From 6c2b158b38b55d79aee2627fc203ac6afc72583c Mon Sep 17 00:00:00 2001
From: Addison Crump <addison.crump@cispa.de>
Date: Tue, 6 Jun 2023 12:04:24 +0200
Subject: [PATCH] add libafl compatibility

---
 fuzz/Cargo.lock                             | 14 ++++++++++++--
 fuzz/Cargo.toml                             |  6 +++++-
 fuzz/README.md                              |  8 ++++++++
 fuzz/fuzz_targets/ruff_fix_validity.rs      |  3 +++
 fuzz/fuzz_targets/ruff_parse_idempotency.rs |  3 +++
 fuzz/fuzz_targets/ruff_parse_simple.rs      |  3 +++
 6 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/fuzz/Cargo.lock b/fuzz/Cargo.lock
index 8ea69673b6d799..6b6d05f1aeaa69 100644
--- a/fuzz/Cargo.lock
+++ b/fuzz/Cargo.lock
@@ -628,6 +628,16 @@ dependencies = [
  "static_assertions",
 ]
 
+[[package]]
+name = "libafl_libfuzzer"
+version = "0.1.0"
+source = "git+https://github.com/AFLplusplus/LibAFL.git?branch=libfuzzer#016cadf3b28f7acbbcd8e6dc80515cfab58e409b"
+dependencies = [
+ "cc",
+ "libfuzzer-sys",
+ "rustversion",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.144"
@@ -661,8 +671,7 @@ dependencies = [
 [[package]]
 name = "libfuzzer-sys"
 version = "0.4.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "beb09950ae85a0a94b27676cccf37da5ff13f27076aa1adbc6545dd0d0e1bd4e"
+source = "git+https://github.com/rust-fuzz/libfuzzer#1221c356e993b9f82d1ccd152f1c7636468758d2"
 dependencies = [
  "arbitrary",
  "cc",
@@ -1092,6 +1101,7 @@ name = "ruff-fuzz"
 version = "0.0.0"
 dependencies = [
  "arbitrary",
+ "libafl_libfuzzer",
  "libfuzzer-sys",
  "ruff",
  "ruff_python_ast",
diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index a26c8a2cfce62b..099102a7e0665f 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -9,14 +9,18 @@ publish = false
 edition = "2021"
 
 [features]
+default = ["libfuzzer"]
 full-idempotency = []
+libafl = ["libafl_libfuzzer"]
+libfuzzer = ["libfuzzer-sys/link_libfuzzer"]
 
 [package.metadata]
 cargo-fuzz = true
 
 [dependencies]
 arbitrary = { version = "1.3.0", features = ["derive"] }
-libfuzzer-sys = { version = "0.4.1" }
+libafl_libfuzzer = { git = "https://github.com/AFLplusplus/LibAFL.git", branch = "libfuzzer", optional = true }
+libfuzzer-sys = { git = "https://github.com/rust-fuzz/libfuzzer", default-features = false }
 ruff = { path = "../crates/ruff" }
 ruff_python_ast = { path = "../crates/ruff_python_ast" }
 ruff_python_formatter = { path = "../crates/ruff_python_formatter" }
diff --git a/fuzz/README.md b/fuzz/README.md
index 0446acc3820282..42907fd9f18e42 100644
--- a/fuzz/README.md
+++ b/fuzz/README.md
@@ -95,3 +95,11 @@ This fuzz harness checks that fixes applied by Ruff do not introduce new errors
 [`ruff::test::test_snippet`](../crates/ruff/src/test.rs) testing utility.
 It currently is only configured to use default settings, but may be extended in future versions to
 test non-default linter settings.
+
+## Experimental settings
+
+You can optionally use `--no-default-features --features libafl` to use the libafl fuzzer instead of
+libfuzzer.
+This fuzzer has experimental support, but can vastly improve fuzzer performance.
+If you are not already familiar with [LibAFL](https://github.com/AFLplusplus/LibAFL), this mode is
+not currently recommended.
diff --git a/fuzz/fuzz_targets/ruff_fix_validity.rs b/fuzz/fuzz_targets/ruff_fix_validity.rs
index 2b9764314e0887..750cda89b9487a 100644
--- a/fuzz/fuzz_targets/ruff_fix_validity.rs
+++ b/fuzz/fuzz_targets/ruff_fix_validity.rs
@@ -3,6 +3,9 @@
 
 #![no_main]
 
+#[cfg(feature = "libafl")]
+extern crate libafl_libfuzzer;
+
 use libfuzzer_sys::{fuzz_target, Corpus};
 use ruff::settings::Settings;
 use std::sync::OnceLock;
diff --git a/fuzz/fuzz_targets/ruff_parse_idempotency.rs b/fuzz/fuzz_targets/ruff_parse_idempotency.rs
index ac4387e3b43eaf..c09eee16c073b6 100644
--- a/fuzz/fuzz_targets/ruff_parse_idempotency.rs
+++ b/fuzz/fuzz_targets/ruff_parse_idempotency.rs
@@ -3,6 +3,9 @@
 
 #![no_main]
 
+#[cfg(feature = "libafl")]
+extern crate libafl_libfuzzer;
+
 use libfuzzer_sys::{fuzz_target, Corpus};
 use ruff_python_ast::source_code::round_trip;
 use similar::TextDiff;
diff --git a/fuzz/fuzz_targets/ruff_parse_simple.rs b/fuzz/fuzz_targets/ruff_parse_simple.rs
index e685f738575246..117ff38f12119c 100644
--- a/fuzz/fuzz_targets/ruff_parse_simple.rs
+++ b/fuzz/fuzz_targets/ruff_parse_simple.rs
@@ -3,6 +3,9 @@
 
 #![no_main]
 
+#[cfg(feature = "libafl")]
+extern crate libafl_libfuzzer;
+
 use libfuzzer_sys::{fuzz_target, Corpus};
 use ruff_python_ast::source_code::round_trip;