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| author | Jakub Zakrzewski <slither.jz@gmail.com> | 2016-09-04 12:37:46 +0200 |
|---|---|---|
| committer | Jakub Zakrzewski <slither.jz@gmail.com> | 2016-09-10 00:35:38 +0200 |
| commit | 6140dfcf3e7845f11dee755de6865379aa96dab7 (patch) | |
| tree | b04e4001ee22651132fda45756d04105362514d1 /CMake | |
| parent | 83ef21e5e9946de2805ae10cc5e6ef9431b22702 (diff) | |
CMake: Try to (un-)hide private library symbols
Detect support for compiler symbol visibility flags and apply those
according to CURL_HIDDEN_SYMBOLS option.
It should work true to the autotools build except it tries to unhide
symbols on Windows when requested and prints warning if it fails.
Ref: https://github.com/curl/curl/issues/981#issuecomment-242665951
Reported-by: Daniel Stenberg
Diffstat (limited to 'CMake')
| -rw-r--r-- | CMake/CurlSymbolHiding.cmake | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/CMake/CurlSymbolHiding.cmake b/CMake/CurlSymbolHiding.cmake new file mode 100644 index 000000000..9f7d29633 --- /dev/null +++ b/CMake/CurlSymbolHiding.cmake @@ -0,0 +1,61 @@ +include(CheckCSourceCompiles) + +option(CURL_HIDDEN_SYMBOLS "Set to ON to hide libcurl internal symbols (=hide all symbols that aren't officially external)." ON) +mark_as_advanced(CURL_HIDDEN_SYMBOLS) + +if(CURL_HIDDEN_SYMBOLS) + set(SUPPORTS_SYMBOL_HIDING FALSE) + + if(CMAKE_C_COMPILER_ID MATCHES "Clang") + set(SUPPORTS_SYMBOL_HIDING TRUE) + set(_SYMBOL_EXTERN "__attribute__ ((__visibility__ (\"default\")))") + set(_CFLAG_SYMBOLS_HIDE "-fvisibility=hidden") + elseif(CMAKE_COMPILER_IS_GNUCC) + if(NOT CMAKE_VERSION VERSION_LESS 2.8.10) + set(GCC_VERSION ${CMAKE_C_COMPILER_VERSION}) + else() + execute_process(COMMAND ${CMAKE_C_COMPILER} -dumpversion + OUTPUT_VARIABLE GCC_VERSION) + endif() + if(NOT GCC_VERSION VERSION_LESS 3.4) + # note: this is considered buggy prior to 4.0 but the autotools don't care, so let's ignore that fact + set(SUPPORTS_SYMBOL_HIDING TRUE) + set(_SYMBOL_EXTERN "__attribute__ ((__visibility__ (\"default\")))") + set(_CFLAG_SYMBOLS_HIDE "-fvisibility=hidden") + endif() + elseif(CMAKE_C_COMPILER_ID MATCHES "SunPro" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 8.0) + set(SUPPORTS_SYMBOL_HIDING TRUE) + set(_SYMBOL_EXTERN "__global") + set(_CFLAG_SYMBOLS_HIDE "-xldscope=hidden") + elseif(CMAKE_C_COMPILER_ID MATCHES "Intel" AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS 9.0) + # note: this should probably just check for version 9.1.045 but I'm not 100% sure + # so let's to it the same way autotools do. + set(SUPPORTS_SYMBOL_HIDING TRUE) + set(_SYMBOL_EXTERN "__attribute__ ((__visibility__ (\"default\")))") + set(_CFLAG_SYMBOLS_HIDE "-fvisibility=hidden") + check_c_source_compiles("#include <stdio.h> + int main (void) { printf(\"icc fvisibility bug test\"); return 0; }" _no_bug) + if(NOT _no_bug) + set(SUPPORTS_SYMBOL_HIDING FALSE) + set(_SYMBOL_EXTERN "") + set(_CFLAG_SYMBOLS_HIDE "") + endif() + elseif(MSVC) + set(SUPPORTS_SYMBOL_HIDING TRUE) + endif() + + set(HIDES_CURL_PRIVATE_SYMBOLS ${SUPPORTS_SYMBOL_HIDING}) +elseif(MSVC) + if(NOT CMAKE_VERSION VERSION_LESS 3.7) + set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS TRUE) #present since 3.4.3 but broken + set(HIDES_CURL_PRIVATE_SYMBOLS FALSE) + else() + message(WARNING "Hiding private symbols regardless CURL_HIDDEN_SYMBOLS being disabled.") + set(HIDES_CURL_PRIVATE_SYMBOLS TRUE) + endif() +elseif() + set(HIDES_CURL_PRIVATE_SYMBOLS FALSE) +endif() + +set(CURL_CFLAG_SYMBOLS_HIDE ${_CFLAG_SYMBOLS_HIDE}) +set(CURL_EXTERN_SYMBOL ${_SYMBOL_EXTERN}) |