From 8e90799e2791a322f6df5c435280433e2c381773 Mon Sep 17 00:00:00 2001
From: Antonin Delpeuch <antonin@delpeuch.eu>
Date: Thu, 17 Jul 2025 15:48:26 +0200
Subject: [PATCH] =?UTF-8?q?feat(generate):=C2=A0Support=20for=20--stage=3D?=
 =?UTF-8?q?json/parser/lib?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 crates/cli/src/main.rs          | 31 ++++++++++++++++++++++++-------
 crates/generate/src/generate.rs | 11 ++++++-----
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/crates/cli/src/main.rs b/crates/cli/src/main.rs
index 60314d28..cb849f09 100644
--- a/crates/cli/src/main.rs
+++ b/crates/cli/src/main.rs
@@ -85,6 +85,17 @@ struct Init {
     pub grammar_path: Option<PathBuf>,
 }
 
+#[derive(Clone, Debug, Default, ValueEnum, PartialEq, Eq)]
+enum GenerationStage {
+    /// Generate `grammar.json` and `node-types.json`
+    Json,
+    /// Generate `parser.c` and related files
+    #[default]
+    Parser,
+    /// Compile to a library
+    Lib,
+}
+
 #[derive(Args)]
 #[command(alias = "gen", alias = "g")]
 struct Generate {
@@ -107,8 +118,12 @@ struct Generate {
                 )
     )]
     pub abi_version: Option<String>,
-    /// Compile all defined languages in the current dir
-    #[arg(long, short = 'b')]
+    /// Which generation stage to end after
+    #[arg(long)]
+    #[clap(value_enum, default_value_t=GenerationStage::Parser)]
+    pub stage: GenerationStage,
+    /// Deprecated: use --stage=lib.
+    #[arg(long, short = 'b', conflicts_with = "stage")]
     pub build: bool,
     /// Compile a parser in debug mode
     #[arg(long, short = '0')]
@@ -133,9 +148,6 @@ struct Generate {
         default_value = "node"
     )]
     pub js_runtime: Option<String>,
-    /// Only generate `grammar.json` by evaluating `grammar.js`, but do not generate `parser.c` and related files afterwards
-    #[arg(long)]
-    pub evaluate_only: bool,
 }
 
 #[derive(Args)]
@@ -803,6 +815,11 @@ impl Generate {
                         version.parse().expect("invalid abi version flag")
                     }
                 });
+        if self.build {
+            // TODO: remove the `--build` argument in 0.27
+            // TODO: migrate to `warn!` once https://github.com/tree-sitter/tree-sitter/pull/4604 is merged
+            eprintln!("Warning: --build is deprecated, use --stage=lib instead");
+        }
         if let Err(err) = tree_sitter_generate::generate_parser_in_directory(
             current_dir,
             self.output.as_deref(),
@@ -810,7 +827,7 @@ impl Generate {
             abi_version,
             self.report_states_for_rule.as_deref(),
             self.js_runtime.as_deref(),
-            self.evaluate_only,
+            self.stage != GenerationStage::Json,
         ) {
             if self.json {
                 eprintln!("{}", serde_json::to_string_pretty(&err)?);
@@ -821,7 +838,7 @@ impl Generate {
                 Err(anyhow!(err.to_string())).with_context(|| "Error when generating parser")?;
             }
         }
-        if self.build {
+        if self.stage == GenerationStage::Lib || self.build {
             if let Some(path) = self.libdir {
                 loader = loader::Loader::with_parser_lib_path(path);
             }
diff --git a/crates/generate/src/generate.rs b/crates/generate/src/generate.rs
index e954ffc0..ffc71587 100644
--- a/crates/generate/src/generate.rs
+++ b/crates/generate/src/generate.rs
@@ -196,9 +196,8 @@ where
     let src_path = out_path.map_or_else(|| repo_path.join("src"), |p| p.into());
     let header_path = src_path.join("tree_sitter");
 
-    // Ensure that the output directories exist.
+    // Ensure that the output directory exists
     fs::create_dir_all(&src_path)?;
-    fs::create_dir_all(&header_path)?;
 
     if grammar_path.file_name().unwrap() != "grammar.json" {
         fs::write(src_path.join("grammar.json"), &grammar_json).map_err(|e| {
@@ -210,13 +209,14 @@ where
     }
 
     // If our job is only to generate `grammar.json` and not `parser.c`, stop here.
+    let input_grammar = parse_grammar(&grammar_json)?;
+
     if !generate_parser {
+        let node_types_json = generate_node_types_from_grammar(&input_grammar)?.node_types_json;
+        write_file(&src_path.join("node-types.json"), node_types_json)?;
         return Ok(());
     }
 
-    // Parse and preprocess the grammar.
-    let input_grammar = parse_grammar(&grammar_json)?;
-
     let semantic_version = read_grammar_version(&repo_path)?;
 
     if semantic_version.is_none() && abi_version > ABI_VERSION_MIN {
@@ -238,6 +238,7 @@ where
 
     write_file(&src_path.join("parser.c"), c_code)?;
     write_file(&src_path.join("node-types.json"), node_types_json)?;
+    fs::create_dir_all(&header_path)?;
     write_file(&header_path.join("alloc.h"), ALLOC_HEADER)?;
     write_file(&header_path.join("array.h"), ARRAY_HEADER)?;
     write_file(&header_path.join("parser.h"), tree_sitter::PARSER_HEADER)?;