ports/cmake: fix up of pkg-config file template processing with Libs.…

…private

This is based on the change that went into

	microsoft/vcpkg#42601

I added some, removed some.



git-svn-id: svn://scm.orgis.org/mpg123/trunk@5462 35dc7657-300d-0410-a2e5-dc2837fedb53

NEWS

@@ -7,6 +7,7 @@
 - libmpg123:
 -- Un-break DLL builds that need I/O functions defined in libmpg123.c
    (like mpg123_open(), bug 374).
+- ports/cmake: More fixup to also produce .pc files with Libs.private.
 
 1.32.9
 ------

ports/cmake/src/CMakeLists.txt

@@ -41,6 +41,14 @@ function(check_m)
     check_function_exists(sin HAVE_M)
 endfunction(check_m)
 check_m()
+# Cargo coding the check if there is a library rt, possibly providing
+# a canary symbol. I am not sure if this logic really mirrors what
+# autotools does.
+function(check_rt)
+    set(CMAKE_REQUIRED_LIBRARIES rt)
+    check_function_exists(clock_gettime HAVE_RT)
+endfunction(check_rt)
+check_rt()
 
 check_function_exists(atoll HAVE_ATOLL)
 check_function_exists(getaddrinfo HAVE_IPV6)
@@ -450,3 +458,7 @@ if(UNIX AND NOT PORTABLE_API)
 endif()
 
 configure_file(config.cmake.h.in config.h)
+
+set(LIBMPG123_LIBS "${LIBMPG123_LIBS}" PARENT_SCOPE)
+set(LIBOUT123_LIBS "${LIBOUT123_LIBS}" PARENT_SCOPE)
+set(LIBSYN123_LIBS "${LIBSYN123_LIBS}" PARENT_SCOPE)

ports/cmake/src/libmpg123/CMakeLists.txt

@@ -235,6 +235,13 @@ else()
     target_sources(${TARGET} PRIVATE ${PLATFORM_SOURCES})
 endif()
 
+if(HAVE_M)
+    string(APPEND LIBMPG123_LIBS " -lm")
+endif()
+if(WANT_WIN32_UNICODE)
+    string(APPEND LIBMPG123_LIBS " -lshlwapi")
+endif()
+set(LIBMPG123_LIBS "${LIBMPG123_LIBS}" PARENT_SCOPE)
 target_link_libraries(${TARGET} PRIVATE
     $<$<BOOL:${HAVE_M}>:m>
     $<$<BOOL:${WANT_WIN32_UNICODE}>:shlwapi>)

ports/cmake/src/libout123/CMakeLists.txt

@@ -18,9 +18,24 @@ add_library(${TARGET}
 
 set_target_properties(${TARGET} PROPERTIES OUTPUT_NAME out123)
 
+if(HAVE_UNIX_DL)
+    string(APPEND LIBOUT123_LIBS " -ldl")
+endif()
+if(HAVE_M)
+    string(APPEND LIBOUT123_LIBS " -lm")
+endif()
+if(HAVE_RT)
+    string(APPEND LIBOUT123_LIBS " -lrt")
+endif()
+if(WANT_WIN32_UNICODE)
+    string(APPEND LIBOUT123_LIBS " -lshlwapi")
+endif()
+set(LIBOUT123_LIBS "${LIBOUT123_LIBS}" PARENT_SCOPE)
 target_link_libraries(${TARGET} PRIVATE
     $<TARGET_NAME_IF_EXISTS:defaultmodule>
     $<$<BOOL:${HAVE_UNIX_DL}>:dl>
+    $<$<BOOL:${HAVE_M}>:m>
+    $<$<BOOL:${HAVE_RT}>:rt>
     $<$<BOOL:${WANT_WIN32_UNICODE}>:shlwapi>)
 
 target_include_directories(${TARGET} INTERFACE

ports/cmake/src/libsyn123/CMakeLists.txt

@@ -19,9 +19,12 @@ target_include_directories(${TARGET} INTERFACE
     "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>"
     "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
 
+if(HAVE_M)
+    string(APPEND LIBSYN123_LIBS " -lm")
+endif()
+set(LIBSYN123_LIBS "${LIBSYN123_LIBS}" PARENT_SCOPE)
 target_link_libraries(${TARGET} PRIVATE
-    $<$<BOOL:${HAVE_M}>:m>
-    $<$<BOOL:${WANT_WIN32_UNICODE}>:shlwapi>)
+    $<$<BOOL:${HAVE_M}>:m>)
 
 install(TARGETS ${TARGET} EXPORT targets
     ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}/"