8 files changed, 147 insertions, 133 deletions

diff --git a/crates/ra_cargo_watch/src/lib.rs b/crates/ra_cargo_watch/src/lib.rs
index bbe634603..9af9c347d 100644
--- a/crates/ra_cargo_watch/src/lib.rs
+++ b/crates/ra_cargo_watch/src/lib.rs
@@ -9,6 +9,7 @@ use lsp_types::{
 };
 use std::{
     collections::HashMap,
+    io::BufReader,
     path::PathBuf,
     process::{Command, Stdio},
     sync::Arc,
@@ -215,8 +216,10 @@ impl CheckWatcherThread {
                 self.last_update_req.take();
                 task_send.send(CheckTask::ClearDiagnostics).unwrap();
 
-                // By replacing the watcher, we drop the previous one which
-                // causes it to shut down automatically.
+                // Replace with a dummy watcher first so we drop the original and wait for completion
+                std::mem::replace(&mut self.watcher, WatchThread::dummy());
+
+                // Then create the actual new watcher
                 self.watcher = WatchThread::new(&self.options, &self.workspace_root);
             }
         }
@@ -347,7 +350,9 @@ impl WatchThread {
             // which will break out of the loop, and continue the shutdown
             let _ = message_send.send(CheckEvent::Begin);
 
-            for message in cargo_metadata::parse_messages(command.stdout.take().unwrap()) {
+            for message in
+                cargo_metadata::parse_messages(BufReader::new(command.stdout.take().unwrap()))
+            {
                 let message = match message {
                     Ok(message) => message,
                     Err(err) => {
@@ -356,6 +361,14 @@ impl WatchThread {
                     }
                 };
 
+                // Skip certain kinds of messages to only spend time on what's useful
+                match &message {
+                    Message::CompilerArtifact(artifact) if artifact.fresh => continue,
+                    Message::BuildScriptExecuted(_) => continue,
+                    Message::Unknown => continue,
+                    _ => {}
+                }
+
                 match message_send.send(CheckEvent::Msg(message)) {
                     Ok(()) => {}
                     Err(_err) => {
diff --git a/crates/ra_hir_def/src/nameres.rs b/crates/ra_hir_def/src/nameres.rs
index 27c12e46c..852304dd0 100644
--- a/crates/ra_hir_def/src/nameres.rs
+++ b/crates/ra_hir_def/src/nameres.rs
@@ -229,6 +229,46 @@ impl CrateDefMap {
             self.resolve_path_fp_with_macro(db, ResolveMode::Other, original_module, path, shadow);
         (res.resolved_def, res.segment_index)
     }
+
+    // FIXME: this can use some more human-readable format (ideally, an IR
+    // even), as this should be a great debugging aid.
+    pub fn dump(&self) -> String {
+        let mut buf = String::new();
+        go(&mut buf, self, "\ncrate", self.root);
+        return buf.trim().to_string();
+
+        fn go(buf: &mut String, map: &CrateDefMap, path: &str, module: LocalModuleId) {
+            *buf += path;
+            *buf += "\n";
+
+            let mut entries: Vec<_> = map.modules[module].scope.resolutions().collect();
+            entries.sort_by_key(|(name, _)| name.clone());
+
+            for (name, def) in entries {
+                *buf += &format!("{}:", name);
+
+                if def.types.is_some() {
+                    *buf += " t";
+                }
+                if def.values.is_some() {
+                    *buf += " v";
+                }
+                if def.macros.is_some() {
+                    *buf += " m";
+                }
+                if def.is_none() {
+                    *buf += " _";
+                }
+
+                *buf += "\n";
+            }
+
+            for (name, child) in map.modules[module].children.iter() {
+                let path = path.to_string() + &format!("::{}", name);
+                go(buf, map, &path, *child);
+            }
+        }
+    }
 }
 
 impl ModuleData {
diff --git a/crates/ra_hir_def/src/nameres/tests.rs b/crates/ra_hir_def/src/nameres/tests.rs
index 78bcdc850..82f0f835c 100644
--- a/crates/ra_hir_def/src/nameres/tests.rs
+++ b/crates/ra_hir_def/src/nameres/tests.rs
@@ -10,11 +10,10 @@ use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, SourceDatabase};
 use test_utils::covers;
 
-use crate::{db::DefDatabase, nameres::*, test_db::TestDB, LocalModuleId};
+use crate::{db::DefDatabase, nameres::*, test_db::TestDB};
 
 fn def_map(fixture: &str) -> String {
-    let dm = compute_crate_def_map(fixture);
-    render_crate_def_map(&dm)
+    compute_crate_def_map(fixture).dump()
 }
 
 fn compute_crate_def_map(fixture: &str) -> Arc<CrateDefMap> {
@@ -23,44 +22,6 @@ fn compute_crate_def_map(fixture: &str) -> Arc<CrateDefMap> {
     db.crate_def_map(krate)
 }
 
-fn render_crate_def_map(map: &CrateDefMap) -> String {
-    let mut buf = String::new();
-    go(&mut buf, map, "\ncrate", map.root);
-    return buf.trim().to_string();
-
-    fn go(buf: &mut String, map: &CrateDefMap, path: &str, module: LocalModuleId) {
-        *buf += path;
-        *buf += "\n";
-
-        let mut entries: Vec<_> = map.modules[module].scope.resolutions().collect();
-        entries.sort_by_key(|(name, _)| name.clone());
-
-        for (name, def) in entries {
-            *buf += &format!("{}:", name);
-
-            if def.types.is_some() {
-                *buf += " t";
-            }
-            if def.values.is_some() {
-                *buf += " v";
-            }
-            if def.macros.is_some() {
-                *buf += " m";
-            }
-            if def.is_none() {
-                *buf += " _";
-            }
-
-            *buf += "\n";
-        }
-
-        for (name, child) in map.modules[module].children.iter() {
-            let path = path.to_string() + &format!("::{}", name);
-            go(buf, map, &path, *child);
-        }
-    }
-}
-
 #[test]
 fn crate_def_map_smoke_test() {
     let map = def_map(
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index 908e4862d..08d501ccd 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -847,7 +847,7 @@ impl HirDisplay for ApplicationTy {
             }
             TypeCtor::Array => {
                 let t = self.parameters.as_single();
-                write!(f, "[{};_]", t.display(f.db))?;
+                write!(f, "[{}; _]", t.display(f.db))?;
             }
             TypeCtor::RawPtr(m) => {
                 let t = self.parameters.as_single();
diff --git a/crates/ra_hir_ty/src/tests/coercion.rs b/crates/ra_hir_ty/src/tests/coercion.rs
index 7e99a42ed..76a1b46c0 100644
--- a/crates/ra_hir_ty/src/tests/coercion.rs
+++ b/crates/ra_hir_ty/src/tests/coercion.rs
@@ -71,42 +71,42 @@ fn test2() {
     [82; 93) '{ loop {} }': T
     [84; 91) 'loop {}': !
     [89; 91) '{}': ()
-    [122; 133) '{ loop {} }': *mut [T;_]
+    [122; 133) '{ loop {} }': *mut [T; _]
     [124; 131) 'loop {}': !
     [129; 131) '{}': ()
     [160; 173) '{     gen() }': *mut [U]
-    [166; 169) 'gen': fn gen<U>() -> *mut [T;_]
-    [166; 171) 'gen()': *mut [U;_]
+    [166; 169) 'gen': fn gen<U>() -> *mut [T; _]
+    [166; 171) 'gen()': *mut [U; _]
     [186; 420) '{     ...rr); }': ()
-    [196; 199) 'arr': &[u8;_]
-    [212; 216) '&[1]': &[u8;_]
-    [213; 216) '[1]': [u8;_]
+    [196; 199) 'arr': &[u8; _]
+    [212; 216) '&[1]': &[u8; _]
+    [213; 216) '[1]': [u8; _]
     [214; 215) '1': u8
     [227; 228) 'a': &[u8]
-    [237; 240) 'arr': &[u8;_]
+    [237; 240) 'arr': &[u8; _]
     [250; 251) 'b': u8
     [254; 255) 'f': fn f<u8>(&[T]) -> T
     [254; 260) 'f(arr)': u8
-    [256; 259) 'arr': &[u8;_]
+    [256; 259) 'arr': &[u8; _]
     [270; 271) 'c': &[u8]
     [280; 287) '{ arr }': &[u8]
-    [282; 285) 'arr': &[u8;_]
+    [282; 285) 'arr': &[u8; _]
     [297; 298) 'd': u8
     [301; 302) 'g': fn g<u8>(S<&[T]>) -> T
     [301; 316) 'g(S { a: arr })': u8
     [303; 315) 'S { a: arr }': S<&[u8]>
-    [310; 313) 'arr': &[u8;_]
-    [326; 327) 'e': [&[u8];_]
-    [341; 346) '[arr]': [&[u8];_]
-    [342; 345) 'arr': &[u8;_]
-    [356; 357) 'f': [&[u8];_]
-    [371; 379) '[arr; 2]': [&[u8];_]
-    [372; 375) 'arr': &[u8;_]
+    [310; 313) 'arr': &[u8; _]
+    [326; 327) 'e': [&[u8]; _]
+    [341; 346) '[arr]': [&[u8]; _]
+    [342; 345) 'arr': &[u8; _]
+    [356; 357) 'f': [&[u8]; _]
+    [371; 379) '[arr; 2]': [&[u8]; _]
+    [372; 375) 'arr': &[u8; _]
     [377; 378) '2': usize
     [389; 390) 'g': (&[u8], &[u8])
     [407; 417) '(arr, arr)': (&[u8], &[u8])
-    [408; 411) 'arr': &[u8;_]
-    [413; 416) 'arr': &[u8;_]
+    [408; 411) 'arr': &[u8; _]
+    [413; 416) 'arr': &[u8; _]
     "###
     );
 }
@@ -122,8 +122,8 @@ fn test() {
         @r###"
     [11; 40) '{     ...[1]; }': ()
     [21; 22) 'x': &[i32]
-    [33; 37) '&[1]': &[i32;_]
-    [34; 37) '[1]': [i32;_]
+    [33; 37) '&[1]': &[i32; _]
+    [34; 37) '[1]': [i32; _]
     [35; 36) '1': i32
     "###);
 }
@@ -159,22 +159,22 @@ fn test(a: A<[u8; 2]>, b: B<[u8; 2]>, c: C<[u8; 2]>) {
     [334; 335) 'x': C<[T]>
     [355; 360) '{ x }': C<[T]>
     [357; 358) 'x': C<[T]>
-    [370; 371) 'a': A<[u8;_]>
-    [385; 386) 'b': B<[u8;_]>
-    [400; 401) 'c': C<[u8;_]>
+    [370; 371) 'a': A<[u8; _]>
+    [385; 386) 'b': B<[u8; _]>
+    [400; 401) 'c': C<[u8; _]>
     [415; 481) '{     ...(c); }': ()
     [425; 426) 'd': A<[{unknown}]>
     [429; 433) 'foo1': fn foo1<{unknown}>(A<[T]>) -> A<[T]>
     [429; 436) 'foo1(a)': A<[{unknown}]>
-    [434; 435) 'a': A<[u8;_]>
+    [434; 435) 'a': A<[u8; _]>
     [446; 447) 'e': B<[u8]>
     [450; 454) 'foo2': fn foo2<u8>(B<[T]>) -> B<[T]>
     [450; 457) 'foo2(b)': B<[u8]>
-    [455; 456) 'b': B<[u8;_]>
+    [455; 456) 'b': B<[u8; _]>
     [467; 468) 'f': C<[u8]>
     [471; 475) 'foo3': fn foo3<u8>(C<[T]>) -> C<[T]>
     [471; 478) 'foo3(c)': C<[u8]>
-    [476; 477) 'c': C<[u8;_]>
+    [476; 477) 'c': C<[u8; _]>
     "###
     );
 }
@@ -204,12 +204,12 @@ fn test() {
     [72; 97) '{     ...     }': &[i32]
     [82; 85) 'foo': fn foo<i32>(&[T]) -> &[T]
     [82; 91) 'foo(&[1])': &[i32]
-    [86; 90) '&[1]': &[i32;_]
-    [87; 90) '[1]': [i32;_]
+    [86; 90) '&[1]': &[i32; _]
+    [87; 90) '[1]': [i32; _]
     [88; 89) '1': i32
-    [103; 123) '{     ...     }': &[i32;_]
-    [113; 117) '&[1]': &[i32;_]
-    [114; 117) '[1]': [i32;_]
+    [103; 123) '{     ...     }': &[i32; _]
+    [113; 117) '&[1]': &[i32; _]
+    [114; 117) '[1]': [i32; _]
     [115; 116) '1': i32
     "###
     );
@@ -237,15 +237,15 @@ fn test() {
     [60; 61) 'x': &[i32]
     [64; 123) 'if tru...     }': &[i32]
     [67; 71) 'true': bool
-    [72; 92) '{     ...     }': &[i32;_]
-    [82; 86) '&[1]': &[i32;_]
-    [83; 86) '[1]': [i32;_]
+    [72; 92) '{     ...     }': &[i32; _]
+    [82; 86) '&[1]': &[i32; _]
+    [83; 86) '[1]': [i32; _]
     [84; 85) '1': i32
     [98; 123) '{     ...     }': &[i32]
     [108; 111) 'foo': fn foo<i32>(&[T]) -> &[T]
     [108; 117) 'foo(&[1])': &[i32]
-    [112; 116) '&[1]': &[i32;_]
-    [113; 116) '[1]': [i32;_]
+    [112; 116) '&[1]': &[i32; _]
+    [113; 116) '[1]': [i32; _]
     [114; 115) '1': i32
     "###
     );
@@ -277,16 +277,16 @@ fn test(i: i32) {
     [88; 89) '2': i32
     [93; 96) 'foo': fn foo<i32>(&[T]) -> &[T]
     [93; 102) 'foo(&[2])': &[i32]
-    [97; 101) '&[2]': &[i32;_]
-    [98; 101) '[2]': [i32;_]
+    [97; 101) '&[2]': &[i32; _]
+    [98; 101) '[2]': [i32; _]
     [99; 100) '2': i32
     [112; 113) '1': i32
-    [117; 121) '&[1]': &[i32;_]
-    [118; 121) '[1]': [i32;_]
+    [117; 121) '&[1]': &[i32; _]
+    [118; 121) '[1]': [i32; _]
     [119; 120) '1': i32
     [131; 132) '_': i32
-    [136; 140) '&[3]': &[i32;_]
-    [137; 140) '[3]': [i32;_]
+    [136; 140) '&[3]': &[i32; _]
+    [137; 140) '[3]': [i32; _]
     [138; 139) '3': i32
     "###
     );
@@ -316,18 +316,18 @@ fn test(i: i32) {
     [70; 147) 'match ...     }': &[i32]
     [76; 77) 'i': i32
     [88; 89) '1': i32
-    [93; 97) '&[1]': &[i32;_]
-    [94; 97) '[1]': [i32;_]
+    [93; 97) '&[1]': &[i32; _]
+    [94; 97) '[1]': [i32; _]
     [95; 96) '1': i32
     [107; 108) '2': i32
     [112; 115) 'foo': fn foo<i32>(&[T]) -> &[T]
     [112; 121) 'foo(&[2])': &[i32]
-    [116; 120) '&[2]': &[i32;_]
-    [117; 120) '[2]': [i32;_]
+    [116; 120) '&[2]': &[i32; _]
+    [117; 120) '[2]': [i32; _]
     [118; 119) '2': i32
     [131; 132) '_': i32
-    [136; 140) '&[3]': &[i32;_]
-    [137; 140) '[3]': [i32;_]
+    [136; 140) '&[3]': &[i32; _]
+    [137; 140) '[3]': [i32; _]
     [138; 139) '3': i32
     "###
     );
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index aa948dcbf..02bab6dbe 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -102,7 +102,7 @@ fn test() {
     [11; 48) '{     ...&y]; }': ()
     [21; 22) 'y': &{unknown}
     [25; 32) 'unknown': &{unknown}
-    [38; 45) '[y, &y]': [&&{unknown};_]
+    [38; 45) '[y, &y]': [&&{unknown}; _]
     [39; 40) 'y': &{unknown}
     [42; 44) '&y': &&{unknown}
     [43; 44) 'y': &{unknown}
@@ -128,7 +128,7 @@ fn test() {
     [25; 32) 'unknown': &&{unknown}
     [42; 43) 'y': &&{unknown}
     [46; 53) 'unknown': &&{unknown}
-    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown});_]
+    [59; 77) '[(x, y..., &x)]': [(&&&{unknown}, &&&{unknown}); _]
     [60; 66) '(x, y)': (&&&{unknown}, &&&{unknown})
     [61; 62) 'x': &&{unknown}
     [64; 65) 'y': &&{unknown}
@@ -180,8 +180,8 @@ fn test_line_buffer() {
 "#),
         @r###"
     [23; 53) '{     ...n']; }': ()
-    [29; 50) '&[0, b...b'\n']': &[u8;_]
-    [30; 50) '[0, b'...b'\n']': [u8;_]
+    [29; 50) '&[0, b...b'\n']': &[u8; _]
+    [30; 50) '[0, b'...b'\n']': [u8; _]
     [31; 32) '0': u8
     [34; 39) 'b'\n'': u8
     [41; 42) '1': u8
diff --git a/crates/ra_hir_ty/src/tests/simple.rs b/crates/ra_hir_ty/src/tests/simple.rs
index b7204ec00..fdab9c187 100644
--- a/crates/ra_hir_ty/src/tests/simple.rs
+++ b/crates/ra_hir_ty/src/tests/simple.rs
@@ -28,7 +28,7 @@ mod boxed {
 
 "#,
     );
-    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32;_]>)", type_at_pos(&db, pos));
+    assert_eq!("(Box<i32>, Box<Box<i32>>, Box<&i32>, Box<[i32; _]>)", type_at_pos(&db, pos));
 }
 
 #[test]
@@ -1061,55 +1061,55 @@ fn test(x: &str, y: isize) {
     [9; 10) 'x': &str
     [18; 19) 'y': isize
     [28; 293) '{     ... []; }': ()
-    [38; 39) 'a': [&str;_]
-    [42; 45) '[x]': [&str;_]
+    [38; 39) 'a': [&str; _]
+    [42; 45) '[x]': [&str; _]
     [43; 44) 'x': &str
-    [55; 56) 'b': [[&str;_];_]
-    [59; 65) '[a, a]': [[&str;_];_]
-    [60; 61) 'a': [&str;_]
-    [63; 64) 'a': [&str;_]
-    [75; 76) 'c': [[[&str;_];_];_]
-    [79; 85) '[b, b]': [[[&str;_];_];_]
-    [80; 81) 'b': [[&str;_];_]
-    [83; 84) 'b': [[&str;_];_]
-    [96; 97) 'd': [isize;_]
-    [100; 112) '[y, 1, 2, 3]': [isize;_]
+    [55; 56) 'b': [[&str; _]; _]
+    [59; 65) '[a, a]': [[&str; _]; _]
+    [60; 61) 'a': [&str; _]
+    [63; 64) 'a': [&str; _]
+    [75; 76) 'c': [[[&str; _]; _]; _]
+    [79; 85) '[b, b]': [[[&str; _]; _]; _]
+    [80; 81) 'b': [[&str; _]; _]
+    [83; 84) 'b': [[&str; _]; _]
+    [96; 97) 'd': [isize; _]
+    [100; 112) '[y, 1, 2, 3]': [isize; _]
     [101; 102) 'y': isize
     [104; 105) '1': isize
     [107; 108) '2': isize
     [110; 111) '3': isize
-    [122; 123) 'd': [isize;_]
-    [126; 138) '[1, y, 2, 3]': [isize;_]
+    [122; 123) 'd': [isize; _]
+    [126; 138) '[1, y, 2, 3]': [isize; _]
     [127; 128) '1': isize
     [130; 131) 'y': isize
     [133; 134) '2': isize
     [136; 137) '3': isize
-    [148; 149) 'e': [isize;_]
-    [152; 155) '[y]': [isize;_]
+    [148; 149) 'e': [isize; _]
+    [152; 155) '[y]': [isize; _]
     [153; 154) 'y': isize
-    [165; 166) 'f': [[isize;_];_]
-    [169; 175) '[d, d]': [[isize;_];_]
-    [170; 171) 'd': [isize;_]
-    [173; 174) 'd': [isize;_]
-    [185; 186) 'g': [[isize;_];_]
-    [189; 195) '[e, e]': [[isize;_];_]
-    [190; 191) 'e': [isize;_]
-    [193; 194) 'e': [isize;_]
-    [206; 207) 'h': [i32;_]
-    [210; 216) '[1, 2]': [i32;_]
+    [165; 166) 'f': [[isize; _]; _]
+    [169; 175) '[d, d]': [[isize; _]; _]
+    [170; 171) 'd': [isize; _]
+    [173; 174) 'd': [isize; _]
+    [185; 186) 'g': [[isize; _]; _]
+    [189; 195) '[e, e]': [[isize; _]; _]
+    [190; 191) 'e': [isize; _]
+    [193; 194) 'e': [isize; _]
+    [206; 207) 'h': [i32; _]
+    [210; 216) '[1, 2]': [i32; _]
     [211; 212) '1': i32
     [214; 215) '2': i32
-    [226; 227) 'i': [&str;_]
-    [230; 240) '["a", "b"]': [&str;_]
+    [226; 227) 'i': [&str; _]
+    [230; 240) '["a", "b"]': [&str; _]
     [231; 234) '"a"': &str
     [236; 239) '"b"': &str
-    [251; 252) 'b': [[&str;_];_]
-    [255; 265) '[a, ["b"]]': [[&str;_];_]
-    [256; 257) 'a': [&str;_]
-    [259; 264) '["b"]': [&str;_]
+    [251; 252) 'b': [[&str; _]; _]
+    [255; 265) '[a, ["b"]]': [[&str; _]; _]
+    [256; 257) 'a': [&str; _]
+    [259; 264) '["b"]': [&str; _]
     [260; 263) '"b"': &str
-    [275; 276) 'x': [u8;_]
-    [288; 290) '[]': [u8;_]
+    [275; 276) 'x': [u8; _]
+    [288; 290) '[]': [u8; _]
     "###
     );
 }
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index bc20a49cc..a6ac18f86 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -479,7 +479,7 @@ fn indexing_arrays() {
         @r###"
     [10; 26) '{ &mut...[2]; }': ()
     [12; 23) '&mut [9][2]': &mut {unknown}
-    [17; 20) '[9]': [i32;_]
+    [17; 20) '[9]': [i32; _]
     [17; 23) '[9][2]': {unknown}
     [18; 19) '9': i32
     [21; 22) '2': i32