vcpkg_fixup_pkgconfig: Move definition of SYSTEM_LIBRARIES to vcpkg_c…

…ommon_definitions

To correctly validate installed pkg-config files, vcpkg_fixup_pkgconfig needs to know
for each platform which libraries are not managed by vcpkg. This commits improve this
definitions for all the triplet supported by vcpkg, and move this definition to vcpkg_common_definitions
in a way that permit custom triplets to overload its value.

scripts/cmake/vcpkg_common_definitions.cmake

@@ -16,6 +16,7 @@
 ## VCPKG_TARGET_IMPORT_LIBRARY_SUFFIX       import library suffix for target (same as CMAKE_IMPORT_LIBRARY_SUFFIX)
 ## VCPKG_FIND_LIBRARY_PREFIXES              target dependent prefixes used for find_library calls in portfiles
 ## VCPKG_FIND_LIBRARY_SUFFIXES              target dependent suffixes used for find_library calls in portfiles
+## VCPKG_SYSTEM_LIBRARIES                   list of libraries are provide by the toolchain and are not managed by vcpkg
 ## ```
 ##
 ## CMAKE_STATIC_LIBRARY_(PREFIX|SUFFIX), CMAKE_SHARED_LIBRARY_(PREFIX|SUFFIX) and CMAKE_IMPORT_LIBRARY_(PREFIX|SUFFIX) are defined for the target
@@ -111,3 +112,22 @@ set(CMAKE_IMPORT_LIBRARY_PREFIX "${VCPKG_TARGET_IMPORT_LIBRARY_SUFFIX}")
 
 set(CMAKE_FIND_LIBRARY_SUFFIXES "${VCPKG_FIND_LIBRARY_SUFFIXES}" CACHE INTERNAL "") # Required by find_library
 set(CMAKE_FIND_LIBRARY_PREFIXES "${VCPKG_FIND_LIBRARY_PREFIXES}" CACHE INTERNAL "") # Required by find_library
+
+# Append platform libraries to VCPKG_SYSTEM_LIBRARIES
+# The variable are just appended to permit to custom triplets define the variable
+
+# Platforms with libdl
+if(VCPKG_TARGET_IS_LINUX OR VCPKG_TARGET_IS_ANDROID OR VCPKG_TARGET_IS_OSX)
+    list(APPEND VCPKG_SYSTEM_LIBRARIES dl)
+endif()
+
+# Platforms with libm
+if(VCPKG_TARGET_IS_LINUX OR VCPKG_TARGET_IS_ANDROID OR VCPKG_TARGET_IS_FREEBSD)
+    list(APPEND VCPKG_SYSTEM_LIBRARIES m)
+endif()
+
+# Windows system libs
+if(VCPKG_TARGET_IS_WINDOWS)
+    list(APPEND VCPKG_SYSTEM_LIBRARIES wsock32)
+    list(APPEND VCPKG_SYSTEM_LIBRARIES ws2_32)
+endif()

scripts/cmake/vcpkg_fixup_pkgconfig.cmake

@@ -194,8 +194,8 @@ endfunction()
 function(vcpkg_fixup_pkgconfig)
     cmake_parse_arguments(_vfpkg "" "" "RELEASE_FILES;DEBUG_FILES;SYSTEM_LIBRARIES;SYSTEM_PACKAGES;IGNORE_FLAGS" ${ARGN})
 
-    if(VCPKG_TARGET_IS_LINUX)
-        list(APPEND _vfpkg_SYSTEM_LIBRARIES -ldl -lm)
+    if(VCPKG_SYSTEM_LIBRARIES)
+        list(APPEND _vfpkg_SYSTEM_LIBRARIES ${VCPKG_SYSTEM_LIBRARIES})
     endif()
     message(STATUS "Fixing pkgconfig")
     if(_vfpkg_UNPARSED_ARGUMENTS)