curl/CMake/CurlSymbolHiding.cmake
Viktor Szakats a8ebde99f7
cmake: lib CURL_STATICLIB fixes (Windows)
- always define `CURL_STATICLIB` when building libcurl for Windows.

  This disables `__declspec(dllexport)` for exported libcurl symbols.
  In normal mode (hide symbols) these exported symbols are specified
  via `libcurl.def`. When not hiding symbols, all symbols are exported
  by default.

  Regression from 1199308dbc

  Fixes #11844

- fix to omit `libcurl.def` when not hiding private symbols.

  Regression from 2ebc74c36a

- fix `ENABLED_DEBUG=ON` + shared curl tool Windows builds by also
  omitting `libcurl.def` in this case, and exporting all symbols
  instead. This ensures that a shared curl tool can access all debug
  functions which are not normally exported from libcurl DLL.

- delete `INTERFACE_COMPILE_DEFINITIONS "CURL_STATICLIB"` for "objects"
  target.

  Follow-up to 2ebc74c36a

- delete duplicate `BUILDING_LIBCURL` definitions.

- fix `HIDES_CURL_PRIVATE_SYMBOLS` to not overwrite earlier build settings.

  Follow-up to 1199308dbc

Closes #11914
2023-09-25 22:05:29 +00:00

85 lines
3.5 KiB
CMake

#***************************************************************************
# _ _ ____ _
# Project ___| | | | _ \| |
# / __| | | | |_) | |
# | (__| |_| | _ <| |___
# \___|\___/|_| \_\_____|
#
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at https://curl.se/docs/copyright.html.
#
# You may opt to use, copy, modify, merge, publish, distribute and/or sell
# copies of the Software, and permit persons to whom the Software is
# furnished to do so, under the terms of the COPYING file.
#
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
# KIND, either express or implied.
#
# SPDX-License-Identifier: curl
#
###########################################################################
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(WIN32 AND ENABLE_CURLDEBUG)
# We need to export internal debug functions (e.g. curl_dbg_*), so disable
# symbol hiding for debug builds.
set(CURL_HIDDEN_SYMBOLS OFF)
endif()
if(CURL_HIDDEN_SYMBOLS)
set(SUPPORTS_SYMBOL_HIDING FALSE)
if(CMAKE_C_COMPILER_ID MATCHES "Clang" AND NOT MSVC)
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_C_COMPILER_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 do 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()
else()
set(HIDES_CURL_PRIVATE_SYMBOLS FALSE)
endif()
set(CURL_CFLAG_SYMBOLS_HIDE ${_CFLAG_SYMBOLS_HIDE})
set(CURL_EXTERN_SYMBOL ${_SYMBOL_EXTERN})