From 4ad1c6600115593a7c2f2273f138872728d3211a Mon Sep 17 00:00:00 2001
From: Seiichi Uchida <seuchida@gmail.com>
Date: Mon, 6 Aug 2018 22:28:05 +0900
Subject: [PATCH 1/2] Use custom path value if one exists when searching
 modules

---
 src/modules.rs | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/modules.rs b/src/modules.rs
index d94b2dd13332..3316c5a970bc 100644
--- a/src/modules.rs
+++ b/src/modules.rs
@@ -15,6 +15,7 @@ use std::path::{Path, PathBuf};
 use syntax::ast;
 use syntax::codemap;
 use syntax::parse::{parser, DirectoryOwnership};
+use syntax_pos::symbol::Symbol;
 
 use config::FileName;
 use utils::contains_skip;
@@ -38,6 +39,18 @@ pub fn list_files<'a>(
     Ok(result)
 }
 
+fn path_value(attr: &ast::Attribute) -> Option<Symbol> {
+    if attr.name() == "path" {
+        attr.value_str()
+    } else {
+        None
+    }
+}
+
+fn find_path_value(attrs: &[ast::Attribute]) -> Option<Symbol> {
+    attrs.iter().flat_map(path_value).next()
+}
+
 /// Recursively list all external modules included in a module.
 fn list_submodules<'a>(
     module: &'a ast::Mod,
@@ -53,7 +66,11 @@ fn list_submodules<'a>(
                 let is_internal =
                     codemap.span_to_filename(item.span) == codemap.span_to_filename(sub_mod.inner);
                 let (dir_path, relative) = if is_internal {
-                    (search_dir.join(&item.ident.to_string()), None)
+                    if let Some(path) = find_path_value(&item.attrs) {
+                        (search_dir.join(&path.as_str()), None)
+                    } else {
+                        (search_dir.join(&item.ident.to_string()), None)
+                    }
                 } else {
                     let (mod_path, relative) =
                         module_file(item.ident, &item.attrs, search_dir, relative, codemap)?;

From a201d856d10913b887f259c5302d4f5dfcebf6a9 Mon Sep 17 00:00:00 2001
From: Seiichi Uchida <seuchida@gmail.com>
Date: Mon, 6 Aug 2018 22:34:58 +0900
Subject: [PATCH 2/2] Add comment

---
 src/modules.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/modules.rs b/src/modules.rs
index 3316c5a970bc..7619c0afa57a 100644
--- a/src/modules.rs
+++ b/src/modules.rs
@@ -47,6 +47,9 @@ fn path_value(attr: &ast::Attribute) -> Option<Symbol> {
     }
 }
 
+// N.B. Even when there are multiple `#[path = ...]` attributes, we just need to
+// examine the first one, since rustc ignores the second and the subsequent ones
+// as unused attributes.
 fn find_path_value(attrs: &[ast::Attribute]) -> Option<Symbol> {
     attrs.iter().flat_map(path_value).next()
 }