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tr: Add ambiguous octal escape warning #6886

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Merged
merged 2 commits into from
Nov 28, 2024
Merged

tr: Add ambiguous octal escape warning #6886

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6954ad9
tr: Add ambiguous octal escape warning, issue #6821
OshinoShinobu-Chan Nov 24, 2024
ee44048
tr: Make code cleaner
OshinoShinobu-Chan Nov 27, 2024
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46 changes: 41 additions & 5 deletions src/uu/tr/src/operation.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,13 +16,15 @@ use nom::{
IResult,
};
use std::{
char,
collections::{HashMap, HashSet},
error::Error,
fmt::{Debug, Display},
io::{BufRead, Write},
ops::Not,
};
use uucore::error::UError;
use uucore::show_warning;

#[derive(Debug, Clone)]
pub enum BadSequence {
Expand Down Expand Up @@ -293,7 +295,9 @@ impl Sequence {
Self::parse_class,
Self::parse_char_equal,
// NOTE: This must be the last one
map(Self::parse_backslash_or_char, |s| Ok(Self::Char(s))),
map(Self::parse_backslash_or_char_with_warning, |s| {
Ok(Self::Char(s))
}),
)))(input)
.map(|(_, r)| r)
.unwrap()
Expand All @@ -302,10 +306,16 @@ impl Sequence {
}

fn parse_octal(input: &[u8]) -> IResult<&[u8], u8> {
// For `parse_char_range`, `parse_char_star`, `parse_char_repeat`, `parse_char_equal`.
// Because in these patterns, there's no ambiguous cases.
preceded(tag("\\"), Self::parse_octal_up_to_three_digits)(input)
}

fn parse_octal_with_warning(input: &[u8]) -> IResult<&[u8], u8> {
preceded(
tag("\\"),
alt((
Self::parse_octal_up_to_three_digits,
Self::parse_octal_up_to_three_digits_with_warning,
// Fallback for if the three digit octal escape is greater than \377 (0xFF), and therefore can't be
// parsed as as a byte
// See test `test_multibyte_octal_sequence`
Expand All @@ -319,13 +329,31 @@ impl Sequence {
recognize(many_m_n(1, 3, one_of("01234567"))),
|out: &[u8]| {
let str_to_parse = std::str::from_utf8(out).unwrap();
match u8::from_str_radix(str_to_parse, 8) {
Ok(ue) => Some(ue),
Err(_pa) => None,
}
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You can simplify this and use ok() to turn the Result into an Option:

Suggested change
match u8::from_str_radix(str_to_parse, 8) {
Ok(ue) => Some(ue),
Err(_pa) => None,
}
u8::from_str_radix(str_to_parse, 8).ok()

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i wonder if there is a clippy warning for this?!

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@sylvestre I'm not aware of such a lint.

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Yes, you are right. I just copied it and removed the previous TODO comment, so I didn't notice that this match is redundant.

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@samueltardieu you might be interested by this :)

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Indeed, this is lacking. I'll add this to my TODO list.

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See rust-lang/rust-clippy#13740

},
)(input)
}

fn parse_octal_up_to_three_digits_with_warning(input: &[u8]) -> IResult<&[u8], u8> {
map_opt(
recognize(many_m_n(1, 3, one_of("01234567"))),
|out: &[u8]| {
let str_to_parse = std::str::from_utf8(out).unwrap();
match u8::from_str_radix(str_to_parse, 8) {
Ok(ue) => Some(ue),
Err(_pa) => {
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I think it is cleaner to simply use Err(_):

Suggested change
Err(_pa) => {
Err(_) => {

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The similar reason to the one above, and I agree with this change too. Thank you for your review and suggestions.

// TODO
// A warning needs to be printed here
// See https://github.com/uutils/coreutils/issues/6821
let origin_octal: &str = std::str::from_utf8(input).unwrap();
let actual_octal_tail: &str = std::str::from_utf8(&input[0..2]).unwrap();
let outstand_char: char = char::from_u32(input[2] as u32).unwrap();
show_warning!(
"the ambiguous octal escape \\{} is being\n interpreted as the 2-byte sequence \\0{}, {}",
origin_octal,
actual_octal_tail,
outstand_char
);
None
}
}
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Here it might be an option to use something like:

let result = u8::from_str_radix(str_to_parse, 8).ok();

if result.is_none() {
     let origin_octal: &str = std::str::from_utf8(input).unwrap();
     let actual_octal_tail: &str = std::str::from_utf8(&input[0..2]).unwrap();
     let outstand_char: char = char::from_u32(input[2] as u32).unwrap();
     show_warning!(
         "the ambiguous octal escape \\{} is being\n        interpreted as the 2-byte sequence \\0{}, {}",
         origin_octal,
         actual_octal_tail,
         outstand_char
     );
}

result

This way you could remove one indentation level.

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I don't think this is necessary. But it does make the code looks nicer. I think I'll accept this suggestion.

Expand Down Expand Up @@ -360,6 +388,14 @@ impl Sequence {
alt((Self::parse_octal, Self::parse_backslash, Self::single_char))(input)
}

fn parse_backslash_or_char_with_warning(input: &[u8]) -> IResult<&[u8], u8> {
alt((
Self::parse_octal_with_warning,
Self::parse_backslash,
Self::single_char,
))(input)
}

fn single_char(input: &[u8]) -> IResult<&[u8], u8> {
take(1usize)(input).map(|(l, a)| (l, a[0]))
}
Expand Down
4 changes: 1 addition & 3 deletions tests/by-util/test_tr.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1494,9 +1494,7 @@ fn test_multibyte_octal_sequence() {
.args(&["-d", r"\501"])
.pipe_in("(1Ł)")
.succeeds()
// TODO
// A warning needs to be printed here
// See https://github.com/uutils/coreutils/issues/6821
.stderr_is("tr: warning: the ambiguous octal escape \\501 is being\n interpreted as the 2-byte sequence \\050, 1\n")
.stdout_is("Ł)");
}

Expand Down
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