rust/crates/ra_syntax/src/validation.rs
Aleksey Kladov af53d5f4b0 Rename
2020-07-31 20:23:52 +02:00

304 lines
10 KiB
Rust

//! FIXME: write short doc here
mod block;
use crate::{
ast, match_ast, AstNode, SyntaxError,
SyntaxKind::{BYTE, BYTE_STRING, CHAR, CONST, FN, INT_NUMBER, STRING, TYPE_ALIAS},
SyntaxNode, SyntaxToken, TextSize, T,
};
use rustc_lexer::unescape::{
self, unescape_byte, unescape_byte_literal, unescape_char, unescape_literal, Mode,
};
use std::convert::TryFrom;
fn rustc_unescape_error_to_string(err: unescape::EscapeError) -> &'static str {
use unescape::EscapeError as EE;
#[rustfmt::skip]
let err_message = match err {
EE::ZeroChars => {
"Literal must not be empty"
}
EE::MoreThanOneChar => {
"Literal must be one character long"
}
EE::LoneSlash => {
"Character must be escaped: `\\`"
}
EE::InvalidEscape => {
"Invalid escape"
}
EE::BareCarriageReturn | EE::BareCarriageReturnInRawString => {
"Character must be escaped: `\r`"
}
EE::EscapeOnlyChar => {
"Escape character `\\` must be escaped itself"
}
EE::TooShortHexEscape => {
"ASCII hex escape code must have exactly two digits"
}
EE::InvalidCharInHexEscape => {
"ASCII hex escape code must contain only hex characters"
}
EE::OutOfRangeHexEscape => {
"ASCII hex escape code must be at most 0x7F"
}
EE::NoBraceInUnicodeEscape => {
"Missing `{` to begin the unicode escape"
}
EE::InvalidCharInUnicodeEscape => {
"Unicode escape must contain only hex characters and underscores"
}
EE::EmptyUnicodeEscape => {
"Unicode escape must not be empty"
}
EE::UnclosedUnicodeEscape => {
"Missing `}` to terminate the unicode escape"
}
EE::LeadingUnderscoreUnicodeEscape => {
"Unicode escape code must not begin with an underscore"
}
EE::OverlongUnicodeEscape => {
"Unicode escape code must have at most 6 digits"
}
EE::LoneSurrogateUnicodeEscape => {
"Unicode escape code must not be a surrogate"
}
EE::OutOfRangeUnicodeEscape => {
"Unicode escape code must be at most 0x10FFFF"
}
EE::UnicodeEscapeInByte => {
"Byte literals must not contain unicode escapes"
}
EE::NonAsciiCharInByte | EE::NonAsciiCharInByteString => {
"Byte literals must not contain non-ASCII characters"
}
};
err_message
}
pub(crate) fn validate(root: &SyntaxNode) -> Vec<SyntaxError> {
// FIXME:
// * Add unescape validation of raw string literals and raw byte string literals
// * Add validation of doc comments are being attached to nodes
let mut errors = Vec::new();
for node in root.descendants() {
match_ast! {
match node {
ast::Literal(it) => validate_literal(it, &mut errors),
ast::BlockExpr(it) => block::validate_block_expr(it, &mut errors),
ast::FieldExpr(it) => validate_numeric_name(it.name_ref(), &mut errors),
ast::RecordExprField(it) => validate_numeric_name(it.name_ref(), &mut errors),
ast::Visibility(it) => validate_visibility(it, &mut errors),
ast::RangeExpr(it) => validate_range_expr(it, &mut errors),
ast::PathSegment(it) => validate_path_keywords(it, &mut errors),
_ => (),
}
}
}
errors
}
fn validate_literal(literal: ast::Literal, acc: &mut Vec<SyntaxError>) {
// FIXME: move this function to outer scope (https://github.com/rust-analyzer/rust-analyzer/pull/2834#discussion_r366196658)
fn unquote(text: &str, prefix_len: usize, end_delimiter: char) -> Option<&str> {
text.rfind(end_delimiter).and_then(|end| text.get(prefix_len..end))
}
let token = literal.token();
let text = token.text().as_str();
// FIXME: lift this lambda refactor to `fn` (https://github.com/rust-analyzer/rust-analyzer/pull/2834#discussion_r366199205)
let mut push_err = |prefix_len, (off, err): (usize, unescape::EscapeError)| {
let off = token.text_range().start() + TextSize::try_from(off + prefix_len).unwrap();
acc.push(SyntaxError::new_at_offset(rustc_unescape_error_to_string(err), off));
};
match token.kind() {
BYTE => {
if let Some(Err(e)) = unquote(text, 2, '\'').map(unescape_byte) {
push_err(2, e);
}
}
CHAR => {
if let Some(Err(e)) = unquote(text, 1, '\'').map(unescape_char) {
push_err(1, e);
}
}
BYTE_STRING => {
if let Some(without_quotes) = unquote(text, 2, '"') {
unescape_byte_literal(without_quotes, Mode::ByteStr, &mut |range, char| {
if let Err(err) = char {
push_err(2, (range.start, err));
}
})
}
}
STRING => {
if let Some(without_quotes) = unquote(text, 1, '"') {
unescape_literal(without_quotes, Mode::Str, &mut |range, char| {
if let Err(err) = char {
push_err(1, (range.start, err));
}
})
}
}
_ => (),
}
}
pub(crate) fn validate_block_structure(root: &SyntaxNode) {
let mut stack = Vec::new();
for node in root.descendants() {
match node.kind() {
T!['{'] => stack.push(node),
T!['}'] => {
if let Some(pair) = stack.pop() {
assert_eq!(
node.parent(),
pair.parent(),
"\nunpaired curleys:\n{}\n{:#?}\n",
root.text(),
root,
);
assert!(
node.next_sibling().is_none() && pair.prev_sibling().is_none(),
"\nfloating curlys at {:?}\nfile:\n{}\nerror:\n{}\n",
node,
root.text(),
node.text(),
);
}
}
_ => (),
}
}
}
fn validate_numeric_name(name_ref: Option<ast::NameRef>, errors: &mut Vec<SyntaxError>) {
if let Some(int_token) = int_token(name_ref) {
if int_token.text().chars().any(|c| !c.is_digit(10)) {
errors.push(SyntaxError::new(
"Tuple (struct) field access is only allowed through \
decimal integers with no underscores or suffix",
int_token.text_range(),
));
}
}
fn int_token(name_ref: Option<ast::NameRef>) -> Option<SyntaxToken> {
name_ref?.syntax().first_child_or_token()?.into_token().filter(|it| it.kind() == INT_NUMBER)
}
}
fn validate_visibility(vis: ast::Visibility, errors: &mut Vec<SyntaxError>) {
let parent = match vis.syntax().parent() {
Some(it) => it,
None => return,
};
match parent.kind() {
FN | CONST | TYPE_ALIAS => (),
_ => return,
}
let impl_def = match parent.parent().and_then(|it| it.parent()).and_then(ast::Impl::cast) {
Some(it) => it,
None => return,
};
if impl_def.trait_().is_some() {
errors.push(SyntaxError::new("Unnecessary visibility qualifier", vis.syntax.text_range()));
}
}
fn validate_range_expr(expr: ast::RangeExpr, errors: &mut Vec<SyntaxError>) {
if expr.op_kind() == Some(ast::RangeOp::Inclusive) && expr.end().is_none() {
errors.push(SyntaxError::new(
"An inclusive range must have an end expression",
expr.syntax().text_range(),
));
}
}
fn validate_path_keywords(segment: ast::PathSegment, errors: &mut Vec<SyntaxError>) {
use ast::PathSegmentKind;
let path = segment.parent_path();
let is_path_start = segment.coloncolon_token().is_none() && path.qualifier().is_none();
if let Some(token) = segment.self_token() {
if !is_path_start {
errors.push(SyntaxError::new(
"The `self` keyword is only allowed as the first segment of a path",
token.text_range(),
));
}
} else if let Some(token) = segment.crate_token() {
if !is_path_start || use_prefix(path).is_some() {
errors.push(SyntaxError::new(
"The `crate` keyword is only allowed as the first segment of a path",
token.text_range(),
));
}
} else if let Some(token) = segment.super_token() {
if !all_supers(&path) {
errors.push(SyntaxError::new(
"The `super` keyword may only be preceded by other `super`s",
token.text_range(),
));
return;
}
let mut curr_path = path;
while let Some(prefix) = use_prefix(curr_path) {
if !all_supers(&prefix) {
errors.push(SyntaxError::new(
"The `super` keyword may only be preceded by other `super`s",
token.text_range(),
));
return;
}
curr_path = prefix;
}
}
fn use_prefix(mut path: ast::Path) -> Option<ast::Path> {
for node in path.syntax().ancestors().skip(1) {
match_ast! {
match node {
ast::UseTree(it) => if let Some(tree_path) = it.path() {
// Even a top-level path exists within a `UseTree` so we must explicitly
// allow our path but disallow anything else
if tree_path != path {
return Some(tree_path);
}
},
ast::UseTreeList(_it) => continue,
ast::Path(parent) => path = parent,
_ => return None,
}
};
}
return None;
}
fn all_supers(path: &ast::Path) -> bool {
let segment = match path.segment() {
Some(it) => it,
None => return false,
};
if segment.kind() != Some(PathSegmentKind::SuperKw) {
return false;
}
if let Some(ref subpath) = path.qualifier() {
return all_supers(subpath);
}
return true;
}
}