From 8826f136a9664bc0839cf84fc0eaf28cde1e954b Mon Sep 17 00:00:00 2001
From: Windel Bouwman <windel@windel.nl>
Date: Sun, 4 Sep 2022 19:18:14 +0200
Subject: [PATCH] Use imported target for res_tool during cross compilation.
 (#865)

---
 corelib/src/CMakeLists.txt                | 29 ++-------
 utilite/CMakeLists.txt                    |  4 +-
 utilite/resource_generator/CMakeLists.txt | 77 +++++++++++++++--------
 3 files changed, 57 insertions(+), 53 deletions(-)

diff --git a/corelib/src/CMakeLists.txt b/corelib/src/CMakeLists.txt
index f99d5123a3..ae087af189 100644
--- a/corelib/src/CMakeLists.txt
+++ b/corelib/src/CMakeLists.txt
@@ -725,29 +725,12 @@ endforeach(arg ${RESOURCES})
 #MESSAGE(STATUS "RESOURCES = ${RESOURCES}")
 #MESSAGE(STATUS "RESOURCES_HEADERS = ${RESOURCES_HEADERS}")
 
-IF(ANDROID OR IOS)
-
-   IF(NOT RTABMAP_RES_TOOL)
-      find_host_program(RTABMAP_RES_TOOL rtabmap-res_tool PATHS ${PROJECT_BINARY_DIR}/../bin)
-      IF(NOT RTABMAP_RES_TOOL)
-         MESSAGE( FATAL_ERROR "RTABMAP_RES_TOOL is not defined (it is the path to \"rtabmap-res_tool\" application created by a non-Android build)." )
-      ENDIF(NOT RTABMAP_RES_TOOL)
-   ENDIF(NOT RTABMAP_RES_TOOL)
-
-   ADD_CUSTOM_COMMAND(
-      OUTPUT ${RESOURCES_HEADERS}
-      COMMAND ${RTABMAP_RES_TOOL} -n rtabmap -p ${CMAKE_CURRENT_BINARY_DIR} ${RESOURCES}
-      COMMENT "[Creating resources]"
-      DEPENDS ${RESOURCES}
-   )
-ELSE()
-   ADD_CUSTOM_COMMAND(
-      OUTPUT ${RESOURCES_HEADERS}
-      COMMAND ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/rtabmap-res_tool -n rtabmap -p ${CMAKE_CURRENT_BINARY_DIR} ${RESOURCES}
-      COMMENT "[Creating resources]"
-      DEPENDS ${RESOURCES} res_tool
-   )
-ENDIF()
+ADD_CUSTOM_COMMAND(
+	OUTPUT ${RESOURCES_HEADERS}
+	COMMAND res_tool -n rtabmap -p ${CMAKE_CURRENT_BINARY_DIR} ${RESOURCES}
+	COMMENT "[Creating resources]"
+	DEPENDS ${RESOURCES}
+)
 
 ####################################
 # Generate resources files END
diff --git a/utilite/CMakeLists.txt b/utilite/CMakeLists.txt
index 39caf123f0..b152c0f719 100644
--- a/utilite/CMakeLists.txt
+++ b/utilite/CMakeLists.txt
@@ -7,6 +7,4 @@ ENDIF(UNIX AND NOT ANDROID)
 
 ADD_SUBDIRECTORY( src )
 
-IF(NOT MOBILE_BUILD)
-   ADD_SUBDIRECTORY( resource_generator )
-ENDIF(NOT MOBILE_BUILD)
+ADD_SUBDIRECTORY( resource_generator )
diff --git a/utilite/resource_generator/CMakeLists.txt b/utilite/resource_generator/CMakeLists.txt
index 40489b1404..a41de3bfbf 100644
--- a/utilite/resource_generator/CMakeLists.txt
+++ b/utilite/resource_generator/CMakeLists.txt
@@ -1,28 +1,51 @@
 
-SET(SRC_FILES
-    main.cpp
-)
-
-SET(INCLUDE_DIRS
-    ../include
-)
-
-# Make sure the compiler can find include files from our library.
-INCLUDE_DIRECTORIES(${INCLUDE_DIRS})
-
-# Add binary called "resource_tool" that is built from the source file "main.cpp".
-# The extension is automatically found.
-ADD_EXECUTABLE(res_tool ${SRC_FILES})
-TARGET_LINK_LIBRARIES(res_tool rtabmap_utilite)
- 
-SET_TARGET_PROPERTIES(
-res_tool 
-PROPERTIES
- VERSION ${UTILITE_VERSION} 
- SOVERSION ${UTILITE_VERSION}
- OUTPUT_NAME ${PROJECT_PREFIX}-res_tool
-)
-
-INSTALL(TARGETS res_tool
-		RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT runtime
-		BUNDLE DESTINATION "${CMAKE_BUNDLE_LOCATION}" COMPONENT runtime)
\ No newline at end of file
+if (CMAKE_CROSSCOMPILING OR ANDROID OR IOS)
+    # See this page about tools being required in the build:
+    # https://gitlab.kitware.com/cmake/community/-/wikis/doc/cmake/CrossCompiling#using-executables-in-the-build-created-during-the-build
+
+    # Some ideas there were used, not all.
+    # The target named 'res_tool' can be used elsewhere in all cases, when cross compiling or not.
+
+    IF(NOT RTABMAP_RES_TOOL)
+        FIND_PROGRAM(RTABMAP_RES_TOOL  ${PROJECT_PREFIX}-res_tool)
+        IF(NOT RTABMAP_RES_TOOL)
+            MESSAGE( FATAL_ERROR "RTABMAP_RES_TOOL is not defined (it is the path to \"rtabmap-res_tool\" application created by a non-Android build)." )
+        ENDIF(NOT RTABMAP_RES_TOOL)
+    ENDIF()
+
+    MESSAGE(STATUS "Using res_tool at ${RTABMAP_RES_TOOL}")
+
+    ADD_EXECUTABLE(res_tool IMPORTED GLOBAL)
+    SET_TARGET_PROPERTIES(res_tool PROPERTIES IMPORTED_LOCATION "${RTABMAP_RES_TOOL}")
+
+else()
+
+    SET(SRC_FILES
+        main.cpp
+    )
+
+    SET(INCLUDE_DIRS
+        ../include
+    )
+
+    # Make sure the compiler can find include files from our library.
+    INCLUDE_DIRECTORIES(${INCLUDE_DIRS})
+
+    # Add binary called "resource_tool" that is built from the source file "main.cpp".
+    # The extension is automatically found.
+    ADD_EXECUTABLE(res_tool ${SRC_FILES})
+    TARGET_LINK_LIBRARIES(res_tool rtabmap_utilite)
+    
+    SET_TARGET_PROPERTIES(
+    res_tool 
+    PROPERTIES
+    VERSION ${UTILITE_VERSION} 
+    SOVERSION ${UTILITE_VERSION}
+    OUTPUT_NAME ${PROJECT_PREFIX}-res_tool
+    )
+
+    INSTALL(TARGETS res_tool
+            RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}" COMPONENT runtime
+            BUNDLE DESTINATION "${CMAKE_BUNDLE_LOCATION}" COMPONENT runtime)
+
+endif()