CppEditor: Try harder to prevent code folding in ifdefed-out code

The syntax highlighter can re-run after the semantic highlighter,
overwriting its changes.
Amends 2bfa16daa1.

Change-Id: I1c4efa5033ef4152e2d77dc2d99edbceac4e13c1
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cppeditor/cppeditordocument.cpp

@@ -79,6 +79,8 @@ CppEditorDocument::CppEditorDocument()
 {
     setId(CppEditor::Constants::CPPEDITOR_ID);
     resetSyntaxHighlighter([] { return new CppHighlighter(); });
+    connect(syntaxHighlighter(), &SyntaxHighlighter::finished,
+            this, &CppEditorDocument::applyIfdefedOutBlocks);
 
     ICodeStylePreferencesFactory *factory
         = TextEditorSettings::codeStyleFactory(Constants::CPP_SETTINGS_ID);
@@ -310,15 +312,15 @@ void CppEditorDocument::setExtraPreprocessorDirectives(const QByteArray &directi
 
 void CppEditorDocument::setIfdefedOutBlocks(const QList<TextEditor::BlockRange> &blocks)
 {
-    if (syntaxHighlighter() && !syntaxHighlighter()->syntaxHighlighterUpToDate()) {
+    m_ifdefedOutBlocks = blocks;
-        connect(syntaxHighlighter(),
+    applyIfdefedOutBlocks();
-            &SyntaxHighlighter::finished,
-            this,
-            [this, blocks] { setIfdefedOutBlocks(blocks); },
-            Qt::SingleShotConnection);
-        return;
 }
 
+void CppEditorDocument::applyIfdefedOutBlocks()
+{
+    if (!syntaxHighlighter() || !syntaxHighlighter()->syntaxHighlighterUpToDate())
+        return;
+
     auto documentLayout = qobject_cast<TextDocumentLayout*>(document()->documentLayout());
     QTC_ASSERT(documentLayout, return);
 
@@ -328,8 +330,8 @@ void CppEditorDocument::setIfdefedOutBlocks(const QList<TextEditor::BlockRange>
     int previousBraceDepth = 0;
     while (block.isValid()) {
         bool resetToPrevious = false;
-        if (rangeNumber < blocks.size()) {
+        if (rangeNumber < m_ifdefedOutBlocks.size()) {
-            const BlockRange &range = blocks.at(rangeNumber);
+            const BlockRange &range = m_ifdefedOutBlocks.at(rangeNumber);
             if (block.position() >= range.first()
                 && ((block.position() + block.length() - 1) <= range.last() || !range.last())) {
                 TextDocumentLayout::setIfdefedOut(block);
@@ -366,6 +368,10 @@ void CppEditorDocument::setIfdefedOutBlocks(const QList<TextEditor::BlockRange>
 
     if (needUpdate)
         documentLayout->requestUpdate();
+
+#ifdef WITH_TESTS
+    emit ifdefedOutBlocksApplied();
+#endif
 }
 
 void CppEditorDocument::setPreferredParseContext(const QString &parseContextId)

src/plugins/cppeditor/cppeditordocument.h

@@ -52,6 +52,10 @@ public:
 
     bool usesClangd() const;
 
+#ifdef WITH_TESTS
+    QList<TextEditor::BlockRange> ifdefedOutBlocks() const { return m_ifdefedOutBlocks; }
+#endif
+
 signals:
     void codeWarningsUpdated(unsigned contentsRevision,
                              const QList<QTextEdit::ExtraSelection> selections,
@@ -65,6 +69,10 @@ signals:
 
     void preprocessorSettingsChanged(bool customSettings);
 
+#ifdef WITH_TESTS
+    void ifdefedOutBlocksApplied();
+#endif
+
 protected:
     void applyFontSettings() override;
     Utils::Result saveImpl(const Utils::FilePath &filePath, bool autoSave) override;
@@ -93,6 +101,7 @@ private:
     void releaseResources();
 
     void showHideInfoBarAboutMultipleParseContexts(bool show);
+    void applyIfdefedOutBlocks();
 
     void initializeTimer();
 
@@ -116,6 +125,7 @@ private:
 
     ParseContextModel m_parseContextModel;
     OutlineModel m_overviewModel;
+    QList<TextEditor::BlockRange> m_ifdefedOutBlocks;
 };
 
 } // namespace Internal

src/plugins/cppeditor/cpphighlighter.cpp

@@ -4,6 +4,7 @@
 #include "cpphighlighter.h"
 
 #include "cppdoxygen.h"
+#include "cppeditordocument.h"
 #include "cppeditorlogging.h"
 #include "cpptoolsreuse.h"
 
@@ -13,7 +14,6 @@
 #include <utils/textutils.h>
 
 #include <cplusplus/SimpleLexer.h>
-#include <cplusplus/Lexer.h>
 
 #include <QFile>
 #include <QTextCharFormat>
@@ -904,10 +904,16 @@ int main() {                              // 1,0
                 QCOMPARE(actual, expected);
             }
         };
-        connect(testDocument.m_editorWidget, &CppEditorWidget::ifdefedOutBlocksChanged,
+
+        if (testDocument.m_editorWidget->cppEditorDocument()->ifdefedOutBlocks().isEmpty()) {
+            connect(testDocument.m_editorWidget->cppEditorDocument(),
+                    &CppEditorDocument::ifdefedOutBlocksApplied,
                     this, check);
             t.start(5000);
             QCOMPARE(loop.exec(), 0);
+        } else {
+            check();
+        }
     }
 
     void cleanup()