Fix assumptions that CMAKE_INSTALL_*DIR variables are relative

The CMAKE_INSTALL_*DIR variables are allowed to be absolute paths, which allows
libraries and headers to be installed into separate prefixes. This means they
cannot be naively concatenated with CMAKE_INSTALL_PREFIX. If an absolute path
is needed, CMAKE_INSTALL_FULL_*DIR should be used, while more complicated
handling is required to keep ${prefix} interpolation in pkg-config files in
the case where CMAKE_INSTALL_*DIR is relative.

Signed-off-by: Ben Wolsieffer <[email protected]>

CMakeLists.txt

@@ -312,6 +312,16 @@ install(
   COMPONENT dev)
 
 # Generate Pkg-Config file
+if(IS_ABSOLUTE "${CMAKE_INSTALL_INCLUDEDIR}")
+  set(CYCLONEDDS_PKG_CONFIG_INCLUDEDIR "${CMAKE_INSTALL_INCLUDEDIR}")
+else()
+  set(CYCLONEDDS_PKG_CONFIG_INCLUDEDIR "\${prefix}/${CMAKE_INSTALL_INCLUDEDIR}")
+endif()
+if(IS_ABSOLUTE "${CMAKE_INSTALL_LIBDIR}")
+  set(CYCLONEDDS_PKG_CONFIG_LIBDIR "${CMAKE_INSTALL_LIBDIR}")
+else()
+  set(CYCLONEDDS_PKG_CONFIG_LIBDIR "\${prefix}/${CMAKE_INSTALL_LIBDIR}")
+endif()
 configure_file(
   "PkgConfig.pc.in"
   "${PROJECT_NAME}.pc"

PkgConfig.pc.in

@@ -1,6 +1,6 @@
 prefix=@CMAKE_INSTALL_PREFIX@
-includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
-libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
+includedir=@CYCLONEDDS_PKG_CONFIG_INCLUDEDIR@
+libdir=@CYCLONEDDS_PKG_CONFIG_LIBDIR@
 
 Name: @PROJECT_NAME@
 Description: Eclipse Cyclone DDS library

ports/freertos-posix/freertos-sim.cmake.in

@@ -17,8 +17,8 @@
 set(CMAKE_C_COMPILER "@CMAKE_C_COMPILER@")
 set(CMAKE_CXX_COMPILER "@CMAKE_CXX_COMPILER@")
 
-set(include_path "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@")
-set(library_path "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@")
+set(include_path "@CMAKE_INSTALL_FULL_INCLUDEDIR@")
+set(library_path "@CMAKE_INSTALL_FULL_LIBDIR@")
 
 set(CMAKE_C_FLAGS "-I${include_path} -Dmain=@ENTRYPOINT@ -m32")
 set(CMAKE_EXE_LINKER_FLAGS "-L${library_path}")