16 files changed, 610 insertions, 611 deletions

diff --git a/crates/hir_ty/src/diagnostics/decl_check.rs b/crates/hir_ty/src/diagnostics/decl_check.rs
index f179c62b7..4b3e2fa8f 100644
--- a/crates/hir_ty/src/diagnostics/decl_check.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check.rs
@@ -16,7 +16,7 @@ use hir_def::{
     adt::VariantData,
     expr::{Pat, PatId},
     src::HasSource,
-    AdtId, ConstId, EnumId, FunctionId, Lookup, ModuleDefId, StaticId, StructId,
+    AdtId, AttrDefId, ConstId, EnumId, FunctionId, Lookup, ModuleDefId, StaticId, StructId,
 };
 use hir_expand::{
     diagnostics::DiagnosticSink,
@@ -32,6 +32,12 @@ use crate::{
     diagnostics::{decl_check::case_conv::*, CaseType, IncorrectCase},
 };
 
+mod allow {
+    pub(super) const NON_SNAKE_CASE: &str = "non_snake_case";
+    pub(super) const NON_UPPER_CASE_GLOBAL: &str = "non_upper_case_globals";
+    pub(super) const NON_CAMEL_CASE_TYPES: &str = "non_camel_case_types";
+}
+
 pub(super) struct DeclValidator<'a, 'b: 'a> {
     owner: ModuleDefId,
     sink: &'a mut DiagnosticSink<'b>,
@@ -72,11 +78,29 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
         }
     }
 
+    /// Checks whether not following the convention is allowed for this item.
+    ///
+    /// Currently this method doesn't check parent attributes.
+    fn allowed(&self, db: &dyn HirDatabase, id: AttrDefId, allow_name: &str) -> bool {
+        db.attrs(id).by_key("allow").tt_values().any(|tt| tt.to_string().contains(allow_name))
+    }
+
     fn validate_func(&mut self, db: &dyn HirDatabase, func: FunctionId) {
         let data = db.function_data(func);
         let body = db.body(func.into());
 
-        // 1. Check the function name.
+        // Recursively validate inner scope items, such as static variables and constants.
+        for (item_id, _) in body.item_scope.values() {
+            let mut validator = DeclValidator::new(item_id, self.sink);
+            validator.validate_item(db);
+        }
+
+        // Check whether non-snake case identifiers are allowed for this function.
+        if self.allowed(db, func.into(), allow::NON_SNAKE_CASE) {
+            return;
+        }
+
+        // Check the function name.
         let function_name = data.name.to_string();
         let fn_name_replacement = if let Some(new_name) = to_lower_snake_case(&function_name) {
             let replacement = Replacement {
@@ -89,7 +113,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             None
         };
 
-        // 2. Check the param names.
+        // Check the param names.
         let mut fn_param_replacements = Vec::new();
 
         for pat_id in body.params.iter().cloned() {
@@ -111,7 +135,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             }
         }
 
-        // 3. Check the patterns inside the function body.
+        // Check the patterns inside the function body.
         let mut pats_replacements = Vec::new();
 
         for (pat_idx, pat) in body.pats.iter() {
@@ -136,7 +160,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             }
         }
 
-        // 4. If there is at least one element to spawn a warning on, go to the source map and generate a warning.
+        // If there is at least one element to spawn a warning on, go to the source map and generate a warning.
         self.create_incorrect_case_diagnostic_for_func(
             func,
             db,
@@ -144,12 +168,6 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             fn_param_replacements,
         );
         self.create_incorrect_case_diagnostic_for_variables(func, db, pats_replacements);
-
-        // 5. Recursively validate inner scope items, such as static variables and constants.
-        for (item_id, _) in body.item_scope.values() {
-            let mut validator = DeclValidator::new(item_id, self.sink);
-            validator.validate_item(db);
-        }
     }
 
     /// Given the information about incorrect names in the function declaration, looks up into the source code
@@ -169,7 +187,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
         let fn_loc = func.lookup(db.upcast());
         let fn_src = fn_loc.source(db.upcast());
 
-        // 1. Diagnostic for function name.
+        // Diagnostic for function name.
         if let Some(replacement) = fn_name_replacement {
             let ast_ptr = match fn_src.value.name() {
                 Some(name) => name,
@@ -196,7 +214,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             self.sink.push(diagnostic);
         }
 
-        // 2. Diagnostics for function params.
+        // Diagnostics for function params.
         let fn_params_list = match fn_src.value.param_list() {
             Some(params) => params,
             None => {
@@ -312,7 +330,11 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_struct(&mut self, db: &dyn HirDatabase, struct_id: StructId) {
         let data = db.struct_data(struct_id);
 
-        // 1. Check the structure name.
+        let non_camel_case_allowed =
+            self.allowed(db, struct_id.into(), allow::NON_CAMEL_CASE_TYPES);
+        let non_snake_case_allowed = self.allowed(db, struct_id.into(), allow::NON_SNAKE_CASE);
+
+        // Check the structure name.
         let struct_name = data.name.to_string();
         let struct_name_replacement = if let Some(new_name) = to_camel_case(&struct_name) {
             let replacement = Replacement {
@@ -320,29 +342,35 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
                 suggested_text: new_name,
                 expected_case: CaseType::UpperCamelCase,
             };
-            Some(replacement)
+            if non_camel_case_allowed {
+                None
+            } else {
+                Some(replacement)
+            }
         } else {
             None
         };
 
-        // 2. Check the field names.
+        // Check the field names.
         let mut struct_fields_replacements = Vec::new();
 
-        if let VariantData::Record(fields) = data.variant_data.as_ref() {
-            for (_, field) in fields.iter() {
-                let field_name = field.name.to_string();
-                if let Some(new_name) = to_lower_snake_case(&field_name) {
-                    let replacement = Replacement {
-                        current_name: field.name.clone(),
-                        suggested_text: new_name,
-                        expected_case: CaseType::LowerSnakeCase,
-                    };
-                    struct_fields_replacements.push(replacement);
+        if !non_snake_case_allowed {
+            if let VariantData::Record(fields) = data.variant_data.as_ref() {
+                for (_, field) in fields.iter() {
+                    let field_name = field.name.to_string();
+                    if let Some(new_name) = to_lower_snake_case(&field_name) {
+                        let replacement = Replacement {
+                            current_name: field.name.clone(),
+                            suggested_text: new_name,
+                            expected_case: CaseType::LowerSnakeCase,
+                        };
+                        struct_fields_replacements.push(replacement);
+                    }
                 }
             }
         }
 
-        // 3. If there is at least one element to spawn a warning on, go to the source map and generate a warning.
+        // If there is at least one element to spawn a warning on, go to the source map and generate a warning.
         self.create_incorrect_case_diagnostic_for_struct(
             struct_id,
             db,
@@ -442,7 +470,12 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_enum(&mut self, db: &dyn HirDatabase, enum_id: EnumId) {
         let data = db.enum_data(enum_id);
 
-        // 1. Check the enum name.
+        // Check whether non-camel case names are allowed for this enum.
+        if self.allowed(db, enum_id.into(), allow::NON_CAMEL_CASE_TYPES) {
+            return;
+        }
+
+        // Check the enum name.
         let enum_name = data.name.to_string();
         let enum_name_replacement = if let Some(new_name) = to_camel_case(&enum_name) {
             let replacement = Replacement {
@@ -455,7 +488,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             None
         };
 
-        // 2. Check the field names.
+        // Check the field names.
         let mut enum_fields_replacements = Vec::new();
 
         for (_, variant) in data.variants.iter() {
@@ -470,7 +503,7 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
             }
         }
 
-        // 3. If there is at least one element to spawn a warning on, go to the source map and generate a warning.
+        // If there is at least one element to spawn a warning on, go to the source map and generate a warning.
         self.create_incorrect_case_diagnostic_for_enum(
             enum_id,
             db,
@@ -572,6 +605,10 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_const(&mut self, db: &dyn HirDatabase, const_id: ConstId) {
         let data = db.const_data(const_id);
 
+        if self.allowed(db, const_id.into(), allow::NON_UPPER_CASE_GLOBAL) {
+            return;
+        }
+
         let name = match &data.name {
             Some(name) => name,
             None => return,
@@ -612,6 +649,10 @@ impl<'a, 'b> DeclValidator<'a, 'b> {
     fn validate_static(&mut self, db: &dyn HirDatabase, static_id: StaticId) {
         let data = db.static_data(static_id);
 
+        if self.allowed(db, static_id.into(), allow::NON_UPPER_CASE_GLOBAL) {
+            return;
+        }
+
         let name = match &data.name {
             Some(name) => name,
             None => return,
@@ -854,4 +895,29 @@ fn main() {
 "#,
         );
     }
+
+    #[test]
+    fn allow_attributes() {
+        check_diagnostics(
+            r#"
+            #[allow(non_snake_case)]
+    fn NonSnakeCaseName(SOME_VAR: u8) -> u8{
+        let OtherVar = SOME_VAR + 1;
+        OtherVar
+    }
+
+    #[allow(non_snake_case, non_camel_case_types)]
+    pub struct some_type {
+        SOME_FIELD: u8,
+        SomeField: u16,
+    }
+
+    #[allow(non_upper_case_globals)]
+    pub const some_const: u8 = 10;
+
+    #[allow(non_upper_case_globals)]
+    pub static SomeStatic: u8 = 10;
+    "#,
+        );
+    }
 }
diff --git a/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs b/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs
index 324d60765..14e4d92f0 100644
--- a/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs
+++ b/crates/hir_ty/src/diagnostics/decl_check/case_conv.rs
@@ -1,156 +1,145 @@
 //! Functions for string case manipulation, such as detecting the identifier case,
 //! and converting it into appropriate form.
 
-#[derive(Debug)]
-enum DetectedCase {
-    LowerCamelCase,
-    UpperCamelCase,
-    LowerSnakeCase,
-    UpperSnakeCase,
-    Unknown,
-}
-
-fn detect_case(ident: &str) -> DetectedCase {
-    let trimmed_ident = ident.trim_matches('_');
-    let first_lowercase = trimmed_ident.starts_with(|chr: char| chr.is_ascii_lowercase());
-    let mut has_lowercase = first_lowercase;
-    let mut has_uppercase = false;
-    let mut has_underscore = false;
-
-    for chr in trimmed_ident.chars() {
-        if chr == '_' {
-            has_underscore = true;
-        } else if chr.is_ascii_uppercase() {
-            has_uppercase = true;
-        } else if chr.is_ascii_lowercase() {
-            has_lowercase = true;
-        }
-    }
-
-    if has_uppercase {
-        if !has_lowercase {
-            if has_underscore {
-                DetectedCase::UpperSnakeCase
-            } else {
-                // It has uppercase only and no underscores. Ex: "AABB"
-                // This is a camel cased acronym.
-                DetectedCase::UpperCamelCase
-            }
-        } else if !has_underscore {
-            if first_lowercase {
-                DetectedCase::LowerCamelCase
-            } else {
-                DetectedCase::UpperCamelCase
-            }
-        } else {
-            // It has uppercase, it has lowercase, it has underscore.
-            // No assumptions here
-            DetectedCase::Unknown
-        }
-    } else {
-        DetectedCase::LowerSnakeCase
-    }
-}
+// Code that was taken from rustc was taken at commit 89fdb30,
+// from file /compiler/rustc_lint/src/nonstandard_style.rs
 
 /// Converts an identifier to an UpperCamelCase form.
 /// Returns `None` if the string is already is UpperCamelCase.
-pub fn to_camel_case(ident: &str) -> Option<String> {
-    let detected_case = detect_case(ident);
-
-    match detected_case {
-        DetectedCase::UpperCamelCase => return None,
-        DetectedCase::LowerCamelCase => {
-            let mut first_capitalized = false;
-            let output = ident
-                .chars()
-                .map(|chr| {
-                    if !first_capitalized && chr.is_ascii_lowercase() {
-                        first_capitalized = true;
-                        chr.to_ascii_uppercase()
-                    } else {
-                        chr
-                    }
-                })
-                .collect();
-            return Some(output);
-        }
-        _ => {}
+pub(crate) fn to_camel_case(ident: &str) -> Option<String> {
+    if is_camel_case(ident) {
+        return None;
     }
 
-    let mut output = String::with_capacity(ident.len());
-
-    let mut capital_added = false;
-    for chr in ident.chars() {
-        if chr.is_alphabetic() {
-            if !capital_added {
-                output.push(chr.to_ascii_uppercase());
-                capital_added = true;
-            } else {
-                output.push(chr.to_ascii_lowercase());
+    // Taken from rustc.
+    let ret = ident
+        .trim_matches('_')
+        .split('_')
+        .filter(|component| !component.is_empty())
+        .map(|component| {
+            let mut camel_cased_component = String::new();
+
+            let mut new_word = true;
+            let mut prev_is_lower_case = true;
+
+            for c in component.chars() {
+                // Preserve the case if an uppercase letter follows a lowercase letter, so that
+                // `camelCase` is converted to `CamelCase`.
+                if prev_is_lower_case && c.is_uppercase() {
+                    new_word = true;
+                }
+
+                if new_word {
+                    camel_cased_component.push_str(&c.to_uppercase().to_string());
+                } else {
+                    camel_cased_component.push_str(&c.to_lowercase().to_string());
+                }
+
+                prev_is_lower_case = c.is_lowercase();
+                new_word = false;
             }
-        } else if chr == '_' {
-            // Skip this character and make the next one capital.
-            capital_added = false;
-        } else {
-            // Put the characted as-is.
-            output.push(chr);
-        }
-    }
 
-    if output == ident {
-        // While we didn't detect the correct case at the beginning, there
-        // may be special cases: e.g. `A` is both valid CamelCase and UPPER_SNAKE_CASE.
-        None
-    } else {
-        Some(output)
-    }
+            camel_cased_component
+        })
+        .fold((String::new(), None), |(acc, prev): (String, Option<String>), next| {
+            // separate two components with an underscore if their boundary cannot
+            // be distinguished using a uppercase/lowercase case distinction
+            let join = if let Some(prev) = prev {
+                let l = prev.chars().last().unwrap();
+                let f = next.chars().next().unwrap();
+                !char_has_case(l) && !char_has_case(f)
+            } else {
+                false
+            };
+            (acc + if join { "_" } else { "" } + &next, Some(next))
+        })
+        .0;
+    Some(ret)
 }
 
 /// Converts an identifier to a lower_snake_case form.
 /// Returns `None` if the string is already in lower_snake_case.
-pub fn to_lower_snake_case(ident: &str) -> Option<String> {
-    // First, assume that it's UPPER_SNAKE_CASE.
-    match detect_case(ident) {
-        DetectedCase::LowerSnakeCase => return None,
-        DetectedCase::UpperSnakeCase => {
-            return Some(ident.chars().map(|chr| chr.to_ascii_lowercase()).collect())
-        }
-        _ => {}
+pub(crate) fn to_lower_snake_case(ident: &str) -> Option<String> {
+    if is_lower_snake_case(ident) {
+        return None;
+    } else if is_upper_snake_case(ident) {
+        return Some(ident.to_lowercase());
     }
 
-    // Otherwise, assume that it's CamelCase.
-    let lower_snake_case = stdx::to_lower_snake_case(ident);
-
-    if lower_snake_case == ident {
-        // While we didn't detect the correct case at the beginning, there
-        // may be special cases: e.g. `a` is both valid camelCase and snake_case.
-        None
-    } else {
-        Some(lower_snake_case)
-    }
+    Some(stdx::to_lower_snake_case(ident))
 }
 
 /// Converts an identifier to an UPPER_SNAKE_CASE form.
 /// Returns `None` if the string is already is UPPER_SNAKE_CASE.
-pub fn to_upper_snake_case(ident: &str) -> Option<String> {
-    match detect_case(ident) {
-        DetectedCase::UpperSnakeCase => return None,
-        DetectedCase::LowerSnakeCase => {
-            return Some(ident.chars().map(|chr| chr.to_ascii_uppercase()).collect())
-        }
-        _ => {}
+pub(crate) fn to_upper_snake_case(ident: &str) -> Option<String> {
+    if is_upper_snake_case(ident) {
+        return None;
+    } else if is_lower_snake_case(ident) {
+        return Some(ident.to_uppercase());
+    }
+
+    Some(stdx::to_upper_snake_case(ident))
+}
+
+// Taken from rustc.
+// Modified by replacing the use of unstable feature `array_windows`.
+fn is_camel_case(name: &str) -> bool {
+    let name = name.trim_matches('_');
+    if name.is_empty() {
+        return true;
     }
 
-    // Normalize the string from whatever form it's in currently, and then just make it uppercase.
-    let upper_snake_case = stdx::to_upper_snake_case(ident);
+    let mut fst = None;
+    // start with a non-lowercase letter rather than non-uppercase
+    // ones (some scripts don't have a concept of upper/lowercase)
+    !name.chars().next().unwrap().is_lowercase()
+        && !name.contains("__")
+        && !name.chars().any(|snd| {
+            let ret = match (fst, snd) {
+                (None, _) => false,
+                (Some(fst), snd) => {
+                    char_has_case(fst) && snd == '_' || char_has_case(snd) && fst == '_'
+                }
+            };
+            fst = Some(snd);
+
+            ret
+        })
+}
+
+fn is_lower_snake_case(ident: &str) -> bool {
+    is_snake_case(ident, char::is_uppercase)
+}
 
-    if upper_snake_case == ident {
-        // While we didn't detect the correct case at the beginning, there
-        // may be special cases: e.g. `A` is both valid CamelCase and UPPER_SNAKE_CASE.
-        None
-    } else {
-        Some(upper_snake_case)
+fn is_upper_snake_case(ident: &str) -> bool {
+    is_snake_case(ident, char::is_lowercase)
+}
+
+// Taken from rustc.
+// Modified to allow checking for both upper and lower snake case.
+fn is_snake_case<F: Fn(char) -> bool>(ident: &str, wrong_case: F) -> bool {
+    if ident.is_empty() {
+        return true;
     }
+    let ident = ident.trim_matches('_');
+
+    let mut allow_underscore = true;
+    ident.chars().all(|c| {
+        allow_underscore = match c {
+            '_' if !allow_underscore => return false,
+            '_' => false,
+            // It would be more obvious to check for the correct case,
+            // but some characters do not have a case.
+            c if !wrong_case(c) => true,
+            _ => return false,
+        };
+        true
+    })
+}
+
+// Taken from rustc.
+fn char_has_case(c: char) -> bool {
+    c.is_lowercase() || c.is_uppercase()
 }
 
 #[cfg(test)]
@@ -173,6 +162,7 @@ mod tests {
         check(to_lower_snake_case, "CamelCase", expect![["camel_case"]]);
         check(to_lower_snake_case, "lowerCamelCase", expect![["lower_camel_case"]]);
         check(to_lower_snake_case, "a", expect![[""]]);
+        check(to_lower_snake_case, "abc", expect![[""]]);
     }
 
     #[test]
@@ -187,6 +177,11 @@ mod tests {
         check(to_camel_case, "name", expect![["Name"]]);
         check(to_camel_case, "A", expect![[""]]);
         check(to_camel_case, "AABB", expect![[""]]);
+        // Taken from rustc: /compiler/rustc_lint/src/nonstandard_style/tests.rs
+        check(to_camel_case, "X86_64", expect![[""]]);
+        check(to_camel_case, "x86__64", expect![["X86_64"]]);
+        check(to_camel_case, "Abc_123", expect![["Abc123"]]);
+        check(to_camel_case, "A1_b2_c3", expect![["A1B2C3"]]);
     }
 
     #[test]
@@ -197,5 +192,7 @@ mod tests {
         check(to_upper_snake_case, "CamelCase", expect![["CAMEL_CASE"]]);
         check(to_upper_snake_case, "lowerCamelCase", expect![["LOWER_CAMEL_CASE"]]);
         check(to_upper_snake_case, "A", expect![[""]]);
+        check(to_upper_snake_case, "ABC", expect![[""]]);
+        check(to_upper_snake_case, "X86_64", expect![[""]]);
     }
 }
diff --git a/crates/hir_ty/src/diagnostics/expr.rs b/crates/hir_ty/src/diagnostics/expr.rs
index 278a4b947..434b19354 100644
--- a/crates/hir_ty/src/diagnostics/expr.rs
+++ b/crates/hir_ty/src/diagnostics/expr.rs
@@ -17,17 +17,10 @@ use crate::{
     ApplicationTy, InferenceResult, Ty, TypeCtor,
 };
 
-pub use hir_def::{
-    body::{
-        scope::{ExprScopes, ScopeEntry, ScopeId},
-        Body, BodySourceMap, ExprPtr, ExprSource, PatPtr, PatSource,
-    },
-    expr::{
-        ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Literal, LogicOp,
-        MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField, Statement, UnaryOp,
-    },
-    src::HasSource,
-    LocalFieldId, Lookup, VariantId,
+pub(crate) use hir_def::{
+    body::{Body, BodySourceMap},
+    expr::{Expr, ExprId, MatchArm, Pat, PatId},
+    LocalFieldId, VariantId,
 };
 
 pub(super) struct ExprValidator<'a, 'b: 'a> {
diff --git a/crates/hir_ty/src/diagnostics/unsafe_check.rs b/crates/hir_ty/src/diagnostics/unsafe_check.rs
index 2da9688ca..6dc862826 100644
--- a/crates/hir_ty/src/diagnostics/unsafe_check.rs
+++ b/crates/hir_ty/src/diagnostics/unsafe_check.rs
@@ -59,12 +59,12 @@ impl<'a, 'b> UnsafeValidator<'a, 'b> {
     }
 }
 
-pub struct UnsafeExpr {
-    pub expr: ExprId,
-    pub inside_unsafe_block: bool,
+pub(crate) struct UnsafeExpr {
+    pub(crate) expr: ExprId,
+    pub(crate) inside_unsafe_block: bool,
 }
 
-pub fn unsafe_expressions(
+pub(crate) fn unsafe_expressions(
     db: &dyn HirDatabase,
     infer: &InferenceResult,
     def: DefWithBodyId,
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index d2e151f25..14e8c0633 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -26,6 +26,20 @@ pub trait HirDisplay {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError>;
 
     /// Returns a `Display`able type that is human-readable.
+    fn into_displayable<'a>(
+        &'a self,
+        db: &'a dyn HirDatabase,
+        max_size: Option<usize>,
+        omit_verbose_types: bool,
+        display_target: DisplayTarget,
+    ) -> HirDisplayWrapper<'a, Self>
+    where
+        Self: Sized,
+    {
+        HirDisplayWrapper { db, t: self, max_size, omit_verbose_types, display_target }
+    }
+
+    /// Returns a `Display`able type that is human-readable.
     /// Use this for showing types to the user (e.g. diagnostics)
     fn display<'a>(&'a self, db: &'a dyn HirDatabase) -> HirDisplayWrapper<'a, Self>
     where
@@ -82,6 +96,20 @@ pub trait HirDisplay {
         };
         Ok(result)
     }
+
+    /// Returns a String representation of `self` for test purposes
+    fn display_test<'a>(&'a self, db: &'a dyn HirDatabase) -> HirDisplayWrapper<'a, Self>
+    where
+        Self: Sized,
+    {
+        HirDisplayWrapper {
+            db,
+            t: self,
+            max_size: None,
+            omit_verbose_types: false,
+            display_target: DisplayTarget::Test,
+        }
+    }
 }
 
 impl<'a> HirFormatter<'a> {
@@ -126,7 +154,7 @@ impl<'a> HirFormatter<'a> {
 }
 
 #[derive(Clone, Copy)]
-enum DisplayTarget {
+pub enum DisplayTarget {
     /// Display types for inlays, doc popups, autocompletion, etc...
     /// Showing `{unknown}` or not qualifying paths is fine here.
     /// There's no reason for this to fail.
@@ -134,12 +162,17 @@ enum DisplayTarget {
     /// Display types for inserting them in source files.
     /// The generated code should compile, so paths need to be qualified.
     SourceCode { module_id: ModuleId },
+    /// Only for test purpose to keep real types
+    Test,
 }
 
 impl DisplayTarget {
     fn is_source_code(&self) -> bool {
         matches!(self, Self::SourceCode {..})
     }
+    fn is_test(&self) -> bool {
+        matches!(self, Self::Test)
+    }
 }
 
 #[derive(Debug)]
@@ -213,32 +246,32 @@ impl HirDisplay for ApplicationTy {
             TypeCtor::Str => write!(f, "str")?,
             TypeCtor::Slice => {
                 let t = self.parameters.as_single();
-                write!(f, "[{}]", t.display(f.db))?;
+                write!(f, "[")?;
+                t.hir_fmt(f)?;
+                write!(f, "]")?;
             }
             TypeCtor::Array => {
                 let t = self.parameters.as_single();
-                write!(f, "[{}; _]", t.display(f.db))?;
+                write!(f, "[")?;
+                t.hir_fmt(f)?;
+                write!(f, "; _]")?;
             }
             TypeCtor::RawPtr(m) => {
                 let t = self.parameters.as_single();
-                let ty_display = t.display(f.db);
 
                 write!(f, "*{}", m.as_keyword_for_ptr())?;
                 if matches!(t, Ty::Dyn(predicates) if predicates.len() > 1) {
                     write!(f, "(")?;
-                    write!(f, "{}", ty_display)?;
+                    t.hir_fmt(f)?;
                     write!(f, ")")?;
                 } else {
-                    write!(f, "{}", ty_display)?;
+                    t.hir_fmt(f)?;
                 }
             }
             TypeCtor::Ref(m) => {
                 let t = self.parameters.as_single();
-                let ty_display = if f.omit_verbose_types() {
-                    t.display_truncated(f.db, f.max_size)
-                } else {
-                    t.display(f.db)
-                };
+                let ty_display =
+                    t.into_displayable(f.db, f.max_size, f.omit_verbose_types, f.display_target);
 
                 write!(f, "&{}", m.as_keyword_for_ref())?;
                 if matches!(t, Ty::Dyn(predicates) if predicates.len() > 1) {
@@ -253,7 +286,9 @@ impl HirDisplay for ApplicationTy {
             TypeCtor::Tuple { .. } => {
                 let ts = &self.parameters;
                 if ts.len() == 1 {
-                    write!(f, "({},)", ts[0].display(f.db))?;
+                    write!(f, "(")?;
+                    ts[0].hir_fmt(f)?;
+                    write!(f, ",)")?;
                 } else {
                     write!(f, "(")?;
                     f.write_joined(&*ts.0, ", ")?;
@@ -274,11 +309,12 @@ impl HirDisplay for ApplicationTy {
                 write!(f, ")")?;
                 let ret = sig.ret();
                 if *ret != Ty::unit() {
-                    let ret_display = if f.omit_verbose_types() {
-                        ret.display_truncated(f.db, f.max_size)
-                    } else {
-                        ret.display(f.db)
-                    };
+                    let ret_display = ret.into_displayable(
+                        f.db,
+                        f.max_size,
+                        f.omit_verbose_types,
+                        f.display_target,
+                    );
                     write!(f, " -> {}", ret_display)?;
                 }
             }
@@ -310,17 +346,19 @@ impl HirDisplay for ApplicationTy {
                 write!(f, ")")?;
                 let ret = sig.ret();
                 if *ret != Ty::unit() {
-                    let ret_display = if f.omit_verbose_types() {
-                        ret.display_truncated(f.db, f.max_size)
-                    } else {
-                        ret.display(f.db)
-                    };
+                    let ret_display = ret.into_displayable(
+                        f.db,
+                        f.max_size,
+                        f.omit_verbose_types,
+                        f.display_target,
+                    );
+
                     write!(f, " -> {}", ret_display)?;
                 }
             }
             TypeCtor::Adt(def_id) => {
                 match f.display_target {
-                    DisplayTarget::Diagnostics => {
+                    DisplayTarget::Diagnostics | DisplayTarget::Test => {
                         let name = match def_id {
                             AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
                             AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
@@ -389,12 +427,23 @@ impl HirDisplay for ApplicationTy {
                     _ => panic!("not an associated type"),
                 };
                 let trait_ = f.db.trait_data(trait_);
-                let type_alias = f.db.type_alias_data(type_alias);
-                write!(f, "{}::{}", trait_.name, type_alias.name)?;
-                if self.parameters.len() > 0 {
-                    write!(f, "<")?;
-                    f.write_joined(&*self.parameters.0, ", ")?;
-                    write!(f, ">")?;
+                let type_alias_data = f.db.type_alias_data(type_alias);
+
+                // Use placeholder associated types when the target is test (https://rust-lang.github.io/chalk/book/clauses/type_equality.html#placeholder-associated-types)
+                if f.display_target.is_test() {
+                    write!(f, "{}::{}", trait_.name, type_alias_data.name)?;
+                    if self.parameters.len() > 0 {
+                        write!(f, "<")?;
+                        f.write_joined(&*self.parameters.0, ", ")?;
+                        write!(f, ">")?;
+                    }
+                } else {
+                    let projection_ty = ProjectionTy {
+                        associated_ty: type_alias,
+                        parameters: self.parameters.clone(),
+                    };
+
+                    projection_ty.hir_fmt(f)?;
                 }
             }
             TypeCtor::ForeignType(type_alias) => {
@@ -439,11 +488,12 @@ impl HirDisplay for ApplicationTy {
                         write!(f, "|")?;
                     };
 
-                    let ret_display = if f.omit_verbose_types() {
-                        sig.ret().display_truncated(f.db, f.max_size)
-                    } else {
-                        sig.ret().display(f.db)
-                    };
+                    let ret_display = sig.ret().into_displayable(
+                        f.db,
+                        f.max_size,
+                        f.omit_verbose_types,
+                        f.display_target,
+                    );
                     write!(f, " -> {}", ret_display)?;
                 } else {
                     write!(f, "{{closure}}")?;
@@ -461,7 +511,13 @@ impl HirDisplay for ProjectionTy {
         }
 
         let trait_ = f.db.trait_data(self.trait_(f.db));
-        write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_.name)?;
+        let first_parameter = self.parameters[0].into_displayable(
+            f.db,
+            f.max_size,
+            f.omit_verbose_types,
+            f.display_target,
+        );
+        write!(f, "<{} as {}", first_parameter, trait_.name)?;
         if self.parameters.len() > 1 {
             write!(f, "<")?;
             f.write_joined(&self.parameters[1..], ", ")?;
@@ -640,10 +696,10 @@ impl HirDisplay for GenericPredicate {
                 projection_pred.projection_ty.trait_ref(f.db).hir_fmt_ext(f, true)?;
                 write!(
                     f,
-                    ">::{} = {}",
+                    ">::{} = ",
                     f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name,
-                    projection_pred.ty.display(f.db)
                 )?;
+                projection_pred.ty.hir_fmt(f)?;
             }
             GenericPredicate::Error => write!(f, "{{error}}")?,
         }
@@ -654,13 +710,18 @@ impl HirDisplay for GenericPredicate {
 impl HirDisplay for Obligation {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         match self {
-            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
-            Obligation::Projection(proj) => write!(
-                f,
-                "Normalize({} => {})",
-                proj.projection_ty.display(f.db),
-                proj.ty.display(f.db)
-            ),
+            Obligation::Trait(tr) => {
+                write!(f, "Implements(")?;
+                tr.hir_fmt(f)?;
+                write!(f, ")")
+            }
+            Obligation::Projection(proj) => {
+                write!(f, "Normalize(")?;
+                proj.projection_ty.hir_fmt(f)?;
+                write!(f, " => ")?;
+                proj.ty.hir_fmt(f)?;
+                write!(f, ")")
+            }
         }
     }
 }
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index 644ebd42d..a14d67c06 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -94,7 +94,7 @@ enum BindingMode {
 }
 
 impl BindingMode {
-    pub fn convert(annotation: BindingAnnotation) -> BindingMode {
+    fn convert(annotation: BindingAnnotation) -> BindingMode {
         match annotation {
             BindingAnnotation::Unannotated | BindingAnnotation::Mutable => BindingMode::Move,
             BindingAnnotation::Ref => BindingMode::Ref(Mutability::Shared),
@@ -214,9 +214,9 @@ struct InferenceContext<'a> {
 
 #[derive(Clone, Debug)]
 struct BreakableContext {
-    pub may_break: bool,
-    pub break_ty: Ty,
-    pub label: Option<name::Name>,
+    may_break: bool,
+    break_ty: Ty,
+    label: Option<name::Name>,
 }
 
 fn find_breakable<'c>(
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 8ac4cf89a..605951b10 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -107,7 +107,7 @@ impl<'a> InferenceContext<'a> {
         }
     }
 
-    pub fn callable_sig(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec<Ty>, Ty)> {
+    pub(crate) fn callable_sig(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec<Ty>, Ty)> {
         match ty.callable_sig(self.db) {
             Some(sig) => Some((sig.params().to_vec(), sig.ret().clone())),
             None => self.callable_sig_from_fn_trait(ty, num_args),
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index 2e895d911..76984242e 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -35,7 +35,7 @@ where
 
 #[derive(Debug)]
 pub(super) struct Canonicalized<T> {
-    pub value: Canonical<T>,
+    pub(super) value: Canonical<T>,
     free_vars: Vec<InferTy>,
 }
 
@@ -127,7 +127,7 @@ where
 }
 
 impl<T> Canonicalized<T> {
-    pub fn decanonicalize_ty(&self, mut ty: Ty) -> Ty {
+    pub(super) fn decanonicalize_ty(&self, mut ty: Ty) -> Ty {
         ty.walk_mut_binders(
             &mut |ty, binders| {
                 if let &mut Ty::Bound(bound) = ty {
@@ -141,7 +141,11 @@ impl<T> Canonicalized<T> {
         ty
     }
 
-    pub fn apply_solution(&self, ctx: &mut InferenceContext<'_>, solution: Canonical<Substs>) {
+    pub(super) fn apply_solution(
+        &self,
+        ctx: &mut InferenceContext<'_>,
+        solution: Canonical<Substs>,
+    ) {
         // the solution may contain new variables, which we need to convert to new inference vars
         let new_vars = Substs(
             solution
@@ -164,7 +168,7 @@ impl<T> Canonicalized<T> {
     }
 }
 
-pub fn unify(tys: &Canonical<(Ty, Ty)>) -> Option<Substs> {
+pub(crate) fn unify(tys: &Canonical<(Ty, Ty)>) -> Option<Substs> {
     let mut table = InferenceTable::new();
     let vars = Substs(
         tys.kinds
@@ -199,41 +203,46 @@ pub(crate) struct InferenceTable {
 }
 
 impl InferenceTable {
-    pub fn new() -> Self {
+    pub(crate) fn new() -> Self {
         InferenceTable { var_unification_table: InPlaceUnificationTable::new() }
     }
 
-    pub fn new_type_var(&mut self) -> Ty {
+    pub(crate) fn new_type_var(&mut self) -> Ty {
         Ty::Infer(InferTy::TypeVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
     }
 
-    pub fn new_integer_var(&mut self) -> Ty {
+    pub(crate) fn new_integer_var(&mut self) -> Ty {
         Ty::Infer(InferTy::IntVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
     }
 
-    pub fn new_float_var(&mut self) -> Ty {
+    pub(crate) fn new_float_var(&mut self) -> Ty {
         Ty::Infer(InferTy::FloatVar(self.var_unification_table.new_key(TypeVarValue::Unknown)))
     }
 
-    pub fn new_maybe_never_type_var(&mut self) -> Ty {
+    pub(crate) fn new_maybe_never_type_var(&mut self) -> Ty {
         Ty::Infer(InferTy::MaybeNeverTypeVar(
             self.var_unification_table.new_key(TypeVarValue::Unknown),
         ))
     }
 
-    pub fn resolve_ty_completely(&mut self, ty: Ty) -> Ty {
+    pub(crate) fn resolve_ty_completely(&mut self, ty: Ty) -> Ty {
         self.resolve_ty_completely_inner(&mut Vec::new(), ty)
     }
 
-    pub fn resolve_ty_as_possible(&mut self, ty: Ty) -> Ty {
+    pub(crate) fn resolve_ty_as_possible(&mut self, ty: Ty) -> Ty {
         self.resolve_ty_as_possible_inner(&mut Vec::new(), ty)
     }
 
-    pub fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
+    pub(crate) fn unify(&mut self, ty1: &Ty, ty2: &Ty) -> bool {
         self.unify_inner(ty1, ty2, 0)
     }
 
-    pub fn unify_substs(&mut self, substs1: &Substs, substs2: &Substs, depth: usize) -> bool {
+    pub(crate) fn unify_substs(
+        &mut self,
+        substs1: &Substs,
+        substs2: &Substs,
+        depth: usize,
+    ) -> bool {
         substs1.0.iter().zip(substs2.0.iter()).all(|(t1, t2)| self.unify_inner(t1, t2, depth))
     }
 
@@ -331,7 +340,7 @@ impl InferenceTable {
 
     /// If `ty` is a type variable with known type, returns that type;
     /// otherwise, return ty.
-    pub fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
+    pub(crate) fn resolve_ty_shallow<'b>(&mut self, ty: &'b Ty) -> Cow<'b, Ty> {
         let mut ty = Cow::Borrowed(ty);
         // The type variable could resolve to a int/float variable. Hence try
         // resolving up to three times; each type of variable shouldn't occur
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 768d95eff..5a8c97198 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -1,6 +1,5 @@
 //! The type system. We currently use this to infer types for completion, hover
 //! information and various assists.
-
 #[allow(unused)]
 macro_rules! eprintln {
     ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
@@ -1115,5 +1114,5 @@ pub struct ReturnTypeImplTraits {
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub(crate) struct ReturnTypeImplTrait {
-    pub bounds: Binders<Vec<GenericPredicate>>,
+    pub(crate) bounds: Binders<Vec<GenericPredicate>>,
 }
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 8961df404..5a6f0c67f 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -740,6 +740,19 @@ pub fn implements_trait(
     solution.is_some()
 }
 
+pub fn implements_trait_unique(
+    ty: &Canonical<Ty>,
+    db: &dyn HirDatabase,
+    env: Arc<TraitEnvironment>,
+    krate: CrateId,
+    trait_: TraitId,
+) -> bool {
+    let goal = generic_implements_goal(db, env, trait_, ty.clone());
+    let solution = db.trait_solve(krate, goal);
+
+    matches!(solution, Some(crate::traits::Solution::Unique(_)))
+}
+
 /// This creates Substs for a trait with the given Self type and type variables
 /// for all other parameters, to query Chalk with it.
 fn generic_implements_goal(
diff --git a/crates/hir_ty/src/test_db.rs b/crates/hir_ty/src/test_db.rs
index 15b8435e9..22254b765 100644
--- a/crates/hir_ty/src/test_db.rs
+++ b/crates/hir_ty/src/test_db.rs
@@ -21,7 +21,7 @@ use test_utils::extract_annotations;
     crate::db::HirDatabaseStorage
 )]
 #[derive(Default)]
-pub struct TestDB {
+pub(crate) struct TestDB {
     storage: salsa::Storage<TestDB>,
     events: Mutex<Option<Vec<salsa::Event>>>,
 }
@@ -113,13 +113,13 @@ impl TestDB {
 }
 
 impl TestDB {
-    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
+    pub(crate) fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
         *self.events.lock().unwrap() = Some(Vec::new());
         f();
         self.events.lock().unwrap().take().unwrap()
     }
 
-    pub fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
+    pub(crate) fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
         let events = self.log(f);
         events
             .into_iter()
diff --git a/crates/hir_ty/src/tests.rs b/crates/hir_ty/src/tests.rs
index 0445efc9e..104ef334c 100644
--- a/crates/hir_ty/src/tests.rs
+++ b/crates/hir_ty/src/tests.rs
@@ -74,7 +74,7 @@ fn check_types_impl(ra_fixture: &str, display_source: bool) {
                 let module = db.module_for_file(file_id);
                 ty.display_source_code(&db, module).unwrap()
             } else {
-                ty.display(&db).to_string()
+                ty.display_test(&db).to_string()
             };
             assert_eq!(expected, actual);
             checked_one = true;
@@ -163,7 +163,7 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
                 macro_prefix,
                 range,
                 ellipsize(text, 15),
-                ty.display(&db)
+                ty.display_test(&db)
             );
         }
         if include_mismatches {
@@ -179,8 +179,8 @@ fn infer_with_mismatches(content: &str, include_mismatches: bool) -> String {
                     "{}{:?}: expected {}, got {}\n",
                     macro_prefix,
                     range,
-                    mismatch.expected.display(&db),
-                    mismatch.actual.display(&db),
+                    mismatch.expected.display_test(&db),
+                    mismatch.actual.display_test(&db),
                 );
             }
         }
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index cbe5cd7dd..55e2c3a3e 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 
 use log::debug;
 
-use chalk_ir::{fold::shift::Shift, CanonicalVarKinds, GenericArg, TypeName};
+use chalk_ir::{fold::shift::Shift, CanonicalVarKinds, GenericArg};
 use chalk_solve::rust_ir::{self, OpaqueTyDatumBound, WellKnownTrait};
 
 use base_db::{salsa::InternKey, CrateId};
@@ -27,7 +27,7 @@ use mapping::{
     TypeAliasAsValue,
 };
 
-pub use self::interner::*;
+pub(crate) use self::interner::*;
 
 pub(super) mod tls;
 mod interner;
@@ -81,7 +81,10 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
         let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref(&Interner).clone());
 
-        fn binder_kind(ty: &Ty, binders: &CanonicalVarKinds<Interner>) -> Option<chalk_ir::TyKind> {
+        fn binder_kind(
+            ty: &Ty,
+            binders: &CanonicalVarKinds<Interner>,
+        ) -> Option<chalk_ir::TyVariableKind> {
             if let Ty::Bound(bv) = ty {
                 let binders = binders.as_slice(&Interner);
                 if bv.debruijn == DebruijnIndex::INNERMOST {
@@ -95,8 +98,8 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
         let self_ty_fp = TyFingerprint::for_impl(&ty);
         let fps: &[TyFingerprint] = match binder_kind(&ty, binders) {
-            Some(chalk_ir::TyKind::Integer) => &ALL_INT_FPS,
-            Some(chalk_ir::TyKind::Float) => &ALL_FLOAT_FPS,
+            Some(chalk_ir::TyVariableKind::Integer) => &ALL_INT_FPS,
+            Some(chalk_ir::TyVariableKind::Float) => &ALL_FLOAT_FPS,
             _ => self_ty_fp.as_ref().map(std::slice::from_ref).unwrap_or(&[]),
         };
 
@@ -129,12 +132,8 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         debug!("impls_for_trait returned {} impls", result.len());
         result
     }
-    fn impl_provided_for(
-        &self,
-        auto_trait_id: TraitId,
-        application_ty: &chalk_ir::ApplicationTy<Interner>,
-    ) -> bool {
-        debug!("impl_provided_for {:?}, {:?}", auto_trait_id, application_ty);
+    fn impl_provided_for(&self, auto_trait_id: TraitId, kind: &chalk_ir::TyKind<Interner>) -> bool {
+        debug!("impl_provided_for {:?}, {:?}", auto_trait_id, kind);
         false // FIXME
     }
     fn associated_ty_value(&self, id: AssociatedTyValueId) -> Arc<AssociatedTyValue> {
@@ -466,7 +465,7 @@ pub(crate) fn struct_datum_query(
     struct_id: AdtId,
 ) -> Arc<StructDatum> {
     debug!("struct_datum {:?}", struct_id);
-    let type_ctor: TypeCtor = from_chalk(db, TypeName::Adt(struct_id));
+    let type_ctor = TypeCtor::Adt(from_chalk(db, struct_id));
     debug!("struct {:?} = {:?}", struct_id, type_ctor);
     let num_params = type_ctor.num_ty_params(db);
     let upstream = type_ctor.krate(db) != Some(krate);
diff --git a/crates/hir_ty/src/traits/chalk/interner.rs b/crates/hir_ty/src/traits/chalk/interner.rs
index f9304b7d0..39569e690 100644
--- a/crates/hir_ty/src/traits/chalk/interner.rs
+++ b/crates/hir_ty/src/traits/chalk/interner.rs
@@ -10,21 +10,21 @@ use std::{fmt, sync::Arc};
 #[derive(Debug, Copy, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
 pub struct Interner;
 
-pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
-pub type AssociatedTyDatum = chalk_solve::rust_ir::AssociatedTyDatum<Interner>;
-pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
-pub type TraitId = chalk_ir::TraitId<Interner>;
-pub type TraitDatum = chalk_solve::rust_ir::TraitDatum<Interner>;
-pub type AdtId = chalk_ir::AdtId<Interner>;
-pub type StructDatum = chalk_solve::rust_ir::AdtDatum<Interner>;
-pub type ImplId = chalk_ir::ImplId<Interner>;
-pub type ImplDatum = chalk_solve::rust_ir::ImplDatum<Interner>;
-pub type AssociatedTyValueId = chalk_solve::rust_ir::AssociatedTyValueId<Interner>;
-pub type AssociatedTyValue = chalk_solve::rust_ir::AssociatedTyValue<Interner>;
-pub type FnDefId = chalk_ir::FnDefId<Interner>;
-pub type FnDefDatum = chalk_solve::rust_ir::FnDefDatum<Interner>;
-pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
-pub type OpaqueTyDatum = chalk_solve::rust_ir::OpaqueTyDatum<Interner>;
+pub(crate) type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
+pub(crate) type AssociatedTyDatum = chalk_solve::rust_ir::AssociatedTyDatum<Interner>;
+pub(crate) type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
+pub(crate) type TraitId = chalk_ir::TraitId<Interner>;
+pub(crate) type TraitDatum = chalk_solve::rust_ir::TraitDatum<Interner>;
+pub(crate) type AdtId = chalk_ir::AdtId<Interner>;
+pub(crate) type StructDatum = chalk_solve::rust_ir::AdtDatum<Interner>;
+pub(crate) type ImplId = chalk_ir::ImplId<Interner>;
+pub(crate) type ImplDatum = chalk_solve::rust_ir::ImplDatum<Interner>;
+pub(crate) type AssociatedTyValueId = chalk_solve::rust_ir::AssociatedTyValueId<Interner>;
+pub(crate) type AssociatedTyValue = chalk_solve::rust_ir::AssociatedTyValue<Interner>;
+pub(crate) type FnDefId = chalk_ir::FnDefId<Interner>;
+pub(crate) type FnDefDatum = chalk_solve::rust_ir::FnDefDatum<Interner>;
+pub(crate) type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
+pub(crate) type OpaqueTyDatum = chalk_solve::rust_ir::OpaqueTyDatum<Interner>;
 
 impl chalk_ir::interner::Interner for Interner {
     type InternedType = Arc<chalk_ir::TyData<Self>>;
@@ -122,13 +122,6 @@ impl chalk_ir::interner::Interner for Interner {
         tls::with_current_program(|prog| Some(prog?.debug_program_clause_implication(pci, fmt)))
     }
 
-    fn debug_application_ty(
-        application_ty: &chalk_ir::ApplicationTy<Interner>,
-        fmt: &mut fmt::Formatter<'_>,
-    ) -> Option<fmt::Result> {
-        tls::with_current_program(|prog| Some(prog?.debug_application_ty(application_ty, fmt)))
-    }
-
     fn debug_substitution(
         substitution: &chalk_ir::Substitution<Interner>,
         fmt: &mut fmt::Formatter<'_>,
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index be3301313..86cbc4c7e 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -4,7 +4,7 @@
 //! conversions.
 
 use chalk_ir::{
-    cast::Cast, fold::shift::Shift, interner::HasInterner, PlaceholderIndex, Scalar, TypeName,
+    cast::Cast, fold::shift::Shift, interner::HasInterner, LifetimeData, PlaceholderIndex, Scalar,
     UniverseIndex,
 };
 use chalk_solve::rust_ir;
@@ -32,7 +32,7 @@ impl ToChalk for Ty {
                 TypeCtor::Array => array_to_chalk(db, apply_ty.parameters),
                 TypeCtor::FnPtr { num_args: _, is_varargs } => {
                     let substitution = apply_ty.parameters.to_chalk(db).shifted_in(&Interner);
-                    chalk_ir::TyData::Function(chalk_ir::FnPointer {
+                    chalk_ir::TyKind::Function(chalk_ir::FnPointer {
                         num_binders: 0,
                         sig: chalk_ir::FnSig {
                             abi: (),
@@ -43,10 +43,68 @@ impl ToChalk for Ty {
                     })
                     .intern(&Interner)
                 }
-                _ => {
-                    let name = apply_ty.ctor.to_chalk(db);
+                TypeCtor::AssociatedType(type_alias) => {
+                    let assoc_type = TypeAliasAsAssocType(type_alias);
+                    let assoc_type_id = assoc_type.to_chalk(db);
                     let substitution = apply_ty.parameters.to_chalk(db);
-                    chalk_ir::ApplicationTy { name, substitution }.cast(&Interner).intern(&Interner)
+                    chalk_ir::TyKind::AssociatedType(assoc_type_id, substitution).intern(&Interner)
+                }
+
+                TypeCtor::OpaqueType(impl_trait_id) => {
+                    let id = impl_trait_id.to_chalk(db);
+                    let substitution = apply_ty.parameters.to_chalk(db);
+                    chalk_ir::TyKind::OpaqueType(id, substitution).intern(&Interner)
+                }
+
+                TypeCtor::ForeignType(type_alias) => {
+                    let foreign_type = TypeAliasAsForeignType(type_alias);
+                    let foreign_type_id = foreign_type.to_chalk(db);
+                    chalk_ir::TyKind::Foreign(foreign_type_id).intern(&Interner)
+                }
+
+                TypeCtor::Bool => chalk_ir::TyKind::Scalar(Scalar::Bool).intern(&Interner),
+                TypeCtor::Char => chalk_ir::TyKind::Scalar(Scalar::Char).intern(&Interner),
+                TypeCtor::Int(int_ty) => {
+                    chalk_ir::TyKind::Scalar(int_ty_to_chalk(int_ty)).intern(&Interner)
+                }
+                TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 }) => {
+                    chalk_ir::TyKind::Scalar(Scalar::Float(chalk_ir::FloatTy::F32))
+                        .intern(&Interner)
+                }
+                TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 }) => {
+                    chalk_ir::TyKind::Scalar(Scalar::Float(chalk_ir::FloatTy::F64))
+                        .intern(&Interner)
+                }
+
+                TypeCtor::Tuple { cardinality } => {
+                    let substitution = apply_ty.parameters.to_chalk(db);
+                    chalk_ir::TyKind::Tuple(cardinality.into(), substitution).intern(&Interner)
+                }
+                TypeCtor::RawPtr(mutability) => {
+                    let ty = apply_ty.parameters[0].clone().to_chalk(db);
+                    chalk_ir::TyKind::Raw(mutability.to_chalk(db), ty).intern(&Interner)
+                }
+                TypeCtor::Slice => {
+                    chalk_ir::TyKind::Slice(apply_ty.parameters[0].clone().to_chalk(db))
+                        .intern(&Interner)
+                }
+                TypeCtor::Str => chalk_ir::TyKind::Str.intern(&Interner),
+                TypeCtor::FnDef(callable_def) => {
+                    let id = callable_def.to_chalk(db);
+                    let substitution = apply_ty.parameters.to_chalk(db);
+                    chalk_ir::TyKind::FnDef(id, substitution).intern(&Interner)
+                }
+                TypeCtor::Never => chalk_ir::TyKind::Never.intern(&Interner),
+
+                TypeCtor::Closure { def, expr } => {
+                    let closure_id = db.intern_closure((def, expr));
+                    let substitution = apply_ty.parameters.to_chalk(db);
+                    chalk_ir::TyKind::Closure(closure_id.into(), substitution).intern(&Interner)
+                }
+
+                TypeCtor::Adt(adt_id) => {
+                    let substitution = apply_ty.parameters.to_chalk(db);
+                    chalk_ir::TyKind::Adt(chalk_ir::AdtId(adt_id), substitution).intern(&Interner)
                 }
             },
             Ty::Projection(proj_ty) => {
@@ -67,7 +125,7 @@ impl ToChalk for Ty {
                 }
                 .to_ty::<Interner>(&Interner)
             }
-            Ty::Bound(idx) => chalk_ir::TyData::BoundVar(idx).intern(&Interner),
+            Ty::Bound(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
             Ty::Infer(_infer_ty) => panic!("uncanonicalized infer ty"),
             Ty::Dyn(predicates) => {
                 let where_clauses = chalk_ir::QuantifiedWhereClauses::from_iter(
@@ -76,57 +134,47 @@ impl ToChalk for Ty {
                 );
                 let bounded_ty = chalk_ir::DynTy {
                     bounds: make_binders(where_clauses, 1),
-                    lifetime: FAKE_PLACEHOLDER.to_lifetime(&Interner),
+                    lifetime: LifetimeData::Static.intern(&Interner),
                 };
-                chalk_ir::TyData::Dyn(bounded_ty).intern(&Interner)
+                chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
             }
             Ty::Opaque(opaque_ty) => {
                 let opaque_ty_id = opaque_ty.opaque_ty_id.to_chalk(db);
                 let substitution = opaque_ty.parameters.to_chalk(db);
-                chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
+                chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
                     opaque_ty_id,
                     substitution,
                 }))
                 .intern(&Interner)
             }
-            Ty::Unknown => {
-                let substitution = chalk_ir::Substitution::empty(&Interner);
-                let name = TypeName::Error;
-                chalk_ir::ApplicationTy { name, substitution }.cast(&Interner).intern(&Interner)
-            }
+            Ty::Unknown => chalk_ir::TyKind::Error.intern(&Interner),
         }
     }
     fn from_chalk(db: &dyn HirDatabase, chalk: chalk_ir::Ty<Interner>) -> Self {
-        match chalk.data(&Interner).clone() {
-            chalk_ir::TyData::Apply(apply_ty) => match apply_ty.name {
-                TypeName::Error => Ty::Unknown,
-                TypeName::Ref(m) => ref_from_chalk(db, m, apply_ty.substitution),
-                TypeName::Array => array_from_chalk(db, apply_ty.substitution),
-                _ => {
-                    let ctor = from_chalk(db, apply_ty.name);
-                    let parameters = from_chalk(db, apply_ty.substitution);
-                    Ty::Apply(ApplicationTy { ctor, parameters })
-                }
-            },
-            chalk_ir::TyData::Placeholder(idx) => {
+        match chalk.data(&Interner).kind.clone() {
+            chalk_ir::TyKind::Error => Ty::Unknown,
+            chalk_ir::TyKind::Array(ty, _size) => {
+                Ty::apply(TypeCtor::Array, Substs::single(from_chalk(db, ty)))
+            }
+            chalk_ir::TyKind::Placeholder(idx) => {
                 assert_eq!(idx.ui, UniverseIndex::ROOT);
                 let interned_id = crate::db::GlobalTypeParamId::from_intern_id(
                     crate::salsa::InternId::from(idx.idx),
                 );
                 Ty::Placeholder(db.lookup_intern_type_param_id(interned_id))
             }
-            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Projection(proj)) => {
+            chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Projection(proj)) => {
                 let associated_ty =
                     from_chalk::<TypeAliasAsAssocType, _>(db, proj.associated_ty_id).0;
                 let parameters = from_chalk(db, proj.substitution);
                 Ty::Projection(ProjectionTy { associated_ty, parameters })
             }
-            chalk_ir::TyData::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
+            chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
                 let impl_trait_id = from_chalk(db, opaque_ty.opaque_ty_id);
                 let parameters = from_chalk(db, opaque_ty.substitution);
                 Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
             }
-            chalk_ir::TyData::Function(chalk_ir::FnPointer {
+            chalk_ir::TyKind::Function(chalk_ir::FnPointer {
                 num_binders,
                 sig: chalk_ir::FnSig { variadic, .. },
                 substitution,
@@ -145,9 +193,9 @@ impl ToChalk for Ty {
                     parameters,
                 })
             }
-            chalk_ir::TyData::BoundVar(idx) => Ty::Bound(idx),
-            chalk_ir::TyData::InferenceVar(_iv, _kind) => Ty::Unknown,
-            chalk_ir::TyData::Dyn(where_clauses) => {
+            chalk_ir::TyKind::BoundVar(idx) => Ty::Bound(idx),
+            chalk_ir::TyKind::InferenceVar(_iv, _kind) => Ty::Unknown,
+            chalk_ir::TyKind::Dyn(where_clauses) => {
                 assert_eq!(where_clauses.bounds.binders.len(&Interner), 1);
                 let predicates = where_clauses
                     .bounds
@@ -157,12 +205,75 @@ impl ToChalk for Ty {
                     .collect();
                 Ty::Dyn(predicates)
             }
+
+            chalk_ir::TyKind::Adt(struct_id, subst) => {
+                apply_ty_from_chalk(db, TypeCtor::Adt(struct_id.0), subst)
+            }
+            chalk_ir::TyKind::AssociatedType(type_id, subst) => apply_ty_from_chalk(
+                db,
+                TypeCtor::AssociatedType(from_chalk::<TypeAliasAsAssocType, _>(db, type_id).0),
+                subst,
+            ),
+            chalk_ir::TyKind::OpaqueType(opaque_type_id, subst) => {
+                apply_ty_from_chalk(db, TypeCtor::OpaqueType(from_chalk(db, opaque_type_id)), subst)
+            }
+
+            chalk_ir::TyKind::Scalar(Scalar::Bool) => Ty::simple(TypeCtor::Bool),
+            chalk_ir::TyKind::Scalar(Scalar::Char) => Ty::simple(TypeCtor::Char),
+            chalk_ir::TyKind::Scalar(Scalar::Int(int_ty)) => Ty::simple(TypeCtor::Int(IntTy {
+                signedness: Signedness::Signed,
+                bitness: bitness_from_chalk_int(int_ty),
+            })),
+            chalk_ir::TyKind::Scalar(Scalar::Uint(uint_ty)) => Ty::simple(TypeCtor::Int(IntTy {
+                signedness: Signedness::Unsigned,
+                bitness: bitness_from_chalk_uint(uint_ty),
+            })),
+            chalk_ir::TyKind::Scalar(Scalar::Float(chalk_ir::FloatTy::F32)) => {
+                Ty::simple(TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 }))
+            }
+            chalk_ir::TyKind::Scalar(Scalar::Float(chalk_ir::FloatTy::F64)) => {
+                Ty::simple(TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 }))
+            }
+            chalk_ir::TyKind::Tuple(cardinality, subst) => {
+                apply_ty_from_chalk(db, TypeCtor::Tuple { cardinality: cardinality as u16 }, subst)
+            }
+            chalk_ir::TyKind::Raw(mutability, ty) => {
+                Ty::apply_one(TypeCtor::RawPtr(from_chalk(db, mutability)), from_chalk(db, ty))
+            }
+            chalk_ir::TyKind::Slice(ty) => Ty::apply_one(TypeCtor::Slice, from_chalk(db, ty)),
+            chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {
+                Ty::apply_one(TypeCtor::Ref(from_chalk(db, mutability)), from_chalk(db, ty))
+            }
+            chalk_ir::TyKind::Str => Ty::simple(TypeCtor::Str),
+            chalk_ir::TyKind::Never => Ty::simple(TypeCtor::Never),
+
+            chalk_ir::TyKind::FnDef(fn_def_id, subst) => {
+                let callable_def = from_chalk(db, fn_def_id);
+                apply_ty_from_chalk(db, TypeCtor::FnDef(callable_def), subst)
+            }
+
+            chalk_ir::TyKind::Closure(id, subst) => {
+                let id: crate::db::ClosureId = id.into();
+                let (def, expr) = db.lookup_intern_closure(id);
+                apply_ty_from_chalk(db, TypeCtor::Closure { def, expr }, subst)
+            }
+
+            chalk_ir::TyKind::Foreign(foreign_def_id) => Ty::simple(TypeCtor::ForeignType(
+                from_chalk::<TypeAliasAsForeignType, _>(db, foreign_def_id).0,
+            )),
+            chalk_ir::TyKind::Generator(_, _) => unimplemented!(), // FIXME
+            chalk_ir::TyKind::GeneratorWitness(_, _) => unimplemented!(), // FIXME
         }
     }
 }
 
-const FAKE_PLACEHOLDER: PlaceholderIndex =
-    PlaceholderIndex { ui: UniverseIndex::ROOT, idx: usize::MAX };
+fn apply_ty_from_chalk(
+    db: &dyn HirDatabase,
+    ctor: TypeCtor,
+    subst: chalk_ir::Substitution<Interner>,
+) -> Ty {
+    Ty::Apply(ApplicationTy { ctor, parameters: from_chalk(db, subst) })
+}
 
 /// We currently don't model lifetimes, but Chalk does. So, we have to insert a
 /// fake lifetime here, because Chalks built-in logic may expect it to be there.
@@ -172,57 +283,22 @@ fn ref_to_chalk(
     subst: Substs,
 ) -> chalk_ir::Ty<Interner> {
     let arg = subst[0].clone().to_chalk(db);
-    let lifetime = FAKE_PLACEHOLDER.to_lifetime(&Interner);
-    chalk_ir::ApplicationTy {
-        name: TypeName::Ref(mutability.to_chalk(db)),
-        substitution: chalk_ir::Substitution::from_iter(
-            &Interner,
-            vec![lifetime.cast(&Interner), arg.cast(&Interner)],
-        ),
-    }
-    .intern(&Interner)
-}
-
-/// Here we remove the lifetime from the type we got from Chalk.
-fn ref_from_chalk(
-    db: &dyn HirDatabase,
-    mutability: chalk_ir::Mutability,
-    subst: chalk_ir::Substitution<Interner>,
-) -> Ty {
-    let tys = subst
-        .iter(&Interner)
-        .filter_map(|p| Some(from_chalk(db, p.ty(&Interner)?.clone())))
-        .collect();
-    Ty::apply(TypeCtor::Ref(from_chalk(db, mutability)), Substs(tys))
+    let lifetime = LifetimeData::Static.intern(&Interner);
+    chalk_ir::TyKind::Ref(mutability.to_chalk(db), lifetime, arg).intern(&Interner)
 }
 
 /// We currently don't model constants, but Chalk does. So, we have to insert a
 /// fake constant here, because Chalks built-in logic may expect it to be there.
 fn array_to_chalk(db: &dyn HirDatabase, subst: Substs) -> chalk_ir::Ty<Interner> {
     let arg = subst[0].clone().to_chalk(db);
-    let usize_ty = chalk_ir::ApplicationTy {
-        name: TypeName::Scalar(Scalar::Uint(chalk_ir::UintTy::Usize)),
-        substitution: chalk_ir::Substitution::empty(&Interner),
+    let usize_ty =
+        chalk_ir::TyKind::Scalar(Scalar::Uint(chalk_ir::UintTy::Usize)).intern(&Interner);
+    let const_ = chalk_ir::ConstData {
+        ty: usize_ty,
+        value: chalk_ir::ConstValue::Concrete(chalk_ir::ConcreteConst { interned: () }),
     }
     .intern(&Interner);
-    let const_ = FAKE_PLACEHOLDER.to_const(&Interner, usize_ty);
-    chalk_ir::ApplicationTy {
-        name: TypeName::Array,
-        substitution: chalk_ir::Substitution::from_iter(
-            &Interner,
-            vec![arg.cast(&Interner), const_.cast(&Interner)],
-        ),
-    }
-    .intern(&Interner)
-}
-
-/// Here we remove the const from the type we got from Chalk.
-fn array_from_chalk(db: &dyn HirDatabase, subst: chalk_ir::Substitution<Interner>) -> Ty {
-    let tys = subst
-        .iter(&Interner)
-        .filter_map(|p| Some(from_chalk(db, p.ty(&Interner)?.clone())))
-        .collect();
-    Ty::apply(TypeCtor::Array, Substs(tys))
+    chalk_ir::TyKind::Array(arg, const_).intern(&Interner)
 }
 
 impl ToChalk for Substs {
@@ -287,124 +363,6 @@ impl ToChalk for OpaqueTyId {
     }
 }
 
-impl ToChalk for TypeCtor {
-    type Chalk = TypeName<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> TypeName<Interner> {
-        match self {
-            TypeCtor::AssociatedType(type_alias) => {
-                let assoc_type = TypeAliasAsAssocType(type_alias);
-                let assoc_type_id = assoc_type.to_chalk(db);
-                TypeName::AssociatedType(assoc_type_id)
-            }
-
-            TypeCtor::OpaqueType(impl_trait_id) => {
-                let id = impl_trait_id.to_chalk(db);
-                TypeName::OpaqueType(id)
-            }
-
-            TypeCtor::ForeignType(type_alias) => {
-                let foreign_type = TypeAliasAsForeignType(type_alias);
-                let foreign_type_id = foreign_type.to_chalk(db);
-                TypeName::Foreign(foreign_type_id)
-            }
-
-            TypeCtor::Bool => TypeName::Scalar(Scalar::Bool),
-            TypeCtor::Char => TypeName::Scalar(Scalar::Char),
-            TypeCtor::Int(int_ty) => TypeName::Scalar(int_ty_to_chalk(int_ty)),
-            TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 }) => {
-                TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F32))
-            }
-            TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 }) => {
-                TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F64))
-            }
-
-            TypeCtor::Tuple { cardinality } => TypeName::Tuple(cardinality.into()),
-            TypeCtor::RawPtr(mutability) => TypeName::Raw(mutability.to_chalk(db)),
-            TypeCtor::Slice => TypeName::Slice,
-            TypeCtor::Array => TypeName::Array,
-            TypeCtor::Ref(mutability) => TypeName::Ref(mutability.to_chalk(db)),
-            TypeCtor::Str => TypeName::Str,
-            TypeCtor::FnDef(callable_def) => {
-                let id = callable_def.to_chalk(db);
-                TypeName::FnDef(id)
-            }
-            TypeCtor::Never => TypeName::Never,
-
-            TypeCtor::Closure { def, expr } => {
-                let closure_id = db.intern_closure((def, expr));
-                TypeName::Closure(closure_id.into())
-            }
-
-            TypeCtor::Adt(adt_id) => TypeName::Adt(chalk_ir::AdtId(adt_id)),
-
-            TypeCtor::FnPtr { .. } => {
-                // This should not be reached, since Chalk doesn't represent
-                // function pointers with TypeName
-                unreachable!()
-            }
-        }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, type_name: TypeName<Interner>) -> TypeCtor {
-        match type_name {
-            TypeName::Adt(struct_id) => TypeCtor::Adt(struct_id.0),
-            TypeName::AssociatedType(type_id) => {
-                TypeCtor::AssociatedType(from_chalk::<TypeAliasAsAssocType, _>(db, type_id).0)
-            }
-            TypeName::OpaqueType(opaque_type_id) => {
-                TypeCtor::OpaqueType(from_chalk(db, opaque_type_id))
-            }
-
-            TypeName::Scalar(Scalar::Bool) => TypeCtor::Bool,
-            TypeName::Scalar(Scalar::Char) => TypeCtor::Char,
-            TypeName::Scalar(Scalar::Int(int_ty)) => TypeCtor::Int(IntTy {
-                signedness: Signedness::Signed,
-                bitness: bitness_from_chalk_int(int_ty),
-            }),
-            TypeName::Scalar(Scalar::Uint(uint_ty)) => TypeCtor::Int(IntTy {
-                signedness: Signedness::Unsigned,
-                bitness: bitness_from_chalk_uint(uint_ty),
-            }),
-            TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F32)) => {
-                TypeCtor::Float(FloatTy { bitness: FloatBitness::X32 })
-            }
-            TypeName::Scalar(Scalar::Float(chalk_ir::FloatTy::F64)) => {
-                TypeCtor::Float(FloatTy { bitness: FloatBitness::X64 })
-            }
-            TypeName::Tuple(cardinality) => TypeCtor::Tuple { cardinality: cardinality as u16 },
-            TypeName::Raw(mutability) => TypeCtor::RawPtr(from_chalk(db, mutability)),
-            TypeName::Slice => TypeCtor::Slice,
-            TypeName::Ref(mutability) => TypeCtor::Ref(from_chalk(db, mutability)),
-            TypeName::Str => TypeCtor::Str,
-            TypeName::Never => TypeCtor::Never,
-
-            TypeName::FnDef(fn_def_id) => {
-                let callable_def = from_chalk(db, fn_def_id);
-                TypeCtor::FnDef(callable_def)
-            }
-            TypeName::Array => TypeCtor::Array,
-
-            TypeName::Closure(id) => {
-                let id: crate::db::ClosureId = id.into();
-                let (def, expr) = db.lookup_intern_closure(id);
-                TypeCtor::Closure { def, expr }
-            }
-
-            TypeName::Foreign(foreign_def_id) => {
-                TypeCtor::ForeignType(from_chalk::<TypeAliasAsForeignType, _>(db, foreign_def_id).0)
-            }
-
-            TypeName::Error => {
-                // this should not be reached, since we don't represent TypeName::Error with TypeCtor
-                unreachable!()
-            }
-            TypeName::Generator(_) => unimplemented!(), // FIXME
-            TypeName::GeneratorWitness(_) => unimplemented!(), // FIXME
-        }
-    }
-}
-
 fn bitness_from_chalk_uint(uint_ty: chalk_ir::UintTy) -> IntBitness {
     use chalk_ir::UintTy;
 
@@ -506,7 +464,7 @@ impl ToChalk for CallableDefId {
     }
 }
 
-pub struct TypeAliasAsAssocType(pub TypeAliasId);
+pub(crate) struct TypeAliasAsAssocType(pub(crate) TypeAliasId);
 
 impl ToChalk for TypeAliasAsAssocType {
     type Chalk = AssocTypeId;
@@ -520,7 +478,7 @@ impl ToChalk for TypeAliasAsAssocType {
     }
 }
 
-pub struct TypeAliasAsForeignType(pub TypeAliasId);
+pub(crate) struct TypeAliasAsForeignType(pub(crate) TypeAliasId);
 
 impl ToChalk for TypeAliasAsForeignType {
     type Chalk = ForeignDefId;
@@ -534,7 +492,7 @@ impl ToChalk for TypeAliasAsForeignType {
     }
 }
 
-pub struct TypeAliasAsValue(pub TypeAliasId);
+pub(crate) struct TypeAliasAsValue(pub(crate) TypeAliasId);
 
 impl ToChalk for TypeAliasAsValue {
     type Chalk = AssociatedTyValueId;
@@ -676,9 +634,9 @@ where
             .kinds
             .iter()
             .map(|k| match k {
-                TyKind::General => chalk_ir::TyKind::General,
-                TyKind::Integer => chalk_ir::TyKind::Integer,
-                TyKind::Float => chalk_ir::TyKind::Float,
+                TyKind::General => chalk_ir::TyVariableKind::General,
+                TyKind::Integer => chalk_ir::TyVariableKind::Integer,
+                TyKind::Float => chalk_ir::TyVariableKind::Float,
             })
             .map(|tk| {
                 chalk_ir::CanonicalVarKind::new(
@@ -699,9 +657,9 @@ where
             .iter(&Interner)
             .map(|k| match k.kind {
                 chalk_ir::VariableKind::Ty(tk) => match tk {
-                    chalk_ir::TyKind::General => TyKind::General,
-                    chalk_ir::TyKind::Integer => TyKind::Integer,
-                    chalk_ir::TyKind::Float => TyKind::Float,
+                    chalk_ir::TyVariableKind::General => TyKind::General,
+                    chalk_ir::TyVariableKind::Integer => TyKind::Integer,
+                    chalk_ir::TyVariableKind::Float => TyKind::Float,
                 },
                 chalk_ir::VariableKind::Lifetime => panic!("unexpected lifetime from Chalk"),
                 chalk_ir::VariableKind::Const(_) => panic!("unexpected const from Chalk"),
@@ -767,7 +725,8 @@ where
     chalk_ir::Binders::new(
         chalk_ir::VariableKinds::from_iter(
             &Interner,
-            std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyKind::General)).take(num_vars),
+            std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General))
+                .take(num_vars),
         ),
         value,
     )
diff --git a/crates/hir_ty/src/traits/chalk/tls.rs b/crates/hir_ty/src/traits/chalk/tls.rs
index b4568cff6..75b16172e 100644
--- a/crates/hir_ty/src/traits/chalk/tls.rs
+++ b/crates/hir_ty/src/traits/chalk/tls.rs
@@ -1,114 +1,32 @@
 //! Implementation of Chalk debug helper functions using TLS.
 use std::fmt;
 
-use chalk_ir::{AliasTy, GenericArg, Goal, Goals, Lifetime, ProgramClauseImplication, TypeName};
+use chalk_ir::{AliasTy, GenericArg, Goal, Goals, Lifetime, ProgramClauseImplication};
 use itertools::Itertools;
 
 use super::{from_chalk, Interner, TypeAliasAsAssocType};
-use crate::{db::HirDatabase, CallableDefId, TypeCtor};
-use hir_def::{AdtId, AssocContainerId, DefWithBodyId, Lookup, TypeAliasId};
+use crate::{db::HirDatabase, CallableDefId};
+use hir_def::{AdtId, AssocContainerId, Lookup, TypeAliasId};
 
-pub use unsafe_tls::{set_current_program, with_current_program};
+pub(crate) use unsafe_tls::{set_current_program, with_current_program};
 
-pub struct DebugContext<'a>(&'a dyn HirDatabase);
+pub(crate) struct DebugContext<'a>(&'a dyn HirDatabase);
 
 impl DebugContext<'_> {
-    pub fn debug_struct_id(
+    pub(crate) fn debug_struct_id(
         &self,
         id: super::AdtId,
         f: &mut fmt::Formatter<'_>,
     ) -> Result<(), fmt::Error> {
-        let type_ctor: TypeCtor = from_chalk(self.0, TypeName::Adt(id));
-        match type_ctor {
-            TypeCtor::Bool => write!(f, "bool")?,
-            TypeCtor::Char => write!(f, "char")?,
-            TypeCtor::Int(t) => write!(f, "{}", t)?,
-            TypeCtor::Float(t) => write!(f, "{}", t)?,
-            TypeCtor::Str => write!(f, "str")?,
-            TypeCtor::Slice => write!(f, "slice")?,
-            TypeCtor::Array => write!(f, "array")?,
-            TypeCtor::RawPtr(m) => write!(f, "*{}", m.as_keyword_for_ptr())?,
-            TypeCtor::Ref(m) => write!(f, "&{}", m.as_keyword_for_ref())?,
-            TypeCtor::Never => write!(f, "!")?,
-            TypeCtor::Tuple { .. } => {
-                write!(f, "()")?;
-            }
-            TypeCtor::FnPtr { .. } => {
-                write!(f, "fn")?;
-            }
-            TypeCtor::FnDef(def) => {
-                let name = match def {
-                    CallableDefId::FunctionId(ff) => self.0.function_data(ff).name.clone(),
-                    CallableDefId::StructId(s) => self.0.struct_data(s).name.clone(),
-                    CallableDefId::EnumVariantId(e) => {
-                        let enum_data = self.0.enum_data(e.parent);
-                        enum_data.variants[e.local_id].name.clone()
-                    }
-                };
-                match def {
-                    CallableDefId::FunctionId(_) => write!(f, "{{fn {}}}", name)?,
-                    CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {
-                        write!(f, "{{ctor {}}}", name)?
-                    }
-                }
-            }
-            TypeCtor::Adt(def_id) => {
-                let name = match def_id {
-                    AdtId::StructId(it) => self.0.struct_data(it).name.clone(),
-                    AdtId::UnionId(it) => self.0.union_data(it).name.clone(),
-                    AdtId::EnumId(it) => self.0.enum_data(it).name.clone(),
-                };
-                write!(f, "{}", name)?;
-            }
-            TypeCtor::AssociatedType(type_alias) => {
-                let trait_ = match type_alias.lookup(self.0.upcast()).container {
-                    AssocContainerId::TraitId(it) => it,
-                    _ => panic!("not an associated type"),
-                };
-                let trait_name = self.0.trait_data(trait_).name.clone();
-                let name = self.0.type_alias_data(type_alias).name.clone();
-                write!(f, "{}::{}", trait_name, name)?;
-            }
-            TypeCtor::OpaqueType(opaque_ty_id) => match opaque_ty_id {
-                crate::OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
-                    write!(f, "{{impl trait {} of {:?}}}", idx, func)?;
-                }
-                crate::OpaqueTyId::AsyncBlockTypeImplTrait(def, idx) => {
-                    write!(f, "{{impl trait of async block {} of {:?}}}", idx.into_raw(), def)?;
-                }
-            },
-            TypeCtor::ForeignType(type_alias) => {
-                let name = self.0.type_alias_data(type_alias).name.clone();
-                write!(f, "{}", name)?;
-            }
-            TypeCtor::Closure { def, expr } => {
-                write!(f, "{{closure {:?} in ", expr.into_raw())?;
-                match def {
-                    DefWithBodyId::FunctionId(func) => {
-                        write!(f, "fn {}", self.0.function_data(func).name)?
-                    }
-                    DefWithBodyId::StaticId(s) => {
-                        if let Some(name) = self.0.static_data(s).name.as_ref() {
-                            write!(f, "body of static {}", name)?;
-                        } else {
-                            write!(f, "body of unnamed static {:?}", s)?;
-                        }
-                    }
-                    DefWithBodyId::ConstId(c) => {
-                        if let Some(name) = self.0.const_data(c).name.as_ref() {
-                            write!(f, "body of const {}", name)?;
-                        } else {
-                            write!(f, "body of unnamed const {:?}", c)?;
-                        }
-                    }
-                };
-                write!(f, "}}")?;
-            }
-        }
-        Ok(())
+        let name = match id.0 {
+            AdtId::StructId(it) => self.0.struct_data(it).name.clone(),
+            AdtId::UnionId(it) => self.0.union_data(it).name.clone(),
+            AdtId::EnumId(it) => self.0.enum_data(it).name.clone(),
+        };
+        write!(f, "{}", name)
     }
 
-    pub fn debug_trait_id(
+    pub(crate) fn debug_trait_id(
         &self,
         id: super::TraitId,
         fmt: &mut fmt::Formatter<'_>,
@@ -118,7 +36,7 @@ impl DebugContext<'_> {
         write!(fmt, "{}", trait_data.name)
     }
 
-    pub fn debug_assoc_type_id(
+    pub(crate) fn debug_assoc_type_id(
         &self,
         id: super::AssocTypeId,
         fmt: &mut fmt::Formatter<'_>,
@@ -133,7 +51,7 @@ impl DebugContext<'_> {
         write!(fmt, "{}::{}", trait_data.name, type_alias_data.name)
     }
 
-    pub fn debug_opaque_ty_id(
+    pub(crate) fn debug_opaque_ty_id(
         &self,
         opaque_ty_id: chalk_ir::OpaqueTyId<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -141,7 +59,7 @@ impl DebugContext<'_> {
         fmt.debug_struct("OpaqueTyId").field("index", &opaque_ty_id.0).finish()
     }
 
-    pub fn debug_alias(
+    pub(crate) fn debug_alias(
         &self,
         alias_ty: &AliasTy<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -152,7 +70,7 @@ impl DebugContext<'_> {
         }
     }
 
-    pub fn debug_projection_ty(
+    pub(crate) fn debug_projection_ty(
         &self,
         projection_ty: &chalk_ir::ProjectionTy<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -177,7 +95,7 @@ impl DebugContext<'_> {
         write!(fmt, ">::{}", type_alias_data.name)
     }
 
-    pub fn debug_opaque_ty(
+    pub(crate) fn debug_opaque_ty(
         &self,
         opaque_ty: &chalk_ir::OpaqueTy<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -185,7 +103,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", opaque_ty.opaque_ty_id)
     }
 
-    pub fn debug_ty(
+    pub(crate) fn debug_ty(
         &self,
         ty: &chalk_ir::Ty<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -193,7 +111,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", ty.data(&Interner))
     }
 
-    pub fn debug_lifetime(
+    pub(crate) fn debug_lifetime(
         &self,
         lifetime: &Lifetime<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -201,7 +119,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", lifetime.data(&Interner))
     }
 
-    pub fn debug_generic_arg(
+    pub(crate) fn debug_generic_arg(
         &self,
         parameter: &GenericArg<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -209,7 +127,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", parameter.data(&Interner).inner_debug())
     }
 
-    pub fn debug_goal(
+    pub(crate) fn debug_goal(
         &self,
         goal: &Goal<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -218,7 +136,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", goal_data)
     }
 
-    pub fn debug_goals(
+    pub(crate) fn debug_goals(
         &self,
         goals: &Goals<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -226,7 +144,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", goals.debug(&Interner))
     }
 
-    pub fn debug_program_clause_implication(
+    pub(crate) fn debug_program_clause_implication(
         &self,
         pci: &ProgramClauseImplication<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -234,15 +152,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", pci.debug(&Interner))
     }
 
-    pub fn debug_application_ty(
-        &self,
-        application_ty: &chalk_ir::ApplicationTy<Interner>,
-        fmt: &mut fmt::Formatter<'_>,
-    ) -> Result<(), fmt::Error> {
-        write!(fmt, "{:?}", application_ty.debug(&Interner))
-    }
-
-    pub fn debug_substitution(
+    pub(crate) fn debug_substitution(
         &self,
         substitution: &chalk_ir::Substitution<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -250,7 +160,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", substitution.debug(&Interner))
     }
 
-    pub fn debug_separator_trait_ref(
+    pub(crate) fn debug_separator_trait_ref(
         &self,
         separator_trait_ref: &chalk_ir::SeparatorTraitRef<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -258,7 +168,7 @@ impl DebugContext<'_> {
         write!(fmt, "{:?}", separator_trait_ref.debug(&Interner))
     }
 
-    pub fn debug_fn_def_id(
+    pub(crate) fn debug_fn_def_id(
         &self,
         fn_def_id: chalk_ir::FnDefId<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -280,7 +190,7 @@ impl DebugContext<'_> {
         }
     }
 
-    pub fn debug_const(
+    pub(crate) fn debug_const(
         &self,
         _constant: &chalk_ir::Const<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -288,42 +198,42 @@ impl DebugContext<'_> {
         write!(fmt, "const")
     }
 
-    pub fn debug_variable_kinds(
+    pub(crate) fn debug_variable_kinds(
         &self,
         variable_kinds: &chalk_ir::VariableKinds<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         write!(fmt, "{:?}", variable_kinds.as_slice(&Interner))
     }
-    pub fn debug_variable_kinds_with_angles(
+    pub(crate) fn debug_variable_kinds_with_angles(
         &self,
         variable_kinds: &chalk_ir::VariableKinds<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         write!(fmt, "{:?}", variable_kinds.inner_debug(&Interner))
     }
-    pub fn debug_canonical_var_kinds(
+    pub(crate) fn debug_canonical_var_kinds(
         &self,
         canonical_var_kinds: &chalk_ir::CanonicalVarKinds<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         write!(fmt, "{:?}", canonical_var_kinds.as_slice(&Interner))
     }
-    pub fn debug_program_clause(
+    pub(crate) fn debug_program_clause(
         &self,
         clause: &chalk_ir::ProgramClause<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         write!(fmt, "{:?}", clause.data(&Interner))
     }
-    pub fn debug_program_clauses(
+    pub(crate) fn debug_program_clauses(
         &self,
         clauses: &chalk_ir::ProgramClauses<Interner>,
         fmt: &mut fmt::Formatter<'_>,
     ) -> fmt::Result {
         write!(fmt, "{:?}", clauses.as_slice(&Interner))
     }
-    pub fn debug_quantified_where_clauses(
+    pub(crate) fn debug_quantified_where_clauses(
         &self,
         clauses: &chalk_ir::QuantifiedWhereClauses<Interner>,
         fmt: &mut fmt::Formatter<'_>,
@@ -339,7 +249,7 @@ mod unsafe_tls {
 
     scoped_thread_local!(static PROGRAM: DebugContext);
 
-    pub fn with_current_program<R>(
+    pub(crate) fn with_current_program<R>(
         op: impl for<'a> FnOnce(Option<&'a DebugContext<'a>>) -> R,
     ) -> R {
         if PROGRAM.is_set() {
@@ -349,7 +259,7 @@ mod unsafe_tls {
         }
     }
 
-    pub fn set_current_program<OP, R>(p: &dyn HirDatabase, op: OP) -> R
+    pub(crate) fn set_current_program<OP, R>(p: &dyn HirDatabase, op: OP) -> R
     where
         OP: FnOnce() -> R,
     {