From 67f4911ab8fc6add5e852454e4b49a96e546d72b Mon Sep 17 00:00:00 2001
From: Alexander O'Mara <me@alexomara.com>
Date: Mon, 20 Jan 2025 14:07:32 -0500
Subject: [PATCH] Added MachOImage

---
 macho/machoimage.test.ts | 31 +++++++++++++++++++++++++++++
 macho/machoimage.ts      | 42 ++++++++++++++++++++++++++++++++++++++++
 macho/mod.ts             |  1 +
 3 files changed, 74 insertions(+)
 create mode 100644 macho/machoimage.test.ts
 create mode 100644 macho/machoimage.ts

diff --git a/macho/machoimage.test.ts b/macho/machoimage.test.ts
new file mode 100644
index 0000000..38f8c98
--- /dev/null
+++ b/macho/machoimage.test.ts
@@ -0,0 +1,31 @@
+import { assertEquals, assertStrictEquals } from '@std/assert';
+import { MH_MAGIC } from '../const.ts';
+import { LoadCommand } from '../mach/loadcommand.ts';
+import { MachHeader } from '../mach/machheader.ts';
+import { MachOImage } from './machoimage.ts';
+
+Deno.test('constructor', () => {
+	const buffer = new ArrayBuffer(
+		MachHeader.BYTE_LENGTH + LoadCommand.BYTE_LENGTH,
+	);
+	const header = new MachHeader(buffer);
+	header.magic = MH_MAGIC;
+	header.ncmds = 1;
+	header.sizeofcmds = LoadCommand.BYTE_LENGTH;
+
+	{
+		const macho = new MachOImage(buffer);
+		const address = macho.address();
+		assertEquals(address.byteOffset, 0);
+		assertStrictEquals(address.buffer, buffer);
+	}
+
+	{
+		const data = new Uint8Array(buffer.byteLength + 2);
+		data.subarray(1).set(new Uint8Array(buffer));
+		const macho = new MachOImage(data.subarray(1));
+		const address = macho.address();
+		assertEquals(address.byteOffset, 1);
+		assertStrictEquals(address.buffer, data.buffer);
+	}
+});
diff --git a/macho/machoimage.ts b/macho/machoimage.ts
new file mode 100644
index 0000000..cefe7f7
--- /dev/null
+++ b/macho/machoimage.ts
@@ -0,0 +1,42 @@
+import type { ArrayBufferReal, BufferPointer } from '@hqtsm/struct';
+import { MachOBase } from './machobase.ts';
+
+/**
+ * A Mach-O binary over a buffer.
+ */
+export class MachOImage extends MachOBase {
+	declare public readonly ['constructor']: Omit<typeof MachOImage, 'new'>;
+
+	/**
+	 * Construct a Mach-O binary over a buffer.
+	 *
+	 * @param address Buffer pointer.
+	 */
+	constructor(address: ArrayBufferReal | BufferPointer) {
+		super();
+
+		this.initHeader(address);
+
+		let buffer;
+		let byteOffset = this.headerSize();
+		if ('buffer' in address) {
+			buffer = address.buffer;
+			byteOffset += address.byteOffset;
+		} else {
+			buffer = address;
+		}
+		this.initCommands({
+			buffer,
+			byteOffset,
+		});
+	}
+
+	/**
+	 * Get address of Mach-O.
+	 *
+	 * @returns Pionter to Mach-O header.
+	 */
+	public address(): BufferPointer {
+		return this.header()!;
+	}
+}
diff --git a/macho/mod.ts b/macho/mod.ts
index 429bdbf..5e4f36e 100644
--- a/macho/mod.ts
+++ b/macho/mod.ts
@@ -1,4 +1,5 @@
 export * from './architecture.ts';
 export * from './macho.ts';
 export * from './machobase.ts';
+export * from './machoimage.ts';
 export * from './universal.ts';