feat(dtmt): Improve error messages when compiling Lua

Fixes #58.

crates/dtmm/src/controller/game.rs

@@ -1,4 +1,3 @@
-use std::ffi::CString;
 use std::io::{Cursor, ErrorKind};
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
@@ -216,7 +215,6 @@ async fn build_bundles(state: Arc<ActionState>) -> Result<Vec<Bundle>> {
         let _enter = span.enter();
 
         let lua = build_mod_data_lua(state.clone());
-        let lua = CString::new(lua).wrap_err("Failed to build CString from mod data Lua string")?;
         let file =
             lua::compile(MOD_DATA_SCRIPT, &lua).wrap_err("Failed to compile mod data Lua file")?;
 
@@ -437,9 +435,8 @@ async fn patch_boot_bundle(state: Arc<ActionState>) -> Result<Vec<Bundle>> {
         let _enter = span.enter();
 
         let lua = include_str!("../../assets/mod_main.lua");
-        let lua = CString::new(lua).wrap_err("Failed to build CString from mod main Lua string")?;
         let file =
-            lua::compile(MOD_BOOT_SCRIPT, &lua).wrap_err("Failed to compile mod main Lua file")?;
+            lua::compile(MOD_BOOT_SCRIPT, lua).wrap_err("Failed to compile mod main Lua file")?;
 
         boot_bundle.add_file(file);
     }

crates/dtmt/src/cmd/build.rs

@@ -151,17 +151,6 @@ where
     results.into_iter().collect()
 }
 
-#[tracing::instrument(skip_all, fields(files = files.len()))]
-fn compile_bundle(name: String, files: Vec<BundleFile>) -> Result<Bundle> {
-    let mut bundle = Bundle::new(name);
-
-    for file in files {
-        bundle.add_file(file);
-    }
-
-    Ok(bundle)
-}
-
 #[tracing::instrument]
 async fn build_package<P1, P2>(package: P1, root: P2) -> Result<Bundle>
 where
@@ -182,18 +171,20 @@ where
         .await
         .wrap_err_with(|| format!("Invalid package file {}", &pkg_name))?;
 
-    compile_package_files(&pkg, root)
-        .await
-        .wrap_err("Failed to compile package")
-        .and_then(|files| compile_bundle(pkg_name, files))
-        .wrap_err("Failed to build bundle")
+    let files = compile_package_files(&pkg, root).await?;
+    let mut bundle = Bundle::new(pkg_name);
+    for file in files {
+        bundle.add_file(file);
+    }
+
+    Ok(bundle)
 }
 
 fn normalize_file_path<P: AsRef<Path>>(path: P) -> Result<PathBuf> {
     let path = path.as_ref();
 
     if path.is_absolute() || path.has_root() {
-        let err = eyre::eyre!("path is absolute: {}", path.display());
+        let err = eyre::eyre!("Path is absolute: {}", path.display());
         return Err(err).with_suggestion(|| "Specify a relative file path.".to_string());
     }
 
@@ -302,7 +293,7 @@ pub(crate) async fn run(_ctx: sdk::Context, matches: &ArgMatches) -> Result<()>
 
             let bundle = build_package(path, &cfg.dir).await.wrap_err_with(|| {
                 format!(
-                    "failed to build package {} in {}",
+                    "Failed to build package '{}' at '{}'",
                     path.display(),
                     cfg.dir.display()
                 )

lib/sdk/src/bundle/file.rs

@@ -1,4 +1,3 @@
-use std::ffi::CString;
 use std::io::{Cursor, Read, Seek, Write};
 use std::path::Path;
 
@@ -660,11 +659,8 @@ impl BundleFile {
         S: AsRef<str>,
     {
         match file_type {
-            BundleFileType::Lua => {
-                let sjson =
-                    CString::new(sjson.as_ref()).wrap_err("Failed to build CString from SJSON")?;
-                lua::compile(name, sjson)
-            }
+            BundleFileType::Lua => lua::compile(name.clone(), sjson)
+                .wrap_err_with(|| format!("Failed to compile Lua file '{}'", name)),
             BundleFileType::Unknown(_) => {
                 eyre::bail!("Unknown file type. Cannot compile from SJSON");
             }

lib/sdk/src/filetype/lua.rs

@@ -25,7 +25,7 @@ where
 pub fn compile<S, C>(name: S, code: C) -> Result<BundleFile>
 where
     S: Into<String>,
-    C: AsRef<CStr>,
+    C: AsRef<str>,
 {
     let name = name.into();
     let code = code.as_ref();
@@ -34,15 +34,33 @@ where
         let state = lua::luaL_newstate();
         lua::luaL_openlibs(state);
 
-        lua::lua_pushstring(state, code.as_ptr() as _);
-        lua::lua_setglobal(state, b"code\0".as_ptr() as _);
-
         let name = CString::new(name.as_bytes())
             .wrap_err_with(|| format!("Cannot convert name into CString: {}", name))?;
-        lua::lua_pushstring(state, name.as_ptr() as _);
-        lua::lua_setglobal(state, b"name\0".as_ptr() as _);
+        match lua::luaL_loadbuffer(
+            state,
+            code.as_ptr() as _,
+            code.len() as _,
+            name.as_ptr() as _,
+        ) as u32
+        {
+            lua::LUA_OK => {}
+            lua::LUA_ERRSYNTAX => {
+                let err = lua::lua_tostring(state, -1);
+                let err = CStr::from_ptr(err).to_string_lossy().to_string();
 
-        let run = b"return string.dump(loadstring(code, \"@\" .. name), false)\0";
+                lua::lua_close(state);
+
+                eyre::bail!("Invalid syntax: {}", err);
+            }
+            lua::LUA_ERRMEM => {
+                lua::lua_close(state);
+                eyre::bail!("Failed to allocate sufficient memory to compile LuaJIT bytecode")
+            }
+            _ => unreachable!(),
+        }
+        lua::lua_setglobal(state, b"fn\0".as_ptr() as _);
+
+        let run = b"return string.dump(fn, false)\0";
         match lua::luaL_loadstring(state, run.as_ptr() as _) as u32 {
             lua::LUA_OK => {}
             lua::LUA_ERRSYNTAX => {