Remove (lots of) dead code

Found with https://github.com/est31/warnalyzer.

Dubious changes:
- Is anyone else using rustc_apfloat? I feel weird completely deleting
  x87 support.
- Maybe some of the dead code in rustc_data_structures, in case someone
  wants to use it in the future?
- Don't change rustc_serialize

  I plan to scrap most of the json module in the near future (see
  rust-lang/compiler-team#418) and fixing the
  tests needed more work than I expected.

TODO: check if any of the comments on the deleted code should be kept.

Author: jyn514

compiler/rustc_arena/src/lib.rs

@@ -236,26 +236,6 @@ impl<T> TypedArena<T> {
         start_ptr
     }
 
-    /// Allocates a slice of objects that are copied into the `TypedArena`, returning a mutable
-    /// reference to it. Will panic if passed a zero-sized types.
-    ///
-    /// Panics:
-    ///
-    ///  - Zero-sized types
-    ///  - Zero-length slices
-    #[inline]
-    pub fn alloc_slice(&self, slice: &[T]) -> &mut [T]
-    where
-        T: Copy,
-    {
-        unsafe {
-            let len = slice.len();
-            let start_ptr = self.alloc_raw_slice(len);
-            slice.as_ptr().copy_to_nonoverlapping(start_ptr, len);
-            slice::from_raw_parts_mut(start_ptr, len)
-        }
-    }
-
     #[inline]
     pub fn alloc_from_iter<I: IntoIterator<Item = T>>(&self, iter: I) -> &mut [T] {
         assert!(mem::size_of::<T>() != 0);

compiler/rustc_ast/src/ast.rs

@@ -762,14 +762,6 @@ pub enum Mutability {
 }
 
 impl Mutability {
-    /// Returns `MutMutable` only if both `self` and `other` are mutable.
-    pub fn and(self, other: Self) -> Self {
-        match self {
-            Mutability::Mut => other,
-            Mutability::Not => Mutability::Not,
-        }
-    }
-
     pub fn invert(self) -> Self {
         match self {
             Mutability::Mut => Mutability::Not,
@@ -1722,13 +1714,6 @@ impl FloatTy {
             FloatTy::F64 => sym::f64,
         }
     }
-
-    pub fn bit_width(self) -> u64 {
-        match self {
-            FloatTy::F32 => 32,
-            FloatTy::F64 => 64,
-        }
-    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
@@ -1764,29 +1749,6 @@ impl IntTy {
             IntTy::I128 => sym::i128,
         }
     }
-
-    pub fn bit_width(&self) -> Option<u64> {
-        Some(match *self {
-            IntTy::Isize => return None,
-            IntTy::I8 => 8,
-            IntTy::I16 => 16,
-            IntTy::I32 => 32,
-            IntTy::I64 => 64,
-            IntTy::I128 => 128,
-        })
-    }
-
-    pub fn normalize(&self, target_width: u32) -> Self {
-        match self {
-            IntTy::Isize => match target_width {
-                16 => IntTy::I16,
-                32 => IntTy::I32,
-                64 => IntTy::I64,
-                _ => unreachable!(),
-            },
-            _ => *self,
-        }
-    }
 }
 
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Copy, Debug)]
@@ -1822,29 +1784,6 @@ impl UintTy {
             UintTy::U128 => sym::u128,
         }
     }
-
-    pub fn bit_width(&self) -> Option<u64> {
-        Some(match *self {
-            UintTy::Usize => return None,
-            UintTy::U8 => 8,
-            UintTy::U16 => 16,
-            UintTy::U32 => 32,
-            UintTy::U64 => 64,
-            UintTy::U128 => 128,
-        })
-    }
-
-    pub fn normalize(&self, target_width: u32) -> Self {
-        match self {
-            UintTy::Usize => match target_width {
-                16 => UintTy::U16,
-                32 => UintTy::U32,
-                64 => UintTy::U64,
-                _ => unreachable!(),
-            },
-            _ => *self,
-        }
-    }
 }
 
 /// A constraint on an associated type (e.g., `A = Bar` in `Foo<A = Bar>` or
@@ -2215,9 +2154,6 @@ pub struct FnDecl {
 }
 
 impl FnDecl {
-    pub fn get_self(&self) -> Option<ExplicitSelf> {
-        self.inputs.get(0).and_then(Param::to_self)
-    }
     pub fn has_self(&self) -> bool {
         self.inputs.get(0).map_or(false, Param::is_self)
     }

compiler/rustc_ast/src/attr/mod.rs

@@ -100,16 +100,7 @@ impl NestedMetaItem {
         self.meta_item().map_or(false, |meta_item| meta_item.is_word())
     }
 
-    /// Returns `true` if `self` is a `MetaItem` and the meta item is a `ValueString`.
-    pub fn is_value_str(&self) -> bool {
-        self.value_str().is_some()
-    }
-
-    /// Returns `true` if `self` is a `MetaItem` and the meta item is a list.
-    pub fn is_meta_item_list(&self) -> bool {
-        self.meta_item_list().is_some()
-    }
-
+    /// See [`MetaItem::name_value_literal_span`].
     pub fn name_value_literal_span(&self) -> Option<Span> {
         self.meta_item()?.name_value_literal_span()
     }
@@ -165,31 +156,6 @@ impl Attribute {
             false
         }
     }
-
-    pub fn is_meta_item_list(&self) -> bool {
-        self.meta_item_list().is_some()
-    }
-
-    /// Indicates if the attribute is a `ValueString`.
-    pub fn is_value_str(&self) -> bool {
-        self.value_str().is_some()
-    }
-
-    /// This is used in case you want the value span instead of the whole attribute. Example:
-    ///
-    /// ```text
-    /// #[doc(alias = "foo")]
-    /// ```
-    ///
-    /// In here, it'll return a span for `"foo"`.
-    pub fn name_value_literal_span(&self) -> Option<Span> {
-        match self.kind {
-            AttrKind::Normal(ref item, _) => {
-                item.meta(self.span).and_then(|meta| meta.name_value_literal_span())
-            }
-            AttrKind::DocComment(..) => None,
-        }
-    }
 }
 
 impl MetaItem {
@@ -236,10 +202,6 @@ impl MetaItem {
         self.path == name
     }
 
-    pub fn is_value_str(&self) -> bool {
-        self.value_str().is_some()
-    }
-
     /// This is used in case you want the value span instead of the whole attribute. Example:
     ///
     /// ```text

compiler/rustc_ast/src/tokenstream.rs

@@ -89,10 +89,6 @@ impl TokenTree {
         }
     }
 
-    pub fn joint(self) -> TokenStream {
-        TokenStream::new(vec![(self, Spacing::Joint)])
-    }
-
     pub fn token(kind: TokenKind, span: Span) -> TokenTree {
         TokenTree::Token(Token::new(kind, span))
     }
@@ -278,14 +274,6 @@ impl TokenStream {
         self.0.len()
     }
 
-    pub fn span(&self) -> Option<Span> {
-        match &**self.0 {
-            [] => None,
-            [(tt, _)] => Some(tt.span()),
-            [(tt_start, _), .., (tt_end, _)] => Some(tt_start.span().to(tt_end.span())),
-        }
-    }
-
     pub fn from_streams(mut streams: SmallVec<[TokenStream; 2]>) -> TokenStream {
         match streams.len() {
             0 => TokenStream::default(),
@@ -325,10 +313,6 @@ impl TokenStream {
         }
     }
 
-    pub fn trees_ref(&self) -> CursorRef<'_> {
-        CursorRef::new(self)
-    }
-
     pub fn trees(&self) -> Cursor {
         self.clone().into_trees()
     }
@@ -427,10 +411,6 @@ pub struct CursorRef<'t> {
 }
 
 impl<'t> CursorRef<'t> {
-    fn new(stream: &TokenStream) -> CursorRef<'_> {
-        CursorRef { stream, index: 0 }
-    }
-
     fn next_with_spacing(&mut self) -> Option<&'t TreeAndSpacing> {
         self.stream.0.get(self.index).map(|tree| {
             self.index += 1;

compiler/rustc_ast_pretty/src/pprust/mod.rs

@@ -22,10 +22,6 @@ pub fn token_to_string(token: &Token) -> String {
     State::new().token_to_string(token)
 }
 
-pub fn token_to_string_ext(token: &Token, convert_dollar_crate: bool) -> String {
-    State::new().token_to_string_ext(token, convert_dollar_crate)
-}
-
 pub fn ty_to_string(ty: &ast::Ty) -> String {
     State::new().ty_to_string(ty)
 }
@@ -50,18 +46,10 @@ pub fn tts_to_string(tokens: &TokenStream) -> String {
     State::new().tts_to_string(tokens)
 }
 
-pub fn stmt_to_string(stmt: &ast::Stmt) -> String {
-    State::new().stmt_to_string(stmt)
-}
-
 pub fn item_to_string(i: &ast::Item) -> String {
     State::new().item_to_string(i)
 }
 
-pub fn generic_params_to_string(generic_params: &[ast::GenericParam]) -> String {
-    State::new().generic_params_to_string(generic_params)
-}
-
 pub fn path_to_string(p: &ast::Path) -> String {
     State::new().path_to_string(p)
 }
@@ -74,26 +62,14 @@ pub fn vis_to_string(v: &ast::Visibility) -> String {
     State::new().vis_to_string(v)
 }
 
-pub fn block_to_string(blk: &ast::Block) -> String {
-    State::new().block_to_string(blk)
-}
-
 pub fn meta_list_item_to_string(li: &ast::NestedMetaItem) -> String {
     State::new().meta_list_item_to_string(li)
 }
 
-pub fn attr_item_to_string(ai: &ast::AttrItem) -> String {
-    State::new().attr_item_to_string(ai)
-}
-
 pub fn attribute_to_string(attr: &ast::Attribute) -> String {
     State::new().attribute_to_string(attr)
 }
 
-pub fn param_to_string(arg: &ast::Param) -> String {
-    State::new().param_to_string(arg)
-}
-
 pub fn to_string(f: impl FnOnce(&mut State<'_>)) -> String {
     State::new().to_string(f)
 }

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -2292,10 +2292,6 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn print_usize(&mut self, i: usize) {
-        self.s.word(i.to_string())
-    }
-
     crate fn print_name(&mut self, name: Symbol) {
         self.s.word(name.to_string());
         self.ann.post(self, AnnNode::Name(&name))