Quick: Sanitize reading environment variables.

Where possible, use qEnvironmentVariableIsSet()/
qEnvironmentVariableIsEmpty() instead of checking on the
return value of qgetenv().
Where the value is required, add a check using one of
qEnvironmentVariableIsSet()/Empty().

Move QSGAtlasTexture::qsg_envInt() to qsgrenderer.cpp
for reuse as qt_sg_envInt() and add qt_sg_envFloat().

Change-Id: I4c93f16c228d4f537154f389a0fa1427654485f7
Reviewed-by: Gunnar Sletta <gunnar@sletta.org>

4 files changed, 24 insertions, 26 deletions

diff --git a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
index 60ada14c32..66a8f6fbd3 100644
--- a/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgbatchrenderer.cpp
@@ -61,6 +61,8 @@ QT_BEGIN_NAMESPACE
 
 extern QByteArray qsgShaderRewriter_insertZAttributes(const char *input, QSurfaceFormat::OpenGLContextProfile profile);
 
+int qt_sg_envInt(const char *name, int defaultValue);
+
 namespace QSGBatchRenderer
 {
 
@@ -785,30 +787,17 @@ Renderer::Renderer(QSGRenderContext *ctx)
     }
 
     m_bufferStrategy = GL_STATIC_DRAW;
-    QByteArray strategy = qgetenv("QSG_RENDERER_BUFFER_STRATEGY");
-    if (strategy == "dynamic") {
-        m_bufferStrategy = GL_DYNAMIC_DRAW;
-    } else if (strategy == "stream") {
-        m_bufferStrategy = GL_STREAM_DRAW;
-    }
-
-    m_batchNodeThreshold = 64;
-    QByteArray alternateThreshold = qgetenv("QSG_RENDERER_BATCH_NODE_THRESHOLD");
-    if (alternateThreshold.length() > 0) {
-        bool ok = false;
-        int threshold = alternateThreshold.toInt(&ok);
-        if (ok)
-            m_batchNodeThreshold = threshold;
-    }
-
-    m_batchVertexThreshold = 1024;
-    alternateThreshold = qgetenv("QSG_RENDERER_BATCH_VERTEX_THRESHOLD");
-    if (alternateThreshold.length() > 0) {
-        bool ok = false;
-        int threshold = alternateThreshold.toInt(&ok);
-        if (ok)
-            m_batchVertexThreshold = threshold;
+    if (Q_UNLIKELY(qEnvironmentVariableIsSet("QSG_RENDERER_BUFFER_STRATEGY"))) {
+        const QByteArray strategy = qgetenv("QSG_RENDERER_BUFFER_STRATEGY");
+        if (strategy == "dynamic")
+            m_bufferStrategy = GL_DYNAMIC_DRAW;
+        else if (strategy == "stream")
+            m_bufferStrategy = GL_STREAM_DRAW;
     }
+
+    m_batchNodeThreshold = qt_sg_envInt("QSG_RENDERER_BATCH_NODE_THRESHOLD", 64);
+    m_batchVertexThreshold = qt_sg_envInt("QSG_RENDERER_BATCH_VERTEX_THRESHOLD", 1024);
+
     if (Q_UNLIKELY(debug_build() || debug_render())) {
         qDebug() << "Batch thresholds: nodes:" << m_batchNodeThreshold << " vertices:" << m_batchVertexThreshold;
         qDebug() << "Using buffer strategy:" << (m_bufferStrategy == GL_STATIC_DRAW ? "static" : (m_bufferStrategy == GL_DYNAMIC_DRAW ? "dynamic" : "stream"));
diff --git a/src/quick/scenegraph/coreapi/qsgmaterial.cpp b/src/quick/scenegraph/coreapi/qsgmaterial.cpp
index c68c0b93d2..633cab8078 100644
--- a/src/quick/scenegraph/coreapi/qsgmaterial.cpp
+++ b/src/quick/scenegraph/coreapi/qsgmaterial.cpp
@@ -64,7 +64,7 @@ const char *QSGMaterialShaderPrivate::loadShaderSource(QOpenGLShader::ShaderType
 }
 
 #ifndef QT_NO_DEBUG
-static bool qsg_leak_check = !qgetenv("QML_LEAK_CHECK").isEmpty();
+static const bool qsg_leak_check = !qEnvironmentVariableIsEmpty("QML_LEAK_CHECK");
 #endif
 
 /*!
diff --git a/src/quick/scenegraph/coreapi/qsgnode.cpp b/src/quick/scenegraph/coreapi/qsgnode.cpp
index 51f3976ed9..c09af7c0a3 100644
--- a/src/quick/scenegraph/coreapi/qsgnode.cpp
+++ b/src/quick/scenegraph/coreapi/qsgnode.cpp
@@ -42,7 +42,7 @@
 QT_BEGIN_NAMESPACE
 
 #ifndef QT_NO_DEBUG
-static bool qsg_leak_check = !qgetenv("QML_LEAK_CHECK").isEmpty();
+static const bool qsg_leak_check = !qEnvironmentVariableIsEmpty("QML_LEAK_CHECK");
 static int qt_node_count = 0;
 
 static void qt_print_node_count()
diff --git a/src/quick/scenegraph/coreapi/qsgrenderer.cpp b/src/quick/scenegraph/coreapi/qsgrenderer.cpp
index a9752cb9a9..775277e588 100644
--- a/src/quick/scenegraph/coreapi/qsgrenderer.cpp
+++ b/src/quick/scenegraph/coreapi/qsgrenderer.cpp
@@ -40,12 +40,21 @@
 
 QT_BEGIN_NAMESPACE
 
-static bool qsg_sanity_check = qgetenv("QSG_SANITY_CHECK").toInt();
+static const bool qsg_sanity_check = qEnvironmentVariableIntValue("QSG_SANITY_CHECK");
 
 static QElapsedTimer frameTimer;
 static qint64 preprocessTime;
 static qint64 updatePassTime;
 
+int qt_sg_envInt(const char *name, int defaultValue)
+{
+    if (Q_LIKELY(!qEnvironmentVariableIsSet(name)))
+        return defaultValue;
+    bool ok = false;
+    int value = qgetenv(name).toInt(&ok);
+    return ok ? value : defaultValue;
+}
+
 void QSGBindable::clear(QSGAbstractRenderer::ClearMode mode) const
 {
     GLuint bits = 0;