MacOS Build (#197)

* macos build

* more fix

* fixed clang pass build

* fixes for libfuzzer link

* more explanation links

libafl_cc/build.rs

@@ -1,5 +1,13 @@
 use std::{env, fs::File, io::Write, path::Path, process::Command, str};
 
+fn dll_extension<'a>() -> &'a str {
+    match env::var("CARGO_CFG_TARGET_OS").unwrap().as_str() {
+        "windwos" => "dll",
+        "macos" | "ios" => "dylib",
+        _ => "so",
+    }
+}
+
 fn main() {
     let out_dir = env::var_os("OUT_DIR").unwrap();
     let out_dir = Path::new(&out_dir);
@@ -43,14 +51,24 @@ pub const CLANGXX_PATH: &str = {:?};
         let ldflags = str::from_utf8(&output.stdout).expect("Invalid llvm-config output");
 
         let cxxflags: Vec<&str> = cxxflags.trim().split_whitespace().collect();
-        let ldflags: Vec<&str> = ldflags.trim().split_whitespace().collect();
+        let mut ldflags: Vec<&str> = ldflags.trim().split_whitespace().collect();
+
+        match env::var("CARGO_CFG_TARGET_OS").unwrap().as_str() {
+            // Needed on macos.
+            // Explanation at https://github.com/banach-space/llvm-tutor/blob/787b09ed31ff7f0e7bdd42ae20547d27e2991512/lib/CMakeLists.txt#L59
+            "macos" | "ios" => {
+                ldflags.push("-undefined");
+                ldflags.push("dynamic_lookup");
+            }
+            _ => (),
+        };
 
         let _ = Command::new(llvm_bindir.join("clang++"))
             .args(&cxxflags)
             .arg(src_dir.join("cmplog-routines-pass.cc"))
             .args(&ldflags)
             .args(&["-fPIC", "-shared", "-o"])
-            .arg(out_dir.join("cmplog-routines-pass.so"))
+            .arg(out_dir.join(format!("cmplog-routines-pass.{}", dll_extension())))
             .status()
             .expect("Failed to compile cmplog-routines-pass.cc");
     } else {

libafl_cc/src/clang.rs

@@ -2,6 +2,7 @@
 
 use std::{
     convert::Into,
+    env,
     path::{Path, PathBuf},
     string::String,
     vec::Vec,
@@ -9,6 +10,16 @@ use std::{
 
 use crate::{CompilerWrapper, Error, LIB_EXT, LIB_PREFIX};
 
+fn dll_extension<'a>() -> &'a str {
+    if cfg!(target_os = "windows") {
+        "dll"
+    } else if cfg!(any(target_os = "ios", target_os = "macos")) {
+        "dylib"
+    } else {
+        "so"
+    }
+}
+
 include!(concat!(env!("OUT_DIR"), "/clang_constants.rs"));
 
 #[allow(clippy::upper_case_acronyms)]
@@ -21,7 +32,8 @@ impl LLVMPasses {
     #[must_use]
     pub fn path(&self) -> PathBuf {
         match self {
-            LLVMPasses::CmpLogRtn => PathBuf::from(env!("OUT_DIR")).join("cmplog-routines-pass.so"),
+            LLVMPasses::CmpLogRtn => PathBuf::from(env!("OUT_DIR"))
+                .join(format!("cmplog-routines-pass.{}", dll_extension())),
         }
     }
 }

libafl_targets/src/common.h

@@ -75,6 +75,8 @@
 
 #define EXT_FUNC_DEF(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
   EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)
+#define EXT_FUNC_IMPL(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
+  EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)
 
 #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)         \
   RETURN_TYPE (*NAME##Def) FUNC_SIG = NULL;                 \
@@ -83,14 +85,21 @@
 
 #if defined(__APPLE__)
   // TODO: Find a proper way to deal with weak fns on Apple!
+  // On Apple, weak_import and weak attrs behave differently to linux.
   #define EXT_FUNC_DEF(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
-    EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) { return 0; }
+    EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN) { return (RETURN_TYPE) 0; }
+
+  #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)      \
+  __attribute__((weak, visibility("default"))) RETURN_TYPE NAME FUNC_SIG { \
+      return (RETURN_TYPE) 0;                              \
+  }
+
+  #define EXT_FUNC_IMPL(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
+  __attribute__((weak, visibility("default"))) RETURN_TYPE NAME FUNC_SIG
 
-  #define EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)           \
-  RETURN_TYPE NAME FUNC_SIG __attribute__((weak_import))
 #else
 
-#define EXT_FUNC_DEF(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
+#define EXT_FUNC_IMPL(NAME, RETURN_TYPE, FUNC_SIG, WARN) \
   EXT_FUNC(NAME, RETURN_TYPE, FUNC_SIG, WARN)
 
 // Declare these symbols as weak to allow them to be optionally defined.

libafl_targets/src/libfuzzer_compatibility.c

@@ -3,19 +3,19 @@
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-parameter"
-EXT_FUNC_DEF(LLVMFuzzerInitialize, int, (int *argc, char ***argv), false);
+EXT_FUNC(LLVMFuzzerInitialize, int, (int *argc, char ***argv), false);
-EXT_FUNC_DEF(LLVMFuzzerCustomMutator, size_t,
+EXT_FUNC(LLVMFuzzerCustomMutator, size_t,
          (uint8_t *Data, size_t Size, size_t MaxSize, unsigned int Seed),
          false);
-EXT_FUNC_DEF(LLVMFuzzerCustomCrossOver, size_t,
+EXT_FUNC(LLVMFuzzerCustomCrossOver, size_t,
          (const uint8_t *Data1, size_t Size1,
           const uint8_t *Data2, size_t Size2,
           uint8_t *Out, size_t MaxOutSize, unsigned int Seed),
          false);
-EXT_FUNC_DEF(LLVMFuzzerTestOneInput, int, (uint8_t *Data, size_t Size), false);
+EXT_FUNC(LLVMFuzzerTestOneInput, int, (uint8_t *Data, size_t Size), false);
 
-void libafl_main();
+void libafl_main(void);
-EXT_FUNC(main, int, (int argc, char** argv), false) {
+EXT_FUNC_IMPL(main, int, (int argc, char** argv), false) {
   libafl_main();
   return 0;
 }