diff --git a/src/kudu/client/schema.cc b/src/kudu/client/schema.cc
index 203f360..1acb290 100644
--- a/src/kudu/client/schema.cc
+++ b/src/kudu/client/schema.cc
@@ -228,7 +228,6 @@
 Status KuduColumnStorageAttributes::StringToEncodingType(
     const string& encoding,
     KuduColumnStorageAttributes::EncodingType* type) {
-  Status s;
   string encoding_uc;
   ToUpperCase(encoding, &encoding_uc);
   if (encoding_uc == "AUTO_ENCODING") {
@@ -246,16 +245,15 @@
   } else if (encoding_uc == "GROUP_VARINT") {
     *type = KuduColumnStorageAttributes::GROUP_VARINT;
   } else {
-    s = Status::InvalidArgument(Substitute(
+    return Status::InvalidArgument(Substitute(
         "encoding type $0 is not supported", encoding));
   }
-  return s;
+  return Status::OK();
 }
 
 Status KuduColumnStorageAttributes::StringToCompressionType(
     const string& compression,
     KuduColumnStorageAttributes::CompressionType* type) {
-  Status s;
   string compression_uc;
   ToUpperCase(compression, &compression_uc);
   if (compression_uc == "DEFAULT_COMPRESSION") {
@@ -269,10 +267,10 @@
   } else if (compression_uc == "ZLIB") {
     *type = KuduColumnStorageAttributes::ZLIB;
   } else {
-    s = Status::InvalidArgument(Substitute(
+    return Status::InvalidArgument(Substitute(
         "compression type $0 is not supported", compression));
   }
-  return s;
+  return Status::OK();
 }
 
 ////////////////////////////////////////////////////////////
@@ -711,7 +709,6 @@
 
  Status KuduColumnSchema::StringToDataType(
       const string& type_str, KuduColumnSchema::DataType* type) {
-  Status s;
   string type_uc;
   ToUpperCase(type_str, &type_uc);
   if (type_uc == "INT8") {
@@ -741,10 +738,10 @@
   } else if (type_uc == "DATE") {
     *type = DATE;
   } else {
-    s = Status::InvalidArgument(Substitute(
+    return Status::InvalidArgument(Substitute(
         "data type $0 is not supported", type_str));
   }
-  return s;
+  return Status::OK();
 }
 
 KuduColumnSchema::KuduColumnSchema(const string &name,
@@ -843,8 +840,11 @@
   KuduColumnStorageAttributes::StringToCompressionType(
       kudu::CompressionType_Name(storage_attributes.compression),
       &compression_type);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   return KuduColumnStorageAttributes(encoding_type, compression_type,
                                      storage_attributes.cfile_block_size);
+#pragma GCC diagnostic pop
 }
 
 const string& KuduColumnSchema::comment() const {
diff --git a/src/kudu/gutil/stl_util.h b/src/kudu/gutil/stl_util.h
index ae9df29..2eeb628 100644
--- a/src/kudu/gutil/stl_util.h
+++ b/src/kudu/gutil/stl_util.h
@@ -25,13 +25,12 @@
 // and Google friendly API.
 //
 
-#ifndef UTIL_GTL_STL_UTIL_H_
-#define UTIL_GTL_STL_UTIL_H_
+#pragma once
 
-#include <stddef.h>
-#include <string.h>  // for memcpy
 #include <algorithm>
 #include <cassert>
+#include <cstddef>
+#include <cstring>  // for memcpy
 #include <deque>
 #include <functional>
 #include <iterator>
@@ -309,7 +308,7 @@
 # ifdef NDEBUG
   return &*v->begin();
 # else
-  return v->empty() ? NULL : &*v->begin();
+  return v->empty() ? nullptr : &*v->begin();
 # endif
 }
 
@@ -318,7 +317,7 @@
 # ifdef NDEBUG
   return &*v->begin();
 # else
-  return v->empty() ? NULL : &*v->begin();
+  return v->empty() ? nullptr : &*v->begin();
 # endif
 }
 
@@ -336,7 +335,7 @@
 // implementations.
 inline char* string_as_array(std::string* str) {
   // DO NOT USE const_cast<char*>(str->data())! See the unittest for why.
-  return str->empty() ? NULL : &*str->begin();
+  return str->empty() ? nullptr : &*str->begin();
 }
 
 // These are methods that test two hash maps/sets for equality.  These exist
@@ -379,7 +378,7 @@
 // hash_set, or any other STL container which defines sensible begin(), end(),
 // and clear() methods.
 //
-// If container is NULL, this function is a no-op.
+// If container is nullptr, this function is a no-op.
 //
 // As an alternative to calling STLDeleteElements() directly, consider
 // ElementDeleter (defined below), which ensures that your container's elements
@@ -393,7 +392,7 @@
 
 // Given an STL container consisting of (key, value) pairs, STLDeleteValues
 // deletes all the "value" components and clears the container.  Does nothing
-// in the case it's given a NULL pointer.
+// in the case it's given a null pointer.
 template <class T>
 void STLDeleteValues(T *v) {
   if (!v) return;
@@ -829,8 +828,8 @@
   typedef typename Alloc::pointer pointer;
   typedef typename Alloc::size_type size_type;
 
-  STLCountingAllocator() : bytes_used_(NULL) { }
-  STLCountingAllocator(int64* b) : bytes_used_(b) {}  // TODO(user): explicit?
+  STLCountingAllocator() : bytes_used_(nullptr) { }
+  explicit STLCountingAllocator(int64* b) : bytes_used_(b) {}
 
   // Constructor used for rebinding
   template <class U>
@@ -839,15 +838,18 @@
         bytes_used_(x.bytes_used()) {
   }
 
-  pointer allocate(size_type n, std::allocator<void>::const_pointer hint = 0) {
-    assert(bytes_used_ != NULL);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+  pointer allocate(size_type n, std::allocator<void>::const_pointer hint = nullptr) {
+    assert(bytes_used_ != nullptr);
     *bytes_used_ += n * sizeof(T);
     return Alloc::allocate(n, hint);
   }
+#pragma GCC diagnostic pop
 
   void deallocate(pointer p, size_type n) {
     Alloc::deallocate(p, n);
-    assert(bytes_used_ != NULL);
+    assert(bytes_used_ != nullptr);
     *bytes_used_ -= n * sizeof(T);
   }
 
@@ -933,5 +935,3 @@
   }
   return false;
 }
-
-#endif  // UTIL_GTL_STL_UTIL_H_
diff --git a/src/kudu/security/gssapi.cc b/src/kudu/security/gssapi.cc
index 6797ec3..116b8f9 100644
--- a/src/kudu/security/gssapi.cc
+++ b/src/kudu/security/gssapi.cc
@@ -29,6 +29,13 @@
 
 using std::string;
 
+#if defined(__APPLE__)
+// Almost all functions in the krb5 API are marked as deprecated in favor
+// of GSS.framework in macOS.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif // #if defined(__APPLE__)
+
 namespace kudu {
 namespace gssapi {
 
@@ -162,3 +169,7 @@
 
 } // namespace gssapi
 } // namespace kudu
+
+#if defined(__APPLE__)
+#pragma GCC diagnostic pop
+#endif // #if defined(__APPLE__)
diff --git a/src/kudu/util/mem_tracker.h b/src/kudu/util/mem_tracker.h
index fc83363..fca7540 100644
--- a/src/kudu/util/mem_tracker.h
+++ b/src/kudu/util/mem_tracker.h
@@ -14,8 +14,7 @@
 // KIND, either express or implied.  See the License for the
 // specific language governing permissions and limitations
 // under the License.
-#ifndef KUDU_UTIL_MEM_TRACKER_H
-#define KUDU_UTIL_MEM_TRACKER_H
+#pragma once
 
 #include <cstdint>
 #include <list>
@@ -223,6 +222,8 @@
   ~MemTrackerAllocator() {
   }
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   pointer allocate(size_type n, const_pointer hint = 0) {
     // Ideally we'd use TryConsume() here to enforce the tracker's limit.
     // However, that means throwing bad_alloc if the limit is exceeded, and
@@ -241,6 +242,7 @@
   struct rebind {
     typedef MemTrackerAllocator<U, typename Alloc::template rebind<U>::other> other;
   };
+#pragma GCC diagnostic pop
 
   const std::shared_ptr<MemTracker>& mem_tracker() const { return mem_tracker_; }
 
@@ -277,5 +279,3 @@
 };
 
 } // namespace kudu
-
-#endif // KUDU_UTIL_MEM_TRACKER_H
diff --git a/src/kudu/util/memory/arena.h b/src/kudu/util/memory/arena.h
index 6eaa477..aec712e 100644
--- a/src/kudu/util/memory/arena.h
+++ b/src/kudu/util/memory/arena.h
@@ -251,9 +251,12 @@
 
   ~ArenaAllocator() { }
 
-  pointer allocate(size_type n, std::allocator<void>::const_pointer /*hint*/ = 0) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+  pointer allocate(size_type n, std::allocator<void>::const_pointer /*hint*/ = nullptr) {
     return reinterpret_cast<T*>(arena_->AllocateBytes(n * sizeof(T)));
   }
+#pragma GCC diagnostic pop
 
   void deallocate(pointer p, size_type n) {}