Add a pair of functions to hide system specific details of mapping a file in for reading.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13863 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/FileUtilities.cpp b/lib/Support/FileUtilities.cpp
index 1b8df43..74df8b2 100644
--- a/lib/Support/FileUtilities.cpp
+++ b/lib/Support/FileUtilities.cpp
@@ -14,8 +14,10 @@
#include "Support/FileUtilities.h"
#include "Config/unistd.h"
+#include "Config/fcntl.h"
#include "Config/sys/stat.h"
#include "Config/sys/types.h"
+#include "Config/sys/mman.h"
#include <fstream>
#include <iostream>
#include <cstdio>
@@ -215,8 +217,40 @@
return StatBuf.st_mtime;
}
+/// ReadFileIntoAddressSpace - Attempt to map the specific file into the
+/// address space of the current process for reading. If this succeeds,
+/// return the address of the buffer and the length of the file mapped. On
+/// failure, return null.
+void *llvm::ReadFileIntoAddressSpace(const std::string &Filename,
+ unsigned &Length) {
+#ifdef HAVE_MMAP_FILE
+ Length = getFileSize(Filename);
+ if ((int)Length == -1) return 0;
+ FDHandle FD(open(Filename.c_str(), O_RDONLY));
+ if (FD == -1) return 0;
+ // mmap in the file all at once...
+ void *Buffer = (void*)mmap(0, Length, PROT_READ, MAP_PRIVATE, FD, 0);
+
+ if (Buffer == (void*)MAP_FAILED)
+ return 0;
+ return Buffer;
+#else
+ // FIXME: implement with read/write
+ return 0;
+#endif
+}
+
+/// UnmapFileFromAddressSpace - Remove the specified file from the current
+/// address space.
+void llvm::UnmapFileFromAddressSpace(void *Buffer, unsigned Length) {
+#ifdef HAVE_MMAP_FILE
+ munmap((char*)Buffer, Length);
+#else
+ free(Buffer);
+#endif
+}
//===----------------------------------------------------------------------===//
// FDHandle class implementation