diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs index 5668d8992c8dc..7bd2507d1ade6 100644 --- a/compiler/rustc_abi/src/lib.rs +++ b/compiler/rustc_abi/src/lib.rs @@ -833,6 +833,28 @@ pub enum Integer { } impl Integer { + pub fn int_ty_str(self) -> &'static str { + use Integer::*; + match self { + I8 => "i8", + I16 => "i16", + I32 => "i32", + I64 => "i64", + I128 => "i128", + } + } + + pub fn uint_ty_str(self) -> &'static str { + use Integer::*; + match self { + I8 => "u8", + I16 => "u16", + I32 => "u32", + I64 => "u64", + I128 => "u128", + } + } + #[inline] pub fn size(self) -> Size { use Integer::*; diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs index 900c496e0330d..403e94c43384c 100644 --- a/compiler/rustc_lint/src/types.rs +++ b/compiler/rustc_lint/src/types.rs @@ -3,9 +3,9 @@ use std::ops::ControlFlow; use rustc_data_structures::fx::FxHashSet; use rustc_errors::DiagMessage; -use rustc_hir::{is_range_literal, Expr, ExprKind, Node}; +use rustc_hir::{Expr, ExprKind}; use rustc_middle::bug; -use rustc_middle::ty::layout::{IntegerExt, LayoutOf, SizeSkeleton}; +use rustc_middle::ty::layout::{LayoutOf, SizeSkeleton}; use rustc_middle::ty::{ self, AdtKind, GenericArgsRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, }; @@ -13,22 +13,23 @@ use rustc_session::{declare_lint, declare_lint_pass, impl_lint_pass}; use rustc_span::def_id::LocalDefId; use rustc_span::symbol::sym; use rustc_span::{source_map, Span, Symbol}; -use rustc_target::abi::{Abi, Integer, Size, TagEncoding, Variants, WrappingRange}; +use rustc_target::abi::{Abi, TagEncoding, Variants, WrappingRange}; use rustc_target::spec::abi::Abi as SpecAbi; use tracing::debug; -use {rustc_ast as ast, rustc_attr as attr, rustc_hir as hir}; +use {rustc_ast as ast, rustc_hir as hir}; use crate::lints::{ AmbiguousWidePointerComparisons, AmbiguousWidePointerComparisonsAddrMetadataSuggestion, AmbiguousWidePointerComparisonsAddrSuggestion, AtomicOrderingFence, AtomicOrderingLoad, AtomicOrderingStore, ImproperCTypes, InvalidAtomicOrderingDiag, InvalidNanComparisons, - InvalidNanComparisonsSuggestion, OnlyCastu8ToChar, OverflowingBinHex, OverflowingBinHexSign, - OverflowingBinHexSignBitSub, OverflowingBinHexSub, OverflowingInt, OverflowingIntHelp, - OverflowingLiteral, OverflowingUInt, RangeEndpointOutOfRange, UnusedComparisons, - UseInclusiveRange, VariantSizeDifferencesDiag, + InvalidNanComparisonsSuggestion, UnusedComparisons, VariantSizeDifferencesDiag, }; use crate::{fluent_generated as fluent, LateContext, LateLintPass, LintContext}; +mod literal; + +use literal::{int_ty_range, lint_literal, uint_ty_range}; + declare_lint! { /// The `unused_comparisons` lint detects comparisons made useless by /// limits of the types involved. @@ -185,403 +186,6 @@ impl TypeLimits { } } -/// Attempts to special-case the overflowing literal lint when it occurs as a range endpoint (`expr..MAX+1`). -/// Returns `true` iff the lint was emitted. -fn lint_overflowing_range_endpoint<'tcx>( - cx: &LateContext<'tcx>, - lit: &hir::Lit, - lit_val: u128, - max: u128, - expr: &'tcx hir::Expr<'tcx>, - 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 ExprKind::Cast(_, _) = par_expr.kind - { - (par_expr, expr.span) - } else { - (expr, expr.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::Expr(struct_expr) = cx.tcx.parent_hir_node(field.hir_id) else { return false }; - if !is_range_literal(struct_expr) { - return false; - }; - let ExprKind::Struct(_, [start, end], _) = &struct_expr.kind else { return false }; - - // 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) { - return false; - }; - - use rustc_ast::{LitIntType, LitKind}; - let suffix = match lit.node { - LitKind::Int(_, LitIntType::Signed(s)) => s.name_str(), - LitKind::Int(_, LitIntType::Unsigned(s)) => s.name_str(), - LitKind::Int(_, LitIntType::Unsuffixed) => "", - _ => bug!(), - }; - - let sub_sugg = if expr.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()), - start, - literal: lit_val - 1, - suffix, - } - } else { - UseInclusiveRange::WithParen { - eq_sugg: expr.span.shrink_to_lo(), - lit_sugg: lit_span, - literal: lit_val - 1, - suffix, - } - }; - - cx.emit_span_lint( - OVERFLOWING_LITERALS, - struct_expr.span, - RangeEndpointOutOfRange { ty, sub: sub_sugg }, - ); - - // We've just emitted a lint, special cased for `(...)..MAX+1` ranges, - // return `true` so the callers don't also emit a lint - true -} - -// For `isize` & `usize`, be conservative with the warnings, so that the -// warnings are consistent between 32- and 64-bit platforms. -fn int_ty_range(int_ty: ty::IntTy) -> (i128, i128) { - match int_ty { - ty::IntTy::Isize => (i64::MIN.into(), i64::MAX.into()), - ty::IntTy::I8 => (i8::MIN.into(), i8::MAX.into()), - ty::IntTy::I16 => (i16::MIN.into(), i16::MAX.into()), - ty::IntTy::I32 => (i32::MIN.into(), i32::MAX.into()), - ty::IntTy::I64 => (i64::MIN.into(), i64::MAX.into()), - ty::IntTy::I128 => (i128::MIN, i128::MAX), - } -} - -fn uint_ty_range(uint_ty: ty::UintTy) -> (u128, u128) { - let max = match uint_ty { - ty::UintTy::Usize => u64::MAX.into(), - ty::UintTy::U8 => u8::MAX.into(), - ty::UintTy::U16 => u16::MAX.into(), - ty::UintTy::U32 => u32::MAX.into(), - ty::UintTy::U64 => u64::MAX.into(), - ty::UintTy::U128 => u128::MAX, - }; - (0, max) -} - -fn get_bin_hex_repr(cx: &LateContext<'_>, lit: &hir::Lit) -> Option { - let src = cx.sess().source_map().span_to_snippet(lit.span).ok()?; - let firstch = src.chars().next()?; - - if firstch == '0' { - match src.chars().nth(1) { - Some('x' | 'b') => return Some(src), - _ => return None, - } - } - - None -} - -fn report_bin_hex_error( - cx: &LateContext<'_>, - expr: &hir::Expr<'_>, - ty: attr::IntType, - size: Size, - repr_str: String, - val: u128, - negative: bool, -) { - let (t, actually) = match ty { - attr::IntType::SignedInt(t) => { - let actually = if negative { -(size.sign_extend(val)) } else { size.sign_extend(val) }; - (t.name_str(), actually.to_string()) - } - attr::IntType::UnsignedInt(t) => { - let actually = size.truncate(val); - (t.name_str(), actually.to_string()) - } - }; - 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( - |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 } - } 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 { - return None; - }; - - let Some(bit_width) = int_ty.bit_width() else { - return None; // isize case - }; - - // Skip if sign bit is not set - if (val & (1 << (bit_width - 1))) == 0 { - return None; - } - - let lit_no_suffix = - if let Some(pos) = repr_str.chars().position(|c| c == 'i' || c == 'u') { - repr_str.split_at(pos).0 - } else { - &repr_str - }; - - Some(OverflowingBinHexSignBitSub { - span: expr.span, - lit_no_suffix, - negative_val: actually.clone(), - int_ty: int_ty.name_str(), - uint_ty: int_ty.to_unsigned().name_str(), - }) - }) - .flatten(); - - cx.emit_span_lint( - OVERFLOWING_LITERALS, - expr.span, - OverflowingBinHex { - ty: t, - lit: repr_str.clone(), - dec: val, - actually, - sign, - sub, - sign_bit_sub, - }, - ) -} - -// This function finds the next fitting type and generates a suggestion string. -// It searches for fitting types in the following way (`X < Y`): -// - `iX`: if literal fits in `uX` => `uX`, else => `iY` -// - `-iX` => `iY` -// - `uX` => `uY` -// -// No suggestion for: `isize`, `usize`. -fn get_type_suggestion(t: Ty<'_>, val: u128, negative: bool) -> Option<&'static str> { - use ty::IntTy::*; - use ty::UintTy::*; - macro_rules! find_fit { - ($ty:expr, $val:expr, $negative:expr, - $($type:ident => [$($utypes:expr),*] => [$($itypes:expr),*]),+) => { - { - let _neg = if negative { 1 } else { 0 }; - match $ty { - $($type => { - $(if !negative && val <= uint_ty_range($utypes).1 { - return Some($utypes.name_str()) - })* - $(if val <= int_ty_range($itypes).1 as u128 + _neg { - return Some($itypes.name_str()) - })* - None - },)+ - _ => None - } - } - } - } - match t.kind() { - ty::Int(i) => find_fit!(i, val, negative, - I8 => [U8] => [I16, I32, I64, I128], - I16 => [U16] => [I32, I64, I128], - I32 => [U32] => [I64, I128], - I64 => [U64] => [I128], - I128 => [U128] => []), - ty::Uint(u) => find_fit!(u, val, negative, - U8 => [U8, U16, U32, U64, U128] => [], - U16 => [U16, U32, U64, U128] => [], - U32 => [U32, U64, U128] => [], - U64 => [U64, U128] => [], - U128 => [U128] => []), - _ => None, - } -} - -fn lint_int_literal<'tcx>( - cx: &LateContext<'tcx>, - type_limits: &TypeLimits, - e: &'tcx hir::Expr<'tcx>, - 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); - - // 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, - attr::IntType::SignedInt(ty::ast_int_ty(t)), - Integer::from_int_ty(cx, t).size(), - repr_str, - v, - negative, - ); - return; - } - - if lint_overflowing_range_endpoint(cx, lit, v, max, e, 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 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) - .map(|suggestion_ty| OverflowingIntHelp { suggestion_ty }); - - cx.emit_span_lint( - OVERFLOWING_LITERALS, - span, - OverflowingInt { ty: t.name_str(), lit, min, max, help }, - ); - } -} - -fn lint_uint_literal<'tcx>( - cx: &LateContext<'tcx>, - e: &'tcx hir::Expr<'tcx>, - lit: &hir::Lit, - t: ty::UintTy, -) { - let uint_type = t.normalize(cx.sess().target.pointer_width); - let (min, max) = uint_ty_range(uint_type); - let lit_val: u128 = match lit.node { - // _v is u8, within range by definition - ast::LitKind::Byte(_v) => return, - ast::LitKind::Int(v, _) => v.get(), - _ => bug!(), - }; - - if lit_val < min || lit_val > max { - if let Node::Expr(par_e) = cx.tcx.parent_hir_node(e.hir_id) { - match par_e.kind { - hir::ExprKind::Cast(..) => { - if let ty::Char = cx.typeck_results().expr_ty(par_e).kind() { - cx.emit_span_lint( - OVERFLOWING_LITERALS, - par_e.span, - OnlyCastu8ToChar { span: par_e.span, literal: lit_val }, - ); - return; - } - } - _ => {} - } - } - if lint_overflowing_range_endpoint(cx, lit, lit_val, max, e, 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, - attr::IntType::UnsignedInt(ty::ast_uint_ty(t)), - Integer::from_uint_ty(cx, t).size(), - repr_str, - lit_val, - false, - ); - return; - } - cx.emit_span_lint( - OVERFLOWING_LITERALS, - e.span, - OverflowingUInt { - ty: t.name_str(), - lit: cx - .sess() - .source_map() - .span_to_snippet(lit.span) - .unwrap_or_else(|_| lit_val.to_string()), - min, - max, - }, - ); - } -} - -fn lint_literal<'tcx>( - cx: &LateContext<'tcx>, - type_limits: &TypeLimits, - e: &'tcx hir::Expr<'tcx>, - lit: &hir::Lit, -) { - match *cx.typeck_results().node_type(e.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()) - } - _ => bug!(), - }; - } - ty::Uint(t) => lint_uint_literal(cx, e, lit, t), - ty::Float(t) => { - let (is_infinite, sym) = match lit.node { - ast::LitKind::Float(v, _) => match t { - // FIXME(f16_f128): add this check once `is_infinite` is reliable (ABI - // issues resolved). - ty::FloatTy::F16 => (Ok(false), v), - ty::FloatTy::F32 => (v.as_str().parse().map(f32::is_infinite), v), - ty::FloatTy::F64 => (v.as_str().parse().map(f64::is_infinite), v), - ty::FloatTy::F128 => (Ok(false), v), - }, - _ => bug!(), - }; - if is_infinite == Ok(true) { - cx.emit_span_lint( - OVERFLOWING_LITERALS, - e.span, - OverflowingLiteral { - ty: t.name_str(), - lit: cx - .sess() - .source_map() - .span_to_snippet(lit.span) - .unwrap_or_else(|_| sym.to_string()), - }, - ); - } - } - _ => {} - } -} - fn lint_nan<'tcx>( cx: &LateContext<'tcx>, e: &'tcx hir::Expr<'tcx>, diff --git a/compiler/rustc_lint/src/types/literal.rs b/compiler/rustc_lint/src/types/literal.rs new file mode 100644 index 0000000000000..67404be24b52e --- /dev/null +++ b/compiler/rustc_lint/src/types/literal.rs @@ -0,0 +1,386 @@ +use hir::{is_range_literal, ExprKind, Node}; +use rustc_middle::ty::layout::IntegerExt; +use rustc_middle::ty::Ty; +use rustc_middle::{bug, ty}; +use rustc_target::abi::{Integer, Size}; +use {rustc_ast as ast, rustc_attr as attr, rustc_hir as hir}; + +use crate::context::LintContext; +use crate::lints::{ + OnlyCastu8ToChar, OverflowingBinHex, OverflowingBinHexSign, OverflowingBinHexSignBitSub, + OverflowingBinHexSub, OverflowingInt, OverflowingIntHelp, OverflowingLiteral, OverflowingUInt, + RangeEndpointOutOfRange, UseInclusiveRange, +}; +use crate::types::{TypeLimits, OVERFLOWING_LITERALS}; +use crate::LateContext; + +/// Attempts to special-case the overflowing literal lint when it occurs as a range endpoint (`expr..MAX+1`). +/// Returns `true` iff the lint was emitted. +fn lint_overflowing_range_endpoint<'tcx>( + cx: &LateContext<'tcx>, + lit: &hir::Lit, + lit_val: u128, + max: u128, + expr: &'tcx hir::Expr<'tcx>, + 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 ExprKind::Cast(_, _) = par_expr.kind + { + (par_expr, expr.span) + } else { + (expr, expr.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::Expr(struct_expr) = cx.tcx.parent_hir_node(field.hir_id) else { return false }; + if !is_range_literal(struct_expr) { + return false; + }; + let ExprKind::Struct(_, [start, end], _) = &struct_expr.kind else { return false }; + + // 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) { + return false; + }; + + use rustc_ast::{LitIntType, LitKind}; + let suffix = match lit.node { + LitKind::Int(_, LitIntType::Signed(s)) => s.name_str(), + LitKind::Int(_, LitIntType::Unsigned(s)) => s.name_str(), + LitKind::Int(_, LitIntType::Unsuffixed) => "", + _ => bug!(), + }; + + let sub_sugg = if expr.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()), + start, + literal: lit_val - 1, + suffix, + } + } else { + UseInclusiveRange::WithParen { + eq_sugg: expr.span.shrink_to_lo(), + lit_sugg: lit_span, + literal: lit_val - 1, + suffix, + } + }; + + cx.emit_span_lint( + OVERFLOWING_LITERALS, + struct_expr.span, + RangeEndpointOutOfRange { ty, sub: sub_sugg }, + ); + + // We've just emitted a lint, special cased for `(...)..MAX+1` ranges, + // return `true` so the callers don't also emit a lint + true +} + +// For `isize` & `usize`, be conservative with the warnings, so that the +// warnings are consistent between 32- and 64-bit platforms. +pub(crate) fn int_ty_range(int_ty: ty::IntTy) -> (i128, i128) { + match int_ty { + ty::IntTy::Isize => (i64::MIN.into(), i64::MAX.into()), + ty::IntTy::I8 => (i8::MIN.into(), i8::MAX.into()), + ty::IntTy::I16 => (i16::MIN.into(), i16::MAX.into()), + ty::IntTy::I32 => (i32::MIN.into(), i32::MAX.into()), + ty::IntTy::I64 => (i64::MIN.into(), i64::MAX.into()), + ty::IntTy::I128 => (i128::MIN, i128::MAX), + } +} + +pub(crate) fn uint_ty_range(uint_ty: ty::UintTy) -> (u128, u128) { + let max = match uint_ty { + ty::UintTy::Usize => u64::MAX.into(), + ty::UintTy::U8 => u8::MAX.into(), + ty::UintTy::U16 => u16::MAX.into(), + ty::UintTy::U32 => u32::MAX.into(), + ty::UintTy::U64 => u64::MAX.into(), + ty::UintTy::U128 => u128::MAX, + }; + (0, max) +} + +fn get_bin_hex_repr(cx: &LateContext<'_>, lit: &hir::Lit) -> Option { + let src = cx.sess().source_map().span_to_snippet(lit.span).ok()?; + let firstch = src.chars().next()?; + + if firstch == '0' { + match src.chars().nth(1) { + Some('x' | 'b') => return Some(src), + _ => return None, + } + } + + None +} + +fn report_bin_hex_error( + cx: &LateContext<'_>, + expr: &hir::Expr<'_>, + ty: attr::IntType, + size: Size, + repr_str: String, + val: u128, + negative: bool, +) { + let (t, actually) = match ty { + attr::IntType::SignedInt(t) => { + let actually = if negative { -(size.sign_extend(val)) } else { size.sign_extend(val) }; + (t.name_str(), actually.to_string()) + } + attr::IntType::UnsignedInt(t) => { + let actually = size.truncate(val); + (t.name_str(), actually.to_string()) + } + }; + 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( + |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 } + } 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 { + return None; + }; + + let Some(bit_width) = int_ty.bit_width() else { + return None; // isize case + }; + + // Skip if sign bit is not set + if (val & (1 << (bit_width - 1))) == 0 { + return None; + } + + let lit_no_suffix = + if let Some(pos) = repr_str.chars().position(|c| c == 'i' || c == 'u') { + repr_str.split_at(pos).0 + } else { + &repr_str + }; + + Some(OverflowingBinHexSignBitSub { + span: expr.span, + lit_no_suffix, + negative_val: actually.clone(), + int_ty: int_ty.name_str(), + uint_ty: int_ty.to_unsigned().name_str(), + }) + }) + .flatten(); + + cx.emit_span_lint( + OVERFLOWING_LITERALS, + expr.span, + OverflowingBinHex { + ty: t, + lit: repr_str.clone(), + dec: val, + actually, + sign, + sub, + sign_bit_sub, + }, + ) +} + +// Find the "next" fitting integer and return a suggestion string +// +// No suggestion is offered for `{i,u}size`. Otherwise, we try to suggest an equal-sized type. +fn get_type_suggestion(t: Ty<'_>, val: u128, negative: bool) -> Option<&'static str> { + match t.kind() { + ty::Uint(ty::UintTy::Usize) | ty::Int(ty::IntTy::Isize) => None, + ty::Uint(_) => Some(Integer::fit_unsigned(val).uint_ty_str()), + ty::Int(_) if negative => Some(Integer::fit_signed(-(val as i128)).int_ty_str()), + ty::Int(int) => { + let signed = Integer::fit_signed(val as i128); + let unsigned = Integer::fit_unsigned(val); + Some(if Some(unsigned.size().bits()) == int.bit_width() { + unsigned.uint_ty_str() + } else { + signed.int_ty_str() + }) + } + _ => None, + } +} + +fn lint_int_literal<'tcx>( + cx: &LateContext<'tcx>, + type_limits: &TypeLimits, + e: &'tcx hir::Expr<'tcx>, + 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); + + // 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, + attr::IntType::SignedInt(ty::ast_int_ty(t)), + Integer::from_int_ty(cx, t).size(), + repr_str, + v, + negative, + ); + return; + } + + if lint_overflowing_range_endpoint(cx, lit, v, max, e, 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 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) + .map(|suggestion_ty| OverflowingIntHelp { suggestion_ty }); + + cx.emit_span_lint( + OVERFLOWING_LITERALS, + span, + OverflowingInt { ty: t.name_str(), lit, min, max, help }, + ); + } +} + +fn lint_uint_literal<'tcx>( + cx: &LateContext<'tcx>, + e: &'tcx hir::Expr<'tcx>, + lit: &hir::Lit, + t: ty::UintTy, +) { + let uint_type = t.normalize(cx.sess().target.pointer_width); + let (min, max) = uint_ty_range(uint_type); + let lit_val: u128 = match lit.node { + // _v is u8, within range by definition + ast::LitKind::Byte(_v) => return, + ast::LitKind::Int(v, _) => v.get(), + _ => bug!(), + }; + + if lit_val < min || lit_val > max { + if let Node::Expr(par_e) = cx.tcx.parent_hir_node(e.hir_id) { + match par_e.kind { + hir::ExprKind::Cast(..) => { + if let ty::Char = cx.typeck_results().expr_ty(par_e).kind() { + cx.emit_span_lint( + OVERFLOWING_LITERALS, + par_e.span, + OnlyCastu8ToChar { span: par_e.span, literal: lit_val }, + ); + return; + } + } + _ => {} + } + } + if lint_overflowing_range_endpoint(cx, lit, lit_val, max, e, 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, + attr::IntType::UnsignedInt(ty::ast_uint_ty(t)), + Integer::from_uint_ty(cx, t).size(), + repr_str, + lit_val, + false, + ); + return; + } + cx.emit_span_lint( + OVERFLOWING_LITERALS, + e.span, + OverflowingUInt { + ty: t.name_str(), + lit: cx + .sess() + .source_map() + .span_to_snippet(lit.span) + .unwrap_or_else(|_| lit_val.to_string()), + min, + max, + }, + ); + } +} + +pub(crate) fn lint_literal<'tcx>( + cx: &LateContext<'tcx>, + type_limits: &TypeLimits, + e: &'tcx hir::Expr<'tcx>, + lit: &hir::Lit, +) { + match *cx.typeck_results().node_type(e.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()) + } + _ => bug!(), + }; + } + ty::Uint(t) => lint_uint_literal(cx, e, lit, t), + ty::Float(t) => { + let (is_infinite, sym) = match lit.node { + ast::LitKind::Float(v, _) => match t { + // FIXME(f16_f128): add this check once `is_infinite` is reliable (ABI + // issues resolved). + ty::FloatTy::F16 => (Ok(false), v), + ty::FloatTy::F32 => (v.as_str().parse().map(f32::is_infinite), v), + ty::FloatTy::F64 => (v.as_str().parse().map(f64::is_infinite), v), + ty::FloatTy::F128 => (Ok(false), v), + }, + _ => bug!(), + }; + if is_infinite == Ok(true) { + cx.emit_span_lint( + OVERFLOWING_LITERALS, + e.span, + OverflowingLiteral { + ty: t.name_str(), + lit: cx + .sess() + .source_map() + .span_to_snippet(lit.span) + .unwrap_or_else(|_| sym.to_string()), + }, + ); + } + } + _ => {} + } +}