Auto merge of #33282 - alexcrichton:rustbuild-crate-tests, r=brson

rustbuild: Add support for crate tests + doctests

This commit adds support to rustbuild to run crate unit tests (those defined by
`#[test]`) as well as documentation tests. All tests are powered by `cargo test`
under the hood.

Each step requires the `libtest` library is built for that corresponding stage.
Ideally the `test` crate would be a dev-dependency, but for now it's just easier
to ensure that we sequence everything in the right order.

Currently no filtering is implemented, so there's not actually a method of
testing *only* libstd or *only* libcore, but rather entire swaths of crates are
tested all at once.

A few points of note here are:

* The `coretest` and `collectionstest` crates are just listed as `[[test]]`
  entires for `cargo test` to naturally pick up. This mean that `cargo test -p
  core` actually runs all the tests for libcore.
* Libraries that aren't tested all mention `test = false` in their `Cargo.toml`
* Crates aren't currently allowed to have dev-dependencies due to
  rust-lang/cargo#860, but we can likely alleviate this restriction once
  workspaces are implemented.

cc #31590

1 files changed, 16 insertions, 0 deletions

diff --git a/src/liballoc_jemalloc/build.rs b/src/liballoc_jemalloc/build.rs
index 5d521913b48..33a675331ab 100644
--- a/src/liballoc_jemalloc/build.rs
+++ b/src/liballoc_jemalloc/build.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![deny(warnings)]
+
 extern crate build_helper;
 extern crate gcc;
 
@@ -18,6 +20,7 @@ use build_helper::run;
 
 fn main() {
     println!("cargo:rustc-cfg=cargobuild");
+    println!("cargo:rerun-if-changed=build.rs");
 
     let target = env::var("TARGET").unwrap();
     let host = env::var("HOST").unwrap();
@@ -40,6 +43,19 @@ fn main() {
     let cflags = compiler.args().iter().map(|s| s.to_str().unwrap())
                          .collect::<Vec<_>>().join(" ");
 
+    let mut stack = src_dir.join("../jemalloc")
+                           .read_dir().unwrap()
+                           .map(|e| e.unwrap())
+                           .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());
+        }
+    }
+
     let mut cmd = Command::new("sh");
     cmd.arg(src_dir.join("../jemalloc/configure").to_str().unwrap()
                    .replace("C:\\", "/c/")