CLI: Check generator name before building

We can and should detect invalid generator names before starting a
potentially expensive operation.

Task-number: QBS-1194
Change-Id: I3588df48b7f3e3d7d085a2e4b620296f5eaf02c9
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

2 files changed, 31 insertions, 20 deletions

diff --git a/src/app/qbs/commandlinefrontend.cpp b/src/app/qbs/commandlinefrontend.cpp
index c1e9415c9..2deaf33e7 100644
--- a/src/app/qbs/commandlinefrontend.cpp
+++ b/src/app/qbs/commandlinefrontend.cpp
@@ -376,8 +376,10 @@ void CommandLineFrontend::handleProjectsResolved()
     case StatusCommandType:
         qApp->exit(printStatus(m_projects.first().projectData()));
         break;
-    case BuildCommandType:
     case GenerateCommandType:
+        checkGeneratorName();
+        Q_FALLTHROUGH();
+    case BuildCommandType:
         build();
         break;
     case InstallCommandType:
@@ -499,31 +501,35 @@ void CommandLineFrontend::build()
     m_currentBuildEffort = 0;
 }
 
-void CommandLineFrontend::generate()
+void CommandLineFrontend::checkGeneratorName()
 {
     const QString generatorName = m_parser.generateOptions().generatorName();
-    auto generator = ProjectGeneratorManager::findGenerator(generatorName);
-    if (!generator) {
-        const auto generatorNames = ProjectGeneratorManager::loadedGeneratorNames();
-        if (!generatorNames.empty()) {
-            const QString generatorNamesString = generatorNames.join(QLatin1String("\n\t"));
-            if (!generatorName.isEmpty()) {
-                throw ErrorInfo(Tr::tr("No generator named '%1'. Available generators:\n\t%2")
-                                .arg(generatorName, generatorNamesString));
-            }
-
-            throw ErrorInfo(Tr::tr("No generator specified. Available generators:\n\t%1")
-                            .arg(generatorNamesString));
+    m_generator = ProjectGeneratorManager::findGenerator(generatorName);
+    if (m_generator)
+        return;
+    const auto generatorNames = ProjectGeneratorManager::loadedGeneratorNames();
+    if (!generatorNames.empty()) {
+        const QString generatorNamesString = generatorNames.join(QLatin1String("\n\t"));
+        if (!generatorName.isEmpty()) {
+            throw ErrorInfo(Tr::tr("No generator named '%1'. Available generators:\n\t%2")
+                            .arg(generatorName, generatorNamesString));
         }
 
-        throw ErrorInfo(Tr::tr("No generator specified or no generators are available."));
+        throw ErrorInfo(Tr::tr("No generator specified. Available generators:\n\t%1")
+                        .arg(generatorNamesString));
     }
 
-    generator->generate(m_projects,
-                        m_parser.buildConfigurations(),
-                        m_parser.installOptions(QString()),
-                        m_parser.settingsDir(),
-                        ConsoleLogger::instance(m_settings));
+    throw ErrorInfo(Tr::tr("No generator specified or no generators are available."));
+}
+
+void CommandLineFrontend::generate()
+{
+    QBS_CHECK(!!m_generator);
+    m_generator->generate(m_projects,
+                          m_parser.buildConfigurations(),
+                          m_parser.installOptions(QString()),
+                          m_parser.settingsDir(),
+                          ConsoleLogger::instance(m_settings));
 }
 
 int CommandLineFrontend::runTarget()
diff --git a/src/app/qbs/commandlinefrontend.h b/src/app/qbs/commandlinefrontend.h
index ab37f6c8a..9fc1f2c5b 100644
--- a/src/app/qbs/commandlinefrontend.h
+++ b/src/app/qbs/commandlinefrontend.h
@@ -47,6 +47,8 @@
 #include <QtCore/qlist.h>
 #include <QtCore/qobject.h>
 
+#include <memory>
+
 QT_BEGIN_NAMESPACE
 class QTimer;
 QT_END_NAMESPACE
@@ -56,6 +58,7 @@ class AbstractJob;
 class ConsoleProgressObserver;
 class ErrorInfo;
 class ProcessResult;
+class ProjectGenerator;
 class Settings;
 
 class CommandLineFrontend : public QObject
@@ -88,6 +91,7 @@ private:
     void makeClean();
     int runShell();
     void build();
+    void checkGeneratorName();
     void generate();
     int runTarget();
     void updateTimestamps();
@@ -118,6 +122,7 @@ private:
     int m_totalBuildEffort;
     int m_currentBuildEffort;
     QHash<AbstractJob *, int> m_buildEfforts;
+    std::shared_ptr<ProjectGenerator> m_generator;
 };
 
 } // namespace qbs