Revert "Revert "CMake: Fix usage of find_dependency()""

...and fix the build errors the original change caused.
This reverts commit 127fb8bb55.

Change-Id: I4006b32734a51c5d101dd73c957f81d2a0f84ba1
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

cmake/QtConfig.cmake.in

@@ -51,15 +51,13 @@ endif()
 
 # Find required dependencies, if any.
 include(CMakeFindDependencyMacro)
-set(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCIES_FOUND TRUE)
 if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@Dependencies.cmake")
     include("${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@Dependencies.cmake")
-endif()
+    if(NOT @INSTALL_CMAKE_NAMESPACE@_DEPENDENCIES_FOUND)
-if(NOT @INSTALL_CMAKE_NAMESPACE@_DEPENDENCIES_FOUND)
+        set(@INSTALL_CMAKE_NAMESPACE@_FOUND FALSE)
-    set(@INSTALL_CMAKE_NAMESPACE@_FOUND False)
+        message(FATAL_ERROR "Failed to find Qt Platform dependency: "
-    message(FATAL_ERROR
+            "${@INSTALL_CMAKE_NAMESPACE@_DEPENDENCY_NOT_FOUND_MESSAGE}")
-    "Failed to find Qt Platform dependency:
+    endif()
-    ${@INSTALL_CMAKE_NAMESPACE@_DEPENDENCY_NOT_FOUND_MESSAGE}")
 endif()
 
 foreach(module ${@INSTALL_CMAKE_NAMESPACE@_FIND_COMPONENTS})

cmake/QtConfigDependencies.cmake.in

@@ -1,3 +1,5 @@
+set(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCIES_FOUND FALSE)
+
 # note: _third_party_deps example: "ICU\\;1.0\\;i18n uc data;ZLIB\\;\\;"
 set(_third_party_deps "@third_party_deps@")
 
@@ -12,24 +14,24 @@ foreach(_target_dep ${_third_party_deps})
         list(APPEND find_package_args "${version}")
     endif()
 
+    # Already build an error message, because find_dependency calls return() on failure.
+    set(__@INSTALL_CMAKE_NAMESPACE@_message "\nPackage: ${pkg}")
+    if(version)
+        string(APPEND __@INSTALL_CMAKE_NAMESPACE@_message "\nVersion: ${version}")
+    endif()
+    if(components)
+        string(APPEND __@INSTALL_CMAKE_NAMESPACE@_message "\nComponents: ${components}")
+    endif()
+    set(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCY_NOT_FOUND_MESSAGE
+        "${__@INSTALL_CMAKE_NAMESPACE@_message}")
+
     if(components)
         string(REPLACE " " ";" components "${components}")
         find_dependency(${find_package_args} COMPONENTS ${components})
     else()
         find_dependency(${find_package_args})
     endif()
-
-    if (NOT ${pkg}_FOUND)
-        set(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCIES_FOUND FALSE)
-        set(__@INSTALL_CMAKE_NAMESPACE@_message "\nPackage: ${pkg}")
-        if(version)
-            string(APPEND __@INSTALL_CMAKE_NAMESPACE@_message "\nVersion: ${version}")
-        endif()
-        if(components)
-            string(APPEND __@INSTALL_CMAKE_NAMESPACE@_message "\nComponents: ${components}")
-        endif()
-        set(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCY_NOT_FOUND_MESSAGE
-            "${__@INSTALL_CMAKE_NAMESPACE@_message}")
-        return()
-    endif()
 endforeach()
+
+set(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCIES_FOUND TRUE)
+unset(@INSTALL_CMAKE_NAMESPACE@_DEPENDENCY_NOT_FOUND_MESSAGE)

cmake/QtModuleConfig.cmake.in

@@ -14,6 +14,12 @@ if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@@target@Dependenci
     include("${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@@target@Dependencies.cmake")
 endif()
 
+# If *ConfigDependencies.cmake exists, the variable value will be defined there.
+# Don't override it in that case.
+if(NOT DEFINED "@INSTALL_CMAKE_NAMESPACE@@target@_FOUND")
+    set("@INSTALL_CMAKE_NAMESPACE@@target@_FOUND" TRUE)
+endif()
+
 if (NOT QT_NO_CREATE_TARGETS)
     include("${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@@target@Targets.cmake")
     if(NOT QT_NO_CREATE_VERSIONLESS_TARGETS)
@@ -85,7 +91,6 @@ include(${_qt_@PROJECT_VERSION_MAJOR@_config_cmake_dir}/QtFeature.cmake)
 
 qt_make_features_available(@QT_CMAKE_EXPORT_NAMESPACE@::@target@)
 
-set("@INSTALL_CMAKE_NAMESPACE@@target@_FOUND" TRUE)
 if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@@target@Plugins.cmake")
     include("${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@@target@Plugins.cmake")
 endif()

cmake/QtModuleDependencies.cmake.in

@@ -1,11 +1,8 @@
 # Make sure @INSTALL_CMAKE_NAMESPACE@ is found before anything else.
+set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
 find_dependency(@INSTALL_CMAKE_NAMESPACE@ @PROJECT_VERSION@
     PATHS "${CMAKE_CURRENT_LIST_DIR}/.." ${QT_EXAMPLES_CMAKE_PREFIX_PATH} NO_DEFAULT_PATH
 )
-if (NOT @INSTALL_CMAKE_NAMESPACE@_FOUND)
-    set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
-    return()
-endif()
 
 # note: _third_party_deps example: "ICU\\;1.0\\;i18n uc data;ZLIB\\;\\;"
 set(_third_party_deps "@third_party_deps@")
@@ -25,11 +22,6 @@ foreach(_target_dep ${_third_party_deps})
     else()
         find_dependency(${find_package_args})
     endif()
-
-    if (NOT ${pkg}_FOUND)
-        set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
-        return()
-    endif()
 endforeach()
 
 # Find Qt tool package.
@@ -47,10 +39,15 @@ foreach(_target_dep ${_tool_deps})
     list(GET _target_dep 0 pkg)
     list(GET _target_dep 1 version)
 
-    find_dependency(${pkg} ${version})
+    unset(find_package_args)
-
+    if(${CMAKE_FIND_PACKAGE_NAME}_FIND_QUIETLY)
+        list(APPEND find_package_args QUIET)
+    endif()
+    if(${CMAKE_FIND_PACKAGE_NAME}_FIND_REQUIRED)
+        list(APPEND find_package_args REQUIRED)
+    endif()
+    find_package(${pkg} ${version} ${find_package_args})
     if (NOT ${pkg}_FOUND)
-        set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
         if(QT_HOST_PATH)
              set(CMAKE_PREFIX_PATH ${BACKUP_@target@_CMAKE_PREFIX_PATH})
              set(CMAKE_FIND_ROOT_PATH ${BACKUP_@target@_CMAKE_FIND_ROOT_PATH})
@@ -74,12 +71,7 @@ foreach(_target_dep ${_target_deps})
             PATHS "${CMAKE_CURRENT_LIST_DIR}/.." ${QT_EXAMPLES_CMAKE_PREFIX_PATH} NO_DEFAULT_PATH
         )
     endif()
-
-    if (NOT ${pkg}_FOUND)
-        set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
-        return()
-    endif()
 endforeach()
 
 set(_@QT_CMAKE_EXPORT_NAMESPACE@@target@_MODULE_DEPENDENCIES "@qt_module_dependencies@")
-
+set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND TRUE)

cmake/QtModuleToolsDependencies.cmake.in

@@ -1,4 +1,5 @@
 # Find "ModuleTools" dependencies, which are other ModuleTools packages.
+set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
 set(_tool_deps "@package_deps@")
 foreach(_target_dep ${_tool_deps})
     list(GET _target_dep 0 pkg)
@@ -7,10 +8,6 @@ foreach(_target_dep ${_tool_deps})
     if (NOT ${pkg}_FOUND)
         find_dependency(${pkg} ${version})
     endif()
-
-    if (NOT ${pkg}_FOUND)
-        set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND FALSE)
-        return()
-    endif()
 endforeach()
 
+set(@INSTALL_CMAKE_NAMESPACE@@target@_FOUND TRUE)

cmake/QtPluginDependencies.cmake.in

@@ -1,3 +1,5 @@
+set(@target@_FOUND FALSE)
+
 # note: _third_party_deps example: "ICU\\;1.0\\;i18n uc data;ZLIB\\;\\;"
 set(_third_party_deps "@third_party_deps@")
 
@@ -10,16 +12,11 @@ foreach(_target_dep ${_third_party_deps})
         list(APPEND find_package_args "${version}")
     endif()
 
-        if(components)
+    if(components)
-            string(REPLACE " " ";" components "${components}")
+        string(REPLACE " " ";" components "${components}")
-            find_dependency(${find_package_args} COMPONENTS ${components})
+        find_dependency(${find_package_args} COMPONENTS ${components})
-        else()
+    else()
-            find_dependency(${find_package_args})
+        find_dependency(${find_package_args})
-        endif()
-
-    if (NOT ${pkg}_FOUND)
-        set(@target@_FOUND FALSE)
-        return()
     endif()
 endforeach()
 
@@ -34,9 +31,6 @@ foreach(_target_dep ${_target_deps})
             PATHS @find_dependency_paths@ ${QT_EXAMPLES_CMAKE_PREFIX_PATH} NO_DEFAULT_PATH
         )
     endif()
-
-    if (NOT ${pkg}_FOUND)
-        set(@target@_FOUND FALSE)
-        return()
-    endif()
 endforeach()
+
+set(@target@_FOUND TRUE)