make date-check more lightweight (rust-lang#1394)

* make date-check lightweight

This avoids having to write the date twice when updating date-check.

Before "As of <-- 2022-07 --> July 2022"
After "As of July 2022"

* please clippy

* update date-check docs

* accept review suggestion

Co-authored-by: Noah Lev <camelidcamel@gmail.com>

* address review comment

rust-lang#1394 (review)

* accept review suggestion

Co-authored-by: Noah Lev <camelidcamel@gmail.com>

* address review comment

rust-lang#1394 (review)

* address review comment

rust-lang#1394 (comment)

* this breaks markdown

* address review comment

rust-lang#1394 (comment)

This led to a more robust regex, though making the tool more picky.
It also found a wrong date format that was missed.

* address review comment

rust-lang#1394 (comment)

* address review comment

rust-lang#1394 (comment)

* accept review suggestion

This was reverted by mistake

Co-authored-by: Noah Lev <camelidcamel@gmail.com>

* address review comment

rust-lang#1394 (comment)

* use a more simple fn

* address review comment

rust-lang#1394 (comment)

Much more clean

* nit

* accept review suggestion

Co-authored-by: Noah Lev <camelidcamel@gmail.com>

* avoid a failed regex

Also, test new shape

* adjust to new regex (which uses named groups)

New regex was introduced by 456008c

Co-authored-by: Noah Lev <camelidcamel@gmail.com>

ci/date-check/src/main.rs

@@ -3,9 +3,10 @@ use std::{
     convert::TryInto as _,
     env, fmt, fs,
     path::{Path, PathBuf},
+    str::FromStr,
 };
 
-use chrono::{Datelike as _, TimeZone as _, Utc};
+use chrono::{Datelike as _, Month, TimeZone as _, Utc};
 use glob::glob;
 use regex::Regex;
 
@@ -38,12 +39,18 @@ impl fmt::Display for Date {
 fn make_date_regex() -> Regex {
     Regex::new(
         r"(?x) # insignificant whitespace mode
-        <!--\s*
-        [dD]ate:\s*
-        (?P<y>\d{4}) # year
-        -
-        (?P<m>\d{2}) # month
-        \s*-->",
+        (<!--\s*
+          date-check:\s*
+          (?P<m1>\D+)\s+
+          (?P<y1>\d{4})\s*-->
+        )
+        |
+        (<!--\s*
+          date-check\s*-->\s+
+          (?P<m2>\D+)\s+
+          (?P<y2>\d{4})\b
+        )
+    ",
     )
     .unwrap()
 }
@@ -52,15 +59,22 @@ fn collect_dates_from_file(date_regex: &Regex, text: &str) -> Vec<(usize, Date)>
     let mut line = 1;
     let mut end_of_last_cap = 0;
     date_regex
-        .captures_iter(&text)
-        .map(|cap| {
-            (
-                cap.get(0).unwrap().range(),
-                Date {
-                    year: cap["y"].parse().unwrap(),
-                    month: cap["m"].parse().unwrap(),
-                },
-            )
+        .captures_iter(text)
+        .filter_map(|cap| {
+            if let (Some(month), Some(year), None, None) | (None, None, Some(month), Some(year)) = (
+                cap.name("m1"),
+                cap.name("y1"),
+                cap.name("m2"),
+                cap.name("y2"),
+            ) {
+                let year = year.as_str().parse().expect("year");
+                let month = Month::from_str(month.as_str())
+                    .expect("month")
+                    .number_from_month();
+                Some((cap.get(0).expect("all").range(), Date { year, month }))
+            } else {
+                None
+            }
         })
         .map(|(byte_range, date)| {
             line += text[end_of_last_cap..byte_range.end]
@@ -182,61 +196,153 @@ mod tests {
 
     #[test]
     fn test_date_regex() {
-        let regex = make_date_regex();
-        assert!(regex.is_match("foo <!-- date: 2021-01 --> bar"));
+        let regex = &make_date_regex();
+        assert!(regex.is_match("<!-- date-check: jan 2021 -->"));
+        assert!(regex.is_match("<!-- date-check: january 2021 -->"));
+        assert!(regex.is_match("<!-- date-check: Jan 2021 -->"));
+        assert!(regex.is_match("<!-- date-check: January 2021 -->"));
+        assert!(regex.is_match("<!-- date-check --> jan 2021"));
+        assert!(regex.is_match("<!-- date-check --> january 2021"));
+        assert!(regex.is_match("<!-- date-check --> Jan 2021"));
+        assert!(regex.is_match("<!-- date-check --> January 2021"));
+
+        assert!(regex.is_match("<!-- date-check --> jan 2021 "));
+        assert!(regex.is_match("<!-- date-check --> jan 2021."));
     }
 
     #[test]
-    fn test_date_regex_capitalized() {
-        let regex = make_date_regex();
-        assert!(regex.is_match("foo <!-- Date: 2021-08 --> bar"));
+    fn test_date_regex_fail() {
+        let regexes = &make_date_regex();
+        assert!(!regexes.is_match("<!-- date-check: jan 221 -->"));
+        assert!(!regexes.is_match("<!-- date-check: jan 20221 -->"));
+        assert!(!regexes.is_match("<!-- date-check: 01 2021 -->"));
+        assert!(!regexes.is_match("<!-- date-check --> jan 221"));
+        assert!(!regexes.is_match("<!-- date-check --> jan 20222"));
+        assert!(!regexes.is_match("<!-- date-check --> 01 2021"));
     }
 
     #[test]
     fn test_collect_dates_from_file() {
-        let text = "Test1\n<!-- date: 2021-01 -->\nTest2\nFoo<!-- date: 2021-02 \
-                    -->\nTest3\nTest4\nFoo<!-- date: 2021-03 -->Bar\n<!-- date: 2021-04 \
-                    -->\nTest5\nTest6\nTest7\n<!-- date: \n\n2021-05 -->\nTest8
+        let text = r"
+Test1
+<!-- date-check: jan 2021 -->
+Test2
+Foo<!-- date-check: february 2021
+-->
+Test3
+Test4
+Foo<!-- date-check: Mar 2021 -->Bar
+<!-- date-check:April 2021
+-->
+Test5
+Test6
+Test7
+<!-- date-check:
+
+may 2021 -->
+Test8
+Test1
+<!-- date-check -->  jan 2021
+Test2
+Foo<!-- date-check
+--> february 2021
+Test3
+Test4
+Foo<!-- date-check -->  mar 2021 Bar
+<!-- date-check
+--> apr 2021
+Test5
+Test6
+Test7
+<!-- date-check
+
+ --> may 2021
+Test8
+ <!--
+   date-check
+ --> june 2021.
         ";
         assert_eq!(
             collect_dates_from_file(&make_date_regex(), text),
             vec![
                 (
-                    2,
+                    3,
                     Date {
                         year: 2021,
                         month: 1,
                     }
                 ),
                 (
-                    4,
+                    6,
                     Date {
                         year: 2021,
                         month: 2,
                     }
                 ),
                 (
-                    7,
+                    9,
                     Date {
                         year: 2021,
                         month: 3,
                     }
                 ),
                 (
-                    8,
+                    11,
                     Date {
                         year: 2021,
                         month: 4,
                     }
                 ),
                 (
-                    14,
+                    17,
                     Date {
                         year: 2021,
                         month: 5,
                     }
                 ),
-            ]
+                (
+                    20,
+                    Date {
+                        year: 2021,
+                        month: 1,
+                    }
+                ),
+                (
+                    23,
+                    Date {
+                        year: 2021,
+                        month: 2,
+                    }
+                ),
+                (
+                    26,
+                    Date {
+                        year: 2021,
+                        month: 3,
+                    }
+                ),
+                (
+                    28,
+                    Date {
+                        year: 2021,
+                        month: 4,
+                    }
+                ),
+                (
+                    34,
+                    Date {
+                        year: 2021,
+                        month: 5,
+                    }
+                ),
+                (
+                    38,
+                    Date {
+                        year: 2021,
+                        month: 6,
+                    }
+                ),
+            ],
         );
     }
 }

src/backend/backend-agnostic.md

@@ -2,7 +2,7 @@
 
 <!-- toc -->
 
-As of <!-- date: 2021-10 --> October 2021, `rustc_codegen_ssa` provides an
+As of <!-- date-check --> October 2021, `rustc_codegen_ssa` provides an
 abstract interface for all backends to implement, to allow other codegen
 backends (e.g. [Cranelift]).
 

src/backend/updating-llvm.md

@@ -66,8 +66,8 @@ Example PRs look like:
 
 ## Feature updates
 
-> Note that this information is as of the time of this writing <!-- date:
-2021-10 --> (October 2021). The process for updating LLVM changes with
+> Note that this information is as of the time of this writing, <!--
+date-check --> October 2021. The process for updating LLVM changes with
 practically all LLVM updates, so this may be out of date!
 
 Unlike bugfixes, updating to pick up a new feature of LLVM typically requires a

src/borrow_check/region_inference/member_constraints.md

@@ -94,7 +94,7 @@ member constraints come in.
 ## Choices are always lifetime parameters
 
 At present, the "choice" regions from a member constraint are always lifetime
-parameters from the current function. As of <!-- date: 2021-10 --> October 2021,
+parameters from the current function. As of <!-- date-check --> October 2021,
 this falls out from the placement of impl Trait, though in the future it may not
 be the case. We take some advantage of this fact, as it simplifies the current
 code. In particular, we don't have to consider a case like `'0 member of ['1,

src/building/suggested.md

@@ -22,7 +22,7 @@ You can also install the hook as a step of running `./x.py setup`!
 a file. By default, `rust-analyzer` runs the `cargo check` and `rustfmt`
 commands, but you can override these commands to use more adapted versions
 of these tools when hacking on `rustc`. For example, for Visual Studio Code,
-you can write: <!-- date: 2022-04 --><!-- the date comment is for the edition below -->
+you can write: <!-- date-check: apr 2022 --><!-- the date comment is for the edition below -->
 
 ```JSON
 {

src/contributing.md

@@ -437,17 +437,35 @@ Just a few things to keep in mind:
     the project.
 
   - The date the comment was added, e.g. instead of writing _"Currently, ..."_
-    or _"As of now, ..."_, consider writing
-    _"As of January 2021, ..."_.
-    Try to format the date as `<MONTH> <YEAR>` to ease search.
+    or _"As of now, ..."_,
+    consider adding the date, in one of the following formats:
+    - Jan 2021
+    - January 2021
+    - jan 2021
+    - january 2021
 
-  - Additionally, include a machine-readable comment of the form `<!-- date:
-    2022-04 -->` (if the current month is April 2022). We have an automated
-    tool that uses these (in `ci/date-check`).
+    There is a CI action (in `~/.github/workflows/date-check.yml`)
+    that generates a monthly issue with any of these that are over 6 months old.
 
-    So, for the month of April 2022, the comment would look like: `As of <!--
-    date: 2022-04 --> April 2022`. Make sure to put the comment *between* `as of`
-    and `April 2022`; see [PR #1066][rdg#1066] for the rationale.
+    For the action to pick the date,
+    add a special annotation before specifying the date:
+
+    ```md
+    <!-- date-check --> Jul 2022
+    ```
+
+    Example:
+
+    ```md
+    As of <!-- date-check --> Jul 2022, the foo did the bar.
+    ```
+
+    For cases where the date should not be part of the visible rendered output,
+    use the following instead:
+
+    ```md
+    <!-- date-check: Jul 2022 -->
+    ```
 
   - A link to a relevant WG, tracking issue, `rustc` rustdoc page, or similar, that may provide
     further explanation for the change process or a way to verify that the information is not
@@ -459,7 +477,6 @@ Just a few things to keep in mind:
 
 [rdg]: https://rustc-dev-guide.rust-lang.org/
 [rdgrepo]: https://github.com/rust-lang/rustc-dev-guide
-[rdg#1066]: https://github.com/rust-lang/rustc-dev-guide/pull/1066
 
 ## Issue Triage
 

src/conventions.md

@@ -14,14 +14,14 @@ special config, so this may result in different style from normal [`rustfmt`].
 Therefore, formatting this repository using `cargo fmt` is not recommended.
 
 Instead, formatting should be done using `./x.py fmt`. It's a good habit to run
-`./x.py fmt` before every commit, as this reduces conflicts later. 
+`./x.py fmt` before every commit, as this reduces conflicts later.
 
 Formatting is checked by the `tidy` script. It runs automatically when you do
 `./x.py test` and can be run in isolation with `./x.py fmt --check`.
 
 If you want to use format-on-save in your editor, the pinned version of
 `rustfmt` is built under `build/<target>/stage0/bin/rustfmt`. You'll have to
-pass the <!-- date: 2022-04 --> `--edition=2021` argument yourself when calling
+pass the <!-- date-check: April 2022 --> `--edition=2021` argument yourself when calling
 `rustfmt` directly.
 
 [fmt]: https://github.com/rust-dev-tools/fmt-rfcs

src/crates-io.md

@@ -12,7 +12,7 @@ reasons:
 - The dependency may have transitive dependencies that have one of the above
   problems.
 
-As of <!-- date: 2022-02 --> February 2022, there is no official policy for vetting
+As of <!-- date-check --> February 2022, there is no official policy for vetting
 new dependencies to the compiler. Generally, new dependencies are not added
 to the compiler unless there is a good reason to do so.
 

src/diagnostics/diagnostic-items.md

@@ -43,7 +43,7 @@ A new diagnostic item can be added with these two steps:
     For the naming conventions of diagnostic items, please refer to
     [*Naming Conventions*](#naming-conventions).
 
-2. As of <!-- date: 2022-02 --> February 2022, diagnostic items in code are
+2. As of <!-- date-check --> February 2022, diagnostic items in code are
    accessed via symbols in [`rustc_span::symbol::sym`]. To add your newly
    created diagnostic item simply open the module file and add the name (In
    this case `Cat`) at the correct point in the list.

src/diagnostics/lintstore.md

@@ -17,7 +17,7 @@ default lint level and other metadata come from. These are normally defined by
 way of the [`declare_lint!`] macro, which boils down to a static with type
 `&rustc_session::lint::Lint`.
 
-As of <!-- date: 2022-02 --> February 2022, we lint against direct declarations
+As of <!-- date-check --> February 2022, we lint against direct declarations
 without the use of the macro today (although this may change in the future, as
 the macro is somewhat unwieldy to add new fields to, like all macros).
 

src/diagnostics/translation.md

@@ -217,7 +217,7 @@ returned by `Emitter::fluent_bundle`. This bundle is used preferentially when
 translating messages, the fallback bundle is only used if the primary bundle is
 missing a message or not provided.
 
-As of <!-- date: 2022-06 --> June 2022, there are no locale bundles
+As of <!-- date-check --> June 2022, there are no locale bundles
 distributed with the compiler, but mechanisms are implemented for loading
 bundles.
 

src/git.md

@@ -157,7 +157,7 @@ no changes added to commit (use "git add" and/or "git commit -a")
 These changes are not changes to files: they are changes to submodules (more on
 this [later](#git-submodules)). To get rid of those, run `git submodule update`
 (or run any `x.py` command, which will automatically update the submodules).
-Note that there is (as of <!-- date: 2022-02 --> February 2022) a [bug][#77620] if you use
+Note that there is (as of <!-- date-check --> February 2022) a [bug][#77620] if you use
 worktrees, submodules, and `x.py` in a commit hook. If you run into an error
 like: