Support: Add llvm::sys::fs::copy_file
A function to copy one file's contents to another.
llvm-svn: 211302
diff --git a/llvm/lib/Support/Path.cpp b/llvm/lib/Support/Path.cpp
index 15edf0dd..535394c 100644
--- a/llvm/lib/Support/Path.cpp
+++ b/llvm/lib/Support/Path.cpp
@@ -846,6 +846,40 @@
return create_directory(P, IgnoreExisting);
}
+std::error_code copy_file(const Twine &From, const Twine &To) {
+ int ReadFD, WriteFD;
+ if (std::error_code EC = openFileForRead(From, ReadFD))
+ return EC;
+ if (std::error_code EC = openFileForWrite(To, WriteFD, F_None)) {
+ close(ReadFD);
+ return EC;
+ }
+
+ const size_t BufSize = 4096;
+ char *Buf = new char[BufSize];
+ int BytesRead = 0, BytesWritten = 0;
+ for (;;) {
+ BytesRead = read(ReadFD, Buf, BufSize);
+ if (BytesRead <= 0)
+ break;
+ while (BytesRead) {
+ BytesWritten = write(WriteFD, Buf, BytesRead);
+ if (BytesWritten < 0)
+ break;
+ BytesRead -= BytesWritten;
+ }
+ if (BytesWritten < 0)
+ break;
+ }
+ close(ReadFD);
+ close(WriteFD);
+ delete[] Buf;
+
+ if (BytesRead < 0 || BytesWritten < 0)
+ return std::error_code(errno, std::generic_category());
+ return std::error_code();
+}
+
bool exists(file_status status) {
return status_known(status) && status.type() != file_type::file_not_found;
}