CMakeProjectManager: Use CMAKE_HOME_DIRECTORY as source directory

The CMakeCache.txt file has CMAKE_HOME_DIRECTORY pointing to the
project source directory used to configure the project.

When importing a cmake build the CMAKE_HOME_DIRECTORY from
CMakeCache.txt might not point to the same CMakeLists.txt that was
opened as a project.

qt-cmake-standalone-test from Qt6 uses a CMake template project which
does a add_subdirectory with the test source directory, which will not
work if opened standalone.

Normally this is a user error though, so ask the user if this was
intended, before actually importing the build.

Task-number: QTBUG-88776
Change-Id: Ifdd5e1d1cb8a1ef9955d22493eba3a1a55dc689f
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp

@@ -129,6 +129,8 @@ CMakeBuildConfiguration::CMakeBuildConfiguration(Target *target, Utils::Id id)
     auto initialCMakeArgumentsAspect = addAspect<InitialCMakeArgumentsAspect>();
     initialCMakeArgumentsAspect->setMacroExpanderProvider([this]{ return macroExpander(); });
 
+    addAspect<SourceDirectoryAspect>();
+
     appendInitialBuildStep(Constants::CMAKE_BUILD_STEP_ID);
     appendInitialCleanStep(Constants::CMAKE_BUILD_STEP_ID);
 
@@ -190,6 +192,11 @@ CMakeBuildConfiguration::CMakeBuildConfiguration(Target *target, Utils::Id id)
                                                    info.buildType));
         }
 
+        if (info.extraInfo.isValid()) {
+            setSourceDirectory(FilePath::fromVariant(
+                        info.extraInfo.value<QVariantMap>().value(Constants::CMAKE_HOME_DIR)));
+        }
+
         setInitialCMakeArguments(initialArgs);
     });
 
@@ -486,6 +493,16 @@ void CMakeBuildConfiguration::runCMakeWithExtraArguments()
     m_buildSystem->runCMakeWithExtraArguments();
 }
 
+void CMakeBuildConfiguration::setSourceDirectory(const FilePath &path)
+{
+    aspect<SourceDirectoryAspect>()->setValue(path.toString());
+}
+
+Utils::FilePath CMakeBuildConfiguration::sourceDirectory() const
+{
+    return Utils::FilePath::fromString(aspect<SourceDirectoryAspect>()->value());
+}
+
 // ----------------------------------------------------------------------
 // - InitialCMakeParametersAspect:
 // ----------------------------------------------------------------------
@@ -497,5 +514,14 @@ InitialCMakeArgumentsAspect::InitialCMakeArgumentsAspect()
     setDisplayStyle(TextEditDisplay);
 }
 
+// -----------------------------------------------------------------------------
+// SourceDirectoryAspect:
+// -----------------------------------------------------------------------------
+SourceDirectoryAspect::SourceDirectoryAspect()
+{
+    // Will not be displayed, only persisted
+    setSettingsKey("CMake.Source.Directory");
+}
+
 } // namespace Internal
 } // namespace CMakeProjectManager