Add support for GLSL source-level debugging with RenderDoc (`--generate-spirv-debug-info`)

core/config/engine.cpp

@@ -239,6 +239,10 @@ bool Engine::is_validation_layers_enabled() const {
 	return use_validation_layers;
 }
 
+bool Engine::is_generate_spirv_debug_info_enabled() const {
+	return generate_spirv_debug_info;
+}
+
 void Engine::set_print_error_messages(bool p_enabled) {
 	CoreGlobals::print_error_enabled = p_enabled;
 }

core/config/engine.h

@@ -67,6 +67,7 @@ private:
 	double _physics_interpolation_fraction = 0.0f;
 	bool abort_on_gpu_errors = false;
 	bool use_validation_layers = false;
+	bool generate_spirv_debug_info = false;
 	int32_t gpu_idx = -1;
 
 	uint64_t _process_frames = 0;
@@ -156,6 +157,7 @@ public:
 
 	bool is_abort_on_gpu_errors_enabled() const;
 	bool is_validation_layers_enabled() const;
+	bool is_generate_spirv_debug_info_enabled() const;
 	int32_t get_gpu_index() const;
 
 	Engine();

drivers/vulkan/vulkan_context.cpp

@@ -504,6 +504,10 @@ Error VulkanContext::_initialize_device_extensions() {
 	register_requested_device_extension(VK_KHR_IMAGE_FORMAT_LIST_EXTENSION_NAME, false);
 	register_requested_device_extension(VK_KHR_MAINTENANCE_2_EXTENSION_NAME, false);
 
+	if (Engine::get_singleton()->is_generate_spirv_debug_info_enabled()) {
+		register_requested_device_extension(VK_KHR_SHADER_NON_SEMANTIC_INFO_EXTENSION_NAME, true);
+	}
+
 	// TODO consider the following extensions:
 	// - VK_KHR_spirv_1_4
 	// - VK_KHR_swapchain_mutable_format

main/main.cpp

@@ -458,6 +458,7 @@ void Main::print_help(const char *p_binary) {
 #if DEBUG_ENABLED
 	OS::get_singleton()->print("  --gpu-abort                       Abort on graphics API usage errors (usually validation layer errors). May help see the problem if your system freezes.\n");
 #endif
+	OS::get_singleton()->print("  --generate-spirv-debug-info       Generate SPIR-V debug information. This allows source-level shader debugging with RenderDoc.\n");
 	OS::get_singleton()->print("  --remote-debug <uri>              Remote debug (<protocol>://<host/IP>[:<port>], e.g. tcp://127.0.0.1:6007).\n");
 	OS::get_singleton()->print("  --single-threaded-scene           Scene tree runs in single-threaded mode. Sub-thread groups are disabled and run on the main thread.\n");
 #if defined(DEBUG_ENABLED)
@@ -1019,6 +1020,8 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 		} else if (I->get() == "--gpu-abort") {
 			Engine::singleton->abort_on_gpu_errors = true;
 #endif
+		} else if (I->get() == "--generate-spirv-debug-info") {
+			Engine::singleton->generate_spirv_debug_info = true;
 		} else if (I->get() == "--tablet-driver") {
 			if (I->next()) {
 				tablet_driver = I->next()->get();

modules/glslang/register_types.cpp

@@ -32,6 +32,7 @@
 
 #include "glslang_resource_limits.h"
 
+#include "core/config/engine.h"
 #include "servers/rendering/rendering_device.h"
 
 #include <glslang/Include/Types.h>
@@ -56,7 +57,6 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 
 	glslang::EShTargetClientVersion ClientVersion = glslang::EShTargetVulkan_1_2;
 	glslang::EShTargetLanguageVersion TargetVersion = glslang::EShTargetSpv_1_5;
-	glslang::TShader::ForbidIncluder includer;
 
 	if (capabilities->device_family == RenderingDevice::DeviceFamily::DEVICE_VULKAN) {
 		if (capabilities->version_major == 1 && capabilities->version_minor == 0) {
@@ -127,23 +127,10 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 	}
 
 	EShMessages messages = (EShMessages)(EShMsgSpvRules | EShMsgVulkanRules);
-	const int DefaultVersion = 100;
-	std::string pre_processed_code;
-
-	//preprocess
-	if (!shader.preprocess(&DefaultTBuiltInResource, DefaultVersion, ENoProfile, false, false, messages, &pre_processed_code, includer)) {
-		if (r_error) {
-			(*r_error) = "Failed pre-process:\n";
-			(*r_error) += shader.getInfoLog();
-			(*r_error) += "\n";
-			(*r_error) += shader.getInfoDebugLog();
-		}
-
-		return ret;
+	if (Engine::get_singleton()->is_generate_spirv_debug_info_enabled()) {
+		messages = (EShMessages)(messages | EShMsgDebugInfo);
 	}
-	//set back..
-	cs_strings = pre_processed_code.c_str();
-	shader.setStrings(&cs_strings, 1);
+	const int DefaultVersion = 100;
 
 	//parse
 	if (!shader.parse(&DefaultTBuiltInResource, DefaultVersion, false, messages)) {
@@ -174,6 +161,13 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 	std::vector<uint32_t> SpirV;
 	spv::SpvBuildLogger logger;
 	glslang::SpvOptions spvOptions;
+
+	if (Engine::get_singleton()->is_generate_spirv_debug_info_enabled()) {
+		spvOptions.generateDebugInfo = true;
+		spvOptions.emitNonSemanticShaderDebugInfo = true;
+		spvOptions.emitNonSemanticShaderDebugSource = true;
+	}
+
 	glslang::GlslangToSpv(*program.getIntermediate(stages[p_stage]), SpirV, &logger, &spvOptions);
 
 	ret.resize(SpirV.size() * sizeof(uint32_t));
@@ -188,7 +182,7 @@ static Vector<uint8_t> _compile_shader_glsl(RenderingDevice::ShaderStage p_stage
 static String _get_cache_key_function_glsl(const RenderingDevice *p_render_device) {
 	const RD::Capabilities *capabilities = p_render_device->get_device_capabilities();
 	String version;
-	version = "SpirVGen=" + itos(glslang::GetSpirvGeneratorVersion()) + ", major=" + itos(capabilities->version_major) + ", minor=" + itos(capabilities->version_minor) + " , subgroup_size=" + itos(p_render_device->limit_get(RD::LIMIT_SUBGROUP_SIZE)) + " , subgroup_ops=" + itos(p_render_device->limit_get(RD::LIMIT_SUBGROUP_OPERATIONS)) + " , subgroup_in_shaders=" + itos(p_render_device->limit_get(RD::LIMIT_SUBGROUP_IN_SHADERS));
+	version = "SpirVGen=" + itos(glslang::GetSpirvGeneratorVersion()) + ", major=" + itos(capabilities->version_major) + ", minor=" + itos(capabilities->version_minor) + " , subgroup_size=" + itos(p_render_device->limit_get(RD::LIMIT_SUBGROUP_SIZE)) + " , subgroup_ops=" + itos(p_render_device->limit_get(RD::LIMIT_SUBGROUP_OPERATIONS)) + " , subgroup_in_shaders=" + itos(p_render_device->limit_get(RD::LIMIT_SUBGROUP_IN_SHADERS)) + " , debug=" + itos(Engine::get_singleton()->is_generate_spirv_debug_info_enabled());
 	return version;
 }