use std::collections::{HashMap, HashSet};
use std::env;
use std::fs;
use std::path::{Path, PathBuf};
fn main() {
let manifest_dir = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap());
println!("cargo:rerun-if-changed=src/ported");
println!("cargo:rerun-if-changed=tests/data/htop_c_fn_names.txt");
println!("cargo:rerun-if-changed=tests/data/fake_fn_allowlist.txt");
println!("cargo:rerun-if-changed=build.rs");
let ported_root = manifest_dir.join("src/ported");
let c_index_path = manifest_dir.join("tests/data/htop_c_fn_names.txt");
let allowlist_path = manifest_dir.join("tests/data/fake_fn_allowlist.txt");
if !ported_root.exists() || !c_index_path.exists() {
return;
}
let c_names = match load_c_fn_index(&c_index_path) {
Ok(n) => n,
Err(e) => {
println!(
"cargo:warning=port drift: cannot read {} ({})",
c_index_path.display(),
e
);
return;
}
};
let allowlist: HashSet<String> = fs::read_to_string(&allowlist_path)
.unwrap_or_default()
.lines()
.map(|l| {
let l = match l.find('#') {
Some(i) => &l[..i],
None => l,
};
l.trim()
})
.filter(|l| !l.is_empty())
.map(|l| l.to_string())
.collect();
let mut rust_files: Vec<PathBuf> = Vec::new();
collect_rust_files(&ported_root, &mut rust_files);
let mut violations: Vec<String> = Vec::new();
for path in &rust_files {
let src = match fs::read_to_string(path) {
Ok(s) => s,
Err(_) => continue,
};
let rel = path
.strip_prefix(&manifest_dir)
.unwrap_or(path)
.display()
.to_string();
for (name, lineno) in collect_free_fns(&src) {
if !allowlist.contains(&name) && !c_names.contains_key(&name) {
violations.push(format!(
" {}:{} fn {} — no C counterpart in htop source",
rel, lineno, name,
));
}
}
}
if !violations.is_empty() {
violations.sort();
for v in &violations {
println!("cargo:warning={}", v.trim());
}
panic!(
"\n\
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n\
src/ported/ IS A PORT — NO NEW FUNCTIONS ALLOWED\n\
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n\n\
Every `pub fn` / `fn` under src/ported/ MUST be a faithful\n\
port of a function that exists in htop's upstream C source\n\
(~/forkedRepos/htop, snapshotted at\n\
tests/data/htop_c_fn_names.txt). Rust-original helpers,\n\
refactored extractions, convenience wrappers, and\n\
ad-hoc abstractions DO NOT BELONG HERE — they create\n\
drift between the port and the spec.\n\n\
{} fn(s) violate this rule:\n\n\
{}\n\n\
To fix:\n\n\
1. Preferred: inline the body at every call site\n\
(it isn't a real port, it shouldn't be a function).\n\
2. Or: rename to match the actual C function it ports.\n\
Cite <File>.c:<line> in the doc comment.\n\
3. Last resort: add the name to\n\
tests/data/fake_fn_allowlist.txt with a comment\n\
explaining why no C analog exists (architectural\n\
Rust-only helpers like singleton accessors only).\n\n\
Enforced by build.rs on every `cargo build` / `cargo test`\n\
/ `cargo check` whenever src/ported/** changes. Cannot be\n\
bypassed by `cargo test --test X`.\n\
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n",
violations.len(),
violations.join("\n")
);
}
}
fn collect_rust_files(root: &Path, out: &mut Vec<PathBuf>) {
let entries = match fs::read_dir(root) {
Ok(e) => e,
Err(_) => return,
};
for ent in entries.flatten() {
let path = ent.path();
if path.is_dir() {
collect_rust_files(&path, out);
} else if path.extension().and_then(|s| s.to_str()) == Some("rs") {
out.push(path);
}
}
}
fn collect_free_fns(src: &str) -> Vec<(String, usize)> {
let mut fns: Vec<(String, usize)> = Vec::new();
let mut depth: i32 = 0;
let mut in_test_mod = false;
let mut test_mod_depth: i32 = 0;
let mut in_block_comment: i32 = 0;
for (lineno, line) in src.lines().enumerate() {
let lineno = lineno + 1;
let trimmed = line.trim_start();
if depth == 0 && (trimmed.starts_with("mod tests {") || trimmed.starts_with("mod test {")) {
in_test_mod = true;
test_mod_depth = depth + 1;
}
let bytes = line.as_bytes();
let mut i = 0;
let mut delta: i32 = 0;
while i < bytes.len() {
let b = bytes[i];
if in_block_comment > 0 {
if b == b'*' && i + 1 < bytes.len() && bytes[i + 1] == b'/' {
in_block_comment -= 1;
i += 2;
continue;
}
if b == b'/' && i + 1 < bytes.len() && bytes[i + 1] == b'*' {
in_block_comment += 1;
i += 2;
continue;
}
i += 1;
continue;
}
match b {
b'/' if i + 1 < bytes.len() && bytes[i + 1] == b'/' => break,
b'/' if i + 1 < bytes.len() && bytes[i + 1] == b'*' => {
in_block_comment += 1;
i += 2;
}
b'"' => {
i += 1;
while i < bytes.len() {
let c = bytes[i];
if c == b'\\' {
i += 2;
continue;
}
if c == b'"' {
i += 1;
break;
}
i += 1;
}
}
b'r' if i + 1 < bytes.len() && (bytes[i + 1] == b'"' || bytes[i + 1] == b'#') => {
let mut hashes = 0;
let mut j = i + 1;
while j < bytes.len() && bytes[j] == b'#' {
hashes += 1;
j += 1;
}
if j < bytes.len() && bytes[j] == b'"' {
i = j + 1;
loop {
if i >= bytes.len() {
break;
}
if bytes[i] == b'"' {
let mut closed = 0;
let mut k = i + 1;
while k < bytes.len() && bytes[k] == b'#' && closed < hashes {
closed += 1;
k += 1;
}
if closed >= hashes {
i = k;
break;
}
}
i += 1;
}
} else {
i += 1;
}
}
b'\'' => {
let mut j = i + 1;
let mut found_close = false;
let mut escape = false;
while j < bytes.len() && j - i < 12 {
if !escape && bytes[j] == b'\'' {
found_close = true;
break;
}
escape = bytes[j] == b'\\' && !escape;
j += 1;
}
if found_close {
i = j + 1;
} else {
i += 1;
while i < bytes.len()
&& (bytes[i].is_ascii_alphanumeric() || bytes[i] == b'_')
{
i += 1;
}
}
}
b'{' => {
delta += 1;
i += 1;
}
b'}' => {
delta -= 1;
i += 1;
}
_ => i += 1,
}
}
let pre_depth = depth;
depth += delta;
if in_test_mod && depth < test_mod_depth {
in_test_mod = false;
}
if in_test_mod {
continue;
}
if pre_depth != 0 {
continue;
}
let stripped = trimmed
.strip_prefix("pub(crate) ")
.or_else(|| trimmed.strip_prefix("pub(super) "))
.unwrap_or_else(|| trimmed.strip_prefix("pub ").unwrap_or(trimmed));
let stripped = stripped.strip_prefix("unsafe ").unwrap_or(stripped);
let stripped = stripped.strip_prefix("async ").unwrap_or(stripped);
let stripped = stripped.strip_prefix(r#"extern "C" "#).unwrap_or(stripped);
if let Some(rest) = stripped.strip_prefix("fn ") {
let name_end = rest
.find(|c: char| c == '(' || c == '<' || c.is_whitespace())
.unwrap_or(0);
if name_end > 0 {
let name = rest[..name_end].to_string();
if name.chars().all(|c| c.is_ascii_alphanumeric() || c == '_') {
fns.push((name, lineno));
}
}
}
}
fns
}
fn load_c_fn_index(path: &Path) -> Result<HashMap<String, HashSet<String>>, std::io::Error> {
let src = fs::read_to_string(path)?;
let mut index: HashMap<String, HashSet<String>> = HashMap::new();
for line in src.lines() {
let line = line.trim();
if line.is_empty() || line.starts_with('#') {
continue;
}
if let Some((file, name)) = line.split_once(':') {
index
.entry(name.to_string())
.or_default()
.insert(file.to_string());
}
}
Ok(index)
}