More cmake enhancements

CMakeLists.txt

@@ -47,22 +47,25 @@ option(XMLWRAPP_DOC "Build and install the documentation (requires Doxygen)" ${P
 option(XMLWRAPP_EXAMPLES "Build examples" ${PROJECT_IS_TOP_LEVEL})
 option(XMLWRAPP_TESTS "Build tests" ${PROJECT_IS_TOP_LEVEL})
 
-# This is always disabled but can be disabled by the super-project if it is
-# not needed before calling add_subdirectory().
+# This is always enabled but can be disabled by the super-project if it is not
+# needed before calling add_subdirectory().
 option(XMLWRAPP_WITH_LIBXSLT "Build libxsltwrapp library" ON)
 
+# These options are not set by default but can be used to customize the naming
+# of the produced libraries.
+set(XMLWRAPP_NAME_PREFIX "" CACHE STRING "Use the given prefix for the libraries")
+set(XMLWRAPP_NAME_SUFFIX "" CACHE STRING "Use the given suffix for the libraries")
+
 include(GNUInstallDirs)
 set(INSTALL_CMAKE_DIR ${CMAKE_INSTALL_LIBDIR}/cmake/xmlwrapp)
 
-set(CMAKE_CXX_COMPILER_VISIBILITY_PRESET hidden)
-
 find_package(PkgConfig)
 
-pkg_search_module(LIBXML2 REQUIRED libxml-2.0 >= 2.4.28)
+pkg_check_modules(LIBXML2 REQUIRED libxml-2.0>=2.4.28)
 
 if( XMLWRAPP_WITH_LIBXSLT )
-  pkg_search_module(LIBXSLT REQUIRED libxslt >= 1.1.6)
-  pkg_search_module(LIBEXSLT REQUIRED libexslt)
+  pkg_check_modules(LIBXSLT REQUIRED libxslt>=1.1.6)
+  pkg_check_modules(LIBEXSLT REQUIRED libexslt)
 endif( XMLWRAPP_WITH_LIBXSLT )
 
 
@@ -189,7 +192,14 @@ add_custom_target(distcheck
   VERBATIM
 )
 
-# Give build summary at the end.
+# Give build summary at the end but only if it's the first time we're running,
+# as indicated by XMLWRAPP_SUMMARY not being cached yet, or if it has changed.
+set(XMLWRAPP_SUMMARY_NOW
+  "${XMLWRAPP_VERSION}-${XMLWRAPP_LIB_TYPE}-${CMAKE_BUILD_TYPE}-${XMLWRAPP_WITH_LIBXSLT}-${XMLWRAPP_DOC}-${XMLWRAPP_EXAMPLES}-${XMLWRAPP_TESTS}"
+)
+if(NOT "${XMLWRAPP_SUMMARY_NOW}" STREQUAL "$CACHE{XMLWRAPP_SUMMARY}")
+set(XMLWRAPP_SUMMARY ${XMLWRAPP_SUMMARY_NOW} CACHE INTERNAL "xmlwrapp internal build summary")
+
 if (CMAKE_BUILD_TYPE)
   set(XMLWRAPP_CONFIG_DESCRIPTION " in ${CMAKE_BUILD_TYPE} configuration")
 endif()
@@ -198,3 +208,5 @@ message(STATUS "  Build xsltwrapp: ${XMLWRAPP_WITH_LIBXSLT}")
 message(STATUS "  Documentation:   ${XMLWRAPP_DOC}")
 message(STATUS "  Examples:        ${XMLWRAPP_EXAMPLES}")
 message(STATUS "  Tests:           ${XMLWRAPP_TESTS}")
+
+endif()

build/cmake/XmlwrappConfig.cmake.in

@@ -31,6 +31,15 @@ endif(XMLWRAPP_XSLT_FOUND)
 # Our library dependencies (contains definitions form IMPORTED targets)
 include("${CMAKE_CURRENT_LIST_DIR}/XmlwrappTargets.cmake")
 
+# Create alias targets if they don't exist yet (normally they should not, but
+# if find_package() is somehow used twice, this might happen).
+if(NOT TARGET xmlwrapp::xmlwrapp)
+  add_library(xmlwrapp::xmlwrapp ALIAS xmlwrapp)
+endif()
+if(XMLWRAPP_XSLT_FOUND AND NOT TARGET xmlwrapp::xsltwrapp)
+  add_library(xmlwrapp::xsltwrapp ALIAS xsltwrapp)
+endif()
+
 # These are imported targets created by XmlwrappTargets.cmake
 set(XMLWRAPP_XML_LIBRARIES xmlwrapp)
 if(XMLWRAPP_XSLT_FOUND)

examples/cmake/add_subdirectory/CMakeLists.txt

@@ -43,4 +43,4 @@ set(XMLWRAPP_WITH_LIBXSLT OFF)
 add_subdirectory(../../.. ${CMAKE_CURRENT_BINARY_DIR}/xmlwrapp)
 
 add_executable(example example.cpp)
-target_link_libraries(example PRIVATE xmlwrapp)
+target_link_libraries(example PRIVATE xmlwrapp::xmlwrapp)

examples/cmake/find_package/CMakeLists.txt

@@ -38,4 +38,4 @@ project(XmlwrappFindPackageExample
 find_package(Xmlwrapp 0.10 REQUIRED)
 
 add_executable(example example.cpp)
-target_link_libraries(example PRIVATE xmlwrapp)
+target_link_libraries(example PRIVATE xmlwrapp::xmlwrapp)

include/xmlwrapp/version.h

@@ -39,6 +39,8 @@
 #ifndef _xmlwrapp_version_h_
 #define _xmlwrapp_version_h_
 
+#include "xmlwrapp/export.h"
+
 /**
     Compile-time major version of the library.
 
@@ -118,7 +120,7 @@ namespace xml
 
     @since 0.10.0
  */
-int get_major_version();
+XMLWRAPP_API int get_major_version();
 
 /**
     Return minor runtime version of xmlwrapp library.
@@ -127,7 +129,7 @@ int get_major_version();
 
     @since 0.10.0
  */
-int get_minor_version();
+XMLWRAPP_API int get_minor_version();
 
 /**
     Return micro runtime version of xmlwrapp library.
@@ -136,7 +138,7 @@ int get_minor_version();
 
     @since 0.10.0
  */
-int get_micro_version();
+XMLWRAPP_API int get_micro_version();
 
 /**
     Return the full runtime version of xmlwrapp library.
@@ -147,7 +149,7 @@ int get_micro_version();
 
     @since 0.10.0
  */
-const char* get_version_string();
+XMLWRAPP_API const char* get_version_string();
 
 /**
     Check that the library version is at least the given one.
@@ -159,7 +161,7 @@ const char* get_version_string();
 
     @since 0.10.0
  */
-bool check_version(int major, int minor, int micro);
+XMLWRAPP_API bool check_version(int major, int minor, int micro);
 
 } // namespace xml
 

src/CMakeLists.txt

@@ -1,3 +1,44 @@
+# Configure shared library with the given name and (full) ELF version.
+#
+# Set properties for using hidden ELF visibility, defining proper DLL-related
+# symbols and use $ORIGIN in the runpath.
+#
+# Note that this does nothing when shared libraries are not used.
+function(setup_shared_library target version)
+  if (XMLWRAPP_SHARED)
+    # Construct XMLWRAPP_USE_DLL or XSLTWRAPP_USE_DLL symbol name.
+    string(TOUPPER "${target}_USE_DLL" use_dll_symbol)
+    target_compile_definitions(${target}
+      PRIVATE
+        HAVE_VISIBILITY
+      INTERFACE
+        ${use_dll_symbol}
+    )
+
+    # Set SOVERSION to the major VERSION component.
+    string(REPLACE "." ";" version_as_list ${version})
+    list(GET version_as_list 0 soversion)
+
+    set(output_name "${target}")
+    if( XMLWRAPP_NAME_PREFIX )
+      set(output_name "${XMLWRAPP_NAME_PREFIX}${output_name}")
+    endif()
+    if( XMLWRAPP_NAME_SUFFIX )
+      set(output_name "${output_name}${XMLWRAPP_NAME_SUFFIX}")
+    endif()
+
+    set_target_properties(${target} PROPERTIES
+      OUTPUT_NAME ${output_name}
+      BUILD_RPATH_USE_ORIGIN ON
+      DEFINE_SYMBOL "DLL_EXPORT"
+      CXX_VISIBILITY_PRESET hidden
+      VISIBILITY_INLINES_HIDDEN ON
+      VERSION ${version}
+      SOVERSION ${soversion}
+    )
+  endif()
+endfunction()
+
 add_library(xmlwrapp ${XMLWRAPP_LIB_TYPE})
 target_sources(xmlwrapp
   PRIVATE
@@ -41,9 +82,11 @@ target_link_libraries(xmlwrapp
   PUBLIC
     ${LIBXML2_LIBRARIES}
 )
-set_target_properties(xmlwrapp PROPERTIES VERSION 6.0.0 SOVERSION 6)
+setup_shared_library(xmlwrapp 6.0.0)
 install (TARGETS xmlwrapp EXPORT XmlwrappTargets DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
+add_library(xmlwrapp::xmlwrapp ALIAS xmlwrapp)
+
 if( XMLWRAPP_WITH_LIBXSLT )
   add_library(xsltwrapp ${XMLWRAPP_LIB_TYPE})
   target_sources(xsltwrapp
@@ -71,6 +114,8 @@ if( XMLWRAPP_WITH_LIBXSLT )
       ${LIBXSLT_LIBRARIES}
       ${LIBEXSLT_LIBRARIES}
   )
-  set_target_properties(xsltwrapp PROPERTIES VERSION 4.0.0 SOVERSION 4)
+  setup_shared_library(xsltwrapp 4.0.0)
   install (TARGETS xsltwrapp EXPORT XmlwrappTargets DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+  add_library(xmlwrapp::xsltwrapp ALIAS xsltwrapp)
 endif( XMLWRAPP_WITH_LIBXSLT )