Stabilize doctest-xcompile

This stabilizes the doctest-xcompile feature by unconditionally enabling
it.

Author: ehuss

src/cargo/core/features.rs

@@ -769,7 +769,6 @@ unstable_cli_options!(
     codegen_backend: bool = ("Enable the `codegen-backend` option in profiles in .cargo/config.toml file"),
     config_include: bool = ("Enable the `include` key in config files"),
     direct_minimal_versions: bool = ("Resolve minimal dependency versions instead of maximum (direct dependencies only)"),
-    doctest_xcompile: bool = ("Compile and run doctests for non-host target using runner config"),
     dual_proc_macros: bool = ("Build proc-macros for both the host and the target"),
     feature_unification: bool = ("Enable new feature unification modes in workspaces"),
     features: Option<Vec<String>>,
@@ -878,6 +877,8 @@ const STABILIZED_LINTS: &str = "The `[lints]` table is now always available.";
 const STABILIZED_CHECK_CFG: &str =
     "Compile-time checking of conditional (a.k.a. `-Zcheck-cfg`) is now always enabled.";
 
+const STABILIZED_DOCTEST_XCOMPILE: &str = "Doctest cross-compiling is now always enabled.";
+
 fn deserialize_comma_separated_list<'de, D>(
     deserializer: D,
 ) -> Result<Option<Vec<String>>, D::Error>
@@ -1274,7 +1275,7 @@ impl CliUnstable {
             "codegen-backend" => self.codegen_backend = parse_empty(k, v)?,
             "config-include" => self.config_include = parse_empty(k, v)?,
             "direct-minimal-versions" => self.direct_minimal_versions = parse_empty(k, v)?,
-            "doctest-xcompile" => self.doctest_xcompile = parse_empty(k, v)?,
+            "doctest-xcompile" => stabilized_warn(k, "1.88", STABILIZED_DOCTEST_XCOMPILE),
             "dual-proc-macros" => self.dual_proc_macros = parse_empty(k, v)?,
             "feature-unification" => self.feature_unification = parse_empty(k, v)?,
             "gc" => self.gc = parse_empty(k, v)?,

src/cargo/ops/cargo_test.rs

@@ -176,7 +176,6 @@ fn run_doc_tests(
 ) -> Result<Vec<UnitTestError>, CliError> {
     let gctx = ws.gctx();
     let mut errors = Vec::new();
-    let doctest_xcompile = gctx.cli_unstable().doctest_xcompile;
     let color = gctx.shell().color_choice();
 
     for doctest_info in &compilation.to_doc_test {
@@ -189,28 +188,6 @@ fn run_doc_tests(
             env,
         } = doctest_info;
 
-        if !doctest_xcompile {
-            match unit.kind {
-                CompileKind::Host => {}
-                CompileKind::Target(target) => {
-                    if target.short_name() != compilation.host {
-                        // Skip doctests, -Zdoctest-xcompile not enabled.
-                        gctx.shell().verbose(|shell| {
-                            shell.note(format!(
-                                "skipping doctests for {} ({}), \
-                                 cross-compilation doctests are not yet supported\n\
-                                 See https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#doctest-xcompile \
-                                 for more information.",
-                                unit.pkg,
-                                unit.target.description_named()
-                            ))
-                        })?;
-                        continue;
-                    }
-                }
-            }
-        }
-
         gctx.shell().status("Doc-tests", unit.target.name())?;
         let mut p = compilation.rustdoc_process(unit, *script_meta)?;
 
@@ -237,19 +214,17 @@ fn run_doc_tests(
             p.arg("--target").arg(target.rustc_target());
         }
 
-        if doctest_xcompile {
-            if let Some((runtool, runtool_args)) = compilation.target_runner(unit.kind) {
-                p.arg("--test-runtool").arg(runtool);
-                for arg in runtool_args {
-                    p.arg("--test-runtool-arg").arg(arg);
-                }
-            }
-            if let Some(linker) = linker {
-                let mut joined = OsString::from("linker=");
-                joined.push(linker);
-                p.arg("-C").arg(joined);
+        if let Some((runtool, runtool_args)) = compilation.target_runner(unit.kind) {
+            p.arg("--test-runtool").arg(runtool);
+            for arg in runtool_args {
+                p.arg("--test-runtool-arg").arg(arg);
             }
         }
+        if let Some(linker) = linker {
+            let mut joined = OsString::from("linker=");
+            joined.push(linker);
+            p.arg("-C").arg(joined);
+        }
 
         if unit.profile.panic != PanicStrategy::Unwind {
             p.arg("-C").arg(format!("panic={}", unit.profile.panic));

src/doc/src/reference/unstable.md

@@ -84,7 +84,6 @@ Each new feature described below should explain how to use it.
     * [root-dir](#root-dir) --- Controls the root directory relative to which paths are printed
 * Compile behavior
     * [mtime-on-use](#mtime-on-use) --- Updates the last-modified timestamp on every dependency every time it is used, to provide a mechanism to delete unused artifacts.
-    * [doctest-xcompile](#doctest-xcompile) --- Supports running doctests with the `--target` flag.
     * [build-std](#build-std) --- Builds the standard library instead of using pre-built binaries.
     * [build-std-features](#build-std-features) --- Sets features to use with the standard library.
     * [binary-dep-depinfo](#binary-dep-depinfo) --- Causes the dep-info file to track binary dependencies.
@@ -277,21 +276,6 @@ Avaiable template variables:
 The `-Zroot-dir` flag sets the root directory relative to which paths are printed.
 This affects both diagnostics and paths emitted by the `file!()` macro.
 
-## doctest-xcompile
-* Tracking Issue: [#7040](https://github.com/rust-lang/cargo/issues/7040)
-* Tracking Rustc Issue: [#64245](https://github.com/rust-lang/rust/issues/64245)
-
-This flag changes `cargo test`'s behavior when handling doctests when
-a target is passed. Currently, if a target is passed that is different
-from the host cargo will simply skip testing doctests. If this flag is
-present, cargo will continue as normal, passing the tests to doctest,
-while also passing it a `--target` option, as well as passing along
-information from `.cargo/config.toml`. See the rustc issue for more information.
-
-```sh
-cargo test --target foo -Zdoctest-xcompile
-```
-
 ## Build-plan
 * Tracking Issue: [#5579](https://github.com/rust-lang/cargo/issues/5579)
 
@@ -2153,3 +2137,7 @@ See [`cargo fix --edition`](../commands/cargo-fix.md) and [The Edition Guide](..
 
 Support for automatically deleting old files was stabilized in Rust 1.88.
 More information can be found in the [config chapter](config.md#cache).
+
+## doctest-xcompile
+
+Doctest cross-compiling is now unconditionally enabled starting in Rust 1.88. Running doctests with `cargo test` will now honor the `--target` flag.

tests/testsuite/artifact_dep.rs

@@ -1246,7 +1246,7 @@ fn non_build_script_deps_adopt_specified_target_unconditionally() {
 }
 
 #[cargo_test]
-fn no_cross_doctests_works_with_artifacts() {
+fn cross_doctests_works_with_artifacts() {
     if cross_compile::disabled() {
         return;
     }
@@ -1302,40 +1302,24 @@ fn no_cross_doctests_works_with_artifacts() {
     println!("c");
     let target = cross_compile::alternate();
 
-    // This will build the library, but does not build or run doc tests.
-    // This should probably be a warning or error.
-    p.cargo("test -Z bindeps -v --doc --target")
-        .arg(&target)
-        .masquerade_as_nightly_cargo(&["bindeps"])
-        .with_stderr_data(str![[r#"
-[COMPILING] bar v0.5.0 ([ROOT]/foo/bar)
-[RUNNING] `rustc --crate-name bar --edition=2015 bar/src/lib.rs [..]--target [ALT_TARGET] [..]
-[RUNNING] `rustc --crate-name bar --edition=2015 bar/src/main.rs [..]--target [ALT_TARGET] [..]
-[COMPILING] foo v0.0.1 ([ROOT]/foo)
-[RUNNING] `rustc --crate-name foo [..]`
-[FINISHED] `test` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
-[NOTE] skipping doctests for foo v0.0.1 ([ROOT]/foo) (lib), cross-compilation doctests are not yet supported
-See https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#doctest-xcompile for more information.
-
-"#]])
-        .run();
-
     if !cross_compile::can_run_on_host() {
         return;
     }
 
-    // This tests the library, but does not run the doc tests.
     p.cargo("test -Z bindeps -v --target")
         .arg(&target)
         .masquerade_as_nightly_cargo(&["bindeps"])
         .with_stderr_data(str![[r#"
-[FRESH] bar v0.5.0 ([ROOT]/foo/bar)
+[COMPILING] bar v0.5.0 ([ROOT]/foo/bar)
+[RUNNING] `rustc --crate-name bar --edition=2015 bar/src/lib.rs [..]--target [ALT_TARGET] [..]
+[RUNNING] `rustc --crate-name bar --edition=2015 bar/src/main.rs [..]--target [ALT_TARGET] [..]
 [COMPILING] foo v0.0.1 ([ROOT]/foo)
-[RUNNING] `rustc --crate-name foo [..]--test[..]
+[RUNNING] `rustc --crate-name foo [..]
+[RUNNING] `rustc --crate-name foo [..]
 [FINISHED] `test` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
 [RUNNING] `[ROOT]/foo/target/[ALT_TARGET]/debug/deps/foo-[HASH][EXE]`
-[NOTE] skipping doctests for foo v0.0.1 ([ROOT]/foo) (lib), cross-compilation doctests are not yet supported
-See https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#doctest-xcompile for more information.
+[DOCTEST] foo
+[RUNNING] `rustdoc [..]--test src/lib.rs --test-run-directory [ROOT]/foo --target [ALT_TARGET] [..]
 
 "#]])
         .run();

tests/testsuite/build_script.rs

@@ -5600,10 +5600,10 @@ test check_target ... ok
 "#]])
         .run();
 
+    // Remove check once 1.88 is stable
     if cargo_test_support::is_nightly() {
-        p.cargo("test --workspace -Z doctest-xcompile --doc --target")
+        p.cargo("test --workspace --doc --target")
             .arg(&target)
-            .masquerade_as_nightly_cargo(&["doctest-xcompile"])
             .with_stdout_data(str![[r#"
 ...
 test foo/src/lib.rs - (line 2) ... ok