ClangTools: Allow applying fixits

Add a new column to the view that allows to check diagnostics with
fixits. The checked fixits can then be applied with the also new "Apply
Fixits" button in the toolbar.

Some corner cases are not yet handled:
 * File is open in editor
 * File changed in the mean time

Change-Id: I3d3f353a4150699a0d082f2a4348e331a4213bcf
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/clangtools/clangtidyclazytool.cpp

@@ -50,10 +50,13 @@
 #include <projectexplorer/target.h>
 #include <projectexplorer/session.h>
 
+#include <texteditor/refactoringchanges.h>
+
 #include <utils/fancylineedit.h>
 #include <utils/utilsicons.h>
 
 #include <QAction>
+#include <QToolButton>
 
 using namespace Core;
 using namespace CppTools;
@@ -66,6 +69,43 @@ namespace Internal {
 
 static ClangTidyClazyTool *s_instance;
 
+static void applyFixits(const QVector<Diagnostic> &diagnostics)
+{
+    TextEditor::RefactoringChanges changes;
+    QMap<QString, TextEditor::RefactoringFilePtr> refactoringFiles;
+
+    // Create refactoring files and changes
+    for (const Diagnostic &diagnostic : diagnostics) {
+        const auto filePath = diagnostic.location.filePath;
+        QTC_ASSERT(!filePath.isEmpty(), continue);
+
+        // Get or create refactoring file
+        TextEditor::RefactoringFilePtr refactoringFile = refactoringFiles.value(filePath);
+        if (!refactoringFile) {
+            refactoringFile = changes.file(filePath);
+            refactoringFiles.insert(filePath, refactoringFile);
+        }
+
+        // Append changes
+        ChangeSet cs = refactoringFile->changeSet();
+
+        for (const ExplainingStep &step : diagnostic.explainingSteps) {
+            if (step.isFixIt) {
+                const Debugger::DiagnosticLocation start = step.ranges.first();
+                const Debugger::DiagnosticLocation end = step.ranges.last();
+                cs.replace(refactoringFile->position(start.line, start.column),
+                           refactoringFile->position(end.line, end.column), step.message);
+            }
+        }
+
+        refactoringFile->setChangeSet(cs);
+    }
+
+    // Apply refactoring file changes
+    for (TextEditor::RefactoringFilePtr refactoringFile  : refactoringFiles.values())
+        refactoringFile->apply();
+}
+
 ClangTidyClazyTool::ClangTidyClazyTool()
     : ClangTool("Clang-Tidy and Clazy")
 {
@@ -118,6 +158,22 @@ ClangTidyClazyTool::ClangTidyClazyTool()
             QRegExp(filter, Qt::CaseSensitive, QRegExp::WildcardUnix));
     });
 
+    // Apply fixits button
+    m_applyFixitsButton = new QToolButton;
+    m_applyFixitsButton->setText(tr("Apply Fixits"));
+    connect(m_applyFixitsButton, &QToolButton::clicked, [this]() {
+        QVector<Diagnostic> diagnosticsWithFixits;
+
+        const int count = m_diagnosticModel->rootItem()->childCount();
+        for (int i = 0; i < count; ++i) {
+            auto *item = static_cast<DiagnosticItem *>(m_diagnosticModel->rootItem()->childAt(i));
+            if (item->applyFixits())
+                diagnosticsWithFixits += item->diagnostic();
+        }
+
+        applyFixits(diagnosticsWithFixits);
+    });
+
     ActionContainer *menu = ActionManager::actionContainer(Debugger::Constants::M_DEBUG_ANALYZER);
     const QString toolTip = tr("Clang-Tidy and Clazy use a customized Clang executable from the "
                                "Clang project to search for errors and warnings.");
@@ -143,6 +199,7 @@ ClangTidyClazyTool::ClangTidyClazyTool()
     tidyClazyToolbar.addAction(m_goBack);
     tidyClazyToolbar.addAction(m_goNext);
     tidyClazyToolbar.addWidget(m_filterLineEdit);
+    tidyClazyToolbar.addWidget(m_applyFixitsButton);
     Debugger::registerToolbar(ClangTidyClazyPerspectiveId, tidyClazyToolbar);
 
     updateRunActions();