From fa6490efbcc486edbb8c344bc83c1370826d9fc3 Mon Sep 17 00:00:00 2001
From: Eike Ziller <eike.ziller@qt.io>
Date: Thu, 10 Jun 2021 10:31:53 +0200
Subject: [PATCH] CMake: Avoid iterating project tree for each build target

Reduces lock-up in main thread after loading projects

Task-number: QTCREATORBUG-25783
Change-Id: Ie769074f1689698379bd6fd60f74957086cfce37
Reviewed-by: hjk <hjk@qt.io>
---
 .../cmakeprojectmanager/cmakebuildsystem.cpp  | 22 +++++++++++--------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp b/src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp
index 243fdb83f9f..3f90ec7a4c5 100644
--- a/src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp
@@ -623,18 +623,22 @@ void CMakeBuildSystem::updateProjectData()
         if (newRoot) {
             setRootProjectNode(std::move(newRoot));
 
-            const FilePath buildDir = cmakeBuildConfiguration()->buildDirectory();
-            if (p->rootProjectNode()) {
+            if (QTC_GUARD(p->rootProjectNode())) {
                 const QString nodeName = p->rootProjectNode()->displayName();
                 p->setDisplayName(nodeName);
-            }
 
-            for (const CMakeBuildTarget &bt : qAsConst(m_buildTargets)) {
-                const QString buildKey = bt.title;
-                if (ProjectNode *node = p->findNodeForBuildKey(buildKey)) {
-                    if (auto targetNode = dynamic_cast<CMakeTargetNode *>(node))
-                        targetNode->setConfig(patchedConfig);
-                }
+                // set config on target nodes
+                const QSet<QString> buildKeys = Utils::transform<QSet>(m_buildTargets,
+                                                                       &CMakeBuildTarget::title);
+                p->rootProjectNode()->forEachProjectNode(
+                    [patchedConfig, buildKeys](const ProjectNode *node) {
+                        if (buildKeys.contains(node->buildKey())) {
+                            auto targetNode = const_cast<CMakeTargetNode *>(
+                                dynamic_cast<const CMakeTargetNode *>(node));
+                            if (QTC_GUARD(targetNode))
+                                targetNode->setConfig(patchedConfig);
+                        }
+                    });
             }
         }
     }