libclang.so: Make SONAME independent from LLVM version

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D105527

clang/test/CMakeLists.txt

@@ -37,6 +37,7 @@ configure_lit_site_cfg(
   "CLANG_BINARY_DIR"
   "CLANG_SOURCE_DIR"
   "CLANG_TOOLS_DIR"
+  "CMAKE_LIBRARY_OUTPUT_DIRECTORY"
   )
 
 configure_lit_site_cfg(

clang/test/LibClang/lit.local.cfg

@@ -0,0 +1,2 @@
+config.substitutions.append(('%libclang', os.path.join(config.clang_lib_dir, 'libclang.so')))
+config.pipefail = False

clang/test/LibClang/symbols.test

@@ -0,0 +1,6 @@
+# Check that there are no unversioned clang symbols in libclang.so
+RUN: llvm-nm -Dj --defined-only %libclang | grep -v -e '@@LLVM_[0-9]\+$' | not grep '^clang'
+
+# Check that here are no local clang_ symbols (ignoring symbols with .cold or
+# .localalias suffxies.)
+RUN: llvm-nm %libclang | not grep '[a-z] clang_[^.]\+$'

clang/test/lit.site.cfg.py.in

@@ -14,6 +14,7 @@ config.clang_lit_site_cfg = __file__
 config.clang_obj_root = path(r"@CLANG_BINARY_DIR@")
 config.clang_src_dir = path(r"@CLANG_SOURCE_DIR@")
 config.clang_tools_dir = path(r"@CLANG_TOOLS_DIR@")
+config.clang_lib_dir = path(r"@CMAKE_LIBRARY_OUTPUT_DIRECTORY@")
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@TARGET_TRIPLE@"
 config.host_cc = "@CMAKE_C_COMPILER@"

clang/tools/libclang/CMakeLists.txt

@@ -65,6 +65,7 @@ option(LIBCLANG_BUILD_STATIC
   "Build libclang as a static library (in addition to a shared one)" OFF)
 
 set(LLVM_EXPORTED_SYMBOL_FILE ${CMAKE_CURRENT_SOURCE_DIR}/libclang.exports)
+set(LIBCLANG_VERSION_SCRIPT_FILE ${CMAKE_CURRENT_SOURCE_DIR}/libclang.map)
 
 if(MSVC)
   # Avoid LNK4197 by not specifying libclang.exports here.
@@ -73,6 +74,20 @@ if(MSVC)
   set(LLVM_EXPORTED_SYMBOL_FILE)
 endif()
 
+if (UNIX AND NOT APPLE)
+  set(LLVM_EXPORTED_SYMBOL_FILE)
+  set(USE_VERSION_SCRIPT TRUE)
+endif()
+
+if (LLVM_EXPORTED_SYMBOL_FILE)
+  add_custom_command(OUTPUT ${LLVM_EXPORTED_SYMBOL_FILE}
+                     COMMAND "${Python3_EXECUTABLE}"
+                       ARGS ${CMAKE_CURRENT_SOURCE_DIR}/linker-script-to-export-list.py
+                            ${LIBCLANG_VERSION_SCRIPT_FILE}
+                            ${LLVM_EXPORTED_SYMBOL_FILE}
+                     DEPENDS ${LIBCLANG_VERSION_SCRIPT_FILE})
+endif()
+
 if(LLVM_ENABLE_PIC OR (WIN32 AND NOT LIBCLANG_BUILD_STATIC))
   set(ENABLE_SHARED SHARED)
 endif()
@@ -145,6 +160,19 @@ if(ENABLE_SHARED)
         )
     endif()
   endif()
+  if (USE_VERSION_SCRIPT)
+    target_link_options(libclang PRIVATE "-Wl,--version-script,${CMAKE_CURRENT_SOURCE_DIR}/libclang.map")
+    # Ensure that libclang.so gets rebuilt when the linker script changes.
+    set_property(SOURCE ARCMigrate.cpp APPEND PROPERTY
+                 OBJECT_DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/libclang.map)
+
+    # The SOVERSION should be updated only if a change is made to the libclang
+    # ABI, and when it is updated, it should be updated to the current
+    # LLVM_VERSION_MAJOR.
+    set_target_properties(libclang PROPERTIES
+                          VERSION ${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}${LLVM_VERSION_SUFFIX}
+                          SOVERSION 13)
+  endif()
 endif()
 
 if(INTERNAL_INSTALL_PREFIX)