Rollup merge of #79951 - LeSeulArtichaut:ty-ir, r=nikomatsakis

Refractor a few more types to `rustc_type_ir`

In the continuation of #79169, ~~blocked on that PR~~.

This PR:
 - moves `IntVarValue`, `FloatVarValue`, `InferTy` (and friends) and `Variance`
 - creates the `IntTy`, `UintTy` and `FloatTy` enums in `rustc_type_ir`, based on their `ast` and `chalk_ir` equilavents, and uses them for types in the rest of the compiler.

~~I will split up that commit to make this easier to review and to have a better commit history.~~
EDIT: done, I split the PR in commits of 200-ish lines each

r? `````@nikomatsakis````` cc `````@jackh726`````

8 files changed, 24 insertions, 30 deletions

diff --git a/clippy_lints/src/bytecount.rs b/clippy_lints/src/bytecount.rs
index 38a0e27c4cf..ac9098a7584 100644
--- a/clippy_lints/src/bytecount.rs
+++ b/clippy_lints/src/bytecount.rs
@@ -2,11 +2,10 @@ use crate::utils::{
     contains_name, get_pat_name, match_type, paths, single_segment_path, snippet_with_applicability, span_lint_and_sugg,
 };
 use if_chain::if_chain;
-use rustc_ast::ast::UintTy;
 use rustc_errors::Applicability;
 use rustc_hir::{BinOpKind, BorrowKind, Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty;
+use rustc_middle::ty::{self, UintTy};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::sym;
 use rustc_span::Symbol;
diff --git a/clippy_lints/src/consts.rs b/clippy_lints/src/consts.rs
index 166eadf86c1..640cffd24a7 100644
--- a/clippy_lints/src/consts.rs
+++ b/clippy_lints/src/consts.rs
@@ -2,14 +2,14 @@
 
 use crate::utils::{clip, sext, unsext};
 use if_chain::if_chain;
-use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
+use rustc_ast::ast::{self, LitFloatType, LitKind};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{BinOp, BinOpKind, Block, Expr, ExprKind, HirId, QPath, UnOp};
 use rustc_lint::LateContext;
 use rustc_middle::mir::interpret::Scalar;
 use rustc_middle::ty::subst::{Subst, SubstsRef};
-use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt};
+use rustc_middle::ty::{self, FloatTy, ScalarInt, Ty, TyCtxt};
 use rustc_middle::{bug, span_bug};
 use rustc_span::symbol::Symbol;
 use std::cmp::Ordering::{self, Equal};
@@ -167,8 +167,8 @@ pub fn lit_to_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
         LitKind::Char(c) => Constant::Char(c),
         LitKind::Int(n, _) => Constant::Int(n),
         LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {
-            FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
-            FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
+            ast::FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
+            ast::FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
         },
         LitKind::Float(ref is, LitFloatType::Unsuffixed) => match ty.expect("type of float is known").kind() {
             ty::Float(FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()),
diff --git a/clippy_lints/src/enum_clike.rs b/clippy_lints/src/enum_clike.rs
index fb80f48a9cc..ae56a8ba5ab 100644
--- a/clippy_lints/src/enum_clike.rs
+++ b/clippy_lints/src/enum_clike.rs
@@ -3,10 +3,9 @@
 
 use crate::consts::{miri_to_const, Constant};
 use crate::utils::span_lint;
-use rustc_ast::ast::{IntTy, UintTy};
 use rustc_hir::{Item, ItemKind};
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty;
+use rustc_middle::ty::{self, IntTy, UintTy};
 use rustc_middle::ty::util::IntTypeExt;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use std::convert::TryFrom;
diff --git a/clippy_lints/src/float_literal.rs b/clippy_lints/src/float_literal.rs
index 1fe4461533b..be646cbe4d0 100644
--- a/clippy_lints/src/float_literal.rs
+++ b/clippy_lints/src/float_literal.rs
@@ -1,10 +1,10 @@
 use crate::utils::{numeric_literal, span_lint_and_sugg};
 use if_chain::if_chain;
-use rustc_ast::ast::{FloatTy, LitFloatType, LitKind};
+use rustc_ast::ast::{self, LitFloatType, LitKind};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty;
+use rustc_middle::ty::{self, FloatTy};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use std::fmt;
 
@@ -75,8 +75,8 @@ impl<'tcx> LateLintPass<'tcx> for FloatLiteral {
                 let digits = count_digits(&sym_str);
                 let max = max_digits(fty);
                 let type_suffix = match lit_float_ty {
-                    LitFloatType::Suffixed(FloatTy::F32) => Some("f32"),
-                    LitFloatType::Suffixed(FloatTy::F64) => Some("f64"),
+                    LitFloatType::Suffixed(ast::FloatTy::F32) => Some("f32"),
+                    LitFloatType::Suffixed(ast::FloatTy::F64) => Some("f64"),
                     LitFloatType::Unsuffixed => None
                 };
                 let (is_whole, mut float_str) = match fty {
diff --git a/clippy_lints/src/mutex_atomic.rs b/clippy_lints/src/mutex_atomic.rs
index ea986874291..40b236493a3 100644
--- a/clippy_lints/src/mutex_atomic.rs
+++ b/clippy_lints/src/mutex_atomic.rs
@@ -3,7 +3,6 @@
 //! This lint is **warn** by default
 
 use crate::utils::{is_type_diagnostic_item, span_lint};
-use rustc_ast::ast;
 use rustc_hir::Expr;
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::{self, Ty};
@@ -77,8 +76,8 @@ impl<'tcx> LateLintPass<'tcx> for Mutex {
                         atomic_name
                     );
                     match *mutex_param.kind() {
-                        ty::Uint(t) if t != ast::UintTy::Usize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
-                        ty::Int(t) if t != ast::IntTy::Isize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+                        ty::Uint(t) if t != ty::UintTy::Usize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
+                        ty::Int(t) if t != ty::IntTy::Isize => span_lint(cx, MUTEX_INTEGER, expr.span, &msg),
                         _ => span_lint(cx, MUTEX_ATOMIC, expr.span, &msg),
                     };
                 }
diff --git a/clippy_lints/src/transmute.rs b/clippy_lints/src/transmute.rs
index b0909f73177..d977cea4da5 100644
--- a/clippy_lints/src/transmute.rs
+++ b/clippy_lints/src/transmute.rs
@@ -443,7 +443,7 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                             );
                         },
                     ),
-                    (ty::Int(ast::IntTy::I32) | ty::Uint(ast::UintTy::U32), &ty::Char) => {
+                    (ty::Int(ty::IntTy::I32) | ty::Uint(ty::UintTy::U32), &ty::Char) => {
                         span_lint_and_then(
                             cx,
                             TRANSMUTE_INT_TO_CHAR,
@@ -468,7 +468,7 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                     (ty::Ref(_, ty_from, from_mutbl), ty::Ref(_, ty_to, to_mutbl)) => {
                         if_chain! {
                             if let (&ty::Slice(slice_ty), &ty::Str) = (&ty_from.kind(), &ty_to.kind());
-                            if let ty::Uint(ast::UintTy::U8) = slice_ty.kind();
+                            if let ty::Uint(ty::UintTy::U8) = slice_ty.kind();
                             if from_mutbl == to_mutbl;
                             then {
                                 let postfix = if *from_mutbl == Mutability::Mut {
@@ -536,7 +536,7 @@ impl<'tcx> LateLintPass<'tcx> for Transmute {
                             }
                         },
                     ),
-                    (ty::Int(ast::IntTy::I8) | ty::Uint(ast::UintTy::U8), ty::Bool) => {
+                    (ty::Int(ty::IntTy::I8) | ty::Uint(ty::UintTy::U8), ty::Bool) => {
                         span_lint_and_then(
                             cx,
                             TRANSMUTE_INT_TO_BOOL,
diff --git a/clippy_lints/src/types.rs b/clippy_lints/src/types.rs
index 3b5a83d2a0b..17cef0af3e9 100644
--- a/clippy_lints/src/types.rs
+++ b/clippy_lints/src/types.rs
@@ -5,7 +5,7 @@ use std::cmp::Ordering;
 use std::collections::BTreeMap;
 
 use if_chain::if_chain;
-use rustc_ast::{FloatTy, IntTy, LitFloatType, LitIntType, LitKind, UintTy};
+use rustc_ast::{LitFloatType, LitIntType, LitKind};
 use rustc_errors::{Applicability, DiagnosticBuilder};
 use rustc_hir as hir;
 use rustc_hir::intravisit::{walk_body, walk_expr, walk_ty, FnKind, NestedVisitorMap, Visitor};
@@ -18,7 +18,7 @@ use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::hir::map::Map;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::TypeFoldable;
-use rustc_middle::ty::{self, InferTy, Ty, TyCtxt, TyS, TypeAndMut, TypeckResults};
+use rustc_middle::ty::{self, FloatTy, InferTy, IntTy, Ty, TyCtxt, TyS, TypeAndMut, TypeckResults, UintTy};
 use rustc_semver::RustcVersion;
 use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
@@ -1106,9 +1106,7 @@ fn is_empty_block(expr: &Expr<'_>) -> bool {
         expr.kind,
         ExprKind::Block(
             Block {
-                stmts: &[],
-                expr: None,
-                ..
+                stmts: &[], expr: None, ..
             },
             _,
         )
diff --git a/clippy_lints/src/utils/mod.rs b/clippy_lints/src/utils/mod.rs
index 9b262517a98..46b2b06d1a2 100644
--- a/clippy_lints/src/utils/mod.rs
+++ b/clippy_lints/src/utils/mod.rs
@@ -35,7 +35,6 @@ use std::mem;
 
 use if_chain::if_chain;
 use rustc_ast::ast::{self, Attribute, LitKind};
-use rustc_attr as attr;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::Applicability;
 use rustc_hir as hir;
@@ -1224,27 +1223,27 @@ pub fn get_arg_name(pat: &Pat<'_>) -> Option<Symbol> {
     }
 }
 
-pub fn int_bits(tcx: TyCtxt<'_>, ity: ast::IntTy) -> u64 {
-    Integer::from_attr(&tcx, attr::IntType::SignedInt(ity)).size().bits()
+pub fn int_bits(tcx: TyCtxt<'_>, ity: ty::IntTy) -> u64 {
+    Integer::from_int_ty(&tcx, ity).size().bits()
 }
 
 #[allow(clippy::cast_possible_wrap)]
 /// Turn a constant int byte representation into an i128
-pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: ast::IntTy) -> i128 {
+pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: ty::IntTy) -> i128 {
     let amt = 128 - int_bits(tcx, ity);
     ((u as i128) << amt) >> amt
 }
 
 #[allow(clippy::cast_sign_loss)]
 /// clip unused bytes
-pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: ast::IntTy) -> u128 {
+pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: ty::IntTy) -> u128 {
     let amt = 128 - int_bits(tcx, ity);
     ((u as u128) << amt) >> amt
 }
 
 /// clip unused bytes
-pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: ast::UintTy) -> u128 {
-    let bits = Integer::from_attr(&tcx, attr::IntType::UnsignedInt(ity)).size().bits();
+pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: ty::UintTy) -> u128 {
+    let bits = Integer::from_uint_ty(&tcx, ity).size().bits();
     let amt = 128 - bits;
     (u << amt) >> amt
 }