From f279f75a19172c9f8761c1fb9b5cbd1066175cc8 Mon Sep 17 00:00:00 2001
From: John Turner <jturner.usa@gmail.com>
Date: Mon, 8 Dec 2025 01:38:48 +0000
Subject: [PATCH] hookup atom parser fuzzer to read and write to stdin/stdout

---
 fuzz/atom/parser/fuzz.rs     | 110 ++++++++++++-----------------------
 fuzz/atom/parser/meson.build |   1 -
 2 files changed, 37 insertions(+), 74 deletions(-)

diff --git a/fuzz/atom/parser/fuzz.rs b/fuzz/atom/parser/fuzz.rs
index 9af41f2..db41eff 100644
--- a/fuzz/atom/parser/fuzz.rs
+++ b/fuzz/atom/parser/fuzz.rs
@@ -1,100 +1,64 @@
+#![allow(clippy::missing_safety_doc)]
+
 use core::slice;
 use gentoo_utils::{Parseable, atom::Atom};
-use mon::{Parser, ParserFinishedError, input::InputIter};
 use std::{
-    io::{BufRead, BufReader, Write},
-    process::{ChildStdin, ChildStdout, Command, Stdio},
+    io::{self, Write},
     sync::{LazyLock, Mutex},
 };
 
-struct PyProcess {
-    stdin: Mutex<ChildStdin>,
-    stdout: Mutex<BufReader<ChildStdout>>,
-    buffer: Mutex<String>,
+#[derive(Debug)]
+struct State {
+    input: io::Stdin,
+    output: io::Stdout,
 }
 
-#[allow(clippy::missing_safety_doc, clippy::needless_return)]
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn LLVMFuzzerTestOneInput(input: *const u8, len: usize) -> i32 {
-    static PY_PROCESS: LazyLock<PyProcess> = LazyLock::new(|| {
-        #[allow(clippy::zombie_processes)]
-        let mut proc = Command::new("atom.py")
-            .stdin(Stdio::piped())
-            .stdout(Stdio::piped())
-            .stderr(Stdio::inherit())
-            .spawn()
-            .expect("failed to spawn atom.py");
-
-        let stdin = Mutex::new(proc.stdin.take().unwrap());
-        let stdout = Mutex::new(BufReader::new(proc.stdout.take().unwrap()));
-
-        PyProcess {
-            stdin,
-            stdout,
-            buffer: Mutex::new(String::new()),
-        }
+    static PIPES: LazyLock<Mutex<State>> = LazyLock::new(|| {
+        Mutex::new(State {
+            input: io::stdin(),
+            output: io::stdout(),
+        })
     });
 
     let slice = unsafe { slice::from_raw_parts(input, len) };
+    let str = str::from_utf8(slice).expect("expected ascii input");
 
-    if slice.iter().any(|b| !b.is_ascii_graphic()) {
+    if str.chars().any(|c| !c.is_ascii_graphic()) {
         return -1;
     }
 
-    let str = match str::from_utf8(slice) {
-        Ok(str) => str,
-        Err(_) => return -1,
+    let mut state = PIPES.lock().unwrap();
+
+    writeln!(&mut state.output, "{str}").unwrap();
+
+    let mut buffer = String::new();
+
+    state.input.read_line(&mut buffer).unwrap();
+
+    let control = match buffer.as_str().trim() {
+        "0" => Ok(()),
+        "1" => Err(()),
+        other => panic!("unexpected input from pipes: {other}"),
     };
 
-    let atom = str.trim();
+    let gentoo_utils = Atom::parse(str);
 
-    let mut stdin = PY_PROCESS.stdin.lock().expect("failed to get stdin lock");
-
-    writeln!(&mut stdin, "{atom}").expect("failed to write to python stdin");
-
-    let mut stdout = PY_PROCESS.stdout.lock().expect("failed to get stdout lock");
-
-    let mut buffer = PY_PROCESS.buffer.lock().expect("failed to get buffer lock");
-
-    buffer.clear();
-
-    stdout
-        .read_line(&mut buffer)
-        .expect("failed to readline from python");
-
-    let portage_result = match buffer.as_str().trim() {
-        "0" => true,
-        "1" => false,
-        result => panic!("got unexpected result from python: {result}"),
-    };
-
-    let gentoo_utils_result = Atom::parser().parse_finished(InputIter::new(atom));
-
-    match (portage_result, gentoo_utils_result) {
-        (true, Ok(_)) => {
-            eprintln!("agreement that {atom} is valid");
+    match (control, gentoo_utils) {
+        (Ok(_), Ok(_)) => {
+            eprintln!("agreement that {str} is valid");
         }
-        (false, Err(_)) => {
-            eprintln!("agreement that {atom} is invalid");
+        (Err(_), Err(_)) => {
+            eprintln!("agreement that {str} is invalid");
         }
-        (true, Err(ParserFinishedError::Err(it) | ParserFinishedError::Unfinished(it))) => {
-            panic!("rejected valid atom: {atom}: {}", it.rest());
+        (Ok(_), Err(rest)) => {
+            panic!("disagreement on {str}\ncontrol:Ok\ngentoo-utils:Err({rest})");
         }
-        (false, Ok(atom))
-            if atom.usedeps().iter().any(|usedep| {
-                atom.usedeps()
-                    .iter()
-                    .filter(|u| usedep.flag() == u.flag())
-                    .count()
-                    > 1
-            }) =>
-        {
-            eprintln!("disagreement due to duplicates in usedeps");
-        }
-        (false, Ok(_)) => {
-            panic!("accpeted invalid atom: {atom}")
+        (Err(_), Ok(_)) => {
+            panic!("disagreement on {str}\ncontrol:Err\ngentoo-utils:Ok")
         }
     }
 
-    return 0;
+    0
 }
diff --git a/fuzz/atom/parser/meson.build b/fuzz/atom/parser/meson.build
index 9272a27..24ee1b7 100644
--- a/fuzz/atom/parser/meson.build
+++ b/fuzz/atom/parser/meson.build
@@ -20,7 +20,6 @@ fuzz_rs = static_library(
         '-Cllvm-args=-sanitizer-coverage-level=3',
         '-Cllvm-args=-sanitizer-coverage-inline-8bit-counters',
     ],
-    dependencies: [mon],
     link_with: [gentoo_utils],
 )