Rollup merge of #67426 - Centril:rollup-rswp4rf, r=Centril

Rollup of 7 pull requests

Successful merges:

 - #66670 (Normalize ident)
 - #66755 (Remove a const-if-hack in RawVec)
 - #67127 (Use structured suggestion for disambiguating method calls)
 - #67281 (add string.insert benchmarks)
 - #67328 (Remove now-redundant range check on u128 -> f32 casts)
 - #67392 (Fix unresolved type span inside async object)
 - #67421 (Fix internal documentation typo)

Failed merges:

r? @ghost

Author: Centril

Cargo.lock

@@ -3770,6 +3770,7 @@ dependencies = [
  "smallvec 1.0.0",
  "syntax",
  "syntax_pos",
+ "unicode-normalization",
 ]
 
 [[package]]
@@ -4976,9 +4977,12 @@ dependencies = [
 
 [[package]]
 name = "unicode-normalization"
-version = "0.1.7"
+version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a0180bc61fc5a987082bfa111f4cc95c4caff7f9799f3e46df09163a937aa25"
+checksum = "b561e267b2326bb4cebfc0ef9e68355c7abe6c6f522aeac2f5bf95d56c59bdcf"
+dependencies = [
+ "smallvec 1.0.0",
+]
 
 [[package]]
 name = "unicode-segmentation"

src/liballoc/benches/string.rs

@@ -122,3 +122,43 @@ fn bench_to_string(b: &mut Bencher) {
              Lorem ipsum dolor sit amet, consectetur. ";
     b.iter(|| s.to_string())
 }
+
+#[bench]
+fn bench_insert_char_short(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert(6, black_box(' '));
+        x
+    })
+}
+
+#[bench]
+fn bench_insert_char_long(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert(6, black_box('❤'));
+        x
+    })
+}
+
+#[bench]
+fn bench_insert_str_short(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert_str(6, black_box(" "));
+        x
+    })
+}
+
+#[bench]
+fn bench_insert_str_long(b: &mut Bencher) {
+    let s = "Hello, World!";
+    b.iter(|| {
+        let mut x = String::from(s);
+        black_box(&mut x).insert_str(6, black_box(" rustic "));
+        x
+    })
+}

src/liballoc/lib.rs

@@ -85,6 +85,7 @@
 #![feature(const_generic_impls_guard)]
 #![feature(const_generics)]
 #![feature(const_in_array_repeat_expressions)]
+#![feature(const_if_match)]
 #![feature(cow_is_borrowed)]
 #![feature(dispatch_from_dyn)]
 #![feature(core_intrinsics)]

src/liballoc/raw_vec.rs

@@ -52,15 +52,12 @@ impl<T, A: Alloc> RawVec<T, A> {
     /// Like `new`, but parameterized over the choice of allocator for
     /// the returned `RawVec`.
     pub const fn new_in(a: A) -> Self {
-        // `!0` is `usize::MAX`. This branch should be stripped at compile time.
-        // FIXME(mark-i-m): use this line when `if`s are allowed in `const`:
-        //let cap = if mem::size_of::<T>() == 0 { !0 } else { 0 };
+        let cap = if mem::size_of::<T>() == 0 { core::usize::MAX } else { 0 };
 
         // `Unique::empty()` doubles as "unallocated" and "zero-sized allocation".
         RawVec {
             ptr: Unique::empty(),
-            // FIXME(mark-i-m): use `cap` when ifs are allowed in const
-            cap: [0, !0][(mem::size_of::<T>() == 0) as usize],
+            cap,
             a,
         }
     }
@@ -132,19 +129,7 @@ impl<T> RawVec<T, Global> {
     /// `RawVec` with capacity `usize::MAX`. Useful for implementing
     /// delayed allocation.
     pub const fn new() -> Self {
-        // FIXME(Centril): Reintegrate this with `fn new_in` when we can.
-
-        // `!0` is `usize::MAX`. This branch should be stripped at compile time.
-        // FIXME(mark-i-m): use this line when `if`s are allowed in `const`:
-        //let cap = if mem::size_of::<T>() == 0 { !0 } else { 0 };
-
-        // `Unique::empty()` doubles as "unallocated" and "zero-sized allocation".
-        RawVec {
-            ptr: Unique::empty(),
-            // FIXME(mark-i-m): use `cap` when ifs are allowed in const
-            cap: [0, !0][(mem::size_of::<T>() == 0) as usize],
-            a: Global,
-        }
+        Self::new_in(Global)
     }
 
     /// Creates a `RawVec` (on the system heap) with exactly the

src/librustc/hir/mod.rs

@@ -1857,6 +1857,16 @@ impl fmt::Display for YieldSource {
     }
 }
 
+impl From<GeneratorKind> for YieldSource {
+    fn from(kind: GeneratorKind) -> Self {
+        match kind {
+            // Guess based on the kind of the current generator.
+            GeneratorKind::Gen => Self::Yield,
+            GeneratorKind::Async(_) => Self::Await,
+        }
+    }
+}
+
 // N.B., if you change this, you'll probably want to change the corresponding
 // type structure in middle/ty.rs as well.
 #[derive(RustcEncodable, RustcDecodable, Debug, HashStable)]

src/librustc/ty/mod.rs

@@ -212,6 +212,17 @@ pub enum AssocKind {
     Type
 }
 
+impl AssocKind {
+    pub fn suggestion_descr(&self) -> &'static str {
+        match self {
+            ty::AssocKind::Method => "method call",
+            ty::AssocKind::Type |
+            ty::AssocKind::OpaqueTy => "associated type",
+            ty::AssocKind::Const => "associated constant",
+        }
+    }
+}
+
 impl AssocItem {
     pub fn def_kind(&self) -> DefKind {
         match self.kind {

src/librustc_codegen_ssa/mir/rvalue.rs

@@ -341,6 +341,13 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                                     llval
                                 }
                             }
+                            (CastTy::Int(_), CastTy::Float) => {
+                                if signed {
+                                    bx.sitofp(llval, ll_t_out)
+                                } else {
+                                    bx.uitofp(llval, ll_t_out)
+                                }
+                            }
                             (CastTy::Ptr(_), CastTy::Ptr(_)) |
                             (CastTy::FnPtr, CastTy::Ptr(_)) |
                             (CastTy::RPtr(_), CastTy::Ptr(_)) =>
@@ -352,8 +359,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                                 let usize_llval = bx.intcast(llval, bx.cx().type_isize(), signed);
                                 bx.inttoptr(usize_llval, ll_t_out)
                             }
-                            (CastTy::Int(_), CastTy::Float) =>
-                                cast_int_to_float(&mut bx, signed, llval, ll_t_in, ll_t_out),
                             (CastTy::Float, CastTy::Int(IntTy::I)) =>
                                 cast_float_to_int(&mut bx, true, llval, ll_t_in, ll_t_out),
                             (CastTy::Float, CastTy::Int(_)) =>
@@ -720,40 +725,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     }
 }
 
-fn cast_int_to_float<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
-    bx: &mut Bx,
-    signed: bool,
-    x: Bx::Value,
-    int_ty: Bx::Type,
-    float_ty: Bx::Type
-) -> Bx::Value {
-    // Most integer types, even i128, fit into [-f32::MAX, f32::MAX] after rounding.
-    // It's only u128 -> f32 that can cause overflows (i.e., should yield infinity).
-    // LLVM's uitofp produces undef in those cases, so we manually check for that case.
-    let is_u128_to_f32 = !signed &&
-        bx.cx().int_width(int_ty) == 128 &&
-        bx.cx().float_width(float_ty) == 32;
-    if is_u128_to_f32 {
-        // All inputs greater or equal to (f32::MAX + 0.5 ULP) are rounded to infinity,
-        // and for everything else LLVM's uitofp works just fine.
-        use rustc_apfloat::ieee::Single;
-        const MAX_F32_PLUS_HALF_ULP: u128 = ((1 << (Single::PRECISION + 1)) - 1)
-                                            << (Single::MAX_EXP - Single::PRECISION as i16);
-        let max = bx.cx().const_uint_big(int_ty, MAX_F32_PLUS_HALF_ULP);
-        let overflow = bx.icmp(IntPredicate::IntUGE, x, max);
-        let infinity_bits = bx.cx().const_u32(ieee::Single::INFINITY.to_bits() as u32);
-        let infinity = bx.bitcast(infinity_bits, float_ty);
-        let fp = bx.uitofp(x, float_ty);
-        bx.select(overflow, infinity, fp)
-    } else {
-        if signed {
-            bx.sitofp(x, float_ty)
-        } else {
-            bx.uitofp(x, float_ty)
-        }
-    }
-}
-
 fn cast_float_to_int<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     bx: &mut Bx,
     signed: bool,

src/librustc_interface/interface.rs

@@ -25,7 +25,7 @@ use syntax_pos::edition;
 pub type Result<T> = result::Result<T, ErrorReported>;
 
 /// Represents a compiler session.
-/// Can be used run `rustc_interface` queries.
+/// Can be used to run `rustc_interface` queries.
 /// Created by passing `Config` to `run_compiler`.
 pub struct Compiler {
     pub(crate) sess: Lrc<Session>,

src/librustc_parse/Cargo.toml

@@ -20,3 +20,4 @@ rustc_error_codes = { path = "../librustc_error_codes" }
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }
 syntax_pos = { path = "../libsyntax_pos" }
 syntax = { path = "../libsyntax" }
+unicode-normalization = "0.1.11"

src/librustc_parse/lexer/mod.rs

@@ -219,8 +219,7 @@ impl<'a> StringReader<'a> {
                 if is_raw_ident {
                     ident_start = ident_start + BytePos(2);
                 }
-                // FIXME: perform NFKC normalization here. (Issue #2253)
-                let sym = self.symbol_from(ident_start);
+                let sym = self.nfc_symbol_from(ident_start);
                 if is_raw_ident {
                     let span = self.mk_sp(start, self.pos);
                     if !sym.can_be_raw() {
@@ -465,6 +464,20 @@ impl<'a> StringReader<'a> {
         Symbol::intern(self.str_from_to(start, end))
     }
 
+    /// As symbol_from, with the text normalized into Unicode NFC form.
+    fn nfc_symbol_from(&self, start: BytePos) -> Symbol {
+        use unicode_normalization::{is_nfc_quick, IsNormalized, UnicodeNormalization};
+        debug!("taking an normalized ident from {:?} to {:?}", start, self.pos);
+        let sym = self.str_from(start);
+        match is_nfc_quick(sym.chars()) {
+            IsNormalized::Yes => Symbol::intern(sym),
+            _ => {
+                let sym_str: String = sym.chars().nfc().collect();
+                Symbol::intern(&sym_str)
+            }
+        }
+    }
+
     /// Slice of the source text spanning from `start` up to but excluding `end`.
     fn str_from_to(&self, start: BytePos, end: BytePos) -> &str
     {

src/librustc_typeck/check/expr.rs

@@ -1425,8 +1425,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         field: ast::Ident,
     ) -> Ty<'tcx> {
         let expr_t = self.check_expr_with_needs(base, needs);
-        let expr_t = self.structurally_resolved_type(base.span,
-                                                     expr_t);
+        let expr_t = self.structurally_resolved_type(base.span, expr_t);
         let mut private_candidate = None;
         let mut autoderef = self.autoderef(expr.span, expr_t);
         while let Some((base_t, _)) = autoderef.next() {

src/librustc_typeck/check/generator_interior.rs

@@ -19,6 +19,7 @@ struct InteriorVisitor<'a, 'tcx> {
     region_scope_tree: &'tcx region::ScopeTree,
     expr_count: usize,
     kind: hir::GeneratorKind,
+    prev_unresolved_span: Option<Span>,
 }
 
 impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
@@ -32,7 +33,6 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
         debug!("generator_interior: attempting to record type {:?} {:?} {:?} {:?}",
                ty, scope, expr, source_span);
 
-
         let live_across_yield = scope.map(|s| {
             self.region_scope_tree.yield_in_scope(s).and_then(|yield_data| {
                 // If we are recording an expression that is the last yield
@@ -54,15 +54,11 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
         }).unwrap_or_else(|| Some(YieldData {
             span: DUMMY_SP,
             expr_and_pat_count: 0,
-            source: match self.kind { // Guess based on the kind of the current generator.
-                hir::GeneratorKind::Gen => hir::YieldSource::Yield,
-                hir::GeneratorKind::Async(_) => hir::YieldSource::Await,
-            },
+            source: self.kind.into(),
         }));
 
         if let Some(yield_data) = live_across_yield {
             let ty = self.fcx.resolve_vars_if_possible(&ty);
-
             debug!("type in expr = {:?}, scope = {:?}, type = {:?}, count = {}, yield_span = {:?}",
                    expr, scope, ty, self.expr_count, yield_data.span);
 
@@ -74,9 +70,12 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
                                    yield_data.source);
 
                 // If unresolved type isn't a ty_var then unresolved_type_span is None
+                let span = self.prev_unresolved_span.unwrap_or_else(
+                    || unresolved_type_span.unwrap_or(source_span)
+                );
                 self.fcx.need_type_info_err_in_generator(
                     self.kind,
-                    unresolved_type_span.unwrap_or(source_span),
+                    span,
                     unresolved_type,
                 )
                     .span_note(yield_data.span, &*note)
@@ -94,6 +93,13 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> {
         } else {
             debug!("no type in expr = {:?}, count = {:?}, span = {:?}",
                    expr, self.expr_count, expr.map(|e| e.span));
+            let ty = self.fcx.resolve_vars_if_possible(&ty);
+            if let Some((unresolved_type, unresolved_type_span))
+                = self.fcx.unresolved_type_vars(&ty) {
+                debug!("remained unresolved_type = {:?}, unresolved_type_span: {:?}",
+                    unresolved_type, unresolved_type_span);
+                self.prev_unresolved_span = unresolved_type_span;
+            }
         }
     }
 }
@@ -112,6 +118,7 @@ pub fn resolve_interior<'a, 'tcx>(
         region_scope_tree: fcx.tcx.region_scope_tree(def_id),
         expr_count: 0,
         kind,
+        prev_unresolved_span: None,
     };
     intravisit::walk_body(&mut visitor, body);