Revert "A third alternative."

This reverts commit f2654ae.

Author: johnno1962

lld/MachO/InputFiles.cpp

@@ -217,7 +217,8 @@ std::optional<MemoryBufferRef> macho::readFile(StringRef path) {
   if (entry != cachedReads.end())
     return entry->second;
 
-  ErrorOr<std::unique_ptr<MemoryBuffer>> mbOrErr = MemoryBuffer::getFile(path);
+  ErrorOr<std::unique_ptr<MemoryBuffer>> mbOrErr =
+      MemoryBuffer::getFile(path, false, /*RequiresNullTerminator=*/false);
   if (std::error_code ec = mbOrErr.getError()) {
     error("cannot open " + path + ": " + ec.message());
     return std::nullopt;

llvm/lib/Object/Archive.cpp

@@ -584,7 +584,8 @@ Expected<StringRef> Archive::Child::getBuffer() const {
   if (!FullNameOrErr)
     return FullNameOrErr.takeError();
   const std::string &FullName = *FullNameOrErr;
-  ErrorOr<std::unique_ptr<MemoryBuffer>> Buf = MemoryBuffer::getFile(FullName);
+  ErrorOr<std::unique_ptr<MemoryBuffer>> Buf =
+      MemoryBuffer::getFile(FullName, false, /*RequiresNullTerminator=*/false);
   if (std::error_code EC = Buf.getError())
     return errorCodeToError(EC);
   Parent->ThinBuffers.push_back(std::move(*Buf));

llvm/lib/Support/MemoryBuffer.cpp

@@ -266,9 +266,8 @@ MemoryBuffer::getFile(const Twine &Filename, bool IsText,
 template <typename MB>
 static ErrorOr<std::unique_ptr<MB>>
 getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
-                uint64_t MapSize, int64_t Offset, bool IsText,
-                bool RequiresNullTerminator, bool IsVolatile,
-                std::optional<Align> Alignment);
+                uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
+                bool IsVolatile, std::optional<Align> Alignment);
 
 template <typename MB>
 static ErrorOr<std::unique_ptr<MB>>
@@ -281,8 +280,7 @@ getFileAux(const Twine &Filename, uint64_t MapSize, uint64_t Offset,
     return errorToErrorCode(FDOrErr.takeError());
   sys::fs::file_t FD = *FDOrErr;
   auto Ret = getOpenFileImpl<MB>(FD, Filename, /*FileSize=*/-1, MapSize, Offset,
-                                 IsText, RequiresNullTerminator, IsVolatile,
-                                 Alignment);
+                                 RequiresNullTerminator, IsVolatile, Alignment);
   sys::fs::closeFile(FD);
   return Ret;
 }
@@ -470,9 +468,8 @@ WriteThroughMemoryBuffer::getFileSlice(const Twine &Filename, uint64_t MapSize,
 template <typename MB>
 static ErrorOr<std::unique_ptr<MB>>
 getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
-                uint64_t MapSize, int64_t Offset, bool IsText,
-                bool RequiresNullTerminator, bool IsVolatile,
-                std::optional<Align> Alignment) {
+                uint64_t MapSize, int64_t Offset, bool RequiresNullTerminator,
+                bool IsVolatile, std::optional<Align> Alignment) {
   static int PageSize = sys::Process::getPageSizeEstimate();
 
   // Default is to map the full file.
@@ -509,7 +506,7 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
       // from the page cache that are not properly filled with trailing zeroes,
       // if some prior user of the page wrote non-zero bytes. Detect this and
       // don't use mmap in that case.
-      if (!IsText || *Result->getBufferEnd() == '\0')
+      if (!RequiresNullTerminator || *Result->getBufferEnd() == '\0')
         return std::move(Result);
     }
   }
@@ -558,16 +555,16 @@ MemoryBuffer::getOpenFile(sys::fs::file_t FD, const Twine &Filename,
                           uint64_t FileSize, bool RequiresNullTerminator,
                           bool IsVolatile, std::optional<Align> Alignment) {
   return getOpenFileImpl<MemoryBuffer>(FD, Filename, FileSize, FileSize, 0,
-                                       false, RequiresNullTerminator,
-                                       IsVolatile, Alignment);
+                                       RequiresNullTerminator, IsVolatile,
+                                       Alignment);
 }
 
 ErrorOr<std::unique_ptr<MemoryBuffer>> MemoryBuffer::getOpenFileSlice(
     sys::fs::file_t FD, const Twine &Filename, uint64_t MapSize, int64_t Offset,
     bool IsVolatile, std::optional<Align> Alignment) {
   assert(MapSize != uint64_t(-1));
   return getOpenFileImpl<MemoryBuffer>(FD, Filename, -1, MapSize, Offset, false,
-                                       false, IsVolatile, Alignment);
+                                       IsVolatile, Alignment);
 }
 
 ErrorOr<std::unique_ptr<MemoryBuffer>> MemoryBuffer::getSTDIN() {