From 293ea7746d7f5bbb8eade19100df0269003dc79c Mon Sep 17 00:00:00 2001
From: Corentin Wallez <cwallez@chromium.org>
Date: Wed, 26 Jun 2019 20:28:13 +0000
Subject: [PATCH] Make RenderPipeline::ValidateCompatibleWith produce an error
 message

Previously it would only return a boolean which made it difficult to
know why the validation is failing.

BUG=dawn:128

Change-Id: Id129a84f7777ba2efc5f12292aeccb83c076b9af
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/8362
Commit-Queue: Kai Ninomiya <kainino@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
---
 src/dawn_native/CommandEncoder.cpp |  6 +-----
 src/dawn_native/RenderPipeline.cpp | 19 ++++++++++++-------
 src/dawn_native/RenderPipeline.h   |  2 +-
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/dawn_native/CommandEncoder.cpp b/src/dawn_native/CommandEncoder.cpp
index b20dbc4064..300e832256 100644
--- a/src/dawn_native/CommandEncoder.cpp
+++ b/src/dawn_native/CommandEncoder.cpp
@@ -1199,11 +1199,7 @@ namespace dawn_native {
                     SetRenderPipelineCmd* cmd = mIterator.NextCommand<SetRenderPipelineCmd>();
                     RenderPipelineBase* pipeline = cmd->pipeline.Get();
 
-                    if (!pipeline->IsCompatibleWith(renderPass)) {
-                        return DAWN_VALIDATION_ERROR(
-                            "Pipeline is incompatible with this render pass");
-                    }
-
+                    DAWN_TRY(pipeline->ValidateCompatibleWith(renderPass));
                     persistentState.SetRenderPipeline(pipeline);
                 } break;
 
diff --git a/src/dawn_native/RenderPipeline.cpp b/src/dawn_native/RenderPipeline.cpp
index 7e85287c1e..cd82a83bbc 100644
--- a/src/dawn_native/RenderPipeline.cpp
+++ b/src/dawn_native/RenderPipeline.cpp
@@ -492,38 +492,43 @@ namespace dawn_native {
         return mSampleCount;
     }
 
-    bool RenderPipelineBase::IsCompatibleWith(const BeginRenderPassCmd* renderPass) const {
+    MaybeError RenderPipelineBase::ValidateCompatibleWith(
+        const BeginRenderPassCmd* renderPass) const {
         ASSERT(!IsError());
         // TODO(cwallez@chromium.org): This is called on every SetPipeline command. Optimize it for
         // example by caching some "attachment compatibility" object that would make the
         // compatibility check a single pointer comparison.
 
         if (renderPass->colorAttachmentsSet != mColorAttachmentsSet) {
-            return false;
+            return DAWN_VALIDATION_ERROR(
+                "Pipeline doesn't have same color attachments set as renderPass");
         }
 
         for (uint32_t i : IterateBitSet(mColorAttachmentsSet)) {
             if (renderPass->colorAttachments[i].view->GetFormat().format !=
                 mColorStates[i].format) {
-                return false;
+                return DAWN_VALIDATION_ERROR(
+                    "Pipeline color attachment format doesn't match renderPass");
             }
         }
 
         if (renderPass->hasDepthStencilAttachment != mHasDepthStencilAttachment) {
-            return false;
+            return DAWN_VALIDATION_ERROR(
+                "Pipeline depth stencil attachment doesn't match renderPass");
         }
 
         if (mHasDepthStencilAttachment &&
             (renderPass->depthStencilAttachment.view->GetFormat().format !=
              mDepthStencilState.format)) {
-            return false;
+            return DAWN_VALIDATION_ERROR(
+                "Pipeline depth stencil attachment format doesn't match renderPass");
         }
 
         if (renderPass->sampleCount != mSampleCount) {
-            return false;
+            return DAWN_VALIDATION_ERROR("Pipeline sample count doesn't match renderPass");
         }
 
-        return true;
+        return {};
     }
 
     std::bitset<kMaxVertexAttributes> RenderPipelineBase::GetAttributesUsingInput(
diff --git a/src/dawn_native/RenderPipeline.h b/src/dawn_native/RenderPipeline.h
index 0f33fa6718..fd951e49c9 100644
--- a/src/dawn_native/RenderPipeline.h
+++ b/src/dawn_native/RenderPipeline.h
@@ -79,7 +79,7 @@ namespace dawn_native {
 
         // A pipeline can be used in a render pass if its attachment info matches the actual
         // attachments in the render pass. This returns whether it is the case.
-        bool IsCompatibleWith(const BeginRenderPassCmd* renderPassCmd) const;
+        MaybeError ValidateCompatibleWith(const BeginRenderPassCmd* renderPassCmd) const;
         std::bitset<kMaxVertexAttributes> GetAttributesUsingInput(uint32_t slot) const;
         std::array<std::bitset<kMaxVertexAttributes>, kMaxVertexBuffers> attributesUsingInput;