WIP

tests/testsuite/profile_trim_paths.rs

@@ -446,3 +446,101 @@ warning: unused variable: `unused`
         )
         .run();
 }
+
+#[cfg(unix)]
+#[cargo_test(requires_strings, nightly, reason = "-Zremap-path-scope is unstable")]
+fn object_works() {
+    let run_strings = |path| {
+        std::process::Command::new("strings")
+            .arg(path)
+            .output()
+            .expect("strings works")
+    };
+
+    let registry_src = paths::home().join(".cargo/registry/src");
+    let pkg_remap = format!("{}/[..]/bar-0.0.1=bar-0.0.1", registry_src.display());
+    let rust_src = "/lib/rustc/src/rust".as_bytes();
+    let registry_src_bytes = registry_src.as_os_str().as_encoded_bytes();
+
+    Package::new("bar", "0.0.1")
+        .file("Cargo.toml", &basic_manifest("bar", "0.0.1"))
+        .file("src/lib.rs", r#"pub fn f() { println!("{}", file!()); }"#)
+        .publish();
+    let p = project()
+        .file(
+            "Cargo.toml",
+            r#"
+                [package]
+                name = "foo"
+                version = "0.0.1"
+
+                [dependencies]
+                bar = "0.0.1"
+
+                [profile.dev]
+                split-debuginfo = "off" # we verify the executable as a whole
+           "#,
+        )
+        .file("src/main.rs", "fn main() { bar::f(); }")
+        .build();
+
+    let pkg_root = p.root();
+    let pkg_root = pkg_root.as_os_str().as_encoded_bytes();
+
+    p.cargo("build").run();
+
+    let bin_path = p.bin("foo");
+    assert!(bin_path.is_file());
+    let stdout = run_strings(bin_path).stdout;
+    // TODO: re-enable this check when rustc bootstrap disables remapping
+    // <https://github.com/rust-lang/cargo/pull/12625#discussion_r1371714791>
+    // assert!(memchr::memmem::find(&stdout, rust_src).is_some());
+    assert!(memchr::memmem::find(&stdout, registry_src_bytes).is_some());
+    assert!(memchr::memmem::find(&stdout, pkg_root).is_some());
+
+    p.cargo("clean").run();
+
+    p.change_file(
+        "Cargo.toml",
+        r#"
+            [package]
+            name = "foo"
+            version = "0.0.1"
+
+            [dependencies]
+            bar = "0.0.1"
+
+            [profile.dev]
+            trim-paths = "object"
+            split-debuginfo = "off" # we verify the executable as a whole
+       "#,
+    );
+
+    p.cargo("build --verbose -Ztrim-paths")
+        .masquerade_as_nightly_cargo(&["-Ztrim-paths"])
+        .with_stderr(&format!(
+            "\
+[COMPILING] bar v0.0.1
+[RUNNING] `rustc [..]\
+    -Zremap-path-scope=object \
+    --remap-path-prefix=[..]/lib/rustlib/src/rust=/rustc/[..] \
+    --remap-path-prefix={pkg_remap} [..]
+[COMPILING] foo v0.0.1 ([CWD])
+[RUNNING] `rustc [..]\
+    -Zremap-path-scope=object \
+    --remap-path-prefix=[..]/lib/rustlib/src/rust=/rustc/[..] \
+    --remap-path-prefix=[CWD]= [..]
+[FINISHED] dev [..]",
+        ))
+        .run();
+
+    let bin_path = p.bin("foo");
+    assert!(bin_path.is_file());
+    let stdout = run_strings(bin_path).stdout;
+    dbg!(p.root());
+    assert!(memchr::memmem::find(&stdout, rust_src).is_none());
+    assert!(memchr::memmem::find(&stdout, registry_src_bytes).is_none());
+    // TODO: on macOS codegen unit partitions `.rcgu.o` are still there.
+    #[cfg(not(target_os = "macos"))]
+    assert!(memchr::memmem::find(&stdout, pkg_root).is_none());
+}