[libcxx-commits] [libcxx] [libcxx] Support ABI symbol sizes on macOS (PR #75623)

[Will Hawkins via libcxx-commits]

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@@ -195,6 +195,26 @@ split_list(LIBCXX_LINK_FLAGS)
 
 # Build the shared library.
 if (LIBCXX_ENABLE_SHARED)
+
+  if (APPLE)
+    # If we are on an Apple platform, let's ask the linker to generate a map
+    # that we can use to determine the size of the abi symbols (see generate-cxx-abilist target).
+    if (CMAKE_CXX_COMPILER_TARGET)
+      set(triple "${CMAKE_CXX_COMPILER_TARGET}")
+    else()
+      set(triple "${LLVM_DEFAULT_TARGET_TRIPLE}")
+    endif()
+    cxx_abi_identifier(abi_identifier
+      "${triple}"
+      "${LIBCXX_CXX_ABI}"
+      "${LIBCXX_ABI_VERSION}"
+      "${LIBCXX_ABI_UNSTABLE}"
+      "${LIBCXX_ENABLE_EXCEPTIONS}"
+      "${LIBCXX_ENABLE_NEW_DELETE_DEFINITIONS}"
+    )
+    add_link_flags("-Wl,-map,${CMAKE_CURRENT_BINARY_DIR}/../lib/abi/linker.map")
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hawkinsw wrote:

Great. Will do! 

https://github.com/llvm/llvm-project/pull/75623