From c710e1b893f16b684d2ec8774267f7250c1c039c Mon Sep 17 00:00:00 2001
From: Cassie Jones <code@witchoflight.com>
Date: Mon, 13 Jan 2020 10:41:47 -0500
Subject: [PATCH] Add disassembler, update spec

---
 isa.txt                           |  3 +--
 toolchain/src/bin/disassembler.rs | 14 ++++++++++++++
 toolchain/src/lib.rs              | 15 +++++++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)
 create mode 100644 toolchain/src/bin/disassembler.rs

diff --git a/isa.txt b/isa.txt
index 041ecb7..ac9e4ca 100644
--- a/isa.txt
+++ b/isa.txt
@@ -42,8 +42,7 @@ Special registers: pc, it (accumulator), data1 (segment), data2 (segment), code
 
 1111_00oo iiiiiiii ALUI it <- it {andi, iori, xori, (see below)} i
      0011 0iiiiiii ALUI it <- it + i (ADDI)
-     0011 100ooiii ALUI it <- it {roli, lsli, lsri, asri} i
-     0011 101xxxxx      (probably permanently unused, but you could cram in more small ALU ops?)
+     0011 10oooiii ALUI it <- it {roli, lsli, lsri, asri, clri, seti, togi, exti} i
      0011 11iiiiii ALUI it <- it + (whole field, thus allowing many negative numbers) (ADDI)
      0100 iiiiiiii BEZI branch ±i if it == 0
      0101 iiiiiiii      (reserved branch; SUB2, BLTI is no faster than ISLT, BEZI)
diff --git a/toolchain/src/bin/disassembler.rs b/toolchain/src/bin/disassembler.rs
new file mode 100644
index 0000000..b7d729e
--- /dev/null
+++ b/toolchain/src/bin/disassembler.rs
@@ -0,0 +1,14 @@
+use std::io;
+use toolchain::{inst::decode::Decode, Inst};
+
+fn main() {
+    let stdin = io::stdin();
+    let mut input = stdin.lock();
+    loop {
+        match Inst::decode(&mut input) {
+            Ok(inst) => println!("{}", inst),
+            Err(err) if err.kind() == io::ErrorKind::UnexpectedEof => break,
+            Err(err) => println!("Error: {}", err),
+        }
+    }
+}
diff --git a/toolchain/src/lib.rs b/toolchain/src/lib.rs
index d4cc11e..67c875f 100644
--- a/toolchain/src/lib.rs
+++ b/toolchain/src/lib.rs
@@ -1 +1,16 @@
 pub mod inst;
+
+pub use inst::{decode::Decode, Inst};
+use std::io;
+
+pub fn disassemble(reader: &mut impl io::Read) -> io::Result<Vec<Inst>> {
+    let mut results = Vec::new();
+    loop {
+        match Inst::decode(reader) {
+            Ok(inst) => results.push(inst),
+            Err(err) if err.kind() == io::ErrorKind::UnexpectedEof => break,
+            Err(err) => return Err(err),
+        }
+    }
+    Ok(results)
+}
-- 
2.47.0