cargo clean: Validate that target_dir is not a file

src/cargo/ops/cargo_clean.rs

@@ -7,6 +7,7 @@ use crate::util::edit_distance;
 use crate::util::errors::CargoResult;
 use crate::util::interning::InternedString;
 use crate::util::{GlobalContext, Progress, ProgressStyle};
+use annotate_snippets::Level;
 use anyhow::bail;
 use cargo_util::paths;
 use indexmap::{IndexMap, IndexSet};
@@ -49,6 +50,22 @@ pub fn clean(ws: &Workspace<'_>, opts: &CleanOptions<'_>) -> CargoResult<()> {
     let mut clean_ctx = CleanContext::new(gctx);
     clean_ctx.dry_run = opts.dry_run;
 
+    const CLEAN_ABORT_NOTE: &str =
+        "cleaning has been aborted to prevent accidental deletion of unrelated files";
+
+    // make sure target_dir is a directory if it exists so that we don't delete files
+    if let Ok(meta) = fs::symlink_metadata(target_dir.as_path_unlocked()) {
+        // do not error if target_dir is symlink; let cargo delete it
+        if !meta.is_symlink() && !meta.is_dir() {
+            let title = format!("cannot clean `{}`: not a directory", target_dir.display());
+            let report = [Level::ERROR
+                .primary_title(title)
+                .element(Level::NOTE.message(CLEAN_ABORT_NOTE))];
+            gctx.shell().print_report(&report, false)?;
+            return Err(crate::AlreadyPrintedError::new(anyhow::anyhow!("")).into());
+        }
+    }
+
     if opts.doc {
         if !opts.spec.is_empty() {
             // FIXME: https://github.com/rust-lang/cargo/issues/8790

tests/testsuite/clean.rs

@@ -1058,3 +1058,153 @@ fn quiet_does_not_show_summary() {
 "#]])
         .run();
 }
+
+#[cargo_test]
+fn target_dir_is_file() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
+        .file("target", "")
+        .build();
+
+    p.cargo("clean")
+        .with_stderr_data(str![[r#"
+[ERROR] cannot clean `[ROOT]/foo/target`: not a directory
+  |
+  = [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files
+
+"#]])
+        .with_status(101)
+        .run();
+
+    assert!(p.root().join("target").exists());
+}
+
+#[cargo_test]
+fn explicit_target_dir_is_file() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
+        .file("bar", "")
+        .build();
+
+    p.cargo("clean --target-dir bar")
+        .with_stderr_data(str![[r#"
+[ERROR] cannot clean `[ROOT]/foo/bar`: not a directory
+  |
+  = [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files
+
+"#]])
+        .with_status(101)
+        .run();
+
+    assert!(p.root().join("bar").exists());
+}
+
+#[cargo_test]
+fn env_target_dir_is_file() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
+        .file("bar", "")
+        .build();
+
+    p.cargo("clean")
+        .env("CARGO_TARGET_DIR", "bar")
+        .with_stderr_data(str![[r#"
+[ERROR] cannot clean `[ROOT]/foo/bar`: not a directory
+  |
+  = [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files
+
+"#]])
+        .with_status(101)
+        .run();
+
+    assert!(p.root().join("bar").exists());
+}
+
+#[cargo_test]
+fn config_target_dir_is_file() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
+        .file("bar", "")
+        .file(
+            ".cargo/config.toml",
+            "[build]
+        target-dir = 'bar'",
+        )
+        .build();
+
+    p.cargo("clean")
+        .with_stderr_data(str![[r#"
+[ERROR] cannot clean `[ROOT]/foo/bar`: not a directory
+  |
+  = [NOTE] cleaning has been aborted to prevent accidental deletion of unrelated files
+
+"#]])
+        .with_status(101)
+        .run();
+
+    assert!(p.root().join("bar").exists());
+}
+
+#[cargo_test]
+fn target_dir_is_symlink_dir() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
+        .symlink_dir("bar-dest", "target")
+        .file("bar-dest/.keep", "")
+        .build();
+
+    let mut check = p.cargo("clean");
+    #[cfg(windows)]
+    {
+        check.with_stderr_data(str![[r#"
+[REMOVED] 1 file
+
+"#]]);
+    }
+    #[cfg(not(windows))]
+    {
+        check.with_stderr_data(str![[r#"
+[REMOVED] 1 file, [FILE_SIZE]B total
+
+"#]]);
+    }
+    check.with_status(0).run();
+
+    // make sure cargo has not deleted the files of the symlinked target dir
+    assert!(p.root().join("bar-dest/.keep").exists());
+}
+
+#[cargo_test]
+fn target_dir_is_symlink_file() {
+    let p = project()
+        .file("Cargo.toml", &basic_bin_manifest("foo"))
+        .file("src/foo.rs", &main_file(r#""i am foo""#, &[]))
+        .symlink("bar-dest", "target")
+        .file("bar-dest", "")
+        .build();
+
+    let mut check = p.cargo("clean");
+    #[cfg(windows)]
+    {
+        check.with_stderr_data(str![[r#"
+[REMOVED] 1 file
+
+"#]]);
+    }
+    #[cfg(not(windows))]
+    {
+        check.with_stderr_data(str![[r#"
+[REMOVED] 1 file, [FILE_SIZE]B total
+
+"#]]);
+    }
+    check.with_status(0).run();
+
+    // make sure cargo has not deleted the file of the symlinked target dir
+    assert!(p.root().join("bar-dest").exists());
+}