Differential executor, diff feedback, stdio observers for command exe…

…cutor (#521)

* started diff fuzzer

* finished DifferentialExecutor

* adapt builder, more diff fuzz infra

* diff eq feedback

* stdout observer started:

* stdio observers

* stdio observers

* no_std, fixes

* no_std tests

libafl/src/bolts/fs.rs

@@ -12,7 +12,7 @@ use std::os::unix::prelude::{AsRawFd, RawFd};
 use crate::Error;
 
 /// The default filename to use to deliver testcases to the target
-pub const DEFAULT_OUTFILE: &str = ".cur_input";
+pub const OUTFILE_STD: &str = ".cur_input";
 
 /// Creates a `.{file_name}.tmp` file, and writes all bytes to it.
 /// After all bytes have been written, the tmp-file is moved to it's original `path`.
@@ -55,6 +55,14 @@ pub struct OutFile {
     pub file: File,
 }
 
+impl Eq for OutFile {}
+
+impl PartialEq for OutFile {
+    fn eq(&self, other: &Self) -> bool {
+        self.path == other.path
+    }
+}
+
 impl Clone for OutFile {
     fn clone(&self) -> Self {
         Self {

libafl/src/bolts/os/unix_signals.rs

@@ -290,7 +290,7 @@ pub fn ucontext() -> Result<ucontext_t, Error> {
     } else {
         #[cfg(not(feature = "std"))]
         unsafe {
-            libc::perror(b"Failed to get ucontext\n".as_ptr() as _)
+            libc::perror(b"Failed to get ucontext\n".as_ptr() as _);
         };
         #[cfg(not(feature = "std"))]
         return Err(Error::Unknown("Failed to get ucontex".into()));

libafl/src/executors/combined.rs

@@ -1,4 +1,5 @@
 //! A `CombinedExecutor` wraps a primary executor and a secondary one
+//! In comparison to the [`crate::executors::DiffExecutor`] it does not run the secondary executor in `run_target`.
 
 use crate::{
     executors::{Executor, ExitKind, HasObservers},