feat: run benchmarks in non-bench targets

src/app.rs

@@ -4,6 +4,7 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 
 use anyhow::{anyhow, Result};
+use cargo::util::command_prelude::CompileMode;
 use cargo::{
     core::Workspace,
     ops::CompileOptions,
@@ -147,7 +148,9 @@ fn build_target(cargo_options: &CargoOpts, workspace: &Workspace) -> Result<Path
             .map(|unit_output| unit_output.path.clone())
             .ok_or_else(|| anyhow!("no benchmark '{}'", bench))
     } else {
-        match result.binaries.as_slice() {
+        let unit_outputs =
+            if cargo_options.mode == CompileMode::Bench { &result.tests } else { &result.binaries };
+        match unit_outputs.as_slice() {
             [unit_output] => Ok(unit_output.path.clone()),
             [] => Err(anyhow!("no targets found")),
             other => Err(anyhow!(
@@ -166,10 +169,9 @@ fn build_target(cargo_options: &CargoOpts, workspace: &Workspace) -> Result<Path
 /// This additionally filters options based on user args, so that Cargo
 /// builds as little as possible.
 fn make_compile_opts(cargo_options: &CargoOpts, cfg: &Config) -> Result<CompileOptions> {
-    use cargo::core::compiler::CompileMode;
     use cargo::ops::CompileFilter;
 
-    let mut compile_options = CompileOptions::new(cfg, CompileMode::Build)?;
+    let mut compile_options = CompileOptions::new(cfg, cargo_options.mode)?;
     let profile = &cargo_options.profile;
 
     compile_options.build_config.requested_profile = InternedString::new(profile);

src/instruments.rs

@@ -456,8 +456,10 @@ pub(crate) fn profile_target(
 
     command.arg(target_filepath);
 
-    if !app_config.target_args.is_empty() {
-        command.args(app_config.target_args.as_slice());
+    let bench_args = app_config.benchmarks.then_some("--bench".to_string());
+    let target_args = bench_args.iter().chain(&app_config.target_args).collect::<Vec<_>>();
+    if !target_args.is_empty() {
+        command.args(target_args.as_slice());
     }
 
     let output = command.output()?;

src/opt.rs

@@ -3,6 +3,7 @@
 use anyhow::Result;
 use cargo::core::resolver::CliFeatures;
 use cargo::ops::Packages;
+use cargo::util::command_prelude::CompileMode;
 use std::fmt;
 use std::path::PathBuf;
 use structopt::StructOpt;
@@ -53,6 +54,8 @@ pub(crate) struct AppConfig {
     bin: Option<String>,
 
     /// Benchmark target to run
+    ///
+    /// Use --benchmarks to execute benchmarks in non-bench targets.
     #[structopt(long, group = "target", value_name = "NAME")]
     bench: Option<String>,
 
@@ -64,6 +67,10 @@ pub(crate) struct AppConfig {
     #[structopt(long, value_name = "NAME")]
     profile: Option<String>,
 
+    /// Execute benchmarks like `cargo bench`.
+    #[structopt(long)]
+    pub(crate) benchmarks: bool,
+
     /// Output .trace file to the given path
     ///
     /// Defaults to `target/instruments/{name}_{template-name}_{date}.trace`.
@@ -161,6 +168,7 @@ impl fmt::Display for Target {
 
 /// Cargo-specific options
 pub(crate) struct CargoOpts {
+    pub(crate) mode: CompileMode,
     pub(crate) package: Package,
     pub(crate) target: Target,
     pub(crate) profile: String,
@@ -169,6 +177,7 @@ pub(crate) struct CargoOpts {
 
 impl AppConfig {
     pub(crate) fn to_cargo_opts(&self) -> Result<CargoOpts> {
+        let mode = if self.benchmarks { CompileMode::Bench } else { CompileMode::Build };
         let package = self.get_package();
         let target = self.get_target();
         let features = self.features.clone().map(|s| vec![s]).unwrap_or_default();
@@ -177,11 +186,17 @@ impl AppConfig {
             self.all_features,
             !self.no_default_features,
         )?;
-        let profile = self
-            .profile
-            .clone()
-            .unwrap_or_else(|| (if self.release { "release" } else { "dev" }).to_owned());
-        Ok(CargoOpts { package, target, profile, features })
+        let profile = self.profile.clone().unwrap_or_else(|| {
+            (if self.release {
+                "release"
+            } else if self.benchmarks {
+                "bench"
+            } else {
+                "dev"
+            })
+            .to_owned()
+        });
+        Ok(CargoOpts { mode, package, target, profile, features })
     }
 
     fn get_package(&self) -> Package {