diff --git a/base/HidlInternal.cpp b/base/HidlInternal.cpp
index 5fae1c4..0ff52ad 100644
--- a/base/HidlInternal.cpp
+++ b/base/HidlInternal.cpp
@@ -96,7 +96,7 @@
         instrumentationLibPaths.push_back(HAL_LIBRARY_PATH_ODM);
     }
 
-    for (auto path : instrumentationLibPaths) {
+    for (const auto& path : instrumentationLibPaths) {
         DIR *dir = opendir(path.c_str());
         if (dir == 0) {
             LOG(WARNING) << path << " does not exist. ";
diff --git a/base/include/hidl/Status.h b/base/include/hidl/Status.h
index f812ebb..e2aab3f 100644
--- a/base/include/hidl/Status.h
+++ b/base/include/hidl/Status.h
@@ -143,7 +143,7 @@
         void assertOk() const;
     public:
         return_status() {}
-        return_status(Status s) : mStatus(s) {}
+        return_status(const Status& s) : mStatus(s) {}
 
         return_status(const return_status &) = delete;
         return_status &operator=(const return_status &) = delete;
@@ -240,7 +240,7 @@
 template<> class Return<void> : public details::return_status {
 public:
     Return() : details::return_status() {}
-    Return(Status s) : details::return_status(s) {}
+    Return(const Status& s) : details::return_status(s) {}
 
     // move-able.
     // precondition: "this" has checked status
diff --git a/test_main.cpp b/test_main.cpp
index b265607..90c8505 100644
--- a/test_main.cpp
+++ b/test_main.cpp
@@ -76,9 +76,9 @@
     EXPECT_STREQ(s6.c_str(), "s6");
     hidl_string s7 = std::string("s7"); // copy = from std::string
     EXPECT_STREQ(s7.c_str(), "s7");
-    hidl_string s8(s7); // copy constructor
+    hidl_string s8(s7); // copy constructor // NOLINT, test the copy constructor
     EXPECT_STREQ(s8.c_str(), "s7");
-    hidl_string s9 = s8; // copy =
+    hidl_string s9 = s8; // copy =  // NOLINT, test the copy operator
     EXPECT_STREQ(s9.c_str(), "s7");
     char myCString[20] = "myCString";
     s.setToExternal(&myCString[0], strlen(myCString));
@@ -154,14 +154,14 @@
     using android::hardware::hidl_memory;
 
     hidl_memory mem1 = hidl_memory(); // default constructor
-    hidl_memory mem2 = mem1; // copy constructor (nullptr)
+    hidl_memory mem2 = mem1; // copy constructor (nullptr), NOLINT
 
     EXPECT_EQ(nullptr, mem2.handle());
 
     native_handle_t* testHandle = native_handle_create(0 /* numInts */, 0 /* numFds */);
 
     hidl_memory mem3 = hidl_memory("foo", testHandle, 42 /* size */); // owns testHandle
-    hidl_memory mem4 = mem3; // copy constructor (regular handle)
+    hidl_memory mem4 = mem3; // copy constructor (regular handle), NOLINT
 
     EXPECT_EQ(mem3.name(), mem4.name());
     EXPECT_EQ(mem3.size(), mem4.size());
@@ -169,7 +169,7 @@
     EXPECT_NE(mem3.handle(), mem4.handle()); // check handle cloned
 
     hidl_memory mem5 = hidl_memory("foo", nullptr, 0); // hidl memory works with nullptr handle
-    hidl_memory mem6 = mem5;
+    hidl_memory mem6 = mem5; // NOLINT, test copying
     EXPECT_EQ(nullptr, mem5.handle());
     EXPECT_EQ(nullptr, mem6.handle());
 }
diff --git a/transport/ServiceManagement.cpp b/transport/ServiceManagement.cpp
index a404d10..feb1254 100644
--- a/transport/ServiceManagement.cpp
+++ b/transport/ServiceManagement.cpp
@@ -93,7 +93,7 @@
     }
     ifs >> cmdline;
 
-    size_t idx = cmdline.rfind("/");
+    size_t idx = cmdline.rfind('/');
     if (idx != std::string::npos) {
         cmdline = cmdline.substr(idx + 1);
     }
@@ -257,9 +257,10 @@
 }
 
 struct PassthroughServiceManager : IServiceManager1_1 {
-    static void openLibs(const std::string& fqName,
-            std::function<bool /* continue */(void* /* handle */,
-                const std::string& /* lib */, const std::string& /* sym */)> eachLib) {
+    static void openLibs(
+        const std::string& fqName,
+        const std::function<bool /* continue */ (void* /* handle */, const std::string& /* lib */,
+                                                 const std::string& /* sym */)>& eachLib) {
         //fqName looks like android.hardware.foo@1.0::IFoo
         size_t idx = fqName.find("::");