[libc++] Simplify how we re-export symbols from libc++abi

[ldionne]

Summary

Instead of managing two copies of the symbol lists, reuse the same list
in libc++abi and libc++.

[ldionne]

Builds passed at https://buildkite.com/llvm-project/libcxx-ci/builds/24

[JDevlieghere]

Hey Louis, this seems to break on the LLDB bots. Can you please take a look if you haven't done so already?

ld: requested re-export symbol operator new(unsigned long) is not from a dylib, but from projects/libcxx/src/CMakeFiles/cxx_shared.dir/new.cpp.o
 file 'projects/libcxx/src/CMakeFiles/cxx_shared.dir/new.cpp.o' for architecture x86_64

http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/24039/console

[ldionne]

In D88623#2306433, @JDevlieghere wrote:

Hey Louis, this seems to break on the LLDB bots. Can you please take a look if you haven't done so already?

ld: requested re-export symbol operator new(unsigned long) is not from a dylib, but from projects/libcxx/src/CMakeFiles/cxx_shared.dir/new.cpp.o
 file 'projects/libcxx/src/CMakeFiles/cxx_shared.dir/new.cpp.o' for architecture x86_64

http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/24039/console

I'm working on a fix right now, I should commit it momentarily.

[ldionne]

In D88623#2306581, @ldionne wrote:

In D88623#2306433, @JDevlieghere wrote:

Hey Louis, this seems to break on the LLDB bots. Can you please take a look if you haven't done so already?

ld: requested re-export symbol operator new(unsigned long) is not from a dylib, but from projects/libcxx/src/CMakeFiles/cxx_shared.dir/new.cpp.o
 file 'projects/libcxx/src/CMakeFiles/cxx_shared.dir/new.cpp.o' for architecture x86_64

http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/24039/console

I'm working on a fix right now, I should commit it momentarily.

8654a0f8bbf3e28eb210c75c8c70c739de637226

[JDevlieghere]

Thanks!

libcxx/lib/abi/CHANGELOG.TXT

 ABI Changelog
 ==============
 This changelog contains information about ABI changes in libc++. Specifically
 the addition and deletion of symbols from the libc++ dylib.
 
 Each entry should start with the revision number followed by a description of
 the change. The entry should contain a summary of the ABI changes made,
 including what symbols were added, removed, or changed.
 
 To generate a summary use "sym_diff.py" diffing against the appropriate ABI list.
 Afterwards the ABI list should be updated to include the new changes.
 
 New entries should be added directly below the "Version" header.
 
 ------------
+Version 12.0
+------------
+
+* XXXXXXX - [libc++] Simplify how we re-export symbols from libc++abi
+
+  We re-export some symbols that were exported from libc++abi but not from
+  libc++. Exporting new symbols is not an ABI break.
+
+  x86_64-apple-apple-darwin
+  -------------------------
+  Symbol added: ___cxa_allocate_dependent_exception
+  Symbol added: ___cxa_free_dependent_exception
+
+------------
 Version 10.0
 ------------
 
 * 54fa9ecd3088 - [libc++] Implementation of C++20's P1135R6 for libcxx
 
   libc++ now implements P1135R6 (The C++20 Synchronization Library), which
   adds a few symbols to the dylib. This is backwards-compatible since we're
   just adding new symbols.

libcxx/lib/abi/x86_64-apple-darwin.v1.abilist

 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__123__cxx_atomic_notify_allEPVKv'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__123__cxx_atomic_notify_oneEPVKNS_17__cxx_atomic_implIxNS_22__cxx_atomic_base_implIxEEEE'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__123__cxx_atomic_notify_oneEPVKv'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__123__libcpp_atomic_monitorEPVKNS_17__cxx_atomic_implIxNS_22__cxx_atomic_base_implIxEEEE'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__123__libcpp_atomic_monitorEPVKv'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__131__arrive_barrier_algorithm_baseEPNS_24__barrier_algorithm_baseEh'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__132__destroy_barrier_algorithm_baseEPNS_24__barrier_algorithm_baseE'}
 {'type': 'FUNC', 'is_defined': True, 'name': '__ZNSt3__134__construct_barrier_algorithm_baseERl'}
+{'type': 'U', 'is_defined': False, 'name': '___cxa_allocate_dependent_exception'}
+{'type': 'U', 'is_defined': False, 'name': '___cxa_free_dependent_exception'}
+{'type': 'I', 'is_defined': True, 'name': '___cxa_allocate_dependent_exception'}
+{'type': 'I', 'is_defined': True, 'name': '___cxa_free_dependent_exception'}

libcxx/lib/libc++abi-exceptions.exp

-___cxa_allocate_exception
-___cxa_begin_catch
-___cxa_call_unexpected
-___cxa_current_exception_type
-___cxa_end_catch
-___cxa_free_exception
-___cxa_get_exception_ptr
-___cxa_rethrow
-___cxa_throw
-___gxx_personality_v0

libcxx/lib/libc++abi-exceptions.sjlj.exp

-___cxa_allocate_exception
-___cxa_begin_catch
-___cxa_call_unexpected
-___cxa_current_exception_type
-___cxa_end_catch
-___cxa_free_exception
-___cxa_get_exception_ptr
-___cxa_rethrow
-___cxa_throw
-___gxx_personality_sj0

libcxx/lib/libc++abi-new-delete.exp

-__ZdaPv
-__ZdaPvRKSt9nothrow_t
-__ZdaPvSt11align_val_t
-__ZdaPvSt11align_val_tRKSt9nothrow_t
-__ZdaPvm
-__ZdaPvmSt11align_val_t
-__ZdlPv
-__ZdlPvRKSt9nothrow_t
-__ZdlPvSt11align_val_t
-__ZdlPvSt11align_val_tRKSt9nothrow_t
-__ZdlPvm
-__ZdlPvmSt11align_val_t
-__Znam
-__ZnamRKSt9nothrow_t
-__ZnamSt11align_val_t
-__ZnamSt11align_val_tRKSt9nothrow_t
-__Znwm
-__ZnwmRKSt9nothrow_t
-__ZnwmSt11align_val_t
-__ZnwmSt11align_val_tRKSt9nothrow_t

libcxx/src/CMakeLists.txt

if (LIBCXX_ENABLE_SHARED)
   endif()
 
   if (LIBCXX_OSX_REEXPORT_LIBCXXABI_SYMBOLS)
     target_link_libraries(cxx_shared PRIVATE
       "-Wl,-unexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/libc++unexp.exp"
       "-Wl,-reexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/libc++abi.v${LIBCXX_LIBCPPABI_VERSION}.exp"
       "-Wl,-force_symbols_not_weak_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/notweak.exp"
       "-Wl,-force_symbols_weak_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/weak.exp")
-
-    if (LIBCXX_ENABLE_EXCEPTIONS)
-      if ("${CMAKE_OSX_ARCHITECTURES}" MATCHES "^(armv6|armv7|armv7s)$")
-        target_link_libraries(cxx_shared PRIVATE "-Wl,-reexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/libc++abi-exceptions.sjlj.exp")
-      else()
-        target_link_libraries(cxx_shared PRIVATE "-Wl,-reexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/libc++abi-exceptions.exp")
-      endif()
-    endif()
-
-    if (NOT LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS)
-      target_link_libraries(cxx_shared PRIVATE "-Wl,-reexported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/libc++abi-new-delete.exp")
-    endif()
   endif()
 
   # Generate a linker script in place of a libc++.so symlink.
   if (LIBCXX_ENABLE_ABI_LINKER_SCRIPT)
       include(DefineLinkerScript)
       define_linker_script(cxx_shared)
   endif()
 

libcxxabi/src/CMakeLists.txt

if (LIBCXXABI_ENABLE_SHARED)
 
   list(APPEND LIBCXXABI_BUILD_TARGETS "cxxabi_shared")
   if (LIBCXXABI_INSTALL_SHARED_LIBRARY)
     list(APPEND LIBCXXABI_INSTALL_TARGETS "cxxabi_shared")
   endif()
 
   # -exported_symbols_list is only available on Apple platforms
   if (APPLE)
-    target_link_libraries(cxxabi_shared PRIVATE "-Wl,-exported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/itanium-base.exp")
+    function(export_symbols file)
+      target_link_libraries(cxxabi_shared PRIVATE "-Wl,-exported_symbols_list,${file}")
+    endfunction()
+    function(reexport_symbols file)
+      export_symbols("${file}")
+      target_link_libraries(cxxabi_shared INTERFACE "-Wl,-reexported_symbols_list,${file}")
+    endfunction()
+
+    export_symbols("${CMAKE_CURRENT_SOURCE_DIR}/../lib/itanium-base.exp")
 
     if (LIBCXXABI_ENABLE_NEW_DELETE_DEFINITIONS)
-      target_link_libraries(cxxabi_shared PRIVATE "-Wl,-exported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/new-delete.exp")
+      reexport_symbols("${CMAKE_CURRENT_SOURCE_DIR}/../lib/new-delete.exp")
     endif()
 
     if (LIBCXXABI_ENABLE_EXCEPTIONS)
-      target_link_libraries(cxxabi_shared PRIVATE "-Wl,-exported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/exceptions.exp")
+      reexport_symbols("${CMAKE_CURRENT_SOURCE_DIR}/../lib/exceptions.exp")
 
       if ("${CMAKE_OSX_ARCHITECTURES}" MATCHES "^(armv6|armv7|armv7s)$")
-        target_link_libraries(cxxabi_shared PRIVATE "-Wl,-exported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/personality-sjlj.exp")
+        reexport_symbols("${CMAKE_CURRENT_SOURCE_DIR}/../lib/personality-sjlj.exp")
       else()
-        target_link_libraries(cxxabi_shared PRIVATE "-Wl,-exported_symbols_list,${CMAKE_CURRENT_SOURCE_DIR}/../lib/personality-v0.exp")
+        reexport_symbols("${CMAKE_CURRENT_SOURCE_DIR}/../lib/personality-v0.exp")
       endif()
     endif()
   endif()
 endif()
 
 # Build the static library.
 if (LIBCXXABI_ENABLE_STATIC)
   add_library(cxxabi_static STATIC ${LIBCXXABI_SOURCES} ${LIBCXXABI_HEADERS})