CMake: Add FindSlog2

Add FindSlog2 and use it in src/corelib/configure.cmake.

Change-Id: I7e6a696a49df568a41ed1224228ab608db2dbb0e
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>

cmake/FindSlog2.cmake

@@ -0,0 +1,19 @@
+# Find the Slog2 library
+
+# Will make the target Slog2::Slog2 available when found.
+
+find_library(Slog2_LIBRARY NAMES "slog2")
+find_path(Slog2_INCLUDE_DIR NAMES "sys/slog2.h" DOC "The Slog2 Include path")
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Slog2 DEFAULT_MSG Slog2_INCLUDE_DIR Slog2_LIBRARY)
+
+mark_as_advanced(Slog2_INCLUDE_DIR Slog2_LIBRARY)
+
+if(Slog2_FOUND)
+    add_library(__Slog2 IMPORTED)
+    target_link_libraries(__Slog2 INTERFACE ${Slog2_LIBRARY})
+    target_include_directories(__Slog2 INTERFACE ${Slog2_INCLUDE_DIR})
+
+    add_library(Slog2::Slog2 ALIAS __Slog2)
+endif()

src/corelib/configure.cmake

@@ -24,6 +24,8 @@ find_package(PCRE2)
 set_package_properties(PCRE2 PROPERTIES TYPE REQUIRED)
 find_package(PPS)
 set_package_properties(PPS PROPERTIES TYPE OPTIONAL)
+find_package(Slog2)
+set_package_properties(Slog2 PROPERTIES TYPE OPTIONAL)
 
 
 #### Tests
@@ -477,7 +479,7 @@ qt_feature("renameat2" PRIVATE
 )
 qt_feature("slog2" PRIVATE
     LABEL "slog2"
-    CONDITION libs.slog2 OR FIXME
+    CONDITION Slog2_FOUND
 )
 qt_feature("statx" PRIVATE
     LABEL "statx() in libc"

util/cmake/configurejson2cmake.py

@@ -74,6 +74,7 @@ def map_library(lib: str) -> Union[str, LibraryMapping, List[str]]:
        'pcre2': ['PCRE2', 'REQUIRED'],
        'posix_iconv': None,
        'pps': 'PPS',
+       'slog2': 'Slog2',
        'sun_iconv': None,
        'udev': 'Libudev',
        'vulkan': 'Vulkan',