diff --git a/build/gen.py b/build/gen.py
index 26bce26..d2305c8 100755
--- a/build/gen.py
+++ b/build/gen.py
@@ -335,6 +335,9 @@
         '-fno-exceptions',
         '-fno-rtti',
         '-fdiagnostics-color',
+        '-Wall',
+        '-Wextra',
+        '-Wno-unused-parameter',
     ])
     cflags_cc.extend(['-std=c++17'])
 
diff --git a/src/base/files/file_util_posix.cc b/src/base/files/file_util_posix.cc
index 87a38dd..7054880 100644
--- a/src/base/files/file_util_posix.cc
+++ b/src/base/files/file_util_posix.cc
@@ -142,19 +142,7 @@
 }
 #endif  // defined(OS_LINUX) || defined(OS_AIX)
 
-bool AdvanceEnumeratorWithStat(FileEnumerator* traversal,
-                               FilePath* out_next_path,
-                               struct stat* out_next_stat) {
-  DCHECK(out_next_path);
-  DCHECK(out_next_stat);
-  *out_next_path = traversal->Next();
-  if (out_next_path->empty())
-    return false;
-
-  *out_next_stat = traversal->GetInfo().stat();
-  return true;
-}
-
+#if !defined(OS_MACOSX)
 bool CopyFileContents(File* infile, File* outfile) {
   static constexpr size_t kBufferSize = 32768;
   std::vector<char> buffer(kBufferSize);
@@ -181,7 +169,6 @@
   return false;
 }
 
-#if !defined(OS_MACOSX)
 // Appends |mode_char| to |mode| before the optional character set encoding; see
 // https://www.gnu.org/software/libc/manual/html_node/Opening-Streams.html for
 // details.
diff --git a/src/util/ticks.cc b/src/util/ticks.cc
index f26b5d8..121c719 100644
--- a/src/util/ticks.cc
+++ b/src/util/ticks.cc
@@ -33,7 +33,9 @@
 #error Port.
 #endif
 
+#if !defined(OS_MACOSX)
 constexpr uint64_t kNano = 1'000'000'000;
+#endif
 
 void Init() {
   DCHECK(!g_initialized);