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"

Author: tshepang

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;
 
@@ -36,16 +37,7 @@ 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*-->",
-    )
-    .unwrap()
+    Regex::new(r"[aA]s of (\w+) (\d{4})").unwrap()
 }
 
 fn collect_dates_from_file(date_regex: &Regex, text: &str) -> Vec<(usize, Date)> {
@@ -57,8 +49,8 @@ fn collect_dates_from_file(date_regex: &Regex, text: &str) -> Vec<(usize, Date)>
             (
                 cap.get(0).unwrap().range(),
                 Date {
-                    year: cap["y"].parse().unwrap(),
-                    month: cap["m"].parse().unwrap(),
+                    year: cap[2].parse().unwrap(),
+                    month: Month::from_str(&cap[1]).unwrap().number_from_month(),
                 },
             )
         })
@@ -183,20 +175,18 @@ mod tests {
     #[test]
     fn test_date_regex() {
         let regex = make_date_regex();
-        assert!(regex.is_match("foo <!-- date: 2021-01 --> bar"));
-    }
-
-    #[test]
-    fn test_date_regex_capitalized() {
-        let regex = make_date_regex();
-        assert!(regex.is_match("foo <!-- Date: 2021-08 --> bar"));
+        assert!(regex.is_match("As of July 2022"));
+        assert!(regex.is_match("As of Jul 2022"));
+        assert!(regex.is_match("As of july 2022"));
+        assert!(regex.is_match("As of jul 2022"));
+        assert!(regex.is_match("as of jul 2022"));
     }
 
     #[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 = "Test1\nAs of Jan 2021\nTest2\nAs of Feb 2021 \
+                    \nTest3\nTest4\nAs of march 2021Bar\nas of apr 2021 \
+                    \nTest5\nTest6\nTest7\n\n\nas of may 2021\nTest8
         ";
         assert_eq!(
             collect_dates_from_file(&make_date_regex(), text),

src/backend/backend-agnostic.md

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

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 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/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 <!-- as of 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 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 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 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 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 February 2022) a [bug][#77620] if you use
 worktrees, submodules, and `x.py` in a commit hook. If you run into an error
 like:
 

src/llvm-coverage-instrumentation.md

@@ -222,8 +222,8 @@ properly-configured variables in LLVM IR, according to very specific
 details of the [_LLVM Coverage Mapping Format_][coverage-mapping-format]
 (Version 6).[^llvm-and-covmap-versions]
 
-[^llvm-and-covmap-versions]: The Rust compiler (as of <!-- date: 2021-12 -->
-December 2021) supports _LLVM Coverage Mapping Format_ Version 5 or 6. Version 5
+[^llvm-and-covmap-versions]: The Rust compiler (as of December 2021)
+supports _LLVM Coverage Mapping Format_ Version 5 or 6. Version 5
 was introduced in _LLVM 12_, which is (as of this writing) the minimum LLVM
 version supported by the current version of Rust. Version 6 was introduced in
 _LLVM 13_, which is currently the default LLVM version for Rust. The Rust