rhi: sanityCheckGraphicsPipeline handle no vertex attributes

It is a valid use case to have a vertex shader with no
vertex attributes. Using gl_VertexID or gl_InstanceID
is enough to generate vertex data out of thin air.

Change-Id: If7689914624a84723923fd2d7aef355bda592e24
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

2 files changed, 1 insertions, 14 deletions

diff --git a/src/gui/rhi/qrhi.cpp b/src/gui/rhi/qrhi.cpp
index 76d6622eda..f2c2ad2284 100644
--- a/src/gui/rhi/qrhi.cpp
+++ b/src/gui/rhi/qrhi.cpp
@@ -4301,14 +4301,8 @@ bool QRhiImplementation::sanityCheckGraphicsPipeline(QRhiGraphicsPipeline *ps)
             qWarning("Empty shader passed to graphics pipeline");
             return false;
         }
-        if (it->type() == QRhiShaderStage::Vertex) {
+        if (it->type() == QRhiShaderStage::Vertex)
             hasVertexStage = true;
-            const QRhiVertexInputLayout inputLayout = ps->vertexInputLayout();
-            if (inputLayout.cbeginAttributes() == inputLayout.cendAttributes()) {
-                qWarning("Vertex stage present without any vertex inputs");
-                return false;
-            }
-        }
     }
     if (!hasVertexStage) {
         qWarning("Cannot build a graphics pipeline without a vertex stage");
diff --git a/tests/auto/gui/rhi/qrhi/tst_qrhi.cpp b/tests/auto/gui/rhi/qrhi/tst_qrhi.cpp
index f5e178de4b..a20bea7ace 100644
--- a/tests/auto/gui/rhi/qrhi/tst_qrhi.cpp
+++ b/tests/auto/gui/rhi/qrhi/tst_qrhi.cpp
@@ -1338,13 +1338,6 @@ void tst_QRhi::invalidPipeline()
     pipeline->setRenderPassDescriptor(rpDesc.data());
     QVERIFY(!pipeline->create());
 
-    // no vertex inputs
-    pipeline.reset(rhi->newGraphicsPipeline());
-    pipeline->setShaderStages({ { QRhiShaderStage::Vertex, vs }, { QRhiShaderStage::Fragment, fs } });
-    pipeline->setRenderPassDescriptor(rpDesc.data());
-    pipeline->setShaderResourceBindings(srb.data());
-    QVERIFY(!pipeline->create());
-
     // no renderpass descriptor
     pipeline.reset(rhi->newGraphicsPipeline());
     pipeline->setShaderStages({ { QRhiShaderStage::Vertex, vs }, { QRhiShaderStage::Fragment, fs } });