rustc_const_eval: always demand typeck_tables for evaluating constants.

Author: eddyb

src/librustc/diagnostics.rs

@@ -390,44 +390,6 @@ RFC. It is, however, [currently unimplemented][iss15872].
 [iss15872]: https://github.com/rust-lang/rust/issues/15872
 "##,
 
-E0109: r##"
-You tried to give a type parameter to a type which doesn't need it. Erroneous
-code example:
-
-```compile_fail,E0109
-type X = u32<i32>; // error: type parameters are not allowed on this type
-```
-
-Please check that you used the correct type and recheck its definition. Perhaps
-it doesn't need the type parameter.
-
-Example:
-
-```
-type X = u32; // this compiles
-```
-
-Note that type parameters for enum-variant constructors go after the variant,
-not after the enum (Option::None::<u32>, not Option::<u32>::None).
-"##,
-
-E0110: r##"
-You tried to give a lifetime parameter to a type which doesn't need it.
-Erroneous code example:
-
-```compile_fail,E0110
-type X = u32<'static>; // error: lifetime parameters are not allowed on
-                       //        this type
-```
-
-Please check that the correct type was used and recheck its definition; perhaps
-it doesn't need the lifetime parameter. Example:
-
-```
-type X = u32; // ok!
-```
-"##,
-
 E0133: r##"
 Unsafe code was used outside of an unsafe function or block.
 
@@ -627,41 +589,6 @@ attributes:
 See also https://doc.rust-lang.org/book/no-stdlib.html
 "##,
 
-E0229: r##"
-An associated type binding was done outside of the type parameter declaration
-and `where` clause. Erroneous code example:
-
-```compile_fail,E0229
-pub trait Foo {
-    type A;
-    fn boo(&self) -> <Self as Foo>::A;
-}
-
-struct Bar;
-
-impl Foo for isize {
-    type A = usize;
-    fn boo(&self) -> usize { 42 }
-}
-
-fn baz<I>(x: &<I as Foo<A=Bar>>::A) {}
-// error: associated type bindings are not allowed here
-```
-
-To solve this error, please move the type bindings in the type parameter
-declaration:
-
-```ignore
-fn baz<I: Foo<A=Bar>>(x: &<I as Foo>::A) {} // ok!
-```
-
-Or in the `where` clause:
-
-```ignore
-fn baz<I>(x: &<I as Foo>::A) where I: Foo<A=Bar> {}
-```
-"##,
-
 E0261: r##"
 When using a lifetime like `'a` in a type, it must be declared before being
 used.

src/librustc/lib.rs

@@ -76,7 +76,6 @@ pub mod infer;
 pub mod lint;
 
 pub mod middle {
-    pub mod astconv_util;
     pub mod expr_use_visitor;
     pub mod const_val;
     pub mod cstore;

src/librustc/middle/astconv_util.rs

@@ -12,28 +12,30 @@ use syntax::symbol::InternedString;
 use syntax::ast;
 use std::rc::Rc;
 use hir::def_id::DefId;
+use ty::subst::Substs;
 use rustc_const_math::*;
+
 use self::ConstVal::*;
 pub use rustc_const_math::ConstInt;
 
 use std::collections::BTreeMap;
 
 #[derive(Clone, Debug, Hash, RustcEncodable, RustcDecodable, Eq, PartialEq)]
-pub enum ConstVal {
+pub enum ConstVal<'tcx> {
     Float(ConstFloat),
     Integral(ConstInt),
     Str(InternedString),
     ByteStr(Rc<Vec<u8>>),
     Bool(bool),
-    Function(DefId),
-    Struct(BTreeMap<ast::Name, ConstVal>),
-    Tuple(Vec<ConstVal>),
-    Array(Vec<ConstVal>),
-    Repeat(Box<ConstVal>, u64),
+    Function(DefId, &'tcx Substs<'tcx>),
+    Struct(BTreeMap<ast::Name, ConstVal<'tcx>>),
+    Tuple(Vec<ConstVal<'tcx>>),
+    Array(Vec<ConstVal<'tcx>>),
+    Repeat(Box<ConstVal<'tcx>>, u64),
     Char(char),
 }
 
-impl ConstVal {
+impl<'tcx> ConstVal<'tcx> {
     pub fn description(&self) -> &'static str {
         match *self {
             Float(f) => f.description(),
@@ -43,7 +45,7 @@ impl ConstVal {
             Bool(_) => "boolean",
             Struct(_) => "struct",
             Tuple(_) => "tuple",
-            Function(_) => "function definition",
+            Function(..) => "function definition",
             Array(..) => "array",
             Repeat(..) => "repeat",
             Char(..) => "char",
@@ -53,8 +55,7 @@ impl ConstVal {
     pub fn to_const_int(&self) -> Option<ConstInt> {
         match *self {
             ConstVal::Integral(i) => Some(i),
-            ConstVal::Bool(true) => Some(ConstInt::Infer(1)),
-            ConstVal::Bool(false) => Some(ConstInt::Infer(0)),
+            ConstVal::Bool(b) => Some(ConstInt::U8(b as u8)),
             ConstVal::Char(ch) => Some(ConstInt::U32(ch as u32)),
             _ => None
         }

src/librustc/middle/const_val.rs

@@ -542,7 +542,7 @@ impl<'tcx> Terminator<'tcx> {
 impl<'tcx> TerminatorKind<'tcx> {
     pub fn if_<'a, 'gcx>(tcx: ty::TyCtxt<'a, 'gcx, 'tcx>, cond: Operand<'tcx>,
                          t: BasicBlock, f: BasicBlock) -> TerminatorKind<'tcx> {
-        static BOOL_SWITCH_FALSE: &'static [ConstInt] = &[ConstInt::Infer(0)];
+        static BOOL_SWITCH_FALSE: &'static [ConstInt] = &[ConstInt::U8(0)];
         TerminatorKind::SwitchInt {
             discr: cond,
             switch_ty: tcx.types.bool,
@@ -1224,7 +1224,7 @@ pub enum Literal<'tcx> {
         substs: &'tcx Substs<'tcx>,
     },
     Value {
-        value: ConstVal,
+        value: ConstVal<'tcx>,
     },
     Promoted {
         // Index into the `promoted` vector of `Mir`.
@@ -1271,7 +1271,7 @@ fn fmt_const_val<W: Write>(fmt: &mut W, const_val: &ConstVal) -> fmt::Result {
             write!(fmt, "b\"{}\"", escaped)
         }
         Bool(b) => write!(fmt, "{:?}", b),
-        Function(def_id) => write!(fmt, "{}", item_path_str(def_id)),
+        Function(def_id, _) => write!(fmt, "{}", item_path_str(def_id)),
         Struct(_) | Tuple(_) | Array(_) | Repeat(..) =>
             bug!("ConstVal `{:?}` should not be in MIR", const_val),
         Char(c) => write!(fmt, "{:?}", c),

src/librustc/mir/mod.rs

@@ -244,6 +244,10 @@ pub struct TypeckTables<'tcx> {
     /// Set of trait imports actually used in the method resolution.
     /// This is used for warning unused imports.
     pub used_trait_imports: DefIdSet,
+
+    /// If any errors occurred while type-checking this body,
+    /// this field will be set to `true`.
+    pub tainted_by_errors: bool,
 }
 
 impl<'tcx> TypeckTables<'tcx> {
@@ -262,6 +266,7 @@ impl<'tcx> TypeckTables<'tcx> {
             cast_kinds: NodeMap(),
             lints: lint::LintTable::new(),
             used_trait_imports: DefIdSet(),
+            tainted_by_errors: false,
         }
     }
 

src/librustc/ty/context.rs

@@ -20,7 +20,6 @@ use ty::{self, Ty, TyCtxt, TypeFoldable, ReprOptions};
 use syntax::ast::{FloatTy, IntTy, UintTy};
 use syntax::attr;
 use syntax_pos::DUMMY_SP;
-use rustc_const_math::ConstInt;
 
 use std::cmp;
 use std::fmt;
@@ -1183,11 +1182,7 @@ impl<'a, 'gcx, 'tcx> Layout {
                                                             i64::min_value(),
                                                             true);
                     for discr in def.discriminants(tcx) {
-                        let x = match discr.erase_type() {
-                            ConstInt::InferSigned(i) => i as i64,
-                            ConstInt::Infer(i) => i as u64 as i64,
-                            _ => bug!()
-                        };
+                        let x = discr.to_u128_unchecked() as i64;
                         if x == 0 { non_zero = false; }
                         if x < min { min = x; }
                         if x > max { max = x; }

src/librustc/ty/layout.rs

@@ -381,7 +381,7 @@ define_maps! { <'tcx>
 
     /// Results of evaluating monomorphic constants embedded in
     /// other items, such as enum variant explicit discriminants.
-    pub monomorphic_const_eval: MonomorphicConstEval(DefId) -> Result<ConstVal, ()>
+    pub monomorphic_const_eval: MonomorphicConstEval(DefId) -> Result<ConstVal<'tcx>, ()>
 }
 
 fn coherent_trait_dep_node((_, def_id): (CrateNum, DefId)) -> DepNode<DefId> {

src/librustc/ty/maps.rs

@@ -47,6 +47,35 @@ type Disr = ConstInt;
  }
 
 
+macro_rules! typed_literal {
+    ($tcx:expr, $ty:expr, $lit:expr) => {
+        match $ty {
+            SignedInt(ast::IntTy::I8)    => ConstInt::I8($lit),
+            SignedInt(ast::IntTy::I16)   => ConstInt::I16($lit),
+            SignedInt(ast::IntTy::I32)   => ConstInt::I32($lit),
+            SignedInt(ast::IntTy::I64)   => ConstInt::I64($lit),
+            SignedInt(ast::IntTy::I128)   => ConstInt::I128($lit),
+            SignedInt(ast::IntTy::Is) => match $tcx.sess.target.int_type {
+                ast::IntTy::I16 => ConstInt::Isize(ConstIsize::Is16($lit)),
+                ast::IntTy::I32 => ConstInt::Isize(ConstIsize::Is32($lit)),
+                ast::IntTy::I64 => ConstInt::Isize(ConstIsize::Is64($lit)),
+                _ => bug!(),
+            },
+            UnsignedInt(ast::UintTy::U8)  => ConstInt::U8($lit),
+            UnsignedInt(ast::UintTy::U16) => ConstInt::U16($lit),
+            UnsignedInt(ast::UintTy::U32) => ConstInt::U32($lit),
+            UnsignedInt(ast::UintTy::U64) => ConstInt::U64($lit),
+            UnsignedInt(ast::UintTy::U128) => ConstInt::U128($lit),
+            UnsignedInt(ast::UintTy::Us) => match $tcx.sess.target.uint_type {
+                ast::UintTy::U16 => ConstInt::Usize(ConstUsize::Us16($lit)),
+                ast::UintTy::U32 => ConstInt::Usize(ConstUsize::Us32($lit)),
+                ast::UintTy::U64 => ConstInt::Usize(ConstUsize::Us64($lit)),
+                _ => bug!(),
+            },
+        }
+    }
+}
+
 impl IntTypeExt for attr::IntType {
     fn to_ty<'a, 'gcx, 'tcx>(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Ty<'tcx> {
         match *self {
@@ -66,30 +95,7 @@ impl IntTypeExt for attr::IntType {
     }
 
     fn initial_discriminant<'a, 'tcx>(&self, tcx: TyCtxt<'a, 'tcx, 'tcx>) -> Disr {
-        match *self {
-            SignedInt(ast::IntTy::I8)    => ConstInt::I8(0),
-            SignedInt(ast::IntTy::I16)   => ConstInt::I16(0),
-            SignedInt(ast::IntTy::I32)   => ConstInt::I32(0),
-            SignedInt(ast::IntTy::I64)   => ConstInt::I64(0),
-            SignedInt(ast::IntTy::I128)   => ConstInt::I128(0),
-            SignedInt(ast::IntTy::Is) => match tcx.sess.target.int_type {
-                ast::IntTy::I16 => ConstInt::Isize(ConstIsize::Is16(0)),
-                ast::IntTy::I32 => ConstInt::Isize(ConstIsize::Is32(0)),
-                ast::IntTy::I64 => ConstInt::Isize(ConstIsize::Is64(0)),
-                _ => bug!(),
-            },
-            UnsignedInt(ast::UintTy::U8)  => ConstInt::U8(0),
-            UnsignedInt(ast::UintTy::U16) => ConstInt::U16(0),
-            UnsignedInt(ast::UintTy::U32) => ConstInt::U32(0),
-            UnsignedInt(ast::UintTy::U64) => ConstInt::U64(0),
-            UnsignedInt(ast::UintTy::U128) => ConstInt::U128(0),
-            UnsignedInt(ast::UintTy::Us) => match tcx.sess.target.uint_type {
-                ast::UintTy::U16 => ConstInt::Usize(ConstUsize::Us16(0)),
-                ast::UintTy::U32 => ConstInt::Usize(ConstUsize::Us32(0)),
-                ast::UintTy::U64 => ConstInt::Usize(ConstUsize::Us64(0)),
-                _ => bug!(),
-            },
-        }
+        typed_literal!(tcx, *self, 0)
     }
 
     fn assert_ty_matches(&self, val: Disr) {
@@ -114,7 +120,7 @@ impl IntTypeExt for attr::IntType {
                            -> Option<Disr> {
         if let Some(val) = val {
             self.assert_ty_matches(val);
-            (val + ConstInt::Infer(1)).ok()
+            (val + typed_literal!(tcx, *self, 1)).ok()
         } else {
             Some(self.initial_discriminant(tcx))
         }