From a1b78d42348bef01090ff9b39c7eeb713f432f47 Mon Sep 17 00:00:00 2001
From: Christian Kandeler <christian.kandeler@qt.io>
Date: Fri, 3 Nov 2023 09:46:50 +0100
Subject: [PATCH] ClangCodeModel: Fix shadow document handling

Our approach was not fully thought through: When we got informed of a
file getting created by an ExtraCompiler, we would make it known to the
first client that came along and then forget about it. This means that
e.g. a source file including a UI header would parse fine with the first
client that opened it, but after switching the build configuration or
possibly even just touching the project file, the UI header would not be
found anymore.
Fix this by keeping the information about generated files around and
attaching them to every newly initialized client.
Note that this state should probably be kept somewhere more central.

Change-Id: Ib1d8cca9258d1962513d8d463f5d16f9ff91a048
Reviewed-by: David Schulz <david.schulz@qt.io>
---
 .../clangmodelmanagersupport.cpp              | 28 ++++++++-----------
 .../clangcodemodel/clangmodelmanagersupport.h |  2 +-
 src/plugins/languageclient/client.cpp         |  2 ++
 3 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
index e117e6b36f1..a25ceef0ff5 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
@@ -553,17 +553,15 @@ void ClangModelManagerSupport::updateLanguageClient(Project *project)
                 hasDocuments = true;
             }
 
-            for (auto it = m_queuedShadowDocuments.begin(); it != m_queuedShadowDocuments.end();) {
-                if (fileIsProjectBuildArtifact(client, it.key())) {
-                    if (it.value().isEmpty())
-                        client->removeShadowDocument(it.key());
-                    else
-                        client->setShadowDocument(it.key(), it.value());
-                    ClangdClient::handleUiHeaderChange(it.key().fileName());
-                    it = m_queuedShadowDocuments.erase(it);
-                } else {
-                    ++it;
-                }
+            for (auto it = m_potentialShadowDocuments.begin();
+                 it != m_potentialShadowDocuments.end(); ++it) {
+                if (!fileIsProjectBuildArtifact(client, it.key()))
+                    continue;
+                if (it.value().isEmpty())
+                    client->removeShadowDocument(it.key());
+                else
+                    client->setShadowDocument(it.key(), it.value());
+                ClangdClient::handleUiHeaderChange(it.key().fileName());
             }
 
             updateParserConfig(client);
@@ -799,10 +797,8 @@ void ClangModelManagerSupport::onAbstractEditorSupportContentsUpdated(const QStr
     if (Client * const client = clientForGeneratedFile(fp)) {
         client->setShadowDocument(fp, stringContent);
         ClangdClient::handleUiHeaderChange(fp.fileName());
-        QTC_CHECK(m_queuedShadowDocuments.remove(fp) == 0);
-    } else  {
-        m_queuedShadowDocuments.insert(fp, stringContent);
     }
+    m_potentialShadowDocuments.insert(fp, stringContent);
 }
 
 void ClangModelManagerSupport::onAbstractEditorSupportRemoved(const QString &filePath)
@@ -813,10 +809,8 @@ void ClangModelManagerSupport::onAbstractEditorSupportRemoved(const QString &fil
     if (Client * const client = clientForGeneratedFile(fp)) {
         client->removeShadowDocument(fp);
         ClangdClient::handleUiHeaderChange(fp.fileName());
-        QTC_CHECK(m_queuedShadowDocuments.remove(fp) == 0);
-    } else {
-        m_queuedShadowDocuments.insert(fp, {});
     }
+    m_potentialShadowDocuments.remove(fp);
 }
 
 void addFixItsActionsToMenu(QMenu *menu, const TextEditor::QuickFixOperations &fixItOperations)
diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.h b/src/plugins/clangcodemodel/clangmodelmanagersupport.h
index 8121b9967a9..cc361127836 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.h
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.h
@@ -96,7 +96,7 @@ private:
     Utils::FutureSynchronizer m_generatorSynchronizer;
     QList<QPointer<ClangdClient>> m_clientsToRestart;
     QTimer * const m_clientRestartTimer;
-    QHash<Utils::FilePath, QString> m_queuedShadowDocuments;
+    QHash<Utils::FilePath, QString> m_potentialShadowDocuments;
 };
 
 } // namespace Internal
diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index 7583b065988..976704fed5b 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -1058,6 +1058,8 @@ void Client::setShadowDocument(const Utils::FilePath &filePath, const QString &c
     if (shadowIt == d->m_shadowDocuments.end()) {
         shadowIt = d->m_shadowDocuments.insert(filePath, {content, {}});
     } else  {
+        if (shadowIt.value().first == content)
+            return;
         shadowIt.value().first = content;
         if (!shadowIt.value().second.isEmpty()) {
             VersionedTextDocumentIdentifier docId(hostPathToServerUri(filePath));