetMachine.h
index 8a8d142290..30c5b3ac64 100644
--- a/include/llvm/Target/TargetMachine.h
+++ b/include/llvm/Target/TargetMachine.h
@@ -101,6 +101,7 @@ protected: // Can only create subclasses.
   unsigned MCSaveTempLabels : 1;
   unsigned MCUseLoc : 1;
   unsigned MCUseCFI : 1;
+  unsigned MCUseDwarfDirectory : 1;
 
 public:
   virtual ~TargetMachine();
@@ -196,6 +197,14 @@ public:
   /// setMCUseCFI - Set whether all we should use dwarf's .cfi_* directives.
   void setMCUseCFI(bool Value) { MCUseCFI = Value; }
 
+  /// hasMCUseDwarfDirectory - Check whether we should use .file directives with
+  /// explicit directories.
+  bool hasMCUseDwarfDirectory() const { return MCUseDwarfDirectory; }
+
+  /// setMCUseDwarfDirectory - Set whether all we should use .file directives
+  /// with explicit directories.
+  void setMCUseDwarfDirectory(bool Value) { MCUseDwarfDirectory = Value; }
+
   /// getRelocationModel - Returns the code generation relocation model. The
   /// choices are static, PIC, and dynamic-no-pic, and target default.
   Reloc::Model getRelocationModel() const;
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 1b7e370fca..9978c829ba 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -442,23 +442,21 @@ unsigned DwarfDebug::GetOrCreateSourceID(StringRef FileName,
   if (FileName.empty())
     return GetOrCreateSourceID("<stdin>", StringRef());
 
-  // MCStream expects full path name as filename.
-  if (!DirName.empty() && !sys::path::is_absolute(FileName)) {
-    SmallString<128> FullPathName = DirName;
-    sys::path::append(FullPathName, FileName);
-    // Here FullPathName will be copied into StringMap by GetOrCreateSourceID.
-    return GetOrCreateSourceID(StringRef(FullPathName), StringRef());
-  }
-
-  StringMapEntry<unsigned> &Entry = SourceIdMap.GetOrCreateValue(FileName);
-  if (Entry.getValue())
-    return Entry.getValue();
-
-  unsigned SrcId = SourceIdMap.size();
-  Entry.setValue(SrcId);
+  unsigned SrcId = SourceIdMap.size()+1;
+  std::pair<std::string, std::string> SourceName =
+      std::make_pair(FileName, DirName);
+  std::pair<std::pair<std::string, std::string>, unsigned> Entry =
+      make_pair(SourceName, SrcId);
+
+  std::map<std::pair<std::string, std::string>, unsigned>::iterator I;
+  bool NewlyInserted;
+  tie(I, NewlyInserted) = SourceIdMap.insert(Entry);
+  if (!NewlyInserted)
+    return I->second;
 
   // Print out a .file directive to specify files for .loc directives.
-  Asm->OutStreamer.EmitDwarfFileDirective(SrcId, Entry.getKey());
+  Asm->OutStreamer.EmitDwarfFileDirective(SrcId, Entry.first.second,
+                                          Entry.first.first);
 
   return SrcId;
 }
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 35653be5c8..faa78f3e48 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -26,6 +26,7 @@
 #include "llvm/ADT/UniqueVector.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/DebugLoc.h"
+#include <map>
 
 namespace llvm {
 
@@ -207,9 +208,9 @@ class DwarfDebug {
   ///
   std::vector<DIEAbbrev *> Abbreviations;
 
-  /// SourceIdMap - Source id map, i.e. pair of directory id and source file
-  /// id mapped to a unique id.
-  StringMap<unsigned> SourceIdMap;
+  /// SourceIdMap - Source id map, i.e. pair of source filename and directory
+  /// mapped to a unique id.
+  std::map<std::pair<std::string, std::string>, unsigned> SourceIdMap;
 
   /// StringPool - A String->Symbol mapping of strings used by indirect
   /// references.
diff --git a/lib/CodeGen/LLVMTargetMachine.cpp b/lib/CodeGen/LLVMTargetMachine.cpp
index 80ecc22481..759610a082 100644
--- a/lib/CodeGen/LLVMTargetMachine.cpp
+++ b/lib/CodeGen/LLVMTargetMachine.cpp
@@ -159,6 +159,7 @@ bool LLVMTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
                                                   getVerboseAsm(),
                                                   hasMCUseLoc(),
                                                   hasMCUseCFI(),
+                                                  hasMCUseDwarfDirectory(),
                                                   InstPrinter,
                                                   MCE, MAB,
                                                   ShowMCInst);
diff --git a/lib/MC/MCAsmStreamer.cpp b/lib/MC/MCAsmStreamer.cpp
index 3fcbb05907..d90f7b2ad2 100644
--- a/lib/MC/MCAsmStreamer.cpp
+++ b/lib/MC/MCAsmStreamer.cpp
@@ -29,6 +29,7 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/PathV2.h"
 #include <cctype>
 using namespace llvm;
 
@@ -50,6 +51,7 @@ private:
   unsigned ShowInst : 1;
   unsigned UseLoc : 1;
   unsigned UseCFI : 1;
+  unsigned UseDwarfDirectory : 1;
 
   enum EHSymbolFlags { EHGlobal         = 1,
                        EHWeakDefinition = 1 << 1,
@@ -63,13 +65,15 @@ private:
 public:
   MCAsmStreamer(MCContext &Context, formatted_raw_ostream &os,
                 bool isVerboseAsm, bool useLoc, bool useCFI,
+                bool useDwarfDirectory,
                 MCInstPrinter *printer, MCCodeEmitter *emitter,
                 MCAsmBackend *asmbackend,
                 bool showInst)
     : MCStreamer(Context), OS(os), MAI(Context.getAsmInfo()),
       InstPrinter(printer), Emitter(emitter), AsmBackend(asmbackend),
       CommentStream(CommentToEmit), IsVerboseAsm(isVerboseAsm),
-      ShowInst(showInst), UseLoc(useLoc), UseCFI(useCFI) {
+      ShowInst(showInst), UseLoc(useLoc), UseCFI(useCFI),
+      UseDwarfDirectory(useDwarfDirectory) {
     if (InstPrinter && IsVerboseAsm)
       InstPrinter->setCommentStream(CommentStream);
   }
@@ -196,7 +200,8 @@ public:
                                  unsigned char Value = 0);
 
   virtual void EmitFileDirective(StringRef Filename);
-  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
+  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                      StringRef Filename);
   virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
                                      unsigned Column, unsigned Flags,
                                      unsigned Isa, unsigned Discriminator,
@@ -748,13 +753,27 @@ void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
   EmitEOL();
 }
 
-bool MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Filename){
+bool MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                           StringRef Filename) {
+  if (!UseDwarfDirectory && !Directory.empty()) {
+    if (sys::path::is_absolute(Filename))
+      return EmitDwarfFileDirective(FileNo, "", Filename);
+
+    SmallString<128> FullPathName = Directory;
+    sys::path::append(FullPathName, Filename);
+    return EmitDwarfFileDirective(FileNo, "", FullPathName);
+  }
+
   if (UseLoc) {
     OS << "\t.file\t" << FileNo << ' ';
+    if (!Directory.empty()) {
+      PrintQuotedString(Directory, OS);
+      OS << ' ';
+    }
     PrintQuotedString(Filename, OS);
     EmitEOL();
   }
-  return this->MCStreamer::EmitDwarfFileDirective(FileNo, Filename);
+  return this->MCStreamer::EmitDwarfFileDirective(FileNo, Directory, Filename);
 }
 
 void MCAsmStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
@@ -1271,9 +1290,9 @@ void MCAsmStreamer::Finish() {
 MCStreamer *llvm::createAsmStreamer(MCContext &Context,
                                     formatted_raw_ostream &OS,
                                     bool isVerboseAsm, bool useLoc,
-                                    bool useCFI, MCInstPrinter *IP,
-                                    MCCodeEmitter *CE, MCAsmBackend *MAB,
-                                    bool ShowInst) {
+                                    bool useCFI, bool useDwarfDirectory,
+                                    MCInstPrinter *IP, MCCodeEmitter *CE,
+                                    MCAsmBackend *MAB, bool ShowInst) {
   return new MCAsmStreamer(Context, OS, isVerboseAsm, useLoc, useCFI,
-                           IP, CE, MAB, ShowInst);
+                           useDwarfDirectory, IP, CE, MAB, ShowInst);
 }
diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index 82690ee3b3..9e28b8f41c 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -248,7 +248,8 @@ const MCSection *MCContext::getCOFFSection(StringRef Section,
 /// directory tables.  If the file number has already been allocated it is an
 /// error and zero is returned and the client reports the error, else the
 /// allocated file number is returned.  The file numbers may be in any order.
-unsigned MCContext::GetDwarfFile(StringRef FileName, unsigned FileNumber) {
+unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
+                                 unsigned FileNumber) {
   // TODO: a FileNumber of zero says to use the next available file number.
   // Note: in GenericAsmParser::ParseDirectiveFile() FileNumber was checked
   // to not be less than one.  This needs to be change to be not less than zero.
@@ -266,19 +267,21 @@ unsigned MCContext::GetDwarfFile(StringRef FileName, unsigned FileNumber) {
   // Get the new MCDwarfFile slot for this FileNumber.
   MCDwarfFile *&File = MCDwarfFiles[FileNumber];
 
-  // Separate the directory part from the basename of the FileName.
-  std::pair<StringRef, StringRef> Slash = FileName.rsplit('/');
+  if (Directory.empty()) {
+    // Separate the directory part from the basename of the FileName.
+    std::pair<StringRef, StringRef> Slash = FileName.rsplit('/');
+    Directory = Slash.second;
+    if (!Directory.empty())
+      FileName = Slash.first;
+  }
 
   // Find or make a entry in the MCDwarfDirs vector for this Directory.
-  StringRef Name;
-  unsigned DirIndex;
   // Capture directory name.
-  if (Slash.second.empty()) {
-    Name = Slash.first;
-    DirIndex = 0; // For FileNames with no directories a DirIndex of 0 is used.
+  unsigned DirIndex;
+  if (Directory.empty()) {
+    // For FileNames with no directories a DirIndex of 0 is used.
+    DirIndex = 0;
   } else {
-    StringRef Directory = Slash.first;
-    Name = Slash.second;
     DirIndex = 0;
     for (unsigned End = MCDwarfDirs.size(); DirIndex < End; DirIndex++) {
       if (Directory == MCDwarfDirs[DirIndex])
@@ -291,16 +294,16 @@ unsigned MCContext::GetDwarfFile(StringRef FileName, unsigned FileNumber) {
     }
     // The DirIndex is one based, as DirIndex of 0 is used for FileNames with
     // no directories.  MCDwarfDirs[] is unlike MCDwarfFiles[] in that the
-    // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames are
-    // stored at MCDwarfFiles[FileNumber].Name .
+    // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
+    // are stored at MCDwarfFiles[FileNumber].Name .
     DirIndex++;
   }
 
   // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
   // vector.
-  char *Buf = static_cast<char *>(Allocate(Name.size()));
-  memcpy(Buf, Name.data(), Name.size());
-  File = new (*this) MCDwarfFile(StringRef(Buf, Name.size()), DirIndex);
+  char *Buf = static_cast<char *>(Allocate(FileName.size()));
+  memcpy(Buf, FileName.data(), FileName.size());
+  File = new (*this) MCDwarfFile(StringRef(Buf, FileName.size()), DirIndex);
 
   // return the allocated FileNumber.
   return FileNumber;
diff --git a/lib/MC/MCLoggingStreamer.cpp b/lib/MC/MCLoggingStreamer.cpp
index 3fe8ac72c8..a7b7947676 100644
--- a/lib/MC/MCLoggingStreamer.cpp
+++ b/lib/MC/MCLoggingStreamer.cpp
@@ -208,10 +208,12 @@ public:
     return Child->EmitFileDirective(Filename);
   }
 
-  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
+  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                      StringRef Filename) {
     LogCall("EmitDwarfFileDirective",
-            "FileNo:" + Twine(FileNo) + " Filename:" + Filename);
-    return Child->EmitDwarfFileDirective(FileNo, Filename);
+            "FileNo:" + Twine(FileNo) + " Directory:" + Directory +
+            " Filename:" + Filename);
+    return Child->EmitDwarfFileDirective(FileNo, Directory, Filename);
   }
 
   virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
diff --git a/lib/MC/MCNullStreamer.cpp b/lib/MC/MCNullStreamer.cpp
index a6c0adb679..d178b507a0 100644
--- a/lib/MC/MCNullStreamer.cpp
+++ b/lib/MC/MCNullStreamer.cpp
@@ -83,7 +83,8 @@ namespace {
                                    unsigned char Value = 0) {}
     
     virtual void EmitFileDirective(StringRef Filename) {}
-    virtual bool EmitDwarfFileDirective(unsigned FileNo,StringRef Filename) {
+    virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                        StringRef Filename) {
       return false;
     }
     virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 50fa4d4d7b..4e8e15c7d6 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -2303,7 +2303,8 @@ bool AsmParser::ParseDirectiveEndIf(SMLoc DirectiveLoc) {
 }
 
 /// ParseDirectiveFile
-/// ::= .file [number] string
+/// ::= .file [number] filename
+/// ::= .file number directory filename
 bool GenericAsmParser::ParseDirectiveFile(StringRef, SMLoc DirectiveLoc) {
   // FIXME: I'm not sure what this is.
   int64_t FileNumber = -1;
@@ -2319,17 +2320,31 @@ bool GenericAsmParser::ParseDirectiveFile(StringRef, SMLoc DirectiveLoc) {
   if (getLexer().isNot(AsmToken::String))
     return TokError("unexpected token in '.file' directive");
 
-  StringRef Filename = getTok().getString();
-  Filename = Filename.substr(1, Filename.size()-2);
+  // Usually the directory and filename together, otherwise just the directory.
+  StringRef Path = getTok().getString();
+  Path = Path.substr(1, Path.size()-2);
   Lex();
 
+  StringRef Directory;
+  StringRef Filename;
+  if (getLexer().is(AsmToken::String)) {
+    if (FileNumber == -1)
+      return TokError("explicit path specified, but no file number");
+    Filename = getTok().getString();
+    Filename = Filename.substr(1, Filename.size()-2);
+    Directory = Path;
+    Lex();
+  } else {
+    Filename = Path;
+  }
+
   if (getLexer().isNot(AsmToken::EndOfStatement))
     return TokError("unexpected token in '.file' directive");
 
   if (FileNumber == -1)
     getStreamer().EmitFileDirective(Filename);
   else {
-    if (getStreamer().EmitDwarfFileDirective(FileNumber, Filename))
+    if (getStreamer().EmitDwarfFileDirective(FileNumber, Directory, Filename))
       Error(FileNumberLoc, "file number already allocated");
   }
 
diff --git a/lib/MC/MCPureStreamer.cpp b/lib/MC/MCPureStreamer.cpp
index 086c9229bc..1a2a92e329 100644
--- a/lib/MC/MCPureStreamer.cpp
+++ b/lib/MC/MCPureStreamer.cpp
@@ -93,7 +93,8 @@ public:
   virtual void EmitFileDirective(StringRef Filename) {
     report_fatal_error("unsupported directive in pure streamer");
   }
-  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Filename) {
+  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                      StringRef Filename) {
     report_fatal_error("unsupported directive in pure streamer");
     return false;
   }
diff --git a/lib/MC/MCStreamer.cpp b/lib/MC/MCStreamer.cpp
index 3afa22b0d0..2a37f82a51 100644
--- a/lib/MC/MCStreamer.cpp
+++ b/lib/MC/MCStreamer.cpp
@@ -142,8 +142,9 @@ void MCStreamer::EmitFill(uint64_t NumBytes, uint8_t FillValue,
 }
 
 bool MCStreamer::EmitDwarfFileDirective(unsigned FileNo,
+                                        StringRef Directory,
                                         StringRef Filename) {
-  return getContext().GetDwarfFile(Filename, FileNo) == 0;
+  return getContext().GetDwarfFile(Directory, Filename, FileNo) == 0;
 }
 
 void MCStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
diff --git a/lib/Target/PTX/PTXAsmPrinter.cpp b/lib/Target/PTX/PTXAsmPrinter.cpp
index 733744bbd0..b2aa7b27ed 100644
--- a/lib/Target/PTX/PTXAsmPrinter.cpp
+++ b/lib/Target/PTX/PTXAsmPrinter.cpp
@@ -535,7 +535,7 @@ unsigned PTXAsmPrinter::GetOrCreateSourceID(StringRef FileName,
   Entry.setValue(SrcId);
 
   // Print out a .file directive to specify files for .loc directives.
-  OutStreamer.EmitDwarfFileDirective(SrcId, Entry.getKey());
+  OutStreamer.EmitDwarfFileDirective(SrcId, "", Entry.getKey());
 
   return SrcId;
 }
@@ -594,4 +594,3 @@ extern "C" void LLVMInitializePTXAsmPrinter() {
   RegisterAsmPrinter<PTXAsmPrinter> X(ThePTX32Target);
   RegisterAsmPrinter<PTXAsmPrinter> Y(ThePTX64Target);
 }
-
diff --git a/lib/Target/PTX/PTXMCAsmStreamer.cpp b/lib/Target/PTX/PTXMCAsmStreamer.cpp
index 468ce9301d..bc7aaa3e41 100644
--- a/lib/Target/PTX/PTXMCAsmStreamer.cpp
+++ b/lib/Target/PTX/PTXMCAsmStreamer.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/FormattedStream.h"
+#include "llvm/Support/PathV2.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
@@ -165,7 +166,8 @@ public:
                                  unsigned char Value = 0);
 
   virtual void EmitFileDirective(StringRef Filename);
-  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Filename);
+  virtual bool EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
+                                      StringRef Filename);
 
   virtual void EmitInstruction(const MCInst &Inst);
 
@@ -489,11 +491,20 @@ void PTXMCAsmStreamer::EmitFileDirective(StringRef Filename) {
 
 // FIXME: should we inherit from MCAsmStreamer?
 bool PTXMCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo,
-                                              StringRef Filename){
+                                              StringRef Directory,
+                                              StringRef Filename) {
+  if (!Directory.empty()) {
+    if (sys::path::is_absolute(Filename))
+      return EmitDwarfFileDirective(FileNo, "", Filename);
+    SmallString<128> FullPathName = Directory;
+    sys::path::append(FullPathName, Filename);
+    return EmitDwarfFileDirective(FileNo, "", FullPathName);
+  }
+
   OS << "\t.file\t" << FileNo << ' ';
   PrintQuotedString(Filename, OS);
   EmitEOL();
-  return this->MCStreamer::EmitDwarfFileDirective(FileNo, Filename);
+  return this->MCStreamer::EmitDwarfFileDirective(FileNo, Directory, Filename);
 }
 
 void PTXMCAsmStreamer::AddEncodingComment(const MCInst &Inst) {}
@@ -535,6 +546,7 @@ namespace llvm {
   MCStreamer *createPTXAsmStreamer(MCContext &Context,
                                    formatted_raw_ostream &OS,
                                    bool isVerboseAsm, bool useLoc, bool useCFI,
+                                   bool useDwarfDirectory,
                                    MCInstPrinter *IP,
                                    MCCodeEmitter *CE, MCAsmBackend *MAB,
                                    bool ShowInst) {
diff --git a/lib/Target/PTX/PTXTargetMachine.cpp b/lib/Target/PTX/PTXTargetMachine.cpp
index 449a3d9fc8..50dd417752 100644
--- a/lib/Target/PTX/PTXTargetMachine.cpp
+++ b/lib/Target/PTX/PTXTargetMachine.cpp
@@ -46,7 +46,7 @@ using namespace llvm;
 namespace llvm {
   MCStreamer *createPTXAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
                                    bool isVerboseAsm, bool useLoc,
-                                   bool useCFI,
+                                   bool useCFI, bool useDwarfDirectory,
                                    MCInstPrinter *InstPrint,
                                    MCCodeEmitter *CE,
                                    MCAsmBackend *MAB,
@@ -157,6 +157,7 @@ bool PTXTargetMachine::addPassesToEmitFile(PassManagerBase &PM,
                                                   true, /* verbose asm */
                                                   hasMCUseLoc(),
                                                   hasMCUseCFI(),
+                                                  hasMCUseDwarfDirectory(),
                                                   InstPrinter,
                                                   MCE, MAB,
                                                   false /* show MC encoding */);
diff --git a/lib/Target/TargetMachine.cpp b/lib/Target/TargetMachine.cpp
index fe8a7cebd0..3f58e84390 100644
--- a/lib/Target/TargetMachine.cpp
+++ b/lib/Target/TargetMachine.cpp
@@ -197,7 +197,8 @@ TargetMachine::TargetMachine(const Target &T,
     MCNoExecStack(false),
     MCSaveTempLabels(false),
     MCUseLoc(true),
-    MCUseCFI(true) {
+    MCUseCFI(true),
+    MCUseDwarfDirectory(true) {
   // Typically it will be subtargets that will adjust FloatABIType from Default
   // to Soft or Hard.
   if (UseSoftFloat)
diff --git a/test/CodeGen/X86/dbg-file-name.ll b/test/CodeGen/X86/dbg-file-name.ll
index 3a849aa543..138ee264bf 100644
--- a/test/CodeGen/X86/dbg-file-name.ll
+++ b/test/CodeGen/X86/dbg-file-name.ll
@@ -1,7 +1,7 @@
 ; RUN: llc -mtriple x86_64-apple-darwin10.0.0  < %s | FileCheck %s
 
 ; Radar 8884898
-; CHECK: file	1 "/Users/manav/one/two{{/|\\\\}}simple.c"
+; CHECK: file	1 "/Users/manav/one/two" "simple.c"
 
 declare i32 @printf(i8*, ...) nounwind
 
diff --git a/test/MC/AsmParser/directive_file.s b/test/MC/AsmParser/directive_file.s
index 3160d5c2bf..121890e69a 100644
--- a/test/MC/AsmParser/directive_file.s
+++ b/test/MC/AsmParser/directive_file.s
@@ -2,7 +2,8 @@
 
         .file "hello"
         .file 1 "world"
+        .file 2 "directory" "file"
 
 # CHECK: .file "hello"
 # CHECK: .file 1 "world"
-
+# CHECK: .file 2 "directory" "file"
diff --git a/tools/llc/llc.cpp b/tools/llc/llc.cpp
index 7211954c30..4cb3cf1cb9 100644
--- a/tools/llc/llc.cpp
+++ b/tools/llc/llc.cpp
@@ -133,6 +133,9 @@ cl::opt<bool> DisableDotLoc("disable-dot-loc", cl::Hidden,
 cl::opt<bool> DisableCFI("disable-cfi", cl::Hidden,
                          cl::desc("Do not use .cfi_* directives"));
 
+cl::opt<bool> DisableDwarfDirectory("disable-dwarf-directory", cl::Hidden,
+    cl::desc("Do not use file directives with an explicit directory."));
+
 static cl::opt<bool>
 DisableRedZone("disable-red-zone",
   cl::desc("Do not emit code that uses the red zone."),
@@ -316,6 +319,9 @@ int main(int argc, char **argv) {
   if (DisableCFI)
     Target.setMCUseCFI(false);
 
+  if (DisableDwarfDirectory)
+    Target.setMCUseDwarfDirectory(false);
+
   // Disable .loc support for older OS X versions.
   if (TheTriple.isMacOSX() &&
       TheTriple.isMacOSXVersionLT(10, 6))
diff --git a/tools/llvm-mc/llvm-mc.cpp b/tools/llvm-mc/llvm-mc.cpp
index ce4a5b355a..280a1bbd99 100644
--- a/tools/llvm-mc/llvm-mc.cpp
+++ b/tools/llvm-mc/llvm-mc.cpp
@@ -409,8 +409,10 @@ static int AssembleInput(const char *ProgName) {
     }
     Str.reset(TheTarget->createAsmStreamer(Ctx, FOS, /*asmverbose*/true,
                                            /*useLoc*/ true,
-                                           /*useCFI*/ true, IP, CE, MAB,
-                                           ShowInst));
+                                           /*useCFI*/ true,
+                                           /*useDwarfDirectory*/ true,
+                                           IP, CE, MAB, ShowInst));
+                                           
   } else if (FileType == OFT_Null) {
     Str.reset(createNullStreamer(Ctx));
   } else {
@@ -515,4 +517,3 @@ int main(int argc, char **argv) {
 
   return 0;
 }
-