ClangTools: Show hint when disabling "Build the project before analysis."

Show also the same hint as a tooltip.

Fixes: QTCREATORBUG-22382
Change-Id: If1b594994cea387d6727775ce4c28c21d51f2d86
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangtools/clangselectablefilesdialog.cpp

@@ -295,6 +295,7 @@ SelectableFilesDialog::SelectableFilesDialog(const ProjectInfo &projectInfo,
     CppTools::ClangDiagnosticConfigsSelectionWidget *diagnosticConfigsSelectionWidget
             = m_ui->clangToolsBasicSettings->ui()->clangDiagnosticConfigsSelectionWidget;
     QCheckBox *buildBeforeAnalysis = m_ui->clangToolsBasicSettings->ui()->buildBeforeAnalysis;
+    buildBeforeAnalysis->setToolTip(hintAboutBuildBeforeAnalysis());
 
     ClangToolsProjectSettings *settings = ClangToolsProjectSettingsManager::getSettings(m_project);
     m_customDiagnosticConfig = diagnosticConfiguration(settings);
@@ -337,6 +338,8 @@ SelectableFilesDialog::SelectableFilesDialog(const ProjectInfo &projectInfo,
             m_customDiagnosticConfig = currentConfigId;
     });
     connect(buildBeforeAnalysis, &QCheckBox::toggled, [this](bool checked) {
+        if (!checked)
+            showHintAboutBuildBeforeAnalysis();
         if (m_ui->globalOrCustom->currentIndex() == CustomSettings)
             m_buildBeforeAnalysis = checked;
     });

src/plugins/clangtools/clangtoolsconfigwidget.cpp

@@ -56,9 +56,12 @@ ClangToolsConfigWidget::ClangToolsConfigWidget(
             [settings](int count) { settings->setSimultaneousProcesses(count); });
 
     QCheckBox *buildBeforeAnalysis = m_ui->clangToolsBasicSettings->ui()->buildBeforeAnalysis;
+    buildBeforeAnalysis->setToolTip(hintAboutBuildBeforeAnalysis());
     buildBeforeAnalysis->setCheckState(settings->savedBuildBeforeAnalysis()
                                               ? Qt::Checked : Qt::Unchecked);
     connect(buildBeforeAnalysis, &QCheckBox::toggled, [settings](bool checked) {
+        if (!checked)
+            showHintAboutBuildBeforeAnalysis();
         settings->setBuildBeforeAnalysis(checked);
     });
 

src/plugins/clangtools/clangtoolsutils.cpp

@@ -25,6 +25,7 @@
 
 #include "clangtoolsutils.h"
 
+#include "clangtool.h"
 #include "clangtoolsdiagnostic.h"
 #include "clangtoolssettings.h"
 
@@ -32,8 +33,9 @@
 
 #include <projectexplorer/projectexplorerconstants.h>
 
-#include <utils/hostosinfo.h>
+#include <utils/checkablemessagebox.h>
 #include <utils/environment.h>
+#include <utils/hostosinfo.h>
 #include <utils/synchronousprocess.h>
 
 #include <QCoreApplication>
@@ -49,5 +51,24 @@ QString createFullLocationString(const Debugger::DiagnosticLocation &location)
             + QLatin1Char(':') + QString::number(location.column);
 }
 
+QString hintAboutBuildBeforeAnalysis()
+{
+    return ClangTool::tr(
+        "In general, the project should be built before starting the analysis to ensure that the "
+        "code to analyze is valid.<br/><br/>"
+        "Building the project might also run code generators that update the source files as "
+        "necessary.");
+}
+
+void showHintAboutBuildBeforeAnalysis()
+{
+    Utils::CheckableMessageBox::doNotShowAgainInformation(
+        Core::ICore::dialogParent(),
+        ClangTool::tr("Info About Build the Project Before Analysis"),
+        hintAboutBuildBeforeAnalysis(),
+        Core::ICore::settings(),
+        "ClangToolsDisablingBuildBeforeAnalysisHint");
+}
+
 } // namespace Internal
 } // namespace ClangTools

src/plugins/clangtools/clangtoolsutils.h

@@ -41,5 +41,8 @@ namespace Internal {
 
 QString createFullLocationString(const Debugger::DiagnosticLocation &location);
 
+QString hintAboutBuildBeforeAnalysis();
+void showHintAboutBuildBeforeAnalysis();
+
 } // namespace Internal
 } // namespace ClangTools