MCDwarf: Simplify MCDwarfFile to just use std::string instead of cunning use of MCContext's allocator.

There aren't /that/ many files, and we are already using various maps
and other standard containers that don't use MCContext's allocator to
store these values, so this doesn't seem to be critical and simplifies
the design (I'll be moving construction out of MCContext shortly so it'd
be annoying to have to pass the allocator around to allocate these
things... and we'll have non-MCContext users (debug_line.dwo) shortly)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203831 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 23 insertions, 29 deletions

diff --git a/include/llvm/MC/MCContext.h b/include/llvm/MC/MCContext.h
index cdd8f58bec..86578cc419 100644
--- a/include/llvm/MC/MCContext.h
+++ b/include/llvm/MC/MCContext.h
@@ -322,7 +322,7 @@ namespace llvm {
       return I->second;
     }
 
-    const SmallVectorImpl<MCDwarfFile *> &getMCDwarfFiles(unsigned CUID = 0) {
+    const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles(unsigned CUID = 0) {
       return getMCDwarfFileTable(CUID).getMCDwarfFiles();
     }
     const SmallVectorImpl<StringRef> &getMCDwarfDirs(unsigned CUID = 0) {
diff --git a/include/llvm/MC/MCDwarf.h b/include/llvm/MC/MCDwarf.h
index 7ad2ad0ff6..6ad26c4721 100644
--- a/include/llvm/MC/MCDwarf.h
+++ b/include/llvm/MC/MCDwarf.h
@@ -40,7 +40,7 @@ class SMLoc;
 struct MCDwarfFile {
   // Name - the base name of the file without its directory path.
   // The StringRef references memory allocated in the MCContext.
-  StringRef Name;
+  std::string Name;
 
   // DirIndex - the index into the list of directory names for this file name.
   unsigned DirIndex;
@@ -176,7 +176,7 @@ public:
 class MCDwarfFileTable {
   MCSymbol *Label;
   SmallVector<StringRef, 3> MCDwarfDirs;
-  SmallVector<MCDwarfFile *, 3> MCDwarfFiles;
+  SmallVector<MCDwarfFile, 3> MCDwarfFiles;
   MCLineSection MCLineSections;
 
 public:
@@ -197,11 +197,11 @@ public:
     return MCDwarfDirs;
   }
 
-  const SmallVectorImpl<MCDwarfFile *> &getMCDwarfFiles() const {
+  const SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles() const {
     return MCDwarfFiles;
   }
 
-  SmallVectorImpl<MCDwarfFile *> &getMCDwarfFiles() {
+  SmallVectorImpl<MCDwarfFile> &getMCDwarfFiles() {
     return MCDwarfFiles;
   }
 
diff --git a/lib/MC/MCContext.cpp b/lib/MC/MCContext.cpp
index 5ec5c35630..3c8de99712 100644
--- a/lib/MC/MCContext.cpp
+++ b/lib/MC/MCContext.cpp
@@ -338,20 +338,19 @@ const MCSectionCOFF *MCContext::getCOFFSection(StringRef Section) {
 unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
                                  unsigned FileNumber, unsigned CUID) {
   MCDwarfFileTable &Table = MCDwarfFileTablesCUMap[CUID];
-  SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = Table.getMCDwarfFiles();
+  SmallVectorImpl<MCDwarfFile>& MCDwarfFiles = Table.getMCDwarfFiles();
   SmallVectorImpl<StringRef>& MCDwarfDirs = Table.getMCDwarfDirs();
   // Make space for this FileNumber in the MCDwarfFiles vector if needed.
   if (FileNumber >= MCDwarfFiles.size()) {
     MCDwarfFiles.resize(FileNumber + 1);
-  } else {
-    MCDwarfFile *&ExistingFile = MCDwarfFiles[FileNumber];
-    if (ExistingFile)
-      // It is an error to use see the same number more than once.
-      return 0;
   }
 
   // Get the new MCDwarfFile slot for this FileNumber.
-  MCDwarfFile *&File = MCDwarfFiles[FileNumber];
+  MCDwarfFile &File = MCDwarfFiles[FileNumber];
+
+  // It is an error to use see the same number more than once.
+  if (!File.Name.empty())
+    return 0;
 
   if (Directory.empty()) {
     // Separate the directory part from the basename of the FileName.
@@ -387,13 +386,8 @@ unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
     DirIndex++;
   }
 
-  // Now make the MCDwarfFile entry and place it in the slot in the MCDwarfFiles
-  // vector.
-  char *Buf = static_cast<char *>(Allocate(FileName.size()));
-  memcpy(Buf, FileName.data(), FileName.size());
-  File = new (*this) MCDwarfFile;
-  File->Name = StringRef(Buf, FileName.size());
-  File->DirIndex = DirIndex;
+  File.Name = FileName;
+  File.DirIndex = DirIndex;
 
   // return the allocated FileNumber.
   return FileNumber;
@@ -402,11 +396,11 @@ unsigned MCContext::GetDwarfFile(StringRef Directory, StringRef FileName,
 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
 /// currently is assigned and false otherwise.
 bool MCContext::isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID) {
-  const SmallVectorImpl<MCDwarfFile *>& MCDwarfFiles = getMCDwarfFiles(CUID);
+  const SmallVectorImpl<MCDwarfFile>& MCDwarfFiles = getMCDwarfFiles(CUID);
   if(FileNumber == 0 || FileNumber >= MCDwarfFiles.size())
     return false;
 
-  return MCDwarfFiles[FileNumber] != 0;
+  return !MCDwarfFiles[FileNumber].Name.empty();
 }
 
 void MCContext::FatalError(SMLoc Loc, const Twine &Msg) {
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index d1e24fd65f..2c1874f5e9 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -289,10 +289,10 @@ const MCSymbol *MCDwarfFileTable::EmitCU(MCStreamer *MCOS) const {
 
   // Second the file table.
   for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
-    MCOS->EmitBytes(MCDwarfFiles[i]->Name); // FileName
+    MCOS->EmitBytes(MCDwarfFiles[i].Name); // FileName
     MCOS->EmitBytes(StringRef("\0", 1)); // the null term. of the string
     // the Directory num
-    MCOS->EmitULEB128IntValue(MCDwarfFiles[i]->DirIndex);
+    MCOS->EmitULEB128IntValue(MCDwarfFiles[i].DirIndex);
     MCOS->EmitIntValue(0, 1); // last modification timestamp (always 0)
     MCOS->EmitIntValue(0, 1); // filesize (always 0)
   }
@@ -602,9 +602,9 @@ static void EmitGenDwarfInfo(MCStreamer *MCOS,
     MCOS->EmitBytes(MCDwarfDirs[0]);
     MCOS->EmitBytes("/");
   }
-  const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles =
+  const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
     MCOS->getContext().getMCDwarfFiles();
-  MCOS->EmitBytes(MCDwarfFiles[1]->Name);
+  MCOS->EmitBytes(MCDwarfFiles[1].Name);
   MCOS->EmitIntValue(0, 1); // NULL byte to terminate the string.
 
   // AT_comp_dir, the working directory the assembly was done in.
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 889fb9dcb3..f3cf8f2d1c 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -662,10 +662,10 @@ bool AsmParser::Run(bool NoInitialTextSection, bool NoFinalize) {
     return TokError("unmatched .ifs or .elses");
 
   // Check to see there are no empty DwarfFile slots.
-  const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles =
+  const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
       getContext().getMCDwarfFiles();
   for (unsigned i = 1; i < MCDwarfFiles.size(); i++) {
-    if (!MCDwarfFiles[i])
+    if (MCDwarfFiles[i].Name.empty())
       TokError("unassigned file number: " + Twine(i) + " for .file directives");
   }
 
@@ -1589,10 +1589,10 @@ bool AsmParser::parseStatement(ParseStatementInfo &Info) {
     // If we previously parsed a cpp hash file line comment then make sure the
     // current Dwarf File is for the CppHashFilename if not then emit the
     // Dwarf File table for it and adjust the line number for the .loc.
-    const SmallVectorImpl<MCDwarfFile *> &MCDwarfFiles =
+    const SmallVectorImpl<MCDwarfFile> &MCDwarfFiles =
         getContext().getMCDwarfFiles();
     if (CppHashFilename.size() != 0) {
-      if (MCDwarfFiles[getContext().getGenDwarfFileNumber()]->Name !=
+      if (MCDwarfFiles[getContext().getGenDwarfFileNumber()].Name !=
           CppHashFilename)
         getStreamer().EmitDwarfFileDirective(
             getContext().nextGenDwarfFileNumber(), StringRef(),