rustbuild: Use an enum to indicate destination

alexcrichton · alexcrichton · commit 0788cd23ea6e · 2016-03-08T11:52:10.000-08:00
Instead of using a `is_std: bool`, instead use a more well-typed and
self-documenting enum to indicate the mode in which Cargo is being invoked.
diff --git a/src/bootstrap/build/compile.rs b/src/bootstrap/build/compile.rs
@@ -16,7 +16,7 @@ use std::process::Command;
 use build_helper::output;
 
 use build::util::{exe, staticlib, libdir, mtime, is_dylib};
-use build::{Build, Compiler};
+use build::{Build, Compiler, Mode};
 
 /// Build the standard library.
 ///
@@ -39,9 +39,10 @@ pub fn std<'a>(build: &'a Build, stage: u32, target: &str,
 
     build_startup_objects(build, target, &libdir);
 
-    let out_dir = build.cargo_out(stage, &host, true, target);
+    let out_dir = build.cargo_out(stage, &host, Mode::Libstd, target);
     build.clear_if_dirty(&out_dir, &build.compiler_path(compiler));
-    let mut cargo = build.cargo(stage, compiler, true, target, "build");
+    let mut cargo = build.cargo(stage, compiler, Mode::Libstd, Some(target),
+                                "build");
     cargo.arg("--features").arg(build.std_features())
          .arg("--manifest-path")
          .arg(build.src.join("src/rustc/std_shim/Cargo.toml"));
@@ -71,7 +72,7 @@ pub fn std_link(build: &Build,
                 compiler: &Compiler,
                 host: &str) {
     let libdir = build.sysroot_libdir(stage, host, target);
-    let out_dir = build.cargo_out(stage, compiler.host, true, target);
+    let out_dir = build.cargo_out(stage, compiler.host, Mode::Libstd, target);
 
     // If we're linking one compiler host's output into another, then we weren't
     // called from the `std` method above. In that case we clean out what's
@@ -135,10 +136,11 @@ pub fn rustc<'a>(build: &'a Build, stage: u32, target: &str,
     println!("Building stage{} compiler artifacts ({} -> {})", stage,
              host, target);
 
-    let out_dir = build.cargo_out(stage, &host, false, target);
+    let out_dir = build.cargo_out(stage, &host, Mode::Librustc, target);
     build.clear_if_dirty(&out_dir, &libstd_shim(build, stage, &host, target));
 
-    let mut cargo = build.cargo(stage, compiler, false, target, "build");
+    let mut cargo = build.cargo(stage, compiler, Mode::Librustc, Some(target),
+                                "build");
     cargo.arg("--features").arg(build.rustc_features(stage))
          .arg("--manifest-path")
          .arg(build.src.join("src/rustc/Cargo.toml"));
@@ -200,14 +202,14 @@ pub fn rustc_link(build: &Build,
                   compiler: &Compiler,
                   host: &str) {
     let libdir = build.sysroot_libdir(stage, host, target);
-    let out_dir = build.cargo_out(stage, compiler.host, false, target);
+    let out_dir = build.cargo_out(stage, compiler.host, Mode::Librustc, target);
     add_to_sysroot(&out_dir, &libdir);
 }
 
 /// Cargo's output path for the standard library in a given stage, compiled
 /// by a particular compiler for the specified target.
 fn libstd_shim(build: &Build, stage: u32, host: &str, target: &str) -> PathBuf {
-    build.cargo_out(stage, host, true, target).join("libstd_shim.rlib")
+    build.cargo_out(stage, host, Mode::Libstd, target).join("libstd_shim.rlib")
 }
 
 fn compiler_file(compiler: &Path, file: &str) -> String {
@@ -239,7 +241,8 @@ pub fn assemble_rustc(build: &Build, stage: u32, host: &str) {
         }
     }
 
-    let out_dir = build.cargo_out(stage - 1, &build.config.build, false, host);
+    let out_dir = build.cargo_out(stage - 1, &build.config.build,
+                                  Mode::Librustc, host);
 
     // Link the compiler binary itself into place
     let rustc = out_dir.join(exe("rustc", host));
diff --git a/src/bootstrap/build/doc.rs b/src/bootstrap/build/doc.rs
@@ -12,7 +12,7 @@ use std::path::Path;
 use std::fs::{self, File};
 use std::io::prelude::*;
 
-use build::{Build, Compiler};
+use build::{Build, Compiler, Mode};
 use build::util::{up_to_date, cp_r};
 
 pub fn rustbook(build: &Build, stage: u32, host: &str, name: &str, out: &Path) {
@@ -106,14 +106,14 @@ pub fn standalone(build: &Build, stage: u32, host: &str, out: &Path) {
 pub fn std(build: &Build, stage: u32, host: &str, out: &Path) {
     println!("Documenting stage{} std ({})", stage, host);
     let compiler = Compiler::new(stage, host);
-    let out_dir = build.stage_out(stage, host, true)
+    let out_dir = build.stage_out(stage, host, Mode::Libstd)
                        .join(host).join("doc");
     let rustdoc = build.tool(&compiler, "rustdoc");
     if !up_to_date(&rustdoc, &out_dir.join("std/index.html")) {
         t!(fs::remove_dir_all(&out_dir));
     }
 
-    let mut cargo = build.cargo(stage, &compiler, true, host,
+    let mut cargo = build.cargo(stage, &compiler, Mode::Libstd, Some(host),
                                 "doc");
     cargo.arg("--manifest-path")
          .arg(build.src.join("src/rustc/std_shim/Cargo.toml"))
@@ -125,13 +125,13 @@ pub fn std(build: &Build, stage: u32, host: &str, out: &Path) {
 pub fn rustc(build: &Build, stage: u32, host: &str, out: &Path) {
     println!("Documenting stage{} compiler ({})", stage, host);
     let compiler = Compiler::new(stage, host);
-    let out_dir = build.stage_out(stage, host, false)
+    let out_dir = build.stage_out(stage, host, Mode::Librustc)
                        .join(host).join("doc");
     let rustdoc = build.tool(&compiler, "rustdoc");
     if !up_to_date(&rustdoc, &out_dir.join("rustc/index.html")) {
         t!(fs::remove_dir_all(&out_dir));
     }
-    let mut cargo = build.cargo(stage, &compiler, false, host,
+    let mut cargo = build.cargo(stage, &compiler, Mode::Librustc, Some(host),
                                 "doc");
     cargo.arg("--manifest-path")
          .arg(build.src.join("src/rustc/Cargo.toml"))
diff --git a/src/bootstrap/build/mod.rs b/src/bootstrap/build/mod.rs
@@ -83,6 +83,12 @@ pub struct Build {
     compiler_rt_built: RefCell<HashMap<String, PathBuf>>,
 }
 
+pub enum Mode {
+    Libstd,
+    Librustc,
+    Tool,
+}
+
 impl Build {
     pub fn new(flags: Flags, config: Config) -> Build {
         let cwd = t!(env::current_dir());
@@ -241,14 +247,17 @@ impl Build {
     /// Cargo for the specified stage, whether or not the standard library is
     /// being built, and using the specified compiler targeting `target`.
     // FIXME: aren't stage/compiler duplicated?
-    fn cargo(&self, stage: u32, compiler: &Compiler, is_std: bool,
-             target: &str, cmd: &str) -> Command {
+    fn cargo(&self,
+             stage: u32,
+             compiler: &Compiler,
+             mode: Mode,
+             target: Option<&str>,
+             cmd: &str) -> Command {
         let mut cargo = Command::new(&self.cargo);
         let host = compiler.host;
-        let out_dir = self.stage_out(stage, host, is_std);
+        let out_dir = self.stage_out(stage, host, mode);
         cargo.env("CARGO_TARGET_DIR", out_dir)
              .arg(cmd)
-             .arg("--target").arg(target)
              .arg("-j").arg(self.jobs().to_string());
 
         // Customize the compiler we're running. Specify the compiler to cargo
@@ -265,24 +274,28 @@ impl Build {
              .env("RUSTC_SNAPSHOT", &self.rustc)
              .env("RUSTC_SYSROOT", self.sysroot(stage, host))
              .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_snapshot_libdir())
-             .env("RUSTC_FLAGS", self.rustc_flags(target).join(" "))
              .env("RUSTC_RPATH", self.config.rust_rpath.to_string())
              .env("RUSTDOC", self.tool(compiler, "rustdoc"));
 
-        // Specify some variuos options for build scripts used throughout the
-        // build.
-        //
-        // FIXME: the guard against msvc shouldn't need to be here
-        if !target.contains("msvc") {
-            cargo.env(format!("CC_{}", target), self.cc(target))
-                 .env(format!("AR_{}", target), self.ar(target))
-                 .env(format!("CFLAGS_{}", target), self.cflags(target));
-        }
+        if let Some(target) = target {
+             cargo.env("RUSTC_FLAGS", self.rustc_flags(target).join(" "));
+             cargo.arg("--target").arg(target);
+
+            // Specify some various options for build scripts used throughout
+            // the build.
+            //
+            // FIXME: the guard against msvc shouldn't need to be here
+            if !target.contains("msvc") {
+                cargo.env(format!("CC_{}", target), self.cc(target))
+                     .env(format!("AR_{}", target), self.ar(target))
+                     .env(format!("CFLAGS_{}", target), self.cflags(target));
+            }
 
-        // Environment variables *required* needed throughout the build
-        //
-        // FIXME: should update code to not require this env vars
-        cargo.env("CFG_COMPILER_HOST_TRIPLE", target);
+            // Environment variables *required* needed throughout the build
+            //
+            // FIXME: should update code to not require this env vars
+            cargo.env("CFG_COMPILER_HOST_TRIPLE", target);
+        }
 
         if self.config.verbose || self.flags.verbose {
             cargo.arg("-v");
@@ -306,7 +319,7 @@ impl Build {
 
     /// Get the specified tool next to the specified compiler
     fn tool(&self, compiler: &Compiler, tool: &str) -> PathBuf {
-        self.stage_out(compiler.stage, compiler.host, false)
+        self.stage_out(compiler.stage, compiler.host, Mode::Tool)
             .join(self.cargo_dir())
             .join(exe(tool, compiler.host))
     }
@@ -319,8 +332,8 @@ impl Build {
         let host = compiler.host;
         let stage = compiler.stage;
         let paths = vec![
-            self.cargo_out(stage, host, true, host).join("deps"),
-            self.cargo_out(stage, host, false, host).join("deps"),
+            self.cargo_out(stage, host, Mode::Libstd, host).join("deps"),
+            self.cargo_out(stage, host, Mode::Librustc, host).join("deps"),
         ];
         add_lib_path(paths, &mut cmd);
         return cmd
@@ -363,7 +376,7 @@ impl Build {
 
     fn sysroot(&self, stage: u32, host: &str) -> PathBuf {
         if stage == 0 {
-            self.stage_out(stage, host, false)
+            self.stage_out(stage, host, Mode::Librustc)
         } else {
             self.out.join(host).join(format!("stage{}", stage))
         }
@@ -377,19 +390,21 @@ impl Build {
     /// Returns the root directory for all output generated in a particular
     /// stage when running with a particular host compiler.
     ///
-    /// The `is_std` flag indicates whether the root directory is for the
-    /// bootstrap of the standard library or for the compiler.
-    fn stage_out(&self, stage: u32, host: &str, is_std: bool) -> PathBuf {
-        self.out.join(host)
-            .join(format!("stage{}{}", stage, if is_std {"-std"} else {"-rustc"}))
+    /// The mode indicates what the root directory is for.
+    fn stage_out(&self, stage: u32, host: &str, mode: Mode) -> PathBuf {
+        let suffix = match mode {
+            Mode::Libstd => "-std",
+            _ => "-rustc",
+        };
+        self.out.join(host).join(format!("stage{}{}", stage, suffix))
     }
 
     /// Returns the root output directory for all Cargo output in a given stage,
     /// running a particular comipler, wehther or not we're building the
     /// standard library, and targeting the specified architecture.
-    fn cargo_out(&self, stage: u32, host: &str, is_std: bool,
+    fn cargo_out(&self, stage: u32, host: &str, mode: Mode,
                  target: &str) -> PathBuf {
-        self.stage_out(stage, host, is_std).join(target).join(self.cargo_dir())
+        self.stage_out(stage, host, mode).join(target).join(self.cargo_dir())
     }
 
     /// Root output directory for LLVM compiled for `target`
