Deduplicate IntTy/UintTy/FloatTy.

There are identical definitions in `rustc_type_ir` and `rustc_ast`. This
commit removes them and places a single definition in `rustc_ast_ir`.
This requires adding `rust_span` as a dependency of `rustc_ast_ir`, but
means a bunch of silly conversion functions can be removed.

The one annoying wrinkle is that the old version had differences in
their `Debug` impls, e.g. one printed `u32` while the other printed
`U32`. Some compiler error messages rely on the former (yuk), and some
clippy output depends on the latter. So the commit also changes clippy
to not rely on `Debug` and just implement what it needs itself.

Author: nnethercote

clippy_lints/src/float_literal.rs

@@ -1,6 +1,6 @@
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::numeric_literal;
-use rustc_ast::ast::{self, LitFloatType, LitKind};
+use rustc_ast::ast::{LitFloatType, LitKind};
 use rustc_errors::Applicability;
 use rustc_hir as hir;
 use rustc_lint::{LateContext, LateLintPass};
@@ -75,10 +75,10 @@ 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(ast::FloatTy::F16) => Some("f16"),
-                LitFloatType::Suffixed(ast::FloatTy::F32) => Some("f32"),
-                LitFloatType::Suffixed(ast::FloatTy::F64) => Some("f64"),
-                LitFloatType::Suffixed(ast::FloatTy::F128) => Some("f128"),
+                LitFloatType::Suffixed(FloatTy::F16) => Some("f16"),
+                LitFloatType::Suffixed(FloatTy::F32) => Some("f32"),
+                LitFloatType::Suffixed(FloatTy::F64) => Some("f64"),
+                LitFloatType::Suffixed(FloatTy::F128) => Some("f128"),
                 LitFloatType::Unsuffixed => None,
             };
             let (is_whole, is_inf, mut float_str) = match fty {

clippy_lints/src/utils/author.rs

@@ -9,6 +9,7 @@ use rustc_hir::{
     FnRetTy, HirId, Lit, PatExprKind, PatKind, QPath, StmtKind, StructTailExpr,
 };
 use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_middle::ty::{FloatTy, IntTy, UintTy};
 use rustc_session::declare_lint_pass;
 use rustc_span::symbol::{Ident, Symbol};
 use std::cell::Cell;
@@ -337,15 +338,43 @@ impl<'a, 'tcx> PrintVisitor<'a, 'tcx> {
             LitKind::Byte(b) => kind!("Byte({b})"),
             LitKind::Int(i, suffix) => {
                 let int_ty = match suffix {
-                    LitIntType::Signed(int_ty) => format!("LitIntType::Signed(IntTy::{int_ty:?})"),
-                    LitIntType::Unsigned(uint_ty) => format!("LitIntType::Unsigned(UintTy::{uint_ty:?})"),
+                    LitIntType::Signed(int_ty) => {
+                        let t = match int_ty {
+                            IntTy::Isize => "Isize",
+                            IntTy::I8 => "I8",
+                            IntTy::I16 => "I16",
+                            IntTy::I32 => "I32",
+                            IntTy::I64 => "I64",
+                            IntTy::I128 => "I128",
+                        };
+                        format!("LitIntType::Signed(IntTy::{t})")
+                    }
+                    LitIntType::Unsigned(uint_ty) => {
+                        let t = match uint_ty {
+                            UintTy::Usize => "Usize",
+                            UintTy::U8 => "U8",
+                            UintTy::U16 => "U16",
+                            UintTy::U32 => "U32",
+                            UintTy::U64 => "U64",
+                            UintTy::U128 => "U128",
+                        };
+                        format!("LitIntType::Unsigned(UintTy::{t})")
+                    }
                     LitIntType::Unsuffixed => String::from("LitIntType::Unsuffixed"),
                 };
                 kind!("Int({i}, {int_ty})");
             },
             LitKind::Float(_, suffix) => {
                 let float_ty = match suffix {
-                    LitFloatType::Suffixed(suffix_ty) => format!("LitFloatType::Suffixed(FloatTy::{suffix_ty:?})"),
+                    LitFloatType::Suffixed(suffix_ty) => {
+                        let t = match suffix_ty {
+                            FloatTy::F16 => "F16",
+                            FloatTy::F32 => "F32",
+                            FloatTy::F64 => "F64",
+                            FloatTy::F128 => "F128",
+                        };
+                        format!("LitFloatType::Suffixed(FloatTy::{t})")
+                    }
                     LitFloatType::Unsuffixed => String::from("LitFloatType::Unsuffixed"),
                 };
                 kind!("Float(_, {float_ty})");

clippy_utils/src/consts.rs

@@ -10,7 +10,7 @@ use crate::{clip, is_direct_expn_of, sext, unsext};
 use rustc_abi::Size;
 use rustc_apfloat::Float;
 use rustc_apfloat::ieee::{Half, Quad};
-use rustc_ast::ast::{self, LitFloatType, LitKind};
+use rustc_ast::ast::{LitFloatType, LitKind};
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::{
     BinOpKind, Block, ConstBlock, Expr, ExprKind, HirId, Item, ItemKind, Node, PatExpr, PatExprKind, QPath, UnOp,
@@ -309,10 +309,10 @@ pub fn lit_to_mir_constant<'tcx>(lit: &LitKind, ty: Option<Ty<'tcx>>) -> Constan
         LitKind::Int(n, _) => Constant::Int(n.get()),
         LitKind::Float(ref is, LitFloatType::Suffixed(fty)) => match fty {
             // FIXME(f16_f128): just use `parse()` directly when available for `f16`/`f128`
-            ast::FloatTy::F16 => Constant::parse_f16(is.as_str()),
-            ast::FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
-            ast::FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
-            ast::FloatTy::F128 => Constant::parse_f128(is.as_str()),
+            FloatTy::F16 => Constant::parse_f16(is.as_str()),
+            FloatTy::F32 => Constant::F32(is.as_str().parse().unwrap()),
+            FloatTy::F64 => Constant::F64(is.as_str().parse().unwrap()),
+            FloatTy::F128 => Constant::parse_f128(is.as_str()),
         },
         LitKind::Float(ref is, LitFloatType::Unsuffixed) => match ty.expect("type of float is known").kind() {
             ty::Float(FloatTy::F16) => Constant::parse_f16(is.as_str()),