move llvm_config to build.rs only

cargo-afl/build.rs

@@ -67,7 +67,7 @@ fn main() {
 }
 
 fn build_afl(work_dir: &Path, base: Option<&Path>) {
-    let llvm_config = common::get_llvm_config();
+    let llvm_config = get_llvm_config();
 
     if cfg!(feature = "cmplog") {
         // Make sure we are on nightly for the -Z flags
@@ -140,6 +140,14 @@ fn copy_afl_llvm_plugins(work_dir: &Path, base: Option<&Path>) {
     }
 }
 
+fn get_llvm_config() -> String {
+    // Fetch the llvm version of the rust toolchain and set the LLVM_CONFIG environement variable to the same version
+    // This is needed to compile the llvm plugins (needed for cmplog) from afl with the right LLVM version
+    let version_meta = rustc_version::version_meta().unwrap();
+    let llvm_version = version_meta.llvm_version.unwrap().major.to_string();
+    format!("llvm-config-{llvm_version}")
+}
+
 #[cfg(unix)]
 mod sys {
     use std::fs::File;

cargo-afl/src/bin/cargo-afl.rs

@@ -321,16 +321,6 @@ where
             "cargo-afl must be compiled with nightly for the cmplog feature"
         );
 
-        let llvm_config = common::get_llvm_config();
-
-        // check if llvm tools are installed and with the good version for the plugin compilation
-        let mut command = Command::new(llvm_config.clone());
-        command.args(["--version"]);
-        let status = command
-            .status()
-            .unwrap_or_else(|_| panic!("could not run {llvm_config} --version"));
-        assert!(status.success());
-
         rustflags.push_str(&format!(
             "-Z llvm-plugins={p}/cmplog-instructions-pass.so  \
             -Z llvm-plugins={p}/cmplog-routines-pass.so \

cargo-afl/src/common.rs

@@ -72,13 +72,3 @@ pub fn object_file_path(base: Option<&Path>) -> PathBuf {
 pub fn archive_file_path(base: Option<&Path>) -> PathBuf {
     afl_llvm_dir(base).join("libafl-llvm-rt.a")
 }
-
-#[allow(dead_code)]
-#[must_use]
-pub fn get_llvm_config() -> String {
-    // Fetch the llvm version of the rust toolchain and set the LLVM_CONFIG environement variable to the same version
-    // This is needed to compile the llvm plugins (needed for cmplog) from afl with the right LLVM version
-    let version_meta = rustc_version::version_meta().unwrap();
-    let llvm_version = version_meta.llvm_version.unwrap().major.to_string();
-    format!("llvm-config-{llvm_version}")
-}