From 19133f5827288a56ec23bed3e3f074aa8a5bdd0b Mon Sep 17 00:00:00 2001
From: Andrea Fioraldi <andreafioraldi@gmail.com>
Date: Tue, 23 Mar 2021 12:17:28 +0100
Subject: [PATCH] clang wrapper skeleton

---
 libafl_cc/src/lib.rs | 130 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 127 insertions(+), 3 deletions(-)

diff --git a/libafl_cc/src/lib.rs b/libafl_cc/src/lib.rs
index 005323f7bb..7c92da60ee 100644
--- a/libafl_cc/src/lib.rs
+++ b/libafl_cc/src/lib.rs
@@ -1,9 +1,133 @@
-pub mod runtime;
+use std::{string::String, vec::Vec};
+
+#[derive(Debug)]
+pub enum Error {
+    InvalidArguments(String),
+    Unknown(String),
+}
+
+/// Wrap a compiler hijacking its arguments
+pub trait CompilerWrapper {
+    /// Set the wrapper arguments parsing a command line set of arguments
+    fn from_args<'a>(&'a mut self, args: Vec<String>) -> Result<&'a mut Self, Error>;
+
+    /// Add a compiler argument
+    fn add_arg<'a>(&'a mut self, arg: String) -> Result<&'a mut Self, Error>;
+
+    /// Run the compiler
+    fn compile(&mut self) -> Result<(), Error>;
+}
+
+/// Wrap Clang
+pub struct ClangWrapper {
+    optimize: bool,
+    wrapped_cc: String,
+    wrapped_cxx: String,
+
+    name: String,
+    is_cpp: bool,
+    linking: bool,
+    x_set: bool,
+    bit_mode: u32,
+
+    args: Vec<String>,
+}
+
+impl CompilerWrapper for ClangWrapper {
+    fn from_args<'a>(&'a mut self, args: Vec<String>) -> Result<&'a mut Self, Error> {
+        let mut new_args = vec![];
+        if args.len() < 1 {
+            return Err(Error::InvalidArguments(
+                "The number of arguments cannot be 0".into(),
+            ));
+        }
+
+        self.name = args[0].clone();
+        // Detect C++ compiler looking at the wrapper name
+        self.is_cpp = self.name.ends_with("++");
+        if self.is_cpp {
+            new_args.push(self.wrapped_cxx.clone());
+        } else {
+            new_args.push(self.wrapped_cc.clone());
+        }
+
+        // Sancov flag
+        // new_args.push("-fsanitize-coverage=trace-pc-guard".into());
+
+        let mut linking = true;
+        // Detect stray -v calls from ./configure scripts.
+        if args.len() == 1 && args[1] == "-v" {
+            linking = false;
+        }
+
+        for arg in &args[1..] {
+            match arg.as_str() {
+                "-x" => self.x_set = true,
+                "-m32" => self.bit_mode = 32,
+                "-m64" => self.bit_mode = 64,
+                "-c" | "-S" | "-E" => linking = false,
+                "-shared" => linking = false, // TODO dynamic list?
+                "-Wl,-z,defs" | "-Wl,--no-undefined" => continue,
+                _ => (),
+            };
+            new_args.push(arg.clone());
+        }
+        self.linking = linking;
+
+        if self.optimize {
+            new_args.push("-g".into());
+            new_args.push("-O3".into());
+            new_args.push("-funroll-loops".into());
+        }
+
+        // Fuzzing define common among tools
+        new_args.push("-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION=1".into());
+
+        self.args = new_args;
+        Ok(self)
+    }
+
+    fn add_arg<'a>(&'a mut self, arg: String) -> Result<&'a mut Self, Error> {
+        self.args.push(arg);
+        Ok(self)
+    }
+
+    fn compile(&mut self) -> Result<(), Error> {
+        if self.linking {
+            if self.x_set {
+                self.args.push("-x".into());
+                self.args.push("none".into());
+            }
+        }
+
+        Ok(())
+    }
+}
+
+impl ClangWrapper {
+    pub fn new(wrapped_cc: &str, wrapped_cxx: &str) -> Self {
+        Self {
+            optimize: true,
+            wrapped_cc: wrapped_cc.into(),
+            wrapped_cxx: wrapped_cxx.into(),
+            name: "".into(),
+            is_cpp: false,
+            linking: false,
+            x_set: false,
+            bit_mode: 0,
+            args: vec![],
+        }
+    }
+}
 
 #[cfg(test)]
 mod tests {
     #[test]
-    fn it_works() {
-        assert_eq!(2 + 2, 4);
+    fn test_clang_version() {
+        ClangWrapper::new("clang", "clang++")
+            .from_args(vec!["my-clang", "-v"])
+            .unwrap()
+            .compile()
+            .unwrap();
     }
 }