Merge #1784

1784: Support textual scoped macros r=matklad a=uHOOCCOOHu

Refactor the old simulation with `global_macro_scope`.

Now it is quite accurate to resolve textual scoped macros.
- Expand textual scoped macros in item and non-item place.
- Support `#[macro_use]` on `mod`.
- Textual scoped macros are collected into `nameres::ModuleScope`, so I think it makes #1727 easier to fix.
- It is implemented in a simple way to `clone()` current scoped macro ids into sub-modules. Though only indices are cloned, it will still increase some resolving time. Well, I've not bench-marked yet.

In my test with vscode extension, it can now successfully expand `dbg!` from `std` without `std::` prefix. "Goto definition" also works. Screenshot here:
<img width="281" alt="Screenshot_20190907_043442" src="https://user-images.githubusercontent.com/14816024/64458794-ddb47900-d128-11e9-95e3-1c8569978825.png">


Co-authored-by: uHOOCCOOHu <[email protected]>

1 files changed, 105 insertions, 3 deletions

diff --git a/crates/ra_hir/src/nameres/tests/macros.rs b/crates/ra_hir/src/nameres/tests/macros.rs
index c62152d26..ebc4d6890 100644
--- a/crates/ra_hir/src/nameres/tests/macros.rs
+++ b/crates/ra_hir/src/nameres/tests/macros.rs
@@ -268,12 +268,114 @@ fn prelude_cycle() {
     );
     assert_snapshot!(map, @r###"
         ⋮crate
-        ⋮foo: t
         ⋮prelude: t
         ⋮
         ⋮crate::prelude
         ⋮declare_mod: m
-        ⋮
-        ⋮crate::foo
+    "###);
+}
+
+#[test]
+fn plain_macros_are_legacy_textual_scoped() {
+    let map = def_map(
+        r#"
+        //- /main.rs
+        mod m1;
+        bar!(NotFoundNotMacroUse);
+
+        mod m2 {
+            foo!(NotFoundBeforeInside2);
+        }
+
+        macro_rules! foo {
+            ($x:ident) => { struct $x; }
+        }
+        foo!(Ok);
+
+        mod m3;
+        foo!(OkShadowStop);
+        bar!(NotFoundMacroUseStop);
+
+        #[macro_use]
+        mod m5 {
+            #[macro_use]
+            mod m6 {
+                macro_rules! foo {
+                    ($x:ident) => { fn $x() {} }
+                }
+            }
+        }
+        foo!(ok_double_macro_use_shadow);
+
+        baz!(NotFoundBefore);
+        #[macro_use]
+        mod m7 {
+            macro_rules! baz {
+                ($x:ident) => { struct $x; }
+            }
+        }
+        baz!(OkAfter);
+
+        //- /m1.rs
+        foo!(NotFoundBeforeInside1);
+        macro_rules! bar {
+            ($x:ident) => { struct $x; }
+        }
+
+        //- /m3/mod.rs
+        foo!(OkAfterInside);
+        macro_rules! foo {
+            ($x:ident) => { fn $x() {} }
+        }
+        foo!(ok_shadow);
+
+        #[macro_use]
+        mod m4;
+        bar!(OkMacroUse);
+
+        //- /m3/m4.rs
+        foo!(ok_shadow_deep);
+        macro_rules! bar {
+            ($x:ident) => { struct $x; }
+        }
+        "#,
+    );
+    assert_snapshot!(map, @r###"
+   ⋮crate
+   ⋮Ok: t v
+   ⋮OkAfter: t v
+   ⋮OkShadowStop: t v
+   ⋮foo: m
+   ⋮m1: t
+   ⋮m2: t
+   ⋮m3: t
+   ⋮m5: t
+   ⋮m7: t
+   ⋮ok_double_macro_use_shadow: v
+   ⋮
+   ⋮crate::m7
+   ⋮baz: m
+   ⋮
+   ⋮crate::m1
+   ⋮bar: m
+   ⋮
+   ⋮crate::m5
+   ⋮m6: t
+   ⋮
+   ⋮crate::m5::m6
+   ⋮foo: m
+   ⋮
+   ⋮crate::m2
+   ⋮
+   ⋮crate::m3
+   ⋮OkAfterInside: t v
+   ⋮OkMacroUse: t v
+   ⋮foo: m
+   ⋮m4: t
+   ⋮ok_shadow: v
+   ⋮
+   ⋮crate::m3::m4
+   ⋮bar: m
+   ⋮ok_shadow_deep: v
     "###);
 }