From c7e80be1779ad665435ed40cf910aa70a7f2fbdf Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume.gomez@huawei.com>
Date: Wed, 17 Apr 2024 16:03:55 +0200
Subject: [PATCH] Improve handling of `--persist-doctests` with combined
 doctests and update associated test to check both combined and non-combined
 doctests

---
 src/librustdoc/doctest.rs                     | 29 ++++++++++++++-----
 .../run-make/doctests-keep-binaries/Makefile  |  8 ++---
 tests/run-make/doctests-keep-binaries/t.rs    |  8 +++++
 3 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index a1d93e5a0ee6e..dd157cd8c59cd 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -318,6 +318,7 @@ enum TestFailure {
     UnexpectedRunPass,
 }
 
+#[derive(Debug)]
 enum DirState {
     Temp(tempfile::TempDir),
     Perm(PathBuf),
@@ -383,10 +384,26 @@ fn run_test(
     edition: Edition,
     report_unused_externs: impl Fn(UnusedExterns),
     no_run: bool,
+    // Used to prevent overwriting a binary in case `--persist-doctests` is used.
+    binary_extra: Option<&str>,
 ) -> Result<(), TestFailure> {
     // Make sure we emit well-formed executable names for our target.
-    let rust_out = add_exe_suffix("rust_out".to_owned(), &rustdoc_options.target);
-    let output_file = outdir.path().join(rust_out);
+    let rust_out =
+        add_exe_suffix(format!("rust_out{}", binary_extra.unwrap_or("")), &rustdoc_options.target);
+    let out_dir = outdir.path();
+    let out_dir = if is_multiple_tests {
+        // If this a "multiple tests" case, we want to put it into the parent instead.
+        out_dir.parent().unwrap_or(out_dir)
+    } else {
+        out_dir
+    };
+    if matches!(*outdir, DirState::Perm(..)) {
+        if let Err(err) = std::fs::create_dir_all(&out_dir) {
+            eprintln!("Couldn't create directory for doctest executables: {err}");
+            panic::resume_unwind(Box::new(()));
+        }
+    }
+    let output_file = out_dir.join(rust_out);
 
     let rustc_binary = rustdoc_options
         .test_builder
@@ -753,6 +770,7 @@ impl DocTest {
                     edition,
                     report_unused_externs,
                     no_run,
+                    None,
                 );
 
                 if let Err(err) = res {
@@ -897,11 +915,6 @@ pub(crate) fn make_test(
         let mut path = path.clone();
         path.push(&test_id);
 
-        if let Err(err) = std::fs::create_dir_all(&path) {
-            eprintln!("Couldn't create directory for doctest executables: {err}");
-            panic::resume_unwind(Box::new(()));
-        }
-
         DirState::Perm(path)
     } else {
         DirState::Temp(get_doctest_dir().expect("rustdoc needs a tempdir"))
@@ -1390,6 +1403,8 @@ test::test_main(&[{test_args}], vec![{ids}], None);
             self.edition,
             |_: UnusedExterns| {},
             false,
+            // To prevent writing over an existing doctest
+            Some(&format!("_{}_{}", self.edition, *self.ran_edition_tests)),
         );
         if let Err(TestFailure::CompileError) = ret {
             // We failed to compile all compatible tests as one so we push them into the
diff --git a/tests/run-make/doctests-keep-binaries/Makefile b/tests/run-make/doctests-keep-binaries/Makefile
index 2c647851ad0b7..e346ab7b79020 100644
--- a/tests/run-make/doctests-keep-binaries/Makefile
+++ b/tests/run-make/doctests-keep-binaries/Makefile
@@ -11,16 +11,16 @@ run:
 	mkdir -p $(TMPDIR)/doctests
 	$(RUSTC) --crate-type rlib t.rs
 	$(RUSTDOC) -Zunstable-options --test --persist-doctests $(TMPDIR)/doctests --extern t=$(TMPDIR)/libt.rlib t.rs
-	$(TMPDIR)/doctests/t_rs_2_0/rust_out
-	$(TMPDIR)/doctests/t_rs_8_0/rust_out
+	$(TMPDIR)/doctests/t_rs_12_0/rust_out
+	$(TMPDIR)/doctests/rust_out_2015_0
 	rm -rf $(TMPDIR)/doctests
 
 no_run:
 	mkdir -p $(TMPDIR)/doctests
 	$(RUSTC) --crate-type rlib t.rs
 	$(RUSTDOC) -Zunstable-options --test --persist-doctests $(TMPDIR)/doctests --extern t=$(TMPDIR)/libt.rlib t.rs --no-run
-	$(TMPDIR)/doctests/t_rs_2_0/rust_out
-	$(TMPDIR)/doctests/t_rs_8_0/rust_out
+	$(TMPDIR)/doctests/t_rs_12_0/rust_out
+	$(TMPDIR)/doctests/rust_out_2015_0
 	rm -rf $(TMPDIR)/doctests
 
 # Behavior with --test-run-directory with relative paths.
diff --git a/tests/run-make/doctests-keep-binaries/t.rs b/tests/run-make/doctests-keep-binaries/t.rs
index c38cf0a0b25d4..806f54764779d 100644
--- a/tests/run-make/doctests-keep-binaries/t.rs
+++ b/tests/run-make/doctests-keep-binaries/t.rs
@@ -8,4 +8,12 @@ pub fn foople() {}
 /// ```
 /// t::florp();
 /// ```
+///
+/// ```
+/// #![no_std]
+///
+/// fn main() {
+///     let x = 12;
+/// }
+/// ```
 pub fn florp() {}