libafl_cc: -fsanitize=fuzzer is an alias to --libafl (#518)

* libafl_cc: -fsanitize=fuzzer is an alias to --libafl

* no link runtime

libafl_cc/build.rs

@@ -220,5 +220,9 @@ pub const CLANGXX_PATH: &str = \"clang++\";
         );
     }
 
+    cc::Build::new()
+        .file(src_dir.join("no-link-rt.c"))
+        .compile("no-link-rt");
+
     println!("cargo:rerun-if-changed=build.rs");
 }

libafl_cc/src/clang.rs

@@ -119,14 +119,26 @@ impl CompilerWrapper for ClangWrapper {
             linking = false;
         }
 
+        let mut suppress_linking = 0;
         for arg in &args[1..] {
             match arg.as_ref() {
                 "--libafl-no-link" => {
-                    linking = false;
+                    suppress_linking += 1;
                     self.has_libafl_arg = true;
                     continue;
                 }
                 "--libafl" => {
+                    suppress_linking += 1337;
+                    self.has_libafl_arg = true;
+                    continue;
+                }
+                "-fsanitize=fuzzer-no-link" => {
+                    suppress_linking += 1;
+                    self.has_libafl_arg = true;
+                    continue;
+                }
+                "-fsanitize=fuzzer" => {
+                    suppress_linking += 1337;
                     self.has_libafl_arg = true;
                     continue;
                 }
@@ -140,6 +152,17 @@ impl CompilerWrapper for ClangWrapper {
             };
             new_args.push(arg.as_ref().to_string());
         }
+        if linking && suppress_linking > 0 && suppress_linking < 1337 {
+            linking = false;
+            new_args.push(
+                PathBuf::from(env!("OUT_DIR"))
+                    .join(format!("{}no-link-rt.{}", LIB_PREFIX, LIB_EXT))
+                    .into_os_string()
+                    .into_string()
+                    .unwrap(),
+            );
+        }
+
         self.linking = linking;
 
         if self.optimize {

libafl_cc/src/no-link-rt.c

@@ -0,0 +1,36 @@
+#include <stdint.h>
+
+uint8_t* __afl_area_ptr;
+uint8_t* __afl_acc_memop_ptr;
+
+void __libafl_targets_cmplog_instructions(uintptr_t k, uint8_t shape, uint64_t arg1, uint64_t arg2) {
+    (void)k;
+    (void)shape;
+    (void)arg1;
+    (void)arg2;
+}
+
+void __cmplog_rtn_hook(uint8_t *ptr1, uint8_t *ptr2) {
+    (void)ptr1;
+    (void)ptr2;
+}
+
+void __cmplog_rtn_gcc_stdstring_cstring(uint8_t *stdstring, uint8_t *cstring) {
+    (void)stdstring;
+    (void)cstring;
+}
+
+void __cmplog_rtn_gcc_stdstring_stdstring(uint8_t *stdstring1, uint8_t *stdstring2) {
+    (void)stdstring1;
+    (void)stdstring2;
+}
+
+void __cmplog_rtn_llvm_stdstring_cstring(uint8_t *stdstring, uint8_t *cstring) {
+    (void)stdstring;
+    (void)cstring;
+}
+
+void __cmplog_rtn_llvm_stdstring_stdstring(uint8_t *stdstring1, uint8_t *stdstring2) {
+    (void)stdstring1;
+    (void)stdstring2;
+}