ClangCodeModel: Allow more than one in-flight "follow symbol"

The original code was written with only the interactive case in mind, but
nowadays we also start "follow symbol" operations internally as part of
e.g. quickfixes.

Change-Id: I95928297fab16f9b0469bfd66ad687447b902fd9
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdclient.cpp

@@ -349,7 +349,7 @@ public:
 
     ClangdClient * const q;
     const CppEditor::ClangdSettings::Data settings;
-    ClangdFollowSymbol *followSymbol = nullptr;
+    QList<ClangdFollowSymbol *> followSymbolOps;
     ClangdSwitchDeclDef *switchDeclDef = nullptr;
     ClangdFindLocalReferences *findLocalRefs = nullptr;
     std::optional<QVersionNumber> versionNumber;
@@ -501,8 +501,8 @@ ClangdClient::ClangdClient(Project *project, const Utils::FilePath &jsonDbDir, c
 
 ClangdClient::~ClangdClient()
 {
-    if (d->followSymbol)
-        d->followSymbol->clear();
+    for (ClangdFollowSymbol * const followSymbol : std::as_const(d->followSymbolOps))
+        followSymbol->clear();
     delete d;
 }
 
@@ -990,7 +990,7 @@ MessageId ClangdClient::requestSymbolInfo(const Utils::FilePath &filePath, const
 #ifdef WITH_TESTS
 ClangdFollowSymbol *ClangdClient::currentFollowSymbolOperation()
 {
-    return d->followSymbol;
+    return d->followSymbolOps.isEmpty() ? nullptr : d->followSymbolOps.first();
 }
 #endif
 
@@ -1005,8 +1005,20 @@ void ClangdClient::followSymbol(TextDocument *document,
 {
     QTC_ASSERT(documentOpen(document), openDocument(document));
 
-    if (d->followSymbol)
-        d->followSymbol->cancel();
+    const ClangdFollowSymbol::Origin origin
+        = CppEditor::CppCodeModelSettings::isInteractiveFollowSymbol()
+              ? ClangdFollowSymbol::Origin::User
+              : ClangdFollowSymbol::Origin::Code;
+    if (origin == ClangdFollowSymbol::Origin::User) {
+        for (auto it = d->followSymbolOps.begin(); it != d->followSymbolOps.end(); ) {
+            if ((*it)->isInteractive()) {
+                (*it)->cancel();
+                it = d->followSymbolOps.erase(it);
+            } else {
+                ++it;
+            }
+        }
+    }
 
     const QTextCursor adjustedCursor = d->adjustedCursor(cursor, document);
     if (followTo == FollowTo::SymbolDef && !resolveTarget) {
@@ -1020,14 +1032,13 @@ void ClangdClient::followSymbol(TextDocument *document,
 
     qCDebug(clangdLog) << "follow symbol requested" << document->filePath()
                        << adjustedCursor.blockNumber() << adjustedCursor.positionInBlock();
-    auto clangdFollowSymbol = new ClangdFollowSymbol(this, adjustedCursor, editorWidget, document,
-                                                     callback, followTo, openInSplit);
+    auto clangdFollowSymbol = new ClangdFollowSymbol(this, origin, adjustedCursor, editorWidget,
+                                                     document, callback, followTo, openInSplit);
     connect(clangdFollowSymbol, &ClangdFollowSymbol::done, this, [this, clangdFollowSymbol] {
         clangdFollowSymbol->deleteLater();
-        if (clangdFollowSymbol == d->followSymbol)
-            d->followSymbol = nullptr;
+        d->followSymbolOps.removeOne(clangdFollowSymbol);
     });
-    d->followSymbol = clangdFollowSymbol;
+    d->followSymbolOps << clangdFollowSymbol;
 }
 
 void ClangdClient::switchDeclDef(TextDocument *document, const QTextCursor &cursor,

src/plugins/clangcodemodel/clangdfollowsymbol.cpp

@@ -73,10 +73,10 @@ private:
 class ClangdFollowSymbol::Private
 {
 public:
-    Private(ClangdFollowSymbol *q, ClangdClient *client, const QTextCursor &cursor,
+    Private(ClangdFollowSymbol *q, ClangdClient *client, Origin origin, const QTextCursor &cursor,
             CppEditorWidget *editorWidget, const FilePath &filePath, const LinkHandler &callback,
             bool openInSplit)
-        : q(q), client(client), cursor(cursor), editorWidget(editorWidget),
+        : q(q), client(client), origin(origin), cursor(cursor), editorWidget(editorWidget),
           uri(client->hostPathToServerUri(filePath)), callback(callback),
           virtualFuncAssistProvider(q),
           docRevision(editorWidget ? editorWidget->textDocument()->document()->revision() : -1),
@@ -94,6 +94,7 @@ public:
 
     ClangdFollowSymbol * const q;
     ClangdClient * const client;
+    const Origin origin;
     const QTextCursor cursor;
     const QPointer<CppEditor::CppEditorWidget> editorWidget;
     const DocumentUri uri;
@@ -117,11 +118,11 @@ public:
     bool done = false;
 };
 
-ClangdFollowSymbol::ClangdFollowSymbol(ClangdClient *client, const QTextCursor &cursor,
-        CppEditorWidget *editorWidget, TextDocument *document, const LinkHandler &callback,
-        FollowTo followTo, bool openInSplit)
+ClangdFollowSymbol::ClangdFollowSymbol(ClangdClient *client, Origin origin,
+        const QTextCursor &cursor, CppEditorWidget *editorWidget, TextDocument *document,
+        const LinkHandler &callback, FollowTo followTo, bool openInSplit)
     : QObject(client),
-      d(new Private(this, client, cursor, editorWidget, document->filePath(), callback,
+      d(new Private(this, client, origin, cursor, editorWidget, document->filePath(), callback,
                     openInSplit))
 {
     // Abort if the user does something else with the document in the meantime.
@@ -193,6 +194,11 @@ void ClangdFollowSymbol::clear()
     d->pendingGotoDefRequests.clear();
 }
 
+bool ClangdFollowSymbol::isInteractive() const
+{
+    return d->origin == Origin::User;
+}
+
 void ClangdFollowSymbol::emitDone(const Link &link)
 {
     if (d->done)

src/plugins/clangcodemodel/clangdfollowsymbol.h

@@ -23,7 +23,9 @@ class ClangdFollowSymbol : public QObject
 {
     Q_OBJECT
 public:
-    ClangdFollowSymbol(ClangdClient *client, const QTextCursor &cursor,
+    enum class Origin { User, Code };
+
+    ClangdFollowSymbol(ClangdClient *client, Origin origin, const QTextCursor &cursor,
                        CppEditor::CppEditorWidget *editorWidget,
                        TextEditor::TextDocument *document, const Utils::LinkHandler &callback,
                        FollowTo followTo, bool openInSplit);
@@ -31,6 +33,8 @@ public:
     void cancel();
     void clear();
 
+    bool isInteractive() const;
+
 signals:
     void done();