Fix 'performance-unnecessary-value-param' warnings

Use more pass-by-const-ref since there is no point in passing objects by
value in these cases

Also, treat this warning as error

Change-Id: I5382dcd56639f535cf240205cc5c3ac667c4ece3
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

4 files changed, 5 insertions, 5 deletions

diff --git a/src/lib/corelib/buildgraph/rulecommands.cpp b/src/lib/corelib/buildgraph/rulecommands.cpp
index c09c31c2c..88ab1ce06 100644
--- a/src/lib/corelib/buildgraph/rulecommands.cpp
+++ b/src/lib/corelib/buildgraph/rulecommands.cpp
@@ -78,7 +78,7 @@ static QString stdoutFilterFunctionProperty() { return QStringLiteral("stdoutFil
 static QString timeoutProperty() { return QStringLiteral("timeout"); }
 static QString workingDirProperty() { return QStringLiteral("workingDirectory"); }
 
-static QString invokedSourceCode(const QScriptValue codeOrFunction)
+static QString invokedSourceCode(const QScriptValue &codeOrFunction)
 {
     const QString &code = codeOrFunction.toString();
     return codeOrFunction.isFunction() ? QStringLiteral("(") + code + QStringLiteral(")()") : code;
diff --git a/src/lib/corelib/buildgraph/transformer.cpp b/src/lib/corelib/buildgraph/transformer.cpp
index 5e27c3e74..29f2bcdf0 100644
--- a/src/lib/corelib/buildgraph/transformer.cpp
+++ b/src/lib/corelib/buildgraph/transformer.cpp
@@ -194,7 +194,7 @@ void Transformer::setupInputs(QScriptValue targetScriptValue, const ArtifactSet
     targetScriptValue.setProperty(StringConstants::inputVar(), inputScriptValue);
 }
 
-void Transformer::setupInputs(QScriptValue targetScriptValue)
+void Transformer::setupInputs(const QScriptValue &targetScriptValue)
 {
     setupInputs(targetScriptValue, inputs, rule->module->name);
 }
diff --git a/src/lib/corelib/buildgraph/transformer.h b/src/lib/corelib/buildgraph/transformer.h
index 2f6a8e56d..8772ed868 100644
--- a/src/lib/corelib/buildgraph/transformer.h
+++ b/src/lib/corelib/buildgraph/transformer.h
@@ -95,7 +95,7 @@ public:
                                             const Artifact *artifact,
                                             const QString &defaultModuleName);
     ResolvedProductPtr product() const;
-    void setupInputs(QScriptValue targetScriptValue);
+    void setupInputs(const QScriptValue &targetScriptValue);
     void setupOutputs(QScriptValue targetScriptValue);
     void setupExplicitlyDependsOn(QScriptValue targetScriptValue);
     void createCommands(ScriptEngine *engine, const PrivateScriptFunction &script,
diff --git a/src/lib/corelib/buildgraph/transformerchangetracking.cpp b/src/lib/corelib/buildgraph/transformerchangetracking.cpp
index 505f0cbba..e44c31639 100644
--- a/src/lib/corelib/buildgraph/transformerchangetracking.cpp
+++ b/src/lib/corelib/buildgraph/transformerchangetracking.cpp
@@ -71,7 +71,7 @@ private:
                                   const char *context) const;
     bool isExportedModuleUpToDate(const QString &productName, const ExportedModule &module) const;
     bool areExportedModulesUpToDate(
-            const std::unordered_map<QString, ExportedModule> exportedModules) const;
+            const std::unordered_map<QString, ExportedModule> &exportedModules) const;
     const Artifact *getArtifact(const QString &filePath, const QString &productName) const;
     const ResolvedProduct *getProduct(const QString &name) const;
 
@@ -207,7 +207,7 @@ bool TrafoChangeTracker::isExportedModuleUpToDate(const QString &productName,
 }
 
 bool TrafoChangeTracker::areExportedModulesUpToDate(
-        const std::unordered_map<QString, ExportedModule> exportedModules) const
+        const std::unordered_map<QString, ExportedModule> &exportedModules) const
 {
     for (const auto &kv : exportedModules) {
         if (!isExportedModuleUpToDate(kv.first, kv.second))