Keep track of compiler info during build

rewatch/src/build.rs

@@ -1,6 +1,7 @@
 pub mod build_types;
 pub mod clean;
 pub mod compile;
+pub mod compiler_info;
 pub mod deps;
 pub mod logs;
 pub mod namespaces;
@@ -10,6 +11,7 @@ pub mod read_compile_state;
 
 use self::parse::parser_args;
 use crate::build::compile::{mark_modules_with_deleted_deps_dirty, mark_modules_with_expired_deps_dirty};
+use crate::build::compiler_info::{CompilerCheckResult, verify_compiler_info, write_compiler_info};
 use crate::helpers::emojis::*;
 use crate::helpers::{self};
 use crate::project_context::ProjectContext;
@@ -109,6 +111,20 @@ pub fn get_compiler_args(rescript_file_path: &Path) -> Result<String> {
  Ok(result)
 }
 
+pub fn get_compiler_info(project_context: &ProjectContext) -> Result<CompilerInfo> {
+ let bsc_path = helpers::get_bsc();
+ let bsc_hash = helpers::compute_file_hash(&bsc_path).ok_or(anyhow!(
+ "Failed to compute bsc hash for {}",
+ bsc_path.to_string_lossy()
+ ))?;
+ let runtime_path = compile::get_runtime_path(&project_context.current_config, project_context)?;
+ Ok(CompilerInfo {
+ bsc_path,
+ bsc_hash,
+ runtime_path,
+ })
+}
+
 pub fn initialize_build(
  default_timing: Option<Duration>,
  filter: &Option<regex::Regex>,
@@ -117,8 +133,8 @@ pub fn initialize_build(
  build_dev_deps: bool,
  snapshot_output: bool,
 ) -> Result<BuildState> {
- let bsc_path = helpers::get_bsc();
  let project_context = ProjectContext::new(path)?;
+ let compiler = get_compiler_info(&project_context)?;
 
  if !snapshot_output && show_progress {
  print!("{} {}Building package tree...", style("[1/7]").bold().dim(), TREE);
@@ -129,6 +145,8 @@ pub fn initialize_build(
  let packages = packages::make(filter, &project_context, show_progress, build_dev_deps)?;
  let timing_package_tree_elapsed = timing_package_tree.elapsed();
 
+ let compiler_check = verify_compiler_info(&packages, &compiler);
+
  if !snapshot_output && show_progress {
  println!(
  "{}{} {}Built package tree in {:.2}s",
@@ -139,6 +157,14 @@ pub fn initialize_build(
  .unwrap_or(timing_package_tree_elapsed)
  .as_secs_f64()
  );
+ if let CompilerCheckResult::CleanedPackagesDueToCompiler = compiler_check {
+ println!(
+ "{}{} {}Cleaned previous build due to compiler update",
+ LINE_CLEAR,
+ style("[1/7]").bold().dim(),
+ SWEEP
+ );
+ }
  }
 
  if !packages::validate_packages_dependencies(&packages) {
@@ -156,7 +182,7 @@ pub fn initialize_build(
  let _ = stdout().flush();
  }
 
- let mut build_state = BuildState::new(project_context, packages, bsc_path);
+ let mut build_state = BuildState::new(project_context, packages, compiler);
  packages::parse_packages(&mut build_state);
  let timing_source_files_elapsed = timing_source_files.elapsed();
 
@@ -448,6 +474,9 @@ pub fn incremental_build(
  log_deprecations(build_state);
  }
 
+ // Write per-package compiler metadata to `lib/bs/compiler-info.json` (idempotent)
+ write_compiler_info(build_state);
+
  Ok(())
  }
 }

rewatch/src/build/build_types.rs

@@ -2,6 +2,7 @@ use crate::build::packages::{Namespace, Package};
 use crate::config::Config;
 use crate::project_context::ProjectContext;
 use ahash::{AHashMap, AHashSet};
+use blake3::Hash;
 use std::{fmt::Display, path::PathBuf, time::SystemTime};
 
 #[derive(Debug, Clone, PartialEq)]
@@ -96,10 +97,17 @@ pub struct BuildState {
  pub packages: AHashMap<String, Package>,
  pub module_names: AHashSet<String>,
  pub deleted_modules: AHashSet<String>,
- pub bsc_path: PathBuf,
+ pub compiler_info: CompilerInfo,
  pub deps_initialized: bool,
 }
 
+#[derive(Debug, Clone)]
+pub struct CompilerInfo {
+ pub bsc_path: PathBuf,
+ pub bsc_hash: Hash,
+ pub runtime_path: PathBuf,
+}
+
 impl BuildState {
  pub fn get_package(&self, package_name: &str) -> Option<&Package> {
  self.packages.get(package_name)
@@ -111,15 +119,15 @@ impl BuildState {
  pub fn new(
  project_context: ProjectContext,
  packages: AHashMap<String, Package>,
- bsc_path: PathBuf,
+ compiler: CompilerInfo,
  ) -> Self {
  Self {
  project_context,
  module_names: AHashSet::new(),
  modules: AHashMap::new(),
  packages,
  deleted_modules: AHashSet::new(),
- bsc_path,
+ compiler_info: compiler,
  deps_initialized: false,
  }
  }

rewatch/src/build/clean.rs

@@ -1,5 +1,6 @@
 use super::build_types::*;
 use super::packages;
+use crate::build;
 use crate::build::packages::Package;
 use crate::config::Config;
 use crate::helpers;
@@ -332,9 +333,8 @@ pub fn cleanup_after_build(build_state: &BuildState) {
 
 pub fn clean(path: &Path, show_progress: bool, snapshot_output: bool, clean_dev_deps: bool) -> Result<()> {
  let project_context = ProjectContext::new(path)?;
-
+ let compiler_info = build::get_compiler_info(&project_context)?;
  let packages = packages::make(&None, &project_context, show_progress, clean_dev_deps)?;
- let bsc_path = helpers::get_bsc();
 
  let timing_clean_compiler_assets = Instant::now();
  if !snapshot_output && show_progress {
@@ -364,7 +364,7 @@ pub fn clean(path: &Path, show_progress: bool, snapshot_output: bool, clean_dev_
  }
 
  let timing_clean_mjs = Instant::now();
- let mut build_state = BuildState::new(project_context, packages, bsc_path);
+ let mut build_state = BuildState::new(project_context, packages, compiler_info);
  packages::parse_packages(&mut build_state);
  let root_config = build_state.get_root_config();
  let suffix_for_print = if snapshot_output || !show_progress {
@@ -418,7 +418,7 @@ pub fn clean(path: &Path, show_progress: bool, snapshot_output: bool, clean_dev_
  Ok(())
 }
 
-fn clean_package(show_progress: bool, snapshot_output: bool, package: &Package) {
+pub fn clean_package(show_progress: bool, snapshot_output: bool, package: &Package) {
  if show_progress {
  if snapshot_output {
  println!("Cleaning {}", package.name)
@@ -441,4 +441,7 @@ fn clean_package(show_progress: bool, snapshot_output: bool, package: &Package)
  let path_str = package.get_ocaml_build_path();
  let path = std::path::Path::new(&path_str);
  let _ = std::fs::remove_dir_all(path);
+
+ // remove the per-package compiler metadata file so that a subsequent build writes fresh metadata
+ let _ = std::fs::remove_file(package.get_compiler_info_path());
 }

rewatch/src/build/compile.rs

@@ -16,7 +16,9 @@ use console::style;
 use log::{debug, trace};
 use rayon::prelude::*;
 use std::path::Path;
+use std::path::PathBuf;
 use std::process::Command;
+use std::sync::OnceLock;
 use std::time::SystemTime;
 
 pub fn compile(
@@ -336,22 +338,36 @@ pub fn compile(
  Ok((compile_errors, compile_warnings, num_compiled_modules))
 }
 
-pub fn get_runtime_path_args(
- package_config: &Config,
- project_context: &ProjectContext,
-) -> Result<Vec<String>> {
- match std::env::var("RESCRIPT_RUNTIME") {
- Ok(runtime_path) => Ok(vec!["-runtime-path".to_string(), runtime_path]),
+static RUNTIME_PATH_MEMO: OnceLock<PathBuf> = OnceLock::new();
+
+pub fn get_runtime_path(package_config: &Config, project_context: &ProjectContext) -> Result<PathBuf> {
+ if let Some(p) = RUNTIME_PATH_MEMO.get() {
+ return Ok(p.clone());
+ }
+
+ let resolved = match std::env::var("RESCRIPT_RUNTIME") {
+ Ok(runtime_path) => Ok(PathBuf::from(runtime_path)),
  Err(_) => match helpers::try_package_path(package_config, project_context, "@rescript/runtime") {
- Ok(runtime_path) => Ok(vec![
- "-runtime-path".to_string(),
- runtime_path.to_string_lossy().to_string(),
- ]),
+ Ok(runtime_path) => Ok(runtime_path),
  Err(err) => Err(anyhow!(
  "The rescript runtime package could not be found.\nPlease set RESCRIPT_RUNTIME environment variable or make sure the runtime package is installed.\nError: {err}"
  )),
  },
- }
+ }?;
+
+ let _ = RUNTIME_PATH_MEMO.set(resolved.clone());
+ Ok(resolved)
+}
+
+pub fn get_runtime_path_args(
+ package_config: &Config,
+ project_context: &ProjectContext,
+) -> Result<Vec<String>> {
+ let runtime_path = get_runtime_path(package_config, project_context)?;
+ Ok(vec![
+ "-runtime-path".to_string(),
+ runtime_path.to_string_lossy().to_string(),
+ ])
 }
 
 pub fn compiler_args(
@@ -581,7 +597,7 @@ fn compile_file(
  let BuildState {
  packages,
  project_context,
- bsc_path,
+ compiler_info,
  ..
  } = build_state;
  let root_config = build_state.get_root_config();
@@ -612,7 +628,7 @@ fn compile_file(
  package.is_local_dep,
  )?;
 
- let to_mjs = Command::new(bsc_path)
+ let to_mjs = Command::new(&compiler_info.bsc_path)
  .current_dir(
  build_path_abs
  .canonicalize()
@@ -748,6 +764,9 @@ fn compile_file(
  }
  });
 
+ // TODO: Optionally record per-module successful compile timestamps if needed
+ // for future metadata-based invalidation. Current metadata is per-package.
+
  if helpers::contains_ascii_characters(&err) {
  if package.is_local_dep {
  // suppress warnings of external deps