12 files changed, 602 insertions, 88 deletions

diff --git a/crates/ra_hir_ty/src/_match.rs b/crates/ra_hir_ty/src/_match.rs
index 688026a04..779e78574 100644
--- a/crates/ra_hir_ty/src/_match.rs
+++ b/crates/ra_hir_ty/src/_match.rs
@@ -235,10 +235,19 @@ impl From<PatId> for PatIdOrWild {
     }
 }
 
+impl From<&PatId> for PatIdOrWild {
+    fn from(pat_id: &PatId) -> Self {
+        Self::PatId(*pat_id)
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum MatchCheckErr {
     NotImplemented,
     MalformedMatchArm,
+    /// Used when type inference cannot resolve the type of
+    /// a pattern or expression.
+    Unknown,
 }
 
 /// The return type of `is_useful` is either an indication of usefulness
@@ -290,10 +299,14 @@ impl PatStack {
         Self::from_slice(&self.0[1..])
     }
 
-    fn replace_head_with<T: Into<PatIdOrWild> + Copy>(&self, pat_ids: &[T]) -> PatStack {
+    fn replace_head_with<I, T>(&self, pats: I) -> PatStack
+    where
+        I: Iterator<Item = T>,
+        T: Into<PatIdOrWild>,
+    {
         let mut patterns: PatStackInner = smallvec![];
-        for pat in pat_ids {
-            patterns.push((*pat).into());
+        for pat in pats {
+            patterns.push(pat.into());
         }
         for pat in &self.0[1..] {
             patterns.push(*pat);
@@ -330,7 +343,7 @@ impl PatStack {
                     return Err(MatchCheckErr::NotImplemented);
                 }
 
-                Some(self.replace_head_with(pat_ids))
+                Some(self.replace_head_with(pat_ids.iter()))
             }
             (Pat::Lit(lit_expr), Constructor::Bool(constructor_val)) => {
                 match cx.body.exprs[lit_expr] {
@@ -382,7 +395,7 @@ impl PatStack {
                                 new_patterns.push((*pat_id).into());
                             }
 
-                            Some(self.replace_head_with(&new_patterns))
+                            Some(self.replace_head_with(new_patterns.into_iter()))
                         } else {
                             return Err(MatchCheckErr::MalformedMatchArm);
                         }
@@ -390,13 +403,41 @@ impl PatStack {
                         // If there is no ellipsis in the tuple pattern, the number
                         // of patterns must equal the constructor arity.
                         if pat_ids.len() == constructor_arity {
-                            Some(self.replace_head_with(pat_ids))
+                            Some(self.replace_head_with(pat_ids.into_iter()))
                         } else {
                             return Err(MatchCheckErr::MalformedMatchArm);
                         }
                     }
                 }
             }
+            (Pat::Record { args: ref arg_patterns, .. }, Constructor::Enum(e)) => {
+                let pat_id = self.head().as_id().expect("we know this isn't a wild");
+                if !enum_variant_matches(cx, pat_id, *e) {
+                    None
+                } else {
+                    match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
+                        VariantData::Record(struct_field_arena) => {
+                            // Here we treat any missing fields in the record as the wild pattern, as
+                            // if the record has ellipsis. We want to do this here even if the
+                            // record does not contain ellipsis, because it allows us to continue
+                            // enforcing exhaustiveness for the rest of the match statement.
+                            //
+                            // Creating the diagnostic for the missing field in the pattern
+                            // should be done in a different diagnostic.
+                            let patterns = struct_field_arena.iter().map(|(_, struct_field)| {
+                                arg_patterns
+                                    .iter()
+                                    .find(|pat| pat.name == struct_field.name)
+                                    .map(|pat| PatIdOrWild::from(pat.pat))
+                                    .unwrap_or(PatIdOrWild::Wild)
+                            });
+
+                            Some(self.replace_head_with(patterns))
+                        }
+                        _ => return Err(MatchCheckErr::Unknown),
+                    }
+                }
+            }
             (Pat::Or(_), _) => return Err(MatchCheckErr::NotImplemented),
             (_, _) => return Err(MatchCheckErr::NotImplemented),
         };
@@ -655,8 +696,8 @@ impl Constructor {
             Constructor::Enum(e) => {
                 match cx.db.enum_data(e.parent).variants[e.local_id].variant_data.as_ref() {
                     VariantData::Tuple(struct_field_data) => struct_field_data.len(),
+                    VariantData::Record(struct_field_data) => struct_field_data.len(),
                     VariantData::Unit => 0,
-                    _ => return Err(MatchCheckErr::NotImplemented),
                 }
             }
         };
@@ -695,10 +736,10 @@ fn pat_constructor(cx: &MatchCheckCtx, pat: PatIdOrWild) -> MatchCheckResult<Opt
             Expr::Literal(Literal::Bool(val)) => Some(Constructor::Bool(val)),
             _ => return Err(MatchCheckErr::NotImplemented),
         },
-        Pat::TupleStruct { .. } | Pat::Path(_) => {
+        Pat::TupleStruct { .. } | Pat::Path(_) | Pat::Record { .. } => {
             let pat_id = pat.as_id().expect("we already know this pattern is not a wild");
             let variant_id =
-                cx.infer.variant_resolution_for_pat(pat_id).ok_or(MatchCheckErr::NotImplemented)?;
+                cx.infer.variant_resolution_for_pat(pat_id).ok_or(MatchCheckErr::Unknown)?;
             match variant_id {
                 VariantId::EnumVariantId(enum_variant_id) => {
                     Some(Constructor::Enum(enum_variant_id))
@@ -759,20 +800,22 @@ mod tests {
     pub(super) use insta::assert_snapshot;
     pub(super) use ra_db::fixture::WithFixture;
 
-    pub(super) use crate::test_db::TestDB;
+    pub(super) use crate::{diagnostics::MissingMatchArms, test_db::TestDB};
 
     pub(super) fn check_diagnostic_message(content: &str) -> String {
-        TestDB::with_single_file(content).0.diagnostics().0
+        TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().0
     }
 
     pub(super) fn check_diagnostic(content: &str) {
-        let diagnostic_count = TestDB::with_single_file(content).0.diagnostics().1;
+        let diagnostic_count =
+            TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().1;
 
         assert_eq!(1, diagnostic_count, "no diagnostic reported");
     }
 
     pub(super) fn check_no_diagnostic(content: &str) {
-        let diagnostic_count = TestDB::with_single_file(content).0.diagnostics().1;
+        let diagnostic_count =
+            TestDB::with_single_file(content).0.diagnostic::<MissingMatchArms>().1;
 
         assert_eq!(0, diagnostic_count, "expected no diagnostic, found one");
     }
@@ -1532,6 +1575,236 @@ mod tests {
     }
 
     #[test]
+    fn enum_record_no_arms() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                }
+            }
+        ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_missing_arms() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { foo: true } => (),
+                }
+            }
+        ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { foo: true } => (),
+                    Either::A { foo: false } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_missing_field_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::B;
+                match a {
+                    Either::A { } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+
+        // When `Either::A` is missing a struct member, we don't want
+        // to fire the missing match arm diagnostic. This should fire
+        // some other diagnostic.
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_missing_field_missing_match_arm() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::B;
+                match a {
+                    Either::A { } => (),
+                }
+            }
+        ";
+
+        // Even though `Either::A` is missing fields, we still want to fire
+        // the missing arm diagnostic here, since we know `Either::B` is missing.
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_no_diagnostic_wild() {
+        let content = r"
+            enum Either {
+                A { foo: bool },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { foo: _ } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_fields_out_of_order_missing_arm() {
+        let content = r"
+            enum Either {
+                A { foo: bool, bar: () },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { bar: (), foo: false } => (),
+                    Either::A { foo: true, bar: () } => (),
+                }
+            }
+        ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_fields_out_of_order_no_diagnostic() {
+        let content = r"
+            enum Either {
+                A { foo: bool, bar: () },
+                B,
+            }
+            fn test_fn() {
+                let a = Either::A { foo: true };
+                match a {
+                    Either::A { bar: (), foo: false } => (),
+                    Either::A { foo: true, bar: () } => (),
+                    Either::B => (),
+                }
+            }
+        ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_ellipsis_missing_arm() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 match Either::B {
+                     Either::A { foo: true, .. } => (),
+                     Either::B => (),
+                 }
+             }
+         ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_ellipsis_no_diagnostic() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 let a = Either::A { foo: true };
+                 match a {
+                     Either::A { foo: true, .. } => (),
+                     Either::A { foo: false, .. } => (),
+                     Either::B => (),
+                 }
+             }
+         ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_ellipsis_all_fields_missing_arm() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 let a = Either::B;
+                 match a {
+                     Either::A { .. } => (),
+                 }
+             }
+         ";
+
+        check_diagnostic(content);
+    }
+
+    #[test]
+    fn enum_record_ellipsis_all_fields_no_diagnostic() {
+        let content = r"
+             enum Either {
+                 A { foo: bool, bar: bool },
+                 B,
+             }
+             fn test_fn() {
+                 let a = Either::B;
+                 match a {
+                     Either::A { .. } => (),
+                     Either::B => (),
+                 }
+             }
+         ";
+
+        check_no_diagnostic(content);
+    }
+
+    #[test]
     fn enum_tuple_partial_ellipsis_no_diagnostic() {
         let content = r"
             enum Either {
@@ -1689,25 +1962,6 @@ mod false_negatives {
     }
 
     #[test]
-    fn enum_record() {
-        let content = r"
-            enum Either {
-                A { foo: u32 },
-                B,
-            }
-            fn test_fn() {
-                match Either::B {
-                    Either::A { foo: 5 } => (),
-                }
-            }
-        ";
-
-        // This is a false negative.
-        // We don't currently handle enum record types.
-        check_no_diagnostic(content);
-    }
-
-    #[test]
     fn internal_or() {
         let content = r"
             fn test_fn() {
@@ -1796,4 +2050,22 @@ mod false_negatives {
         // We don't currently handle tuple patterns with ellipsis.
         check_no_diagnostic(content);
     }
+
+    #[test]
+    fn struct_missing_arm() {
+        let content = r"
+            struct Foo {
+                a: bool,
+            }
+            fn test_fn(f: Foo) {
+                match f {
+                    Foo { a: true } => {},
+                }
+            }
+        ";
+
+        // This is a false negative.
+        // We don't currently handle structs.
+        check_no_diagnostic(content);
+    }
 }
diff --git a/crates/ra_hir_ty/src/db.rs b/crates/ra_hir_ty/src/db.rs
index 33da16b48..9e5dfeab3 100644
--- a/crates/ra_hir_ty/src/db.rs
+++ b/crates/ra_hir_ty/src/db.rs
@@ -107,6 +107,13 @@ pub trait HirDatabase: DefDatabase + Upcast<dyn DefDatabase> {
         krate: CrateId,
         goal: crate::Canonical<crate::InEnvironment<crate::Obligation>>,
     ) -> Option<crate::traits::Solution>;
+
+    #[salsa::invoke(crate::traits::chalk::program_clauses_for_chalk_env_query)]
+    fn program_clauses_for_chalk_env(
+        &self,
+        krate: CrateId,
+        env: chalk_ir::Environment<chalk::Interner>,
+    ) -> chalk_ir::ProgramClauses<chalk::Interner>;
 }
 
 fn infer_wait(db: &impl HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
diff --git a/crates/ra_hir_ty/src/infer.rs b/crates/ra_hir_ty/src/infer.rs
index b6d9b3438..dfb6a435f 100644
--- a/crates/ra_hir_ty/src/infer.rs
+++ b/crates/ra_hir_ty/src/infer.rs
@@ -127,6 +127,7 @@ pub struct InferenceResult {
     field_resolutions: FxHashMap<ExprId, StructFieldId>,
     /// For each field in record literal, records the field it resolves to.
     record_field_resolutions: FxHashMap<ExprId, StructFieldId>,
+    record_field_pat_resolutions: FxHashMap<PatId, StructFieldId>,
     /// For each struct literal, records the variant it resolves to.
     variant_resolutions: FxHashMap<ExprOrPatId, VariantId>,
     /// For each associated item record what it resolves to
@@ -147,6 +148,9 @@ impl InferenceResult {
     pub fn record_field_resolution(&self, expr: ExprId) -> Option<StructFieldId> {
         self.record_field_resolutions.get(&expr).copied()
     }
+    pub fn record_field_pat_resolution(&self, pat: PatId) -> Option<StructFieldId> {
+        self.record_field_pat_resolutions.get(&pat).copied()
+    }
     pub fn variant_resolution_for_expr(&self, id: ExprId) -> Option<VariantId> {
         self.variant_resolutions.get(&id.into()).copied()
     }
diff --git a/crates/ra_hir_ty/src/infer/pat.rs b/crates/ra_hir_ty/src/infer/pat.rs
index 8ec4d4ace..7c2ad4384 100644
--- a/crates/ra_hir_ty/src/infer/pat.rs
+++ b/crates/ra_hir_ty/src/infer/pat.rs
@@ -7,6 +7,7 @@ use hir_def::{
     expr::{BindingAnnotation, Pat, PatId, RecordFieldPat},
     path::Path,
     type_ref::Mutability,
+    StructFieldId,
 };
 use hir_expand::name::Name;
 use test_utils::tested_by;
@@ -67,6 +68,11 @@ impl<'a> InferenceContext<'a> {
         let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default();
         for subpat in subpats {
             let matching_field = var_data.as_ref().and_then(|it| it.field(&subpat.name));
+            if let Some(local_id) = matching_field {
+                let field_def = StructFieldId { parent: def.unwrap(), local_id };
+                self.result.record_field_pat_resolutions.insert(subpat.pat, field_def);
+            }
+
             let expected_ty =
                 matching_field.map_or(Ty::Unknown, |field| field_tys[field].clone().subst(&substs));
             let expected_ty = self.normalize_associated_types_in(expected_ty);
diff --git a/crates/ra_hir_ty/src/lib.rs b/crates/ra_hir_ty/src/lib.rs
index a4b8d6683..279c06d65 100644
--- a/crates/ra_hir_ty/src/lib.rs
+++ b/crates/ra_hir_ty/src/lib.rs
@@ -863,7 +863,7 @@ pub trait TypeWalk {
             &mut |ty, binders| {
                 if let &mut Ty::Bound(bound) = ty {
                     if bound.debruijn >= binders {
-                        *ty = substs.0[bound.index].clone();
+                        *ty = substs.0[bound.index].clone().shift_bound_vars(binders);
                     }
                 }
             },
diff --git a/crates/ra_hir_ty/src/test_db.rs b/crates/ra_hir_ty/src/test_db.rs
index 3a4d58bf9..8498d3d96 100644
--- a/crates/ra_hir_ty/src/test_db.rs
+++ b/crates/ra_hir_ty/src/test_db.rs
@@ -12,7 +12,7 @@ use ra_db::{
 };
 use stdx::format_to;
 
-use crate::{db::HirDatabase, expr::ExprValidator};
+use crate::{db::HirDatabase, diagnostics::Diagnostic, expr::ExprValidator};
 
 #[salsa::database(
     ra_db::SourceDatabaseExtStorage,
@@ -104,10 +104,7 @@ impl TestDB {
         panic!("Can't find module for file")
     }
 
-    // FIXME: don't duplicate this
-    pub fn diagnostics(&self) -> (String, u32) {
-        let mut buf = String::new();
-        let mut count = 0;
+    fn diag<F: FnMut(&dyn Diagnostic)>(&self, mut cb: F) {
         let crate_graph = self.crate_graph();
         for krate in crate_graph.iter() {
             let crate_def_map = self.crate_def_map(krate);
@@ -132,15 +129,36 @@ impl TestDB {
 
             for f in fns {
                 let infer = self.infer(f.into());
-                let mut sink = DiagnosticSink::new(|d| {
-                    format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
-                    count += 1;
-                });
+                let mut sink = DiagnosticSink::new(&mut cb);
                 infer.add_diagnostics(self, f, &mut sink);
                 let mut validator = ExprValidator::new(f, infer, &mut sink);
                 validator.validate_body(self);
             }
         }
+    }
+
+    pub fn diagnostics(&self) -> (String, u32) {
+        let mut buf = String::new();
+        let mut count = 0;
+        self.diag(|d| {
+            format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
+            count += 1;
+        });
+        (buf, count)
+    }
+
+    /// Like `diagnostics`, but filtered for a single diagnostic.
+    pub fn diagnostic<D: Diagnostic>(&self) -> (String, u32) {
+        let mut buf = String::new();
+        let mut count = 0;
+        self.diag(|d| {
+            // We want to filter diagnostics by the particular one we are testing for, to
+            // avoid surprising results in tests.
+            if d.downcast_ref::<D>().is_some() {
+                format_to!(buf, "{:?}: {}\n", d.syntax_node(self).text(), d.message());
+                count += 1;
+            };
+        });
         (buf, count)
     }
 }
diff --git a/crates/ra_hir_ty/src/tests.rs b/crates/ra_hir_ty/src/tests.rs
index 81fc0f63a..846005baa 100644
--- a/crates/ra_hir_ty/src/tests.rs
+++ b/crates/ra_hir_ty/src/tests.rs
@@ -18,16 +18,19 @@ use hir_def::{
     nameres::CrateDefMap,
     AssocItemId, DefWithBodyId, LocalModuleId, Lookup, ModuleDefId,
 };
-use hir_expand::InFile;
+use hir_expand::{db::AstDatabase, InFile};
 use insta::assert_snapshot;
 use ra_db::{fixture::WithFixture, salsa::Database, FilePosition, SourceDatabase};
 use ra_syntax::{
     algo,
     ast::{self, AstNode},
+    SyntaxNode,
 };
 use stdx::format_to;
 
-use crate::{db::HirDatabase, display::HirDisplay, test_db::TestDB, InferenceResult};
+use crate::{
+    db::HirDatabase, display::HirDisplay, infer::TypeMismatch, test_db::TestDB, InferenceResult, Ty,
+};
 
 // These tests compare the inference results for all expressions in a file
 // against snapshots of the expected results using insta. Use cargo-insta to
@@ -67,13 +70,19 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
 
     let mut infer_def = |inference_result: Arc<InferenceResult>,
                          body_source_map: Arc<BodySourceMap>| {
-        let mut types = Vec::new();
-        let mut mismatches = Vec::new();
+        let mut types: Vec<(InFile<SyntaxNode>, &Ty)> = Vec::new();
+        let mut mismatches: Vec<(InFile<SyntaxNode>, &TypeMismatch)> = Vec::new();
 
         for (pat, ty) in inference_result.type_of_pat.iter() {
             let syntax_ptr = match body_source_map.pat_syntax(pat) {
                 Ok(sp) => {
-                    sp.map(|ast| ast.either(|it| it.syntax_node_ptr(), |it| it.syntax_node_ptr()))
+                    let root = db.parse_or_expand(sp.file_id).unwrap();
+                    sp.map(|ptr| {
+                        ptr.either(
+                            |it| it.to_node(&root).syntax().clone(),
+                            |it| it.to_node(&root).syntax().clone(),
+                        )
+                    })
                 }
                 Err(SyntheticSyntax) => continue,
             };
@@ -81,29 +90,31 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
         }
 
         for (expr, ty) in inference_result.type_of_expr.iter() {
-            let syntax_ptr = match body_source_map.expr_syntax(expr) {
-                Ok(sp) => sp.map(|ast| ast.syntax_node_ptr()),
+            let node = match body_source_map.expr_syntax(expr) {
+                Ok(sp) => {
+                    let root = db.parse_or_expand(sp.file_id).unwrap();
+                    sp.map(|ptr| ptr.to_node(&root).syntax().clone())
+                }
                 Err(SyntheticSyntax) => continue,
             };
-            types.push((syntax_ptr.clone(), ty));
+            types.push((node.clone(), ty));
             if let Some(mismatch) = inference_result.type_mismatch_for_expr(expr) {
-                mismatches.push((syntax_ptr, mismatch));
+                mismatches.push((node, mismatch));
             }
         }
 
         // sort ranges for consistency
-        types.sort_by_key(|(src_ptr, _)| {
-            (src_ptr.value.range().start(), src_ptr.value.range().end())
+        types.sort_by_key(|(node, _)| {
+            let range = node.value.text_range();
+            (range.start(), range.end())
         });
-        for (src_ptr, ty) in &types {
-            let node = src_ptr.value.to_node(&src_ptr.file_syntax(&db));
-
-            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.clone()) {
+        for (node, ty) in &types {
+            let (range, text) = if let Some(self_param) = ast::SelfParam::cast(node.value.clone()) {
                 (self_param.self_token().unwrap().text_range(), "self".to_string())
             } else {
-                (src_ptr.value.range(), node.text().to_string().replace("\n", " "))
+                (node.value.text_range(), node.value.text().to_string().replace("\n", " "))
             };
-            let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
+            let macro_prefix = if node.file_id != file_id.into() { "!" } else { "" };
             format_to!(
                 buf,
                 "{}{} '{}': {}\n",
@@ -114,11 +125,12 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
             );
         }
         if include_mismatches {
-            mismatches.sort_by_key(|(src_ptr, _)| {
-                (src_ptr.value.range().start(), src_ptr.value.range().end())
+            mismatches.sort_by_key(|(node, _)| {
+                let range = node.value.text_range();
+                (range.start(), range.end())
             });
             for (src_ptr, mismatch) in &mismatches {
-                let range = src_ptr.value.range();
+                let range = src_ptr.value.text_range();
                 let macro_prefix = if src_ptr.file_id != file_id.into() { "!" } else { "" };
                 format_to!(
                     buf,
diff --git a/crates/ra_hir_ty/src/tests/patterns.rs b/crates/ra_hir_ty/src/tests/patterns.rs
index 07cbc521a..6ea51d5d3 100644
--- a/crates/ra_hir_ty/src/tests/patterns.rs
+++ b/crates/ra_hir_ty/src/tests/patterns.rs
@@ -455,3 +455,29 @@ fn test() {
     "###
     );
 }
+
+#[test]
+fn infer_guard() {
+    assert_snapshot!(
+        infer(r#"
+struct S;
+impl S { fn foo(&self) -> bool { false } }
+
+fn main() {
+    match S {
+        s if s.foo() => (),
+    }
+}
+    "#), @"
+        [28; 32) 'self': &S
+        [42; 51) '{ false }': bool
+        [44; 49) 'false': bool
+        [65; 116) '{     ...   } }': ()
+        [71; 114) 'match ...     }': ()
+        [77; 78) 'S': S
+        [89; 90) 's': S
+        [94; 95) 's': S
+        [94; 101) 's.foo()': bool
+        [105; 107) '()': ()
+    ")
+}
diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 61284d672..61a6801fc 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -533,3 +533,44 @@ fn foo(b: Bar) {
     "###
     );
 }
+
+#[test]
+fn issue_4053_diesel_where_clauses() {
+    assert_snapshot!(
+        infer(r#"
+trait BoxedDsl<DB> {
+    type Output;
+    fn internal_into_boxed(self) -> Self::Output;
+}
+
+struct SelectStatement<From, Select, Distinct, Where, Order, LimitOffset, GroupBy, Locking> {
+    order: Order,
+}
+
+trait QueryFragment<DB: Backend> {}
+
+trait Into<T> { fn into(self) -> T; }
+
+impl<F, S, D, W, O, LOf, DB> BoxedDsl<DB>
+    for SelectStatement<F, S, D, W, O, LOf, G>
+where
+    O: Into<dyn QueryFragment<DB>>,
+{
+    type Output = XXX;
+
+    fn internal_into_boxed(self) -> Self::Output {
+        self.order.into();
+    }
+}
+"#),
+        @r###"
+    [66; 70) 'self': Self
+    [268; 272) 'self': Self
+    [467; 471) 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
+    [489; 523) '{     ...     }': ()
+    [499; 503) 'self': SelectStatement<F, S, D, W, O, LOf, {unknown}, {unknown}>
+    [499; 509) 'self.order': O
+    [499; 516) 'self.o...into()': dyn QueryFragment<DB>
+    "###
+    );
+}
diff --git a/crates/ra_hir_ty/src/traits.rs b/crates/ra_hir_ty/src/traits.rs
index 05791a848..6bc6d474c 100644
--- a/crates/ra_hir_ty/src/traits.rs
+++ b/crates/ra_hir_ty/src/traits.rs
@@ -225,7 +225,7 @@ fn solution_from_chalk(
                 None => unimplemented!(),
             })
             .collect();
-        let result = Canonical { value, num_vars: subst.binders.len() };
+        let result = Canonical { value, num_vars: subst.binders.len(&Interner) };
         SolutionVariables(result)
     };
     match solution {
diff --git a/crates/ra_hir_ty/src/traits/chalk.rs b/crates/ra_hir_ty/src/traits/chalk.rs
index e00a82db2..1ccb7c3b4 100644
--- a/crates/ra_hir_ty/src/traits/chalk.rs
+++ b/crates/ra_hir_ty/src/traits/chalk.rs
@@ -4,8 +4,8 @@ use std::{fmt, sync::Arc};
 use log::debug;
 
 use chalk_ir::{
-    cast::Cast, fold::shift::Shift, Goal, GoalData, Parameter, PlaceholderIndex, TypeName,
-    UniverseIndex,
+    cast::Cast, fold::shift::Shift, interner::HasInterner, Goal, GoalData, Parameter,
+    PlaceholderIndex, TypeName, UniverseIndex,
 };
 
 use hir_def::{AssocContainerId, AssocItemId, GenericDefId, HasModule, Lookup, TypeAliasId};
@@ -33,8 +33,10 @@ impl chalk_ir::interner::Interner for Interner {
     type InternedGoals = Vec<Goal<Self>>;
     type InternedSubstitution = Vec<Parameter<Self>>;
     type InternedProgramClause = chalk_ir::ProgramClauseData<Self>;
-    type InternedProgramClauses = Vec<chalk_ir::ProgramClause<Self>>;
+    type InternedProgramClauses = Arc<[chalk_ir::ProgramClause<Self>]>;
     type InternedQuantifiedWhereClauses = Vec<chalk_ir::QuantifiedWhereClause<Self>>;
+    type InternedParameterKinds = Vec<chalk_ir::ParameterKind<()>>;
+    type InternedCanonicalVarKinds = Vec<chalk_ir::ParameterKind<UniverseIndex>>;
     type Identifier = TypeAliasId;
     type DefId = InternId;
 
@@ -60,6 +62,27 @@ impl chalk_ir::interner::Interner for Interner {
         tls::with_current_program(|prog| Some(prog?.debug_alias(alias, fmt)))
     }
 
+    fn debug_projection_ty(
+        proj: &chalk_ir::ProjectionTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_projection_ty(proj, fmt)))
+    }
+
+    fn debug_opaque_ty(
+        opaque_ty: &chalk_ir::OpaqueTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_opaque_ty(opaque_ty, fmt)))
+    }
+
+    fn debug_opaque_ty_id(
+        opaque_ty_id: chalk_ir::OpaqueTyId<Self>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Option<fmt::Result> {
+        tls::with_current_program(|prog| Some(prog?.debug_opaque_ty_id(opaque_ty_id, fmt)))
+    }
+
     fn debug_ty(ty: &chalk_ir::Ty<Interner>, fmt: &mut fmt::Formatter<'_>) -> Option<fmt::Result> {
         tls::with_current_program(|prog| Some(prog?.debug_ty(ty, fmt)))
     }
@@ -202,15 +225,15 @@ impl chalk_ir::interner::Interner for Interner {
     fn intern_program_clauses(
         &self,
         data: impl IntoIterator<Item = chalk_ir::ProgramClause<Self>>,
-    ) -> Vec<chalk_ir::ProgramClause<Self>> {
+    ) -> Arc<[chalk_ir::ProgramClause<Self>]> {
         data.into_iter().collect()
     }
 
     fn program_clauses_data<'a>(
         &self,
-        clauses: &'a Vec<chalk_ir::ProgramClause<Self>>,
+        clauses: &'a Arc<[chalk_ir::ProgramClause<Self>]>,
     ) -> &'a [chalk_ir::ProgramClause<Self>] {
-        clauses
+        &clauses
     }
 
     fn intern_quantified_where_clauses(
@@ -226,6 +249,34 @@ impl chalk_ir::interner::Interner for Interner {
     ) -> &'a [chalk_ir::QuantifiedWhereClause<Self>] {
         clauses
     }
+
+    fn intern_parameter_kinds(
+        &self,
+        data: impl IntoIterator<Item = chalk_ir::ParameterKind<()>>,
+    ) -> Self::InternedParameterKinds {
+        data.into_iter().collect()
+    }
+
+    fn parameter_kinds_data<'a>(
+        &self,
+        parameter_kinds: &'a Self::InternedParameterKinds,
+    ) -> &'a [chalk_ir::ParameterKind<()>] {
+        &parameter_kinds
+    }
+
+    fn intern_canonical_var_kinds(
+        &self,
+        data: impl IntoIterator<Item = chalk_ir::ParameterKind<UniverseIndex>>,
+    ) -> Self::InternedCanonicalVarKinds {
+        data.into_iter().collect()
+    }
+
+    fn canonical_var_kinds_data<'a>(
+        &self,
+        canonical_var_kinds: &'a Self::InternedCanonicalVarKinds,
+    ) -> &'a [chalk_ir::ParameterKind<UniverseIndex>] {
+        &canonical_var_kinds
+    }
 }
 
 impl chalk_ir::interner::HasInterner for Interner {
@@ -268,9 +319,12 @@ impl ToChalk for Ty {
             Ty::Projection(proj_ty) => {
                 let associated_ty_id = proj_ty.associated_ty.to_chalk(db);
                 let substitution = proj_ty.parameters.to_chalk(db);
-                chalk_ir::AliasTy { associated_ty_id, substitution }
-                    .cast(&Interner)
-                    .intern(&Interner)
+                chalk_ir::AliasTy::Projection(chalk_ir::ProjectionTy {
+                    associated_ty_id,
+                    substitution,
+                })
+                .cast(&Interner)
+                .intern(&Interner)
             }
             Ty::Placeholder(id) => {
                 let interned_id = db.intern_type_param_id(id);
@@ -314,16 +368,17 @@ impl ToChalk for Ty {
                 );
                 Ty::Placeholder(db.lookup_intern_type_param_id(interned_id))
             }
-            chalk_ir::TyData::Alias(proj) => {
+            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Projection(proj)) => {
                 let associated_ty = from_chalk(db, proj.associated_ty_id);
                 let parameters = from_chalk(db, proj.substitution);
                 Ty::Projection(ProjectionTy { associated_ty, parameters })
             }
+            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(_)) => unimplemented!(),
             chalk_ir::TyData::Function(_) => unimplemented!(),
             chalk_ir::TyData::BoundVar(idx) => Ty::Bound(idx),
             chalk_ir::TyData::InferenceVar(_iv) => Ty::Unknown,
             chalk_ir::TyData::Dyn(where_clauses) => {
-                assert_eq!(where_clauses.bounds.binders.len(), 1);
+                assert_eq!(where_clauses.bounds.binders.len(&Interner), 1);
                 let predicates = where_clauses
                     .bounds
                     .skip_binders()
@@ -404,6 +459,7 @@ impl ToChalk for TypeCtor {
         match type_name {
             TypeName::Struct(struct_id) => db.lookup_intern_type_ctor(struct_id.into()),
             TypeName::AssociatedType(type_id) => TypeCtor::AssociatedType(from_chalk(db, type_id)),
+            TypeName::OpaqueType(_) => unreachable!(),
             TypeName::Error => {
                 // this should not be reached, since we don't represent TypeName::Error with TypeCtor
                 unreachable!()
@@ -460,7 +516,8 @@ impl ToChalk for GenericPredicate {
             }
             GenericPredicate::Projection(projection_pred) => {
                 let ty = projection_pred.ty.to_chalk(db).shifted_in(&Interner);
-                let alias = projection_pred.projection_ty.to_chalk(db).shifted_in(&Interner);
+                let projection = projection_pred.projection_ty.to_chalk(db).shifted_in(&Interner);
+                let alias = chalk_ir::AliasTy::Projection(projection);
                 make_binders(chalk_ir::WhereClause::AliasEq(chalk_ir::AliasEq { alias, ty }), 0)
             }
             GenericPredicate::Error => panic!("tried passing GenericPredicate::Error to Chalk"),
@@ -481,7 +538,13 @@ impl ToChalk for GenericPredicate {
                 GenericPredicate::Implemented(from_chalk(db, tr))
             }
             chalk_ir::WhereClause::AliasEq(projection_eq) => {
-                let projection_ty = from_chalk(db, projection_eq.alias);
+                let projection_ty = from_chalk(
+                    db,
+                    match projection_eq.alias {
+                        chalk_ir::AliasTy::Projection(p) => p,
+                        _ => unimplemented!(),
+                    },
+                );
                 let ty = from_chalk(db, projection_eq.ty);
                 GenericPredicate::Projection(super::ProjectionPredicate { projection_ty, ty })
             }
@@ -490,10 +553,10 @@ impl ToChalk for GenericPredicate {
 }
 
 impl ToChalk for ProjectionTy {
-    type Chalk = chalk_ir::AliasTy<Interner>;
+    type Chalk = chalk_ir::ProjectionTy<Interner>;
 
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasTy<Interner> {
-        chalk_ir::AliasTy {
+    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::ProjectionTy<Interner> {
+        chalk_ir::ProjectionTy {
             associated_ty_id: self.associated_ty.to_chalk(db),
             substitution: self.parameters.to_chalk(db),
         }
@@ -501,7 +564,7 @@ impl ToChalk for ProjectionTy {
 
     fn from_chalk(
         db: &dyn HirDatabase,
-        projection_ty: chalk_ir::AliasTy<Interner>,
+        projection_ty: chalk_ir::ProjectionTy<Interner>,
     ) -> ProjectionTy {
         ProjectionTy {
             associated_ty: from_chalk(db, projection_ty.associated_ty_id),
@@ -514,7 +577,10 @@ impl ToChalk for super::ProjectionPredicate {
     type Chalk = chalk_ir::AliasEq<Interner>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasEq<Interner> {
-        chalk_ir::AliasEq { alias: self.projection_ty.to_chalk(db), ty: self.ty.to_chalk(db) }
+        chalk_ir::AliasEq {
+            alias: chalk_ir::AliasTy::Projection(self.projection_ty.to_chalk(db)),
+            ty: self.ty.to_chalk(db),
+        }
     }
 
     fn from_chalk(_db: &dyn HirDatabase, _normalize: chalk_ir::AliasEq<Interner>) -> Self {
@@ -540,17 +606,24 @@ impl ToChalk for Obligation {
 impl<T> ToChalk for Canonical<T>
 where
     T: ToChalk,
+    T::Chalk: HasInterner<Interner = Interner>,
 {
     type Chalk = chalk_ir::Canonical<T::Chalk>;
 
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
         let parameter = chalk_ir::ParameterKind::Ty(chalk_ir::UniverseIndex::ROOT);
         let value = self.value.to_chalk(db);
-        chalk_ir::Canonical { value, binders: vec![parameter; self.num_vars] }
+        chalk_ir::Canonical {
+            value,
+            binders: chalk_ir::CanonicalVarKinds::from(&Interner, vec![parameter; self.num_vars]),
+        }
     }
 
     fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {
-        Canonical { num_vars: canonical.binders.len(), value: from_chalk(db, canonical.value) }
+        Canonical {
+            num_vars: canonical.binders.len(&Interner),
+            value: from_chalk(db, canonical.value),
+        }
     }
 }
 
@@ -649,9 +722,15 @@ impl ToChalk for builtin::BuiltinImplAssocTyValueData {
     }
 }
 
-fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T> {
+fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T>
+where
+    T: HasInterner<Interner = Interner>,
+{
     chalk_ir::Binders::new(
-        std::iter::repeat(chalk_ir::ParameterKind::Ty(())).take(num_vars).collect(),
+        chalk_ir::ParameterKinds::from(
+            &Interner,
+            std::iter::repeat(chalk_ir::ParameterKind::Ty(())).take(num_vars),
+        ),
         value,
     )
 }
@@ -799,6 +878,28 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         // FIXME tell Chalk about well-known traits (here and in trait_datum)
         None
     }
+
+    fn program_clauses_for_env(
+        &self,
+        environment: &chalk_ir::Environment<Interner>,
+    ) -> chalk_ir::ProgramClauses<Interner> {
+        self.db.program_clauses_for_chalk_env(self.krate, environment.clone())
+    }
+
+    fn opaque_ty_data(
+        &self,
+        _id: chalk_ir::OpaqueTyId<Interner>,
+    ) -> Arc<chalk_rust_ir::OpaqueTyDatum<Interner>> {
+        unimplemented!()
+    }
+}
+
+pub(crate) fn program_clauses_for_chalk_env_query(
+    db: &dyn HirDatabase,
+    krate: CrateId,
+    environment: chalk_ir::Environment<Interner>,
+) -> chalk_ir::ProgramClauses<Interner> {
+    chalk_solve::program_clauses_for_env(&ChalkContext { db, krate }, &environment)
 }
 
 pub(crate) fn associated_ty_data_query(
diff --git a/crates/ra_hir_ty/src/traits/chalk/tls.rs b/crates/ra_hir_ty/src/traits/chalk/tls.rs
index fa8e4d1ad..4867cb17e 100644
--- a/crates/ra_hir_ty/src/traits/chalk/tls.rs
+++ b/crates/ra_hir_ty/src/traits/chalk/tls.rs
@@ -121,19 +121,38 @@ impl DebugContext<'_> {
         write!(fmt, "{}::{}", trait_data.name, type_alias_data.name)
     }
 
+    pub fn debug_opaque_ty_id(
+        &self,
+        opaque_ty_id: chalk_ir::OpaqueTyId<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Result<(), fmt::Error> {
+        fmt.debug_struct("OpaqueTyId").field("index", &opaque_ty_id.0).finish()
+    }
+
     pub fn debug_alias(
         &self,
-        alias: &AliasTy<Interner>,
+        alias_ty: &AliasTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Result<(), fmt::Error> {
+        match alias_ty {
+            AliasTy::Projection(projection_ty) => self.debug_projection_ty(projection_ty, fmt),
+            AliasTy::Opaque(opaque_ty) => self.debug_opaque_ty(opaque_ty, fmt),
+        }
+    }
+
+    pub fn debug_projection_ty(
+        &self,
+        projection_ty: &chalk_ir::ProjectionTy<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        let type_alias: TypeAliasId = from_chalk(self.0, alias.associated_ty_id);
+        let type_alias: TypeAliasId = from_chalk(self.0, projection_ty.associated_ty_id);
         let type_alias_data = self.0.type_alias_data(type_alias);
         let trait_ = match type_alias.lookup(self.0.upcast()).container {
             AssocContainerId::TraitId(t) => t,
             _ => panic!("associated type not in trait"),
         };
         let trait_data = self.0.trait_data(trait_);
-        let params = alias.substitution.parameters(&Interner);
+        let params = projection_ty.substitution.parameters(&Interner);
         write!(fmt, "<{:?} as {}", &params[0], trait_data.name,)?;
         if params.len() > 1 {
             write!(
@@ -145,6 +164,14 @@ impl DebugContext<'_> {
         write!(fmt, ">::{}", type_alias_data.name)
     }
 
+    pub fn debug_opaque_ty(
+        &self,
+        opaque_ty: &chalk_ir::OpaqueTy<Interner>,
+        fmt: &mut fmt::Formatter<'_>,
+    ) -> Result<(), fmt::Error> {
+        write!(fmt, "{:?}", opaque_ty.opaque_ty_id)
+    }
+
     pub fn debug_ty(
         &self,
         ty: &chalk_ir::Ty<Interner>,