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Avoid passing around an Expr that is only needed for its HirId and …
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…its Span
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@oli-obk
oli-obk committed Feb 5, 2025
1 parent d1231ea commit 9f5473f
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Showing 2 changed files with 40 additions and 31 deletions.
2 changes: 1 addition & 1 deletion compiler/rustc_lint/src/types.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -557,7 +557,7 @@ impl<'tcx> LateLintPass<'tcx> for TypeLimits {
}
}
}
hir::ExprKind::Lit(lit) => lint_literal(cx, self, e, lit),
hir::ExprKind::Lit(lit) => lint_literal(cx, self, e.hir_id, e.span, lit),
hir::ExprKind::Call(path, [l, r])
if let ExprKind::Path(ref qpath) = path.kind
&& let Some(def_id) = cx.qpath_res(qpath, path.hir_id).opt_def_id()
Expand Down
69 changes: 39 additions & 30 deletions compiler/rustc_lint/src/types/literal.rs
View file
Original file line number Diff line number Diff line change
@@ -1,8 +1,10 @@
use hir::{ExprKind, Node, is_range_literal};
use rustc_abi::{Integer, Size};
use rustc_hir::HirId;
use rustc_middle::ty::Ty;
use rustc_middle::ty::layout::IntegerExt;
use rustc_middle::{bug, ty};
use rustc_span::Span;
use {rustc_ast as ast, rustc_attr_parsing as attr, rustc_hir as hir};

use crate::LateContext;
Expand All @@ -21,21 +23,22 @@ fn lint_overflowing_range_endpoint<'tcx>(
lit: &hir::Lit,
lit_val: u128,
max: u128,
expr: &'tcx hir::Expr<'tcx>,
hir_id: HirId,
lit_span: Span,
ty: &str,
) -> bool {
// Look past casts to support cases like `0..256 as u8`
let (expr, lit_span) = if let Node::Expr(par_expr) = cx.tcx.parent_hir_node(expr.hir_id)
let (hir_id, span) = if let Node::Expr(par_expr) = cx.tcx.parent_hir_node(hir_id)
&& let ExprKind::Cast(_, _) = par_expr.kind
{
(par_expr, expr.span)
(par_expr.hir_id, par_expr.span)
} else {
(expr, expr.span)
(hir_id, lit_span)
};

// We only want to handle exclusive (`..`) ranges,
// which are represented as `ExprKind::Struct`.
let Node::ExprField(field) = cx.tcx.parent_hir_node(expr.hir_id) else { return false };
let Node::ExprField(field) = cx.tcx.parent_hir_node(hir_id) else { return false };
let Node::Expr(struct_expr) = cx.tcx.parent_hir_node(field.hir_id) else { return false };
if !is_range_literal(struct_expr) {
return false;
Expand All @@ -45,7 +48,7 @@ fn lint_overflowing_range_endpoint<'tcx>(
// We can suggest using an inclusive range
// (`..=`) instead only if it is the `end` that is
// overflowing and only by 1.
if !(end.expr.hir_id == expr.hir_id && lit_val - 1 == max) {
if !(end.expr.hir_id == hir_id && lit_val - 1 == max) {
return false;
};

Expand All @@ -57,7 +60,7 @@ fn lint_overflowing_range_endpoint<'tcx>(
_ => bug!(),
};

let sub_sugg = if expr.span.lo() == lit_span.lo() {
let sub_sugg = if span.lo() == lit_span.lo() {
let Ok(start) = cx.sess().source_map().span_to_snippet(start.span) else { return false };
UseInclusiveRange::WithoutParen {
sugg: struct_expr.span.shrink_to_lo().to(lit_span.shrink_to_hi()),
Expand All @@ -67,7 +70,7 @@ fn lint_overflowing_range_endpoint<'tcx>(
}
} else {
UseInclusiveRange::WithParen {
eq_sugg: expr.span.shrink_to_lo(),
eq_sugg: span.shrink_to_lo(),
lit_sugg: lit_span,
literal: lit_val - 1,
suffix,
Expand Down Expand Up @@ -125,7 +128,8 @@ fn get_bin_hex_repr(cx: &LateContext<'_>, lit: &hir::Lit) -> Option<String> {

fn report_bin_hex_error(
cx: &LateContext<'_>,
expr: &hir::Expr<'_>,
hir_id: HirId,
span: Span,
ty: attr::IntType,
size: Size,
repr_str: String,
Expand All @@ -144,19 +148,19 @@ fn report_bin_hex_error(
};
let sign =
if negative { OverflowingBinHexSign::Negative } else { OverflowingBinHexSign::Positive };
let sub = get_type_suggestion(cx.typeck_results().node_type(expr.hir_id), val, negative).map(
let sub = get_type_suggestion(cx.typeck_results().node_type(hir_id), val, negative).map(
|suggestion_ty| {
if let Some(pos) = repr_str.chars().position(|c| c == 'i' || c == 'u') {
let (sans_suffix, _) = repr_str.split_at(pos);
OverflowingBinHexSub::Suggestion { span: expr.span, suggestion_ty, sans_suffix }
OverflowingBinHexSub::Suggestion { span, suggestion_ty, sans_suffix }
} else {
OverflowingBinHexSub::Help { suggestion_ty }
}
},
);
let sign_bit_sub = (!negative)
.then(|| {
let ty::Int(int_ty) = cx.typeck_results().node_type(expr.hir_id).kind() else {
let ty::Int(int_ty) = cx.typeck_results().node_type(hir_id).kind() else {
return None;
};

Expand All @@ -177,7 +181,7 @@ fn report_bin_hex_error(
};

Some(OverflowingBinHexSignBitSub {
span: expr.span,
span,
lit_no_suffix,
negative_val: actually.clone(),
int_ty: int_ty.name_str(),
Expand All @@ -186,7 +190,7 @@ fn report_bin_hex_error(
})
.flatten();

cx.emit_span_lint(OVERFLOWING_LITERALS, expr.span, OverflowingBinHex {
cx.emit_span_lint(OVERFLOWING_LITERALS, span, OverflowingBinHex {
ty: t,
lit: repr_str.clone(),
dec: val,
Expand Down Expand Up @@ -236,23 +240,25 @@ fn literal_to_i128(val: u128, negative: bool) -> Option<i128> {
fn lint_int_literal<'tcx>(
cx: &LateContext<'tcx>,
type_limits: &TypeLimits,
e: &'tcx hir::Expr<'tcx>,
hir_id: HirId,
span: Span,
lit: &hir::Lit,
t: ty::IntTy,
v: u128,
) {
let int_type = t.normalize(cx.sess().target.pointer_width);
let (min, max) = int_ty_range(int_type);
let max = max as u128;
let negative = type_limits.negated_expr_id == Some(e.hir_id);
let negative = type_limits.negated_expr_id == Some(hir_id);

// Detect literal value out of range [min, max] inclusive
// avoiding use of -min to prevent overflow/panic
if (negative && v > max + 1) || (!negative && v > max) {
if let Some(repr_str) = get_bin_hex_repr(cx, lit) {
report_bin_hex_error(
cx,
e,
hir_id,
span,
attr::IntType::SignedInt(ty::ast_int_ty(t)),
Integer::from_int_ty(cx, t).size(),
repr_str,
Expand All @@ -262,18 +268,18 @@ fn lint_int_literal<'tcx>(
return;
}

if lint_overflowing_range_endpoint(cx, lit, v, max, e, t.name_str()) {
if lint_overflowing_range_endpoint(cx, lit, v, max, hir_id, span, t.name_str()) {
// The overflowing literal lint was emitted by `lint_overflowing_range_endpoint`.
return;
}

let span = if negative { type_limits.negated_expr_span.unwrap() } else { e.span };
let span = if negative { type_limits.negated_expr_span.unwrap() } else { span };
let lit = cx
.sess()
.source_map()
.span_to_snippet(span)
.unwrap_or_else(|_| if negative { format!("-{v}") } else { v.to_string() });
let help = get_type_suggestion(cx.typeck_results().node_type(e.hir_id), v, negative)
let help = get_type_suggestion(cx.typeck_results().node_type(hir_id), v, negative)
.map(|suggestion_ty| OverflowingIntHelp { suggestion_ty });

cx.emit_span_lint(OVERFLOWING_LITERALS, span, OverflowingInt {
Expand All @@ -288,7 +294,8 @@ fn lint_int_literal<'tcx>(

fn lint_uint_literal<'tcx>(
cx: &LateContext<'tcx>,
e: &'tcx hir::Expr<'tcx>,
hir_id: HirId,
span: Span,
lit: &hir::Lit,
t: ty::UintTy,
) {
Expand All @@ -302,7 +309,7 @@ fn lint_uint_literal<'tcx>(
};

if lit_val < min || lit_val > max {
if let Node::Expr(par_e) = cx.tcx.parent_hir_node(e.hir_id) {
if let Node::Expr(par_e) = cx.tcx.parent_hir_node(hir_id) {
match par_e.kind {
hir::ExprKind::Cast(..) => {
if let ty::Char = cx.typeck_results().expr_ty(par_e).kind() {
Expand All @@ -316,14 +323,15 @@ fn lint_uint_literal<'tcx>(
_ => {}
}
}
if lint_overflowing_range_endpoint(cx, lit, lit_val, max, e, t.name_str()) {
if lint_overflowing_range_endpoint(cx, lit, lit_val, max, hir_id, span, t.name_str()) {
// The overflowing literal lint was emitted by `lint_overflowing_range_endpoint`.
return;
}
if let Some(repr_str) = get_bin_hex_repr(cx, lit) {
report_bin_hex_error(
cx,
e,
hir_id,
span,
attr::IntType::UnsignedInt(ty::ast_uint_ty(t)),
Integer::from_uint_ty(cx, t).size(),
repr_str,
Expand All @@ -332,7 +340,7 @@ fn lint_uint_literal<'tcx>(
);
return;
}
cx.emit_span_lint(OVERFLOWING_LITERALS, e.span, OverflowingUInt {
cx.emit_span_lint(OVERFLOWING_LITERALS, span, OverflowingUInt {
ty: t.name_str(),
lit: cx
.sess()
Expand All @@ -348,19 +356,20 @@ fn lint_uint_literal<'tcx>(
pub(crate) fn lint_literal<'tcx>(
cx: &LateContext<'tcx>,
type_limits: &TypeLimits,
e: &'tcx hir::Expr<'tcx>,
hir_id: HirId,
span: Span,
lit: &hir::Lit,
) {
match *cx.typeck_results().node_type(e.hir_id).kind() {
match *cx.typeck_results().node_type(hir_id).kind() {
ty::Int(t) => {
match lit.node {
ast::LitKind::Int(v, ast::LitIntType::Signed(_) | ast::LitIntType::Unsuffixed) => {
lint_int_literal(cx, type_limits, e, lit, t, v.get())
lint_int_literal(cx, type_limits, hir_id, span, lit, t, v.get())
}
_ => bug!(),
};
}
ty::Uint(t) => lint_uint_literal(cx, e, lit, t),
ty::Uint(t) => lint_uint_literal(cx, hir_id, span, lit, t),
ty::Float(t) => {
let (is_infinite, sym) = match lit.node {
ast::LitKind::Float(v, _) => match t {
Expand All @@ -374,7 +383,7 @@ pub(crate) fn lint_literal<'tcx>(
_ => bug!(),
};
if is_infinite == Ok(true) {
cx.emit_span_lint(OVERFLOWING_LITERALS, e.span, OverflowingLiteral {
cx.emit_span_lint(OVERFLOWING_LITERALS, span, OverflowingLiteral {
ty: t.name_str(),
lit: cx
.sess()
Expand Down

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