Auto merge of #39329 - petrochenkov:rb2, r=alexcrichton

rustbuild: Build jemalloc and libbacktrace only once (take 2)

This is a rebase of #38583 without any additions, but with implemented @alexcrichton's suggestions.
~~This includes `exists(Makefile)` => `cfg(stage0)` suggestion... but it will break cross-compilation, no? Are `libstd/liballoc_jemalloc` cross-compiled for `target != host` built during `stage0`?~~

r? @alexcrichton

Author: bors

src/Cargo.lock

@@ -383,7 +383,7 @@ pub fn krate(build: &Build,
                 // helper crate, not tested. If it leaks through then it ends up
                 // messing with various mtime calculations and such.
                 if !name.contains("jemalloc") && name != "build_helper" {
-                    cargo.arg("-p").arg(name);
+                    cargo.arg("-p").arg(&format!("{}:0.0.0", name));
                 }
                 for dep in build.crates[name].deps.iter() {
                     if visited.insert(dep) {

src/bootstrap/check.rs

@@ -21,10 +21,10 @@ use std::fs::{self, File};
 use std::path::{Path, PathBuf};
 use std::process::Command;
 
-use build_helper::output;
+use build_helper::{output, mtime};
 use filetime::FileTime;
 
-use util::{exe, libdir, mtime, is_dylib, copy};
+use util::{exe, libdir, is_dylib, copy};
 use {Build, Compiler, Mode};
 
 /// Build the standard library.

src/bootstrap/compile.rs

@@ -22,7 +22,8 @@ use std::io::prelude::*;
 use std::process::Command;
 
 use {Build, Compiler, Mode};
-use util::{up_to_date, cp_r};
+use util::cp_r;
+use build_helper::up_to_date;
 
 /// Invoke `rustbook` as compiled in `stage` for `target` for the doc book
 /// `name` into the `out` path.

src/bootstrap/doc.rs

@@ -66,6 +66,7 @@
 
 #![deny(warnings)]
 
+#[macro_use]
 extern crate build_helper;
 extern crate cmake;
 extern crate filetime;
@@ -83,24 +84,9 @@ use std::fs::{self, File};
 use std::path::{Component, PathBuf, Path};
 use std::process::Command;
 
-use build_helper::{run_silent, output};
+use build_helper::{run_silent, output, mtime};
 
-use util::{exe, mtime, libdir, add_lib_path};
-
-/// A helper macro to `unwrap` a result except also print out details like:
-///
-/// * The file/line of the panic
-/// * The expression that failed
-/// * The error itself
-///
-/// This is currently used judiciously throughout the build system rather than
-/// using a `Result` with `try!`, but this may change one day...
-macro_rules! t {
-    ($e:expr) => (match $e {
-        Ok(e) => e,
-        Err(e) => panic!("{} failed with {}", stringify!($e), e),
-    })
-}
+use util::{exe, libdir, add_lib_path};
 
 mod cc;
 mod channel;
@@ -482,7 +468,8 @@ impl Build {
         //
         // These variables are primarily all read by
         // src/bootstrap/bin/{rustc.rs,rustdoc.rs}
-        cargo.env("RUSTC", self.out.join("bootstrap/debug/rustc"))
+        cargo.env("RUSTBUILD_NATIVE_DIR", self.native_dir(target))
+             .env("RUSTC", self.out.join("bootstrap/debug/rustc"))
              .env("RUSTC_REAL", self.compiler_path(compiler))
              .env("RUSTC_STAGE", stage.to_string())
              .env("RUSTC_DEBUGINFO", self.config.rust_debuginfo.to_string())
@@ -746,10 +733,15 @@ impl Build {
         }
     }
 
+    /// Directory for libraries built from C/C++ code and shared between stages.
+    fn native_dir(&self, target: &str) -> PathBuf {
+        self.out.join(target).join("native")
+    }
+
     /// Root output directory for rust_test_helpers library compiled for
     /// `target`
     fn test_helpers_out(&self, target: &str) -> PathBuf {
-        self.out.join(target).join("rust-test-helpers")
+        self.native_dir(target).join("rust-test-helpers")
     }
 
     /// Adds the compiler's directory of dynamic libraries to `cmd`'s dynamic

src/bootstrap/lib.rs

@@ -28,7 +28,8 @@ use cmake;
 use gcc;
 
 use Build;
-use util::{self, up_to_date};
+use util;
+use build_helper::up_to_date;
 
 /// Compile LLVM for `target`.
 pub fn llvm(build: &Build, target: &str) {

src/bootstrap/native.rs

@@ -20,8 +20,6 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::time::Instant;
 
-use filetime::FileTime;
-
 /// Returns the `name` as the filename of a static library for `target`.
 pub fn staticlib(name: &str, target: &str) -> String {
     if target.contains("windows") {
@@ -31,13 +29,6 @@ pub fn staticlib(name: &str, target: &str) -> String {
     }
 }
 
-/// Returns the last-modified time for `path`, or zero if it doesn't exist.
-pub fn mtime(path: &Path) -> FileTime {
-    fs::metadata(path).map(|f| {
-        FileTime::from_last_modification_time(&f)
-    }).unwrap_or(FileTime::zero())
-}
-
 /// Copies a file from `src` to `dst`, attempting to use hard links and then
 /// falling back to an actually filesystem copy if necessary.
 pub fn copy(src: &Path, dst: &Path) {
@@ -132,34 +123,6 @@ pub fn add_lib_path(path: Vec<PathBuf>, cmd: &mut Command) {
     cmd.env(dylib_path_var(), t!(env::join_paths(list)));
 }
 
-/// Returns whether `dst` is up to date given that the file or files in `src`
-/// are used to generate it.
-///
-/// Uses last-modified time checks to verify this.
-pub fn up_to_date(src: &Path, dst: &Path) -> bool {
-    let threshold = mtime(dst);
-    let meta = match fs::metadata(src) {
-        Ok(meta) => meta,
-        Err(e) => panic!("source {:?} failed to get metadata: {}", src, e),
-    };
-    if meta.is_dir() {
-        dir_up_to_date(src, &threshold)
-    } else {
-        FileTime::from_last_modification_time(&meta) <= threshold
-    }
-}
-
-fn dir_up_to_date(src: &Path, threshold: &FileTime) -> bool {
-    t!(fs::read_dir(src)).map(|e| t!(e)).all(|e| {
-        let meta = t!(e.metadata());
-        if meta.is_dir() {
-            dir_up_to_date(&e.path(), threshold)
-        } else {
-            FileTime::from_last_modification_time(&meta) < *threshold
-        }
-    })
-}
-
 /// Returns the environment variable which the dynamic library lookup path
 /// resides in for this platform.
 pub fn dylib_path_var() -> &'static str {

src/bootstrap/util.rs

@@ -6,3 +6,6 @@ authors = ["The Rust Project Developers"]
 [lib]
 name = "build_helper"
 path = "lib.rs"
+
+[dependencies]
+filetime = "0.1"

src/build_helper/Cargo.toml

@@ -10,9 +10,30 @@
 
 #![deny(warnings)]
 
+extern crate filetime;
+
+use std::fs;
 use std::process::{Command, Stdio};
 use std::path::{Path, PathBuf};
 
+use filetime::FileTime;
+
+/// A helper macro to `unwrap` a result except also print out details like:
+///
+/// * The file/line of the panic
+/// * The expression that failed
+/// * The error itself
+///
+/// This is currently used judiciously throughout the build system rather than
+/// using a `Result` with `try!`, but this may change one day...
+#[macro_export]
+macro_rules! t {
+    ($e:expr) => (match $e {
+        Ok(e) => e,
+        Err(e) => panic!("{} failed with {}", stringify!($e), e),
+    })
+}
+
 pub fn run(cmd: &mut Command) {
     println!("running: {:?}", cmd);
     run_silent(cmd);
@@ -88,6 +109,56 @@ pub fn output(cmd: &mut Command) -> String {
     String::from_utf8(output.stdout).unwrap()
 }
 
+pub fn rerun_if_changed_anything_in_dir(dir: &Path) {
+    let mut stack = dir.read_dir().unwrap()
+                       .map(|e| e.unwrap())
+                       .filter(|e| &*e.file_name() != ".git")
+                       .collect::<Vec<_>>();
+    while let Some(entry) = stack.pop() {
+        let path = entry.path();
+        if entry.file_type().unwrap().is_dir() {
+            stack.extend(path.read_dir().unwrap().map(|e| e.unwrap()));
+        } else {
+            println!("cargo:rerun-if-changed={}", path.display());
+        }
+    }
+}
+
+/// Returns the last-modified time for `path`, or zero if it doesn't exist.
+pub fn mtime(path: &Path) -> FileTime {
+    fs::metadata(path).map(|f| {
+        FileTime::from_last_modification_time(&f)
+    }).unwrap_or(FileTime::zero())
+}
+
+/// Returns whether `dst` is up to date given that the file or files in `src`
+/// are used to generate it.
+///
+/// Uses last-modified time checks to verify this.
+pub fn up_to_date(src: &Path, dst: &Path) -> bool {
+    let threshold = mtime(dst);
+    let meta = match fs::metadata(src) {
+        Ok(meta) => meta,
+        Err(e) => panic!("source {:?} failed to get metadata: {}", src, e),
+    };
+    if meta.is_dir() {
+        dir_up_to_date(src, &threshold)
+    } else {
+        FileTime::from_last_modification_time(&meta) <= threshold
+    }
+}
+
+fn dir_up_to_date(src: &Path, threshold: &FileTime) -> bool {
+    t!(fs::read_dir(src)).map(|e| t!(e)).all(|e| {
+        let meta = t!(e.metadata());
+        if meta.is_dir() {
+            dir_up_to_date(&e.path(), threshold)
+        } else {
+            FileTime::from_last_modification_time(&meta) < *threshold
+        }
+    })
+}
+
 fn fail(s: &str) -> ! {
     println!("\n\n{}\n\n", s);
     std::process::exit(1);