//! 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;
+use rustc_ast::ast::{Expr, ExprKind, Lit, LitKind};
use rustc_errors::Applicability;
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};
-use syntax::ast::*;
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]
- fn suggest_grouping(&self) -> usize {
- match *self {
- Self::Binary | Self::Hexadecimal => 4,
- Self::Octal | Self::Decimal => 3,
- }
- }
-}
-
-/// A helper method to format numeric literals with digit grouping.
-/// `lit` must be a valid numeric literal without suffix.
-pub fn format_numeric_literal(lit: &str, type_suffix: Option<&str>, float: bool) -> String {
- NumericLiteral::new(lit, type_suffix, float).format()
-}
-
-#[derive(Debug)]
-pub(super) struct NumericLiteral<'a> {
- /// Which radix the literal was represented in.
- radix: Radix,
- /// The radix prefix, if present.
- 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.
- 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]
- 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.
- fn format(&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() - 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,
}
}
+// 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) {
if_chain! {
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('_'))?;
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('_');
}
}
+ /// 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.
projects / rust.git / blobdiff