Remove MappedFile support for mapping files for write and exec

and shared.  This complicates the design, is not used, and probably
doesn't even work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49022 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 23 insertions, 137 deletions

diff --git a/include/llvm/Debugger/SourceFile.h b/include/llvm/Debugger/SourceFile.h
index 11d2b0bdfa..eeff469c03 100644
--- a/include/llvm/Debugger/SourceFile.h
+++ b/include/llvm/Debugger/SourceFile.h
@@ -52,7 +52,7 @@ namespace llvm {
     SourceFile(const std::string &fn, const GlobalVariable *Desc)
       : Filename(fn), Descriptor(Desc), File() {
         std::string ErrMsg;
-      if (File.open(Filename, sys::MappedFile::READ_ACCESS, &ErrMsg))
+      if (File.open(Filename, &ErrMsg))
         throw ErrMsg;
       readFile();
     }
diff --git a/include/llvm/System/MappedFile.h b/include/llvm/System/MappedFile.h
index 6f902d28a1..82ed840332 100644
--- a/include/llvm/System/MappedFile.h
+++ b/include/llvm/System/MappedFile.h
@@ -25,26 +25,16 @@ namespace sys {
 
   /// This class provides an abstraction for a memory mapped file in the
   /// operating system's filesystem. It provides platform independent operations
-  /// for mapping a file into memory for both read and write access. This class
-  /// does not provide facilities for finding the file or operating on paths to
-  /// files. The sys::Path class is used for that.
+  /// for mapping a file into memory for both read access.
   class MappedFile {
     sys::PathWithStatus Path;        ///< Path to the file.
-    unsigned Options;                ///< Options used to create the mapping
     void *BasePtr;                   ///< Pointer to the base memory address
     mutable MappedFileInfo *MapInfo; ///< Platform specific info for the mapping
     
     MappedFile& operator=(const MappedFile &that); // DO NOT IMPLEMENT
     MappedFile(const MappedFile &that); // DO NOT IMPLEMENT
   public:
-    enum MappingOptions {
-      READ_ACCESS    = 0x0001,  ///< Map the file for reading
-      WRITE_ACCESS   = 0x0002,  ///< Map the file for write access
-      EXEC_ACCESS    = 0x0004,  ///< Map the file for execution access
-      SHARED_MAPPING = 0x0008   ///< Map the file shared with other processes
-    };
-    
-    MappedFile() : Options(READ_ACCESS), BasePtr(0), MapInfo(0) {}
+    MappedFile() : BasePtr(0), MapInfo(0) {}
 
     /// Destruct a MappedFile and release all memory associated with it.
     ~MappedFile() { close(); }
@@ -71,7 +61,7 @@ namespace sys {
     /// This function returns a reference to the sys::Path object kept by the
     /// MappedFile object. This contains the path to the file that is or
     /// will be mapped.
-    const sys::Path& path() const { return Path; }
+    const sys::PathWithStatus &path() const { return Path; }
 
     /// This function returns the number of bytes in the file.
     size_t size() const;
@@ -80,10 +70,8 @@ namespace sys {
     
     /// Open a file to be mapped and get its size but don't map it yet.  Return
     /// true on error.
-    bool open(const sys::Path &P, int options = READ_ACCESS,
-              std::string *ErrMsg = 0) {
+    bool open(const sys::Path &P, std::string *ErrMsg = 0) {
       Path = P;
-      Options = options;
       return initialize(ErrMsg);
     }
 
@@ -97,14 +85,6 @@ namespace sys {
     /// or 0 if an error occurred.
     void *map(std::string* ErrMsg = 0);
 
-    /// resize - This method causes the size of the file, and consequently the
-    /// size of the mapping to be set. This is logically the same as unmap(),
-    /// adjust size of the file, map(). Consequently, when calling this
-    /// function, the caller should not rely on previous results of the
-    /// map(), base(), or baseChar() members as they may point to invalid
-    /// areas of memory after this call.
-    bool resize(size_t new_size, std::string *ErrMsg = 0);
-
     void close() { if (MapInfo) terminate(); }
 
   private:
diff --git a/lib/Archive/Archive.cpp b/lib/Archive/Archive.cpp
index 125b22e9d9..c5da114538 100644
--- a/lib/Archive/Archive.cpp
+++ b/lib/Archive/Archive.cpp
@@ -148,7 +148,7 @@ bool
 Archive::mapToMemory(std::string* ErrMsg)
 {
   mapfile = new sys::MappedFile();
-  if (mapfile->open(archPath, sys::MappedFile::READ_ACCESS, ErrMsg))
+  if (mapfile->open(archPath, ErrMsg))
     return true;
   if (!(base = (char*) mapfile->map(ErrMsg)))
     return true;
diff --git a/lib/Archive/ArchiveWriter.cpp b/lib/Archive/ArchiveWriter.cpp
index c73e170ee7..6a71026a0f 100644
--- a/lib/Archive/ArchiveWriter.cpp
+++ b/lib/Archive/ArchiveWriter.cpp
@@ -212,7 +212,7 @@ Archive::writeMember(
   sys::MappedFile* mFile = 0;
   if (!data) {
     mFile = new sys::MappedFile();
-    if (mFile->open(member.getPath(), sys::MappedFile::READ_ACCESS, ErrMsg))
+    if (mFile->open(member.getPath(), ErrMsg))
       return true;
     if (!(data = (const char*) mFile->map(ErrMsg)))
       return true;
@@ -411,7 +411,7 @@ Archive::writeToDisk(bool CreateSymbolTable, bool TruncateNames, bool Compress,
 
     // Map in the archive we just wrote.
     sys::MappedFile arch;
-    if (arch.open(TmpArchive, sys::MappedFile::READ_ACCESS, ErrMsg))
+    if (arch.open(TmpArchive, ErrMsg))
       return true;
     const char* base;
     if (!(base = (const char*) arch.map(ErrMsg)))
diff --git a/lib/Support/FileUtilities.cpp b/lib/Support/FileUtilities.cpp
index cde08d188c..8cca9d96d9 100644
--- a/lib/Support/FileUtilities.cpp
+++ b/lib/Support/FileUtilities.cpp
@@ -192,10 +192,10 @@ int llvm::DiffFilesWithTolerance(const sys::PathWithStatus &FileA,
   // Now its safe to mmap the files into memory becasue both files
   // have a non-zero size.
   sys::MappedFile F1;
-  if (F1.open(FileA, sys::MappedFile::READ_ACCESS, Error))
+  if (F1.open(FileA, Error))
     return 2;
   sys::MappedFile F2;
-  if (F2.open(FileB, sys::MappedFile::READ_ACCESS, Error))
+  if (F2.open(FileB, Error))
     return 2;
   if (!F1.map(Error))
     return 2;
diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index 4d26d38731..8cea07fdb5 100644
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -159,7 +159,7 @@ bool MemoryBufferMMapFile::open(const sys::Path &Filename,
                                 std::string *ErrStr) {
   // FIXME: This does an extra stat syscall to figure out the size, but we
   // already know the size!
-  bool Failure = File.open(Filename, sys::MappedFile::READ_ACCESS, ErrStr);
+  bool Failure = File.open(Filename, ErrStr);
   if (Failure) return true;
   
   if (!File.map(ErrStr))
diff --git a/lib/System/Unix/MappedFile.inc b/lib/System/Unix/MappedFile.inc
index dcfd1892f8..92dc666043 100644
--- a/lib/System/Unix/MappedFile.inc
+++ b/lib/System/Unix/MappedFile.inc
@@ -1,4 +1,4 @@
-//===- Unix/MappedFile.cpp - Unix MappedFile Implementation -----*- C++ -*-===//
+//===- Unix/MappedFile.inc - Unix MappedFile Implementation -----*- C++ -*-===//
 // 
 //                     The LLVM Compiler Infrastructure
 //
@@ -11,11 +11,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only generic UNIX code that
-//===          is guaranteed to work on *all* UNIX variants.
-//===----------------------------------------------------------------------===//
-
 #include "Unix.h"
 #include "llvm/System/Process.h"
 
@@ -44,16 +39,7 @@ namespace llvm {
 }
 
 bool MappedFile::initialize(std::string* ErrMsg) {
-  int mode = 0;
-  if (Options & READ_ACCESS) 
-    if (Options & WRITE_ACCESS)
-      mode = O_RDWR;
-    else
-      mode = O_RDONLY;
-  else if (Options & WRITE_ACCESS)
-    mode = O_WRONLY;
-
-  int FD = ::open(Path.c_str(), mode);
+  int FD = ::open(Path.c_str(), O_RDONLY);
   if (FD < 0) {
     MakeErrMsg(ErrMsg, "can't open file '" + Path.toString() + "'");
     return true;
@@ -80,8 +66,6 @@ void MappedFile::unmap() {
   assert(MapInfo && "MappedFile not initialized");
   if (!isMapped()) return;
   
-  if (Options & WRITE_ACCESS)
-    ::msync(BasePtr, MapInfo->Size, MS_SYNC);
   ::munmap(BasePtr, MapInfo->Size);
   BasePtr = 0;  // Mark this as non-mapped.
 }
@@ -90,28 +74,13 @@ void* MappedFile::map(std::string* ErrMsg) {
   assert(MapInfo && "MappedFile not initialized");
   if (isMapped()) return BasePtr;
   
-  int prot = PROT_NONE;
-  int flags = 0;
+  int prot = PROT_READ;
+  int flags = MAP_PRIVATE;
 #ifdef MAP_FILE
   flags |= MAP_FILE;
 #endif
-  if (Options == 0) {
-    prot = PROT_READ;
-    flags = MAP_PRIVATE;
-  } else {
-    if (Options & READ_ACCESS)
-      prot |= PROT_READ;
-    if (Options & WRITE_ACCESS)
-      prot |= PROT_WRITE;
-    if (Options & EXEC_ACCESS)
-      prot |= PROT_EXEC;
-    if (Options & SHARED_MAPPING)
-      flags |= MAP_SHARED;
-    else
-      flags |= MAP_PRIVATE;
-  }
-  size_t map_size = ((MapInfo->Size / Process::GetPageSize())+1) *
-    Process::GetPageSize();
+  size_t PageSize = Process::GetPageSize();
+  size_t map_size = ((MapInfo->Size / PageSize)+1) * PageSize;
 
   BasePtr = ::mmap(0, map_size, prot, flags, MapInfo->FD, 0);
   if (BasePtr == MAP_FAILED) {
@@ -126,30 +95,3 @@ size_t MappedFile::size() const {
   return MapInfo->Size;
 }
 
-bool MappedFile::resize(size_t new_size, std::string* ErrMsg) {
-  assert(MapInfo && "MappedFile not initialized");
-
-  // Take the mapping out of memory
-  unmap();
-
-  // Adjust the current size to a page boundary
-  size_t cur_size = ((MapInfo->Size / Process::GetPageSize())+1) *
-    Process::GetPageSize();
-
-  // Adjust the new_size to a page boundary
-  new_size = ((new_size / Process::GetPageSize())+1) *
-    Process::GetPageSize();
-
-  // If the file needs to be extended
-  if (new_size > cur_size) {
-    // Ensure we can allocate at least the idodes necessary to handle the
-    // file size requested. 
-    if ((off_t)-1 == ::lseek(MapInfo->FD, new_size, SEEK_SET))
-      return MakeErrMsg(ErrMsg, "Can't lseek: ");
-    if (-1 == ::write(MapInfo->FD, "\0", 1))
-      return MakeErrMsg(ErrMsg, "Can't write: ");
-  }
-
-  // Put the mapping back into memory.
-  return map(ErrMsg);
-}
diff --git a/lib/System/Win32/MappedFile.inc b/lib/System/Win32/MappedFile.inc
index de8eec3673..830905debc 100644
--- a/lib/System/Win32/MappedFile.inc
+++ b/lib/System/Win32/MappedFile.inc
@@ -33,17 +33,13 @@ bool MappedFile::initialize(std::string* ErrMsg) {
   MapInfo->hFile = INVALID_HANDLE_VALUE;
   MapInfo->hMapping = NULL;
 
-  DWORD mode = Options & WRITE_ACCESS ? GENERIC_WRITE : GENERIC_READ;
-  DWORD disposition = Options & WRITE_ACCESS ? OPEN_ALWAYS : OPEN_EXISTING;
-  DWORD share = Options & WRITE_ACCESS ? FILE_SHARE_WRITE : FILE_SHARE_READ;
-  share = Options & SHARED_MAPPING ? share : 0;
-  MapInfo->hFile = CreateFile(Path.c_str(), mode, share, NULL, disposition,
-                            FILE_ATTRIBUTE_NORMAL, NULL);
+  MapInfo->hFile = CreateFile(Path.c_str(), GENERIC_READ, 0, NULL,
+                              OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
   if (MapInfo->hFile == INVALID_HANDLE_VALUE) {
     delete MapInfo;
     MapInfo = NULL;
     return MakeErrMsg(ErrMsg,
-      std::string("Can't open file: ") + Path.toString());
+                      std::string("Can't open file: ") + Path.toString());
   }
 
   LARGE_INTEGER size;
@@ -81,19 +77,14 @@ void MappedFile::unmap() {
 
 void* MappedFile::map(std::string* ErrMsg) {
   if (!isMapped()) {
-    DWORD prot = PAGE_READONLY;
-    if (Options & EXEC_ACCESS)
-      prot = SEC_IMAGE;
-    else if (Options & WRITE_ACCESS)
-      prot = PAGE_READWRITE;
-    MapInfo->hMapping = CreateFileMapping(MapInfo->hFile, NULL, prot, 0, 0, NULL);
+    MapInfo->hMapping = CreateFileMapping(MapInfo->hFile, NULL, PAGE_READONLY,
+                                          0, 0, NULL);
     if (MapInfo->hMapping == NULL) {
       MakeErrMsg(ErrMsg, std::string("Can't map file: ") + Path.toString());
       return 0;
     }
 
-    prot = (Options & WRITE_ACCESS) ? FILE_MAP_WRITE : FILE_MAP_READ;
-    BasePtr = MapViewOfFileEx(MapInfo->hMapping, prot, 0, 0, 0, NULL);
+    BasePtr = MapViewOfFileEx(MapInfo->hMapping, FILE_MAP_READ, 0, 0, 0, NULL);
     if (BasePtr == NULL) {
       CloseHandle(MapInfo->hMapping);
       MapInfo->hMapping = NULL;
@@ -109,32 +100,5 @@ size_t MappedFile::size() const {
   return MapInfo->size;
 }
 
-bool MappedFile::resize(size_t new_size, std::string* ErrMsg) {
-  assert(MapInfo && "MappedFile not initialized");
-
-  // Take the mapping out of memory.
-  unmap();
-
-  // Adjust the new_size to a page boundary.
-  size_t pagesizem1 = Process::GetPageSize() - 1;
-  new_size = (new_size + pagesizem1) & ~pagesizem1;
-
-  // If the file needs to be extended, do so.
-  if (new_size > MapInfo->size) {
-    LARGE_INTEGER eof;
-    eof.QuadPart = new_size;
-    if (!SetFilePointerEx(MapInfo->hFile, eof, NULL, FILE_BEGIN))
-      return MakeErrMsg(ErrMsg, 
-        std::string("Can't set end of file: ") + Path.toString());
-    if (!SetEndOfFile(MapInfo->hFile))
-      return MakeErrMsg(ErrMsg, 
-        std::string("Can't set end of file: ") + Path.toString());
-    MapInfo->size = new_size;
-  }
-
-  // Remap the file.
-  return map(ErrMsg);
-}
-
 }