Allow #![doc(test(attr(..)))] doctests to be again merged together

Author: Urgau

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::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;
@@ -313,7 +314,7 @@ 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)>>,
 ) {
     let mut test_args = Vec::with_capacity(rustdoc_options.test_args.len() + 1);
     test_args.insert(0, "rustdoctest".to_string());
@@ -326,7 +327,7 @@ 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;
         }
@@ -336,8 +337,8 @@ 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 {
@@ -910,9 +911,15 @@ 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,
@@ -980,7 +987,17 @@ 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/make.rs

@@ -107,9 +107,6 @@ impl DocTestBuilder {
         let can_be_merged = can_merge_doctests
             && !has_global_allocator
             && crate_attrs.is_empty()
-            // FIXME: We can probably merge tests which have the same global crate attrs,
-            // like we already do for the edition
-            && global_crate_attrs.is_empty()
             // If this is a merged doctest and a defined macro uses `$crate`, then the path will
             // not work, so better not put it into merged doctests.
             && !(has_macro_def && everything_else.contains("$crate"));

tests/run-make/doctests-keep-binaries-2024/rmake.rs

@@ -16,7 +16,22 @@ fn setup_test_env<F: FnOnce(&Path, &Path)>(callback: F) {
 }
 
 fn check_generated_binaries() {
-    run("doctests/merged_doctest_2024/rust_out");
+    let mut found_merged_doctest = false;
+    rfs::read_dir_entries("doctests/", |path| {
+        if path
+            .file_name()
+            .and_then(|name| name.to_str())
+            .is_some_and(|name| name.starts_with("merged_doctest_2024"))
+        {
+            found_merged_doctest = true;
+            let rust_out = path.join("rust_out");
+            let rust_out = rust_out.to_string_lossy();
+            run(&*rust_out);
+        }
+    });
+    if !found_merged_doctest {
+        panic!("no directory starting with `merged_doctest_2024` found under `doctests/`");
+    }
 }
 
 fn main() {

tests/rustdoc-ui/doctest/dead-code-module-2.stdout

@@ -1,8 +1,13 @@
 
-running 2 tests
-test $DIR/dead-code-module-2.rs - my_mod::f (line 16) - compile ... FAILED
+running 1 test
 test $DIR/dead-code-module-2.rs - g (line 24) - compile ... ok
 
+test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+
+
+running 1 test
+test $DIR/dead-code-module-2.rs - my_mod::f (line 16) - compile ... FAILED
+
 failures:
 
 ---- $DIR/dead-code-module-2.rs - my_mod::f (line 16) stdout ----
@@ -26,5 +31,5 @@ Couldn't compile the test.
 failures:
     $DIR/dead-code-module-2.rs - my_mod::f (line 16)
 
-test result: FAILED. 1 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME