diff --git a/base/include/android-base/logging.h b/base/include/android-base/logging.h
index 7f0801f6c..aea6ce601 100644
--- a/base/include/android-base/logging.h
+++ b/base/include/android-base/logging.h
@@ -487,21 +487,14 @@ namespace std {
 // Note: to print the pointer, use "<< static_cast<const void*>(string_pointer)" instead.
 // Note: a not-recommended alternative is to let Clang ignore the warning by adding
 //       -Wno-user-defined-warnings to CPPFLAGS.
-#ifdef __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wgcc-compat"
 #define OSTREAM_STRING_POINTER_USAGE_WARNING \
     __attribute__((diagnose_if(true, "Unexpected logging of string pointer", "warning")))
-#else
-#define OSTREAM_STRING_POINTER_USAGE_WARNING /* empty */
-#endif
 inline std::ostream& operator<<(std::ostream& stream, const std::string* string_pointer)
     OSTREAM_STRING_POINTER_USAGE_WARNING {
   return stream << static_cast<const void*>(string_pointer);
 }
-#ifdef __clang__
 #pragma clang diagnostic pop
-#endif
-#undef OSTREAM_STRING_POINTER_USAGE_WARNING
 
 }  // namespace std
diff --git a/base/include/android-base/macros.h b/base/include/android-base/macros.h
index 0c8eac03c..49cc0c980 100644
--- a/base/include/android-base/macros.h
+++ b/base/include/android-base/macros.h
@@ -170,17 +170,7 @@ void UNUSED(const T&...) {
 //
 //  In either case this macro has no effect on runtime behavior and performance
 //  of code.
-#if defined(__clang__) && defined(__has_warning)
-#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
 #define FALLTHROUGH_INTENDED [[clang::fallthrough]]  // NOLINT
-#endif
-#endif
-
-#ifndef FALLTHROUGH_INTENDED
-#define FALLTHROUGH_INTENDED \
-  do {                       \
-  } while (0)
-#endif
 
 // Current ABI string
 #if defined(__arm__)
diff --git a/base/include/android-base/parseint.h b/base/include/android-base/parseint.h
index 933d877fb..fc68d56b4 100644
--- a/base/include/android-base/parseint.h
+++ b/base/include/android-base/parseint.h
@@ -42,9 +42,7 @@ bool ParseUint(const char* s, T* out, T max = std::numeric_limits<T>::max(),
     const char* suffixes = "bkmgtpe";
     const char* suffix;
     if (!allow_suffixes || (suffix = strchr(suffixes, tolower(*end))) == nullptr) return false;
-#if __clang__  // TODO: win32 still builds with GCC :-(
     if (__builtin_mul_overflow(result, 1ULL << (10 * (suffix - suffixes)), &result)) return false;
-#endif
   }
   if (max < result) {
     return false;
diff --git a/base/include/android-base/thread_annotations.h b/base/include/android-base/thread_annotations.h
index d56e9355d..5c55e6300 100644
--- a/base/include/android-base/thread_annotations.h
+++ b/base/include/android-base/thread_annotations.h
@@ -16,11 +16,7 @@
 
 #pragma once
 
-#if defined(__SUPPORT_TS_ANNOTATION__) || defined(__clang__)
-#define THREAD_ANNOTATION_ATTRIBUTE__(x)   __attribute__((x))
-#else
-#define THREAD_ANNOTATION_ATTRIBUTE__(x)   // no-op
-#endif
+#define THREAD_ANNOTATION_ATTRIBUTE__(x) __attribute__((x))
 
 #define CAPABILITY(x) \
       THREAD_ANNOTATION_ATTRIBUTE__(capability(x))
diff --git a/base/include/android-base/unique_fd.h b/base/include/android-base/unique_fd.h
index d334e30ed..6cfcd3fb0 100644
--- a/base/include/android-base/unique_fd.h
+++ b/base/include/android-base/unique_fd.h
@@ -142,10 +142,4 @@ inline bool Socketpair(int type, unique_fd* left, unique_fd* right) {
 
 template <typename T>
 int close(const android::base::unique_fd_impl<T>&)
-#if defined(__clang__)
-  __attribute__((__unavailable__(
-#else
-  __attribute__((__error__(
-#endif
-    "close called on unique_fd"
-  )));
+    __attribute__((__unavailable__("close called on unique_fd")));