CMake: Handle INPUT_foo values when detecting dirty builds

Before this change, the dirty feature code only checked for
differences between FEATURE_foo and QT_FEATURE_foo, without taking
into account modified INPUT_foo values that might passed via the
configure script.
This led to issues in certain scenarios when reconfiguring with the
configure script.

For example configuring with -gui / -DINPUT_gui=ON and then with
-no-gui / -DINPUT_gui=OFF would fail saying
  'Feature "widgets": Forcing to "ON" breaks its condition'

This happens because the widgets feature depends on gui being
available, but because INPUT_gui modifications don't trigger the dirty
feature re-eval code, we don't recompute the value of widgets.

Extract the code that takes into account the INPUT_foo variables into
a separate function, and use it both when computing feature values and
also when detecting dirty features.

This means any non-matching INPUT_foo variables will now also trigger
dirty feature checking.

Use the same function to replace the duplicate code we have to early
initialize the developer-build, no-prefix and pkg-config features.

Pick-to: 6.6
Task-number: QTBUG-112957
Change-Id: I775cf70b48291a659b0fecf7cb9570ec12735bca
Reviewed-by: Alexey Edelev <[email protected]>

3 files changed, 30 insertions, 45 deletions

diff --git a/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake b/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
index 1067e01e835..dda9f8f0939 100644
--- a/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
+++ b/cmake/QtBuildInternals/QtBuildInternalsConfig.cmake
@@ -105,6 +105,30 @@ endif()
 # build.
 include(QtPlatformSupport)
 
+# Set FEATURE_${feature} if INPUT_${feature} is set in certain circumstances.
+#
+# Needs to be in QtBuildInternalsConfig.cmake instead of QtFeature.cmake because it's used in
+# qt_build_internals_disable_pkg_config_if_needed.
+function(qt_internal_compute_feature_value_from_possible_input feature)
+    # If FEATURE_ is not defined try to use the INPUT_ variable to enable/disable feature.
+    # If FEATURE_ is defined and the configure script is being used (so
+    # QT_INTERNAL_CALLED_FROM_CONFIGURE is TRUE), ignore the FEATURE_ variable, and take into
+    # account the INPUT_ variable instead, because a command line argument takes priority over
+    # a pre-cached FEATURE_ variable.
+    if((NOT DEFINED FEATURE_${feature} OR QT_INTERNAL_CALLED_FROM_CONFIGURE)
+        AND DEFINED INPUT_${feature}
+        AND NOT "${INPUT_${feature}}" STREQUAL "undefined"
+        AND NOT "${INPUT_${feature}}" STREQUAL "")
+        if(INPUT_${feature})
+            set(FEATURE_${feature} ON)
+        else()
+            set(FEATURE_${feature} OFF)
+        endif()
+
+        set(FEATURE_${feature} "${FEATURE_${feature}}" PARENT_SCOPE)
+    endif()
+endfunction()
+
 function(qt_build_internals_disable_pkg_config_if_needed)
     # pkg-config should not be used by default on Darwin and Windows platforms (and QNX), as defined
     # in the qtbase/configure.json. Unfortunately by the time the feature is evaluated there are
@@ -131,16 +155,7 @@ function(qt_build_internals_disable_pkg_config_if_needed)
     endif()
 
     # Features won't have been evaluated yet if this is the first run, have to evaluate this here
-    if((NOT DEFINED "FEATURE_pkg_config" OR QT_INTERNAL_CALLED_FROM_CONFIGURE)
-            AND DEFINED INPUT_pkg_config
-            AND NOT "${INPUT_pkg_config}" STREQUAL "undefined"
-            AND NOT "${INPUT_pkg_config}" STREQUAL "")
-        if(INPUT_pkg_config)
-            set(FEATURE_pkg_config ON)
-        else()
-            set(FEATURE_pkg_config OFF)
-        endif()
-    endif()
+    qt_internal_compute_feature_value_from_possible_input(pkg_config)
 
     # If user explicitly specified a value for the feature, honor it, even if it might break
     # the build.
diff --git a/cmake/QtFeature.cmake b/cmake/QtFeature.cmake
index 77b91e077cb..207abd58c97 100644
--- a/cmake/QtFeature.cmake
+++ b/cmake/QtFeature.cmake
@@ -410,21 +410,7 @@ function(qt_evaluate_feature feature)
         qt_evaluate_config_expression(emit_if ${arg_EMIT_IF})
     endif()
 
-    # If FEATURE_ is not defined try to use the INPUT_ variable to enable/disable feature.
-    # If FEATURE_ is defined and the configure script is being used (so
-    # QT_INTERNAL_CALLED_FROM_CONFIGURE is TRUE), ignore the FEATURE_ variable, and take into
-    # account the INPUT_ variable instead, because a command line argument takes priority over
-    # a pre-cached FEATURE_ variable.
-    if((NOT DEFINED FEATURE_${feature} OR QT_INTERNAL_CALLED_FROM_CONFIGURE)
-        AND DEFINED INPUT_${feature}
-        AND NOT "${INPUT_${feature}}" STREQUAL "undefined"
-        AND NOT "${INPUT_${feature}}" STREQUAL "")
-        if(INPUT_${feature})
-            set(FEATURE_${feature} ON)
-        else()
-            set(FEATURE_${feature} OFF)
-        endif()
-    endif()
+    qt_internal_compute_feature_value_from_possible_input("${feature}")
 
     # Warn about a feature which is not emitted, but the user explicitly provided a value for it.
     if(NOT emit_if AND DEFINED FEATURE_${feature})
@@ -889,6 +875,8 @@ function(qt_internal_detect_dirty_features)
         message(STATUS "Checking for feature set changes")
         set_property(GLOBAL PROPERTY _qt_feature_clean TRUE)
         foreach(feature ${QT_KNOWN_FEATURES})
+            qt_internal_compute_feature_value_from_possible_input("${feature}")
+
             if(DEFINED "FEATURE_${feature}" AND
                 NOT "${QT_FEATURE_${feature}}" STREQUAL "${FEATURE_${feature}}")
                 message("    '${feature}' was changed from ${QT_FEATURE_${feature}} "
diff --git a/cmake/QtSetup.cmake b/cmake/QtSetup.cmake
index dfad3e77061..71d7e7200e9 100644
--- a/cmake/QtSetup.cmake
+++ b/cmake/QtSetup.cmake
@@ -17,29 +17,11 @@ endif()
 # Pre-calculate the developer_build feature if it's set by the user via the INPUT_developer_build
 # variable when using the configure script. When not using configure, don't take the INPUT variable
 # into account, so that users can toggle the feature directly in the cache or via IDE.
-if((NOT DEFINED FEATURE_developer_build OR QT_INTERNAL_CALLED_FROM_CONFIGURE)
-        AND DEFINED INPUT_developer_build
-        AND NOT "${INPUT_developer_build}" STREQUAL "undefined"
-        AND NOT "${INPUT_developer_build}" STREQUAL "")
-    if(INPUT_developer_build)
-        set(FEATURE_developer_build ON)
-    else()
-        set(FEATURE_developer_build OFF)
-    endif()
-endif()
+qt_internal_compute_feature_value_from_possible_input(developer_build)
 
 # Pre-calculate the no_prefix feature if it's set by configure via INPUT_no_prefix.
 # This needs to be done before qtbase/configure.cmake is processed.
-if((NOT DEFINED FEATURE_no_prefix OR QT_INTERNAL_CALLED_FROM_CONFIGURE)
-        AND DEFINED INPUT_no_prefix
-        AND NOT "${INPUT_no_prefix}" STREQUAL "undefined"
-        AND NOT "${INPUT_no_prefix}" STREQUAL "")
-    if(INPUT_no_prefix)
-        set(FEATURE_no_prefix ON)
-    else()
-        set(FEATURE_no_prefix OFF)
-    endif()
-endif()
+qt_internal_compute_feature_value_from_possible_input(no_prefix)
 
 set(_default_build_type "Release")
 if(FEATURE_developer_build)