From 7f5dd9aa80c4927694f92e6fea0ab1fdec5392d3 Mon Sep 17 00:00:00 2001
From: Dennis Ranke <dennis.ranke@gmail.com>
Date: Tue, 26 Oct 2021 21:02:57 +0200
Subject: [PATCH] some tidying up

---
 .gitignore              |  1 +
 Cargo.lock              |  7 +++++
 Cargo.toml              |  3 +-
 src/main.rs             | 69 +++++++++++++++++++++++++++++++----------
 test.hw => xorscroll.hw |  0
 5 files changed, 63 insertions(+), 17 deletions(-)
 rename test.hw => xorscroll.hw (100%)

diff --git a/.gitignore b/.gitignore
index ea8c4bf..d47b816 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /target
+*.uw8
diff --git a/Cargo.lock b/Cargo.lock
index dca4237..8886c5a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,10 +2,17 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "anyhow"
+version = "1.0.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61604a8f862e1d5c3229fdd78f8b02c68dcf73a4c4b05fd636d12240aaa242c1"
+
 [[package]]
 name = "hwas"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "nom",
  "wasm-encoder",
  "wasmparser",
diff --git a/Cargo.toml b/Cargo.toml
index e7ffaac..a922053 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,4 +8,5 @@ edition = "2021"
 [dependencies]
 nom = "7"
 wasmparser = "0.81"
-wasm-encoder = "0.8"
\ No newline at end of file
+wasm-encoder = "0.8"
+anyhow = "1"
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 4250b06..9f5bf75 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,24 +1,61 @@
-use std::fs::File;
+use anyhow::{anyhow, bail, Result};
 use std::io::prelude::*;
+use std::{fs::File, path::PathBuf};
 
-mod parser;
 mod ast;
-mod typecheck;
 mod constfold;
 mod emit;
+mod parser;
+mod typecheck;
 
+fn main() -> Result<()> {
+    let mut filename = PathBuf::from(
+        std::env::args()
+            .nth(1)
+            .ok_or_else(|| anyhow!("Path to .hw file missing"))?,
+    );
+    let mut input = String::new();
+    File::open(&filename)?.read_to_string(&mut input)?;
 
-fn main() {
-    let input = include_str!("../test.hw");
-    let result = parser::parse(input);
-    match result {
-        Ok(mut script) => {
-            constfold::fold_script(&mut script);
-            typecheck::tc_script(&mut script).unwrap();
-            let wasm = emit::emit(&script);
-            let mut file = File::create("test.wasm").unwrap();
-            file.write_all(&wasm).unwrap();
-        },
-        Err(err) => println!("error: {}", nom::error::convert_error(input, err))
-    }
+    let mut script = match parser::parse(input.as_str()) {
+        Ok(script) => script,
+        Err(err) => {
+            bail!(
+                "parse error: {}",
+                nom::error::convert_error(input.as_str(), err)
+            );
+        }
+    };
+
+    constfold::fold_script(&mut script);
+    typecheck::tc_script(&mut script).unwrap();
+    let wasm = emit::emit(&script);
+
+    wasmparser::validate(&wasm)?;
+
+    filename.set_extension("uw8");
+    File::create(filename)?.write_all(&wasm)?;
+
+    println!("Size of code section: {} bytes", code_section_size(&wasm)?);
+
+    Ok(())
+}
+
+fn code_section_size(wasm: &[u8]) -> Result<usize> {
+    for payload in wasmparser::Parser::new(0).parse_all(wasm) {
+        match payload? {
+            wasmparser::Payload::CodeSectionStart { range, .. } => {
+                let size = range.end - range.start;
+                let section_header_size = match size {
+                    0..=127 => 2,
+                    128..=16383 => 3,
+                    _ => 4,
+                };
+                return Ok(size + section_header_size);
+            }
+            _ => (),
+        }
+    }
+
+    bail!("No code section found");
 }
diff --git a/test.hw b/xorscroll.hw
similarity index 100%
rename from test.hw
rename to xorscroll.hw