Add optional --target flag

Author: davidlattimore

src/main.rs

@@ -35,7 +35,7 @@ use std::path::Path;
 use std::path::PathBuf;
 use symbol_graph::SymGraph;
 
-#[derive(Parser, Debug)]
+#[derive(Parser, Debug, Clone)]
 #[clap(version, about)]
 struct Args {
     /// Directory containing crate to analyze. Defaults to current working
@@ -82,6 +82,12 @@ struct Args {
     /// Don't print anything on success.
     #[clap(long)]
     quiet: bool,
+
+    /// Override the target used when compiling. e.g. specify "x86_64-apple-darwin" to compile for
+    /// x86 Mac. Note that build scripts and procedural macros will still be compiled for the host
+    /// target.
+    #[clap(long)]
+    target: Option<String>,
 }
 
 fn main() -> Result<()> {
@@ -105,14 +111,14 @@ fn run(args: Args) -> Result<()> {
         .canonicalize()
         .with_context(|| format!("Failed to read directory `{}`", root_path.display()))?;
 
-    proxy::clean(&root_path, args.colour)?;
+    proxy::clean(&root_path, &args)?;
 
     let config_path = args
         .cackle_path
         .clone()
         .unwrap_or_else(|| root_path.join("cackle.toml"));
 
-    let mut cackle = Cackle::new(config_path, &root_path, args)?;
+    let mut cackle = Cackle::new(config_path, &root_path, args.clone())?;
     cackle.load_config()?;
 
     if !cackle.args.object_paths.is_empty() {
@@ -124,7 +130,7 @@ fn run(args: Args) -> Result<()> {
     let mut problems = cackle.unfixed_problems(None)?;
     let config_path = cackle.flattened_config_path();
     let build_result = if problems.is_empty() {
-        proxy::invoke_cargo_build(&root_path, &config_path, cackle.args.colour, |request| {
+        proxy::invoke_cargo_build(&root_path, &config_path, &args, |request| {
             problems.merge(cackle.unfixed_problems(Some(request))?);
             Ok(problems.can_continue())
         })

src/proxy.rs

@@ -20,7 +20,7 @@
 //! * We can run them inside a sandbox if the config says to do so.
 //! * We can capture their output and check for any directives to cargo that haven't been permitted.
 
-use crate::colour::Colour;
+use crate::Args;
 use anyhow::Context;
 use anyhow::Result;
 use std::fmt::Display;
@@ -45,10 +45,10 @@ pub(crate) struct CargoBuildFailure {
     output: std::process::Output,
 }
 
-pub(crate) fn clean(dir: &Path, colour: Colour) -> Result<()> {
+pub(crate) fn clean(dir: &Path, args: &Args) -> Result<()> {
     // For now, we always clean before we build. It might be possible to not do this, but we'd need
     // to carefully track changes to things we care about, like cackle.toml.
-    run_command(&mut cargo::command("clean", dir, colour))?;
+    run_command(&mut cargo::command("clean", dir, args))?;
     Ok(())
 }
 
@@ -57,7 +57,7 @@ pub(crate) fn clean(dir: &Path, colour: Colour) -> Result<()> {
 pub(crate) fn invoke_cargo_build(
     dir: &Path,
     config_path: &Path,
-    colour: Colour,
+    args: &Args,
     mut callback: impl FnMut(rpc::Request) -> Result<rpc::CanContinueResponse>,
 ) -> Result<Option<CargoBuildFailure>> {
     if !std::env::var(SOCKET_ENV).unwrap_or_default().is_empty() {
@@ -72,7 +72,10 @@ pub(crate) fn invoke_cargo_build(
     let listener = UnixListener::bind(&ipc_path)
         .with_context(|| format!("Failed to create Unix socket `{}`", ipc_path.display()))?;
 
-    let mut command = cargo::command("build", dir, colour);
+    let mut command = cargo::command("build", dir, args);
+    if let Some(target) = &args.target {
+        command.arg("--target").arg(target);
+    }
     command
         .env(SOCKET_ENV, &ipc_path)
         .env(CONFIG_PATH_ENV, config_path)

src/proxy/cargo.rs

@@ -1,14 +1,14 @@
-use crate::colour::Colour;
+use crate::Args;
 use std::path::Path;
 use std::process::Command;
 
 /// The name of the cargo profile that we use.
 pub(crate) const PROFILE_NAME: &str = "cackle";
 
-pub(crate) fn command(base_command: &str, dir: &Path, colour: Colour) -> Command {
+pub(crate) fn command(base_command: &str, dir: &Path, args: &Args) -> Command {
     let mut command = Command::new("cargo");
     command.current_dir(dir);
-    if colour.should_use_colour() {
+    if args.colour.should_use_colour() {
         command.arg("--color=always");
     }
     command.arg(base_command);

test_crates/.cargo/config.toml

@@ -0,0 +1,7 @@
+# For instructions on how to set up cross compiling for Mac from Linux, see
+# https://wapl.es/rust/2019/02/17/rust-cross-compile-linux-to-macos.html
+
+[target.x86_64-apple-darwin]
+linker = "x86_64-apple-darwin14-clang"
+ar = "x86_64-apple-darwin14-ar"
+