ethers-rs/ethers-solc/src/sourcemap.rs

529 lines
16 KiB
Rust

use std::{fmt, fmt::Write, iter::Peekable, str::CharIndices};
type Spanned<Token, Loc, Error> = Result<(Token, Loc), Error>;
macro_rules! syntax_err {
($msg:expr) => {{
Err(SyntaxError::new($msg))
}};
($msg:expr, $($tt:tt)*) => {{
Err(SyntaxError::new(format!($msg, $($tt)*)))
}};
}
/// An error that can happen during source map parsing.
#[derive(Debug, Clone, thiserror::Error)]
#[error("{0}")]
pub struct SyntaxError(String);
impl SyntaxError {
pub fn new(s: impl Into<String>) -> Self {
SyntaxError(s.into())
}
}
#[derive(PartialEq, Eq)]
enum Token<'a> {
Number(&'a str),
Semicolon,
Colon,
/// `i` which represents an instruction that goes into a function
In,
/// `o` which represents an instruction that returns from a function
Out,
/// `-` regular jump
Regular,
}
impl<'a> fmt::Debug for Token<'a> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Token::Number(s) => write!(f, "NUMBER({s:?})"),
Token::Semicolon => write!(f, "SEMICOLON"),
Token::Colon => write!(f, "COLON"),
Token::In => write!(f, "JMP(i)"),
Token::Out => write!(f, "JMP(o)"),
Token::Regular => write!(f, "JMP(-)"),
}
}
}
impl<'a> fmt::Display for Token<'a> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Token::Number(_) => write!(f, "number"),
Token::Semicolon => write!(f, "`;`"),
Token::Colon => write!(f, "`:`"),
Token::In => write!(f, "jmp-in"),
Token::Out => write!(f, "jmp-out"),
Token::Regular => write!(f, "jmp"),
}
}
}
struct TokenStream<'input> {
input: &'input str,
chars: Peekable<CharIndices<'input>>,
}
impl<'input> TokenStream<'input> {
pub fn new(input: &'input str) -> TokenStream<'input> {
TokenStream { chars: input.char_indices().peekable(), input }
}
fn number(
&mut self,
start: usize,
mut end: usize,
) -> Option<Spanned<Token<'input>, usize, SyntaxError>> {
loop {
if let Some((_, ch)) = self.chars.peek().cloned() {
if !ch.is_ascii_digit() {
break
}
self.chars.next();
end += 1;
} else {
end = self.input.len();
break
}
}
Some(Ok((Token::Number(&self.input[start..end]), start)))
}
}
impl<'input> Iterator for TokenStream<'input> {
type Item = Spanned<Token<'input>, usize, SyntaxError>;
fn next(&mut self) -> Option<Self::Item> {
match self.chars.next()? {
(i, ';') => Some(Ok((Token::Semicolon, i))),
(i, ':') => Some(Ok((Token::Colon, i))),
(i, 'i') => Some(Ok((Token::In, i))),
(i, 'o') => Some(Ok((Token::Out, i))),
(start, '-') => match self.chars.peek() {
Some((_, ch)) if ch.is_ascii_digit() => {
self.chars.next();
self.number(start, start + 2)
}
_ => Some(Ok((Token::Regular, start))),
},
(start, ch) if ch.is_ascii_digit() => self.number(start, start + 1),
(i, c) => Some(syntax_err!("Unexpected input {} at {}", c, i)),
}
}
}
#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
pub enum Jump {
/// A jump instruction that goes into a function
In,
/// A jump represents an instruction that returns from a function
Out,
/// A regular jump instruction
Regular,
}
impl AsRef<str> for Jump {
fn as_ref(&self) -> &str {
match self {
Jump::In => "i",
Jump::Out => "o",
Jump::Regular => "-",
}
}
}
impl fmt::Display for Jump {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(self.as_ref())
}
}
/// Represents a whole source map as list of `SourceElement`s
///
/// See also <https://docs.soliditylang.org/en/latest/internals/source_mappings.html#source-mappings>
pub type SourceMap = Vec<SourceElement>;
/// Represents a single element in the source map
/// A solidity source map entry takes the following form
///
/// before 0.6.0
/// s:l:f:j
///
/// after 0.6.0
/// s:l:f:j:m
///
/// Where s is the byte-offset to the start of the range in the source file, l is the length of the
/// source range in bytes and f is the source index.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct SourceElement {
/// The byte-offset to the start of the range in the source file
pub offset: usize,
/// The length of the source range in bytes
pub length: usize,
/// the source index
///
/// Note: In the case of instructions that are not associated with any particular source file,
/// the source mapping assigns an integer identifier of -1. This may happen for bytecode
/// sections stemming from compiler-generated inline assembly statements.
/// This case is represented as a `None` value
pub index: Option<u32>,
/// Jump instruction
pub jump: Jump,
/// “modifier depth”. This depth is increased whenever the placeholder statement (_) is entered
/// in a modifier and decreased when it is left again.
pub modifier_depth: usize,
}
impl fmt::Display for SourceElement {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"{}:{}:{}:{}:{}",
self.offset,
self.length,
self.index.map(|i| i as i64).unwrap_or(-1),
self.jump,
self.modifier_depth
)
}
}
#[derive(Default)]
struct SourceElementBuilder {
pub offset: Option<usize>,
pub length: Option<usize>,
pub index: Option<Option<u32>>,
pub jump: Option<Jump>,
pub modifier_depth: Option<usize>,
}
impl fmt::Display for SourceElementBuilder {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if self.offset.is_none() &&
self.length.is_none() &&
self.index.is_none() &&
self.jump.is_none() &&
self.modifier_depth.is_none()
{
return Ok(())
}
if let Some(s) = self.offset {
if self.index == Some(None) {
f.write_str("-1")?;
} else {
s.fmt(f)?;
}
}
if self.length.is_none() &&
self.index.is_none() &&
self.jump.is_none() &&
self.modifier_depth.is_none()
{
return Ok(())
}
f.write_char(':')?;
if let Some(s) = self.length {
if self.index == Some(None) {
f.write_str("-1")?;
} else {
s.fmt(f)?;
}
}
if self.index.is_none() && self.jump.is_none() && self.modifier_depth.is_none() {
return Ok(())
}
f.write_char(':')?;
if let Some(s) = self.index {
let s = s.map(|s| s as i64).unwrap_or(-1);
s.fmt(f)?;
}
if self.jump.is_none() && self.modifier_depth.is_none() {
return Ok(())
}
f.write_char(':')?;
if let Some(s) = self.jump {
s.fmt(f)?;
}
if self.modifier_depth.is_none() {
return Ok(())
}
f.write_char(':')?;
if let Some(s) = self.modifier_depth {
if self.index == Some(None) {
f.write_str("-1")?;
} else {
s.fmt(f)?;
}
}
Ok(())
}
}
impl SourceElementBuilder {
fn finish(self, prev: Option<SourceElement>) -> Result<SourceElement, SyntaxError> {
let element = if let Some(prev) = prev {
SourceElement {
offset: self.offset.unwrap_or(prev.offset),
length: self.length.unwrap_or(prev.length),
index: self.index.unwrap_or(prev.index),
jump: self.jump.unwrap_or(prev.jump),
modifier_depth: self.modifier_depth.unwrap_or(prev.modifier_depth),
}
} else {
SourceElement {
offset: self.offset.ok_or_else(|| SyntaxError::new("No previous offset"))?,
length: self.length.ok_or_else(|| SyntaxError::new("No previous length"))?,
index: self.index.ok_or_else(|| SyntaxError::new("No previous index"))?,
jump: self.jump.ok_or_else(|| SyntaxError::new("No previous jump"))?,
modifier_depth: self.modifier_depth.unwrap_or_default(),
}
};
Ok(element)
}
fn set_jmp(&mut self, jmp: Jump, i: usize) -> Option<SyntaxError> {
if self.jump.is_some() {
return Some(SyntaxError::new(format!("Jump already set: {i}")))
}
self.jump = Some(jmp);
None
}
fn set_offset(&mut self, offset: usize, i: usize) -> Option<SyntaxError> {
if self.offset.is_some() {
return Some(SyntaxError::new(format!("Offset already set: {i}")))
}
self.offset = Some(offset);
None
}
fn set_length(&mut self, length: usize, i: usize) -> Option<SyntaxError> {
if self.length.is_some() {
return Some(SyntaxError::new(format!("Length already set: {i}")))
}
self.length = Some(length);
None
}
fn set_index(&mut self, index: Option<u32>, i: usize) -> Option<SyntaxError> {
if self.index.is_some() {
return Some(SyntaxError::new(format!("Index already set: {i}")))
}
self.index = Some(index);
None
}
fn set_modifier(&mut self, modifier_depth: usize, i: usize) -> Option<SyntaxError> {
if self.modifier_depth.is_some() {
return Some(SyntaxError::new(format!("Modifier depth already set: {i}")))
}
self.modifier_depth = Some(modifier_depth);
None
}
}
pub struct Parser<'input> {
stream: TokenStream<'input>,
last_element: Option<SourceElement>,
done: bool,
#[cfg(test)]
output: Option<&'input mut dyn Write>,
}
impl<'input> Parser<'input> {
pub fn new(input: &'input str) -> Self {
Self {
stream: TokenStream::new(input),
last_element: None,
done: false,
#[cfg(test)]
output: None,
}
}
}
macro_rules! parse_number {
($num:expr, $pos:expr) => {{
let num = match $num.parse::<i64>() {
Ok(num) => num,
Err(_) => {
return Some(syntax_err!(
"Expected {} to be a `{}` at {}",
$num,
stringify!($t),
$pos
))
}
};
match num {
i if i < -1 => {
return Some(syntax_err!("Unexpected negative identifier of `{}` at {}", i, $pos))
}
-1 => None,
i => Some(i as u32),
}
}};
}
macro_rules! bail_opt {
($opt:stmt) => {
if let Some(err) = { $opt } {
return Some(Err(err))
}
};
}
impl<'input> Iterator for Parser<'input> {
type Item = Result<SourceElement, SyntaxError>;
fn next(&mut self) -> Option<Self::Item> {
// start parsing at the offset state, `s`
let mut state = State::Offset;
let mut builder = SourceElementBuilder::default();
loop {
match self.stream.next() {
Some(Ok((token, pos))) => match token {
Token::Semicolon => break,
Token::Number(num) => match state {
State::Offset => {
bail_opt!(builder.set_offset(
parse_number!(num, pos).unwrap_or_default() as usize,
pos
))
}
State::Length => {
bail_opt!(builder.set_length(
parse_number!(num, pos).unwrap_or_default() as usize,
pos
))
}
State::Index => {
bail_opt!(builder.set_index(parse_number!(num, pos), pos))
}
State::Modifier => {
bail_opt!(builder.set_modifier(
parse_number!(num, pos).unwrap_or_default() as usize,
pos
))
}
State::Jmp => {
return Some(syntax_err!("Expected Jump found number at {}", pos))
}
},
Token::Colon => {
bail_opt!(state.advance(pos))
}
Token::In => {
bail_opt!(builder.set_jmp(Jump::In, pos))
}
Token::Out => {
bail_opt!(builder.set_jmp(Jump::Out, pos))
}
Token::Regular => {
bail_opt!(builder.set_jmp(Jump::Regular, pos))
}
},
Some(Err(err)) => return Some(Err(err)),
None => {
if self.done {
return None
}
self.done = true;
break
}
}
}
#[cfg(test)]
{
if let Some(out) = self.output.as_mut() {
if self.last_element.is_some() {
let _ = out.write_char(';');
}
let _ = out.write_str(&builder.to_string());
}
}
let element = match builder.finish(self.last_element.take()) {
Ok(element) => {
self.last_element = Some(element.clone());
Ok(element)
}
Err(err) => Err(err),
};
Some(element)
}
}
/// State machine to keep track of separating `:`
#[derive(Clone, PartialEq, Eq, Copy)]
enum State {
// s
Offset,
// l
Length,
// f
Index,
// j
Jmp,
// m
Modifier,
}
impl State {
fn advance(&mut self, i: usize) -> Option<SyntaxError> {
match self {
State::Offset => *self = State::Length,
State::Length => *self = State::Index,
State::Index => *self = State::Jmp,
State::Jmp => *self = State::Modifier,
State::Modifier => return Some(SyntaxError::new(format!("unexpected colon at {i}"))),
}
None
}
}
/// Parses a source map
pub fn parse(input: &str) -> Result<SourceMap, SyntaxError> {
Parser::new(input).collect()
}
#[cfg(test)]
mod tests {
use super::*;
#[allow(unused)]
fn tokenize(s: &str) -> Vec<Spanned<Token, usize, SyntaxError>> {
TokenStream::new(s).collect()
}
#[test]
fn can_parse_source_maps() {
// all source maps from the compiler output test data
let source_maps = include_str!("../test-data/out-source-maps.txt");
for (line, s) in source_maps.lines().enumerate() {
parse(s).unwrap_or_else(|_| panic!("Failed to parse line {}", line));
}
}
#[test]
fn can_parse_foundry_cheatcodes_sol_maps() {
let s = include_str!("../test-data/cheatcodes.sol-sourcemap.txt");
let mut out = String::new();
let mut parser = Parser::new(s);
parser.output = Some(&mut out);
let _map = parser.collect::<Result<SourceMap, _>>().unwrap();
assert_eq!(out, s);
}
}