From 3ec1a8efdaba91673a8e20c3e9a18033cfe0505e Mon Sep 17 00:00:00 2001
From: Steve Biedermann <steve.biedermann@matrix42.com>
Date: Thu, 12 Dec 2024 15:57:00 +0100
Subject: [PATCH] better cli

---
 src/main.rs   | 175 ++++++++++++++++++++++++++++++--------------------
 src/native.rs |   4 +-
 2 files changed, 107 insertions(+), 72 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index fdacc9c..058d536 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,7 +1,7 @@
-use std::path::PathBuf;
+use std::{io::BufWriter, path::PathBuf};
 
-use byteorder::ReadBytesExt;
-use clap::Parser;
+use byteorder::{ReadBytesExt, WriteBytesExt};
+use clap::{Parser, Subcommand};
 use common::{CpuTrait, RunMode};
 use native::{Bytecode, NativeCpu};
 use std::io::BufReader;
@@ -10,86 +10,121 @@ mod native;
 
 #[derive(Parser)]
 struct Args {
-    memory: Option<PathBuf>,
-    #[arg(short, long)]
+    #[arg(short, long, global = true)]
     verbose: bool,
+    #[command(subcommand)]
+    action: Action,
 }
 
-fn main() -> anyhow::Result<()> {
-    let Args { memory, verbose } = Args::parse();
+#[derive(Subcommand)]
+enum Action {
+    Run { path: PathBuf },
+    RunDemo,
+    WriteDemo { path: PathBuf },
+}
 
-    let memory = memory
-        .and_then(|p| {
-            std::fs::File::open(p)
-                .and_then(|file| {
+const DEMO: &[u32] = {
+    use Bytecode::*;
+    &[
+        /* 0 */ PushValue as u32,
+        /* 1 */ 42,
+        /* 2 */ LoadValue as u32,
+        /* 3 */ 0,
+        /* 4 */ 10,
+        /* 5 */ PushReg as u32,
+        /* 6 */ 0,
+        /* 7 */ Call as u32,
+        /* 8 */ 17,
+        /* 9 */ Pop as u32,
+        /* 10 */ 3,
+        /* 11 */ Store as u32,
+        /* 12 */ 40,
+        /* 13 */ 3,
+        /* 14 */ Inspect as u32,
+        /* 15 */ 40,
+        /* 16 */ Halt as u32,
+        /* 17 */ Pop as u32,
+        /* 18 */ 5,
+        /* 19 */ Pop as u32,
+        /* 20 */ 0,
+        /* 21 */ Pop as u32,
+        /* 22 */ 1,
+        /* 23 */ Add as u32,
+        /* 24 */ 0,
+        /* 25 */ 1,
+        /* 26 */ PushReg as u32,
+        /* 27 */ 5,
+        /* 28 */ RetReg as u32,
+        /* 29 */ 0,
+    ]
+};
+
+fn main() -> anyhow::Result<()> {
+    let Args { action, verbose } = Args::parse();
+
+    match action {
+        Action::RunDemo => {
+            let mut cpu = NativeCpu::new(1024 * 1024, 6);
+            cpu.set_verbose(verbose);
+
+            cpu.load_memory(0, DEMO);
+
+            let stats = cpu.execute(RunMode::Run)?;
+
+            println!();
+            println!(" ========== STATS ===========");
+            println!();
+
+            if verbose {
+                println!(
+                    "Total cycles: {}, Memory Access score: {}",
+                    stats.cycles, stats.memory_access_score
+                );
+            }
+
+            println!("Total Score: {}", stats.cycles + stats.memory_access_score);
+        }
+        Action::WriteDemo { path } => {
+            let file = std::fs::File::create(path)?;
+            let mut writer = BufWriter::new(file);
+            for &v in DEMO {
+                writer.write_u32::<byteorder::LittleEndian>(v)?;
+            }
+        }
+
+        Action::Run { path } => {
+            let memory = std::fs::File::open(path)
+                .map(|file| {
                     let mut reader = BufReader::new(file);
                     let mut values = Vec::new();
-                    let result = reader.read_u32_into::<byteorder::LittleEndian>(&mut values);
-                    result.map(|_| values)
+                    while let Ok(v) = reader.read_u32::<byteorder::LittleEndian>() {
+                        values.push(v);
+                    }
+                    values
                 })
-                .ok()
-        })
-        .unwrap_or_else(|| {
-            use Bytecode::*;
-            vec![
-                /* 0 */ Jmp as u32,
-                /* 1 */ 15,
-                /* 2 */ Pop as u32,
-                /* 3 */ 5,
-                /* 4 */ Pop as u32,
-                /* 5 */ 0,
-                /* 6 */ Pop as u32,
-                /* 7 */ 1,
-                /* 8 */ Add as u32,
-                /* 9 */ 0,
-                /* 10 */ 1,
-                /* 11 */ PushReg as u32,
-                /* 12 */ 5,
-                /* 13 */ RetReg as u32,
-                /* 14 */ 0,
-                /* 15 */ Nop as u32,
-                /* 16 */ Nop as u32,
-                /* 17 */ Nop as u32,
-                /* 18 */ Nop as u32,
-                /* 19 */ PushValue as u32,
-                /* 20 */ 42,
-                /* 21 */ LoadValue as u32,
-                /* 22 */ 0,
-                /* 23 */ 10,
-                /* 24 */ PushReg as u32,
-                /* 25 */ 0,
-                /* 26 */ Call as u32,
-                /* 27 */ 2,
-                /* 28 */ Pop as u32,
-                /* 29 */ 3,
-                /* 30 */ Store as u32,
-                /* 31 */ 40,
-                /* 32 */ 3,
-                /* 33 */ Inspect as u32,
-                /* 34 */ 40,
-                /* 35 */ Halt as u32,
-            ]
-        });
+                .unwrap();
 
-    let mut cpu = NativeCpu::new(1024 * 1024, 6);
-    cpu.set_verbose(verbose);
+            let mut cpu = NativeCpu::new(1024 * 1024, 6);
+            cpu.set_verbose(verbose);
 
-    cpu.load_memory(0, &memory);
+            cpu.load_memory(0, &memory);
 
-    let stats = cpu.execute(RunMode::Run)?;
+            let stats = cpu.execute(RunMode::Run)?;
 
-    println!();
-    println!(" ========== STATS ===========");
-    println!();
+            println!();
+            println!(" ========== STATS ===========");
+            println!();
 
-    if verbose {
-        println!(
-            "Total cycles: {}, Memory Access score: {}",
-            stats.cycles, stats.memory_access_score
-        );
+            if verbose {
+                println!(
+                    "Total cycles: {}, Memory Access score: {}",
+                    stats.cycles, stats.memory_access_score
+                );
+            }
+
+            println!("Total Score: {}", stats.cycles + stats.memory_access_score);
+        }
     }
 
-    println!("Total Score: {}", stats.cycles + stats.memory_access_score);
-
     Ok(())
 }
diff --git a/src/native.rs b/src/native.rs
index 086f20d..fde2039 100644
--- a/src/native.rs
+++ b/src/native.rs
@@ -214,12 +214,12 @@ impl NativeCpu {
                     let reg = self.read_memory(self.instruction_pointer)?;
                     self.instruction_pointer += 1;
 
-                    let val = self.registers[reg as usize];
-
                     if self.verbose {
                         println!("PUSH R{}", reg);
                     }
 
+                    let val = self.registers[reg as usize];
+
                     self.push_stack(val)?;
 
                     self.cycles += 2;