Separate symcc crate (#244)

* create a separate crate for symcc url and commit hash

also contains functions to checkout and build symcc from a build script

* fix dockerfile

* clippy

Cargo.toml

@@ -15,6 +15,7 @@ members = [
     "libafl_sugar",
     "libafl_tests",
     "libafl_concolic/symcc_runtime",
+    "libafl_concolic/symcc_libafl",
     "libafl_concolic/test/dump_constraints",
     "libafl_concolic/test/runtime_test",
 ]

Dockerfile

@@ -65,6 +65,9 @@ COPY scripts/dummy.rs libafl_concolic/test/runtime_test/src/lib.rs
 COPY libafl_concolic/symcc_runtime/Cargo.toml libafl_concolic/symcc_runtime/build.rs libafl_concolic/symcc_runtime/
 COPY scripts/dummy.rs libafl_concolic/symcc_runtime/src/lib.rs
 
+COPY libafl_concolic/symcc_libafl/Cargo.toml libafl_concolic/symcc_libafl/
+COPY scripts/dummy.rs libafl_concolic/symcc_libafl/src/lib.rs
+
 RUN cargo build && cargo build --release
 
 COPY scripts scripts
@@ -94,6 +97,7 @@ COPY libafl_frida/src libafl_frida/src
 RUN touch libafl_qemu/src/lib.rs
 COPY libafl_qemu/src libafl_qemu/src
 RUN touch libafl_frida/src/lib.rs
+COPY libafl_concolic/symcc_libafl libafl_concolic/symcc_libafl
 RUN cargo build && cargo build --release
 
 # Copy fuzzers over

fuzzers/libfuzzer_stb_image_concolic/fuzzer/Cargo.toml

@@ -24,3 +24,4 @@ cc = { version = "1.0", features = ["parallel"] }
 num_cpus = "1.0"
 cmake = "0.1"
 which = "4.1"
+symcc_libafl = {path = "../../../libafl_concolic/symcc_libafl"}

fuzzers/libfuzzer_stb_image_concolic/fuzzer/build.rs

@@ -92,48 +92,11 @@ fn main() {
     println!("cargo:rerun-if-changed=harness_symcc.c");
 }
 
-const SYMCC_REPO_URL: &str = "https://github.com/AFLplusplus/symcc.git";
-const SYMCC_REPO_COMMIT: &str = "45cde0269ae22aef4cca2e1fb98c3b24f7bb2984";
-
 fn clone_and_build_symcc(out_path: &Path) -> PathBuf {
     let repo_dir = out_path.join("libafl_symcc_src");
     if !repo_dir.exists() {
-        build_dep_check(&["git"]);
+        symcc_libafl::clone_symcc(&repo_dir);
-        let mut cmd = Command::new("git");
-        cmd.arg("clone").arg(SYMCC_REPO_URL).arg(&repo_dir);
-        let output = cmd.output().expect("failed to execute git clone");
-        if output.status.success() {
-            let mut cmd = Command::new("git");
-            cmd.arg("checkout")
-                .arg(SYMCC_REPO_COMMIT)
-                .current_dir(&repo_dir);
-            let output = cmd.output().expect("failed to execute git checkout");
-            if output.status.success() {
-            } else {
-                println!("failed to checkout symcc git repository commit:");
-                let mut stdout = stdout();
-                stdout
-                    .write_all(&output.stderr)
-                    .expect("failed to write git error message to stdout");
-                exit(1)
-            }
-        } else {
-            println!("failed to clone symcc git repository:");
-            let mut stdout = stdout();
-            stdout
-                .write_all(&output.stderr)
-                .expect("failed to write git error message to stdout");
-            exit(1)
-        }
     }
 
-    build_dep_check(&["cmake"]);
+    symcc_libafl::build_symcc(&repo_dir)
-
-    use cmake::Config;
-
-    Config::new(repo_dir)
-        .define("Z3_TRUST_SYSTEM_VERSION", "ON")
-        .no_build_target(true)
-        .build()
-        .join("build")
 }

libafl_concolic/symcc_libafl/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "symcc_libafl"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[features]
+default = ["build", "clone"]
+build = ["which", "cmake"] # common functionality to build symcc
+clone = ["which"] # common functionality to check out the symcc repo using git
+
+[dependencies]
+which = { version = "4.1", optional = true }
+cmake = { version = "0.1", optional = true }

libafl_concolic/symcc_libafl/src/lib.rs

@@ -0,0 +1,81 @@
+//! This is a 'meta-package' for libafl that exposes a consistent URL and commit hash for the
+//! [`SymCC` fork](https://github.com/AFLplusplus/symcc).
+
+/// The URL of the `LibAFL` `SymCC` fork.
+pub const SYMCC_REPO_URL: &str = "https://github.com/AFLplusplus/symcc.git";
+/// The commit of the `LibAFL` `SymCC` fork.
+pub const SYMCC_REPO_COMMIT: &str = "45cde0269ae22aef4cca2e1fb98c3b24f7bb2984";
+
+#[cfg(feature = "clone")]
+mod clone {
+    use std::{
+        io::{stdout, Write},
+        path::Path,
+        process::Command,
+    };
+
+    use which::which;
+
+    use crate::{SYMCC_REPO_COMMIT, SYMCC_REPO_URL};
+
+    /// Checks out the repository into the given directory with the given URL and commit hash.
+    /// Any errors will trigger a panic.
+    pub fn clone_symcc_at_version(path: &Path, url: &str, commit: &str) {
+        if which("git").is_err() {
+            panic!("ERROR: unable to find git. Git is required to download SymCC.");
+        }
+        let mut cmd = Command::new("git");
+        cmd.arg("clone").arg(url).arg(&path);
+        let output = cmd.output().expect("failed to execute git clone");
+        if output.status.success() {
+            let mut cmd = Command::new("git");
+            cmd.arg("checkout").arg(commit).current_dir(&path);
+            let output = cmd.output().expect("failed to execute git checkout");
+            if !output.status.success() {
+                println!("failed to checkout symcc git repository commit:");
+                let mut stdout = stdout();
+                stdout
+                    .write_all(&output.stderr)
+                    .expect("failed to write git error message to stdout");
+                panic!();
+            }
+        } else {
+            println!("failed to clone symcc git repository:");
+            let mut stdout = stdout();
+            stdout
+                .write_all(&output.stderr)
+                .expect("failed to write git error message to stdout");
+            panic!();
+        }
+    }
+
+    /// Checks out the repository into the given directory.
+    /// Any errors will trigger a panic.
+    pub fn clone_symcc(path: &Path) {
+        clone_symcc_at_version(path, SYMCC_REPO_URL, SYMCC_REPO_COMMIT);
+    }
+}
+
+#[cfg(feature = "clone")]
+pub use clone::clone_symcc;
+
+#[cfg(feature = "build")]
+mod build {
+    use std::path::{Path, PathBuf};
+
+    /// Builds `SymCC` at the given directory using [`cmake`](https://crates.io/crates/cmake).
+    /// Returns the build artifact directory.
+    #[must_use]
+    pub fn build_symcc(path: &Path) -> PathBuf {
+        use cmake::Config;
+
+        Config::new(path)
+            .define("Z3_TRUST_SYSTEM_VERSION", "ON")
+            .no_build_target(true)
+            .build()
+            .join("build")
+    }
+}
+
+#[cfg(feature = "build")]
+pub use build::build_symcc;

libafl_concolic/symcc_runtime/Cargo.toml

@@ -22,3 +22,4 @@ bindgen = "0.58"
 regex = "1"
 lazy_static = "1.4"
 which = "4.1"
+symcc_libafl = {path = "../symcc_libafl"}

libafl_concolic/symcc_runtime/build.rs

@@ -1,16 +1,14 @@
 use std::{
     env,
     fs::File,
-    io::{stdout, Write},
+    io::Write,
     path::{Path, PathBuf},
-    process::{exit, Command},
+    process::exit,
 };
 
 use lazy_static::lazy_static;
 use regex::{Regex, RegexBuilder};
-
+use symcc_libafl::clone_symcc;
-const SYMCC_REPO_URL: &str = "https://github.com/AFLplusplus/symcc.git";
-const SYMCC_REPO_COMMIT: &str = "45cde0269ae22aef4cca2e1fb98c3b24f7bb2984";
 
 const SYMCC_RUNTIME_FUNCTION_NAME_PREFIX: &str = "_cpp_";
 
@@ -108,38 +106,10 @@ fn write_cpp_function_export_macro(out_path: &Path, cpp_bindings: &bindgen::Bind
 
 fn checkout_symcc(out_path: &Path) -> PathBuf {
     let repo_dir = out_path.join("libafl_symcc_src");
-    if repo_dir.exists() {
+    if !repo_dir.exists() {
-        repo_dir
+        clone_symcc(&repo_dir);
-    } else {
-        build_dep_check(&["git"]);
-        let mut cmd = Command::new("git");
-        cmd.arg("clone").arg(SYMCC_REPO_URL).arg(&repo_dir);
-        let output = cmd.output().expect("failed to execute git clone");
-        if output.status.success() {
-            let mut cmd = Command::new("git");
-            cmd.arg("checkout")
-                .arg(SYMCC_REPO_COMMIT)
-                .current_dir(&repo_dir);
-            let output = cmd.output().expect("failed to execute git checkout");
-            if output.status.success() {
-                repo_dir
-            } else {
-                println!("failed to checkout symcc git repository commit:");
-                let mut stdout = stdout();
-                stdout
-                    .write_all(&output.stderr)
-                    .expect("failed to write git error message to stdout");
-                exit(1)
-            }
-        } else {
-            println!("failed to clone symcc git repository:");
-            let mut stdout = stdout();
-            stdout
-                .write_all(&output.stderr)
-                .expect("failed to write git error message to stdout");
-            exit(1)
-        }
     }
+    repo_dir
 }
 
 fn write_rust_runtime_macro_file(out_path: &Path, symcc_src_path: &Path) {