Fix ICE #4579

.travis.yml

@@ -62,8 +62,8 @@ matrix:
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=rust-lang/rustfmt
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
-    - env: INTEGRATION=hyperium/hyper
-      if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
+    # - env: INTEGRATION=hyperium/hyper
+    #   if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=bluss/rust-itertools
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=serde-rs/serde
@@ -72,8 +72,8 @@ matrix:
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=rust-random/rand
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
-    - env: INTEGRATION=rust-lang-nursery/futures-rs
-      if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
+    # - env: INTEGRATION=rust-lang-nursery/futures-rs
+    #   if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=Marwes/combine
       if: repo =~ /^rust-lang\/rust-clippy$/ AND branch IN (auto, try)
     - env: INTEGRATION=rust-lang-nursery/failure

clippy_lints/src/consts.rs

@@ -152,7 +152,7 @@ impl Constant {
 }
 
 /// Parses a `LitKind` to a `Constant`.
-pub fn lit_to_constant(lit: &LitKind, ty: Ty<'_>) -> Constant {
+pub fn lit_to_constant(lit: &LitKind, ty: Option<Ty<'_>>) -> Constant {
     use syntax::ast::*;
 
     match *lit {
@@ -161,7 +161,9 @@ pub fn lit_to_constant(lit: &LitKind, ty: Ty<'_>) -> Constant {
         LitKind::ByteStr(ref s) => Constant::Binary(Lrc::clone(s)),
         LitKind::Char(c) => Constant::Char(c),
         LitKind::Int(n, _) => Constant::Int(n),
-        LitKind::Float(ref is, _) | LitKind::FloatUnsuffixed(ref is) => match ty.kind {
+        LitKind::Float(ref is, FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()),
+        LitKind::Float(ref is, FloatTy::F64) => Constant::F64(is.as_str().parse().unwrap()),
+        LitKind::FloatUnsuffixed(ref is) => match ty.expect("type of float is known").kind {
             ty::Float(FloatTy::F32) => Constant::F32(is.as_str().parse().unwrap()),
             ty::Float(FloatTy::F64) => Constant::F64(is.as_str().parse().unwrap()),
             _ => bug!(),
@@ -225,7 +227,7 @@ impl<'c, 'cc> ConstEvalLateContext<'c, 'cc> {
         match e.kind {
             ExprKind::Path(ref qpath) => self.fetch_path(qpath, e.hir_id),
             ExprKind::Block(ref block, _) => self.block(block),
-            ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty(e))),
+            ExprKind::Lit(ref lit) => Some(lit_to_constant(&lit.node, self.tables.expr_ty_opt(e))),
             ExprKind::Array(ref vec) => self.multi(vec).map(Constant::Vec),
             ExprKind::Tup(ref tup) => self.multi(tup).map(Constant::Tuple),
             ExprKind::Repeat(ref value, _) => {

clippy_lints/src/neg_multiply.rs

@@ -44,7 +44,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NegMultiply {
 fn check_mul(cx: &LateContext<'_, '_>, span: Span, lit: &Expr, exp: &Expr) {
     if_chain! {
         if let ExprKind::Lit(ref l) = lit.kind;
-        if let Constant::Int(1) = consts::lit_to_constant(&l.node, cx.tables.expr_ty(lit));
+        if let Constant::Int(1) = consts::lit_to_constant(&l.node, cx.tables.expr_ty_opt(lit));
         if cx.tables.expr_ty(exp).is_integral();
         then {
             span_lint(cx, NEG_MULTIPLY, span, "Negation by multiplying with -1");

tests/ui/ice-4579.rs

@@ -0,0 +1,13 @@
+#![allow(clippy::single_match)]
+
+use std::ptr;
+
+fn main() {
+    match Some(0_usize) {
+        Some(_) => {
+            let s = "012345";
+            unsafe { ptr::read(s.as_ptr().offset(1) as *const [u8; 5]) };
+        },
+        _ => (),
+    };
+}