feat(forge): add compiler subcommand

crates/forge/bin/cmd/compiler.rs

@@ -0,0 +1,54 @@
+use clap::{Parser, ValueHint};
+use eyre::Result;
+use foundry_compilers::Graph;
+use foundry_config::Config;
+use std::path::PathBuf;
+
+/// CLI arguments for `forge compiler`.
+#[derive(Clone, Debug, Parser)]
+pub enum CompilerSubcommands {
+    /// Retrieves the resolved version(s) of the compiler within the project.
+    #[command(visible_alias = "r")]
+    Resolve {
+        /// The root directory
+        #[arg(value_hint = ValueHint::DirPath, default_value = ".", value_name = "PATH")]
+        root: PathBuf,
+    },
+}
+
+impl CompilerSubcommands {
+    pub async fn run(self) -> Result<()> {
+        match &self {
+            Self::Resolve { root } => self.handle_version_resolving(root).await,
+        }
+    }
+
+    /// Retrieves the resolved version(s) of the compiler within the project.
+    async fn handle_version_resolving(&self, root: &PathBuf) -> Result<()> {
+        let config = Config::load_with_root(root);
+        let project = config.project()?;
+
+        let graph = Graph::resolve(&project.paths)?;
+        let (sources, _) = graph.into_sources_by_version(
+            project.offline,
+            &project.locked_versions,
+            &project.compiler,
+        )?;
+
+        for (language, sources) in sources {
+            for (version, sources) in sources {
+                println!("{language} {version}:");
+                for (idx, (path_file, _)) in sources.iter().enumerate() {
+                    let path = path_file
+                        .strip_prefix(&project.paths.root)
+                        .unwrap_or(path_file)
+                        .to_path_buf();
+                    let prefix = if idx == sources.len() - 1 { "└──" } else { "├──" };
+                    println!("{prefix} {}", path.display());
+                }
+            }
+        }
+
+        Ok(())
+    }
+}

crates/forge/bin/cmd/mod.rs

@@ -44,6 +44,7 @@ pub mod bind_json;
 pub mod build;
 pub mod cache;
 pub mod clone;
+pub mod compiler;
 pub mod config;
 pub mod coverage;
 pub mod create;

crates/forge/bin/main.rs

@@ -118,6 +118,7 @@ fn main() -> Result<()> {
         ForgeSubcommand::Generate(cmd) => match cmd.sub {
             GenerateSubcommands::Test(cmd) => cmd.run(),
         },
+        ForgeSubcommand::Compiler { command } => utils::block_on(command.run()),
         ForgeSubcommand::Soldeer(cmd) => utils::block_on(cmd.run()),
         ForgeSubcommand::Eip712(cmd) => cmd.run(),
         ForgeSubcommand::BindJson(cmd) => cmd.run(),

crates/forge/bin/opts.rs

@@ -1,8 +1,9 @@
 use crate::cmd::{
-    bind::BindArgs, bind_json, build::BuildArgs, cache::CacheArgs, clone::CloneArgs, config,
-    coverage, create::CreateArgs, debug::DebugArgs, doc::DocArgs, eip712, flatten, fmt::FmtArgs,
-    geiger, generate, init::InitArgs, inspect, install::InstallArgs, remappings::RemappingArgs,
-    remove::RemoveArgs, selectors::SelectorsSubcommands, snapshot, soldeer, test, tree, update,
+    bind::BindArgs, bind_json, build::BuildArgs, cache::CacheArgs, clone::CloneArgs,
+    compiler::CompilerSubcommands, config, coverage, create::CreateArgs, debug::DebugArgs,
+    doc::DocArgs, eip712, flatten, fmt::FmtArgs, geiger, generate, init::InitArgs, inspect,
+    install::InstallArgs, remappings::RemappingArgs, remove::RemoveArgs,
+    selectors::SelectorsSubcommands, snapshot, soldeer, test, tree, update,
 };
 use clap::{Parser, Subcommand, ValueHint};
 use forge_script::ScriptArgs;
@@ -162,6 +163,12 @@ pub enum ForgeSubcommand {
     /// Generate scaffold files.
     Generate(generate::GenerateArgs),
 
+    /// Compiler utilities
+    Compiler {
+        #[command(subcommand)]
+        command: CompilerSubcommands,
+    },
+
     /// Soldeer dependency manager.
     Soldeer(soldeer::SoldeerArgs),