feat: new arg --cargo-config for passing --config to cargo

This is another step toward making opt-dist work in sandboxed environments.

`--cargo-config` is added to the following subcommands:

* `binary_stats compile`
* `bench_runtime_local`
* `bench_local`
* `profile_local`

The current rustc-perf uses `tempfile::Tempdir` as the working
directory when collecting profiles from some of these packages.
This "tmp" working directory usage make it impossible for Cargo to pick
up the correct vendor sources setting in `.cargo/config.toml` bundled
in the rustc-src tarball.

We can leverage [`cargo --config`][1] to specify additional Cargo's
configuration. Training data then could build with correct vendored
settings via the `--cargo-config` flag.

[1]: https://doc.rust-lang.org/nightly/cargo/commands/cargo.html#option-cargo---config

collector/src/artifact_stats.rs

@@ -164,6 +164,9 @@ pub fn compile_and_get_stats(
 
     let mut cmd = Command::new(&toolchain.components.cargo);
     cmd.arg("build").arg("--target-dir").arg(tempdir.path());
+    for config in &toolchain.components.cargo_config {
+        cmd.arg("--config").arg(config);
+    }
     match profile {
         CargoProfile::Debug => {}
         CargoProfile::Release => {

collector/src/bin/collector.rs

@@ -313,6 +313,10 @@ struct LocalOptions {
     #[arg(long)]
     cargo: Option<PathBuf>,
 
+    /// Arguments passed to `cargo --config <value>`.
+    #[arg(long)]
+    cargo_config: Option<Vec<String>>,
+
     /// Exclude all benchmarks matching a prefix in this comma-separated list
     #[arg(long, value_delimiter = ',')]
     exclude: Vec<String>,
@@ -845,7 +849,7 @@ fn main_result() -> anyhow::Result<i32> {
                 *ToolchainConfig::default()
                     .rustdoc(opts.rustdoc.as_deref())
                     .clippy(opts.clippy.as_deref())
-                    .cargo(local.cargo.as_deref())
+                    .cargo(local.cargo.as_deref(), local.cargo_config.as_deref())
                     .id(local.id.as_deref()),
                 "",
                 target_triple,
@@ -1070,7 +1074,7 @@ fn main_result() -> anyhow::Result<i32> {
                         *ToolchainConfig::default()
                             .rustdoc(opts.rustdoc.as_deref())
                             .clippy(opts.clippy.as_deref())
-                            .cargo(local.cargo.as_deref())
+                            .cargo(local.cargo.as_deref(), local.cargo_config.as_deref())
                             .id(local.id.as_deref()),
                         suffix,
                         target_triple.clone(),
@@ -1228,7 +1232,7 @@ fn binary_stats_compile(
         &[codegen_backend],
         &local.rustc,
         *ToolchainConfig::default()
-            .cargo(local.cargo.as_deref())
+            .cargo(local.cargo.as_deref(), local.cargo_config.as_deref())
             .id(local.id.as_deref()),
         "",
         target_triple.to_string(),
@@ -1240,7 +1244,7 @@ fn binary_stats_compile(
                 &[codegen_backend2],
                 &rustc,
                 *ToolchainConfig::default()
-                    .cargo(local.cargo.as_deref())
+                    .cargo(local.cargo.as_deref(), local.cargo_config.as_deref())
                     .id(local.id.as_deref()),
                 "",
                 target_triple.to_string(),
@@ -1484,7 +1488,7 @@ fn get_local_toolchain_for_runtime_benchmarks(
         &[CodegenBackend::Llvm],
         &local.rustc,
         *ToolchainConfig::default()
-            .cargo(local.cargo.as_deref())
+            .cargo(local.cargo.as_deref(), local.cargo_config.as_deref())
             .id(local.id.as_deref()),
         "",
         target_triple.to_string(),

collector/src/compile/execute/mod.rs

@@ -180,6 +180,10 @@ impl<'a> CargoProcess<'a> {
         if let Some(c) = &self.toolchain.components.clippy {
             cmd.env("CLIPPY", &*FAKE_CLIPPY).env("CLIPPY_REAL", c);
         }
+
+        for config in &self.toolchain.components.cargo_config {
+            cmd.arg("--config").arg(config);
+        }
         cmd
     }
 

collector/src/runtime/benchmark.rs

@@ -337,6 +337,10 @@ fn start_cargo_build(
     #[cfg(feature = "precise-cachegrind")]
     command.arg("--features").arg("benchlib/precise-cachegrind");
 
+    for config in &toolchain.components.cargo_config {
+        command.arg("--config").arg(config);
+    }
+
     CargoArtifactIter::from_cargo_cmd(command)
         .map_err(|error| anyhow::anyhow!("Failed to start cargo: {:?}", error))
 }

collector/src/toolchain.rs

@@ -253,6 +253,7 @@ pub struct ToolchainComponents {
     pub rustdoc: Option<PathBuf>,
     pub clippy: Option<PathBuf>,
     pub cargo: PathBuf,
+    pub cargo_config: Vec<String>,
     pub lib_rustc: Option<PathBuf>,
     pub lib_std: Option<PathBuf>,
     pub lib_test: Option<PathBuf>,
@@ -329,6 +330,8 @@ pub struct ToolchainConfig<'a> {
     rustdoc: Option<&'a Path>,
     clippy: Option<&'a Path>,
     cargo: Option<&'a Path>,
+    /// For `cargo --config <value>`.
+    cargo_config: Option<&'a [String]>,
     id: Option<&'a str>,
 }
 
@@ -343,8 +346,9 @@ impl<'a> ToolchainConfig<'a> {
         self
     }
 
-    pub fn cargo(&mut self, cargo: Option<&'a Path>) -> &mut Self {
+    pub fn cargo(&mut self, cargo: Option<&'a Path>, config: Option<&'a [String]>) -> &mut Self {
         self.cargo = cargo;
+        self.cargo_config = config;
         self
     }
 
@@ -520,13 +524,16 @@ pub fn get_local_toolchain(
         debug!("found cargo: {:?}", &cargo);
         cargo
     };
-
     let lib_dir = get_lib_dir_from_rustc(&rustc).context("Cannot find libdir for rustc")?;
 
+    let mut components =
+        ToolchainComponents::from_binaries_and_libdir(rustc, rustdoc, clippy, cargo, &lib_dir)?;
+    components.cargo_config = toolchain_config
+        .cargo_config
+        .map(|c| c.into())
+        .unwrap_or_default();
     Ok(Toolchain {
-        components: ToolchainComponents::from_binaries_and_libdir(
-            rustc, rustdoc, clippy, cargo, &lib_dir,
-        )?,
+        components,
         id,
         triple: target_triple,
     })