CMake: Trigger cmake run *before* build when files changed

Make sure to run cmake *before* cmake --build when cmake files just
got saved. This helps e.g. when editing CMakeLists.txt files and the
hitting "Built" and "Save all" (or "Always save before build").

Task-number: QTCREATORBUG-16187
Change-Id: I16b1d02eb342a447003380946ce7a9d785476a0e
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/cmakeprojectmanager/builddirmanager.cpp

@@ -34,6 +34,7 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/documentmanager.h>
 #include <coreplugin/messagemanager.h>
+#include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/progressmanager/progressmanager.h>
 #include <projectexplorer/kit.h>
 #include <projectexplorer/project.h>
@@ -106,8 +107,10 @@ BuildDirManager::BuildDirManager(CMakeBuildConfiguration *bc) :
     m_projectName = sourceDirectory().fileName();
 
     m_reparseTimer.setSingleShot(true);
-    m_reparseTimer.setInterval(2000);
+
     connect(&m_reparseTimer, &QTimer::timeout, this, &BuildDirManager::parse);
+    connect(Core::EditorManager::instance(), &Core::EditorManager::aboutToSave,
+            this, &BuildDirManager::handleDocumentSaves);
 }
 
 BuildDirManager::~BuildDirManager()
@@ -164,7 +167,7 @@ void BuildDirManager::cmakeFilesChanged()
     if (!tool->isAutoRun())
         return;
 
-    m_reparseTimer.start();
+    m_reparseTimer.start(1000);
 }
 
 void BuildDirManager::forceReparse()
@@ -191,6 +194,11 @@ void BuildDirManager::resetData()
     m_files.clear();
 }
 
+bool BuildDirManager::updateCMakeStateBeforeBuild()
+{
+    return m_reparseTimer.isActive();
+}
+
 bool BuildDirManager::persistCMakeState()
 {
     if (!m_tempDir)
@@ -592,6 +600,14 @@ void BuildDirManager::checkConfiguration()
     }
 }
 
+void BuildDirManager::handleDocumentSaves(Core::IDocument *document)
+{
+    if (!m_cmakeFiles.contains(document->filePath()))
+        return;
+
+    m_reparseTimer.start(100);
+}
+
 static QByteArray trimCMakeCacheLine(const QByteArray &in) {
     int start = 0;
     while (start < in.count() && (in.at(start) == ' ' || in.at(start) == '\t'))

src/plugins/cmakeprojectmanager/builddirmanager.h

@@ -44,6 +44,8 @@
 QT_FORWARD_DECLARE_CLASS(QTemporaryDir);
 QT_FORWARD_DECLARE_CLASS(QFileSystemWatcher);
 
+namespace Core { class IDocument; }
+
 namespace ProjectExplorer {
 class FileNode;
 class IOutputParser;
@@ -74,6 +76,7 @@ public:
     void forceReparse();
     void maybeForceReparse(); // Only reparse if the configuration has changed...
     void resetData();
+    bool updateCMakeStateBeforeBuild();
     bool persistCMakeState();
 
     void generateProjectTree(CMakeProjectNode *root);
@@ -83,6 +86,7 @@ public:
 
     void checkConfiguration();
 
+    void handleDocumentSaves(Core::IDocument *document);
     void handleCmakeFileChange();
 
 signals:

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp

@@ -61,7 +61,8 @@ const char INITIAL_ARGUMENTS[] = "CMakeProjectManager.CMakeBuildConfiguration.In
 const char CONFIGURATION_KEY[] = "CMake.Configuration";
 
 CMakeBuildConfiguration::CMakeBuildConfiguration(ProjectExplorer::Target *parent) :
-    BuildConfiguration(parent, Core::Id(Constants::CMAKE_BC_ID))
+    BuildConfiguration(parent, Core::Id(Constants::CMAKE_BC_ID)),
+    m_buildDirManager(new BuildDirManager(this))
 {
     ctor();
 }
@@ -84,7 +85,8 @@ QString CMakeBuildConfiguration::disabledReason() const
 CMakeBuildConfiguration::CMakeBuildConfiguration(ProjectExplorer::Target *parent,
                                                  CMakeBuildConfiguration *source) :
     BuildConfiguration(parent, source),
-    m_configuration(source->m_configuration)
+    m_configuration(source->m_configuration),
+    m_buildDirManager(new BuildDirManager(this))
 {
     ctor();
     cloneSteps(source);
@@ -137,7 +139,6 @@ void CMakeBuildConfiguration::ctor()
                                            target()->kit(),
                                            displayName(), BuildConfiguration::Unknown));
 
-    m_buildDirManager = new BuildDirManager(this);
     connect(m_buildDirManager, &BuildDirManager::dataAvailable,
             this, &CMakeBuildConfiguration::dataAvailable);
     connect(m_buildDirManager, &BuildDirManager::errorOccured,
@@ -174,6 +175,11 @@ bool CMakeBuildConfiguration::persistCMakeState()
     return m_buildDirManager->persistCMakeState();
 }
 
+bool CMakeBuildConfiguration::updateCMakeStateBeforeBuild()
+{
+    return m_buildDirManager->updateCMakeStateBeforeBuild();
+}
+
 void CMakeBuildConfiguration::runCMake()
 {
     if (!m_buildDirManager || m_buildDirManager->isParsing())

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.h

@@ -76,6 +76,7 @@ public:
     void maybeForceReparse();
     void resetData();
     bool persistCMakeState();
+    bool updateCMakeStateBeforeBuild();
     void runCMake();
     void clearCache();
 
@@ -111,7 +112,7 @@ private:
 
     mutable QList<CMakeConfigItem> m_completeConfigurationCache;
 
-    BuildDirManager *m_buildDirManager = nullptr;
+    BuildDirManager *const m_buildDirManager = nullptr;
 
     friend class CMakeBuildSettingsWidget;
     friend class CMakeProjectManager::CMakeProject;

src/plugins/cmakeprojectmanager/cmakebuildstep.cpp

@@ -235,9 +235,18 @@ void CMakeBuildStep::run(QFutureInterface<bool> &fi)
         bc = qobject_cast<CMakeBuildConfiguration *>(target()->activeBuildConfiguration());
     QTC_ASSERT(bc, return);
 
+    bool mustDelay = false;
     if (bc->persistCMakeState()) {
         emit addOutput(tr("Persisting CMake state..."), BuildStep::MessageOutput);
+        mustDelay = true;
+    } else if (bc->updateCMakeStateBeforeBuild()) {
+        emit addOutput(tr("Running CMake in preparation to build..."), BuildStep::MessageOutput);
+        mustDelay = true;
+    } else {
+        mustDelay = false;
+    }
 
+    if (mustDelay) {
         m_runTrigger = connect(bc, &CMakeBuildConfiguration::dataAvailable,
                                this, [this, &fi]() { runImpl(fi); });
         m_errorTrigger = connect(bc, &CMakeBuildConfiguration::errorOccured,