Move reference files into their own directory

Readme.md

@@ -1,10 +1,9 @@
 # A writer for object file ar archives
 
-This is a Rust port of LLVM's archive writer (`ArchiveWriter.cpp`):
-* Based on commit [8ef3e895a](https://github.com/llvm/llvm-project/tree/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2) (15.0.0-rc3).
-* With the following options removed:
-  * Deterministic: always enabled.
-  * Symbol tables: always enabled.
+This is a Rust port of LLVM's archive writer (see [the LLVM Reference](reference/Readme.md)
+for details) with the following options removed:
+* Deterministic: always enabled.
+* Symbol tables: always enabled.
 
 ## License
 

src/Alignment.h → reference/Alignment.h

@@ -1,5 +1,3 @@
-// Copied from https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/include/llvm/Support/Alignment.h
-
 //===-- llvm/Support/Alignment.h - Useful alignment functions ---*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

src/Archive.h → reference/Archive.h

@@ -1,5 +1,3 @@
-// Copied from https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/include/llvm/Object/Archive.h
-
 //===- Archive.h - ar archive file format -----------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

src/ArchiveWriter.cpp → reference/ArchiveWriter.cpp

@@ -1,5 +1,3 @@
-// Copied from https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/lib/Object/ArchiveWriter.cpp
-
 //===- ArchiveWriter.cpp - ar File Format implementation --------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

src/ArchiveWriter.h → reference/ArchiveWriter.h

@@ -1,5 +1,3 @@
-// Copied from https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/include/llvm/Object/ArchiveWriter.h
-
 //===- ArchiveWriter.h - ar archive file format writer ----------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

reference/Readme.md

@@ -0,0 +1,18 @@
+# LLVM Reference Files
+
+These are a copy of the relevant LLVM files that were ported to Rust from the
+last time that this project was "synced" with LLVM.
+
+Currently that sync point is 15.0.0-rc3, commit [8ef3e895a](https://github.com/llvm/llvm-project/tree/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2).
+
+These files were originally located at:
+* `llvm/include/llvm/Support/Alignment.h`
+* `llvm/include/llvm/Object/Archive.h`
+* `llvm/include/llvm/Object/ArchiveWriter.h`
+* `llvm/lib/Object/ArchiveWriter.cpp`
+
+When syncing, make sure to update these files and the commit above.
+
+Additionally, `ar_archive_writer` has removed some options, so you can assume:
+* `deterministic` is always `true`.
+* `write_symtab` is always `true`.

src/alignment.rs

@@ -3,8 +3,6 @@
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-// Derived from https://github.com/llvm/llvm-project/blob/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3/llvm/include/llvm/Support/Alignment.h
-
 /// Returns a multiple of `align` needed to store `size` bytes.
 pub(crate) fn align_to(size: u64, align: u64) -> u64 {
     (size + align - 1) & !(align - 1)

src/archive.rs

@@ -3,8 +3,6 @@
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-// Derived from https://github.com/llvm/llvm-project/blob/8ef3e895ad8ab1724e2b87cabad1dacdc7a397a3/llvm/include/llvm/Object/Archive.h
-
 /// Size field is 10 decimal digits long
 pub(crate) const MAX_MEMBER_SIZE: u64 = 9999999999;
 

src/archive_writer.rs

@@ -5,10 +5,6 @@
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-// Derived from:
-// * https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/include/llvm/Object/ArchiveWriter.h
-// * https://github.com/llvm/llvm-project/blob/3d3ef9d073e1e27ea57480b371b7f5a9f5642ed2/llvm/lib/Object/ArchiveWriter.cpp
-
 use std::collections::HashMap;
 use std::io::{self, Cursor, Seek, Write};