Test codegen when setting deployment target

src/tools/run-make-support/src/lib.rs

@@ -73,7 +73,7 @@ pub use env::{env_var, env_var_os, set_current_dir};
 pub use run::{cmd, run, run_fail, run_with_args};
 
 /// Helpers for checking target information.
-pub use targets::{is_darwin, is_msvc, is_windows, llvm_components_contain, target, uname};
+pub use targets::{is_darwin, is_msvc, is_windows, llvm_components_contain, target, uname, apple_os};
 
 /// Helpers for building names of output artifacts that are potentially target-specific.
 pub use artifact_names::{

src/tools/run-make-support/src/targets.rs

@@ -28,6 +28,24 @@ pub fn is_darwin() -> bool {
     target().contains("darwin")
 }
 
+/// Get the target OS on Apple operating systems.
+#[must_use]
+pub fn apple_os() -> &'static str {
+    if target().contains("darwin") {
+        "macos"
+    } else if target().contains("ios") {
+        "ios"
+    } else if target().contains("tvos") {
+        "tvos"
+    } else if target().contains("watchos") {
+        "watchos"
+    } else if target().contains("visionos") {
+        "visionos"
+    } else {
+        panic!("not an Apple OS")
+    }
+}
+
 /// Check if `component` is within `LLVM_COMPONENTS`
 #[must_use]
 pub fn llvm_components_contain(component: &str) -> bool {

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -6,7 +6,6 @@ run-make/incr-add-rust-src-component/Makefile
 run-make/issue-84395-lto-embed-bitcode/Makefile
 run-make/jobserver-error/Makefile
 run-make/libs-through-symlinks/Makefile
-run-make/macos-deployment-target/Makefile
 run-make/split-debuginfo/Makefile
 run-make/symbol-mangling-hashed/Makefile
 run-make/translation/Makefile

tests/run-make/apple-deployment-target/foo.rs

@@ -0,0 +1 @@
+fn main() {}

tests/run-make/apple-deployment-target/rmake.rs

@@ -0,0 +1,157 @@
+//! Test codegen when setting deployment targets on Apple platforms.
+//!
+//! This is important since its a compatibility hazard. The linker will
+//! generate load commands differently based on what minimum OS it can assume.
+//!
+//! See https://github.com/rust-lang/rust/pull/105123.
+
+//@ only-apple
+
+use run_make_support::{apple_os, cmd, run_in_tmpdir, rustc, target};
+
+/// Run vtool to check the `minos` field in LC_BUILD_VERSION.
+///
+/// On lower deployment targets, LC_VERSION_MIN_MACOSX, LC_VERSION_MIN_IPHONEOS and similar
+/// are used instead of LC_BUILD_VERSION - these have a `version` field, so also check that.
+#[track_caller]
+fn minos(file: &str, version: &str) {
+    cmd("vtool")
+        .arg("-show-build")
+        .arg(file)
+        .run()
+        .assert_stdout_contains_regex(format!("(minos|version) {version}"));
+}
+
+fn main() {
+    // These versions should generally be higher than the default versions
+    let (env_var, example_version, higher_example_version) = match apple_os() {
+        "macos" => ("MACOSX_DEPLOYMENT_TARGET", "12.0", "13.0"),
+        // armv7s-apple-ios and i386-apple-ios only supports iOS 10.0
+        "ios" if target() == "armv7s-apple-ios" || target() == "i386-apple-ios" => {
+            ("IPHONEOS_DEPLOYMENT_TARGET", "10.0", "10.0")
+        }
+        "ios" => ("IPHONEOS_DEPLOYMENT_TARGET", "15.0", "16.0"),
+        "watchos" => ("WATCHOS_DEPLOYMENT_TARGET", "7.0", "9.0"),
+        "tvos" => ("TVOS_DEPLOYMENT_TARGET", "14.0", "15.0"),
+        "visionos" => ("XROS_DEPLOYMENT_TARGET", "1.1", "1.2"),
+        _ => unreachable!(),
+    };
+    let default_version =
+        rustc().target(target()).env_remove(env_var).print("deployment-target").run().stdout_utf8();
+    let default_version = default_version.strip_prefix("deployment_target=").unwrap().trim();
+
+    // Test that version makes it to the object file.
+    run_in_tmpdir(|| {
+        let rustc = || {
+            let mut rustc = rustc();
+            rustc.target(target());
+            rustc.crate_type("lib");
+            rustc.emit("obj");
+            rustc.input("foo.rs");
+            rustc.output("foo.o");
+            rustc
+        };
+
+        rustc().env(env_var, example_version).run();
+        minos("foo.o", example_version);
+
+        // FIXME(madsmtm): Doesn't work on Mac Catalyst and the simulator.
+        if !target().contains("macabi") && !target().contains("sim") {
+            rustc().env_remove(env_var).run();
+            minos("foo.o", default_version);
+        }
+    });
+
+    // Test that version makes it to the linker when linking dylibs.
+    run_in_tmpdir(|| {
+        // Certain watchOS targets don't support dynamic linking, so we disable the test on those.
+        if apple_os() == "watchos" {
+            return;
+        }
+
+        let rustc = || {
+            let mut rustc = rustc();
+            rustc.target(target());
+            rustc.crate_type("dylib");
+            rustc.input("foo.rs");
+            rustc.output("libfoo.dylib");
+            rustc
+        };
+
+        rustc().env(env_var, example_version).run();
+        minos("libfoo.dylib", example_version);
+
+        // FIXME(madsmtm): Deployment target is not currently passed properly to linker
+        // rustc().env_remove(env_var).run();
+        // minos("libfoo.dylib", default_version);
+
+        // Test with ld64 instead
+
+        rustc().arg("-Clinker-flavor=ld").env(env_var, example_version).run();
+        minos("libfoo.dylib", example_version);
+
+        rustc().arg("-Clinker-flavor=ld").env_remove(env_var).run();
+        minos("libfoo.dylib", default_version);
+    });
+
+    // Test that version makes it to the linker when linking executables.
+    run_in_tmpdir(|| {
+        let rustc = || {
+            let mut rustc = rustc();
+            rustc.target(target());
+            rustc.crate_type("bin");
+            rustc.input("foo.rs");
+            rustc.output("foo");
+            rustc
+        };
+
+        // FIXME(madsmtm): Doesn't work on watchOS for some reason?
+        if !target().contains("watchos") {
+            rustc().env(env_var, example_version).run();
+            minos("foo", example_version);
+
+            // FIXME(madsmtm): Deployment target is not currently passed properly to linker
+            // rustc().env_remove(env_var).run();
+            // minos("foo", default_version);
+        }
+
+        // Test with ld64 instead
+
+        rustc().arg("-Clinker-flavor=ld").env(env_var, example_version).run();
+        minos("foo", example_version);
+
+        rustc().arg("-Clinker-flavor=ld").env_remove(env_var).run();
+        minos("foo", default_version);
+    });
+
+    // Test that changing the deployment target busts the incremental cache.
+    run_in_tmpdir(|| {
+        let rustc = || {
+            let mut rustc = rustc();
+            rustc.target(target());
+            rustc.incremental("incremental");
+            rustc.crate_type("lib");
+            rustc.emit("obj");
+            rustc.input("foo.rs");
+            rustc.output("foo.o");
+            rustc
+        };
+
+        // FIXME(madsmtm): Incremental cache is not yet busted
+        // https://github.com/rust-lang/rust/issues/118204
+        let higher_example_version = example_version;
+        let default_version = example_version;
+
+        rustc().env(env_var, example_version).run();
+        minos("foo.o", example_version);
+
+        rustc().env(env_var, higher_example_version).run();
+        minos("foo.o", higher_example_version);
+
+        // FIXME(madsmtm): Doesn't work on Mac Catalyst and the simulator.
+        if !target().contains("macabi") && !target().contains("sim") {
+            rustc().env_remove(env_var).run();
+            minos("foo.o", default_version);
+        }
+    });
+}