Simplify ProcessBuilder modification

Updated Cargo, needs rust-lang/cargo@f46d485

Author: Xanewok

Cargo.lock

@@ -8,10 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use cargo::core::{PackageId, Shell, Target, Workspace, Verbosity};
+use cargo::core::{PackageId, Shell, Target, TargetKind, Workspace, Verbosity};
 use cargo::ops::{compile_with_exec, Executor, Context, Packages, CompileOptions, CompileMode, CompileFilter, Unit};
 use cargo::util::{Config as CargoConfig, ProcessBuilder, homedir, important_paths, ConfigValue, CargoResult};
-use cargo::util::errors::{CargoErrorKind, process_error};
 use serde_json;
 
 use data::Analysis;
@@ -269,7 +268,7 @@ impl Executor for RlsExecutor {
         self.is_primary_crate(id)
     }
 
-    fn exec(&self, cargo_cmd: ProcessBuilder, id: &PackageId, _target: &Target) -> CargoResult<()> {
+    fn exec(&self, cargo_cmd: ProcessBuilder, id: &PackageId, target: &Target) -> CargoResult<()> {
         // Delete any stale data. We try and remove any json files with
         // the same crate name as Cargo would emit. This includes files
         // with the same crate name but different hashes, e.g., those
@@ -294,37 +293,25 @@ impl Executor for RlsExecutor {
             }
         }
 
-        let rustc_exe = env::var("RUSTC").unwrap_or(env::args().next().unwrap());
-        let mut cmd = Command::new(&rustc_exe);
+        // Cargo should handle `$RUSTC` wrapper override already
+        let mut cmd = cargo_cmd.clone();
         cmd.env(::RUSTC_SHIM_ENV_VAR_NAME, "1");
 
         // We only want to intercept rustc call targeting current crate to cache
         // args/envs generated by cargo so we can run only rustc later ourselves
         // Currently we don't cache nor modify build script args
-        let is_build_script = crate_name == "build_script_build";
+        let is_build_script = *target.kind() == TargetKind::CustomBuild;
         if !self.is_primary_crate(id) || is_build_script {
             let build_script_notice = if is_build_script {" (build script)"} else {""};
             trace!("rustc not intercepted - {}{}", id.name(), build_script_notice);
 
+            // Recreate the command, minus -Zsave-analysis.
             if ::CRATE_BLACKLIST.contains(&&*crate_name) {
-                // Recreate the command, minus -Zsave-analysis.
-                for a in cargo_args {
-                    if a != "-Zsave-analysis" {
-                        cmd.arg(a);
-                    }
-                }
-                cmd.envs(cargo_cmd.get_envs().iter().filter_map(|(k, v)| v.as_ref().map(|v| (k, v))));
-                if let Some(cwd) = cargo_cmd.get_cwd() {
-                    cmd.current_dir(cwd);
-                }
-                return match cmd.status() {
-                    Ok(ref e) if e.success() => Ok(()),
-                    _ => Err(CargoErrorKind::ProcessErrorKind(process_error(
-                                "process didn't exit successfully", None, None)).into()),
-                };
-            } else {
-                return cargo_cmd.exec();
+                let args: Vec<_> = cmd.get_args().iter().cloned()
+                    .filter(|x| x != "Zsave-analysis").collect();
+                cmd.args_replace(&args);
             }
+            return cmd.exec();
         }
 
         trace!("rustc intercepted - args: {:?} envs: {:?}", cargo_args, cargo_cmd.get_envs());
@@ -367,25 +354,22 @@ impl Executor for RlsExecutor {
             // so the dep-info is ready by the time we return from this callback.
             // NB: In `workspace_mode` regular compilation is performed here (and we don't
             // only calculate dep-info) so it should fix the problem mentioned above.
-            // Since ProcessBuilder doesn't allow to modify args, we need to create
-            // our own command here from scratch here.
-            for a in &args {
-                // Emitting only dep-info is possible only for final crate type, as
-                // as others may emit required metadata for dependent crate types
-                if a.starts_with("--emit") && is_final_crate_type && !self.workspace_mode {
-                    cmd.arg("--emit=dep-info");
-                } else if a != "-Zsave-analysis" {
-                    cmd.arg(a);
-                }
-            }
-            cmd.envs(cargo_cmd.get_envs().iter().filter_map(|(k, v)| v.as_ref().map(|v| (k, v))));
-            if let Some(cwd) = cargo_cmd.get_cwd() {
-                cmd.current_dir(cwd);
-            }
+            let modified = args.iter()
+                .filter(|a| *a != "-Zsave-analysis")
+                .map(|a| {
+                    // Emitting only dep-info is possible only for final crate type, as
+                    // as others may emit required metadata for dependent crate types
+                    if a.starts_with("--emit") && is_final_crate_type && !self.workspace_mode {
+                        "--emit=dep-info"
+                    } else { a }
+                })
+                .collect::<Vec<_>>();
+            cmd.args_replace(&modified);
         }
 
         // Prepare modified cargo-generated args/envs for future rustc calls
-        args.insert(0, rustc_exe);
+        let rustc = cargo_cmd.get_program().to_owned().into_string().unwrap();
+        args.insert(0, rustc);
         let envs = cargo_cmd.get_envs().clone();
 
         if self.workspace_mode {
@@ -405,7 +389,7 @@ impl Executor for RlsExecutor {
                 _ => {}
             }
         } else {
-            cmd.status().expect("Couldn't execute rustc");
+            cmd.exec()?;
         }
 
         // Finally, store the modified cargo-generated args/envs for future rustc calls