fix(trim-paths): remap all paths to build.build-dir

Remap all paths pointing to `build.build-dir`,
i.e., `[BUILD_DIR]/debug/deps/foo-[HASH].dwo` would be remapped to
`/cargo/build-dir/debug/deps/foo-[HASH].dwo`
(note the `/cargo/build-dir` prefix).

This covers scenarios like:

* Build script generated code. For example, a build script may call `file!`
  macros, and the associated crate uses [`include!`] to include the expanded
  [`file!`] macro in-place via the `OUT_DIR` environment.
* On Linux, `DW_AT_GNU_dwo_name` that contains paths to split debuginfo
  files (dwp and dwo).

Author: weihanglo

src/cargo/core/compiler/mod.rs

@@ -1393,6 +1393,7 @@ fn trim_paths_args_rustdoc(
     // Order of `--remap-path-prefix` flags is important for `-Zbuild-std`.
     // We want to show `/rustc/<hash>/library/std` instead of `std-0.0.0`.
     cmd.arg(package_remap(build_runner, unit));
+    cmd.arg(build_dir_remap(build_runner));
     cmd.arg(sysroot_remap(build_runner, unit));
 
     Ok(())
@@ -1420,6 +1421,7 @@ fn trim_paths_args(
     // Order of `--remap-path-prefix` flags is important for `-Zbuild-std`.
     // We want to show `/rustc/<hash>/library/std` instead of `std-0.0.0`.
     cmd.arg(package_remap(build_runner, unit));
+    cmd.arg(build_dir_remap(build_runner));
     cmd.arg(sysroot_remap(build_runner, unit));
 
     Ok(())
@@ -1493,6 +1495,26 @@ fn package_remap(build_runner: &BuildRunner<'_, '_>, unit: &Unit) -> OsString {
     remap
 }
 
+/// Remap all paths pointing to `build.build-dir`,
+/// i.e., `[BUILD_DIR]/debug/deps/foo-[HASH].dwo` would be remapped to
+/// `/cargo/build-dir/debug/deps/foo-[HASH].dwo`
+/// (note the `/cargo/build-dir` prefix).
+///
+/// This covers scenarios like:
+///
+/// * Build script generated code. For example, a build script may call `file!`
+///   macros, and the associated crate uses [`include!`] to include the expanded
+///   [`file!`] macro in-place via the `OUT_DIR` environment.
+/// * On Linux, `DW_AT_GNU_dwo_name` that contains paths to split debuginfo
+///   files (dwp and dwo).
+fn build_dir_remap(build_runner: &BuildRunner<'_, '_>) -> OsString {
+    let build_dir = build_runner.bcx.ws.build_dir();
+    let mut remap = OsString::from("--remap-path-prefix=");
+    remap.push(build_dir.as_path_unlocked());
+    remap.push("=/cargo/build-dir");
+    remap
+}
+
 /// Generates the `--check-cfg` arguments for the `unit`.
 fn check_cfg_args(unit: &Unit) -> Vec<OsString> {
     // The routine below generates the --check-cfg arguments. Our goals here are to

tests/testsuite/profile_trim_paths.rs

@@ -297,7 +297,7 @@ fn registry_dependency_with_build_script_codegen() {
         .masquerade_as_nightly_cargo(&["-Ztrim-paths"])
         // Macros should be sanitized
         .with_stdout_data(str![[r#"
-[ROOT]/foo/target/debug/build/bar-[HASH]/out/bindings.rs
+/cargo/build-dir/debug/build/bar-[HASH]/out/bindings.rs
 
 "#]]) // Omit the hash of Source URL
         .with_stderr_data(str![[r#"
@@ -308,7 +308,7 @@ fn registry_dependency_with_build_script_codegen() {
 [COMPILING] bar v0.0.1
 [RUNNING] `rustc --crate-name build_script_build [..]-Zremap-path-scope=object --remap-path-prefix=[ROOT]/home/.cargo/registry/src= --remap-path-prefix=[..]/lib/rustlib/src/rust=/rustc/[..]`
 [RUNNING] `[ROOT]/foo/target/debug/build/bar-[HASH]/build-script-build`
-[RUNNING] `rustc --crate-name bar [..]-Zremap-path-scope=object --remap-path-prefix=[ROOT]/home/.cargo/registry/src= --remap-path-prefix=[..]/lib/rustlib/src/rust=/rustc/[..]`
+[RUNNING] `rustc --crate-name bar [..]-Zremap-path-scope=object --remap-path-prefix=[ROOT]/home/.cargo/registry/src= --remap-path-prefix=[ROOT]/foo/target=/cargo/build-dir --remap-path-prefix=[..]/lib/rustlib/src/rust=/rustc/[..]
 [COMPILING] foo v0.0.1 ([ROOT]/foo)
 [RUNNING] `rustc --crate-name foo [..]-Zremap-path-scope=object --remap-path-prefix=[ROOT]/foo=. --remap-path-prefix=[..]/lib/rustlib/src/rust=/rustc/[..]`
 [FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
@@ -694,15 +694,6 @@ fn object_works_helper(split_debuginfo: &str, run: impl Fn(&std::path::Path) ->
             }
         }
 
-        #[cfg(target_os = "linux")]
-        {
-            // To fix this, we should also remap build.build-dir.
-            // See <https://github.com/rust-lang/cargo/pull/15610/commits/a55c7f88fb8d592d993740176da95fc5d1a362e0#r2119070640>
-            if memchr::memmem::find(line, b"DW_AT_GNU_dwo_name").is_some() {
-                continue;
-            }
-        }
-
         panic!(
             "unexpected untrimmed symbol: {}",
             String::from_utf8(line.into()).unwrap()