MemoryBuffer now return an error_code and returns a OwningPtr<MemoryBuffer> via an out parm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121958 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Archive/Archive.cpp b/lib/Archive/Archive.cpp
index 3ce7fbd..20d9dee 100644
--- a/lib/Archive/Archive.cpp
+++ b/lib/Archive/Archive.cpp
@@ -148,13 +148,13 @@
 
 bool
 Archive::mapToMemory(std::string* ErrMsg) {
-  error_code ec;
-  mapfile = MemoryBuffer::getFile(archPath.c_str(), ec);
-  if (mapfile == 0) {
+  OwningPtr<MemoryBuffer> File;
+  if (error_code ec = MemoryBuffer::getFile(archPath.c_str(), File)) {
     if (ErrMsg)
       *ErrMsg = ec.message();
     return true;
   }
+  mapfile = File.take();
   base = mapfile->getBufferStart();
   return false;
 }
@@ -218,10 +218,8 @@
                              LLVMContext& Context,
                              std::vector<std::string>& symbols,
                              std::string* ErrMsg) {
-  error_code ec;
-  std::auto_ptr<MemoryBuffer> Buffer(
-                       MemoryBuffer::getFileOrSTDIN(fName.c_str(), ec));
-  if (!Buffer.get()) {
+  OwningPtr<MemoryBuffer> Buffer;
+  if (error_code ec = MemoryBuffer::getFileOrSTDIN(fName.c_str(), Buffer)) {
     if (ErrMsg) *ErrMsg = "Could not open file '" + fName.str() + "'" + ": "
                         + ec.message();
     return true;
@@ -246,7 +244,7 @@
                         std::vector<std::string>& symbols,
                         std::string* ErrMsg) {
   // Get the module.
-  std::auto_ptr<MemoryBuffer> Buffer(
+  OwningPtr<MemoryBuffer> Buffer(
     MemoryBuffer::getMemBufferCopy(StringRef(BufPtr, Length),ModuleID.c_str()));
   
   Module *M = ParseBitcodeFile(Buffer.get(), Context, ErrMsg);
diff --git a/lib/Archive/ArchiveWriter.cpp b/lib/Archive/ArchiveWriter.cpp
index e9222c5..07516c6 100644
--- a/lib/Archive/ArchiveWriter.cpp
+++ b/lib/Archive/ArchiveWriter.cpp
@@ -213,13 +213,13 @@
   const char *data = (const char*)member.getData();
   MemoryBuffer *mFile = 0;
   if (!data) {
-    error_code ec;
-    mFile = MemoryBuffer::getFile(member.getPath().c_str(), ec);
-    if (mFile == 0) {
+    OwningPtr<MemoryBuffer> File;
+    if (error_code ec = MemoryBuffer::getFile(member.getPath().c_str(), File)) {
       if (ErrMsg)
         *ErrMsg = ec.message();
       return true;
     }
+    mFile = File.take();
     data = mFile->getBufferStart();
     fSize = mFile->getBufferSize();
   }
@@ -411,9 +411,8 @@
 
     // Map in the archive we just wrote.
     {
-    error_code ec;
-    OwningPtr<MemoryBuffer> arch(MemoryBuffer::getFile(TmpArchive.c_str(), ec));
-    if (arch == 0) {
+    OwningPtr<MemoryBuffer> arch;
+    if (error_code ec = MemoryBuffer::getFile(TmpArchive.c_str(), arch)) {
       if (ErrMsg)
         *ErrMsg = ec.message();
       return true;
diff --git a/lib/AsmParser/Parser.cpp b/lib/AsmParser/Parser.cpp
index a613a83..59fb471 100644
--- a/lib/AsmParser/Parser.cpp
+++ b/lib/AsmParser/Parser.cpp
@@ -42,15 +42,14 @@
 
 Module *llvm::ParseAssemblyFile(const std::string &Filename, SMDiagnostic &Err,
                                 LLVMContext &Context) {
-  error_code ec;
-  MemoryBuffer *F = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), ec);
-  if (F == 0) {
+  OwningPtr<MemoryBuffer> File;
+  if (error_code ec = MemoryBuffer::getFileOrSTDIN(Filename.c_str(), File)) {
     Err = SMDiagnostic(Filename,
                        "Could not open input file: " + ec.message());
     return 0;
   }
 
-  return ParseAssembly(F, 0, Err, Context);
+  return ParseAssembly(File.take(), 0, Err, Context);
 }
 
 Module *llvm::ParseAssemblyString(const char *AsmString, Module *M,
diff --git a/lib/Linker/LinkItems.cpp b/lib/Linker/LinkItems.cpp
index 7716b61..52a0d17 100644
--- a/lib/Linker/LinkItems.cpp
+++ b/lib/Linker/LinkItems.cpp
@@ -161,14 +161,13 @@
   // Check for a file of name "-", which means "read standard input"
   if (File.str() == "-") {
     std::auto_ptr<Module> M;
+    OwningPtr<MemoryBuffer> Buffer;
     error_code ec;
-    if (MemoryBuffer *Buffer = MemoryBuffer::getSTDIN(ec)) {
+    if (!(ec = MemoryBuffer::getSTDIN(Buffer))) {
       if (!Buffer->getBufferSize()) {
-        delete Buffer;
         Error = "standard input is empty";
       } else {
-        M.reset(ParseBitcodeFile(Buffer, Context, &Error));
-        delete Buffer;
+        M.reset(ParseBitcodeFile(Buffer.get(), Context, &Error));
         if (M.get())
           if (!LinkInModule(M.get(), &Error))
             return false;
diff --git a/lib/Linker/Linker.cpp b/lib/Linker/Linker.cpp
index 9606d06..fba91da 100644
--- a/lib/Linker/Linker.cpp
+++ b/lib/Linker/Linker.cpp
@@ -99,14 +99,12 @@
   std::string ParseErrorMessage;
   Module *Result = 0;
 
-  error_code ec;
-  std::auto_ptr<MemoryBuffer> Buffer(
-    MemoryBuffer::getFileOrSTDIN(FN.c_str(), ec));
-  if (Buffer.get())
-    Result = ParseBitcodeFile(Buffer.get(), Context, &ParseErrorMessage);
-  else
+  OwningPtr<MemoryBuffer> Buffer;
+  if (error_code ec = MemoryBuffer::getFileOrSTDIN(FN.c_str(), Buffer))
     ParseErrorMessage = "Error reading file '" + FN.str() + "'" + ": "
                       + ec.message();
+  else
+    Result = ParseBitcodeFile(Buffer.get(), Context, &ParseErrorMessage);
 
   if (Result)
     return std::auto_ptr<Module>(Result);
diff --git a/lib/Object/ObjectFile.cpp b/lib/Object/ObjectFile.cpp
index 2a6e086..aa483f3 100644
--- a/lib/Object/ObjectFile.cpp
+++ b/lib/Object/ObjectFile.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/ADT/OwningPtr.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
@@ -63,6 +64,8 @@
 }
 
 ObjectFile *ObjectFile::createObjectFile(StringRef ObjectPath) {
-  error_code ec;
-  return createObjectFile(MemoryBuffer::getFile(ObjectPath, ec));
+  OwningPtr<MemoryBuffer> File;
+  if (error_code ec = MemoryBuffer::getFile(ObjectPath, File))
+    return NULL;
+  return createObjectFile(File.take());
 }
diff --git a/lib/Support/CommandLine.cpp b/lib/Support/CommandLine.cpp
index e856509..373a1a2 100644
--- a/lib/Support/CommandLine.cpp
+++ b/lib/Support/CommandLine.cpp
@@ -464,11 +464,6 @@
       const sys::FileStatus *FileStat = respFile.getFileStatus();
       if (FileStat && FileStat->getSize() != 0) {
 
-        // Mmap the response file into memory.
-        error_code ec;
-        OwningPtr<MemoryBuffer>
-          respFilePtr(MemoryBuffer::getFile(respFile.c_str(), ec));
-
         // If we could open the file, parse its contents, otherwise
         // pass the @file option verbatim.
 
@@ -477,7 +472,9 @@
         // itself contain additional @file options; any such options will be
         // processed recursively.")
 
-        if (respFilePtr != 0) {
+        // Mmap the response file into memory.
+        OwningPtr<MemoryBuffer> respFilePtr;
+        if (!MemoryBuffer::getFile(respFile.c_str(), respFilePtr)) {
           ParseCStringVector(newArgv, respFilePtr->getBufferStart());
           continue;
         }
diff --git a/lib/Support/FileUtilities.cpp b/lib/Support/FileUtilities.cpp
index c9e42e9..5dbabee 100644
--- a/lib/Support/FileUtilities.cpp
+++ b/lib/Support/FileUtilities.cpp
@@ -201,14 +201,14 @@
   // Now its safe to mmap the files into memory becasue both files
   // have a non-zero size.
   error_code ec;
-  OwningPtr<MemoryBuffer> F1(MemoryBuffer::getFile(FileA.c_str(), ec));
-  if (F1 == 0) {
+  OwningPtr<MemoryBuffer> F1;
+  if (error_code ec = MemoryBuffer::getFile(FileA.c_str(), F1)) {
     if (Error)
       *Error = ec.message();
     return 2;
   }
-  OwningPtr<MemoryBuffer> F2(MemoryBuffer::getFile(FileB.c_str(), ec));
-  if (F2 == 0) {
+  OwningPtr<MemoryBuffer> F2;
+  if (error_code ec = MemoryBuffer::getFile(FileB.c_str(), F2)) {
     if (Error)
       *Error = ec.message();
     return 2;
diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index 0966f90..d3c71b9 100644
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -35,6 +35,8 @@
 #include <fcntl.h>
 using namespace llvm;
 
+namespace { const llvm::error_code success; }
+
 //===----------------------------------------------------------------------===//
 // MemoryBuffer implementation itself.
 //===----------------------------------------------------------------------===//
@@ -143,20 +145,20 @@
 /// if the Filename is "-".  If an error occurs, this returns null and fills
 /// in *ErrStr with a reason.  If stdin is empty, this API (unlike getSTDIN)
 /// returns an empty buffer.
-MemoryBuffer *MemoryBuffer::getFileOrSTDIN(StringRef Filename,
-                                           error_code &ec,
-                                           int64_t FileSize) {
+error_code MemoryBuffer::getFileOrSTDIN(StringRef Filename,
+                                        OwningPtr<MemoryBuffer> &result,
+                                        int64_t FileSize) {
   if (Filename == "-")
-    return getSTDIN(ec);
-  return getFile(Filename, ec, FileSize);
+    return getSTDIN(result);
+  return getFile(Filename, result, FileSize);
 }
 
-MemoryBuffer *MemoryBuffer::getFileOrSTDIN(const char *Filename,
-                                           error_code &ec,
-                                           int64_t FileSize) {
+error_code MemoryBuffer::getFileOrSTDIN(const char *Filename,
+                                        OwningPtr<MemoryBuffer> &result,
+                                        int64_t FileSize) {
   if (strcmp(Filename, "-") == 0)
-    return getSTDIN(ec);
-  return getFile(Filename, ec, FileSize);
+    return getSTDIN(result);
+  return getFile(Filename, result, FileSize);
 }
 
 //===----------------------------------------------------------------------===//
@@ -186,30 +188,32 @@
 };
 }
 
-MemoryBuffer *MemoryBuffer::getFile(StringRef Filename, error_code &ec,
-                                    int64_t FileSize) {
+error_code MemoryBuffer::getFile(StringRef Filename,
+                                 OwningPtr<MemoryBuffer> &result,
+                                 int64_t FileSize) {
   // Ensure the path is null terminated.
   SmallString<256> PathBuf(Filename.begin(), Filename.end());
-  return MemoryBuffer::getFile(PathBuf.c_str(), ec, FileSize);
+  return MemoryBuffer::getFile(PathBuf.c_str(), result, FileSize);
 }
 
-MemoryBuffer *MemoryBuffer::getFile(const char *Filename, error_code &ec,
-                                    int64_t FileSize) {
+error_code MemoryBuffer::getFile(const char *Filename,
+                                 OwningPtr<MemoryBuffer> &result,
+                                 int64_t FileSize) {
   int OpenFlags = O_RDONLY;
 #ifdef O_BINARY
   OpenFlags |= O_BINARY;  // Open input file in binary mode on win32.
 #endif
   int FD = ::open(Filename, OpenFlags);
   if (FD == -1) {
-    ec = error_code(errno, posix_category());
-    return 0;
+    return error_code(errno, posix_category());
   }
 
-  return getOpenFile(FD, Filename, ec, FileSize);
+  return getOpenFile(FD, Filename, result, FileSize);
 }
 
-MemoryBuffer *MemoryBuffer::getOpenFile(int FD, const char *Filename,
-                                        error_code &ec, int64_t FileSize) {
+error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
+                                     OwningPtr<MemoryBuffer> &result,
+                                     int64_t FileSize) {
   FileCloser FC(FD); // Close FD on return.
 
   // If we don't know the file size, use fstat to find out.  fstat on an open
@@ -218,8 +222,7 @@
     struct stat FileInfo;
     // TODO: This should use fstat64 when available.
     if (fstat(FD, &FileInfo) == -1) {
-      ec = error_code(errno, posix_category());
-      return 0;
+      return error_code(errno, posix_category());
     }
     FileSize = FileInfo.st_size;
   }
@@ -234,8 +237,9 @@
   if (FileSize >= 4096*4 &&
       (FileSize & (sys::Process::GetPageSize()-1)) != 0) {
     if (const char *Pages = sys::Path::MapInFilePages(FD, FileSize)) {
-      return GetNamedBuffer<MemoryBufferMMapFile>(StringRef(Pages, FileSize),
-                                                  Filename);
+      result.reset(GetNamedBuffer<MemoryBufferMMapFile>(
+        StringRef(Pages, FileSize), Filename));
+      return success;
     }
   }
 
@@ -243,8 +247,7 @@
   if (!Buf) {
     // Failed to create a buffer. The only way it can fail is if
     // new(std::nothrow) returns 0.
-    ec = make_error_code(errc::not_enough_memory);
-    return 0;
+    return make_error_code(errc::not_enough_memory);
   }
 
   OwningPtr<MemoryBuffer> SB(Buf);
@@ -257,26 +260,27 @@
       if (errno == EINTR)
         continue;
       // Error while reading.
-      ec = error_code(errno, posix_category());
-      return 0;
+      return error_code(errno, posix_category());
     } else if (NumRead == 0) {
       // We hit EOF early, truncate and terminate buffer.
       Buf->BufferEnd = BufPtr;
       *BufPtr = 0;
-      return SB.take();
+      result.swap(SB);
+      return success;
     }
     BytesLeft -= NumRead;
     BufPtr += NumRead;
   }
 
-  return SB.take();
+  result.swap(SB);
+  return success;
 }
 
 //===----------------------------------------------------------------------===//
 // MemoryBuffer::getSTDIN implementation.
 //===----------------------------------------------------------------------===//
 
-MemoryBuffer *MemoryBuffer::getSTDIN(error_code &ec) {
+error_code MemoryBuffer::getSTDIN(OwningPtr<MemoryBuffer> &result) {
   // Read in all of the data from stdin, we cannot mmap stdin.
   //
   // FIXME: That isn't necessarily true, we should try to mmap stdin and
@@ -292,11 +296,11 @@
     ReadBytes = read(0, Buffer.end(), ChunkSize);
     if (ReadBytes == -1) {
       if (errno == EINTR) continue;
-      ec = error_code(errno, posix_category());
-      return 0;
+      return error_code(errno, posix_category());
     }
     Buffer.set_size(Buffer.size() + ReadBytes);
   } while (ReadBytes != 0);
 
-  return getMemBufferCopy(Buffer, "<stdin>");
+  result.reset(getMemBufferCopy(Buffer, "<stdin>"));
+  return success;
 }
diff --git a/lib/Support/SourceMgr.cpp b/lib/Support/SourceMgr.cpp
index 1f62068..ef09916 100644
--- a/lib/Support/SourceMgr.cpp
+++ b/lib/Support/SourceMgr.cpp
@@ -16,6 +16,7 @@
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/ADT/OwningPtr.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/system_error.h"
 using namespace llvm;
@@ -49,18 +50,18 @@
 /// ~0, otherwise it returns the buffer ID of the stacked file.
 unsigned SourceMgr::AddIncludeFile(const std::string &Filename,
                                    SMLoc IncludeLoc) {
-  error_code ec;
-  MemoryBuffer *NewBuf = MemoryBuffer::getFile(Filename.c_str(), ec);
+  OwningPtr<MemoryBuffer> NewBuf;
+  MemoryBuffer::getFile(Filename.c_str(), NewBuf);
 
   // If the file didn't exist directly, see if it's in an include path.
   for (unsigned i = 0, e = IncludeDirectories.size(); i != e && !NewBuf; ++i) {
     std::string IncFile = IncludeDirectories[i] + "/" + Filename;
-    NewBuf = MemoryBuffer::getFile(IncFile.c_str(), ec);
+    MemoryBuffer::getFile(IncFile.c_str(), NewBuf);
   }
 
   if (NewBuf == 0) return ~0U;
 
-  return AddNewSourceBuffer(NewBuf, IncludeLoc);
+  return AddNewSourceBuffer(NewBuf.take(), IncludeLoc);
 }
 
 
diff --git a/lib/VMCore/Core.cpp b/lib/VMCore/Core.cpp
index a4c77a2..6bad2f3 100644
--- a/lib/VMCore/Core.cpp
+++ b/lib/VMCore/Core.cpp
@@ -2221,9 +2221,10 @@
     LLVMMemoryBufferRef *OutMemBuf,
     char **OutMessage) {
 
+  OwningPtr<MemoryBuffer> MB;
   error_code ec;
-  if (MemoryBuffer *MB = MemoryBuffer::getFile(Path, ec)) {
-    *OutMemBuf = wrap(MB);
+  if (!(ec = MemoryBuffer::getFile(Path, MB))) {
+    *OutMemBuf = wrap(MB.take());
     return 0;
   }
 
@@ -2233,9 +2234,10 @@
 
 LLVMBool LLVMCreateMemoryBufferWithSTDIN(LLVMMemoryBufferRef *OutMemBuf,
                                          char **OutMessage) {
+  OwningPtr<MemoryBuffer> MB;
   error_code ec;
-  if (MemoryBuffer *MB = MemoryBuffer::getSTDIN(ec)) {
-    *OutMemBuf = wrap(MB);
+  if (!(ec = MemoryBuffer::getSTDIN(MB))) {
+    *OutMemBuf = wrap(MB.take());
     return 0;
   }