Sync all unstable features with Unstable Book; add tidy lint.

Add a tidy lint that checks for...

* Unstable Book sections with no corresponding SUMMARY.md links
* unstable features that don't have Unstable Book sections
* Unstable Book sections that don't have corresponding unstable features

Author: frewsxcv

src/Cargo.lock

@@ -146,7 +146,6 @@
 - [proc_macro](proc-macro.md)
 - [proc_macro_internals](proc-macro-internals.md)
 - [process_try_wait](process-try-wait.md)
-- [pub_restricted](pub-restricted.md)
 - [question_mark_carrier](question-mark-carrier.md)
 - [quote](quote.md)
 - [rand](rand.md)
@@ -156,11 +155,11 @@
 - [relaxed_adts](relaxed-adts.md)
 - [repr_simd](repr-simd.md)
 - [retain_hash_collection](retain-hash-collection.md)
+- [reverse_cmp_key](reverse-cmp-key.md)
 - [rt](rt.md)
 - [rustc_attrs](rustc-attrs.md)
 - [rustc_diagnostic_macros](rustc-diagnostic-macros.md)
 - [rustc_private](rustc-private.md)
-- [rustdoc](rustdoc.md)
 - [rvalue_static_promotion](rvalue-static-promotion.md)
 - [sanitizer_runtime](sanitizer-runtime.md)
 - [sanitizer_runtime_lib](sanitizer-runtime-lib.md)
@@ -181,6 +180,7 @@
 - [step_by](step-by.md)
 - [step_trait](step-trait.md)
 - [stmt_expr_attributes](stmt-expr-attributes.md)
+- [str_checked_slicing](str-checked-slicing.md)
 - [str_escape](str-escape.md)
 - [str_internals](str-internals.md)
 - [struct_field_attributes](struct-field-attributes.md)

src/doc/unstable-book/src/SUMMARY.md

@@ -0,0 +1,7 @@
+# `reverse_cmp_key`
+
+The tracking issue for this feature is: [#40893]
+
+[#40893]: https://github.com/rust-lang/rust/issues/40893
+
+------------------------

src/doc/unstable-book/src/pub-restricted.md

@@ -0,0 +1,7 @@
+# `str_checked_slicing`
+
+The tracking issue for this feature is: [#39932]
+
+[#39932]: https://github.com/rust-lang/rust/issues/39932
+
+------------------------

src/doc/unstable-book/src/reverse-cmp-key.md

@@ -4,3 +4,4 @@ version = "0.1.0"
 authors = ["Alex Crichton <[email protected]>"]
 
 [dependencies]
+regex = "0.2"

src/doc/unstable-book/src/rustdoc.md

@@ -24,8 +24,8 @@ use std::fs::File;
 use std::io::prelude::*;
 use std::path::Path;
 
-#[derive(PartialEq)]
-enum Status {
+#[derive(Debug, PartialEq)]
+pub enum Status {
     Stable,
     Removed,
     Unstable,
@@ -42,78 +42,21 @@ impl fmt::Display for Status {
     }
 }
 
-struct Feature {
-    level: Status,
-    since: String,
-    has_gate_test: bool,
+#[derive(Debug)]
+pub struct Feature {
+    pub level: Status,
+    pub since: String,
+    pub has_gate_test: bool,
 }
 
 pub fn check(path: &Path, bad: &mut bool) {
-    let mut features = collect_lang_features(&path.join("libsyntax/feature_gate.rs"));
+    let mut features = collect_lang_features(path);
     assert!(!features.is_empty());
-    let mut lib_features = HashMap::<String, Feature>::new();
-
-    let mut contents = String::new();
-    super::walk(path,
-                &mut |path| super::filter_dirs(path) || path.ends_with("src/test"),
-                &mut |file| {
-        let filename = file.file_name().unwrap().to_string_lossy();
-        if !filename.ends_with(".rs") || filename == "features.rs" ||
-           filename == "diagnostic_list.rs" {
-            return;
-        }
-
-        contents.truncate(0);
-        t!(t!(File::open(&file), &file).read_to_string(&mut contents));
 
-        for (i, line) in contents.lines().enumerate() {
-            let mut err = |msg: &str| {
-                println!("{}:{}: {}", file.display(), i + 1, msg);
-                *bad = true;
-            };
-            let level = if line.contains("[unstable(") {
-                Status::Unstable
-            } else if line.contains("[stable(") {
-                Status::Stable
-            } else {
-                continue;
-            };
-            let feature_name = match find_attr_val(line, "feature") {
-                Some(name) => name,
-                None => {
-                    err("malformed stability attribute");
-                    continue;
-                }
-            };
-            let since = match find_attr_val(line, "since") {
-                Some(name) => name,
-                None if level == Status::Stable => {
-                    err("malformed stability attribute");
-                    continue;
-                }
-                None => "None",
-            };
+    let lib_features = collect_lib_features(path, bad, &features);
+    assert!(!lib_features.is_empty());
 
-            if features.contains_key(feature_name) {
-                err("duplicating a lang feature");
-            }
-            if let Some(ref s) = lib_features.get(feature_name) {
-                if s.level != level {
-                    err("different stability level than before");
-                }
-                if s.since != since {
-                    err("different `since` than before");
-                }
-                continue;
-            }
-            lib_features.insert(feature_name.to_owned(),
-                                Feature {
-                                    level: level,
-                                    since: since.to_owned(),
-                                    has_gate_test: false,
-                                });
-        }
-    });
+    let mut contents = String::new();
 
     super::walk_many(&[&path.join("test/compile-fail"),
                        &path.join("test/compile-fail-fulldeps"),
@@ -233,8 +176,9 @@ fn test_filen_gate(filen_underscore: &str,
     return false;
 }
 
-fn collect_lang_features(path: &Path) -> HashMap<String, Feature> {
+pub fn collect_lang_features(base_src_path: &Path) -> HashMap<String, Feature> {
     let mut contents = String::new();
+    let path = base_src_path.join("libsyntax/feature_gate.rs");
     t!(t!(File::open(path)).read_to_string(&mut contents));
 
     contents.lines()
@@ -257,3 +201,71 @@ fn collect_lang_features(path: &Path) -> HashMap<String, Feature> {
         })
         .collect()
 }
+
+pub fn collect_lib_features(base_src_path: &Path,
+                            bad: &mut bool,
+                            features: &HashMap<String, Feature>) -> HashMap<String, Feature> {
+    let mut lib_features = HashMap::<String, Feature>::new();
+    let mut contents = String::new();
+    super::walk(base_src_path,
+                &mut |path| super::filter_dirs(path) || path.ends_with("src/test"),
+                &mut |file| {
+        let filename = file.file_name().unwrap().to_string_lossy();
+        if !filename.ends_with(".rs") || filename == "features.rs" ||
+           filename == "diagnostic_list.rs" {
+            return;
+        }
+
+        contents.truncate(0);
+        t!(t!(File::open(&file), &file).read_to_string(&mut contents));
+
+        for (i, line) in contents.lines().enumerate() {
+            let mut err = |msg: &str| {
+                println!("{}:{}: {}", file.display(), i + 1, msg);
+                *bad = true;
+            };
+            let level = if line.contains("[unstable(") {
+                Status::Unstable
+            } else if line.contains("[stable(") {
+                Status::Stable
+            } else {
+                continue;
+            };
+            let feature_name = match find_attr_val(line, "feature") {
+                Some(name) => name,
+                None => {
+                    err("malformed stability attribute");
+                    continue;
+                }
+            };
+            let since = match find_attr_val(line, "since") {
+                Some(name) => name,
+                None if level == Status::Stable => {
+                    err("malformed stability attribute");
+                    continue;
+                }
+                None => "None",
+            };
+
+            if features.contains_key(feature_name) {
+                err("duplicating a lang feature");
+            }
+            if let Some(ref s) = lib_features.get(feature_name) {
+                if s.level != level {
+                    err("different stability level than before");
+                }
+                if s.since != since {
+                    err("different `since` than before");
+                }
+                continue;
+            }
+            lib_features.insert(feature_name.to_owned(),
+                                Feature {
+                                    level: level,
+                                    since: since.to_owned(),
+                                    has_gate_test: false,
+                                });
+        }
+    });
+    lib_features
+}

src/doc/unstable-book/src/str-checked-slicing.md

@@ -14,6 +14,8 @@
 //! etc. This is run by default on `make check` and as part of the auto
 //! builders.
 
+extern crate regex;
+
 use std::fs;
 use std::path::{PathBuf, Path};
 use std::env;
@@ -37,6 +39,7 @@ mod features;
 mod cargo;
 mod pal;
 mod deps;
+mod unstable_book;
 
 fn main() {
     let path = env::args_os().skip(1).next().expect("need an argument");
@@ -51,6 +54,7 @@ fn main() {
     cargo::check(&path, &mut bad);
     features::check(&path, &mut bad);
     pal::check(&path, &mut bad);
+    unstable_book::check(&path, &mut bad);
     if !args.iter().any(|s| *s == "--no-vendor") {
         deps::check(&path, &mut bad);
     }