rustbuild: Add a link checker for documentation

Add a script to get run which verifies that `href` links in documents are
correct. We're always getting a steady stream of "fix a broken link" PRs and
issue reports, and we should probably just nip them all in the bud.

4 files changed, 44 insertions, 2 deletions

diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index 6659894a171..5de7e6957c6 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -73,7 +73,8 @@ class RustBuild:
 
         if self.rustc().startswith(self.bin_root()) and \
            (not os.path.exists(self.rustc()) or self.rustc_out_of_date()):
-            shutil.rmtree(self.bin_root())
+            if os.path.exists(self.bin_root()):
+                shutil.rmtree(self.bin_root())
             filename = "rust-std-nightly-" + self.build + ".tar.gz"
             url = "https://static.rust-lang.org/dist/" + self.snap_rustc_date()
             tarball = os.path.join(rustc_cache, filename)
diff --git a/src/bootstrap/build/check.rs b/src/bootstrap/build/check.rs
new file mode 100644
index 00000000000..19293e80217
--- /dev/null
+++ b/src/bootstrap/build/check.rs
@@ -0,0 +1,21 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::process::Command;
+
+use build::{Build, Compiler};
+
+pub fn linkcheck(build: &Build, stage: u32, host: &str) {
+    println!("Linkcheck stage{} ({})", stage, host);
+    let compiler = Compiler::new(stage, host);
+    let linkchecker = build.tool(&compiler, "linkchecker");
+    build.run(Command::new(&linkchecker)
+                     .arg(build.out.join(host).join("doc")));
+}
diff --git a/src/bootstrap/build/mod.rs b/src/bootstrap/build/mod.rs
index 825cca6563c..9f24fba5843 100644
--- a/src/bootstrap/build/mod.rs
+++ b/src/bootstrap/build/mod.rs
@@ -30,6 +30,7 @@ macro_rules! t {
 
 mod cc;
 mod channel;
+mod check;
 mod clean;
 mod compile;
 mod config;
@@ -171,6 +172,9 @@ impl Build {
                 Rustc { stage } => {
                     compile::assemble_rustc(self, stage, target.target);
                 }
+                ToolLinkchecker { stage } => {
+                    compile::tool(self, stage, target.target, "linkchecker");
+                }
                 ToolRustbook { stage } => {
                     compile::tool(self, stage, target.target, "rustbook");
                 }
@@ -195,6 +199,10 @@ impl Build {
                     doc::rustc(self, stage, target.target, &doc_out);
                 }
 
+                CheckLinkcheck { stage } => {
+                    check::linkcheck(self, stage, target.target);
+                }
+
                 Doc { .. } | // pseudo-steps
                 Check { .. } => {}
             }
diff --git a/src/bootstrap/build/step.rs b/src/bootstrap/build/step.rs
index 23c678df9ac..7921edcff55 100644
--- a/src/bootstrap/build/step.rs
+++ b/src/bootstrap/build/step.rs
@@ -46,6 +46,7 @@ macro_rules! targets {
             }),
 
             // Various tools that we can build as part of the build.
+            (tool_linkchecker, ToolLinkchecker { stage: u32 }),
             (tool_rustbook, ToolRustbook { stage: u32 }),
 
             // Steps for long-running native builds. Ideally these wouldn't
@@ -71,6 +72,7 @@ macro_rules! targets {
             // Steps for running tests. The 'check' target is just a pseudo
             // target to depend on a bunch of others.
             (check, Check { stage: u32, compiler: Compiler<'a> }),
+            (check_linkcheck, CheckLinkcheck { stage: u32 }),
         }
     }
 }
@@ -200,6 +202,8 @@ fn add_steps<'a>(build: &'a Build,
         }
 
         targets!(add_step);
+
+        panic!("unknown step: {}", step);
     }
 }
 
@@ -273,7 +277,15 @@ impl<'a> Step<'a> {
                      self.doc_std(stage)]
             }
             Source::Check { stage, compiler: _ } => {
-                vec![]
+                vec![self.check_linkcheck(stage)]
+            }
+            Source::CheckLinkcheck { stage } => {
+                vec![self.tool_linkchecker(stage), self.doc(stage)]
+            }
+
+            Source::ToolLinkchecker { stage } => {
+                vec![self.libstd(stage, self.compiler(stage))]
+            }
             Source::ToolRustbook { stage } => {
                 vec![self.librustc(stage, self.compiler(stage))]
             }