Rollup merge of #130931 - GuillaumeGomez:standalone-crate, r=notriddle

Rename `standalone` doctest attribute into `standalone_crate`

Following [zulip discussion](https://rust-lang.zulipchat.com/#narrow/stream/266220-t-rustdoc/topic/Renaming.20code.20block.20.22standalone.22.20attribute.3F) and poll results.

r? `@notriddle`

Author: matthiaskrgr

Diff for: library/core/src/panic/location.rs

@@ -44,7 +44,7 @@ impl<'a> Location<'a> {
     ///
     /// # Examples
     ///
-    /// ```standalone
+    /// ```standalone_crate
     /// use std::panic::Location;
     ///
     /// /// Returns the [`Location`] at which it is called.

Diff for: src/doc/rustdoc/src/write-documentation/documentation-tests.md

@@ -414,11 +414,11 @@ In some cases, doctests cannot be merged. For example, if you have:
 The problem with this code is that, if you change any other doctests, it'll likely break when
 runing `rustdoc --test`, making it tricky to maintain.
 
-This is where the `standalone` attribute comes in: it tells `rustdoc` that a doctest
+This is where the `standalone_crate` attribute comes in: it tells `rustdoc` that a doctest
 should not be merged with the others. So the previous code should use it:
 
 ```rust
-//! ```standalone
+//! ```standalone_crate
 //! let location = std::panic::Location::caller();
 //! assert_eq!(location.line(), 4);
 //! ```

Diff for: src/librustdoc/doctest.rs

@@ -837,7 +837,7 @@ impl CreateRunnableDocTests {
         let is_standalone = !doctest.can_be_merged
             || scraped_test.langstr.compile_fail
             || scraped_test.langstr.test_harness
-            || scraped_test.langstr.standalone
+            || scraped_test.langstr.standalone_crate
             || self.rustdoc_options.nocapture
             || self.rustdoc_options.test_args.iter().any(|arg| arg == "--show-output");
         if is_standalone {

Diff for: src/librustdoc/doctest/make.rs

@@ -48,7 +48,7 @@ impl DocTestBuilder {
     ) -> Self {
         let can_merge_doctests = can_merge_doctests
             && lang_str.is_some_and(|lang_str| {
-                !lang_str.compile_fail && !lang_str.test_harness && !lang_str.standalone
+                !lang_str.compile_fail && !lang_str.test_harness && !lang_str.standalone_crate
             });
 
         let SourceInfo { crate_attrs, maybe_crate_attrs, crates, everything_else } =

Diff for: src/librustdoc/html/markdown.rs

@@ -871,7 +871,7 @@ pub(crate) struct LangString {
     pub(crate) rust: bool,
     pub(crate) test_harness: bool,
     pub(crate) compile_fail: bool,
-    pub(crate) standalone: bool,
+    pub(crate) standalone_crate: bool,
     pub(crate) error_codes: Vec<String>,
     pub(crate) edition: Option<Edition>,
     pub(crate) added_classes: Vec<String>,
@@ -1194,7 +1194,7 @@ impl Default for LangString {
             rust: true,
             test_harness: false,
             compile_fail: false,
-            standalone: false,
+            standalone_crate: false,
             error_codes: Vec::new(),
             edition: None,
             added_classes: Vec::new(),
@@ -1264,8 +1264,8 @@ impl LangString {
                         seen_rust_tags = !seen_other_tags || seen_rust_tags;
                         data.no_run = true;
                     }
-                    LangStringToken::LangToken("standalone") => {
-                        data.standalone = true;
+                    LangStringToken::LangToken("standalone_crate") => {
+                        data.standalone_crate = true;
                         seen_rust_tags = !seen_other_tags || seen_rust_tags;
                     }
                     LangStringToken::LangToken(x) if x.starts_with("edition") => {
@@ -1298,44 +1298,47 @@ impl LangString {
                     }
                     LangStringToken::LangToken(x) if extra.is_some() => {
                         let s = x.to_lowercase();
-                        if let Some((flag, help)) = if s == "compile-fail"
-                            || s == "compile_fail"
-                            || s == "compilefail"
-                        {
-                            Some((
-                                "compile_fail",
-                                "the code block will either not be tested if not marked as a rust one \
-                                 or won't fail if it compiles successfully",
-                            ))
-                        } else if s == "should-panic" || s == "should_panic" || s == "shouldpanic" {
-                            Some((
-                                "should_panic",
-                                "the code block will either not be tested if not marked as a rust one \
-                                 or won't fail if it doesn't panic when running",
-                            ))
-                        } else if s == "no-run" || s == "no_run" || s == "norun" {
-                            Some((
-                                "no_run",
-                                "the code block will either not be tested if not marked as a rust one \
-                                 or will be run (which you might not want)",
-                            ))
-                        } else if s == "test-harness" || s == "test_harness" || s == "testharness" {
-                            Some((
-                                "test_harness",
-                                "the code block will either not be tested if not marked as a rust one \
-                                 or the code will be wrapped inside a main function",
-                            ))
-                        } else {
-                            None
+                        if let Some(help) = match s.as_str() {
+                            "compile-fail" | "compile_fail" | "compilefail" => Some(
+                                "use `compile_fail` to invert the results of this test, so that it \
+                                passes if it cannot be compiled and fails if it can",
+                            ),
+                            "should-panic" | "should_panic" | "shouldpanic" => Some(
+                                "use `should_panic` to invert the results of this test, so that if \
+                                passes if it panics and fails if it does not",
+                            ),
+                            "no-run" | "no_run" | "norun" => Some(
+                                "use `no_run` to compile, but not run, the code sample during \
+                                testing",
+                            ),
+                            "test-harness" | "test_harness" | "testharness" => Some(
+                                "use `test_harness` to run functions marked `#[test]` instead of a \
+                                potentially-implicit `main` function",
+                            ),
+                            "standalone" | "standalone_crate" | "standalone-crate" => {
+                                if let Some(extra) = extra
+                                    && extra.sp.at_least_rust_2024()
+                                {
+                                    Some(
+                                        "use `standalone_crate` to compile this code block \
+                                        separately",
+                                    )
+                                } else {
+                                    None
+                                }
+                            }
+                            _ => None,
                         } {
                             if let Some(extra) = extra {
                                 extra.error_invalid_codeblock_attr_with_help(
                                     format!("unknown attribute `{x}`"),
                                     |lint| {
-                                        lint.help(format!(
-                                            "there is an attribute with a similar name: `{flag}`"
-                                        ))
-                                        .help(help);
+                                        lint.help(help).help(
+                                            "this code block may be skipped during testing, \
+                                            because unknown attributes are treated as markers for \
+                                            code samples written in other programming languages, \
+                                            unless it is also explicitly marked as `rust`",
+                                        );
                                     },
                                 );
                             }

Diff for: tests/run-make/doctests-merge/doctest-standalone.rs

@@ -1,11 +1,11 @@
 #![crate_name = "foo"]
 #![crate_type = "lib"]
 
-//! ```standalone
+//! ```standalone_crate
 //! foo::init();
 //! ```
 
-/// ```standalone
+/// ```standalone_crate
 /// foo::init();
 /// ```
 pub fn init() {

Diff for: tests/rustdoc-ui/doctest/check-attr-test.stderr

@@ -8,8 +8,8 @@ error: unknown attribute `compile-fail`
 9 | | /// ```
   | |_______^
   |
-  = help: there is an attribute with a similar name: `compile_fail`
-  = help: the code block will either not be tested if not marked as a rust one or won't fail if it compiles successfully
+  = help: use `compile_fail` to invert the results of this test, so that it passes if it cannot be compiled and fails if it can
+  = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 note: the lint level is defined here
  --> $DIR/check-attr-test.rs:3:9
   |
@@ -26,8 +26,8 @@ error: unknown attribute `compilefail`
 9 | | /// ```
   | |_______^
   |
-  = help: there is an attribute with a similar name: `compile_fail`
-  = help: the code block will either not be tested if not marked as a rust one or won't fail if it compiles successfully
+  = help: use `compile_fail` to invert the results of this test, so that it passes if it cannot be compiled and fails if it can
+  = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `comPile_fail`
  --> $DIR/check-attr-test.rs:5:1
@@ -39,8 +39,8 @@ error: unknown attribute `comPile_fail`
 9 | | /// ```
   | |_______^
   |
-  = help: there is an attribute with a similar name: `compile_fail`
-  = help: the code block will either not be tested if not marked as a rust one or won't fail if it compiles successfully
+  = help: use `compile_fail` to invert the results of this test, so that it passes if it cannot be compiled and fails if it can
+  = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `should-panic`
   --> $DIR/check-attr-test.rs:12:1
@@ -52,8 +52,8 @@ error: unknown attribute `should-panic`
 16 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `should_panic`
-   = help: the code block will either not be tested if not marked as a rust one or won't fail if it doesn't panic when running
+   = help: use `should_panic` to invert the results of this test, so that if passes if it panics and fails if it does not
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `shouldpanic`
   --> $DIR/check-attr-test.rs:12:1
@@ -65,8 +65,8 @@ error: unknown attribute `shouldpanic`
 16 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `should_panic`
-   = help: the code block will either not be tested if not marked as a rust one or won't fail if it doesn't panic when running
+   = help: use `should_panic` to invert the results of this test, so that if passes if it panics and fails if it does not
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `shOuld_panic`
   --> $DIR/check-attr-test.rs:12:1
@@ -78,8 +78,8 @@ error: unknown attribute `shOuld_panic`
 16 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `should_panic`
-   = help: the code block will either not be tested if not marked as a rust one or won't fail if it doesn't panic when running
+   = help: use `should_panic` to invert the results of this test, so that if passes if it panics and fails if it does not
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `no-run`
   --> $DIR/check-attr-test.rs:19:1
@@ -91,8 +91,8 @@ error: unknown attribute `no-run`
 23 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `no_run`
-   = help: the code block will either not be tested if not marked as a rust one or will be run (which you might not want)
+   = help: use `no_run` to compile, but not run, the code sample during testing
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `norun`
   --> $DIR/check-attr-test.rs:19:1
@@ -104,8 +104,8 @@ error: unknown attribute `norun`
 23 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `no_run`
-   = help: the code block will either not be tested if not marked as a rust one or will be run (which you might not want)
+   = help: use `no_run` to compile, but not run, the code sample during testing
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `nO_run`
   --> $DIR/check-attr-test.rs:19:1
@@ -117,8 +117,8 @@ error: unknown attribute `nO_run`
 23 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `no_run`
-   = help: the code block will either not be tested if not marked as a rust one or will be run (which you might not want)
+   = help: use `no_run` to compile, but not run, the code sample during testing
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `test-harness`
   --> $DIR/check-attr-test.rs:26:1
@@ -130,8 +130,8 @@ error: unknown attribute `test-harness`
 30 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `test_harness`
-   = help: the code block will either not be tested if not marked as a rust one or the code will be wrapped inside a main function
+   = help: use `test_harness` to run functions marked `#[test]` instead of a potentially-implicit `main` function
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `testharness`
   --> $DIR/check-attr-test.rs:26:1
@@ -143,8 +143,8 @@ error: unknown attribute `testharness`
 30 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `test_harness`
-   = help: the code block will either not be tested if not marked as a rust one or the code will be wrapped inside a main function
+   = help: use `test_harness` to run functions marked `#[test]` instead of a potentially-implicit `main` function
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: unknown attribute `tesT_harness`
   --> $DIR/check-attr-test.rs:26:1
@@ -156,8 +156,8 @@ error: unknown attribute `tesT_harness`
 30 | | /// ```
    | |_______^
    |
-   = help: there is an attribute with a similar name: `test_harness`
-   = help: the code block will either not be tested if not marked as a rust one or the code will be wrapped inside a main function
+   = help: use `test_harness` to run functions marked `#[test]` instead of a potentially-implicit `main` function
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
 
 error: aborting due to 12 previous errors
 

Diff for: tests/rustdoc-ui/doctest/standalone-warning-2024.rs

@@ -0,0 +1,16 @@
+// This test checks that it will output warnings for usage of `standalone` or `standalone_crate`.
+
+//@ compile-flags:--test -Zunstable-options --edition 2024
+//@ normalize-stdout-test: "tests/rustdoc-ui/doctest" -> "$$DIR"
+//@ normalize-stdout-test: "finished in \d+\.\d+s" -> "finished in $$TIME"
+//@ normalize-stdout-test: ".rs:\d+:\d+" -> ".rs:$$LINE:$$COL"
+
+#![deny(warnings)]
+
+//! ```standalone
+//! bla
+//! ```
+//!
+//! ```standalone-crate
+//! bla
+//! ```

Diff for: tests/rustdoc-ui/doctest/standalone-warning-2024.stderr

@@ -0,0 +1,38 @@
+error: unknown attribute `standalone`
+  --> $DIR/standalone-warning-2024.rs:10:1
+   |
+10 | / //! ```standalone
+11 | | //! bla
+12 | | //! ```
+13 | | //!
+14 | | //! ```standalone-crate
+15 | | //! bla
+16 | | //! ```
+   | |_______^
+   |
+   = help: use `standalone_crate` to compile this code block separately
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
+note: the lint level is defined here
+  --> $DIR/standalone-warning-2024.rs:8:9
+   |
+8  | #![deny(warnings)]
+   |         ^^^^^^^^
+   = note: `#[deny(rustdoc::invalid_codeblock_attributes)]` implied by `#[deny(warnings)]`
+
+error: unknown attribute `standalone-crate`
+  --> $DIR/standalone-warning-2024.rs:10:1
+   |
+10 | / //! ```standalone
+11 | | //! bla
+12 | | //! ```
+13 | | //!
+14 | | //! ```standalone-crate
+15 | | //! bla
+16 | | //! ```
+   | |_______^
+   |
+   = help: use `standalone_crate` to compile this code block separately
+   = help: this code block may be skipped during testing, because unknown attributes are treated as markers for code samples written in other programming languages, unless it is also explicitly marked as `rust`
+
+error: aborting due to 2 previous errors
+

Diff for: tests/rustdoc-ui/doctest/standalone-warning.rs

@@ -0,0 +1,10 @@
+// This test checks that it will not output warning for usage of `standalone` or `standalone_crate`.
+//@ check-pass
+
+//! ```standalone
+//! bla
+//! ```
+//!
+//! ```standalone-crate
+//! bla
+//! ```