Back out "Set included_dirs based on buck srcs"

Summary:
This breaks handling of generated thrift sources. We need to think about how to handle all these cases in a more principled way. In the mean time, revert, since thrift is more common than the `core` use case this fixed.

Original commit changeset: 25b598122c83

Original Phabricator Diff: D58479338

Reviewed By: davidbarsky, dtolnay

Differential Revision: D58875911

fbshipit-source-id: 4b6d37cbfd0eeb03a1c42bd856475e91ee4fe87e

Author: darichey

integrations/rust-project/src/buck.rs

@@ -150,7 +150,9 @@ pub(crate) fn to_json_project(
             }
         }
 
-        include_dirs.extend(info.src_dirs());
+        if let Some(parent) = root_module.parent() {
+            include_dirs.insert(parent.to_owned());
+        }
 
         let build = if info.in_workspace {
             let build = Build {

integrations/rust-project/src/target.rs

@@ -249,25 +249,6 @@ impl TargetInfo {
 
         cfg
     }
-
-    pub(crate) fn src_dirs(&self) -> Vec<PathBuf> {
-        let mut all_src_dirs: Vec<&Path> = self.srcs.iter().filter_map(|p| p.parent()).collect();
-        all_src_dirs.sort();
-
-        let mut uniq_dirs: Vec<PathBuf> = vec![];
-        for src_dir in all_src_dirs {
-            match uniq_dirs.last() {
-                Some(last_dir) => {
-                    if !src_dir.starts_with(last_dir) {
-                        uniq_dirs.push(src_dir.to_owned());
-                    }
-                }
-                None => uniq_dirs.push(src_dir.to_owned()),
-            }
-        }
-
-        uniq_dirs
-    }
 }
 
 #[derive(Debug, Clone, Deserialize, PartialEq, Eq, Default)]
@@ -365,37 +346,3 @@ fn test_cfg() {
 
     assert_eq!(info.cfg(), expected);
 }
-
-#[test]
-fn test_src_dirs() {
-    let info = TargetInfo {
-        name: "bar".to_owned(),
-        label: "bar".to_owned(),
-        kind: Kind::Library,
-        edition: None,
-        srcs: vec![
-            PathBuf::from("src/foo.rs"),
-            PathBuf::from("src/bar/foo.rs"),
-            PathBuf::from("other/blah.rs"),
-        ],
-        mapped_srcs: FxHashMap::default(),
-        crate_name: None,
-        crate_dynamic: None,
-        crate_root: None,
-        deps: vec![],
-        test_deps: vec![],
-        named_deps: FxHashMap::default(),
-        proc_macro: None,
-        features: vec![],
-        env: FxHashMap::default(),
-        source_folder: PathBuf::from("/tmp"),
-        project_relative_buildfile: PathBuf::from("bar/BUCK"),
-        in_workspace: false,
-        out_dir: None,
-        rustc_flags: vec![],
-    };
-
-    let expected: Vec<PathBuf> = vec![PathBuf::from("other"), PathBuf::from("src")];
-
-    assert_eq!(info.src_dirs(), expected);
-}