idl: Remove `anchor-syn` dependency (#3030)

CHANGELOG.md

@@ -27,6 +27,7 @@ The minor version will be incremented upon a breaking change and the patch versi
 - cli: Add `idl type` command ([#3017](https://github.com/coral-xyz/anchor/pull/3017)).
 - lang: Add `anchor_lang::pubkey` macro for declaring `Pubkey` const values ([#3021](https://github.com/coral-xyz/anchor/pull/3021)).
 - cli: Sync program ids on the initial build ([#3023](https://github.com/coral-xyz/anchor/pull/3023)).
+- idl: Remove `anchor-syn` dependency ([#3030](https://github.com/coral-xyz/anchor/pull/3030)).
 
 ### Fixes
 

Cargo.lock

@@ -291,7 +291,6 @@ dependencies = [
 name = "anchor-lang-idl"
 version = "0.1.0"
 dependencies = [
- "anchor-syn",
  "anyhow",
  "heck 0.3.3",
  "regex",

idl/Cargo.toml

@@ -12,7 +12,7 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [features]
-build = ["anchor-syn", "regex"]
+build = ["regex"]
 convert = ["heck", "sha2"]
 
 [dependencies]
@@ -21,7 +21,6 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 
 # `build` feature only
-anchor-syn = { path = "../lang/syn", version = "0.30.0", optional = true }
 regex = { version = "1", optional = true }
 
 # `convert` feature only

idl/src/build.rs

@@ -5,7 +5,6 @@ use std::{
     process::{Command, Stdio},
 };
 
-use anchor_syn::parser::context::CrateContext;
 use anyhow::{anyhow, Result};
 use regex::Regex;
 use serde::Deserialize;
@@ -51,15 +50,7 @@ pub fn build_idl(
     skip_lint: bool,
     no_docs: bool,
 ) -> Result<Idl> {
-    // Check safety comments
-    let program_path = program_path.as_ref();
-    let lib_path = program_path.join("src").join("lib.rs");
-    let ctx = CrateContext::parse(lib_path)?;
-    if !skip_lint {
-        ctx.safety_checks()?;
-    }
-
-    let idl = build(program_path, resolution, no_docs)?;
+    let idl = build(program_path.as_ref(), resolution, skip_lint, no_docs)?;
     let idl = convert_module_paths(idl);
     let idl = sort(idl);
     verify(&idl)?;
@@ -68,7 +59,7 @@ pub fn build_idl(
 }
 
 /// Build IDL.
-fn build(program_path: &Path, resolution: bool, no_docs: bool) -> Result<Idl> {
+fn build(program_path: &Path, resolution: bool, skip_lint: bool, no_docs: bool) -> Result<Idl> {
     // `nightly` toolchain is currently required for building the IDL.
     let toolchain = std::env::var("RUSTUP_TOOLCHAIN")
         .map(|toolchain| format!("+{}", toolchain))
@@ -95,6 +86,10 @@ fn build(program_path: &Path, resolution: bool, no_docs: bool) -> Result<Idl> {
             "ANCHOR_IDL_BUILD_RESOLUTION",
             if resolution { "TRUE" } else { "FALSE" },
         )
+        .env(
+            "ANCHOR_IDL_BUILD_SKIP_LINT",
+            if skip_lint { "TRUE" } else { "FALSE" },
+        )
         .env("ANCHOR_IDL_BUILD_PROGRAM_PATH", program_path)
         .env("RUSTFLAGS", "--cfg procmacro2_semver_exempt")
         .current_dir(program_path)

lang/syn/src/idl/program.rs

@@ -1,4 +1,6 @@
-use anyhow::Result;
+use std::path::PathBuf;
+
+use anyhow::{anyhow, Result};
 use heck::CamelCase;
 use proc_macro2::TokenStream;
 use quote::{format_ident, quote};
@@ -7,10 +9,15 @@ use super::{
     common::{gen_print_section, get_idl_module_path, get_no_docs},
     defined::gen_idl_type,
 };
-use crate::{parser::docs, Program};
+use crate::{
+    parser::{context::CrateContext, docs},
+    Program,
+};
 
 /// Generate the IDL build print function for the program module.
 pub fn gen_idl_print_fn_program(program: &Program) -> TokenStream {
+    check_safety_comments().unwrap_or_else(|e| panic!("Safety checks failed: {e}"));
+
     let idl = get_idl_module_path();
     let no_docs = get_no_docs();
 
@@ -139,3 +146,21 @@ pub fn gen_idl_print_fn_program(program: &Program) -> TokenStream {
         }
     }
 }
+
+/// Check safety comments.
+fn check_safety_comments() -> Result<()> {
+    let skip_lint = option_env!("ANCHOR_IDL_BUILD_SKIP_LINT")
+        .map(|val| val == "TRUE")
+        .unwrap_or_default();
+    if skip_lint {
+        return Ok(());
+    }
+
+    std::env::var("ANCHOR_IDL_BUILD_PROGRAM_PATH")
+        .map(PathBuf::from)
+        .map(|path| path.join("src").join("lib.rs"))
+        .map_err(|_| anyhow!("Failed to get program path"))
+        .map(CrateContext::parse)?
+        .map_err(|e| anyhow!("Failed to parse crate: {e}"))?
+        .safety_checks()
+}