Allow using swiftshader with the Vulkan backend
This adds swiftshader as a dependency of Dawn, and when it is present
dawn_use_swiftshader=true will force usage of it. (due to a Vulkan
loader limitation we can't have both regular drivers and swiftshader in
the same VkInstance).
BUG=dawn:283
Change-Id: Ib94f4dcca652eb380e994f007cdcfb145b1a5102
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/13440
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/build_overrides/swiftshader.gni b/build_overrides/swiftshader.gni
new file mode 100644
index 0000000..4153f72
--- /dev/null
+++ b/build_overrides/swiftshader.gni
@@ -0,0 +1,22 @@
+# Copyright 2019 The Dawn Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# We are building SwiftShader inside Dawn
+swiftshader_standalone = false
+
+# Path to SwiftShader
+swiftshader_dir = "//third_party/swiftshader"
+
+# Paths to SwiftShader dependencies in Dawn
+swiftshader_spirv_tools_dir = "//third_party/SPIRV-Tools"
