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.

llvm-svn: 142300

7 files changed, 75 insertions, 33 deletions

diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
index 3fcbb05907b..d90f7b2ad2d 100644
--- a/llvm/lib/MC/MCAsmStreamer.cpp
+++ b/llvm/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/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 82690ee3b3e..9e28b8f41c6 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/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/llvm/lib/MC/MCLoggingStreamer.cpp b/llvm/lib/MC/MCLoggingStreamer.cpp
index 3fe8ac72c8e..a7b79476767 100644
--- a/llvm/lib/MC/MCLoggingStreamer.cpp
+++ b/llvm/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/llvm/lib/MC/MCNullStreamer.cpp b/llvm/lib/MC/MCNullStreamer.cpp
index a6c0adb6793..d178b507a0f 100644
--- a/llvm/lib/MC/MCNullStreamer.cpp
+++ b/llvm/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/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 50fa4d4d7ba..4e8e15c7d6c 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/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/llvm/lib/MC/MCPureStreamer.cpp b/llvm/lib/MC/MCPureStreamer.cpp
index 086c9229bcd..1a2a92e3293 100644
--- a/llvm/lib/MC/MCPureStreamer.cpp
+++ b/llvm/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/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 3afa22b0d0b..2a37f82a518 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/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,