kicad-developers team mailing list archive

[Simon Richter <Simon.Richter@xxxxxxxxxx>]

Hi,

this is an improved version of the earlier patch, using the visibility
handling in CMake 3.3, and falling back to changing the global CXXFLAGS on
previous versions.

As CMake 3.3 attempts to be compatible with earlier versions, the new
behaviour needs to be explicitly enabled until 3.3 becomes the minimum
supported version, so this is done, and a warning added to remind whoever
bumps the minimum requirement to remove the compatibility code as well.

   Simon

---
 CMakeLists.txt                          | 32 ++++++++++++++++++++++++--------
 CMakeModules/PerformFeatureChecks.cmake |  2 --
 2 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6e44994..ea2fcee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -87,6 +87,30 @@ option( BUILD_GITHUB_PLUGIN "Build the GITHUB_PLUGIN for pcbnew." ON )
 set( KICAD_REPO_NAME "product" CACHE STRING "Name of the tree from which this build came." )
 
 
+# Global setting: exports are explicit
+set( CMAKE_CXX_VISIBILITY_PRESET "hidden" )
+set( CMAKE_VISIBILITY_INLINES_HIDDEN ON )
+
+
+# CMP0063: CMake < 3.3 does not handle hidden visibility for static libraries,
+# and 3.3 is backwards compatible when the minimum version is smaller than 3.3.
+if( POLICY CMP0063 )
+    cmake_policy( GET CMP0063 VISIBILITY_POLICY )
+    if( VISIBILITY_POLICY STREQUAL NEW )
+        message( WARNING "Compatibility code for CMake < 3.3 can be removed, search for CMP0063" )
+    else()
+        cmake_policy( GET CMP0063 NEW )
+    endif()
+else()
+    if( CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY AND NOT APPLE )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY}hidden" )
+    endif()
+    if( CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN AND NOT APPLE )
+        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN}" )
+    endif()
+endif()
+
+
 # All CMake downloads go here.  Suggested is up in the source tree, not in the build dir where they
 # would have to be downloaded over and over again.  The default is to choose a directory that is
 # hidden on linux (starts with a '.') because there is a way to exclude this directory when grepping
@@ -164,14 +188,6 @@ if( CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang" )
     set( CMAKE_C_FLAGS_RELEASE   "${CMAKE_C_FLAGS_RELEASE} -DNDEBUG" )
     set( CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DNDEBUG" )
 
-    if( GXX_HAS_VISIBILITY_FLAG AND NOT APPLE )
-        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden" )
-    endif()
-
-    if( GXX_HAS_VISIBILITY_INLINES_FLAG AND NOT APPLE )
-        set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility-inlines-hidden" )
-    endif()
-
     find_package( OpenMP QUIET )
 
     if( OPENMP_FOUND )
diff --git a/CMakeModules/PerformFeatureChecks.cmake b/CMakeModules/PerformFeatureChecks.cmake
index 0240046..531ab27 100644
--- a/CMakeModules/PerformFeatureChecks.cmake
+++ b/CMakeModules/PerformFeatureChecks.cmake
@@ -47,8 +47,6 @@ macro( perform_feature_checks )
     include( CheckCXXSourceCompiles )
     include( CheckCXXCompilerFlag )
 
-    check_cxx_compiler_flag( -fvisibility=hidden GXX_HAS_VISIBILITY_FLAG )
-    check_cxx_compiler_flag( -fvisibility-inlines-hidden GXX_HAS_VISIBILITY_INLINES_FLAG )
 
     check_include_file( "malloc.h" HAVE_MALLOC_H )