logic: only use precompiled headers for compilation database commands that specify the "-include-pch" flag (issue #719)

src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCxxPch.cpp

@@ -1,8 +1,13 @@
 #include "QtProjectWizardContentPathCxxPch.h"
 
+#include <QMessageBox>
+
+#include "IndexerCommandCxx.h"
+#include "SourceGroupSettingsCxxCdb.h"
 #include "SourceGroupSettingsWithCxxPchOptions.h"
 #include "utility.h"
 #include "utilityFile.h"
+#include "utilitySourceGroupCxx.h"
 
 QtProjectWizardContentPathCxxPch::QtProjectWizardContentPathCxxPch(
 	std::shared_ptr<SourceGroupSettings> settings,
@@ -40,6 +45,44 @@ void QtProjectWizardContentPathCxxPch::save()
 	m_settingsCxxPch->setPchInputFilePathFilePath(FilePath(m_picker->getText().toStdWString()));
 }
 
+bool QtProjectWizardContentPathCxxPch::check()
+{
+	if (std::shared_ptr<SourceGroupSettingsCxxCdb> cdbSettings = std::dynamic_pointer_cast<SourceGroupSettingsCxxCdb>(m_settings))
+	{
+		const FilePath cdbPath = cdbSettings->getCompilationDatabasePathExpandedAndAbsolute();
+		std::shared_ptr<clang::tooling::JSONCompilationDatabase> cdb = IndexerCommandCxx::loadCDB(cdbPath);
+		if (!cdb)
+		{
+			QMessageBox msgBox;
+			msgBox.setText("Unable to open and read the provided compilation database file.");
+			msgBox.exec();
+			return false;
+		}
+
+		if (utility::containsIncludePchFlags(cdb))
+		{
+			if (m_settingsCxxPch->getPchInputFilePath().empty())
+			{
+				QMessageBox msgBox;
+				msgBox.setText("The provided compilation database file uses precompiled headers. Please specify a Precompiled Header input file.");
+				msgBox.exec();
+				return false;
+			}
+		}
+		else
+		{
+			if (!m_settingsCxxPch->getPchInputFilePath().empty())
+			{
+				QMessageBox msgBox;
+				msgBox.setText("The provided compilation database file does not use precompiled headers. Please do not specify a Precompiled Header input file.");
+				msgBox.exec();
+				return false;
+			}
+		}
+	}
+	return true;
+}
+
 std::shared_ptr<SourceGroupSettings> QtProjectWizardContentPathCxxPch::getSourceGroupSettings()
 {
 	return m_settings;

src/lib_gui/qt/project_wizard/content/path/QtProjectWizardContentPathCxxPch.h

@@ -22,6 +22,7 @@ public:
 
 	void load() override;
 	void save() override;
+	bool check() override;
 
 private:
 	std::shared_ptr<SourceGroupSettings> getSourceGroupSettings() override;