From 44b69666dad7dc3d27f85449c425b25cb9100620 Mon Sep 17 00:00:00 2001
From: Elsa Granger <zeyugao@outlook.com>
Date: Wed, 15 Feb 2023 18:58:32 +0800
Subject: [PATCH] Fix fuzzbench build (#1004)

* Fix -z,defs handle

* Add libfuzzer_no_link_main option in libfuzzer

* Use libfuzzer_no_link_main for fuzzbench

* no_link_main feature

---------

Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com>
---
 fuzzers/fuzzbench/Cargo.toml      |  1 +
 fuzzers/fuzzbench_text/Cargo.toml |  1 +
 libafl_cc/src/clang.rs            |  6 ++++--
 libafl_targets/Cargo.toml         |  1 +
 libafl_targets/build.rs           | 10 +++++++---
 libafl_targets/src/libfuzzer.c    |  3 +++
 6 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/fuzzers/fuzzbench/Cargo.toml b/fuzzers/fuzzbench/Cargo.toml
index d5ded20ad0..2a1328e712 100644
--- a/fuzzers/fuzzbench/Cargo.toml
+++ b/fuzzers/fuzzbench/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 [features]
 default = ["std"]
 std = []
+no_link_main = ["libafl_targets/libfuzzer_no_link_main"]
 
 [profile.release]
 lto = true
diff --git a/fuzzers/fuzzbench_text/Cargo.toml b/fuzzers/fuzzbench_text/Cargo.toml
index 221dd7663e..3fa90ecfdb 100644
--- a/fuzzers/fuzzbench_text/Cargo.toml
+++ b/fuzzers/fuzzbench_text/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 [features]
 default = ["std"]
 std = []
+no_link_main = ["libafl_targets/libfuzzer_no_link_main"]
 
 [profile.release]
 lto = true
diff --git a/libafl_cc/src/clang.rs b/libafl_cc/src/clang.rs
index aed7307fbc..9ebacbee51 100644
--- a/libafl_cc/src/clang.rs
+++ b/libafl_cc/src/clang.rs
@@ -167,8 +167,10 @@ impl CompilerWrapper for ClangWrapper {
                     i += 1;
                     continue;
                 }
-                "-z" => {
-                    if i + 1 < args.len() && args[i + 1].as_ref() == "defs" {
+                "-z" | "-Wl,-z" => {
+                    if i + 1 < args.len()
+                        && (args[i + 1].as_ref() == "defs" || args[i + 1].as_ref() == "-Wl,defs")
+                    {
                         i += 2;
                         continue;
                     }
diff --git a/libafl_targets/Cargo.toml b/libafl_targets/Cargo.toml
index a4738d749b..c73d7b3010 100644
--- a/libafl_targets/Cargo.toml
+++ b/libafl_targets/Cargo.toml
@@ -16,6 +16,7 @@ categories = ["development-tools::testing", "emulators", "embedded", "os", "no-s
 default = ["std", "sanitizers_flags"]
 std = ["libafl/std"]
 libfuzzer = []
+libfuzzer_no_link_main = ["libfuzzer"]
 sanitizers_flags = []
 pointer_maps = []
 sancov_pcguard_edges = []
diff --git a/libafl_targets/build.rs b/libafl_targets/build.rs
index 1d41cbf5ae..b7583ad140 100644
--- a/libafl_targets/build.rs
+++ b/libafl_targets/build.rs
@@ -84,9 +84,13 @@ fn main() {
     {
         println!("cargo:rerun-if-changed=src/libfuzzer.c");
 
-        cc::Build::new()
-            .file(src_dir.join("libfuzzer.c"))
-            .compile("libfuzzer");
+        let mut libfuzzer = cc::Build::new();
+        libfuzzer.file(src_dir.join("libfuzzer.c"));
+
+        #[cfg(feature = "libfuzzer_no_link_main")]
+        libfuzzer.define("FUZZER_NO_LINK_MAIN", "1");
+
+        libfuzzer.compile("libfuzzer");
     }
 
     println!("cargo:rerun-if-changed=src/common.h");
diff --git a/libafl_targets/src/libfuzzer.c b/libafl_targets/src/libfuzzer.c
index 4de0be79b1..42c7a8cd4f 100644
--- a/libafl_targets/src/libfuzzer.c
+++ b/libafl_targets/src/libfuzzer.c
@@ -18,6 +18,8 @@ EXT_FUNC_IMPL(LLVMFuzzerTestOneInput, int, (uint8_t *Data, size_t Size), false)
 
 EXT_FUNC_IMPL(libafl_main, void, (void), false) {
 }
+
+#ifndef FUZZER_NO_LINK_MAIN
 EXT_FUNC_IMPL(main, int, (int argc, char** argv), false) {
   libafl_main();
   return 0;
@@ -30,6 +32,7 @@ int main(int argc, char** argv) {
    libafl_main();
 }
 #endif
+#endif
 
 #pragma GCC diagnostic pop