25 files changed, 445 insertions, 69 deletions

diff --git a/crates/ra_cli/src/analysis_bench.rs b/crates/ra_cli/src/analysis_bench.rs
index 5e9d0c16d..9e76bcebf 100644
--- a/crates/ra_cli/src/analysis_bench.rs
+++ b/crates/ra_cli/src/analysis_bench.rs
@@ -1,10 +1,14 @@
 use std::{
     path::{Path, PathBuf},
+    sync::Arc,
     time::Instant,
 };
 
-use ra_db::{salsa::Database, SourceDatabase};
-use ra_ide_api::{Analysis, AnalysisHost, FilePosition, LineCol};
+use ra_db::{
+    salsa::{Database, Durability},
+    FileId, SourceDatabase,
+};
+use ra_ide_api::{Analysis, AnalysisChange, AnalysisHost, FilePosition, LineCol};
 
 use crate::Result;
 
@@ -16,7 +20,7 @@ pub(crate) enum Op {
 pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
     let start = Instant::now();
     eprint!("loading: ");
-    let (host, roots) = ra_batch::load_cargo(path)?;
+    let (mut host, roots) = ra_batch::load_cargo(path)?;
     let db = host.raw_database();
     eprintln!("{:?}\n", start.elapsed());
 
@@ -44,7 +48,7 @@ pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
 
     match op {
         Op::Highlight { .. } => {
-            let res = do_work(&host, |analysis| {
+            let res = do_work(&mut host, file_id, |analysis| {
                 analysis.diagnostics(file_id).unwrap();
                 analysis.highlight_as_html(file_id, false).unwrap()
             });
@@ -59,7 +63,7 @@ pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
                 .offset(LineCol { line, col_utf16: column });
             let file_postion = FilePosition { file_id, offset };
 
-            let res = do_work(&host, |analysis| analysis.completions(file_postion));
+            let res = do_work(&mut host, file_id, |analysis| analysis.completions(file_postion));
             if verbose {
                 println!("\n{:#?}", res);
             }
@@ -68,7 +72,7 @@ pub(crate) fn run(verbose: bool, path: &Path, op: Op) -> Result<()> {
     Ok(())
 }
 
-fn do_work<F: Fn(&Analysis) -> T, T>(host: &AnalysisHost, work: F) -> T {
+fn do_work<F: Fn(&Analysis) -> T, T>(host: &mut AnalysisHost, file_id: FileId, work: F) -> T {
     {
         let start = Instant::now();
         eprint!("from scratch:   ");
@@ -84,7 +88,27 @@ fn do_work<F: Fn(&Analysis) -> T, T>(host: &AnalysisHost, work: F) -> T {
     {
         let start = Instant::now();
         eprint!("trivial change: ");
-        host.raw_database().salsa_runtime().next_revision();
+        host.raw_database().salsa_runtime().synthetic_write(Durability::LOW);
+        work(&host.analysis());
+        eprintln!("{:?}", start.elapsed());
+    }
+    {
+        let start = Instant::now();
+        eprint!("comment change: ");
+        {
+            let mut text = host.analysis().file_text(file_id).unwrap().to_string();
+            text.push_str("\n/* Hello world */\n");
+            let mut change = AnalysisChange::new();
+            change.change_file(file_id, Arc::new(text));
+            host.apply_change(change);
+        }
+        work(&host.analysis());
+        eprintln!("{:?}", start.elapsed());
+    }
+    {
+        let start = Instant::now();
+        eprint!("const change:   ");
+        host.raw_database().salsa_runtime().synthetic_write(Durability::HIGH);
         let res = work(&host.analysis());
         eprintln!("{:?}", start.elapsed());
         res
diff --git a/crates/ra_db/Cargo.toml b/crates/ra_db/Cargo.toml
index 7a13c247b..2fac07bc5 100644
--- a/crates/ra_db/Cargo.toml
+++ b/crates/ra_db/Cargo.toml
@@ -5,7 +5,7 @@ version = "0.1.0"
 authors = ["rust-analyzer developers"]
 
 [dependencies]
-salsa = "0.12.3"
+salsa = "0.13.0"
 relative-path = "0.4.0"
 rustc-hash = "1.0"
 
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 358365176..7b7974f5b 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,6 +1,5 @@
 use std::sync::Arc;
 
-use parking_lot::Mutex;
 use ra_db::{salsa, SourceDatabase};
 use ra_syntax::{ast, Parse, SmolStr, SyntaxNode};
 
@@ -147,6 +146,7 @@ pub trait DefDatabase: InternDatabase {
 }
 
 #[salsa::query_group(HirDatabaseStorage)]
+#[salsa::requires(salsa::Database)]
 pub trait HirDatabase: DefDatabase + AstDatabase {
     #[salsa::invoke(ExprScopes::expr_scopes_query)]
     fn expr_scopes(&self, def: DefWithBody) -> Arc<ExprScopes>;
@@ -187,11 +187,10 @@ pub trait HirDatabase: DefDatabase + AstDatabase {
     /// This provides the Chalk trait solver instance. Because Chalk always
     /// works from a specific crate, this query is keyed on the crate; and
     /// because Chalk does its own internal caching, the solver is wrapped in a
-    /// Mutex and the query is marked volatile, to make sure the cached state is
-    /// thrown away when input facts change.
+    /// Mutex and the query does an untracked read internally, to make sure the
+    /// cached state is thrown away when input facts change.
     #[salsa::invoke(crate::ty::traits::trait_solver_query)]
-    #[salsa::volatile]
-    fn trait_solver(&self, krate: Crate) -> Arc<Mutex<crate::ty::traits::Solver>>;
+    fn trait_solver(&self, krate: Crate) -> crate::ty::traits::TraitSolver;
 
     #[salsa::invoke(crate::ty::traits::chalk::associated_ty_data_query)]
     fn associated_ty_data(&self, id: chalk_ir::TypeId) -> Arc<chalk_rust_ir::AssociatedTyDatum>;
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 081974e2b..018fcd096 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -1,3 +1,5 @@
+#![recursion_limit = "512"]
+
 //! HIR (previously known as descriptors) provides a high-level object oriented
 //! access to Rust code.
 //!
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index fde5d8a47..b634f0b79 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -4,6 +4,7 @@ use std::sync::Arc;
 use chalk_ir::cast::Cast;
 use log::debug;
 use parking_lot::Mutex;
+use ra_db::salsa;
 use ra_prof::profile;
 use rustc_hash::FxHashSet;
 
@@ -14,7 +15,34 @@ use self::chalk::{from_chalk, ToChalk};
 
 pub(crate) mod chalk;
 
-pub(crate) type Solver = chalk_solve::Solver;
+#[derive(Debug, Clone)]
+pub struct TraitSolver {
+    krate: Crate,
+    inner: Arc<Mutex<chalk_solve::Solver>>,
+}
+
+/// We need eq for salsa
+impl PartialEq for TraitSolver {
+    fn eq(&self, other: &TraitSolver) -> bool {
+        Arc::ptr_eq(&self.inner, &other.inner)
+    }
+}
+
+impl Eq for TraitSolver {}
+
+impl TraitSolver {
+    fn solve(
+        &self,
+        db: &impl HirDatabase,
+        goal: &chalk_ir::UCanonical<chalk_ir::InEnvironment<chalk_ir::Goal>>,
+    ) -> Option<chalk_solve::Solution> {
+        let context = ChalkContext { db, krate: self.krate };
+        debug!("solve goal: {:?}", goal);
+        let solution = self.inner.lock().solve(&context, goal);
+        debug!("solve({:?}) => {:?}", goal, solution);
+        solution
+    }
+}
 
 /// This controls the maximum size of types Chalk considers. If we set this too
 /// high, we can run into slow edge cases; if we set it too low, Chalk won't
@@ -27,11 +55,15 @@ struct ChalkContext<'a, DB> {
     krate: Crate,
 }
 
-pub(crate) fn trait_solver_query(_db: &impl HirDatabase, _krate: Crate) -> Arc<Mutex<Solver>> {
+pub(crate) fn trait_solver_query(
+    db: &(impl HirDatabase + salsa::Database),
+    krate: Crate,
+) -> TraitSolver {
+    db.salsa_runtime().report_untracked_read();
     // krate parameter is just so we cache a unique solver per crate
     let solver_choice = chalk_solve::SolverChoice::SLG { max_size: CHALK_SOLVER_MAX_SIZE };
-    debug!("Creating new solver for crate {:?}", _krate);
-    Arc::new(Mutex::new(solver_choice.into_solver()))
+    debug!("Creating new solver for crate {:?}", krate);
+    TraitSolver { krate, inner: Arc::new(Mutex::new(solver_choice.into_solver())) }
 }
 
 /// Collects impls for the given trait in the whole dependency tree of `krate`.
@@ -54,18 +86,6 @@ pub(crate) fn impls_for_trait_query(
     impls.into_iter().collect::<Vec<_>>().into()
 }
 
-fn solve(
-    db: &impl HirDatabase,
-    krate: Crate,
-    goal: &chalk_ir::UCanonical<chalk_ir::InEnvironment<chalk_ir::Goal>>,
-) -> Option<chalk_solve::Solution> {
-    let context = ChalkContext { db, krate };
-    let solver = db.trait_solver(krate);
-    let solution = solver.lock().solve(&context, goal);
-    debug!("solve({:?}) => {:?}", goal, solution);
-    solution
-}
-
 /// A set of clauses that we assume to be true. E.g. if we are inside this function:
 /// ```rust
 /// fn foo<T: Default>(t: T) {}
@@ -127,7 +147,7 @@ pub(crate) fn trait_solve_query(
     // We currently don't deal with universes (I think / hope they're not yet
     // relevant for our use cases?)
     let u_canonical = chalk_ir::UCanonical { canonical, universes: 1 };
-    let solution = solve(db, krate, &u_canonical);
+    let solution = db.trait_solver(krate).solve(db, &u_canonical);
     solution.map(|solution| solution_from_chalk(db, solution))
 }
 
diff --git a/crates/ra_ide_api/src/change.rs b/crates/ra_ide_api/src/change.rs
index 147d2b21d..0234c572d 100644
--- a/crates/ra_ide_api/src/change.rs
+++ b/crates/ra_ide_api/src/change.rs
@@ -1,7 +1,7 @@
 use std::{fmt, sync::Arc, time};
 
 use ra_db::{
-    salsa::{Database, SweepStrategy},
+    salsa::{Database, Durability, SweepStrategy},
     CrateGraph, FileId, SourceDatabase, SourceRoot, SourceRootId,
 };
 use ra_prof::{memory_usage, profile, Bytes};
@@ -155,54 +155,71 @@ impl RootDatabase {
         log::info!("apply_change {:?}", change);
         {
             let _p = profile("RootDatabase::apply_change/cancellation");
-            self.salsa_runtime().next_revision();
+            self.salsa_runtime().synthetic_write(Durability::LOW);
         }
         if !change.new_roots.is_empty() {
             let mut local_roots = Vec::clone(&self.local_roots());
             for (root_id, is_local) in change.new_roots {
                 let root = if is_local { SourceRoot::new() } else { SourceRoot::new_library() };
-                self.set_source_root(root_id, Arc::new(root));
+                let durability = durability(&root);
+                self.set_source_root_with_durability(root_id, Arc::new(root), durability);
                 if is_local {
                     local_roots.push(root_id);
                 }
             }
-            self.set_local_roots(Arc::new(local_roots));
+            self.set_local_roots_with_durability(Arc::new(local_roots), Durability::HIGH);
         }
 
         for (root_id, root_change) in change.roots_changed {
             self.apply_root_change(root_id, root_change);
         }
         for (file_id, text) in change.files_changed {
-            self.set_file_text(file_id, text)
+            let source_root_id = self.file_source_root(file_id);
+            let source_root = self.source_root(source_root_id);
+            let durability = durability(&source_root);
+            self.set_file_text_with_durability(file_id, text, durability)
         }
         if !change.libraries_added.is_empty() {
             let mut libraries = Vec::clone(&self.library_roots());
             for library in change.libraries_added {
                 libraries.push(library.root_id);
-                self.set_source_root(library.root_id, Default::default());
-                self.set_constant_library_symbols(library.root_id, Arc::new(library.symbol_index));
+                self.set_source_root_with_durability(
+                    library.root_id,
+                    Default::default(),
+                    Durability::HIGH,
+                );
+                self.set_library_symbols_with_durability(
+                    library.root_id,
+                    Arc::new(library.symbol_index),
+                    Durability::HIGH,
+                );
                 self.apply_root_change(library.root_id, library.root_change);
             }
-            self.set_library_roots(Arc::new(libraries));
+            self.set_library_roots_with_durability(Arc::new(libraries), Durability::HIGH);
         }
         if let Some(crate_graph) = change.crate_graph {
-            self.set_crate_graph(Arc::new(crate_graph))
+            self.set_crate_graph_with_durability(Arc::new(crate_graph), Durability::HIGH)
         }
     }
 
     fn apply_root_change(&mut self, root_id: SourceRootId, root_change: RootChange) {
         let mut source_root = SourceRoot::clone(&self.source_root(root_id));
+        let durability = durability(&source_root);
         for add_file in root_change.added {
-            self.set_file_text(add_file.file_id, add_file.text);
-            self.set_file_relative_path(add_file.file_id, add_file.path.clone());
-            self.set_file_source_root(add_file.file_id, root_id);
+            self.set_file_text_with_durability(add_file.file_id, add_file.text, durability);
+            self.set_file_relative_path_with_durability(
+                add_file.file_id,
+                add_file.path.clone(),
+                durability,
+            );
+            self.set_file_source_root_with_durability(add_file.file_id, root_id, durability);
             source_root.files.insert(add_file.path, add_file.file_id);
         }
         for remove_file in root_change.removed {
-            self.set_file_text(remove_file.file_id, Default::default());
+            self.set_file_text_with_durability(remove_file.file_id, Default::default(), durability);
             source_root.files.remove(&remove_file.path);
         }
-        self.set_source_root(root_id, Arc::new(source_root));
+        self.set_source_root_with_durability(root_id, Arc::new(source_root), durability);
     }
 
     pub(crate) fn maybe_collect_garbage(&mut self) {
@@ -308,3 +325,11 @@ impl RootDatabase {
         acc
     }
 }
+
+fn durability(source_root: &SourceRoot) -> Durability {
+    if source_root.is_library {
+        Durability::HIGH
+    } else {
+        Durability::LOW
+    }
+}
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide_api/src/db.rs
index 44216b045..fc8252e4b 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide_api/src/db.rs
@@ -1,7 +1,7 @@
 use std::{sync::Arc, time};
 
 use ra_db::{
-    salsa::{self, Database},
+    salsa::{self, Database, Durability},
     Canceled, CheckCanceled, FileId, SourceDatabase,
 };
 
@@ -57,9 +57,9 @@ impl RootDatabase {
             last_gc: time::Instant::now(),
             last_gc_check: time::Instant::now(),
         };
-        db.set_crate_graph(Default::default());
-        db.set_local_roots(Default::default());
-        db.set_library_roots(Default::default());
+        db.set_crate_graph_with_durability(Default::default(), Durability::HIGH);
+        db.set_local_roots_with_durability(Default::default(), Durability::HIGH);
+        db.set_library_roots_with_durability(Default::default(), Durability::HIGH);
         let lru_capacity = lru_capacity.unwrap_or(ra_db::DEFAULT_LRU_CAP);
         db.query_mut(ra_db::ParseQuery).set_lru_capacity(lru_capacity);
         db.query_mut(hir::db::ParseMacroQuery).set_lru_capacity(lru_capacity);
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index edb646c11..fa4ae4379 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -281,6 +281,9 @@ impl AnalysisHost {
     pub fn raw_database(&self) -> &(impl hir::db::HirDatabase + salsa::Database) {
         &self.db
     }
+    pub fn raw_database_mut(&mut self) -> &mut (impl hir::db::HirDatabase + salsa::Database) {
+        &mut self.db
+    }
 }
 
 /// Analysis is a snapshot of a world state at a moment in time. It is the main
diff --git a/crates/ra_lsp_server/src/lib.rs b/crates/ra_lsp_server/src/lib.rs
index 795f86383..ca388e472 100644
--- a/crates/ra_lsp_server/src/lib.rs
+++ b/crates/ra_lsp_server/src/lib.rs
@@ -1,3 +1,4 @@
+#![recursion_limit = "512"]
 mod caps;
 mod cargo_target_spec;
 mod conv;
diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs
index 9fd3a235d..0495f34ae 100644
--- a/crates/ra_parser/src/grammar/expressions.rs
+++ b/crates/ra_parser/src/grammar/expressions.rs
@@ -359,11 +359,14 @@ fn lhs(
             return Some((m.complete(p, RANGE_EXPR), BlockLike::NotBlock));
         }
         _ => {
+            // test expression_after_block
+            // fn foo() {
+            //    let mut p = F{x: 5};
+            //    {p}.x = 10;
+            // }
+            //
             let (lhs, blocklike) = atom::atom_expr(p, r)?;
-            return Some((
-                postfix_expr(p, lhs, !(r.prefer_stmt && blocklike.is_block())),
-                blocklike,
-            ));
+            return Some(postfix_expr(p, lhs, blocklike, !(r.prefer_stmt && blocklike.is_block())));
         }
     };
     expr_bp(p, r, 255, dollar_lvl);
@@ -376,8 +379,9 @@ fn postfix_expr(
     // Calls are disallowed if the type is a block and we prefer statements because the call cannot be disambiguated from a tuple
     // E.g. `while true {break}();` is parsed as
     // `while true {break}; ();`
+    mut block_like: BlockLike,
     mut allow_calls: bool,
-) -> CompletedMarker {
+) -> (CompletedMarker, BlockLike) {
     loop {
         lhs = match p.current() {
             // test stmt_postfix_expr_ambiguity
@@ -417,9 +421,10 @@ fn postfix_expr(
             T![as] => cast_expr(p, lhs),
             _ => break,
         };
-        allow_calls = true
+        allow_calls = true;
+        block_like = BlockLike::NotBlock;
     }
-    lhs
+    (lhs, block_like)
 }
 
 // test call_expr
@@ -549,7 +554,7 @@ fn arg_list(p: &mut Parser) {
 //     let _ = format!();
 // }
 fn path_expr(p: &mut Parser, r: Restrictions) -> (CompletedMarker, BlockLike) {
-    assert!(paths::is_path_start(p) || p.at(T![<]));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::expr_path(p);
     match p.current() {
diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index d98953a7e..bc942ae01 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -62,7 +62,7 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
     if let Some(m) = literal(p) {
         return Some((m, BlockLike::NotBlock));
     }
-    if paths::is_path_start(p) || p.at(T![<]) {
+    if paths::is_path_start(p) {
         return Some(path_expr(p, r));
     }
     let la = p.nth(1);
@@ -110,7 +110,19 @@ pub(super) fn atom_expr(p: &mut Parser, r: Restrictions) -> Option<(CompletedMar
             p.bump();
             block_expr(p, Some(m))
         }
-        T!['{'] => block_expr(p, None),
+        T!['{'] => {
+            // test for_range_from
+            // fn foo() {
+            //    for x in 0 .. {
+            //        break;
+            //    }
+            // }
+            if r.forbid_structs {
+                return None;
+            } else {
+                block_expr(p, None)
+            }
+        }
         T![return] => return_expr(p),
         T![continue] => continue_expr(p),
         T![break] => break_expr(p, r),
diff --git a/crates/ra_parser/src/grammar/items.rs b/crates/ra_parser/src/grammar/items.rs
index 543af7c4b..b7da44758 100644
--- a/crates/ra_parser/src/grammar/items.rs
+++ b/crates/ra_parser/src/grammar/items.rs
@@ -49,7 +49,7 @@ pub(super) fn item_or_macro(p: &mut Parser, stop_on_r_curly: bool, flavor: ItemF
         }
         Err(m) => m,
     };
-    if paths::is_path_start(p) {
+    if paths::is_use_path_start(p) {
         match macro_call(p) {
             BlockLike::Block => (),
             BlockLike::NotBlock => {
@@ -378,7 +378,7 @@ pub(crate) fn mod_item_list(p: &mut Parser) {
 }
 
 fn macro_call(p: &mut Parser) -> BlockLike {
-    assert!(paths::is_path_start(p));
+    assert!(paths::is_use_path_start(p));
     paths::use_path(p);
     macro_call_after_excl(p)
 }
diff --git a/crates/ra_parser/src/grammar/items/use_item.rs b/crates/ra_parser/src/grammar/items/use_item.rs
index c3a0b4410..c0c7d0ec6 100644
--- a/crates/ra_parser/src/grammar/items/use_item.rs
+++ b/crates/ra_parser/src/grammar/items/use_item.rs
@@ -65,7 +65,7 @@ fn use_tree(p: &mut Parser) {
         // use crate::Item;
         // use self::some::Struct;
         // use crate_name::some_item;
-        _ if paths::is_path_start(p) => {
+        _ if paths::is_use_path_start(p) => {
             paths::use_path(p);
             match p.current() {
                 T![as] => {
diff --git a/crates/ra_parser/src/grammar/paths.rs b/crates/ra_parser/src/grammar/paths.rs
index 3537b0da1..07eb53b0c 100644
--- a/crates/ra_parser/src/grammar/paths.rs
+++ b/crates/ra_parser/src/grammar/paths.rs
@@ -4,6 +4,10 @@ pub(super) const PATH_FIRST: TokenSet =
     token_set![IDENT, SELF_KW, SUPER_KW, CRATE_KW, COLONCOLON, L_ANGLE];
 
 pub(super) fn is_path_start(p: &Parser) -> bool {
+    is_use_path_start(p) || p.at(T![<])
+}
+
+pub(super) fn is_use_path_start(p: &Parser) -> bool {
     match p.current() {
         IDENT | T![self] | T![super] | T![crate] | T![::] => true,
         _ => false,
@@ -58,7 +62,7 @@ fn path_segment(p: &mut Parser, mode: Mode, first: bool) {
     if first && p.eat(T![<]) {
         types::type_(p);
         if p.eat(T![as]) {
-            if is_path_start(p) {
+            if is_use_path_start(p) {
                 types::path_type(p);
             } else {
                 p.error("expected a trait");
diff --git a/crates/ra_parser/src/grammar/patterns.rs b/crates/ra_parser/src/grammar/patterns.rs
index 46034942a..df6000707 100644
--- a/crates/ra_parser/src/grammar/patterns.rs
+++ b/crates/ra_parser/src/grammar/patterns.rs
@@ -65,7 +65,7 @@ fn atom_pat(p: &mut Parser, recovery_set: TokenSet) -> Option<CompletedMarker> {
     {
         return Some(bind_pat(p, true));
     }
-    if paths::is_path_start(p) {
+    if paths::is_use_path_start(p) {
         return Some(path_pat(p));
     }
 
@@ -118,7 +118,7 @@ fn literal_pat(p: &mut Parser) -> CompletedMarker {
 //     let Bar(..) = ();
 // }
 fn path_pat(p: &mut Parser) -> CompletedMarker {
-    assert!(paths::is_path_start(p));
+    assert!(paths::is_use_path_start(p));
     let m = p.start();
     paths::expr_path(p);
     let kind = match p.current() {
diff --git a/crates/ra_parser/src/grammar/type_params.rs b/crates/ra_parser/src/grammar/type_params.rs
index ef59b59d3..d739df727 100644
--- a/crates/ra_parser/src/grammar/type_params.rs
+++ b/crates/ra_parser/src/grammar/type_params.rs
@@ -101,7 +101,7 @@ fn type_bound(p: &mut Parser) -> bool {
     match p.current() {
         LIFETIME => p.bump(),
         T![for] => types::for_type(p),
-        _ if paths::is_path_start(p) => types::path_type_(p, false),
+        _ if paths::is_use_path_start(p) => types::path_type_(p, false),
         _ => {
             m.abandon(p);
             return false;
diff --git a/crates/ra_parser/src/grammar/types.rs b/crates/ra_parser/src/grammar/types.rs
index c0b722569..29d173305 100644
--- a/crates/ra_parser/src/grammar/types.rs
+++ b/crates/ra_parser/src/grammar/types.rs
@@ -29,7 +29,7 @@ fn type_with_bounds_cond(p: &mut Parser, allow_bounds: bool) {
         T![dyn ] => dyn_trait_type(p),
         // Some path types are not allowed to have bounds (no plus)
         T![<] => path_type_(p, allow_bounds),
-        _ if paths::is_path_start(p) => path_or_macro_type_(p, allow_bounds),
+        _ if paths::is_use_path_start(p) => path_or_macro_type_(p, allow_bounds),
         _ => {
             p.err_recover("expected type", TYPE_RECOVERY_SET);
         }
@@ -205,6 +205,7 @@ pub(super) fn for_binder(p: &mut Parser) {
 // type A = for<'a> fn() -> ();
 // fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
 // fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
+// fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
 pub(super) fn for_type(p: &mut Parser) {
     assert!(p.at(T![for]));
     let m = p.start();
@@ -251,7 +252,7 @@ pub(super) fn path_type(p: &mut Parser) {
 // type A = foo!();
 // type B = crate::foo!();
 fn path_or_macro_type_(p: &mut Parser, allow_bounds: bool) {
-    assert!(paths::is_path_start(p) || p.at(T![<]));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::type_path(p);
 
@@ -270,7 +271,7 @@ fn path_or_macro_type_(p: &mut Parser, allow_bounds: bool) {
 }
 
 pub(super) fn path_type_(p: &mut Parser, allow_bounds: bool) {
-    assert!(paths::is_path_start(p) || p.at(T![<]));
+    assert!(paths::is_path_start(p));
     let m = p.start();
     paths::type_path(p);
 
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
index 7cde5c532..d6774d438 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.rs
@@ -1,3 +1,4 @@
 type A = for<'a> fn() -> ();
 fn foo<T>(_t: &T) where for<'a> &'a T: Iterator {}
 fn bar<T>(_t: &T) where for<'a> &'a mut T: Iterator {}
+fn baz<T>(_t: &T) where for<'a> <&'a T as Baz>::Foo: Iterator {}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.txt b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.txt
index 599cf9452..c12ce4ddb 100644
--- a/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.txt
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0081_for_type.txt
@@ -1,4 +1,4 @@
-SOURCE_FILE@[0; 135)
+SOURCE_FILE@[0; 200)
   TYPE_ALIAS_DEF@[0; 28)
     TYPE_KW@[0; 4) "type"
     WHITESPACE@[4; 5) " "
@@ -157,3 +157,84 @@ SOURCE_FILE@[0; 135)
       L_CURLY@[132; 133) "{"
       R_CURLY@[133; 134) "}"
   WHITESPACE@[134; 135) "\n"
+  FN_DEF@[135; 199)
+    FN_KW@[135; 137) "fn"
+    WHITESPACE@[137; 138) " "
+    NAME@[138; 141)
+      IDENT@[138; 141) "baz"
+    TYPE_PARAM_LIST@[141; 144)
+      L_ANGLE@[141; 142) "<"
+      TYPE_PARAM@[142; 143)
+        NAME@[142; 143)
+          IDENT@[142; 143) "T"
+      R_ANGLE@[143; 144) ">"
+    PARAM_LIST@[144; 152)
+      L_PAREN@[144; 145) "("
+      PARAM@[145; 151)
+        BIND_PAT@[145; 147)
+          NAME@[145; 147)
+            IDENT@[145; 147) "_t"
+        COLON@[147; 148) ":"
+        WHITESPACE@[148; 149) " "
+        REFERENCE_TYPE@[149; 151)
+          AMP@[149; 150) "&"
+          PATH_TYPE@[150; 151)
+            PATH@[150; 151)
+              PATH_SEGMENT@[150; 151)
+                NAME_REF@[150; 151)
+                  IDENT@[150; 151) "T"
+      R_PAREN@[151; 152) ")"
+    WHITESPACE@[152; 153) " "
+    WHERE_CLAUSE@[153; 196)
+      WHERE_KW@[153; 158) "where"
+      WHITESPACE@[158; 159) " "
+      WHERE_PRED@[159; 196)
+        FOR_TYPE@[159; 186)
+          FOR_KW@[159; 162) "for"
+          TYPE_PARAM_LIST@[162; 166)
+            L_ANGLE@[162; 163) "<"
+            LIFETIME_PARAM@[163; 165)
+              LIFETIME@[163; 165) "\'a"
+            R_ANGLE@[165; 166) ">"
+          WHITESPACE@[166; 167) " "
+          PATH_TYPE@[167; 186)
+            PATH@[167; 186)
+              PATH@[167; 181)
+                PATH_SEGMENT@[167; 181)
+                  L_ANGLE@[167; 168) "<"
+                  REFERENCE_TYPE@[168; 173)
+                    AMP@[168; 169) "&"
+                    LIFETIME@[169; 171) "\'a"
+                    WHITESPACE@[171; 172) " "
+                    PATH_TYPE@[172; 173)
+                      PATH@[172; 173)
+                        PATH_SEGMENT@[172; 173)
+                          NAME_REF@[172; 173)
+                            IDENT@[172; 173) "T"
+                  WHITESPACE@[173; 174) " "
+                  AS_KW@[174; 176) "as"
+                  WHITESPACE@[176; 177) " "
+                  PATH_TYPE@[177; 180)
+                    PATH@[177; 180)
+                      PATH_SEGMENT@[177; 180)
+                        NAME_REF@[177; 180)
+                          IDENT@[177; 180) "Baz"
+                  R_ANGLE@[180; 181) ">"
+              COLONCOLON@[181; 183) "::"
+              PATH_SEGMENT@[183; 186)
+                NAME_REF@[183; 186)
+                  IDENT@[183; 186) "Foo"
+        COLON@[186; 187) ":"
+        WHITESPACE@[187; 188) " "
+        TYPE_BOUND_LIST@[188; 196)
+          TYPE_BOUND@[188; 196)
+            PATH_TYPE@[188; 196)
+              PATH@[188; 196)
+                PATH_SEGMENT@[188; 196)
+                  NAME_REF@[188; 196)
+                    IDENT@[188; 196) "Iterator"
+    WHITESPACE@[196; 197) " "
+    BLOCK@[197; 199)
+      L_CURLY@[197; 198) "{"
+      R_CURLY@[198; 199) "}"
+  WHITESPACE@[199; 200) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0138_expression_after_block.rs b/crates/ra_syntax/test_data/parser/inline/ok/0138_expression_after_block.rs
new file mode 100644
index 000000000..76007e3ee
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0138_expression_after_block.rs
@@ -0,0 +1,4 @@
+fn foo() {
+   let mut p = F{x: 5};
+   {p}.x = 10;
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0138_expression_after_block.txt b/crates/ra_syntax/test_data/parser/inline/ok/0138_expression_after_block.txt
new file mode 100644
index 000000000..08128f365
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0138_expression_after_block.txt
@@ -0,0 +1,65 @@
+SOURCE_FILE@[0; 52)
+  FN_DEF@[0; 51)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    BLOCK@[9; 51)
+      L_CURLY@[9; 10) "{"
+      WHITESPACE@[10; 14) "\n   "
+      LET_STMT@[14; 34)
+        LET_KW@[14; 17) "let"
+        WHITESPACE@[17; 18) " "
+        BIND_PAT@[18; 23)
+          MUT_KW@[18; 21) "mut"
+          WHITESPACE@[21; 22) " "
+          NAME@[22; 23)
+            IDENT@[22; 23) "p"
+        WHITESPACE@[23; 24) " "
+        EQ@[24; 25) "="
+        WHITESPACE@[25; 26) " "
+        STRUCT_LIT@[26; 33)
+          PATH@[26; 27)
+            PATH_SEGMENT@[26; 27)
+              NAME_REF@[26; 27)
+                IDENT@[26; 27) "F"
+          NAMED_FIELD_LIST@[27; 33)
+            L_CURLY@[27; 28) "{"
+            NAMED_FIELD@[28; 32)
+              NAME_REF@[28; 29)
+                IDENT@[28; 29) "x"
+              COLON@[29; 30) ":"
+              WHITESPACE@[30; 31) " "
+              LITERAL@[31; 32)
+                INT_NUMBER@[31; 32) "5"
+            R_CURLY@[32; 33) "}"
+        SEMI@[33; 34) ";"
+      WHITESPACE@[34; 38) "\n   "
+      EXPR_STMT@[38; 49)
+        BIN_EXPR@[38; 48)
+          FIELD_EXPR@[38; 43)
+            BLOCK_EXPR@[38; 41)
+              BLOCK@[38; 41)
+                L_CURLY@[38; 39) "{"
+                PATH_EXPR@[39; 40)
+                  PATH@[39; 40)
+                    PATH_SEGMENT@[39; 40)
+                      NAME_REF@[39; 40)
+                        IDENT@[39; 40) "p"
+                R_CURLY@[40; 41) "}"
+            DOT@[41; 42) "."
+            NAME_REF@[42; 43)
+              IDENT@[42; 43) "x"
+          WHITESPACE@[43; 44) " "
+          EQ@[44; 45) "="
+          WHITESPACE@[45; 46) " "
+          LITERAL@[46; 48)
+            INT_NUMBER@[46; 48) "10"
+        SEMI@[48; 49) ";"
+      WHITESPACE@[49; 50) "\n"
+      R_CURLY@[50; 51) "}"
+  WHITESPACE@[51; 52) "\n"
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0142_for_range_from.rs b/crates/ra_syntax/test_data/parser/inline/ok/0142_for_range_from.rs
new file mode 100644
index 000000000..af0d40a7a
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0142_for_range_from.rs
@@ -0,0 +1,5 @@
+fn foo() {
+   for x in 0 .. {
+       break;
+   }
+}
diff --git a/crates/ra_syntax/test_data/parser/inline/ok/0142_for_range_from.txt b/crates/ra_syntax/test_data/parser/inline/ok/0142_for_range_from.txt
new file mode 100644
index 000000000..9e5836233
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/inline/ok/0142_for_range_from.txt
@@ -0,0 +1,40 @@
+SOURCE_FILE@[0; 51)
+  FN_DEF@[0; 50)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    BLOCK@[9; 50)
+      L_CURLY@[9; 10) "{"
+      WHITESPACE@[10; 14) "\n   "
+      FOR_EXPR@[14; 48)
+        FOR_KW@[14; 17) "for"
+        WHITESPACE@[17; 18) " "
+        BIND_PAT@[18; 19)
+          NAME@[18; 19)
+            IDENT@[18; 19) "x"
+        WHITESPACE@[19; 20) " "
+        IN_KW@[20; 22) "in"
+        WHITESPACE@[22; 23) " "
+        RANGE_EXPR@[23; 27)
+          LITERAL@[23; 24)
+            INT_NUMBER@[23; 24) "0"
+          WHITESPACE@[24; 25) " "
+          DOTDOT@[25; 27) ".."
+        WHITESPACE@[27; 28) " "
+        BLOCK@[28; 48)
+          L_CURLY@[28; 29) "{"
+          WHITESPACE@[29; 37) "\n       "
+          EXPR_STMT@[37; 43)
+            BREAK_EXPR@[37; 42)
+              BREAK_KW@[37; 42) "break"
+            SEMI@[42; 43) ";"
+          WHITESPACE@[43; 47) "\n   "
+          R_CURLY@[47; 48) "}"
+      WHITESPACE@[48; 49) "\n"
+      R_CURLY@[49; 50) "}"
+  WHITESPACE@[50; 51) "\n"
diff --git a/crates/ra_syntax/test_data/parser/ok/0052_for_range_block.rs b/crates/ra_syntax/test_data/parser/ok/0052_for_range_block.rs
new file mode 100644
index 000000000..b51b19630
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0052_for_range_block.rs
@@ -0,0 +1,5 @@
+fn foo() {
+   for _x in 0 .. (0 .. {1 + 2}).sum::<u32>() {
+       break;
+   }
+}
diff --git a/crates/ra_syntax/test_data/parser/ok/0052_for_range_block.txt b/crates/ra_syntax/test_data/parser/ok/0052_for_range_block.txt
new file mode 100644
index 000000000..858f042c6
--- /dev/null
+++ b/crates/ra_syntax/test_data/parser/ok/0052_for_range_block.txt
@@ -0,0 +1,79 @@
+SOURCE_FILE@[0; 80)
+  FN_DEF@[0; 79)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    BLOCK@[9; 79)
+      L_CURLY@[9; 10) "{"
+      WHITESPACE@[10; 14) "\n   "
+      FOR_EXPR@[14; 77)
+        FOR_KW@[14; 17) "for"
+        WHITESPACE@[17; 18) " "
+        BIND_PAT@[18; 20)
+          NAME@[18; 20)
+            IDENT@[18; 20) "_x"
+        WHITESPACE@[20; 21) " "
+        IN_KW@[21; 23) "in"
+        WHITESPACE@[23; 24) " "
+        RANGE_EXPR@[24; 56)
+          LITERAL@[24; 25)
+            INT_NUMBER@[24; 25) "0"
+          WHITESPACE@[25; 26) " "
+          DOTDOT@[26; 28) ".."
+          WHITESPACE@[28; 29) " "
+          METHOD_CALL_EXPR@[29; 56)
+            PAREN_EXPR@[29; 43)
+              L_PAREN@[29; 30) "("
+              RANGE_EXPR@[30; 42)
+                LITERAL@[30; 31)
+                  INT_NUMBER@[30; 31) "0"
+                WHITESPACE@[31; 32) " "
+                DOTDOT@[32; 34) ".."
+                WHITESPACE@[34; 35) " "
+                BLOCK_EXPR@[35; 42)
+                  BLOCK@[35; 42)
+                    L_CURLY@[35; 36) "{"
+                    BIN_EXPR@[36; 41)
+                      LITERAL@[36; 37)
+                        INT_NUMBER@[36; 37) "1"
+                      WHITESPACE@[37; 38) " "
+                      PLUS@[38; 39) "+"
+                      WHITESPACE@[39; 40) " "
+                      LITERAL@[40; 41)
+                        INT_NUMBER@[40; 41) "2"
+                    R_CURLY@[41; 42) "}"
+              R_PAREN@[42; 43) ")"
+            DOT@[43; 44) "."
+            NAME_REF@[44; 47)
+              IDENT@[44; 47) "sum"
+            TYPE_ARG_LIST@[47; 54)
+              COLONCOLON@[47; 49) "::"
+              L_ANGLE@[49; 50) "<"
+              TYPE_ARG@[50; 53)
+                PATH_TYPE@[50; 53)
+                  PATH@[50; 53)
+                    PATH_SEGMENT@[50; 53)
+                      NAME_REF@[50; 53)
+                        IDENT@[50; 53) "u32"
+              R_ANGLE@[53; 54) ">"
+            ARG_LIST@[54; 56)
+              L_PAREN@[54; 55) "("
+              R_PAREN@[55; 56) ")"
+        WHITESPACE@[56; 57) " "
+        BLOCK@[57; 77)
+          L_CURLY@[57; 58) "{"
+          WHITESPACE@[58; 66) "\n       "
+          EXPR_STMT@[66; 72)
+            BREAK_EXPR@[66; 71)
+              BREAK_KW@[66; 71) "break"
+            SEMI@[71; 72) ";"
+          WHITESPACE@[72; 76) "\n   "
+          R_CURLY@[76; 77) "}"
+      WHITESPACE@[77; 78) "\n"
+      R_CURLY@[78; 79) "}"
+  WHITESPACE@[79; 80) "\n"