Rollup merge of rust-lang#140560 - Urgau:test_attr-module-level, r=GuillaumeGomez

Allow `#![doc(test(attr(..)))]` everywhere

This PR adds the ability to specify [`#![doc(test(attr(..)))]`](https://doc.rust-lang.org/nightly/rustdoc/write-documentation/the-doc-attribute.html#testattr) ~~at module level~~ everywhere in addition to allowing it at crate-root.

This is motivated by a recent PR rust-lang#140323 (by ```@tgross35)``` where we have to duplicate 2 attributes to every single `f16` and `f128` doctests, by allowing `#![doc(test(attr(..)))]` at module level (and everywhere else) we can omit them entirely and just have (in both module):

```rust
#![doc(test(attr(feature(cfg_target_has_reliable_f16_f128))))]
#![doc(test(attr(expect(internal_features))))]
```

Those new attributes are appended to the one found at crate-root or at a previous module. Those "global" attributes are compatible with merged doctests (they already were before).

Given the small addition that this is, I'm proposing to insta-stabilize it, but I can feature-gate it if preferred.

Best reviewed commit by commit.

r? ```@GuillaumeGomez```

Author: GuillaumeGomez

compiler/rustc_passes/src/check_attr.rs

@@ -1266,13 +1266,17 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         true
     }
 
-    /// Checks that `doc(test(...))` attribute contains only valid attributes. Returns `true` if
-    /// valid.
-    fn check_test_attr(&self, meta: &MetaItemInner, hir_id: HirId) {
+    /// Checks that `doc(test(...))` attribute contains only valid attributes and are at the right place.
+    fn check_test_attr(&self, attr: &Attribute, meta: &MetaItemInner, hir_id: HirId) {
         if let Some(metas) = meta.meta_item_list() {
             for i_meta in metas {
                 match (i_meta.name(), i_meta.meta_item()) {
-                    (Some(sym::attr | sym::no_crate_inject), _) => {}
+                    (Some(sym::attr), _) => {
+                        // Allowed everywhere like `#[doc]`
+                    }
+                    (Some(sym::no_crate_inject), _) => {
+                        self.check_attr_crate_level(attr, meta, hir_id);
+                    }
                     (_, Some(m)) => {
                         self.tcx.emit_node_span_lint(
                             INVALID_DOC_ATTRIBUTES,
@@ -1359,9 +1363,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                         }
 
                         Some(sym::test) => {
-                            if self.check_attr_crate_level(attr, meta, hir_id) {
-                                self.check_test_attr(meta, hir_id);
-                            }
+                            self.check_test_attr(attr, meta, hir_id);
                         }
 
                         Some(

src/doc/rustdoc/src/write-documentation/the-doc-attribute.md

@@ -143,15 +143,6 @@ But if you include this:
 
 it will not.
 
-### `test(attr(...))`
-
-This form of the `doc` attribute allows you to add arbitrary attributes to all your doctests. For
-example, if you want your doctests to fail if they have dead code, you could add this:
-
-```rust,no_run
-#![doc(test(attr(deny(dead_code))))]
-```
-
 ## At the item level
 
 These forms of the `#[doc]` attribute are used on individual items, to control how
@@ -283,3 +274,26 @@ To get around this limitation, we just add `#[doc(alias = "lib_name_do_something
 on the `do_something` method and then it's all good!
 Users can now look for `lib_name_do_something` in our crate directly and find
 `Obj::do_something`.
+
+### `test(attr(...))`
+
+This form of the `doc` attribute allows you to add arbitrary attributes to all your doctests. For
+example, if you want your doctests to fail if they have dead code, you could add this:
+
+```rust,no_run
+#![doc(test(attr(deny(dead_code))))]
+
+mod my_mod {
+    #![doc(test(attr(allow(dead_code))))] // but allow `dead_code` for this module
+}
+```
+
+`test(attr(..))` attributes are appended to the parent module's, they do not replace the current
+list of attributes. In the previous example, both attributes would be present:
+
+```rust,no_run
+// For every doctest in `my_mod`
+
+#![deny(dead_code)] // from the crate-root
+#![allow(dead_code)] // from `my_mod`
+```

src/librustdoc/doctest.rs

@@ -5,6 +5,7 @@ mod runner;
 mod rust;
 
 use std::fs::File;
+use std::hash::{Hash, Hasher};
 use std::io::{self, Write};
 use std::path::{Path, PathBuf};
 use std::process::{self, Command, Stdio};
@@ -14,7 +15,7 @@ use std::{panic, str};
 
 pub(crate) use make::{BuildDocTestBuilder, DocTestBuilder};
 pub(crate) use markdown::test as test_markdown;
-use rustc_data_structures::fx::{FxHashMap, FxIndexMap, FxIndexSet};
+use rustc_data_structures::fx::{FxHashMap, FxHasher, FxIndexMap, FxIndexSet};
 use rustc_errors::emitter::HumanReadableErrorType;
 use rustc_errors::{ColorConfig, DiagCtxtHandle};
 use rustc_hir as hir;
@@ -45,8 +46,6 @@ pub(crate) struct GlobalTestOptions {
     /// Whether inserting extra indent spaces in code block,
     /// default is `false`, only `true` for generating code link of Rust playground
     pub(crate) insert_indent_space: bool,
-    /// Additional crate-level attributes to add to doctests.
-    pub(crate) attrs: Vec<String>,
     /// Path to file containing arguments for the invocation of rustc.
     pub(crate) args_file: PathBuf,
 }
@@ -283,7 +282,7 @@ pub(crate) fn run_tests(
     rustdoc_options: &Arc<RustdocOptions>,
     unused_extern_reports: &Arc<Mutex<Vec<UnusedExterns>>>,
     mut standalone_tests: Vec<test::TestDescAndFn>,
-    mergeable_tests: FxIndexMap<Edition, Vec<(DocTestBuilder, ScrapedDocTest)>>,
+    mergeable_tests: FxIndexMap<MergeableTestKey, Vec<(DocTestBuilder, ScrapedDocTest)>>,
     // We pass this argument so we can drop it manually before using `exit`.
     mut temp_dir: Option<TempDir>,
 ) {
@@ -298,7 +297,7 @@ pub(crate) fn run_tests(
     let mut ran_edition_tests = 0;
     let target_str = rustdoc_options.target.to_string();
 
-    for (edition, mut doctests) in mergeable_tests {
+    for (MergeableTestKey { edition, global_crate_attrs_hash }, mut doctests) in mergeable_tests {
         if doctests.is_empty() {
             continue;
         }
@@ -308,8 +307,8 @@ pub(crate) fn run_tests(
 
         let rustdoc_test_options = IndividualTestOptions::new(
             rustdoc_options,
-            &Some(format!("merged_doctest_{edition}")),
-            PathBuf::from(format!("doctest_{edition}.rs")),
+            &Some(format!("merged_doctest_{edition}_{global_crate_attrs_hash}")),
+            PathBuf::from(format!("doctest_{edition}_{global_crate_attrs_hash}.rs")),
         );
 
         for (doctest, scraped_test) in &doctests {
@@ -371,12 +370,9 @@ fn scrape_test_config(
     attrs: &[hir::Attribute],
     args_file: PathBuf,
 ) -> GlobalTestOptions {
-    use rustc_ast_pretty::pprust;
-
     let mut opts = GlobalTestOptions {
         crate_name,
         no_crate_inject: false,
-        attrs: Vec::new(),
         insert_indent_space: false,
         args_file,
     };
@@ -393,13 +389,7 @@ fn scrape_test_config(
         if attr.has_name(sym::no_crate_inject) {
             opts.no_crate_inject = true;
         }
-        if attr.has_name(sym::attr)
-            && let Some(l) = attr.meta_item_list()
-        {
-            for item in l {
-                opts.attrs.push(pprust::meta_list_item_to_string(item));
-            }
-        }
+        // NOTE: `test(attr(..))` is handled when discovering the individual tests
     }
 
     opts
@@ -848,6 +838,7 @@ pub(crate) struct ScrapedDocTest {
     text: String,
     name: String,
     span: Span,
+    global_crate_attrs: Vec<String>,
 }
 
 impl ScrapedDocTest {
@@ -858,6 +849,7 @@ impl ScrapedDocTest {
         langstr: LangString,
         text: String,
         span: Span,
+        global_crate_attrs: Vec<String>,
     ) -> Self {
         let mut item_path = logical_path.join("::");
         item_path.retain(|c| c != ' ');
@@ -867,7 +859,7 @@ impl ScrapedDocTest {
         let name =
             format!("{} - {item_path}(line {line})", filename.prefer_remapped_unconditionaly());
 
-        Self { filename, line, langstr, text, name, span }
+        Self { filename, line, langstr, text, name, span, global_crate_attrs }
     }
     fn edition(&self, opts: &RustdocOptions) -> Edition {
         self.langstr.edition.unwrap_or(opts.edition)
@@ -896,9 +888,15 @@ pub(crate) trait DocTestVisitor {
     fn visit_header(&mut self, _name: &str, _level: u32) {}
 }
 
+#[derive(Clone, Debug, Hash, Eq, PartialEq)]
+pub(crate) struct MergeableTestKey {
+    edition: Edition,
+    global_crate_attrs_hash: u64,
+}
+
 struct CreateRunnableDocTests {
     standalone_tests: Vec<test::TestDescAndFn>,
-    mergeable_tests: FxIndexMap<Edition, Vec<(DocTestBuilder, ScrapedDocTest)>>,
+    mergeable_tests: FxIndexMap<MergeableTestKey, Vec<(DocTestBuilder, ScrapedDocTest)>>,
 
     rustdoc_options: Arc<RustdocOptions>,
     opts: GlobalTestOptions,
@@ -949,6 +947,7 @@ impl CreateRunnableDocTests {
         let edition = scraped_test.edition(&self.rustdoc_options);
         let doctest = BuildDocTestBuilder::new(&scraped_test.text)
             .crate_name(&self.opts.crate_name)
+            .global_crate_attrs(scraped_test.global_crate_attrs.clone())
             .edition(edition)
             .can_merge_doctests(self.can_merge_doctests)
             .test_id(test_id)
@@ -965,7 +964,17 @@ impl CreateRunnableDocTests {
             let test_desc = self.generate_test_desc_and_fn(doctest, scraped_test);
             self.standalone_tests.push(test_desc);
         } else {
-            self.mergeable_tests.entry(edition).or_default().push((doctest, scraped_test));
+            self.mergeable_tests
+                .entry(MergeableTestKey {
+                    edition,
+                    global_crate_attrs_hash: {
+                        let mut hasher = FxHasher::default();
+                        scraped_test.global_crate_attrs.hash(&mut hasher);
+                        hasher.finish()
+                    },
+                })
+                .or_default()
+                .push((doctest, scraped_test));
         }
     }
 

src/librustdoc/doctest/extracted.rs

@@ -35,13 +35,16 @@ impl ExtractedDocTests {
     ) {
         let edition = scraped_test.edition(options);
 
-        let ScrapedDocTest { filename, line, langstr, text, name, .. } = scraped_test;
+        let ScrapedDocTest { filename, line, langstr, text, name, global_crate_attrs, .. } =
+            scraped_test;
 
         let doctest = BuildDocTestBuilder::new(&text)
             .crate_name(&opts.crate_name)
+            .global_crate_attrs(global_crate_attrs)
             .edition(edition)
             .lang_str(&langstr)
             .build(None);
+
         let (full_test_code, size) = doctest.generate_unique_doctest(
             &text,
             langstr.test_harness,

src/librustdoc/doctest/make.rs

@@ -45,6 +45,7 @@ pub(crate) struct BuildDocTestBuilder<'a> {
     test_id: Option<String>,
     lang_str: Option<&'a LangString>,
     span: Span,
+    global_crate_attrs: Vec<String>,
 }
 
 impl<'a> BuildDocTestBuilder<'a> {
@@ -57,6 +58,7 @@ impl<'a> BuildDocTestBuilder<'a> {
             test_id: None,
             lang_str: None,
             span: DUMMY_SP,
+            global_crate_attrs: Vec::new(),
         }
     }
 
@@ -96,6 +98,12 @@ impl<'a> BuildDocTestBuilder<'a> {
         self
     }
 
+    #[inline]
+    pub(crate) fn global_crate_attrs(mut self, global_crate_attrs: Vec<String>) -> Self {
+        self.global_crate_attrs = global_crate_attrs;
+        self
+    }
+
     pub(crate) fn build(self, dcx: Option<DiagCtxtHandle<'_>>) -> DocTestBuilder {
         let BuildDocTestBuilder {
             source,
@@ -106,6 +114,7 @@ impl<'a> BuildDocTestBuilder<'a> {
             test_id,
             lang_str,
             span,
+            global_crate_attrs,
         } = self;
         let can_merge_doctests = can_merge_doctests
             && lang_str.is_some_and(|lang_str| {
@@ -133,6 +142,7 @@ impl<'a> BuildDocTestBuilder<'a> {
             // If the AST returned an error, we don't want this doctest to be merged with the
             // others.
             return DocTestBuilder::invalid(
+                Vec::new(),
                 String::new(),
                 String::new(),
                 String::new(),
@@ -155,6 +165,7 @@ impl<'a> BuildDocTestBuilder<'a> {
         DocTestBuilder {
             supports_color,
             has_main_fn,
+            global_crate_attrs,
             crate_attrs,
             maybe_crate_attrs,
             crates,
@@ -173,6 +184,7 @@ pub(crate) struct DocTestBuilder {
     pub(crate) supports_color: bool,
     pub(crate) already_has_extern_crate: bool,
     pub(crate) has_main_fn: bool,
+    pub(crate) global_crate_attrs: Vec<String>,
     pub(crate) crate_attrs: String,
     /// If this is a merged doctest, it will be put into `everything_else`, otherwise it will
     /// put into `crate_attrs`.
@@ -186,6 +198,7 @@ pub(crate) struct DocTestBuilder {
 
 impl DocTestBuilder {
     fn invalid(
+        global_crate_attrs: Vec<String>,
         crate_attrs: String,
         maybe_crate_attrs: String,
         crates: String,
@@ -195,6 +208,7 @@ impl DocTestBuilder {
         Self {
             supports_color: false,
             has_main_fn: false,
+            global_crate_attrs,
             crate_attrs,
             maybe_crate_attrs,
             crates,
@@ -224,7 +238,8 @@ impl DocTestBuilder {
         let mut line_offset = 0;
         let mut prog = String::new();
         let everything_else = self.everything_else.trim();
-        if opts.attrs.is_empty() {
+
+        if self.global_crate_attrs.is_empty() {
             // If there aren't any attributes supplied by #![doc(test(attr(...)))], then allow some
             // lints that are commonly triggered in doctests. The crate-level test attributes are
             // commonly used to make tests fail in case they trigger warnings, so having this there in
@@ -233,8 +248,8 @@ impl DocTestBuilder {
             line_offset += 1;
         }
 
-        // Next, any attributes that came from the crate root via #![doc(test(attr(...)))].
-        for attr in &opts.attrs {
+        // Next, any attributes that came from #![doc(test(attr(...)))].
+        for attr in &self.global_crate_attrs {
             prog.push_str(&format!("#![{attr}]\n"));
             line_offset += 1;
         }

src/librustdoc/doctest/markdown.rs

@@ -31,6 +31,7 @@ impl DocTestVisitor for MdCollector {
             config,
             test,
             DUMMY_SP,
+            Vec::new(),
         ));
     }
 
@@ -96,7 +97,6 @@ pub(crate) fn test(input: &Input, options: Options) -> Result<(), String> {
         crate_name,
         no_crate_inject: true,
         insert_indent_space: false,
-        attrs: vec![],
         args_file,
     };