Add features for building with asan and fuzzing

Signed-off-by: Victor Porof <victor.porof@gmail.com>

Cargo.toml

@@ -50,3 +50,9 @@ lmdb-rkv-sys = { path = "./lmdb-sys" }
 [dev-dependencies]
 rand = "0.4.6"
 tempdir = "0.3.7"
+
+[features]
+default = []
+with-clang = ["lmdb-rkv-sys/with-clang"]
+with-asan = ["lmdb-rkv-sys/with-asan"]
+with-fuzzer = ["lmdb-rkv-sys/with-fuzzer"]

lmdb-sys/Cargo.toml

@@ -33,6 +33,9 @@ bindgen = "0.51.0"
 
 [features]
 default = []
+with-clang = []
+with-asan = ["with-clang"]
+with-fuzzer = ["with-clang"]
 
 # These features configure the MDB_IDL_LOGN macro, which determines
 # the size of the free and dirty page lists (and thus the amount of memory

lmdb-sys/build.rs

@@ -39,14 +39,29 @@ fn main() {
     lmdb.push("liblmdb");
 
     if !pkg_config::find_library("liblmdb").is_ok() {
-        cc::Build::new()
+        let mut builder = cc::Build::new();
+
+        builder
             .define("MDB_IDL_LOGN", Some(MDB_IDL_LOGN.to_string().as_str()))
             .file(lmdb.join("mdb.c"))
             .file(lmdb.join("midl.c"))
             // https://github.com/mozilla/lmdb/blob/b7df2cac50fb41e8bd16aab4cc5fd167be9e032a/libraries/liblmdb/Makefile#L23
             .flag_if_supported("-Wno-unused-parameter")
             .flag_if_supported("-Wbad-function-cast")
-            .flag_if_supported("-Wuninitialized")
-            .compile("liblmdb.a")
+            .flag_if_supported("-Wuninitialized");
+
+        if env::var("CARGO_FEATURE_WITH_CLANG").is_ok() {
+            builder.compiler("clang");
+        }
+
+        if env::var("CARGO_FEATURE_WITH_ASAN").is_ok() {
+            builder.flag("-fsanitize=address");
+        }
+
+        if env::var("CARGO_FEATURE_WITH_FUZZER").is_ok() {
+            builder.flag("-fsanitize=fuzzer");
+        }
+
+        builder.compile("liblmdb.a")
     }
 }