servo/components/style/error_reporting.rs

221 lines
11 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//! Types used to report parsing errors.
#![deny(missing_docs)]
use cssparser::{Token, SourceLocation, ParseErrorKind, BasicParseErrorKind};
use log;
use std::fmt;
use style_traits::ParseError;
use stylesheets::UrlExtraData;
/// Errors that can be encountered while parsing CSS.
pub enum ContextualParseError<'a> {
/// A property declaration was not recognized.
UnsupportedPropertyDeclaration(&'a str, ParseError<'a>),
/// A font face descriptor was not recognized.
UnsupportedFontFaceDescriptor(&'a str, ParseError<'a>),
/// A font feature values descriptor was not recognized.
UnsupportedFontFeatureValuesDescriptor(&'a str, ParseError<'a>),
/// A keyframe rule was not valid.
InvalidKeyframeRule(&'a str, ParseError<'a>),
/// A font feature values rule was not valid.
InvalidFontFeatureValuesRule(&'a str, ParseError<'a>),
/// A keyframe property declaration was not recognized.
UnsupportedKeyframePropertyDeclaration(&'a str, ParseError<'a>),
/// A rule was invalid for some reason.
InvalidRule(&'a str, ParseError<'a>),
/// A rule was not recognized.
UnsupportedRule(&'a str, ParseError<'a>),
/// A viewport descriptor declaration was not recognized.
UnsupportedViewportDescriptorDeclaration(&'a str, ParseError<'a>),
/// A counter style descriptor declaration was not recognized.
UnsupportedCounterStyleDescriptorDeclaration(&'a str, ParseError<'a>),
/// A counter style rule had no symbols.
InvalidCounterStyleWithoutSymbols(String),
/// A counter style rule had less than two symbols.
InvalidCounterStyleNotEnoughSymbols(String),
/// A counter style rule did not have additive-symbols.
InvalidCounterStyleWithoutAdditiveSymbols,
/// A counter style rule had extends with symbols.
InvalidCounterStyleExtendsWithSymbols,
/// A counter style rule had extends with additive-symbols.
InvalidCounterStyleExtendsWithAdditiveSymbols,
/// A media rule was invalid for some reason.
InvalidMediaRule(&'a str, ParseError<'a>),
}
impl<'a> fmt::Display for ContextualParseError<'a> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fn token_to_str(t: &Token, f: &mut fmt::Formatter) -> fmt::Result {
match *t {
Token::Ident(ref i) => write!(f, "identifier {}", i),
Token::AtKeyword(ref kw) => write!(f, "keyword @{}", kw),
Token::Hash(ref h) => write!(f, "hash #{}", h),
Token::IDHash(ref h) => write!(f, "id selector #{}", h),
Token::QuotedString(ref s) => write!(f, "quoted string \"{}\"", s),
Token::UnquotedUrl(ref u) => write!(f, "url {}", u),
Token::Delim(ref d) => write!(f, "delimiter {}", d),
Token::Number { int_value: Some(i), .. } => write!(f, "number {}", i),
Token::Number { value, .. } => write!(f, "number {}", value),
Token::Percentage { int_value: Some(i), .. } => write!(f, "percentage {}", i),
Token::Percentage { unit_value, .. } => write!(f, "percentage {}", unit_value * 100.),
Token::Dimension { value, ref unit, .. } => write!(f, "dimension {}{}", value, unit),
Token::WhiteSpace(_) => write!(f, "whitespace"),
Token::Comment(_) => write!(f, "comment"),
Token::Colon => write!(f, "colon (:)"),
Token::Semicolon => write!(f, "semicolon (;)"),
Token::Comma => write!(f, "comma (,)"),
Token::IncludeMatch => write!(f, "include match (~=)"),
Token::DashMatch => write!(f, "dash match (|=)"),
Token::PrefixMatch => write!(f, "prefix match (^=)"),
Token::SuffixMatch => write!(f, "suffix match ($=)"),
Token::SubstringMatch => write!(f, "substring match (*=)"),
Token::Column => write!(f, "column (||)"),
Token::CDO => write!(f, "CDO (<!--)"),
Token::CDC => write!(f, "CDC (-->)"),
Token::Function(ref name) => write!(f, "function {}", name),
Token::ParenthesisBlock => write!(f, "parenthesis ("),
Token::SquareBracketBlock => write!(f, "square bracket ["),
Token::CurlyBracketBlock => write!(f, "curly bracket {{"),
Token::BadUrl(ref _u) => write!(f, "bad url parse error"),
Token::BadString(ref _s) => write!(f, "bad string parse error"),
Token::CloseParenthesis => write!(f, "unmatched close parenthesis"),
Token::CloseSquareBracket => write!(f, "unmatched close square bracket"),
Token::CloseCurlyBracket => write!(f, "unmatched close curly bracket"),
}
}
fn parse_error_to_str(err: &ParseError, f: &mut fmt::Formatter) -> fmt::Result {
match err.kind {
ParseErrorKind::Basic(BasicParseErrorKind::UnexpectedToken(ref t)) => {
write!(f, "found unexpected ")?;
token_to_str(t, f)
}
ParseErrorKind::Basic(BasicParseErrorKind::EndOfInput) => {
write!(f, "unexpected end of input")
}
ParseErrorKind::Basic(BasicParseErrorKind::AtRuleInvalid(ref i)) => {
write!(f, "@ rule invalid: {}", i)
}
ParseErrorKind::Basic(BasicParseErrorKind::AtRuleBodyInvalid) => {
write!(f, "@ rule invalid")
}
ParseErrorKind::Basic(BasicParseErrorKind::QualifiedRuleInvalid) => {
write!(f, "qualified rule invalid")
}
ParseErrorKind::Custom(ref err) => {
write!(f, "{:?}", err)
}
}
}
match *self {
ContextualParseError::UnsupportedPropertyDeclaration(decl, ref err) => {
write!(f, "Unsupported property declaration: '{}', ", decl)?;
parse_error_to_str(err, f)
}
ContextualParseError::UnsupportedFontFaceDescriptor(decl, ref err) => {
write!(f, "Unsupported @font-face descriptor declaration: '{}', ", decl)?;
parse_error_to_str(err, f)
}
ContextualParseError::UnsupportedFontFeatureValuesDescriptor(decl, ref err) => {
write!(f, "Unsupported @font-feature-values descriptor declaration: '{}', ", decl)?;
parse_error_to_str(err, f)
}
ContextualParseError::InvalidKeyframeRule(rule, ref err) => {
write!(f, "Invalid keyframe rule: '{}', ", rule)?;
parse_error_to_str(err, f)
}
ContextualParseError::InvalidFontFeatureValuesRule(rule, ref err) => {
write!(f, "Invalid font feature value rule: '{}', ", rule)?;
parse_error_to_str(err, f)
}
ContextualParseError::UnsupportedKeyframePropertyDeclaration(decl, ref err) => {
write!(f, "Unsupported keyframe property declaration: '{}', ", decl)?;
parse_error_to_str(err, f)
}
ContextualParseError::InvalidRule(rule, ref err) => {
write!(f, "Invalid rule: '{}', ", rule)?;
parse_error_to_str(err, f)
}
ContextualParseError::UnsupportedRule(rule, ref err) => {
write!(f, "Unsupported rule: '{}', ", rule)?;
parse_error_to_str(err, f)
}
ContextualParseError::UnsupportedViewportDescriptorDeclaration(decl, ref err) => {
write!(f, "Unsupported @viewport descriptor declaration: '{}', ", decl)?;
parse_error_to_str(err, f)
}
ContextualParseError::UnsupportedCounterStyleDescriptorDeclaration(decl, ref err) => {
write!(f, "Unsupported @counter-style descriptor declaration: '{}', ", decl)?;
parse_error_to_str(err, f)
}
ContextualParseError::InvalidCounterStyleWithoutSymbols(ref system) => {
write!(f, "Invalid @counter-style rule: 'system: {}' without 'symbols'", system)
}
ContextualParseError::InvalidCounterStyleNotEnoughSymbols(ref system) => {
write!(f, "Invalid @counter-style rule: 'system: {}' less than two 'symbols'", system)
}
ContextualParseError::InvalidCounterStyleWithoutAdditiveSymbols => {
write!(f, "Invalid @counter-style rule: 'system: additive' without 'additive-symbols'")
}
ContextualParseError::InvalidCounterStyleExtendsWithSymbols => {
write!(f, "Invalid @counter-style rule: 'system: extends …' with 'symbols'")
}
ContextualParseError::InvalidCounterStyleExtendsWithAdditiveSymbols => {
write!(f, "Invalid @counter-style rule: 'system: extends …' with 'additive-symbols'")
}
ContextualParseError::InvalidMediaRule(media_rule, ref err) => {
write!(f, "Invalid media rule: {}, ", media_rule)?;
parse_error_to_str(err, f)
}
}
}
}
/// A generic trait for an error reporter.
pub trait ParseErrorReporter {
/// Called when the style engine detects an error.
///
/// Returns the current input being parsed, the source location it was
/// reported from, and a message.
fn report_error(&self,
url: &UrlExtraData,
location: SourceLocation,
error: ContextualParseError);
}
/// An error reporter that uses [the `log` crate](https://github.com/rust-lang-nursery/log)
/// at `info` level.
///
/// This logging is silent by default, and can be enabled with a `RUST_LOG=style=info`
/// environment variable.
/// (See [`env_logger`](https://rust-lang-nursery.github.io/log/env_logger/).)
pub struct RustLogReporter;
impl ParseErrorReporter for RustLogReporter {
fn report_error(&self,
url: &UrlExtraData,
location: SourceLocation,
error: ContextualParseError) {
if log_enabled!(log::LogLevel::Info) {
info!("Url:\t{}\n{}:{} {}", url.as_str(), location.line, location.column, error)
}
}
}
/// Error reporter which silently forgets errors
pub struct NullReporter;
impl ParseErrorReporter for NullReporter {
fn report_error(&self,
_url: &UrlExtraData,
_location: SourceLocation,
_error: ContextualParseError) {
// do nothing
}
}