Update to the new arbitrary crate

Since it isn't released yet, we depend on the git version.

Author: fitzgen

Cargo.toml

@@ -13,7 +13,11 @@ edition = "2018"
 members = ["."]
 
 [dependencies]
-arbitrary = "0.2"
+# arbitrary = "0.3"
+arbitrary = { git = "https://github.com/rust-fuzz/arbitrary.git", rev = "8fa099d" }
 
 [build-dependencies]
 cc = "1.0"
+
+[features]
+arbitrary-derive = ["arbitrary/derive"]

example_arbitrary/Cargo.toml

@@ -8,5 +8,4 @@ edition = "2018"
 members = ["."]
 
 [dependencies]
-libfuzzer-sys = { path = ".." }
-arbitrary = "0.2"
+libfuzzer-sys = { path = "..", features = ["arbitrary-derive"] }

example_arbitrary/src/main.rs

@@ -1,9 +1,18 @@
 #![no_main]
 
-use libfuzzer_sys::fuzz_target;
+use libfuzzer_sys::{arbitrary, fuzz_target};
 
-fuzz_target!(|data: u16| {
-    if data == 0xba7 { // ba[nana]
-        panic!("success!");
+#[derive(arbitrary::Arbitrary, Debug)]
+struct Rgb {
+    r: u8,
+    g: u8,
+    b: u8,
+}
+
+fuzz_target!(|rgb: Rgb| {
+    if rgb.r < rgb.g {
+        if rgb.g < rgb.b {
+            panic!("success: r < g < b!");
+        }
     }
 });

src/lib.rs

@@ -129,14 +129,11 @@ macro_rules! fuzz_target {
     (|$data:ident: $dty: ty| $body:block) => {
         #[no_mangle]
         pub extern "C" fn rust_fuzzer_test_input(bytes: &[u8]) {
-            use libfuzzer_sys::arbitrary::{Arbitrary, RingBuffer};
+            use libfuzzer_sys::arbitrary::{Arbitrary, Unstructured};
 
-            let mut buf = match RingBuffer::new(bytes, bytes.len()) {
-                Ok(b) => b,
-                Err(_) => return,
-            };
+            let mut u = Unstructured::new(bytes);
 
-            let $data: $dty = match Arbitrary::arbitrary(&mut buf) {
+            let $data: $dty = match Arbitrary::arbitrary_take_rest(u) {
                 Ok(d) => d,
                 Err(_) => return,
             };