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)

llvm-svn: 203831

3 files changed, 18 insertions, 24 deletions

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 5ec5c35630c..3c8de997124 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/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/llvm/lib/MC/MCDwarf.cpp b/llvm/lib/MC/MCDwarf.cpp
index d1e24fd65f0..2c1874f5e91 100644
--- a/llvm/lib/MC/MCDwarf.cpp
+++ b/llvm/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/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
index 889fb9dcb34..f3cf8f2d1c7 100644
--- a/llvm/lib/MC/MCParser/AsmParser.cpp
+++ b/llvm/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(),