ClangCodeModel: Add experimental clangd support

If the user has enabled clangd (default is off), we start up one instance
per project when it is opened/changed (including build config switches),
and trigger background indexing.
So far, the index is used to provide results for locators and "Find
Usages".
Per-document functionality such as semantic highlighting and completion
is still provided by libclang.

Change-Id: I12532fca1b9c6278baab560e7238cba6189cde9f
Reviewed-by: David Schulz <david.schulz@qt.io>

1 files changed, 23 insertions, 0 deletions

diff --git a/src/plugins/cpptools/cppcodemodelsettingspage.cpp b/src/plugins/cpptools/cppcodemodelsettingspage.cpp
index 2c1b0ddc02..00e7b8081a 100644
--- a/src/plugins/cpptools/cppcodemodelsettingspage.cpp
+++ b/src/plugins/cpptools/cppcodemodelsettingspage.cpp
@@ -100,6 +100,9 @@ void CppCodeModelSettingsWidget::setupClangCodeModelWidgets()
     const bool isClangActive = CppModelManager::instance()->isClangCodeModelActive();
     m_ui->clangCodeModelIsDisabledHint->setVisible(!isClangActive);
     m_ui->clangCodeModelIsEnabledHint->setVisible(isClangActive);
+    m_ui->clangdCheckBox->setVisible(isClangActive);
+    m_ui->clangdChooser->setVisible(isClangActive);
+
     for (int i = 0; i < m_ui->clangDiagnosticConfigsSelectionWidget->layout()->count(); ++i) {
         QWidget *widget = m_ui->clangDiagnosticConfigsSelectionWidget->layout()->itemAt(i)->widget();
         if (widget)
@@ -117,6 +120,16 @@ void CppCodeModelSettingsWidget::setupGeneralWidgets()
 
     const bool ignorePch = m_settings->pchUsage() == CppCodeModelSettings::PchUse_None;
     m_ui->ignorePCHCheckBox->setChecked(ignorePch);
+
+    m_ui->clangdCheckBox->setChecked(m_settings->useClangd());
+    m_ui->clangdCheckBox->setToolTip(tr("Use clangd for locators and \"Find References\".\n"
+        "Changing this option does not affect projects that are already open."));
+    m_ui->clangdChooser->setExpectedKind(Utils::PathChooser::ExistingCommand);
+    m_ui->clangdChooser->setFilePath(codeModelSettings()->clangdFilePath());
+    m_ui->clangdChooser->setEnabled(m_ui->clangdCheckBox->isChecked());
+    connect(m_ui->clangdCheckBox, &QCheckBox::toggled, m_ui->clangdChooser, [this](bool checked) {
+        m_ui->clangdChooser->setEnabled(checked);
+    });
 }
 
 bool CppCodeModelSettingsWidget::applyClangCodeModelWidgetsToSettings() const
@@ -163,6 +176,16 @@ bool CppCodeModelSettingsWidget::applyGeneralWidgetsToSettings() const
         m_settings->setIndexerFileSizeLimitInMb(newFileSizeLimit);
         settingsChanged = true;
     }
+    const bool newUseClangd = m_ui->clangdCheckBox->isChecked();
+    if (m_settings->useClangd() != newUseClangd) {
+        m_settings->setUseClangd(newUseClangd);
+        settingsChanged = true;
+    }
+    const Utils::FilePath newClangdPath = m_ui->clangdChooser->rawFilePath();
+    if (m_settings->clangdFilePath() != newClangdPath) {
+        m_settings->setClangdFilePath(newClangdPath);
+        settingsChanged = true;
+    }
 
     const bool newIgnorePch = m_ui->ignorePCHCheckBox->isChecked();
     const bool previousIgnorePch = m_settings->pchUsage() == CppCodeModelSettings::PchUse_None;