//! Lints concerned with the grouping of digits with underscores in integral or
//! floating-point literal expressions.
-use crate::utils::{in_macro, snippet_opt, span_lint_and_sugg};
+use crate::utils::{
+ in_macro,
+ numeric_literal::{NumericLiteral, Radix},
+ snippet_opt, span_lint_and_sugg,
+};
use if_chain::if_chain;
-use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass};
-use rustc::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
+use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
use rustc_errors::Applicability;
-use syntax::ast::*;
-use syntax_pos;
+use rustc_lint::{EarlyContext, EarlyLintPass, LintContext};
+use rustc_middle::lint::in_external_macro;
+use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass};
declare_clippy_lint! {
/// **What it does:** Warns if a long integral or floating-point constant does
/// **Example:**
///
/// ```rust
+ /// // Bad
/// let x: u64 = 61864918973511;
+ ///
+ /// // Good
+ /// let x: u64 = 61_864_918_973_511;
/// ```
pub UNREADABLE_LITERAL,
- style,
+ pedantic,
"long integer literal without underscores"
}
/// **Known problems:**
/// - Recommends a signed suffix, even though the number might be too big and an unsigned
/// suffix is required
- /// - Does not match on `_128` since that is a valid grouping for decimal and octal numbers
+ /// - Does not match on `_127` since that is a valid grouping for decimal and octal numbers
///
/// **Example:**
///
/// ```rust
+ /// // Probably mistyped
/// 2_32;
+ ///
+ /// // Good
+ /// 2_i32;
/// ```
pub MISTYPED_LITERAL_SUFFIXES,
correctness,
/// **Example:**
///
/// ```rust
+ /// // Bad
/// let x: u64 = 618_64_9189_73_511;
+ ///
+ /// // Good
+ /// let x: u64 = 61_864_918_973_511;
/// ```
pub INCONSISTENT_DIGIT_GROUPING,
style,
"using decimal representation when hexadecimal would be better"
}
-#[derive(Debug, PartialEq)]
-pub(super) enum Radix {
- Binary,
- Octal,
- Decimal,
- Hexadecimal,
-}
-
-impl Radix {
- /// Returns a reasonable digit group size for this radix.
- #[must_use]
- crate fn suggest_grouping(&self) -> usize {
- match *self {
- Self::Binary | Self::Hexadecimal => 4,
- Self::Octal | Self::Decimal => 3,
- }
- }
-}
-
-#[derive(Debug)]
-pub(super) struct NumericLiteral<'a> {
- /// Which radix the literal was represented in.
- crate radix: Radix,
- /// The radix prefix, if present.
- crate prefix: Option<&'a str>,
-
- /// The integer part of the number.
- integer: &'a str,
- /// The fraction part of the number.
- fraction: Option<&'a str>,
- /// The character used as exponent seperator (b'e' or b'E') and the exponent part.
- exponent: Option<(char, &'a str)>,
-
- /// The type suffix, including preceding underscore if present.
- crate suffix: Option<&'a str>,
-}
-
-impl<'a> NumericLiteral<'a> {
- fn from_lit(src: &'a str, lit: &Lit) -> Option<NumericLiteral<'a>> {
- if lit.kind.is_numeric() && src.chars().next().map_or(false, |c| c.is_digit(10)) {
- let (unsuffixed, suffix) = split_suffix(&src, &lit.kind);
- let float = if let LitKind::Float(..) = lit.kind { true } else { false };
- Some(NumericLiteral::new(unsuffixed, suffix, float))
- } else {
- None
- }
- }
-
- #[must_use]
- crate fn new(lit: &'a str, suffix: Option<&'a str>, float: bool) -> Self {
- // Determine delimiter for radix prefix, if present, and radix.
- let radix = if lit.starts_with("0x") {
- Radix::Hexadecimal
- } else if lit.starts_with("0b") {
- Radix::Binary
- } else if lit.starts_with("0o") {
- Radix::Octal
- } else {
- Radix::Decimal
- };
-
- // Grab part of the literal after prefix, if present.
- let (prefix, mut sans_prefix) = if let Radix::Decimal = radix {
- (None, lit)
- } else {
- let (p, s) = lit.split_at(2);
- (Some(p), s)
- };
-
- if suffix.is_some() && sans_prefix.ends_with('_') {
- // The '_' before the suffix isn't part of the digits
- sans_prefix = &sans_prefix[..sans_prefix.len() - 1];
- }
-
- let (integer, fraction, exponent) = Self::split_digit_parts(sans_prefix, float);
-
- Self {
- radix,
- prefix,
- integer,
- fraction,
- exponent,
- suffix,
- }
- }
-
- fn split_digit_parts(digits: &str, float: bool) -> (&str, Option<&str>, Option<(char, &str)>) {
- let mut integer = digits;
- let mut fraction = None;
- let mut exponent = None;
-
- if float {
- for (i, c) in digits.char_indices() {
- match c {
- '.' => {
- integer = &digits[..i];
- fraction = Some(&digits[i + 1..]);
- },
- 'e' | 'E' => {
- if integer.len() > i {
- integer = &digits[..i];
- } else {
- fraction = Some(&digits[integer.len() + 1..i]);
- };
- exponent = Some((c, &digits[i + 1..]));
- break;
- },
- _ => {},
- }
- }
- }
-
- (integer, fraction, exponent)
- }
-
- /// Returns literal formatted in a sensible way.
- crate fn grouping_hint(&self) -> String {
- let mut output = String::new();
-
- if let Some(prefix) = self.prefix {
- output.push_str(prefix);
- }
-
- let group_size = self.radix.suggest_grouping();
-
- Self::group_digits(
- &mut output,
- self.integer,
- group_size,
- true,
- self.radix == Radix::Hexadecimal,
- );
-
- if let Some(fraction) = self.fraction {
- output.push('.');
- Self::group_digits(&mut output, fraction, group_size, false, false);
- }
-
- if let Some((separator, exponent)) = self.exponent {
- output.push(separator);
- Self::group_digits(&mut output, exponent, group_size, true, false);
- }
-
- if let Some(suffix) = self.suffix {
- output.push('_');
- output.push_str(suffix);
- }
-
- output
- }
-
- fn group_digits(output: &mut String, input: &str, group_size: usize, partial_group_first: bool, pad: bool) {
- debug_assert!(group_size > 0);
-
- let mut digits = input.chars().filter(|&c| c != '_');
-
- let first_group_size;
-
- if partial_group_first {
- first_group_size = (digits.clone().count() + group_size - 1) % group_size + 1;
- if pad {
- for _ in 0..group_size - first_group_size {
- output.push('0');
- }
- }
- } else {
- first_group_size = group_size;
- }
-
- for _ in 0..first_group_size {
- if let Some(digit) = digits.next() {
- output.push(digit);
- }
- }
-
- for (c, i) in digits.zip((0..group_size).cycle()) {
- if i == 0 {
- output.push('_');
- }
- output.push(c);
- }
- }
-}
-
-fn split_suffix<'a>(src: &'a str, lit_kind: &LitKind) -> (&'a str, Option<&'a str>) {
- debug_assert!(lit_kind.is_numeric());
- if let Some(suffix_length) = lit_suffix_length(lit_kind) {
- let (unsuffixed, suffix) = src.split_at(src.len() - suffix_length);
- (unsuffixed, Some(suffix))
- } else {
- (src, None)
- }
-}
-
-fn lit_suffix_length(lit_kind: &LitKind) -> Option<usize> {
- debug_assert!(lit_kind.is_numeric());
- let suffix = match lit_kind {
- LitKind::Int(_, int_lit_kind) => match int_lit_kind {
- LitIntType::Signed(int_ty) => Some(int_ty.name_str()),
- LitIntType::Unsigned(uint_ty) => Some(uint_ty.name_str()),
- LitIntType::Unsuffixed => None,
- },
- LitKind::Float(_, float_lit_kind) => match float_lit_kind {
- LitFloatType::Suffixed(float_ty) => Some(float_ty.name_str()),
- LitFloatType::Unsuffixed => None,
- },
- _ => None,
- };
-
- suffix.map(str::len)
-}
-
enum WarningType {
UnreadableLiteral,
InconsistentDigitGrouping,
}
impl WarningType {
- crate fn display(&self, grouping_hint: &str, cx: &EarlyContext<'_>, span: syntax_pos::Span) {
+ fn display(&self, suggested_format: String, cx: &EarlyContext<'_>, span: rustc_span::Span) {
match self {
Self::MistypedLiteralSuffix => span_lint_and_sugg(
cx,
span,
"mistyped literal suffix",
"did you mean to write",
- grouping_hint.to_string(),
+ suggested_format,
Applicability::MaybeIncorrect,
),
Self::UnreadableLiteral => span_lint_and_sugg(
span,
"long literal lacking separators",
"consider",
- grouping_hint.to_owned(),
+ suggested_format,
Applicability::MachineApplicable,
),
Self::LargeDigitGroups => span_lint_and_sugg(
span,
"digit groups should be smaller",
"consider",
- grouping_hint.to_owned(),
+ suggested_format,
Applicability::MachineApplicable,
),
Self::InconsistentDigitGrouping => span_lint_and_sugg(
span,
"digits grouped inconsistently by underscores",
"consider",
- grouping_hint.to_owned(),
+ suggested_format,
Applicability::MachineApplicable,
),
Self::DecimalRepresentation => span_lint_and_sugg(
span,
"integer literal has a better hexadecimal representation",
"consider",
- grouping_hint.to_owned(),
+ suggested_format,
Applicability::MachineApplicable,
),
};
}
}
+// Length of each UUID hyphenated group in hex digits.
+const UUID_GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
+
impl LiteralDigitGrouping {
fn check_lit(cx: &EarlyContext<'_>, lit: &Lit) {
- let in_macro = in_macro(lit.span);
-
if_chain! {
if let Some(src) = snippet_opt(cx, lit.span);
if let Some(mut num_lit) = NumericLiteral::from_lit(&src, &lit);
return;
}
+ if Self::is_literal_uuid_formatted(&mut num_lit) {
+ return;
+ }
+
let result = (|| {
- let integral_group_size = Self::get_group_size(num_lit.integer.split('_'), in_macro)?;
+ let integral_group_size = Self::get_group_size(num_lit.integer.split('_'))?;
if let Some(fraction) = num_lit.fraction {
- let fractional_group_size = Self::get_group_size(fraction.rsplit('_'), in_macro)?;
+ let fractional_group_size = Self::get_group_size(fraction.rsplit('_'))?;
let consistent = Self::parts_consistent(integral_group_size,
fractional_group_size,
if let Err(warning_type) = result {
- warning_type.display(&num_lit.grouping_hint(), cx, lit.span)
+ let should_warn = match warning_type {
+ | WarningType::UnreadableLiteral
+ | WarningType::InconsistentDigitGrouping
+ | WarningType::LargeDigitGroups => {
+ !in_macro(lit.span)
+ }
+ WarningType::DecimalRepresentation | WarningType::MistypedLiteralSuffix => {
+ true
+ }
+ };
+ if should_warn {
+ warning_type.display(num_lit.format(), cx, lit.span)
+ }
}
}
}
// Returns `false` if the check fails
fn check_for_mistyped_suffix(
cx: &EarlyContext<'_>,
- span: syntax_pos::Span,
+ span: rustc_span::Span,
num_lit: &mut NumericLiteral<'_>,
) -> bool {
if num_lit.suffix.is_some() {
let (part, mistyped_suffixes, missing_char) = if let Some((_, exponent)) = &mut num_lit.exponent {
(exponent, &["32", "64"][..], 'f')
- } else if let Some(fraction) = &mut num_lit.fraction {
- (fraction, &["32", "64"][..], 'f')
} else {
- (&mut num_lit.integer, &["8", "16", "32", "64"][..], 'i')
+ num_lit
+ .fraction
+ .as_mut()
+ .map_or((&mut num_lit.integer, &["8", "16", "32", "64"][..], 'i'), |fraction| {
+ (fraction, &["32", "64"][..], 'f')
+ })
};
let mut split = part.rsplit('_');
let last_group = split.next().expect("At least one group");
if split.next().is_some() && mistyped_suffixes.contains(&last_group) {
*part = &part[..part.len() - last_group.len()];
- let mut hint = num_lit.grouping_hint();
- hint.push('_');
- hint.push(missing_char);
- hint.push_str(last_group);
- WarningType::MistypedLiteralSuffix.display(&hint, cx, span);
+ let mut sugg = num_lit.format();
+ sugg.push('_');
+ sugg.push(missing_char);
+ sugg.push_str(last_group);
+ WarningType::MistypedLiteralSuffix.display(sugg, cx, span);
false
} else {
true
}
}
+ /// Checks whether the numeric literal matches the formatting of a UUID.
+ ///
+ /// Returns `true` if the radix is hexadecimal, and the groups match the
+ /// UUID format of 8-4-4-4-12.
+ fn is_literal_uuid_formatted(num_lit: &mut NumericLiteral<'_>) -> bool {
+ if num_lit.radix != Radix::Hexadecimal {
+ return false;
+ }
+
+ // UUIDs should not have a fraction
+ if num_lit.fraction.is_some() {
+ return false;
+ }
+
+ let group_sizes: Vec<usize> = num_lit.integer.split('_').map(str::len).collect();
+ if UUID_GROUP_LENS.len() == group_sizes.len() {
+ UUID_GROUP_LENS.iter().zip(&group_sizes).all(|(&a, &b)| a == b)
+ } else {
+ false
+ }
+ }
+
/// Given the sizes of the digit groups of both integral and fractional
/// parts, and the length
/// of both parts, determine if the digits have been grouped consistently.
/// Returns the size of the digit groups (or None if ungrouped) if successful,
/// otherwise returns a `WarningType` for linting.
- fn get_group_size<'a>(groups: impl Iterator<Item = &'a str>, in_macro: bool) -> Result<Option<usize>, WarningType> {
+ fn get_group_size<'a>(groups: impl Iterator<Item = &'a str>) -> Result<Option<usize>, WarningType> {
let mut groups = groups.map(str::len);
let first = groups.next().expect("At least one group");
} else {
Ok(Some(second))
}
- } else if first > 5 && !in_macro {
+ } else if first > 5 {
Err(WarningType::UnreadableLiteral)
} else {
Ok(None)
if val >= u128::from(self.threshold);
then {
let hex = format!("{:#X}", val);
- let num_lit = NumericLiteral::new(&hex, None, false);
+ let num_lit = NumericLiteral::new(&hex, num_lit.suffix, false);
let _ = Self::do_lint(num_lit.integer).map_err(|warning_type| {
- warning_type.display(&num_lit.grouping_hint(), cx, lit.span)
+ warning_type.display(num_lit.format(), cx, lit.span)
});
}
}
projects / rust.git / blobdiff