Fix assumptions that CMAKE_INSTALL_*DIR paths are relative. (#2779)

When an absolute path is desired, the CMAKE_INSTALL_FULL_*DIR variables should
be used instead of concatenating with CMAKE_INSTALL_PREFIX. Special handling is
also needed for pkg-config files.

CMakeLists.txt

@@ -166,11 +166,11 @@ message (STATUS "----------------------------------------\n")
 # 2. In the generation of cmake/setup.sh from cmake/setup.sh.in
 set(GAZEBO_DEFAULT_MASTER_HOST localhost)
 set(GAZEBO_DEFAULT_MASTER_PORT 11345)
-set(GAZEBO_PLUGIN_PATH ${CMAKE_INSTALL_PREFIX}/${LIB_INSTALL_DIR}/gazebo-${GAZEBO_MAJOR_VERSION}/plugins)
+set(GAZEBO_PLUGIN_PATH ${CMAKE_INSTALL_FULL_LIBDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/plugins)
 FILE(TO_NATIVE_PATH "${GAZEBO_PLUGIN_PATH}" GAZEBO_PLUGIN_PATH)
-set(GAZEBO_MODEL_PATH ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/models)
+set(GAZEBO_MODEL_PATH ${CMAKE_INSTALL_FULL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/models)
 FILE(TO_NATIVE_PATH "${GAZEBO_MODEL_PATH}" GAZEBO_MODEL_PATH)
-set(GAZEBO_RESOURCE_PATH ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION})
+set(GAZEBO_RESOURCE_PATH ${CMAKE_INSTALL_FULL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION})
 FILE(TO_NATIVE_PATH "${GAZEBO_RESOURCE_PATH}" GAZEBO_RESOURCE_PATH)
 set(GAZEBO_MODEL_DATABASE_URI http://models.gazebosim.org)
 set(OGRE_RESOURCE_PATH ${OGRE_PLUGINDIR})
@@ -332,15 +332,15 @@ else (build_errors)
   gz_install_includes("" ${PROJECT_BINARY_DIR}/gazebo/gazebo_config.h)
 
   configure_file(${CMAKE_SOURCE_DIR}/cmake/setup.sh.in ${PROJECT_BINARY_DIR}/setup.sh @ONLY)
-  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.sh DESTINATION ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/)
+  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.sh DESTINATION ${CMAKE_INSTALL_FULL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/)
   # Also install the setup.sh in an unversioned location
-  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.sh DESTINATION ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gazebo/)
+  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.sh DESTINATION ${CMAKE_INSTALL_FULL_DATAROOTDIR}/gazebo/)
 
   if (WIN32)
     configure_file(${CMAKE_SOURCE_DIR}/cmake/setup.bat.in ${PROJECT_BINARY_DIR}/setup.bat @ONLY)
-    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.bat DESTINATION ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.bat DESTINATION ${CMAKE_INSTALL_FULL_DATAROOTDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/)
     # Also install the setup.bat in an unversioned location
-    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.bat DESTINATION ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gazebo/)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/setup.bat DESTINATION ${CMAKE_INSTALL_FULL_DATAROOTDIR}/gazebo/)
   endif ()
 
   if (DEFINED CMAKE_CXX_FLAGS)
@@ -403,6 +403,10 @@ else (build_errors)
     set (Boost_PKGCONFIG_LIBS "${Boost_PKGCONFIG_LIBS} ${bname}")
   endforeach(b)
 
+  include(${gazebo_cmake_dir}/JoinPaths.cmake)
+  join_paths(pkgconfig_libdir "\${prefix}" "${CMAKE_INSTALL_LIBDIR}")
+  join_paths(pkgconfig_includedir "\${prefix}" "${CMAKE_INSTALL_INCLUDEDIR}")
+
   foreach (pkgconfig ${pkgconfig_files})
     configure_file(${CMAKE_SOURCE_DIR}/cmake/pkgconfig/${pkgconfig}.in ${CMAKE_CURRENT_BINARY_DIR}/cmake/pkgconfig/${pkgconfig}.pc @ONLY)
     install(FILES ${CMAKE_CURRENT_BINARY_DIR}/cmake/pkgconfig/${pkgconfig}.pc DESTINATION ${LIB_INSTALL_DIR}/pkgconfig COMPONENT pkgconfig)

cmake/JoinPaths.cmake

@@ -0,0 +1,23 @@
+# This module provides a function for joining paths
+# known from most languages
+#
+# SPDX-License-Identifier: (MIT OR CC0-1.0)
+# Copyright 2020 Jan Tojnar
+# https://github.com/jtojnar/cmake-snips
+#
+# Modelled after Python’s os.path.join
+# https://docs.python.org/3.7/library/os.path.html#os.path.join
+# Windows not supported
+function(join_paths joined_path first_path_segment)
+    set(temp_path "${first_path_segment}")
+    foreach(current_segment IN LISTS ARGN)
+        if(NOT ("${current_segment}" STREQUAL ""))
+            if(IS_ABSOLUTE "${current_segment}")
+                set(temp_path "${current_segment}")
+            else()
+                set(temp_path "${temp_path}/${current_segment}")
+            endif()
+        endif()
+    endforeach()
+    set(${joined_path} "${temp_path}" PARENT_SCOPE)
+endfunction()

cmake/gazebo-config.cmake.in

@@ -5,7 +5,7 @@ set(@PKG_NAME@_CONFIG_INCLUDED TRUE)
 set(@PKG_NAME@_VERSION @GAZEBO_VERSION@)
 set(@PKG_NAME@_MAJOR_VERSION @GAZEBO_MAJOR_VERSION@)
 
-set(@PKG_NAME@_PLUGIN_PATH "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins")
+set(@PKG_NAME@_PLUGIN_PATH "@CMAKE_INSTALL_FULL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins")
 
 # The media path contains the location on disk where images,
 # materials scripts, shaders, and other related resources are stored.
@@ -71,23 +71,23 @@ include (FindPkgConfig)
 # target_link_libraries(your_package @PKG_NAME@_PROTO_LIBRARIES)
 #
 set(@PKG_NAME@_PROTO_PATH
-  "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/gazebo/msgs/proto")
+  "@CMAKE_INSTALL_FULL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/gazebo/msgs/proto")
 find_library(gazebo_proto_msgs_lib gazebo_msgs
-  PATHS "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@" NO_DEFAULT_PATH)
+  PATHS "@CMAKE_INSTALL_FULL_LIBDIR@" NO_DEFAULT_PATH)
 list(APPEND @PKG_NAME@_PROTO_LIBRARIES ${gazebo_proto_msgs_lib})
 list(APPEND @PKG_NAME@_PROTO_INCLUDE_DIRS
-  "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/gazebo/msgs")
+  "@CMAKE_INSTALL_FULL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/gazebo/msgs")
 # End @PKG_NAME@_PROTO_PATH, @PKG_NAME@_PROTO_INCLUDE_DIRS, and
 # @PKG_NAME@_PROTO_LIBRARIES
 
-list(APPEND @PKG_NAME@_INCLUDE_DIRS @CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@)
-list(APPEND @PKG_NAME@_INCLUDE_DIRS @CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@)
+list(APPEND @PKG_NAME@_INCLUDE_DIRS @CMAKE_INSTALL_FULL_INCLUDEDIR@)
+list(APPEND @PKG_NAME@_INCLUDE_DIRS @CMAKE_INSTALL_FULL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@)
 
-list(APPEND @PKG_NAME@_LIBRARY_DIRS @CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@)
-list(APPEND @PKG_NAME@_LIBRARY_DIRS @CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins)
+list(APPEND @PKG_NAME@_LIBRARY_DIRS @CMAKE_INSTALL_FULL_LIBDIR@)
+list(APPEND @PKG_NAME@_LIBRARY_DIRS @CMAKE_INSTALL_FULL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins)
 
-list(APPEND @PKG_NAME@_CFLAGS -I@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@)
-list(APPEND @PKG_NAME@_CFLAGS -I@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@)
+list(APPEND @PKG_NAME@_CFLAGS -I@CMAKE_INSTALL_FULL_INCLUDEDIR@)
+list(APPEND @PKG_NAME@_CFLAGS -I@CMAKE_INSTALL_FULL_INCLUDEDIR@/gazebo-@GAZEBO_MAJOR_VERSION@)
 
 if (GAZEBO_HAS_BULLET)
   if (PKG_CONFIG_FOUND)
@@ -138,7 +138,7 @@ endif ()
 foreach(lib @PKG_LIBRARIES@)
   set(onelib "${lib}-NOTFOUND")
   find_library(onelib ${lib}
-    PATHS "@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@"
+    PATHS "@CMAKE_INSTALL_FULL_LIBDIR@"
     NO_DEFAULT_PATH
     )
   if(NOT onelib)
@@ -217,6 +217,6 @@ if (GAZEBO_HAS_IGNITION_FUEL_TOOLS)
   list(APPEND @PKG_NAME@_LIBRARIES ${IGNITION-FUEL_TOOLS_LIBRARIES})
 endif()
 
-list(APPEND @PKG_NAME@_LDFLAGS -Wl,-rpath,@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins)
-list(APPEND @PKG_NAME@_LDFLAGS -L@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@)
-list(APPEND @PKG_NAME@_LDFLAGS -L@CMAKE_INSTALL_PREFIX@/@CMAKE_INSTALL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins)
+list(APPEND @PKG_NAME@_LDFLAGS -Wl,-rpath,@CMAKE_INSTALL_FULL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins)
+list(APPEND @PKG_NAME@_LDFLAGS -L@CMAKE_INSTALL_FULL_LIBDIR@)
+list(APPEND @PKG_NAME@_LDFLAGS -L@CMAKE_INSTALL_FULL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins)

cmake/pkgconfig/gazebo.in

@@ -1,10 +1,10 @@
 prefix=@CMAKE_INSTALL_PREFIX@
-libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
-includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+libdir=@pkgconfig_libdir@
+includedir=@pkgconfig_includedir@
 
 Name: gazebo
 Description: Gazebo Libraries
 Version: @GAZEBO_VERSION_FULL@
 Requires: sdformat protobuf @TBB_PKG_CONFIG@ ignition-math4 ignition-msgs1 ignition-transport4 @IGNITION_FUEL_TOOLS_PKGCONFIG@
-Libs: -Wl,-rpath,${prefix}/@CMAKE_INSTALL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins -L${libdir} -L${prefix}/@CMAKE_INSTALL_LIBDIR@/gazebo-@GAZEBO_MAJOR_VERSION@/plugins -lgazebo_transport -lgazebo_physics -lgazebo_sensors -lgazebo_rendering -lgazebo_gui -lgazebo_client -lgazebo_msgs -lgazebo_common -lgazebo @Boost_PKGCONFIG_LIBS@ @APPLE_PKGCONFIG_LIBS@
+Libs: -Wl,-rpath,${libdir}/gazebo-@GAZEBO_MAJOR_VERSION@/plugins -L${libdir} -L${libdir}/gazebo-@GAZEBO_MAJOR_VERSION@/plugins -lgazebo_transport -lgazebo_physics -lgazebo_sensors -lgazebo_rendering -lgazebo_gui -lgazebo_client -lgazebo_msgs -lgazebo_common -lgazebo @Boost_PKGCONFIG_LIBS@ @APPLE_PKGCONFIG_LIBS@
 CFlags: -I${includedir}/gazebo-@GAZEBO_MAJOR_VERSION@ @Boost_PKGCONFIG_CFLAGS@ -std=c++11

cmake/pkgconfig/gazebo_ode.in

@@ -1,10 +1,10 @@
 prefix=@CMAKE_INSTALL_PREFIX@
-libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
-includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+libdir=@pkgconfig_libdir@
+includedir=@pkgconfig_includedir@
 
 Name: gazebo
 Description: Gazebo Exported ODE Libraries
 Version: @GAZEBO_VERSION_FULL@
 Requires:
-Libs: -Wl,-rpath,${prefix}/@CMAKE_INSTALL_LIBDIR@ -L${prefix}/@CMAKE_INSTALL_LIBDIR@ -lgazebo_ode
+Libs: -Wl,-rpath,${libdir} -L${libdir} -lgazebo_ode
 CFlags: -I${includedir}/gazebo-@GAZEBO_MAJOR_VERSION@

cmake/pkgconfig/gazebo_transport.in

@@ -1,6 +1,6 @@
 prefix=@CMAKE_INSTALL_PREFIX@
-libdir=${prefix}/@CMAKE_INSTALL_LIBDIR@
-includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
+libdir=@pkgconfig_libdir@
+includedir=@pkgconfig_includedir@
 
 Name: gazebo_transport
 Description: Gazebo Transport Library

plugins/CMakeLists.txt

@@ -161,7 +161,7 @@ set (DARTplugins
 )
 
 set(GAZEBO_PLUGIN_INSTALL_DIR
-  ${CMAKE_INSTALL_PREFIX}/${LIB_INSTALL_DIR}/gazebo-${GAZEBO_MAJOR_VERSION}/plugins/
+  ${CMAKE_INSTALL_FULL_LIBDIR}/gazebo-${GAZEBO_MAJOR_VERSION}/plugins/
 )
 
 add_library(TrackedVehiclePlugin SHARED TrackedVehiclePlugin.cc)