use std::fmt::Write as _;
use std::fs::File;
use std::io::{BufRead, BufReader, BufWriter, Write};
use std::path::{Path, PathBuf};
use tiny_keccak::{Hasher, Sha3};
fn main() -> anyhow::Result<()> {
let out_dir = PathBuf::from(std::env::var_os("OUT_DIR").unwrap());
gen_phf(&out_dir);
const SOURCE: &str = "src/python.lalrpop";
println!("cargo:rerun-if-changed={SOURCE}");
let target;
let error;
#[cfg(feature = "lalrpop")]
{
target = out_dir.join("src/python.rs");
}
#[cfg(not(feature = "lalrpop"))]
{
target = PathBuf::from("src/python.rs");
error = "python.lalrpop and src/python.rs doesn't match. This is a rustpython-parser bug. Please report it unless you are editing rustpython-parser. Run `lalrpop src/python.lalrpop` to build parser again.";
}
let Some(message) = requires_lalrpop(SOURCE, &target) else {
return Ok(());
};
#[cfg(feature = "lalrpop")]
{
let Err(e) = try_lalrpop() else {
return Ok(());
};
error = e;
}
println!("cargo:warning={message}");
panic!("running lalrpop failed. {error:?}");
}
fn requires_lalrpop(source: &str, target: &Path) -> Option<String> {
let Ok(target) = File::open(target) else {
return Some("python.rs doesn't exist. regenerate.".to_owned());
};
let sha_prefix = "// sha3: ";
let sha3_line = if let Some(sha3_line) =
BufReader::with_capacity(128, target)
.lines()
.find_map(|line| {
let line = line.unwrap();
line.starts_with(sha_prefix).then_some(line)
}) {
sha3_line
} else {
return Some("python.rs doesn't include sha3 hash. regenerate.".to_owned());
};
let expected_sha3_str = sha3_line.strip_prefix(sha_prefix).unwrap();
let actual_sha3 = {
let mut hasher = Sha3::v256();
let mut f = BufReader::new(File::open(source).unwrap());
let mut line = String::new();
while f.read_line(&mut line).unwrap() != 0 {
if line.ends_with('\n') {
line.pop();
if line.ends_with('\r') {
line.pop();
}
}
hasher.update(line.as_bytes());
hasher.update(b"\n");
line.clear();
}
let mut hash = [0u8; 32];
hasher.finalize(&mut hash);
hash
};
let eq = sha_equal(expected_sha3_str, &actual_sha3);
if !eq {
let mut actual_sha3_str = String::new();
for byte in actual_sha3 {
write!(actual_sha3_str, "{byte:02x}").unwrap();
}
return Some(format!(
"python.rs hash expected: {expected_sha3_str} but actual: {actual_sha3_str}"
));
}
None
}
#[cfg(feature = "lalrpop")]
fn try_lalrpop() -> Result<(), Box<dyn std::error::Error>> {
lalrpop::Configuration::new()
.use_cargo_dir_conventions()
.set_in_dir(Path::new("."))
.process()
}
fn sha_equal(expected_sha3_str: &str, actual_sha3: &[u8; 32]) -> bool {
if expected_sha3_str.len() != 64 {
panic!("lalrpop version? hash bug is fixed in 0.19.8");
}
let mut expected_sha3 = [0u8; 32];
for (i, b) in expected_sha3.iter_mut().enumerate() {
*b = u8::from_str_radix(&expected_sha3_str[i * 2..][..2], 16).unwrap();
}
*actual_sha3 == expected_sha3
}
fn gen_phf(out_dir: &Path) {
let mut kwds = phf_codegen::Map::new();
let kwds = kwds
.entry("...", "Tok::Ellipsis")
.entry("False", "Tok::False")
.entry("None", "Tok::None")
.entry("True", "Tok::True")
.entry("and", "Tok::And")
.entry("as", "Tok::As")
.entry("assert", "Tok::Assert")
.entry("async", "Tok::Async")
.entry("await", "Tok::Await")
.entry("break", "Tok::Break")
.entry("case", "Tok::Case")
.entry("class", "Tok::Class")
.entry("continue", "Tok::Continue")
.entry("def", "Tok::Def")
.entry("del", "Tok::Del")
.entry("elif", "Tok::Elif")
.entry("else", "Tok::Else")
.entry("except", "Tok::Except")
.entry("finally", "Tok::Finally")
.entry("for", "Tok::For")
.entry("from", "Tok::From")
.entry("global", "Tok::Global")
.entry("if", "Tok::If")
.entry("import", "Tok::Import")
.entry("in", "Tok::In")
.entry("is", "Tok::Is")
.entry("lambda", "Tok::Lambda")
.entry("match", "Tok::Match")
.entry("nonlocal", "Tok::Nonlocal")
.entry("not", "Tok::Not")
.entry("or", "Tok::Or")
.entry("pass", "Tok::Pass")
.entry("raise", "Tok::Raise")
.entry("return", "Tok::Return")
.entry("try", "Tok::Try")
.entry("type", "Tok::Type")
.entry("while", "Tok::While")
.entry("with", "Tok::With")
.entry("yield", "Tok::Yield")
.build();
writeln!(
BufWriter::new(File::create(out_dir.join("keywords.rs")).unwrap()),
"{kwds}",
)
.unwrap();
}