Private dependencies are not propagated to other targets in generated install layout (#5581)

* transfering private dependencies as runtime dependencies for the generated targets in the install layout

Signed-off-by: Esteban Papp <81431996+amznestebanpapp@users.noreply.github.com>

* Update cmake/Platform/Common/Install_common.cmake

Signed-off-by: Esteban Papp <81431996+amznestebanpapp@users.noreply.github.com>

Co-authored-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>

* Update cmake/Platform/Common/Install_common.cmake

Signed-off-by: Esteban Papp <81431996+amznestebanpapp@users.noreply.github.com>

Co-authored-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>

Co-authored-by: lumberyard-employee-dm <56135373+lumberyard-employee-dm@users.noreply.github.com>

cmake/Platform/Common/Install_common.cmake

@@ -167,18 +167,16 @@ function(ly_setup_target OUTPUT_CONFIGURED_TARGET ALIAS_TARGET_NAME absolute_tar
     endforeach()
     list(JOIN INCLUDE_DIRECTORIES_PLACEHOLDER "\n" INCLUDE_DIRECTORIES_PLACEHOLDER)
 
-    string(REPEAT " " 8 PLACEHOLDER_INDENT)
-    get_target_property(RUNTIME_DEPENDENCIES_PLACEHOLDER ${TARGET_NAME} MANUALLY_ADDED_DEPENDENCIES)
-    if(RUNTIME_DEPENDENCIES_PLACEHOLDER) # not found properties return the name of the variable with a "-NOTFOUND" at the end, here we set it to empty if not found
-        set(RUNTIME_DEPENDENCIES_PLACEHOLDER "${PLACEHOLDER_INDENT}${RUNTIME_DEPENDENCIES_PLACEHOLDER}")
-        list(JOIN RUNTIME_DEPENDENCIES_PLACEHOLDER "\n${PLACEHOLDER_INDENT}" RUNTIME_DEPENDENCIES_PLACEHOLDER)
-    else()
-        unset(RUNTIME_DEPENDENCIES_PLACEHOLDER)
-    endif()
-
     string(REPEAT " " 12 PLACEHOLDER_INDENT)
     get_property(interface_build_dependencies_props TARGET ${TARGET_NAME} PROPERTY LY_DELAYED_LINK)
     unset(INTERFACE_BUILD_DEPENDENCIES_PLACEHOLDER)
+    # We can have private build dependencies that contains direct or indirect runtime dependencies.
+    # Since imported targets cannot contain build dependencies, we need another way to propagate the runtime dependencies.
+    # We dont want to put such dependencies in the interface because a user can mistakenly use a symbol that is not available 
+    # when using the engine from source (and that the author of the target didn't want to set public). 
+    # To overcome this, we will actually expose the private build dependencies as runtime dependencies. Our runtime dependency
+    # algorithm will walk recursively also through static libraries and will only copy binaries to the output.
+    unset(RUNTIME_DEPENDENCIES_PLACEHOLDER) 
     if(interface_build_dependencies_props)
         cmake_parse_arguments(build_deps "" "" "PRIVATE;PUBLIC;INTERFACE" ${interface_build_dependencies_props})
         # Interface and public dependencies should always be exposed
@@ -191,6 +189,8 @@ function(ly_setup_target OUTPUT_CONFIGURED_TARGET ALIAS_TARGET_NAME absolute_tar
         if("${target_type}" STREQUAL "STATIC_LIBRARY")
             set(build_deps_target "${build_deps_target};${build_deps_PRIVATE}")
         endif()
+        # But we will also pass the private dependencies as runtime dependencies (note the comment above)
+        set(RUNTIME_DEPENDENCIES_PLACEHOLDER ${build_deps_PRIVATE})
         foreach(build_dependency IN LISTS build_deps_target)
             # Skip wrapping produced when targets are not created in the same directory
             if(build_dependency)
@@ -200,6 +200,18 @@ function(ly_setup_target OUTPUT_CONFIGURED_TARGET ALIAS_TARGET_NAME absolute_tar
     endif()
     list(JOIN INTERFACE_BUILD_DEPENDENCIES_PLACEHOLDER "\n" INTERFACE_BUILD_DEPENDENCIES_PLACEHOLDER)
 
+    string(REPEAT " " 8 PLACEHOLDER_INDENT)
+    get_target_property(manually_added_dependencies ${TARGET_NAME} MANUALLY_ADDED_DEPENDENCIES)
+    if(manually_added_dependencies) # not found properties return the name of the variable with a "-NOTFOUND" at the end, here we set it to empty if not found
+        list(APPEND RUNTIME_DEPENDENCIES_PLACEHOLDER ${manually_added_dependencies})
+    endif()
+    if(RUNTIME_DEPENDENCIES_PLACEHOLDER)   
+        set(RUNTIME_DEPENDENCIES_PLACEHOLDER "${PLACEHOLDER_INDENT}${RUNTIME_DEPENDENCIES_PLACEHOLDER}")
+        list(JOIN RUNTIME_DEPENDENCIES_PLACEHOLDER "\n${PLACEHOLDER_INDENT}" RUNTIME_DEPENDENCIES_PLACEHOLDER)
+    else()
+        unset(RUNTIME_DEPENDENCIES_PLACEHOLDER)
+    endif()
+
     string(REPEAT " " 8 PLACEHOLDER_INDENT)
     # If a target has an LY_PROJECT_NAME property, forward that property to new target
     get_target_property(target_project_association ${TARGET_NAME} LY_PROJECT_NAME)