ProjectData: return const values/references

Qbs does not care that much about binary compatilibity (because of qbs
session) and thus is is preferable to return members by const-ref
(saving 2 atomic operations and preventing from accidental detaches). In
case when method needs to compute some value instead of returning member
directly, the function signature can be changed.

Change-Id: I4e8d228761a990d274e77652c94adf9f43a758f1
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

7 files changed, 25 insertions, 33 deletions

diff --git a/src/app/qbs/commandlinefrontend.cpp b/src/app/qbs/commandlinefrontend.cpp
index d8b4d9ca8..4a28b93ec 100644
--- a/src/app/qbs/commandlinefrontend.cpp
+++ b/src/app/qbs/commandlinefrontend.cpp
@@ -351,8 +351,7 @@ CommandLineFrontend::ProductMap CommandLineFrontend::productsToUse() const
     for (const Project &project : qAsConst(m_projects)) {
         QList<ProductData> &productList = products[project];
         const ProjectData projectData = project.projectData();
-        const auto products = projectData.allProducts();
-        for (const ProductData &product : products) {
+        for (const ProductData &product : projectData.allProducts()) {
             productNames << product.name();
             if (useAll || m_parser.products().contains(product.name())) {
                 productList.push_back(product);
@@ -647,8 +646,7 @@ ProductData CommandLineFrontend::getTheOneRunnableProduct()
     QBS_CHECK(m_projects.size() == 1); // Has been checked earlier.
 
     if (m_parser.products().size() == 1) {
-        const auto products = m_projects.front().projectData().allProducts();
-        for (const ProductData &p : products) {
+        for (const ProductData &p : m_projects.front().projectData().allProducts()) {
             if (p.name() == m_parser.products().constFirst())
                 return p;
         }
@@ -657,8 +655,7 @@ ProductData CommandLineFrontend::getTheOneRunnableProduct()
     QBS_CHECK(m_parser.products().isEmpty());
 
     QList<ProductData> runnableProducts;
-    const auto products = m_projects.front().projectData().allProducts();
-    for (const ProductData &p : products) {
+    for (const ProductData &p : m_projects.front().projectData().allProducts()) {
         if (p.isRunnable())
             runnableProducts.push_back(p);
     }
diff --git a/src/app/qbs/status.cpp b/src/app/qbs/status.cpp
index 3dc540ff5..2efc6e36a 100644
--- a/src/app/qbs/status.cpp
+++ b/src/app/qbs/status.cpp
@@ -134,8 +134,7 @@ int printStatus(const ProjectData &project)
 
     QStringList untrackedFilesInProject = allFilesInProject(projectDirectory);
     QStringList missingFiles;
-    const auto products = project.allProducts();
-    for (const ProductData &product : products) {
+    for (const ProductData &product : project.allProducts()) {
         qbsInfo() << "\nProduct: " << product.name()
                   << " (" << product.location().filePath() << ":"
                   << product.location().line() << ")";
diff --git a/src/lib/corelib/api/project.cpp b/src/lib/corelib/api/project.cpp
index 2b07f1a8d..c7b6e99e7 100644
--- a/src/lib/corelib/api/project.cpp
+++ b/src/lib/corelib/api/project.cpp
@@ -234,8 +234,7 @@ ResolvedProductPtr ProjectPrivate::internalProduct(const ProductData &product) c
 
 ProductData ProjectPrivate::findProductData(const ProductData &product) const
 {
-    const auto products = m_projectData.allProducts();
-    for (const ProductData &p : products) {
+    for (const ProductData &p : m_projectData.allProducts()) {
         if (p.name() == product.name()
                 && p.profile() == product.profile()
                 && p.multiplexConfigurationId() == product.multiplexConfigurationId()) {
@@ -248,8 +247,7 @@ ProductData ProjectPrivate::findProductData(const ProductData &product) const
 QList<ProductData> ProjectPrivate::findProductsByName(const QString &name) const
 {
     QList<ProductData> list;
-    const auto products = m_projectData.allProducts();
-    for (const ProductData &p : products) {
+    for (const ProductData &p : m_projectData.allProducts()) {
         if (p.name() == name)
             list.push_back(p);
     }
@@ -596,8 +594,7 @@ ProjectTransformerData ProjectPrivate::transformerData()
     if (!m_projectData.isValid())
         retrieveProjectData(m_projectData, internalProject);
     ProjectTransformerData projectTransformerData;
-    const auto allProducts = m_projectData.allProducts();
-    for (const ProductData &productData : allProducts) {
+    for (const ProductData &productData : m_projectData.allProducts()) {
         if (!productData.isEnabled())
             continue;
         const ResolvedProductConstPtr product = internalProduct(productData);
diff --git a/src/lib/corelib/api/projectdata.cpp b/src/lib/corelib/api/projectdata.cpp
index 7c64bf6ff..f15dd63a2 100644
--- a/src/lib/corelib/api/projectdata.cpp
+++ b/src/lib/corelib/api/projectdata.cpp
@@ -812,7 +812,7 @@ QJsonObject ProjectData::toJson(const QStringList &moduleProperties) const
 /*!
  * \brief The name of this project.
  */
-QString ProjectData::name() const
+const QString &ProjectData::name() const
 {
     return d->name;
 }
@@ -820,7 +820,7 @@ QString ProjectData::name() const
 /*!
  * \brief The location at which the project is defined in a qbs source file.
  */
-CodeLocation ProjectData::location() const
+const CodeLocation &ProjectData::location() const
 {
     return d->location;
 }
@@ -839,7 +839,7 @@ bool ProjectData::isEnabled() const
  * \brief The base directory under which the build artifacts of this project will be created.
  * This is only valid for the top-level project.
  */
-QString ProjectData::buildDirectory() const
+const QString &ProjectData::buildDirectory() const
 {
     return d->buildDir;
 }
@@ -848,7 +848,7 @@ QString ProjectData::buildDirectory() const
  * The products in this project.
  * \note This also includes disabled products.
  */
-QList<ProductData> ProjectData::products() const
+const QList<ProductData> &ProjectData::products() const
 {
     return d->products;
 }
@@ -856,7 +856,7 @@ QList<ProductData> ProjectData::products() const
 /*!
  * The sub-projects of this project.
  */
-QList<ProjectData> ProjectData::subProjects() const
+const QList<ProjectData> &ProjectData::subProjects() const
 {
     return d->subProjects;
 }
@@ -864,7 +864,7 @@ QList<ProjectData> ProjectData::subProjects() const
 /*!
  * All products in this projects and its direct and indirect sub-projects.
  */
-QList<ProductData> ProjectData::allProducts() const
+const QList<ProductData> ProjectData::allProducts() const
 {
     QList<ProductData> productList = products();
     for (const ProjectData &pd : qAsConst(d->subProjects))
@@ -875,7 +875,7 @@ QList<ProductData> ProjectData::allProducts() const
 /*!
  * The artifacts of all products in this project that are to be installed.
  */
-QList<ArtifactData> ProjectData::installableArtifacts() const
+const QList<ArtifactData> ProjectData::installableArtifacts() const
 {
     QList<ArtifactData> artifacts;
     const auto products = allProducts();
diff --git a/src/lib/corelib/api/projectdata.h b/src/lib/corelib/api/projectdata.h
index a285f8570..2e6785010 100644
--- a/src/lib/corelib/api/projectdata.h
+++ b/src/lib/corelib/api/projectdata.h
@@ -241,14 +241,14 @@ public:
     bool isValid() const;
     QJsonObject toJson(const QStringList &moduleProperties = {}) const;
 
-    QString name() const;
-    CodeLocation location() const;
+    const QString &name() const;
+    const CodeLocation &location() const;
     bool isEnabled() const;
-    QString buildDirectory() const;
-    QList<ProductData> products() const;
-    QList<ProjectData> subProjects() const;
-    QList<ProductData> allProducts() const;
-    QList<ArtifactData> installableArtifacts() const;
+    const QString &buildDirectory() const;
+    const QList<ProductData> &products() const;
+    const QList<ProjectData> &subProjects() const;
+    const QList<ProductData> allProducts() const;
+    const QList<ArtifactData> installableArtifacts() const;
 
 private:
     QExplicitlySharedDataPointer<Internal::ProjectDataPrivate> d;
diff --git a/src/plugins/generator/clangcompilationdb/clangcompilationdbgenerator.cpp b/src/plugins/generator/clangcompilationdb/clangcompilationdbgenerator.cpp
index 93be2804b..d73cd49a6 100644
--- a/src/plugins/generator/clangcompilationdb/clangcompilationdbgenerator.cpp
+++ b/src/plugins/generator/clangcompilationdb/clangcompilationdbgenerator.cpp
@@ -71,10 +71,9 @@ void ClangCompilationDatabaseGenerator::generate()
     for (const Project &theProject : projects) {
         QJsonArray database;
         const ProjectData projectData = theProject.projectData();
-        const QString buildDir = projectData.buildDirectory();
+        const QString &buildDir = projectData.buildDirectory();
 
-        const auto products = projectData.allProducts();
-        for (const ProductData &productData : products) {
+        for (const ProductData &productData : projectData.allProducts()) {
             const auto groups = productData.groups();
             for (const GroupData &groupData : groups) {
                 const auto sourceArtifacts = groupData.allSourceArtifacts();
diff --git a/src/plugins/generator/makefilegenerator/makefilegenerator.cpp b/src/plugins/generator/makefilegenerator/makefilegenerator.cpp
index 24aff5a33..a158df0ac 100644
--- a/src/plugins/generator/makefilegenerator/makefilegenerator.cpp
+++ b/src/plugins/generator/makefilegenerator/makefilegenerator.cpp
@@ -182,7 +182,7 @@ void qbs::MakefileGenerator::generate()
                                    "is not supported by this generator.").arg(srcDir));
         }
         stream << "SRCDIR = " << QDir::toNativeSeparators(srcDir) << '\n';
-        const QString buildDir = projectData.buildDirectory();
+        const QString &buildDir = projectData.buildDirectory();
         if (buildDir.contains(QLatin1Char(' '))) {
             throw ErrorInfo(Tr::tr("The build directory '%1' contains space characters, which"
                                    "is not supported by this generator.").arg(buildDir));
@@ -293,7 +293,7 @@ void qbs::MakefileGenerator::generate()
             stream << "install-" << productTarget << ": " << productTarget << '\n';
             Set<QString> createdDirs;
             const auto installableArtifacts = productData.installableArtifacts();
-            for (const ArtifactData &artifact : installableArtifacts) {
+            for (const ArtifactData &artifact : productData.installableArtifacts()) {
                 const QString &outputDir = artifact.installData().localInstallDir();
                 if (outputDir.contains(QLatin1Char(' '))) {
                     logger().qbsWarning() << Tr::tr("Skipping installation of '%1', because "