Remove dead code.

PiperOrigin-RevId: 588828678

src/google/protobuf/map.h

@@ -454,18 +454,6 @@ size_t SpaceUsedInValues(const Map* map) {
   return size;
 }
 
-// Multiply two numbers where overflow is expected.
-template <typename N>
-N MultiplyWithOverflow(N a, N b) {
-#if defined(PROTOBUF_HAS_BUILTIN_MUL_OVERFLOW)
-  N res;
-  (void)__builtin_mul_overflow(a, b, &res);
-  return res;
-#else
-  return a * b;
-#endif
-}
-
 inline size_t SpaceUsedInValues(const void*) { return 0; }
 
 class UntypedMapBase;

src/google/protobuf/port_def.inc

@@ -67,12 +67,6 @@
 // - MSVC: https://docs.microsoft.com/en-us/visualstudio/releases/2019/release-notes-history
 //         https://docs.microsoft.com/en-us/visualstudio/releasenotes/vs2017-relnotes-history
 
-// Portable fallback for Clang's __has_warning macro:
-#ifndef __has_warning
-#define __has_warning(x) 0
-#define PROTOBUF_has_warning_DEFINED_
-#endif
-
 // Portable PROTOBUF_BUILTIN_BSWAPxx definitions
 // Code must check for availability, e.g.: `defined(PROTOBUF_BUILTIN_BSWAP32)`
 #ifdef PROTOBUF_BUILTIN_BSWAP16
@@ -94,11 +88,6 @@
 #define PROTOBUF_BUILTIN_BSWAP64(x) __builtin_bswap64(x)
 #endif
 
-// Portable check for __builtin_mul_overflow.
-#if ABSL_HAVE_BUILTIN(__builtin_mul_overflow)
-#define PROTOBUF_HAS_BUILTIN_MUL_OVERFLOW 1
-#endif
-
 // Portable check for gcc-style atomic built-ins
 #if ABSL_HAVE_BUILTIN(__atomic_load_n)
 #define PROTOBUF_BUILTIN_ATOMIC 1
@@ -512,11 +501,6 @@ static_assert(PROTOBUF_ABSL_MIN(20230125, 3),
 #define PROTOBUF_ALIGNAS(byte_alignment) alignas(byte_alignment)
 #endif
 
-#ifdef PROTOBUF_FINAL
-#error PROTOBUF_FINAL was previously defined
-#endif
-#define PROTOBUF_FINAL final
-
 #ifdef PROTOBUF_THREAD_LOCAL
 #error PROTOBUF_THREAD_LOCAL was previously defined
 #endif
@@ -579,21 +563,6 @@ static_assert(PROTOBUF_ABSL_MIN(20230125, 3),
 #define PROTOBUF_ATTRIBUTE_NO_DESTROY
 #endif
 
-// Force clang to always emit complete debug info for a type.
-// Clang uses constructor homing to determine when to emit debug info for a
-// type. If the constructor of a type is never used, which can happen in some
-// cases where member variables are constructed in place for optimization
-// purposes (see b/208803175 for an example), the type will have incomplete
-// debug info unless this attribute is used.
-#ifdef PROTOBUF_ATTRIBUTE_STANDALONE_DEBUG
-#error PROTOBUF_ATTRIBUTE_STANDALONE_DEBUG was previously defined
-#endif
-#if ABSL_HAVE_CPP_ATTRIBUTE(clang::standalone_debug)
-#define PROTOBUF_ATTRIBUTE_STANDALONE_DEBUG [[clang::standalone_debug]]
-#else
-#define PROTOBUF_ATTRIBUTE_STANDALONE_DEBUG
-#endif
-
 // Protobuf extensions and reflection require registration of the protos linked
 // in the binary. Not until everything is registered does the runtime have a
 // complete view on all protos. When code is using reflection or extensions
@@ -1070,10 +1039,3 @@ namespace internal {
 #endif  // !NDEBUG
 #endif  // has_builtin(__builtin_assume)
 
-// We don't want code outside port_def doing complex testing, so
-// remove our portable condition test macros to nudge folks away from
-// using it themselves.
-#ifdef PROTOBUF_has_warning_DEFINED_
-#  undef __has_warning
-#  undef PROTOBUF_has_warning_DEFINED_
-#endif

src/google/protobuf/port_undef.inc

@@ -19,7 +19,6 @@
 #undef PROTOBUF_BUILTIN_BSWAP16
 #undef PROTOBUF_BUILTIN_BSWAP32
 #undef PROTOBUF_BUILTIN_BSWAP64
-#undef PROTOBUF_HAS_BUILTIN_MUL_OVERFLOW
 #undef PROTOBUF_BUILTIN_ATOMIC
 #undef PROTOBUF_GNUC_MIN
 #undef PROTOBUF_CLANG_MIN
@@ -58,7 +57,6 @@
 #undef PROTOBUF_EXPORT_TEMPLATE_DECLARE
 #undef PROTOBUF_EXPORT_TEMPLATE_DEFINE
 #undef PROTOBUF_ALIGNAS
-#undef PROTOBUF_FINAL
 #undef PROTOBUF_THREAD_LOCAL
 #undef PROTOBUF_CONSTINIT
 #undef PROTOBUF_CONSTEXPR
@@ -66,7 +64,6 @@
 #undef PROTOBUF_ATTRIBUTE_WEAK
 #undef PROTOBUF_HAVE_ATTRIBUTE_WEAK
 #undef PROTOBUF_ATTRIBUTE_NO_DESTROY
-#undef PROTOBUF_ATTRIBUTE_STANDALONE_DEBUG
 #undef PROTOBUF_ATTRIBUTE_INIT_PRIORITY1
 #undef PROTOBUF_ATTRIBUTE_INIT_PRIORITY2
 #undef PROTOBUF_PRAGMA_INIT_SEG