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|
use std::u32;
use crate::{
algo::visit::{visitor_ctx, VisitorCtx},
ast::{self, AstNode},
File,
string_lexing::{self, CharComponentKind},
utils::MutAsciiString,
yellow::{
SyntaxError,
SyntaxErrorKind::*,
},
};
pub(crate) fn validate(file: &File) -> Vec<SyntaxError> {
let mut errors = Vec::new();
for node in file.root.borrowed().descendants() {
let _ = visitor_ctx(&mut errors)
.visit::<ast::Char, _>(validate_char)
.accept(node);
}
errors
}
fn validate_char(node: ast::Char, errors: &mut Vec<SyntaxError>) {
let mut components = string_lexing::parse_char_literal(node.text());
let mut len = 0;
for component in &mut components {
len += 1;
// Validate escapes
let text = &node.text()[component.range];
let range = component.range + node.syntax().range().start();
use self::CharComponentKind::*;
match component.kind {
AsciiEscape => {
if text.len() == 1 {
// Escape sequence consists only of leading `\`
errors.push(SyntaxError::new(EmptyAsciiEscape, range));
} else {
let escape_code = text.chars().skip(1).next().unwrap();
if !is_ascii_escape(escape_code) {
errors.push(SyntaxError::new(InvalidAsciiEscape, range));
}
}
}
AsciiCodeEscape => {
// An AsciiCodeEscape has 4 chars, example: `\xDD`
if text.len() < 4 {
errors.push(SyntaxError::new(TooShortAsciiCodeEscape, range));
} else {
assert!(text.chars().count() == 4, "AsciiCodeEscape cannot be longer than 4 chars");
match u8::from_str_radix(&text[2..], 16) {
Ok(code) if code < 128 => { /* Escape code is valid */ },
Ok(_) => errors.push(SyntaxError::new(AsciiCodeEscapeOutOfRange, range)),
Err(_) => errors.push(SyntaxError::new(MalformedAsciiCodeEscape, range)),
}
}
}
UnicodeEscape => {
assert!(&text[..2] == "\\u", "UnicodeEscape always starts with \\u");
if text.len() == 2 {
// No starting `{`
errors.push(SyntaxError::new(MalformedUnicodeEscape, range));
return;
}
if text.len() == 3 {
// Only starting `{`
errors.push(SyntaxError::new(UnclosedUnicodeEscape, range));
return;
}
let mut buf = &mut [0; 6];
let mut code = MutAsciiString::new(buf);
let mut closed = false;
for c in text[3..].chars() {
assert!(!closed, "no characters after escape is closed");
if c.is_digit(16) {
if code.len() == 6 {
errors.push(SyntaxError::new(OverlongUnicodeEscape, range));
return;
}
code.push(c);
} else if c == '_' {
// Reject leading _
if code.len() == 0 {
errors.push(SyntaxError::new(MalformedUnicodeEscape, range));
return;
}
} else if c == '}' {
closed = true;
} else {
errors.push(SyntaxError::new(MalformedUnicodeEscape, range));
return;
}
}
if !closed {
errors.push(SyntaxError::new(UnclosedUnicodeEscape, range))
}
if code.len() == 0 {
errors.push(SyntaxError::new(EmptyUnicodeEcape, range));
return;
}
match u32::from_str_radix(&code, 16) {
Ok(code_u32) if code_u32 > 0x10FFFF => {
errors.push(SyntaxError::new(UnicodeEscapeOutOfRange, range));
}
Ok(_) => {
// Valid escape code
}
Err(_) => {
errors.push(SyntaxError::new(MalformedUnicodeEscape, range));
}
}
// FIXME: we really need tests for this
}
// Code points are always valid
CodePoint => (),
}
}
if !components.has_closing_quote {
errors.push(SyntaxError::new(UnclosedChar, node.syntax().range()));
}
if len == 0 {
errors.push(SyntaxError::new(EmptyChar, node.syntax().range()));
}
if len > 1 {
errors.push(SyntaxError::new(LongChar, node.syntax().range()));
}
}
fn is_ascii_escape(code: char) -> bool {
match code {
'\'' | '"' | 'n' | 'r' | 't' | '0' => true,
_ => false,
}
}
|
