compiler: remove rustc_abi::lookup and AbiUnsupported

These can be entirely replaced by the FromStr implementation.

Author: workingjubilee

compiler/rustc_abi/src/extern_abi.rs

@@ -1,7 +1,6 @@
 use std::cmp::Ordering;
 use std::fmt;
 use std::hash::{Hash, Hasher};
-use std::str::FromStr;
 
 #[cfg(feature = "nightly")]
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableOrd};
@@ -101,6 +100,7 @@ macro_rules! abi_impls {
     }
 }
 
+#[derive(Debug)]
 pub enum AbiFromStrErr {
     Unknown,
 }
@@ -214,13 +214,6 @@ impl ExternAbi {
     }
 }
 
-#[derive(Copy, Clone, Debug)]
-pub struct AbiUnsupported {}
-/// Returns the ABI with the given name (if any).
-pub fn lookup(name: &str) -> Result<Abi, AbiUnsupported> {
-    ExternAbi::from_str(name).map_err(|_| AbiUnsupported {})
-}
-
 pub fn all_names() -> Vec<&'static str> {
     ExternAbi::ALL_VARIANTS.iter().map(|abi| abi.as_str()).collect()
 }

compiler/rustc_abi/src/extern_abi/tests.rs

@@ -1,24 +1,25 @@
 use std::assert_matches::assert_matches;
+use std::str::FromStr;
 
 use super::*;
 
 #[allow(non_snake_case)]
 #[test]
 fn lookup_Rust() {
-    let abi = lookup("Rust");
+    let abi = ExternAbi::from_str("Rust");
     assert!(abi.is_ok() && abi.unwrap().as_str() == "Rust");
 }
 
 #[test]
 fn lookup_cdecl() {
-    let abi = lookup("cdecl");
+    let abi = ExternAbi::from_str("cdecl");
     assert!(abi.is_ok() && abi.unwrap().as_str() == "cdecl");
 }
 
 #[test]
 fn lookup_baz() {
-    let abi = lookup("baz");
-    assert_matches!(abi, Err(AbiUnsupported {}));
+    let abi = ExternAbi::from_str("baz");
+    assert_matches!(abi, Err(AbiFromStrErr::Unknown));
 }
 
 #[test]

compiler/rustc_abi/src/lib.rs

@@ -62,7 +62,7 @@ mod tests;
 mod extern_abi;
 
 pub use callconv::{Heterogeneous, HomogeneousAggregate, Reg, RegKind};
-pub use extern_abi::{AbiUnsupported, ExternAbi, all_names, lookup};
+pub use extern_abi::{ExternAbi, all_names};
 #[cfg(feature = "nightly")]
 pub use layout::{FIRST_VARIANT, FieldIdx, Layout, TyAbiInterface, TyAndLayout, VariantIdx};
 pub use layout::{LayoutCalculator, LayoutCalculatorError};
@@ -1178,10 +1178,13 @@ impl Scalar {
     #[inline]
     pub fn is_bool(&self) -> bool {
         use Integer::*;
-        matches!(self, Scalar::Initialized {
-            value: Primitive::Int(I8, false),
-            valid_range: WrappingRange { start: 0, end: 1 }
-        })
+        matches!(
+            self,
+            Scalar::Initialized {
+                value: Primitive::Int(I8, false),
+                valid_range: WrappingRange { start: 0, end: 1 }
+            }
+        )
     }
 
     /// Get the primitive representation of this type, ignoring the valid range and whether the

compiler/rustc_ast_lowering/src/item.rs

@@ -1475,7 +1475,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
     pub(super) fn lower_abi(&mut self, abi_str: StrLit) -> ExternAbi {
         let ast::StrLit { symbol_unescaped, span, .. } = abi_str;
-        let extern_abi = rustc_abi::lookup(symbol_unescaped.as_str()).unwrap_or_else(|_| {
+        let extern_abi = symbol_unescaped.as_str().parse().unwrap_or_else(|_| {
             self.error_on_invalid_abi(abi_str);
             ExternAbi::Rust
         });