From ab6d77ce1b7068b6f78eed8ae4f8a44c2e607f71 Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@apple.com>
Date: Thu, 5 Oct 2023 09:28:22 -0400
Subject: [PATCH] Enable -Wundef by default on some platforms.

* Fixes https://github.com/project-chip/connectedhomeip/issues/29216
---
 build/config/compiler/BUILD.gn           |  1 +
 src/inet/InetInterface.cpp               |  6 +++---
 src/lib/support/CHIPArgParser.hpp        |  4 ++++
 src/lib/support/Pool.h                   | 10 +++++++---
 src/lib/support/UnitTestRegistration.cpp |  4 ++--
 5 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index c508d657b17ab2..457d3978222cc7 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -235,6 +235,7 @@ config("strict_warnings") {
   cflags = [
     "-Wextra",
     "-Wshadow",
+    "-Wundef",
     "-Wunreachable-code",
     "-Wvla",
     "-Wformat",
diff --git a/src/inet/InetInterface.cpp b/src/inet/InetInterface.cpp
index e1c14dcfde449f..4d30309752408e 100644
--- a/src/inet/InetInterface.cpp
+++ b/src/inet/InetInterface.cpp
@@ -502,7 +502,7 @@ void CloseIOCTLSocket()
     }
 }
 
-#if __ANDROID__
+#ifdef __ANDROID__
 
 static struct if_nameindex * backport_if_nameindex(void);
 static void backport_if_freenameindex(struct if_nameindex *);
@@ -648,7 +648,7 @@ InterfaceIterator::~InterfaceIterator()
 {
     if (mIntfArray != nullptr)
     {
-#if __ANDROID__
+#ifdef __ANDROID__
         backport_if_freenameindex(mIntfArray);
 #else
         if_freenameindex(mIntfArray);
@@ -666,7 +666,7 @@ bool InterfaceIterator::Next()
 {
     if (mIntfArray == nullptr)
     {
-#if __ANDROID__
+#ifdef __ANDROID__
         mIntfArray = backport_if_nameindex();
 #else
         mIntfArray = if_nameindex();
diff --git a/src/lib/support/CHIPArgParser.hpp b/src/lib/support/CHIPArgParser.hpp
index 2c16a03f3a9239..57c68e353f58c6 100644
--- a/src/lib/support/CHIPArgParser.hpp
+++ b/src/lib/support/CHIPArgParser.hpp
@@ -32,6 +32,10 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#ifndef CHIP_CONFIG_NON_POSIX_LONG_OPT
+#define CHIP_CONFIG_NON_POSIX_LONG_OPT 0
+#endif
+
 namespace chip {
 namespace ArgParser {
 
diff --git a/src/lib/support/Pool.h b/src/lib/support/Pool.h
index 72d1a1842b0e36..c2486f0c0e20b3 100644
--- a/src/lib/support/Pool.h
+++ b/src/lib/support/Pool.h
@@ -324,9 +324,13 @@ class HeapObjectPool : public internal::Statistics, public internal::PoolCommon<
 #ifdef __clang__
 #if __has_feature(address_sanitizer)
 #define __SANITIZE_ADDRESS__ 1
-#endif
-#endif
-#endif
+#else
+#define __SANITIZE_ADDRESS__ 0
+#endif // __has_feature(address_sanitizer)
+#else
+#define __SANITIZE_ADDRESS__ 0
+#endif // __clang__
+#endif // __SANITIZE_ADDRESS__
 #if __SANITIZE_ADDRESS__
         // Free all remaining objects so that ASAN can catch specific use-after-free cases.
         ReleaseAll();
diff --git a/src/lib/support/UnitTestRegistration.cpp b/src/lib/support/UnitTestRegistration.cpp
index e706bbc891d6a5..93ea135b85a9ca 100644
--- a/src/lib/support/UnitTestRegistration.cpp
+++ b/src/lib/support/UnitTestRegistration.cpp
@@ -32,7 +32,7 @@ typedef struct
 
 static test_suites_t gs_test_suites;
 
-#if __ZEPHYR__
+#ifdef __ZEPHYR__
 inline static bool AlreadyExists(UnitTestTriggerFunction tests)
 {
     for (uint32_t i = 0; i < gs_test_suites.num_test_suites; ++i)
@@ -50,7 +50,7 @@ CHIP_ERROR RegisterUnitTests(UnitTestTriggerFunction tests)
         return CHIP_ERROR_NO_MEMORY;
     }
 
-#if __ZEPHYR__
+#ifdef __ZEPHYR__
     // Not sure yet if it's a Zephyr bug or misconfiguration, but global constructors are called
     // twice on native_posix platform - by libc and by Zephyr's main thread initialization code.
     // This makes sure tests are not run twice for that reason.