use rustc_errors::Applicability;
use rustc_target::spec::abi::Abi;
use rustc_typeck::hir_ty_to_ty;
-use syntax::ast::{FloatTy, IntTy, UintTy};
+use syntax::ast::{FloatTy, IntTy, LitIntType, LitKind, UintTy};
use syntax::errors::DiagnosticBuilder;
use syntax::source_map::Span;
-use syntax::symbol::sym;
+use syntax::symbol::{sym, Symbol};
use crate::consts::{constant, Constant};
use crate::utils::paths;
use crate::utils::{
clip, comparisons, differing_macro_contexts, higher, in_constant, int_bits, last_path_segment, match_def_path,
- match_path, multispan_sugg, same_tys, sext, snippet, snippet_opt, snippet_with_applicability,
+ match_path, multispan_sugg, qpath_res, same_tys, sext, snippet, snippet_opt, snippet_with_applicability,
snippet_with_macro_callsite, span_help_and_lint, span_lint, span_lint_and_sugg, span_lint_and_then, unsext,
};
_ => None,
});
if let TyKind::Path(ref qpath) = ty.node;
- if let Some(did) = cx.tables.qpath_res(qpath, ty.hir_id).opt_def_id();
+ if let Some(did) = qpath_res(cx, qpath, ty.hir_id).opt_def_id();
if match_def_path(cx, did, path);
then {
return true;
match hir_ty.node {
TyKind::Path(ref qpath) if !is_local => {
let hir_id = hir_ty.hir_id;
- let res = cx.tables.qpath_res(qpath, hir_id);
+ let res = qpath_res(cx, qpath, hir_id);
if let Some(def_id) = res.opt_def_id() {
if Some(def_id) == cx.tcx.lang_items().owned_box() {
if match_type_parameter(cx, qpath, &paths::VEC) {
);
return; // don't recurse into the type
}
- } else if match_def_path(cx, def_id, &paths::VEC) {
+ } else if cx.tcx.is_diagnostic_item(Symbol::intern("vec_type"), def_id) {
if_chain! {
// Get the _ part of Vec<_>
if let Some(ref last) = last_path_segment(qpath).args;
});
// ty is now _ at this point
if let TyKind::Path(ref ty_qpath) = ty.node;
- let res = cx.tables.qpath_res(ty_qpath, ty.hir_id);
+ let res = qpath_res(cx, ty_qpath, ty.hir_id);
if let Some(def_id) = res.opt_def_id();
if Some(def_id) == cx.tcx.lang_items().owned_box();
// At this point, we know ty is Box<T>, now get T
match mut_ty.ty.node {
TyKind::Path(ref qpath) => {
let hir_id = mut_ty.ty.hir_id;
- let def = cx.tables.qpath_res(qpath, hir_id);
+ let def = qpath_res(cx, qpath, hir_id);
if_chain! {
if let Some(def_id) = def.opt_def_id();
if Some(def_id) == cx.tcx.lang_items().owned_box();
/// }
/// ```
pub CAST_LOSSLESS,
- complexity,
+ pedantic,
"casts using `as` that are known to be lossless, e.g., `x as u64` where `x: u8`"
}
let (cast_from, cast_to) = (cx.tables.expr_ty(ex), cx.tables.expr_ty(expr));
lint_fn_to_numeric_cast(cx, expr, ex, cast_from, cast_to);
if let ExprKind::Lit(ref lit) = ex.node {
- use syntax::ast::{LitIntType, LitKind};
if let LitKind::Int(n, _) = lit.node {
if cast_to.is_floating_point() {
let from_nbits = 128 - n.leading_zeros();
/// ```
pub CHAR_LIT_AS_U8,
complexity,
- "casting a character literal to u8"
+ "casting a character literal to u8 truncates"
}
declare_lint_pass!(CharLitAsU8 => [CHAR_LIT_AS_U8]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CharLitAsU8 {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
- use syntax::ast::LitKind;
-
- if let ExprKind::Cast(ref e, _) = expr.node {
- if let ExprKind::Lit(ref l) = e.node {
- if let LitKind::Char(_) = l.node {
- if ty::Uint(UintTy::U8) == cx.tables.expr_ty(expr).sty && !expr.span.from_expansion() {
- let msg = "casting character literal to u8. `char`s \
- are 4 bytes wide in rust, so casting to u8 \
- truncates them";
- let help = format!(
- "Consider using a byte literal instead:\nb{}",
- snippet(cx, e.span, "'x'")
- );
- span_help_and_lint(cx, CHAR_LIT_AS_U8, expr.span, msg, &help);
- }
- }
+ if_chain! {
+ if !expr.span.from_expansion();
+ if let ExprKind::Cast(e, _) = &expr.node;
+ if let ExprKind::Lit(l) = &e.node;
+ if let LitKind::Char(c) = l.node;
+ if ty::Uint(UintTy::U8) == cx.tables.expr_ty(expr).sty;
+ then {
+ let mut applicability = Applicability::MachineApplicable;
+ let snippet = snippet_with_applicability(cx, e.span, "'x'", &mut applicability);
+
+ span_lint_and_then(
+ cx,
+ CHAR_LIT_AS_U8,
+ expr.span,
+ "casting a character literal to `u8` truncates",
+ |db| {
+ db.note("`char` is four bytes wide, but `u8` is a single byte");
+
+ if c.is_ascii() {
+ db.span_suggestion(
+ expr.span,
+ "use a byte literal instead",
+ format!("b{}", snippet),
+ applicability,
+ );
+ }
+ });
}
}
}