[libc++abi] Clean up visibility

Use the libc++abi visibility macros instead of pragmas or using
visibility attributes directly. Clean up redundant attributes on
definitions (where the declarations already have visibility attributes
applied, from either libc++ or libc++abi headers).

Introduce _LIBCXXABI_WEAK as a drive-by cleanup, which matches the
semantics of _LIBCPP_WEAK.

No functional change. Tested by building on Linux before and after this
change and verifying that the list of exported symbols is identical.

Differential Revision: https://reviews.llvm.org/D26949

llvm-svn: 296576

libcxxabi/include/__cxxabi_config.h

@@ -56,4 +56,10 @@
  #endif
 #endif
 
+#if defined(_WIN32)
+#define _LIBCXXABI_WEAK
+#else
+#define _LIBCXXABI_WEAK __attribute__((__weak__))
+#endif
+
 #endif // ____CXXABI_CONFIG_H

libcxxabi/src/abort_message.cpp

@@ -22,8 +22,6 @@ extern "C" void android_set_abort_message(const char* msg);
 #endif // __ANDROID_API__ >= 21
 #endif // __BIONIC__
 
-#pragma GCC visibility push(hidden)
-
 #ifdef __APPLE__
 #   if defined(__has_include) && __has_include(<CrashReporterClient.h>)
 #       define HAVE_CRASHREPORTERCLIENT_H
@@ -31,7 +29,6 @@ extern "C" void android_set_abort_message(const char* msg);
 #   endif
 #endif
 
-__attribute__((visibility("hidden"), noreturn))
 void abort_message(const char* format, ...)
 {
     // write message to stderr
@@ -79,5 +76,3 @@ void abort_message(const char* format, ...)
 
     abort();
 }
-
-#pragma GCC visibility pop

libcxxabi/src/abort_message.h

@@ -10,24 +10,18 @@
 #ifndef __ABORT_MESSAGE_H_
 #define __ABORT_MESSAGE_H_
 
-#include <stdio.h>
-
-#pragma GCC visibility push(hidden)
+#include "cxxabi.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-__attribute__((visibility("hidden"), noreturn))
-       void abort_message(const char* format, ...) 
-            __attribute__((format(printf, 1, 2)));
-
+_LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN void
+abort_message(const char *format, ...) __attribute__((format(printf, 1, 2)));
 
 #ifdef __cplusplus
 }
 #endif
 
-#pragma GCC visibility pop
-
 #endif
 

libcxxabi/src/cxa_exception.cpp

@@ -33,8 +33,6 @@
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(default)
-
 //  Utility routines
 static
 inline
@@ -139,7 +137,7 @@ extern "C" {
 //  object. Zero-fill the object. If memory can't be allocated, call
 //  std::terminate. Return a pointer to the memory to be used for the
 //  user's exception object.
-_LIBCXXABI_FUNC_VIS void *__cxa_allocate_exception(size_t thrown_size) throw() {
+void *__cxa_allocate_exception(size_t thrown_size) throw() {
     size_t actual_size = cxa_exception_size_from_exception_thrown_size(thrown_size);
     __cxa_exception *exception_header =
         static_cast<__cxa_exception *>(__malloc_with_fallback(actual_size));
@@ -151,7 +149,7 @@ _LIBCXXABI_FUNC_VIS void *__cxa_allocate_exception(size_t thrown_size) throw() {
 
 
 //  Free a __cxa_exception object allocated with __cxa_allocate_exception.
-_LIBCXXABI_FUNC_VIS void __cxa_free_exception(void *thrown_object) throw() {
+void __cxa_free_exception(void *thrown_object) throw() {
     __free_with_fallback(cxa_exception_from_thrown_object(thrown_object));
 }
 
@@ -202,7 +200,7 @@ handler, _Unwind_RaiseException may return. In that case, __cxa_throw
 will call terminate, assuming that there was no handler for the
 exception.
 */
-_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void
+void
 __cxa_throw(void *thrown_object, std::type_info *tinfo, void (*dest)(void *)) {
     __cxa_eh_globals *globals = __cxa_get_globals();
     __cxa_exception* exception_header = cxa_exception_from_thrown_object(thrown_object);
@@ -235,7 +233,6 @@ The adjusted pointer is computed by the personality routine during phase 1
 
   Requires:  exception is native
 */
-_LIBCXXABI_FUNC_VIS
 void *__cxa_get_exception_ptr(void *unwind_exception) throw() {
 #if _LIBCXXABI_ARM_EHABI
     return reinterpret_cast<void*>(
@@ -251,7 +248,6 @@ void *__cxa_get_exception_ptr(void *unwind_exception) throw() {
 The routine to be called before the cleanup.  This will save __cxa_exception in
 __cxa_eh_globals, so that __cxa_end_cleanup() can recover later.
 */
-_LIBCXXABI_FUNC_VIS
 bool __cxa_begin_cleanup(void *unwind_arg) throw() {
     _Unwind_Exception* unwind_exception = static_cast<_Unwind_Exception*>(unwind_arg);
     __cxa_eh_globals* globals = __cxa_get_globals();
@@ -423,7 +419,7 @@ For a foreign exception:
 * If it has been rethrown, there is nothing to do.
 * Otherwise delete the exception and pop the catch stack to empty.
 */
-_LIBCXXABI_FUNC_VIS void __cxa_end_catch() {
+void __cxa_end_catch() {
   static_assert(sizeof(__cxa_exception) == sizeof(__cxa_dependent_exception),
                 "sizeof(__cxa_exception) must be equal to "
                 "sizeof(__cxa_dependent_exception)");
@@ -500,7 +496,7 @@ _LIBCXXABI_FUNC_VIS void __cxa_end_catch() {
 // Note:  exception_header may be masquerading as a __cxa_dependent_exception
 //        and that's ok.  exceptionType is there too.
 //        However watch out for foreign exceptions.  Return null for them.
-_LIBCXXABI_FUNC_VIS std::type_info *__cxa_current_exception_type() {
+std::type_info *__cxa_current_exception_type() {
 //  get the current exception
     __cxa_eh_globals *globals = __cxa_get_globals_fast();
     if (NULL == globals)
@@ -525,7 +521,7 @@ If the exception is native:
   Note:  exception_header may be masquerading as a __cxa_dependent_exception
          and that's ok.
 */
-_LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_rethrow() {
+void __cxa_rethrow() {
     __cxa_eh_globals* globals = __cxa_get_globals();
     __cxa_exception* exception_header = globals->caughtExceptions;
     if (NULL == exception_header)
@@ -570,7 +566,7 @@ _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_rethrow() {
 
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
-_LIBCXXABI_FUNC_VIS void
+void
 __cxa_increment_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
@@ -587,7 +583,7 @@ __cxa_increment_exception_refcount(void *thrown_object) throw() {
 
     Requires:  If thrown_object is not NULL, it is a native exception.
 */
-_LIBCXXABI_FUNC_VIS void
+void
 __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     if (thrown_object != NULL )
     {
@@ -611,7 +607,7 @@ __cxa_decrement_exception_refcount(void *thrown_object) throw() {
     been no exceptions thrown, ever, on this thread, we can return NULL without 
     the need to allocate the exception-handling globals.
 */
-_LIBCXXABI_FUNC_VIS void *__cxa_current_primary_exception() throw() {
+void *__cxa_current_primary_exception() throw() {
 //  get the current exception
     __cxa_eh_globals* globals = __cxa_get_globals_fast();
     if (NULL == globals)
@@ -697,6 +693,4 @@ __cxa_uncaught_exceptions() throw()
 
 }  // extern "C"
 
-#pragma GCC visibility pop
-
 }  // abi

libcxxabi/src/cxa_exception.hpp

@@ -20,13 +20,11 @@
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(hidden)
-
 static const uint64_t kOurExceptionClass          = 0x434C4E47432B2B00; // CLNGC++\0
 static const uint64_t kOurDependentExceptionClass = 0x434C4E47432B2B01; // CLNGC++\1
 static const uint64_t get_vendor_and_language     = 0xFFFFFFFFFFFFFF00; // mask for CLNGC++
 
-struct __cxa_exception {
+struct _LIBCXXABI_HIDDEN __cxa_exception {
 #if defined(__LP64__) || _LIBCXXABI_ARM_EHABI
     // This is a new field to support C++ 0x exception_ptr.
     // For binary compatibility it is at the start of this
@@ -69,7 +67,7 @@ struct __cxa_exception {
 // http://sourcery.mentor.com/archives/cxx-abi-dev/msg01924.html
 // The layout of this structure MUST match the layout of __cxa_exception, with
 // primaryException instead of referenceCount.
-struct __cxa_dependent_exception {
+struct _LIBCXXABI_HIDDEN __cxa_dependent_exception {
 #if defined(__LP64__) || _LIBCXXABI_ARM_EHABI
     void* primaryException;
 #endif
@@ -101,7 +99,7 @@ struct __cxa_dependent_exception {
     _Unwind_Exception unwindHeader;
 };
 
-struct __cxa_eh_globals {
+struct _LIBCXXABI_HIDDEN __cxa_eh_globals {
     __cxa_exception *   caughtExceptions;
     unsigned int        uncaughtExceptions;
 #if _LIBCXXABI_ARM_EHABI
@@ -109,16 +107,11 @@ struct __cxa_eh_globals {
 #endif
 };
 
-#pragma GCC visibility pop
-#pragma GCC visibility push(default)
+extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals      ();
+extern "C" _LIBCXXABI_FUNC_VIS __cxa_eh_globals * __cxa_get_globals_fast ();
 
-extern "C" __cxa_eh_globals * __cxa_get_globals      ();
-extern "C" __cxa_eh_globals * __cxa_get_globals_fast ();
-
-extern "C" void * __cxa_allocate_dependent_exception ();
-extern "C" void __cxa_free_dependent_exception (void * dependent_exception);
-
-#pragma GCC visibility pop
+extern "C" _LIBCXXABI_FUNC_VIS void * __cxa_allocate_dependent_exception ();
+extern "C" _LIBCXXABI_FUNC_VIS void __cxa_free_dependent_exception (void * dependent_exception);
 
 }  // namespace __cxxabiv1
 

libcxxabi/src/cxa_handlers.cpp

@@ -32,7 +32,6 @@ get_unexpected() _NOEXCEPT
 //  return __cxa_unexpected_handler.load(memory_order_acq);
 }
 
-__attribute__((visibility("hidden"), noreturn))
 void
 __unexpected(unexpected_handler func)
 {
@@ -57,7 +56,6 @@ get_terminate() _NOEXCEPT
 //  return __cxa_terminate_handler.load(memory_order_acq);
 }
 
-__attribute__((visibility("hidden"), noreturn))
 void
 __terminate(terminate_handler func) _NOEXCEPT
 {
@@ -105,7 +103,7 @@ terminate() _NOEXCEPT
 // In the future this will become:
 // std::atomic<std::new_handler>  __cxa_new_handler(0);
 extern "C" {
-_LIBCXXABI_DATA_VIS new_handler __cxa_new_handler = 0;
+new_handler __cxa_new_handler = 0;
 }
 
 new_handler

libcxxabi/src/cxa_handlers.hpp

@@ -20,11 +20,11 @@
 namespace std
 {
 
-__attribute__((visibility("hidden"), noreturn))
+_LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN
 void
 __unexpected(unexpected_handler func);
 
-__attribute__((visibility("hidden"), noreturn))
+_LIBCXXABI_HIDDEN _LIBCXXABI_NORETURN
 void
 __terminate(terminate_handler func) _NOEXCEPT;
 

libcxxabi/src/cxa_new_delete.cpp

@@ -11,6 +11,7 @@
 
 #define _LIBCPP_BUILDING_NEW
 
+#include "__cxxabi_config.h"
 #include <new>
 #include <cstdlib>
 
@@ -36,7 +37,7 @@
 * The loop terminates when an attempt to allocate the requested storage is
   successful or when a called new_handler function does not return.
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void *
 operator new(std::size_t size) _THROW_BAD_ALLOC
 {
@@ -70,7 +71,7 @@ http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2158.html
 Calls operator new(size). If the call returns normally, returns the result of
 that call. Otherwise, returns a null pointer.
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void*
 operator new(size_t size, const std::nothrow_t&) _NOEXCEPT
 {
@@ -94,7 +95,7 @@ operator new(size_t size, const std::nothrow_t&) _NOEXCEPT
 
 Returns operator new(size).
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void*
 operator new[](size_t size) _THROW_BAD_ALLOC
 {
@@ -107,7 +108,7 @@ operator new[](size_t size) _THROW_BAD_ALLOC
 Calls operator new[](size). If the call returns normally, returns the result
 of that call. Otherwise, returns a null pointer.
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void*
 operator new[](size_t size, const std::nothrow_t&) _NOEXCEPT
 {
@@ -132,7 +133,7 @@ operator new[](size_t size, const std::nothrow_t&) _NOEXCEPT
 If ptr is null, does nothing. Otherwise, reclaims the storage allocated by the
 earlier call to operator new.
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void
 operator delete(void* ptr) _NOEXCEPT
 {
@@ -145,7 +146,7 @@ operator delete(void* ptr) _NOEXCEPT
 
 calls operator delete(ptr)
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void
 operator delete(void* ptr, const std::nothrow_t&) _NOEXCEPT
 {
@@ -157,7 +158,7 @@ operator delete(void* ptr, const std::nothrow_t&) _NOEXCEPT
 
 Calls operator delete(ptr)
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void
 operator delete[] (void* ptr) _NOEXCEPT
 {
@@ -169,7 +170,7 @@ operator delete[] (void* ptr) _NOEXCEPT
 
 calls operator delete[](ptr)
 */
-__attribute__((__weak__, __visibility__("default")))
+_LIBCXXABI_WEAK
 void
 operator delete[] (void* ptr, const std::nothrow_t&) _NOEXCEPT
 {

libcxxabi/src/cxa_noexception.cpp

@@ -22,8 +22,6 @@
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(default)
-
 extern "C" {
 
 void
@@ -55,6 +53,4 @@ __cxa_uncaught_exceptions() throw() { return 0; }
 
 }  // extern "C"
 
-#pragma GCC visibility pop
-
 }  // abi

libcxxabi/src/cxa_thread_atexit.cpp

@@ -20,7 +20,7 @@ namespace __cxxabiv1 {
 #ifndef HAVE___CXA_THREAD_ATEXIT_IMPL
   // A weak symbol is used to detect this function's presence in the C library
   // at runtime, even if libc++ is built against an older libc
-  __attribute__((__weak__))
+  _LIBCXXABI_WEAK
 #endif
   int __cxa_thread_atexit_impl(Dtor, void*, void*);
 

libcxxabi/src/cxa_unexpected.cpp

@@ -14,14 +14,10 @@
 namespace __cxxabiv1
 {
 
-#pragma GCC visibility push(default)
-
 extern "C"
 {
 
 }
 
-#pragma GCC visibility pop
-
 }  // namespace __cxxabiv1
 

libcxxabi/src/fallback_malloc.cpp

@@ -194,8 +194,6 @@ size_t print_free_list () {
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(hidden)
-
 void * __malloc_with_fallback(size_t size) {
     void *ptr = std::malloc(size);
     if (NULL == ptr) // if malloc fails, fall back to emergency stash
@@ -221,6 +219,4 @@ void __free_with_fallback(void *ptr) {
         std::free(ptr);
 }
 
-#pragma GCC visibility pop
-
 } // namespace __cxxabiv1

libcxxabi/src/fallback_malloc.h

@@ -10,21 +10,18 @@
 #ifndef _FALLBACK_MALLOC_H
 #define _FALLBACK_MALLOC_H
 
+#include "__cxxabi_config.h"
 #include <cstddef> // for size_t
 
 namespace __cxxabiv1 {
 
-#pragma GCC visibility push(hidden)
-
 // Allocate some memory from _somewhere_
-void * __malloc_with_fallback(size_t size);
+_LIBCXXABI_HIDDEN void * __malloc_with_fallback(size_t size);
 
 // Allocate and zero-initialize memory from _somewhere_
-void * __calloc_with_fallback(size_t count, size_t size);
+_LIBCXXABI_HIDDEN void * __calloc_with_fallback(size_t count, size_t size);
 
-void __free_with_fallback(void *ptr);
-
-#pragma GCC visibility pop
+_LIBCXXABI_HIDDEN void __free_with_fallback(void *ptr);
 
 } // namespace __cxxabiv1
 

libcxxabi/src/private_typeinfo.cpp

@@ -55,12 +55,7 @@
 #include <string.h>
 #endif
 
-namespace __cxxabiv1
-{
-
-#pragma GCC visibility push(hidden)
-
-inline
+static inline
 bool
 is_equal(const std::type_info* x, const std::type_info* y, bool use_strcmp)
 {
@@ -73,6 +68,8 @@ is_equal(const std::type_info* x, const std::type_info* y, bool use_strcmp)
 #endif
 }
 
+namespace __cxxabiv1
+{
 
 // __shim_type_info
 
@@ -538,9 +535,6 @@ bool __pointer_to_member_type_info::can_catch_nested(
 #pragma clang diagnostic pop
 #endif
 
-#pragma GCC visibility pop
-#pragma GCC visibility push(default)
-
 #ifdef __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wmissing-field-initializers"
@@ -715,9 +709,6 @@ __dynamic_cast(const void *static_ptr, const __class_type_info *static_type,
 #pragma clang diagnostic pop
 #endif
 
-#pragma GCC visibility pop
-#pragma GCC visibility push(hidden)
-
 // Call this function when you hit a static_type which is a base (above) a dst_type.
 // Let caller know you hit a static_type.  But only start recording details if
 // this is (static_ptr, static_type) -- the node we are casting from.
@@ -1300,6 +1291,4 @@ __base_class_type_info::search_below_dst(__dynamic_cast_info* info,
                                   use_strcmp);
 }
 
-#pragma GCC visibility pop
-
 }  // __cxxabiv1

libcxxabi/src/private_typeinfo.h

@@ -16,7 +16,6 @@
 #include <cstddef>
 
 namespace __cxxabiv1 {
-#pragma GCC visibility push(hidden)
 
 class _LIBCXXABI_TYPE_VIS __shim_type_info : public std::type_info {
 public:
@@ -67,7 +66,7 @@ enum
 
 class _LIBCXXABI_TYPE_VIS __class_type_info;
 
-struct __dynamic_cast_info
+struct _LIBCXXABI_HIDDEN __dynamic_cast_info
 {
 // const data supplied to the search:
 
@@ -153,7 +152,7 @@ public:
   has_unambiguous_public_base(__dynamic_cast_info *, void *, int) const;
 };
 
-struct __base_class_type_info
+struct _LIBCXXABI_HIDDEN __base_class_type_info
 {
 public:
     const __class_type_info* __base_type;
@@ -248,8 +247,6 @@ public:
   _LIBCXXABI_HIDDEN bool can_catch_nested(const __shim_type_info *) const;
 };
 
-#pragma GCC visibility pop
-
 }  // __cxxabiv1
 
 #endif  // __PRIVATE_TYPEINFO_H_

libcxxabi/src/stdlib_exception.cpp

@@ -9,8 +9,6 @@
 
 #include <exception>
 
-#pragma GCC visibility push(default)
-
 namespace std
 {
 
@@ -37,5 +35,3 @@ const char* bad_exception::what() const _NOEXCEPT
 }
 
 }  // std
-
-#pragma GCC visibility pop