Unremap file

.github/workflows/audit.yml

@@ -21,8 +21,8 @@ jobs:
           - advisories
           - bans licenses sources
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
-    - uses: EmbarkStudios/cargo-deny-action@bb137d7af7e4fb67e5f82a49c4fce4fad40782fe  # v2.0.20
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
+    - uses: EmbarkStudios/cargo-deny-action@3c6349835b2b7b196a839186cb8b78e02f7b5f25  # v2.1.1
       # Prevent sudden announcement of a new advisory from failing ci:
       continue-on-error: ${{ matrix.checks == 'advisories' }}
       with:

.github/workflows/contrib.yml

@@ -18,7 +18,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - name: Install mdbook
       run: |
         mkdir mdbook

.github/workflows/main.yml

@@ -58,7 +58,7 @@ jobs:
   rustfmt:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - run: rustup update stable && rustup default stable
     - run: rustup component add rustfmt
     - run: cargo fmt --all --check
@@ -79,30 +79,30 @@ jobs:
     env:
       CARGO_BUILD_WARNINGS: deny
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
       - run: rustup update stable && rustup default stable
       - run: rustup component add clippy
       - run: cargo clippy --workspace --all-targets --no-deps --keep-going
 
   stale-label:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
       - run: rustup update stable && rustup default stable
       - run: cargo stale-label
 
   lint-docs:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
       - run: rustup update stable && rustup default stable
       - run: cargo lint-docs --check
 
   # Ensure Cargo.lock is up-to-date
   lockfile:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
       - run: rustup update stable && rustup default stable
       - run: cargo update -p cargo --locked
 
@@ -113,14 +113,14 @@ jobs:
       BASE_SHA: ${{ github.event.pull_request.base.sha }}
       HEAD_SHA: ${{ github.event.pull_request.head.sha != '' && github.event.pull_request.head.sha || github.sha  }}
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
         with:
           fetch-depth: 0
       - run: rustup update stable && rustup default stable
       - name: Install cargo-semver-checks
         run: |
           mkdir installed-bins
-          curl -Lf https://github.com/obi1kenobi/cargo-semver-checks/releases/download/v0.49.0/cargo-semver-checks-x86_64-unknown-linux-gnu.tar.gz \
+          curl -Lf https://github.com/obi1kenobi/cargo-semver-checks/releases/download/v0.50.0/cargo-semver-checks-x86_64-unknown-linux-gnu.tar.gz \
             | tar -xz --directory=./installed-bins
           echo `pwd`/installed-bins >> $GITHUB_PATH
       - run: ci/validate-version-bump.sh
@@ -193,7 +193,7 @@ jobs:
           other: i686-pc-windows-gnu
     name: Tests ${{ matrix.name }}
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - name: Dump Environment
       run: ci/dump-environment.sh
     # Some tests require stable. Make sure it is set to the most recent stable
@@ -274,21 +274,21 @@ jobs:
   schema:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - run: rustup update stable && rustup default stable
     - run: cargo test -p cargo-util-schemas -F unstable-schema
 
   resolver:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - run: rustup update stable && rustup default stable
     - run: cargo test -p resolver-tests
 
   test_gitoxide:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
       - run: rustup update --no-self-update stable && rustup default stable
       - run: rustup target add i686-unknown-linux-gnu
       - run: rustup target add wasm32-unknown-unknown
@@ -301,7 +301,7 @@ jobs:
   build_std:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - run: rustup update nightly && rustup default nightly
     - run: rustup component add rust-src
     - run: cargo build
@@ -311,7 +311,7 @@ jobs:
   docs:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - run: rustup update nightly && rustup default nightly
     - run: rustup update stable
     - run: rustup component add rust-docs
@@ -339,7 +339,7 @@ jobs:
   msrv:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - uses: taiki-e/install-action@16b05812d776ae1dfaabc8277e421fb6d2506419  # v2.82.7
       with:
         tool: cargo-hack
@@ -350,15 +350,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout Actions Repository
-      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+      uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - name: Spell Check Repo
       uses: crate-ci/typos@bee27e3a4fd1ea2111cf90ab89cd076c870fce14  # v1.48.0
 
   report-timings:
     name: Timing HTML report
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+    - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
     - run: rustup update nightly && rustup default nightly
     - run: cargo build
     - name: Generate timing report for rustfix

.github/workflows/release.yml

@@ -25,7 +25,7 @@ jobs:
 
     steps:
       - name: Checkout the source code
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
+        uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803  # v6.1.0
 
       - name: Publish Cargo to crates.io
         run: ./publish.py

crates/cargo-util/src/process_builder.rs

@@ -561,7 +561,7 @@ impl ProcessBuilder {
 ///
 /// You should set `__CARGO_TEST_FORCE_ARGFILE` to enable this.
 fn debug_force_argfile(retry_enabled: bool) -> bool {
-    cfg!(debug_assertions) && env::var("__CARGO_TEST_FORCE_ARGFILE").is_ok() && retry_enabled
+    retry_enabled && env::var("__CARGO_TEST_FORCE_ARGFILE").is_ok()
 }
 
 /// Creates new pipes for stderr, stdout, and optionally stdin.

doc/book/src/reference/unstable.md

@@ -1585,6 +1585,44 @@ Paths to all other source files will not be affected.
 
 This will not affect any hard-coded paths in the source code, such as in strings.
 
+##### Unremap files
+
+When the `object` scope is active and debuginfo is enabled,
+Cargo writes an unremap file beside each final artifact.
+The file is aimed at helping debuggers substitute sanitized paths back to local ones,
+e.g., via GDB's `set substitute-path` or LLDB's `target.source-map`.
+
+The unremap file name ends with `.trim-paths.jsonl`.
+For example,
+your `my-app` executable would come with an unremap file named
+`my-app.trim-paths.jsonl` beside it.
+
+The unremap file is in JSONL format:
+
+* The first record carries the format version.
+* The second record is file-level metadata,
+  such as the toolchain version and the workspace root.
+* Each following record maps a sanitized path prefix in the artifact
+  (`from`) back to the local path it replaced (`to`),
+  ordered by the `from` prefix.
+  Note that this follows the debugger substitution direction,
+  which is the inverse of `--remap-path-prefix`.
+
+An example of the unremap file:
+
+```json
+{"v":1}
+{"rust_version":"1.96.0-nightly","workspace_root":"/home/me/app"}
+{"from":"/cargo/build-dir","to":"/home/me/app/target"}
+{"from":"/cargo/registry/6f17d22d3f0a95d1","to":"/home/me/.cargo/registry/src/index.crates.io-6f17d22d3f0a95d1"}
+{"from":"/rustc/abc123","to":"/home/me/.rustup/toolchains/nightly/lib/rustlib/src/rust"}
+```
+
+Since it is meant to be a debugging aid,
+it includes absolute paths of your system,
+so there is no artifact privacy guarantee.
+You might want to exclude `*.trim-paths.jsonl` files when distributing artifacts.
+
 #### Environment variable
 
 *as a new entry of ["Environment variables Cargo sets for build scripts"](./environment-variables.md#environment-variables-cargo-sets-for-crates)*

src/compiler/build_context/mod.rs

@@ -1,5 +1,7 @@
 //! [`BuildContext`] is a (mostly) static information about a build task.
 
+use std::path::Path;
+
 use crate::compiler::BuildConfig;
 use crate::compiler::CompileKind;
 use crate::compiler::Unit;
@@ -162,6 +164,18 @@ impl<'a, 'gctx> BuildContext<'a, 'gctx> {
     pub fn extra_args_for(&self, unit: &Unit) -> Option<&Vec<String>> {
         self.extra_compiler_args.get(unit)
     }
+
+    /// Gets the path to the sysroot.
+    ///
+    /// Helper function that uses GlobalContext.
+    pub fn get_sysroot(&self) -> &'gctx Path {
+        // cfg::bad_cfg_discovery tests that these panics aren't reachable
+        let rustc = self
+            .gctx
+            .load_global_rustc(Some(self.ws))
+            .expect("rustc load ok");
+        self.gctx.get_sysroot(&rustc).expect("sysroot fetch ok")
+    }
 }
 
 #[derive(Copy, Clone, Default, Debug)]

src/compiler/build_context/target_info.rs

@@ -53,8 +53,6 @@ pub struct TargetInfo {
     pub supports_std: Option<bool>,
     /// Supported values for `-Csplit-debuginfo=` flag, queried from rustc
     support_split_debuginfo: Vec<String>,
-    /// Path to the sysroot.
-    pub sysroot: PathBuf,
     /// Path to the "lib" directory in the sysroot which rustc uses for linking
     /// target libraries.
     pub sysroot_target_libdir: PathBuf,
@@ -80,6 +78,8 @@ pub enum FileFlavor {
     DebugInfo,
     /// SBOM (Software Bill of Materials pre-cursor) file (e.g. cargo-sbon.json).
     Sbom,
+    /// Unremap file for `-Ztrim-paths` (e.g. `foo.trim-paths.jsonl`).
+    Unremap,
     /// Cross-crate info JSON files generated by rustdoc.
     DocParts,
 }
@@ -165,6 +165,8 @@ impl TargetInfo {
     /// invocation is cached by [`Rustc::cached_output`].
     ///
     /// Search `Tricky` to learn why querying `rustc` several times is needed.
+    ///
+    /// When a Workspace is provided,
     #[tracing::instrument(skip_all)]
     pub fn new(
         gctx: &GlobalContext,
@@ -174,15 +176,25 @@ impl TargetInfo {
     ) -> CargoResult<TargetInfo> {
         let mut rustflags =
             extra_args(gctx, requested_kinds, &rustc.host, None, kind, Flags::Rust)?;
+
+        let sysroot = gctx.get_sysroot(rustc)?;
+        let sysroot_target_libdir = sysroot
+            .join("lib")
+            .join("rustlib")
+            .join(match &kind {
+                CompileKind::Host => rustc.host.as_str(),
+                CompileKind::Target(target) => target.short_name(),
+            })
+            .join("lib");
+
         let mut turn = 0;
         loop {
             let extra_fingerprint = kind.fingerprint_hash();
 
             // Query rustc for several kinds of info from each line of output:
             // 0) file-names (to determine output file prefix/suffix for given crate type)
-            // 1) sysroot
-            // 2) split-debuginfo
-            // 3) cfg
+            // 1) split-debuginfo
+            // 2) cfg
             //
             // Search `--print` to see what we query so far.
             let mut process = rustc.workspace_process();
@@ -216,7 +228,6 @@ impl TargetInfo {
                 process.arg("--crate-type").arg(crate_type.as_str());
             }
 
-            process.arg("--print=sysroot");
             process.arg("--print=split-debuginfo");
             process.arg("--print=crate-name"); // `___` as a delimiter.
             process.arg("--print=cfg");
@@ -238,22 +249,6 @@ impl TargetInfo {
                 map.insert(crate_type.clone(), out);
             }
 
-            let Some(line) = lines.next() else {
-                return error_missing_print_output("sysroot", &process, &output, &error);
-            };
-            let sysroot = PathBuf::from(line);
-            let sysroot_target_libdir = {
-                let mut libdir = sysroot.clone();
-                libdir.push("lib");
-                libdir.push("rustlib");
-                libdir.push(match &kind {
-                    CompileKind::Host => rustc.host.as_str(),
-                    CompileKind::Target(target) => target.short_name(),
-                });
-                libdir.push("lib");
-                libdir
-            };
-
             let support_split_debuginfo = {
                 // HACK: abuse `--print=crate-name` to use `___` as a delimiter.
                 let mut res = Vec::new();
@@ -352,7 +347,6 @@ impl TargetInfo {
             return Ok(TargetInfo {
                 crate_type_process,
                 crate_types: RefCell::new(map),
-                sysroot,
                 sysroot_target_libdir,
                 rustflags: rustflags.into(),
                 rustdocflags: extra_args(

src/compiler/build_runner/compilation_files.rs

@@ -10,6 +10,7 @@ use std::sync::Arc;
 use tracing::debug;
 
 use super::{BuildContext, BuildRunner, CompileKind, FileFlavor, Layout};
+use crate::compiler::trim_paths;
 use crate::compiler::{CompileMode, CompileTarget, CrateType, FileType, Unit};
 use crate::util::{self, CargoResult, OnceExt, StableHasher};
 use crate::workspace::{Target, TargetKind, Workspace};
@@ -612,6 +613,28 @@ impl<'a, 'gctx: 'a> CompilationFiles<'a, 'gctx> {
                         .collect();
                     outputs.extend(sbom_files.into_iter());
                 }
+
+                // Only generates unremap files for root units.
+                // FIXME: might need to consider artifact dependencies?
+                if bcx.roots.contains(unit) && trim_paths::should_emit_unremap_file(unit) {
+                    let unremap_files: Vec<_> = outputs
+                        .iter()
+                        .filter(|o| matches!(o.flavor, FileFlavor::Normal | FileFlavor::Linkable))
+                        .map(|output| OutputFile {
+                            path: trim_paths::append_unremap_suffix(&output.path),
+                            hardlink: output
+                                .hardlink
+                                .as_ref()
+                                .map(trim_paths::append_unremap_suffix),
+                            export_path: output
+                                .export_path
+                                .as_ref()
+                                .map(trim_paths::append_unremap_suffix),
+                            flavor: FileFlavor::Unremap,
+                        })
+                        .collect();
+                    outputs.extend(unremap_files.into_iter());
+                }
                 outputs
             }
         };
@@ -735,7 +758,7 @@ fn compute_metadata(
         // SourceId for stdlib crates is an absolute path inside the sysroot.
         // Pass the sysroot as workspace root so that we hash a relative path.
         // This avoids the metadata hash changing depending on where the user installed rustc.
-        &bcx.target_data.get_info(unit.kind).unwrap().sysroot
+        &bcx.get_sysroot()
     } else {
         bcx.ws.root()
     };