Change Step to be invoked with a path when in default mode.

Previously, a Step would be able to tell on its own when it was invoked
"by-default" (that is, `./x.py test` was called instead of `./x.py test
some/path`). This commit replaces that functionality, invoking each Step
with each of the paths it has specified as "should be invoked by."

For example, if a step calls `path("src/tools/cargo")` and
`path("src/doc/cargo")` then it's make_run will be called twice, with
"src/tools/cargo" and "src/doc/cargo." This makes it so that default
handling logic is in builder, instead of spread across various Steps.

However, this meant that some Step specifications needed to be updated,
since for example `rustdoc` can be built by `./x.py build
src/librustdoc` or `./x.py build src/tools/rustdoc`. A `PathSet`
abstraction is added that handles this: now, each Step can not only list
`path(...)` but also `paths(&[a, b, ...])` which will make it so that we
don't invoke it with each of the individual paths, instead invoking it
with the first path in the list (though this shouldn't be depended on).

Future work likely consists of implementing a better/easier way for a
given Step to work with "any" crate in-tree, especially those that want
to run tests, build, or check crates in the std, test, or rustc crate
trees. Currently this is rather painful to do as most of the logic is
duplicated across should_run and make_run. It seems likely this can be
abstracted away into builder somehow.

1 files changed, 22 insertions, 15 deletions

diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 83c270865c0..afd740ce548 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -113,9 +113,8 @@
 //! More documentation can be found in each respective module below, and you can
 //! also check out the `src/bootstrap/README.md` file for more information.
 
-#![deny(warnings)]
-#![allow(stable_features)]
-#![feature(associated_consts)]
+//#![deny(warnings)]
+#![feature(core_intrinsics)]
 
 #[macro_use]
 extern crate build_helper;
@@ -267,6 +266,18 @@ struct Crate {
     bench_step: String,
 }
 
+impl Crate {
+    fn is_local(&self, build: &Build) -> bool {
+        self.path.starts_with(&build.config.src) &&
+        !self.path.to_string_lossy().ends_with("_shim")
+    }
+
+    fn local_path(&self, build: &Build) -> PathBuf {
+        assert!(self.is_local(build));
+        self.path.strip_prefix(&build.config.src).unwrap().into()
+    }
+}
+
 /// The various "modes" of invoking Cargo.
 ///
 /// These entries currently correspond to the various output directories of the
@@ -949,22 +960,18 @@ impl Build {
         }
     }
 
-    /// Get a list of crates from a root crate.
-    ///
-    /// Returns Vec<(crate, path to crate, is_root_crate)>
-    fn crates(&self, root: &str) -> Vec<(Interned<String>, &Path)> {
-        let interned = INTERNER.intern_string(root.to_owned());
+    fn in_tree_crates(&self, root: &str) -> Vec<&Crate> {
         let mut ret = Vec::new();
-        let mut list = vec![interned];
+        let mut list = vec![INTERNER.intern_str(root)];
         let mut visited = HashSet::new();
         while let Some(krate) = list.pop() {
             let krate = &self.crates[&krate];
-            // If we can't strip prefix, then out-of-tree path
-            let path = krate.path.strip_prefix(&self.src).unwrap_or(&krate.path);
-            ret.push((krate.name, path));
-            for dep in &krate.deps {
-                if visited.insert(dep) && dep != "build_helper" {
-                    list.push(*dep);
+            if krate.is_local(self) {
+                ret.push(krate);
+                for dep in &krate.deps {
+                    if visited.insert(dep) && dep != "build_helper" {
+                        list.push(*dep);
+                    }
                 }
             }
         }