Support/FileSystem: Add copy_file implementation. Not tests yet because the
file creation APIs aren't implemented.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120593 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Unix/PathV2.inc b/lib/Support/Unix/PathV2.inc
index bcd93f0..d12cd16 100644
--- a/lib/Support/Unix/PathV2.inc
+++ b/lib/Support/Unix/PathV2.inc
@@ -17,6 +17,35 @@
//===----------------------------------------------------------------------===//
#include "Unix.h"
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+namespace {
+ struct AutoFD {
+ int FileDescriptor;
+
+ AutoFD(int fd) : FileDescriptor(fd) {}
+ ~AutoFD() {
+ if (FileDescriptor >= 0)
+ ::close(FileDescriptor);
+ }
+
+ int take() {
+ int ret = FileDescriptor;
+ FileDescriptor = -1;
+ return ret;
+ }
+
+ operator int() const {return FileDescriptor;}
+ };
+}
namespace llvm {
namespace sys {
@@ -35,5 +64,68 @@
}
} // end namespace path
+
+namespace fs{
+
+error_code copy_file(const Twine &from, const Twine &to, copy_option copt) {
+ // Get arguments.
+ SmallString<128> from_storage;
+ SmallString<128> to_storage;
+ StringRef f = from.toStringRef(from_storage);
+ StringRef t = to.toStringRef(to_storage);
+
+ const size_t buf_sz = 32768;
+ char buffer[buf_sz];
+ int from_file = -1, to_file = -1;
+
+ // Open from.
+ if ((from_file = ::open(f.begin(), O_RDONLY)) < 0)
+ return error_code(errno, system_category());
+ AutoFD from_fd(from_file);
+
+ // Stat from.
+ struct stat from_stat;
+ if (::stat(f.begin(), &from_stat) != 0)
+ return error_code(errno, system_category());
+
+ // Setup to flags.
+ int to_flags = O_CREAT | O_WRONLY;
+ if (copt == copy_option::fail_if_exists)
+ to_flags |= O_EXCL;
+
+ // Open to.
+ if ((to_file = ::open(t.begin(), to_flags, from_stat.st_mode)) < 0)
+ return error_code(errno, system_category());
+ AutoFD to_fd(to_file);
+
+ // Copy!
+ ssize_t sz, sz_read = 1, sz_write;
+ while (sz_read > 0 &&
+ (sz_read = ::read(from_fd, buffer, buf_sz)) > 0) {
+ // Allow for partial writes - see Advanced Unix Programming (2nd Ed.),
+ // Marc Rochkind, Addison-Wesley, 2004, page 94
+ sz_write = 0;
+ do {
+ if ((sz = ::write(to_fd, buffer + sz_write, sz_read - sz_write)) < 0) {
+ sz_read = sz; // cause read loop termination.
+ break; // error.
+ }
+ sz_write += sz;
+ } while (sz_write < sz_read);
+ }
+
+ // After all the file operations above the return value of close actually
+ // matters.
+ if (::close(from_fd.take()) < 0) sz_read = -1;
+ if (::close(to_fd.take()) < 0) sz_read = -1;
+
+ // Check for errors.
+ if (sz_read < 0)
+ return error_code(errno, system_category());
+
+ return make_error_code(errc::success);
+}
+
+} // end namespace fs
} // end namespace sys
} // end namespace llvm