initial checkin of SkSL compiler

src/gpu/vk/GrVkPipelineStateBuilder.cpp

Index: src/gpu/vk/GrVkPipelineStateBuilder.cpp
diff --git a/src/gpu/vk/GrVkPipelineStateBuilder.cpp b/src/gpu/vk/GrVkPipelineStateBuilder.cpp
index a191505a38c89375626622625305b3629278c94a..323ea669463c35b1b897194d54f4ecdbe1a5f3ac 100644
--- a/src/gpu/vk/GrVkPipelineStateBuilder.cpp
+++ b/src/gpu/vk/GrVkPipelineStateBuilder.cpp
@@ -9,6 +9,9 @@
 
 #include "vk/GrVkGpu.h"
 #include "vk/GrVkRenderPass.h"
+#if USE_SKSL
+#include "SkSLCompiler.h"
+#endif
 
 GrVkPipelineState* GrVkPipelineStateBuilder::CreatePipelineState(
                                                                GrVkGpu* gpu,
@@ -72,6 +75,15 @@ VkShaderStageFlags visibility_to_vk_stage_flags(uint32_t visibility) {
     return flags;
 }
 
+#if USE_SKSL
+SkSL::Program::Kind vk_shader_stage_to_skiasl_kind(VkShaderStageFlagBits stage) {
+    if (VK_SHADER_STAGE_VERTEX_BIT == stage) {
+        return SkSL::Program::kVertex_Kind;
+    }
+    SkASSERT(VK_SHADER_STAGE_FRAGMENT_BIT == stage);
+    return SkSL::Program::kFragment_Kind;
+}
+#else
 shaderc_shader_kind vk_shader_stage_to_shaderc_kind(VkShaderStageFlagBits stage) {
     if (VK_SHADER_STAGE_VERTEX_BIT == stage) {
         return shaderc_glsl_vertex_shader;
@@ -79,7 +91,10 @@ shaderc_shader_kind vk_shader_stage_to_shaderc_kind(VkShaderStageFlagBits stage)
     SkASSERT(VK_SHADER_STAGE_FRAGMENT_BIT == stage);
     return shaderc_glsl_fragment_shader;
 }
+#endif
 
+#include <fstream>
+#include <sstream>
 bool GrVkPipelineStateBuilder::CreateVkShaderModule(const GrVkGpu* gpu,
                                                     VkShaderStageFlagBits stage,
                                                     const GrGLSLShaderBuilder& builder,
@@ -99,13 +114,28 @@ bool GrVkPipelineStateBuilder::CreateVkShaderModule(const GrVkGpu* gpu,
     moduleCreateInfo.pNext = nullptr;
     moduleCreateInfo.flags = 0;
 
+#if USE_SKSL
+    std::string code;
+#else
     shaderc_compilation_result_t result = nullptr;
+#endif
 
     if (gpu->vkCaps().canUseGLSLForShaderModule()) {
         moduleCreateInfo.codeSize = strlen(shaderString.c_str());
         moduleCreateInfo.pCode = (const uint32_t*)shaderString.c_str();
     } else {
 
+#if USE_SKSL
+        bool result = gpu->shaderCompiler()->toSPIRV(vk_shader_stage_to_skiasl_kind(stage), 
+                                                     std::string(shaderString.c_str()),
+                                                     &code);
+        if (!result) {
+            SkDebugf("%s\n", gpu->shaderCompiler()->errorText().c_str());
+            return false;
+        }
+        moduleCreateInfo.codeSize = code.size();
+        moduleCreateInfo.pCode = (const uint32_t*) code.c_str();
+#else
         shaderc_compiler_t compiler = gpu->shadercCompiler();
 
         shaderc_compile_options_t options = shaderc_compile_options_initialize();
@@ -125,18 +155,22 @@ bool GrVkPipelineStateBuilder::CreateVkShaderModule(const GrVkGpu* gpu,
             SkDebugf("%s\n", shaderc_result_get_error_message(result));
             return false;
         }
-#endif
+#endif // SK_DEBUG
 
         moduleCreateInfo.codeSize = shaderc_result_get_length(result);
         moduleCreateInfo.pCode = (const uint32_t*)shaderc_result_get_bytes(result);
+#endif // USE_SKSL
     }
 
     VkResult err = GR_VK_CALL(gpu->vkInterface(), CreateShaderModule(gpu->device(),
                                                                      &moduleCreateInfo,
                                                                      nullptr,
                                                                      shaderModule));
+
     if (!gpu->vkCaps().canUseGLSLForShaderModule()) {
+#if !USE_SKSL
         shaderc_result_release(result);
+#endif
     }
     if (err) {
         return false;