From 48961c8861eb0eb7b4d3f101072ed13b55e3be45 Mon Sep 17 00:00:00 2001
From: Julian Orth <ju.orth@gmail.com>
Date: Thu, 21 May 2020 12:39:12 +0200
Subject: [PATCH] Fix module resolution in inner modules with paths

Path attributes with relative paths were previously not treated as
relative to the containing file but as relative to the current working
directory of rustfmt.

The SubModKind enum had a dedicated variant for inner modules with
paths. However, the ordinary variant for inner modules also handles the
presence of path attributes and treats them correctly. Therefore the fix
is to simply remove the dedicated enum variant.

Fixes #3901
Fixes #4076
---
 .../rustfmt-lib/src/formatting/modules.rs       | 17 +----------------
 .../tests/target/inner-module-path/b.rs         |  1 +
 .../tests/target/inner-module-path/c/d.rs       |  1 +
 .../tests/target/inner-module-path/lib.rs       | 10 ++++++++++
 4 files changed, 13 insertions(+), 16 deletions(-)
 create mode 100644 rustfmt-core/rustfmt-lib/tests/target/inner-module-path/b.rs
 create mode 100644 rustfmt-core/rustfmt-lib/tests/target/inner-module-path/c/d.rs
 create mode 100644 rustfmt-core/rustfmt-lib/tests/target/inner-module-path/lib.rs

diff --git a/rustfmt-core/rustfmt-lib/src/formatting/modules.rs b/rustfmt-core/rustfmt-lib/src/formatting/modules.rs
index cb49b62094c..eee19502906 100644
--- a/rustfmt-core/rustfmt-lib/src/formatting/modules.rs
+++ b/rustfmt-core/rustfmt-lib/src/formatting/modules.rs
@@ -37,8 +37,6 @@ enum SubModKind<'a, 'ast> {
     External(PathBuf, DirectoryOwnership, Cow<'ast, ast::Mod>),
     /// `mod foo;` with multiple sources.
     MultiExternal(Vec<(PathBuf, DirectoryOwnership, Cow<'ast, ast::Mod>)>),
-    /// `#[path = "..."] mod foo {}`
-    InternalWithPath(PathBuf),
     /// `mod foo {}`
     Internal(&'a ast::Item),
 }
@@ -154,12 +152,7 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
             self.find_external_module(item.ident, &item.attrs, sub_mod)
         } else {
             // An internal module (`mod foo { /* ... */ }`);
-            if let Some(path) = find_path_value(&item.attrs) {
-                let path = Path::new(&*path.as_str()).to_path_buf();
-                Ok(Some(SubModKind::InternalWithPath(path)))
-            } else {
-                Ok(Some(SubModKind::Internal(item)))
-            }
+            Ok(Some(SubModKind::Internal(item)))
         }
     }
 
@@ -199,14 +192,6 @@ impl<'ast, 'sess, 'c> ModResolver<'ast, 'sess> {
                 };
                 self.visit_sub_mod_after_directory_update(sub_mod, Some(directory))
             }
-            SubModKind::InternalWithPath(mod_path) => {
-                // All `#[path]` files are treated as though they are a `mod.rs` file.
-                let directory = Directory {
-                    path: mod_path,
-                    ownership: DirectoryOwnership::Owned { relative: None },
-                };
-                self.visit_sub_mod_after_directory_update(sub_mod, Some(directory))
-            }
             SubModKind::Internal(ref item) => {
                 self.push_inline_mod_directory(item.ident, &item.attrs);
                 self.visit_sub_mod_after_directory_update(sub_mod, None)
diff --git a/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/b.rs b/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/b.rs
new file mode 100644
index 00000000000..8b137891791
--- /dev/null
+++ b/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/b.rs
@@ -0,0 +1 @@
+
diff --git a/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/c/d.rs b/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/c/d.rs
new file mode 100644
index 00000000000..8b137891791
--- /dev/null
+++ b/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/c/d.rs
@@ -0,0 +1 @@
+
diff --git a/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/lib.rs b/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/lib.rs
new file mode 100644
index 00000000000..fb75d70cd93
--- /dev/null
+++ b/rustfmt-core/rustfmt-lib/tests/target/inner-module-path/lib.rs
@@ -0,0 +1,10 @@
+// rustfmt-recursive: true
+
+#[path = "."]
+mod a {
+    mod b;
+}
+
+mod c {
+    mod d;
+}