Cargo: Command line option to print full file paths

[emoon]

Sometimes it would be good to have full paths printed for filenames when building with Cargo. A typical example would be when building a large tree of code from an editor/IDE and when file paths only gets printed as src/filename.rs it makes it hard for the IDE to find it.

Cargo currently prints full names under certain conditions but there is no way to makes sure that always happen. Adding a command like option like --full-filename-paths or something better would allow editors/IDEs to easier navigate to compile errors/warnings etc.

[dwijnand]

This issue is similar to #5895 and I wonder: by "full file path" do you mean an absolute path, or simply a more consistent path, such as consistently a path relative to the root of the workspace?

[emoon]

Absolute path would be best as it would work in all cases regardless of how your structure looks like.

[librelois]

@dwijnand Any news about the implementation of this option?
It would really be very useful to me.

Thank :)

[emoon]

I took a look at this issue today and got it working with full paths. The diff looks like this.

diff --git a/src/cargo/core/compiler/mod.rs b/src/cargo/core/compiler/mod.rs
index 99fa98747..3e77dc871 100644
--- a/src/cargo/core/compiler/mod.rs
+++ b/src/cargo/core/compiler/mod.rs
@@ -633,8 +633,16 @@ fn path_args(bcx: &BuildContext<'_, '_>, unit: &Unit<'_>) -> (PathBuf, PathBuf)
     };
     assert!(src.is_absolute());
     if unit.pkg.package_id().source_id().is_path() {
-        if let Ok(path) = src.strip_prefix(ws_root) {
-            return (path.to_path_buf(), ws_root.to_path_buf());
+        // This setting allows us to print a full path to rustc as this is
+        // useful to print when getting errors of having the full filename printed
+        // as it makes it easier for editors/IDEs to find the file as the editor
+        // may not be have cwd relative to the file.
+        if true {
+            return (src, ws_root.to_path_buf());
+        } else {
+            if let Ok(path) = src.strip_prefix(ws_root) {
+                return (path.to_path_buf(), ws_root.to_path_buf());
+            }
         }
     }
     (src, unit.pkg.root().to_path_buf())

Now in order to have this fully working either:

1. Always use absolute paths here instead of relative ones. There is a reasoning in the comments for this function why relative paths are used.
2. Add a command line option (to replace the if true above) and pass it down to this code.

I'm not sure what the best option here would be.

[benma]

Bump. It would be great to get this feature, I also rely on absolute paths to jump to the error in my environment.

[catenacyber]

Until this gets in cargo, my workaround is something like

abspath=`cargo metadata | jq -r '.workspace_root'`
export RUSTFLAGS="$RUSTFLAGS --remap-path-prefix src=$abspath/src"