[WIP] Privatize NativeAOT libunwind symbols

src/coreclr/nativeaot/Runtime/CMakeLists.txt

@@ -179,8 +179,23 @@ else()
 
   include(${CLR_SRC_NATIVE_DIR}/external/llvm-libunwind.cmake)
 
-  list(APPEND FULL_RUNTIME_SOURCES ${LLVM_LIBUNWIND_SOURCES})
-  set(RUNTIME_SOURCES_ARCH_ASM ${LLVM_LIBUNWIND_ASM_SOURCES})
+  set(NATIVEAOT_LOCALIZE_LIBUNWIND_SYMBOLS OFF)
+  if(CLR_CMAKE_TARGET_UNIX AND NOT CLR_CMAKE_TARGET_APPLE AND NOT CLR_CMAKE_TARGET_ARCH_WASM)
+    set(NATIVEAOT_LOCALIZE_LIBUNWIND_SYMBOLS ON)
+  endif()
+
+  if(NATIVEAOT_LOCALIZE_LIBUNWIND_SYMBOLS)
+    set(NATIVEAOT_PRIVATE_LIBUNWIND_SOURCES
+      unix/UnwindHelpers.cpp
+      unix/UnixNativeCodeManager.cpp
+      ${LLVM_LIBUNWIND_SOURCES}
+      ${LLVM_LIBUNWIND_ASM_SOURCES})
+    list(REMOVE_ITEM FULL_RUNTIME_SOURCES unix/UnwindHelpers.cpp)
+    list(REMOVE_ITEM FULL_RUNTIME_SOURCES unix/UnixNativeCodeManager.cpp)
+  else()
+    list(APPEND FULL_RUNTIME_SOURCES ${LLVM_LIBUNWIND_SOURCES})
+    set(RUNTIME_SOURCES_ARCH_ASM ${LLVM_LIBUNWIND_ASM_SOURCES})
+  endif()
 
   set(ASM_SUFFIX S)
 endif()
@@ -316,6 +331,7 @@ convert_to_absolute_path(FULL_RUNTIME_SOURCES ${FULL_RUNTIME_SOURCES})
 convert_to_absolute_path(SERVER_GC_SOURCES ${SERVER_GC_SOURCES})
 convert_to_absolute_path(STANDALONEGC_DISABLED_SOURCES ${STANDALONEGC_DISABLED_SOURCES})
 convert_to_absolute_path(STANDALONEGC_ENABLED_SOURCES ${STANDALONEGC_ENABLED_SOURCES})
+convert_to_absolute_path(NATIVEAOT_PRIVATE_LIBUNWIND_SOURCES ${NATIVEAOT_PRIVATE_LIBUNWIND_SOURCES})
 convert_to_absolute_path(RUNTIME_SOURCES_ARCH_ASM ${RUNTIME_SOURCES_ARCH_ASM})
 convert_to_absolute_path(VXSORT_SOURCES ${VXSORT_SOURCES})
 convert_to_absolute_path(DUMMY_VXSORT_SOURCES ${DUMMY_VXSORT_SOURCES})

src/coreclr/nativeaot/Runtime/Full/CMakeLists.txt

@@ -22,11 +22,45 @@ if (CLR_CMAKE_TARGET_WIN32)
   endif()
 endif (CLR_CMAKE_TARGET_WIN32)
 
-add_library(Runtime.WorkstationGC STATIC ${COMMON_RUNTIME_SOURCES} ${FULL_RUNTIME_SOURCES} ${RUNTIME_ARCH_ASM_OBJECTS})
+if(NATIVEAOT_PRIVATE_LIBUNWIND_SOURCES)
+  add_library(Runtime.PrivateLibunwind OBJECT ${NATIVEAOT_PRIVATE_LIBUNWIND_SOURCES})
+
+  set(NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT "${CMAKE_CURRENT_BINARY_DIR}/Runtime.PrivateLibunwind.o")
+  set(NATIVEAOT_PRIVATE_LIBUNWIND_SYMBOLS "${CMAKE_CURRENT_BINARY_DIR}/Runtime.PrivateLibunwind.localize")
+  set(NATIVEAOT_PRIVATE_LIBUNWIND_LINKER "${CMAKE_LINKER}")
+  if(NATIVEAOT_PRIVATE_LIBUNWIND_LINKER MATCHES "llvm-link(\\.exe)?$")
+    get_filename_component(NATIVEAOT_PRIVATE_LIBUNWIND_TOOL_DIR "${CMAKE_NM}" DIRECTORY)
+    set(NATIVEAOT_PRIVATE_LIBUNWIND_LINKER "${NATIVEAOT_PRIVATE_LIBUNWIND_TOOL_DIR}/ld.lld")
+  endif()
+
+  add_custom_command(
+    OUTPUT "${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT}"
+    COMMAND "${CMAKE_COMMAND}" -E rm -f "${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT}"
+    COMMAND "${CMAKE_COMMAND}"
+            "-DNM_TOOL=${CMAKE_NM}"
+            "-DOUTPUT_FILE=${NATIVEAOT_PRIVATE_LIBUNWIND_SYMBOLS}"
+            "-DOBJECT_FILES=$<JOIN:$<TARGET_OBJECTS:Runtime.PrivateLibunwind>,|>"
+            -P "${CMAKE_CURRENT_LIST_DIR}/GeneratePrivateLibunwindSymbols.cmake"
+    COMMAND "${NATIVEAOT_PRIVATE_LIBUNWIND_LINKER}" -r $<TARGET_OBJECTS:Runtime.PrivateLibunwind> -o "${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT}"
+    COMMAND "${CMAKE_OBJCOPY}"
+            "--localize-symbols=${NATIVEAOT_PRIVATE_LIBUNWIND_SYMBOLS}"
+            "${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT}"
+    DEPENDS Runtime.PrivateLibunwind $<TARGET_OBJECTS:Runtime.PrivateLibunwind>
+    BYPRODUCTS "${NATIVEAOT_PRIVATE_LIBUNWIND_SYMBOLS}"
+    COMMENT "Privatizing NativeAOT libunwind symbols"
+    COMMAND_EXPAND_LISTS
+    VERBATIM
+  )
+  set_source_files_properties("${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT}" PROPERTIES
+    EXTERNAL_OBJECT TRUE
+    GENERATED TRUE)
+endif()
+
+add_library(Runtime.WorkstationGC STATIC ${COMMON_RUNTIME_SOURCES} ${FULL_RUNTIME_SOURCES} ${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT} ${RUNTIME_ARCH_ASM_OBJECTS})
 add_dependencies(Runtime.WorkstationGC aot_eventing_headers)
 target_link_libraries(Runtime.WorkstationGC PRIVATE aotminipal nativeaot_cdac_contract_descriptor nativeaot_gc_wks_descriptor)
 
-add_library(Runtime.ServerGC STATIC ${COMMON_RUNTIME_SOURCES} ${FULL_RUNTIME_SOURCES} ${SERVER_GC_SOURCES} ${RUNTIME_ARCH_ASM_OBJECTS})
+add_library(Runtime.ServerGC STATIC ${COMMON_RUNTIME_SOURCES} ${FULL_RUNTIME_SOURCES} ${NATIVEAOT_PRIVATE_LIBUNWIND_OBJECT} ${SERVER_GC_SOURCES} ${RUNTIME_ARCH_ASM_OBJECTS})
 add_dependencies(Runtime.ServerGC aot_eventing_headers)
 target_link_libraries(Runtime.ServerGC PRIVATE aotminipal nativeaot_cdac_contract_descriptor nativeaot_gc_wks_descriptor nativeaot_gc_svr_descriptor)
 

src/coreclr/nativeaot/Runtime/Full/GeneratePrivateLibunwindSymbols.cmake

@@ -0,0 +1,64 @@
+if(NOT DEFINED NM_TOOL)
+  message(FATAL_ERROR "NM_TOOL is required")
+endif()
+
+if(NOT DEFINED OUTPUT_FILE)
+  message(FATAL_ERROR "OUTPUT_FILE is required")
+endif()
+
+if(NOT DEFINED OBJECT_FILES)
+  message(FATAL_ERROR "OBJECT_FILES is required")
+endif()
+
+string(REPLACE "|" ";" OBJECT_FILE_LIST "${OBJECT_FILES}")
+set(SYMBOLS)
+
+foreach(OBJECT_FILE IN LISTS OBJECT_FILE_LIST)
+  if(OBJECT_FILE MATCHES "UnixNativeCodeManager\\.cpp\\.o$")
+    continue()
+  endif()
+
+  execute_process(
+    COMMAND "${NM_TOOL}" -g --defined-only "${OBJECT_FILE}"
+    RESULT_VARIABLE NM_RESULT
+    OUTPUT_VARIABLE NM_OUTPUT
+    ERROR_VARIABLE NM_ERROR)
+
+  if(NOT NM_RESULT EQUAL 0)
+    message(FATAL_ERROR "Failed to list symbols from ${OBJECT_FILE}: ${NM_ERROR}")
+  endif()
+
+  string(REPLACE "\n" ";" NM_LINES "${NM_OUTPUT}")
+  foreach(NM_LINE IN LISTS NM_LINES)
+    string(STRIP "${NM_LINE}" NM_LINE)
+    if(NM_LINE STREQUAL "")
+      continue()
+    endif()
+
+    string(REGEX REPLACE "[ \t]+" ";" NM_FIELDS "${NM_LINE}")
+    list(LENGTH NM_FIELDS NM_FIELD_COUNT)
+    if(NM_FIELD_COUNT LESS 3)
+      continue()
+    endif()
+
+    list(GET NM_FIELDS 2 SYMBOL_NAME)
+
+    # UnwindHelpers.cpp is linked into the private libunwind object because it
+    # instantiates libunwind templates and references libunwind assembly
+    # helpers. Its public runtime entrypoints must remain externally visible to
+    # UnixNativeCodeManager.cpp.
+    if(SYMBOL_NAME MATCHES "^_ZN13UnwindHelpers")
+      continue()
+    endif()
+
+    list(APPEND SYMBOLS "${SYMBOL_NAME}")
+  endforeach()
+endforeach()
+
+list(REMOVE_DUPLICATES SYMBOLS)
+list(SORT SYMBOLS)
+
+file(WRITE "${OUTPUT_FILE}" "")
+foreach(SYMBOL IN LISTS SYMBOLS)
+  file(APPEND "${OUTPUT_FILE}" "${SYMBOL}\n")
+endforeach()