core::compiler: remove Executor trait

Signed-off-by: Nick Cameron <nrc@ncameron.org>

src/cargo/core/compiler/context/mod.rs

@@ -18,9 +18,7 @@ use super::job_queue::JobQueue;
 use super::layout::Layout;
 use super::lto::Lto;
 use super::unit_graph::UnitDep;
-use super::{
-    BuildContext, Compilation, CompileKind, CompileMode, Executor, FileFlavor, RustDocFingerprint,
-};
+use super::{BuildContext, Compilation, CompileKind, CompileMode, FileFlavor, RustDocFingerprint};
 
 mod compilation_files;
 use self::compilation_files::CompilationFiles;
@@ -126,7 +124,7 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
 
     /// Starts compilation, waits for it to finish, and returns information
     /// about the result of compilation.
-    pub fn compile(mut self, exec: &Arc<dyn Executor>) -> CargoResult<Compilation<'cfg>> {
+    pub fn compile(mut self) -> CargoResult<Compilation<'cfg>> {
         let mut queue = JobQueue::new(self.bcx);
         let mut plan = BuildPlan::new();
         let build_plan = self.bcx.build_config.build_plan;
@@ -156,7 +154,7 @@ impl<'a, 'cfg> Context<'a, 'cfg> {
             // function which will run everything in order with proper
             // parallelism.
             let force_rebuild = self.bcx.build_config.force_rebuild;
-            super::compile(&mut self, &mut queue, &mut plan, unit, exec, force_rebuild)?;
+            super::compile(&mut self, &mut queue, &mut plan, unit, force_rebuild)?;
         }
 
         // Now that we've got the full job queue and we've done all our

src/cargo/core/compiler/mod.rs

@@ -90,60 +90,11 @@ impl LinkType {
     }
 }
 
-/// A glorified callback for executing calls to rustc. Rather than calling rustc
-/// directly, we'll use an `Executor`, giving clients an opportunity to intercept
-/// the build calls.
-pub trait Executor: Send + Sync + 'static {
-    /// Called after a rustc process invocation is prepared up-front for a given
-    /// unit of work (may still be modified for runtime-known dependencies, when
-    /// the work is actually executed).
-    fn init(&self, _cx: &Context<'_, '_>, _unit: &Unit) {}
-
-    /// In case of an `Err`, Cargo will not continue with the build process for
-    /// this package.
-    fn exec(
-        &self,
-        cmd: &ProcessBuilder,
-        id: PackageId,
-        target: &Target,
-        mode: CompileMode,
-        on_stdout_line: &mut dyn FnMut(&str) -> CargoResult<()>,
-        on_stderr_line: &mut dyn FnMut(&str) -> CargoResult<()>,
-    ) -> CargoResult<()>;
-
-    /// Queried when queuing each unit of work. If it returns true, then the
-    /// unit will always be rebuilt, independent of whether it needs to be.
-    fn force_rebuild(&self, _unit: &Unit) -> bool {
-        false
-    }
-}
-
-/// A `DefaultExecutor` calls rustc without doing anything else. It is Cargo's
-/// default behaviour.
-#[derive(Copy, Clone)]
-pub struct DefaultExecutor;
-
-impl Executor for DefaultExecutor {
-    fn exec(
-        &self,
-        cmd: &ProcessBuilder,
-        _id: PackageId,
-        _target: &Target,
-        _mode: CompileMode,
-        on_stdout_line: &mut dyn FnMut(&str) -> CargoResult<()>,
-        on_stderr_line: &mut dyn FnMut(&str) -> CargoResult<()>,
-    ) -> CargoResult<()> {
-        cmd.exec_with_streaming(on_stdout_line, on_stderr_line, false)
-            .map(drop)
-    }
-}
-
 fn compile<'cfg>(
     cx: &mut Context<'_, 'cfg>,
     jobs: &mut JobQueue<'cfg>,
     plan: &mut BuildPlan,
     unit: &Unit,
-    exec: &Arc<dyn Executor>,
     force_rebuild: bool,
 ) -> CargoResult<()> {
     let bcx = cx.bcx;
@@ -163,15 +114,14 @@ fn compile<'cfg>(
         // We run these targets later, so this is just a no-op for now.
         Job::new_fresh()
     } else if build_plan {
-        Job::new_dirty(rustc(cx, unit, &exec.clone())?)
+        Job::new_dirty(rustc(cx, unit)?)
     } else {
-        let force = exec.force_rebuild(unit) || force_rebuild;
-        let mut job = fingerprint::prepare_target(cx, unit, force)?;
+        let mut job = fingerprint::prepare_target(cx, unit, force_rebuild)?;
         job.before(if job.freshness() == Freshness::Dirty {
             let work = if unit.mode.is_doc() || unit.mode.is_doc_scrape() {
                 rustdoc(cx, unit)?
             } else {
-                rustc(cx, unit, exec)?
+                rustc(cx, unit)?
             };
             work.then(link_targets(cx, unit, false)?)
         } else {
@@ -198,7 +148,7 @@ fn compile<'cfg>(
     // Be sure to compile all dependencies of this target as well.
     let deps = Vec::from(cx.unit_deps(unit)); // Create vec due to mutable borrow.
     for dep in deps {
-        compile(cx, jobs, plan, &dep.unit, exec, false)?;
+        compile(cx, jobs, plan, &dep.unit, false)?;
     }
     if build_plan {
         plan.add(cx, unit)?;
@@ -207,7 +157,7 @@ fn compile<'cfg>(
     Ok(())
 }
 
-fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> CargoResult<Work> {
+fn rustc(cx: &mut Context<'_, '_>, unit: &Unit) -> CargoResult<Work> {
     let mut rustc = prepare_rustc(cx, &unit.target.rustc_crate_types(), unit)?;
     let build_plan = cx.bcx.build_config.build_plan;
 
@@ -248,10 +198,6 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
     let mut output_options = OutputOptions::new(cx, unit);
     let package_id = unit.pkg.package_id();
     let target = Target::clone(&unit.target);
-    let mode = unit.mode;
-
-    exec.init(cx, unit);
-    let exec = exec.clone();
 
     let root_output = cx.files().host_dest().to_path_buf();
     let target_dir = cx.bcx.ws.target_dir().into_path_unlocked();
@@ -339,38 +285,37 @@ fn rustc(cx: &mut Context<'_, '_>, unit: &Unit, exec: &Arc<dyn Executor>) -> Car
         if build_plan {
             state.build_plan(buildkey, rustc.clone(), outputs.clone());
         } else {
-            exec.exec(
-                &rustc,
-                package_id,
-                &target,
-                mode,
-                &mut |line| on_stdout_line(state, line, package_id, &target),
-                &mut |line| {
-                    on_stderr_line(
-                        state,
-                        line,
-                        package_id,
-                        &manifest_path,
-                        &target,
-                        &mut output_options,
-                    )
-                },
-            )
-            .map_err(verbose_if_simple_exit_code)
-            .with_context(|| {
-                // adapted from rustc_errors/src/lib.rs
-                let warnings = match output_options.warnings_seen {
-                    0 => String::new(),
-                    1 => "; 1 warning emitted".to_string(),
-                    count => format!("; {} warnings emitted", count),
-                };
-                let errors = match output_options.errors_seen {
-                    0 => String::new(),
-                    1 => " due to previous error".to_string(),
-                    count => format!(" due to {} previous errors", count),
-                };
-                format!("could not compile `{}`{}{}", name, errors, warnings)
-            })?;
+            rustc
+                .exec_with_streaming(
+                    &mut |line| on_stdout_line(state, line, package_id, &target),
+                    &mut |line| {
+                        on_stderr_line(
+                            state,
+                            line,
+                            package_id,
+                            &manifest_path,
+                            &target,
+                            &mut output_options,
+                        )
+                    },
+                    false,
+                )
+                .map(drop)
+                .map_err(verbose_if_simple_exit_code)
+                .with_context(|| {
+                    // adapted from rustc_errors/src/lib.rs
+                    let warnings = match output_options.warnings_seen {
+                        0 => String::new(),
+                        1 => "; 1 warning emitted".to_string(),
+                        count => format!("; {} warnings emitted", count),
+                    };
+                    let errors = match output_options.errors_seen {
+                        0 => String::new(),
+                        1 => " due to previous error".to_string(),
+                        count => format!(" due to {} previous errors", count),
+                    };
+                    format!("could not compile `{}`{}{}", name, errors, warnings)
+                })?;
             // Exec should never return with success *and* generate an error.
             debug_assert_eq!(output_options.errors_seen, 0);
         }

src/cargo/ops/cargo_compile/mod.rs

@@ -32,15 +32,14 @@
 use std::collections::{HashMap, HashSet};
 use std::fmt::Write;
 use std::hash::{Hash, Hasher};
-use std::sync::Arc;
 
 use crate::core::compiler::rustdoc::RustdocScrapeExamples;
 use crate::core::compiler::unit_dependencies::{build_unit_dependencies, IsArtifact};
 use crate::core::compiler::unit_graph::{self, UnitDep, UnitGraph};
+use crate::core::compiler::UnitInterner;
 use crate::core::compiler::{standard_lib, CrateType, TargetInfo};
 use crate::core::compiler::{BuildConfig, BuildContext, Compilation, Context};
 use crate::core::compiler::{CompileKind, CompileMode, CompileTarget, RustcTargetData, Unit};
-use crate::core::compiler::{DefaultExecutor, Executor, UnitInterner};
 use crate::core::profiles::{Profiles, UnitFor};
 use crate::core::resolver::features::{self, CliFeatures, FeaturesFor};
 use crate::core::resolver::{HasDevUnits, Resolve};
@@ -115,32 +114,14 @@ impl CompileOptions {
     }
 }
 
-/// Compiles!
-///
-/// This uses the [`DefaultExecutor`]. To use a custom [`Executor`], see [`compile_with_exec`].
 pub fn compile<'a>(ws: &Workspace<'a>, options: &CompileOptions) -> CargoResult<Compilation<'a>> {
-    let exec: Arc<dyn Executor> = Arc::new(DefaultExecutor);
-    compile_with_exec(ws, options, &exec)
-}
-
-/// Like [`compile`] but allows specifying a custom [`Executor`]
-/// that will be able to intercept build calls and add custom logic.
-///
-/// [`compile`] uses [`DefaultExecutor`] which just passes calls through.
-pub fn compile_with_exec<'a>(
-    ws: &Workspace<'a>,
-    options: &CompileOptions,
-    exec: &Arc<dyn Executor>,
-) -> CargoResult<Compilation<'a>> {
     ws.emit_warnings()?;
-    compile_ws(ws, options, exec)
+    compile_ws(ws, options)
 }
 
-/// Like [`compile_with_exec`] but without warnings from manifest parsing.
 pub fn compile_ws<'a>(
     ws: &Workspace<'a>,
     options: &CompileOptions,
-    exec: &Arc<dyn Executor>,
 ) -> CargoResult<Compilation<'a>> {
     let interner = UnitInterner::new();
     let bcx = create_bcx(ws, options, &interner)?;
@@ -150,7 +131,7 @@ pub fn compile_ws<'a>(
     }
     let _p = profile::start("compiling");
     let cx = Context::new(&bcx)?;
-    cx.compile(exec)
+    cx.compile()
 }
 
 /// Executes `rustc --print <VALUE>`.

src/cargo/ops/cargo_install.rs

@@ -1,9 +1,8 @@
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::path::{Path, PathBuf};
-use std::sync::Arc;
 use std::{env, fs};
 
-use crate::core::compiler::{CompileKind, DefaultExecutor, Executor, Freshness, UnitOutput};
+use crate::core::compiler::{CompileKind, Freshness, UnitOutput};
 use crate::core::{Dependency, Edition, Package, PackageId, Source, SourceId, Workspace};
 use crate::ops::CompileFilter;
 use crate::ops::{common_for_install_and_uninstall::*, FilterRule};
@@ -296,8 +295,7 @@ impl<'cfg, 'a> InstallablePackage<'cfg, 'a> {
 
         self.check_yanked_install()?;
 
-        let exec: Arc<dyn Executor> = Arc::new(DefaultExecutor);
-        let compile = ops::compile_ws(&self.ws, self.opts, &exec).with_context(|| {
+        let compile = ops::compile_ws(&self.ws, self.opts).with_context(|| {
             if let Some(td) = td_opt.take() {
                 // preserve the temporary directory, so the user can inspect it
                 td.into_path();

src/cargo/ops/cargo_package.rs

@@ -4,10 +4,9 @@ use std::io::prelude::*;
 use std::io::SeekFrom;
 use std::path::{Path, PathBuf};
 use std::rc::Rc;
-use std::sync::Arc;
 use std::task::Poll;
 
-use crate::core::compiler::{BuildConfig, CompileMode, DefaultExecutor, Executor};
+use crate::core::compiler::{BuildConfig, CompileMode};
 use crate::core::resolver::CliFeatures;
 use crate::core::{Feature, Shell, Verbosity, Workspace};
 use crate::core::{Package, PackageId, PackageSet, Resolve, SourceId};
@@ -835,8 +834,7 @@ fn run_verify(
         None
     };
 
-    let exec: Arc<dyn Executor> = Arc::new(DefaultExecutor);
-    ops::compile_with_exec(
+    ops::compile(
         &ws,
         &ops::CompileOptions {
             build_config: BuildConfig::new(
@@ -857,7 +855,6 @@ fn run_verify(
             rustdoc_document_private_items: false,
             honor_rust_version: true,
         },
-        &exec,
     )?;
 
     // Check that `build.rs` didn't modify any files in the `src` directory.

src/cargo/ops/mod.rs

@@ -2,7 +2,7 @@ use crate::sources::CRATES_IO_DOMAIN;
 
 pub use self::cargo_clean::{clean, CleanOptions};
 pub use self::cargo_compile::{
-    compile, compile_with_exec, compile_ws, create_bcx, print, resolve_all_features, CompileOptions,
+    compile, compile_ws, create_bcx, print, resolve_all_features, CompileOptions,
 };
 pub use self::cargo_compile::{CompileFilter, FilterRule, LibRule, Packages};
 pub use self::cargo_doc::{doc, DocOptions};