Merge pull request #4698 from lioncash/optional-null

General: Make use of std::nullopt where applicable

src/core/arm/dynarmic/arm_dynarmic_cp15.cpp

@@ -34,7 +34,7 @@ std::optional<Callback> DynarmicCP15::CompileInternalOperation(bool two, unsigne
                                                                CoprocReg CRm, unsigned opc2) {
     LOG_CRITICAL(Core_ARM, "CP15: cdp{} p15, {}, {}, {}, {}, {}", two ? "2" : "", opc1, CRd, CRn,
                  CRm, opc2);
-    return {};
+    return std::nullopt;
 }
 
 CallbackOrAccessOneWord DynarmicCP15::CompileSendOneWord(bool two, unsigned opc1, CoprocReg CRn,
@@ -115,7 +115,7 @@ std::optional<Callback> DynarmicCP15::CompileLoadWords(bool two, bool long_trans
         LOG_CRITICAL(Core_ARM, "CP15: mrrc{}{} p15, {}, [...]", two ? "2" : "",
                      long_transfer ? "l" : "", CRd);
     }
-    return {};
+    return std::nullopt;
 }
 
 std::optional<Callback> DynarmicCP15::CompileStoreWords(bool two, bool long_transfer, CoprocReg CRd,
@@ -127,7 +127,7 @@ std::optional<Callback> DynarmicCP15::CompileStoreWords(bool two, bool long_tran
         LOG_CRITICAL(Core_ARM, "CP15: mrrc{}{} p15, {}, [...]", two ? "2" : "",
                      long_transfer ? "l" : "", CRd);
     }
-    return {};
+    return std::nullopt;
 }
 
 } // namespace Core

src/core/file_sys/content_archive.cpp

@@ -323,7 +323,7 @@ bool NCA::ReadRomFSSection(const NCASectionHeader& section, const NCASectionTabl
         subsection_buckets.back().entries.push_back({section.bktr.relocation.offset, {0}, ctr_low});
         subsection_buckets.back().entries.push_back({size, {0}, 0});
 
-        std::optional<Core::Crypto::Key128> key = {};
+        std::optional<Core::Crypto::Key128> key;
         if (encrypted) {
             if (has_rights_id) {
                 status = Loader::ResultStatus::Success;
@@ -442,18 +442,18 @@ std::optional<Core::Crypto::Key128> NCA::GetTitlekey() {
     memcpy(rights_id.data(), header.rights_id.data(), 16);
     if (rights_id == u128{}) {
         status = Loader::ResultStatus::ErrorInvalidRightsID;
-        return {};
+        return std::nullopt;
     }
 
     auto titlekey = keys.GetKey(Core::Crypto::S128KeyType::Titlekey, rights_id[1], rights_id[0]);
     if (titlekey == Core::Crypto::Key128{}) {
         status = Loader::ResultStatus::ErrorMissingTitlekey;
-        return {};
+        return std::nullopt;
     }
 
     if (!keys.HasKey(Core::Crypto::S128KeyType::Titlekek, master_key_id)) {
         status = Loader::ResultStatus::ErrorMissingTitlekek;
-        return {};
+        return std::nullopt;
     }
 
     Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(
@@ -477,7 +477,7 @@ VirtualFile NCA::Decrypt(const NCASectionHeader& s_header, VirtualFile in, u64 s
     case NCASectionCryptoType::BKTR:
         LOG_TRACE(Crypto, "called with mode=CTR, starting_offset={:016X}", starting_offset);
         {
-            std::optional<Core::Crypto::Key128> key = {};
+            std::optional<Core::Crypto::Key128> key;
             if (has_rights_id) {
                 status = Loader::ResultStatus::Success;
                 key = GetTitlekey();

src/core/file_sys/vfs.cpp

@@ -169,11 +169,12 @@ VfsDirectory::~VfsDirectory() = default;
 
 std::optional<u8> VfsFile::ReadByte(std::size_t offset) const {
     u8 out{};
-    std::size_t size = Read(&out, 1, offset);
-    if (size == 1)
+    const std::size_t size = Read(&out, sizeof(u8), offset);
+    if (size == 1) {
         return out;
+    }
 
-    return {};
+    return std::nullopt;
 }
 
 std::vector<u8> VfsFile::ReadBytes(std::size_t size, std::size_t offset) const {

src/core/file_sys/vfs_offset.cpp

@@ -58,10 +58,11 @@ std::size_t OffsetVfsFile::Write(const u8* data, std::size_t length, std::size_t
 }
 
 std::optional<u8> OffsetVfsFile::ReadByte(std::size_t r_offset) const {
-    if (r_offset < size)
-        return file->ReadByte(offset + r_offset);
+    if (r_offset >= size) {
+        return std::nullopt;
+    }
 
-    return {};
+    return file->ReadByte(offset + r_offset);
 }
 
 std::vector<u8> OffsetVfsFile::ReadBytes(std::size_t r_size, std::size_t r_offset) const {

src/core/file_sys/vfs_static.h

@@ -54,9 +54,11 @@ public:
     }
 
     std::optional<u8> ReadByte(std::size_t offset) const override {
-        if (offset < size)
-            return value;
-        return {};
+        if (offset >= size) {
+            return std::nullopt;
+        }
+
+        return value;
     }
 
     std::vector<u8> ReadBytes(std::size_t length, std::size_t offset) const override {

src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp

@@ -265,7 +265,7 @@ std::optional<nvhost_as_gpu::BufferMap> nvhost_as_gpu::FindBufferMap(GPUVAddr gp
         }
     }
 
-    return {};
+    return std::nullopt;
 }
 
 void nvhost_as_gpu::AddBufferMap(GPUVAddr gpu_addr, std::size_t size, VAddr cpu_addr,
@@ -286,7 +286,7 @@ std::optional<std::size_t> nvhost_as_gpu::RemoveBufferMap(GPUVAddr gpu_addr) {
         return size;
     }
 
-    return {};
+    return std::nullopt;
 }
 
 } // namespace Service::Nvidia::Devices

src/core/hle/service/nvdrv/nvdrv.h

@@ -54,7 +54,7 @@ struct EventInterface {
             }
             mask = mask >> 1;
         }
-        return {};
+        return std::nullopt;
     }
     void SetEventStatus(const u32 event_id, EventState new_status) {
         EventState old_status = status[event_id];

src/core/hle/service/nvflinger/nvflinger.cpp

@@ -114,7 +114,7 @@ std::optional<u64> NVFlinger::OpenDisplay(std::string_view name) {
                      [&](const VI::Display& display) { return display.GetName() == name; });
 
     if (itr == displays.end()) {
-        return {};
+        return std::nullopt;
     }
 
     return itr->GetID();
@@ -124,7 +124,7 @@ std::optional<u64> NVFlinger::CreateLayer(u64 display_id) {
     auto* const display = FindDisplay(display_id);
 
     if (display == nullptr) {
-        return {};
+        return std::nullopt;
     }
 
     const u64 layer_id = next_layer_id++;
@@ -144,7 +144,7 @@ std::optional<u32> NVFlinger::FindBufferQueueId(u64 display_id, u64 layer_id) co
     const auto* const layer = FindLayer(display_id, layer_id);
 
     if (layer == nullptr) {
-        return {};
+        return std::nullopt;
     }
 
     return layer->GetBufferQueue().GetId();

src/core/hle/service/sockets/bsd.cpp

@@ -497,7 +497,7 @@ std::pair<s32, Errno> BSD::PollImpl(std::vector<u8>& write_buffer, std::vector<u
             return {0, Errno::SUCCESS};
         }
 
-        std::optional<FileDescriptor>& descriptor = file_descriptors[pollfd.fd];
+        const std::optional<FileDescriptor>& descriptor = file_descriptors[pollfd.fd];
         if (!descriptor) {
             LOG_ERROR(Service, "File descriptor handle={} is not allocated", pollfd.fd);
             pollfd.revents = POLL_NVAL;

src/core/loader/nso.cpp

@@ -76,16 +76,16 @@ std::optional<VAddr> AppLoader_NSO::LoadModule(Kernel::Process& process, Core::S
                                                bool should_pass_arguments, bool load_into_process,
                                                std::optional<FileSys::PatchManager> pm) {
     if (file.GetSize() < sizeof(NSOHeader)) {
-        return {};
+        return std::nullopt;
     }
 
     NSOHeader nso_header{};
     if (sizeof(NSOHeader) != file.ReadObject(&nso_header)) {
-        return {};
+        return std::nullopt;
     }
 
     if (nso_header.magic != Common::MakeMagic('N', 'S', 'O', '0')) {
-        return {};
+        return std::nullopt;
     }
 
     // Build program image

src/video_core/engines/maxwell_3d.cpp

@@ -597,7 +597,7 @@ std::optional<u64> Maxwell3D::GetQueryResult() {
         // Deferred.
         rasterizer->Query(regs.query.QueryAddress(), VideoCore::QueryType::SamplesPassed,
                           system.GPU().GetTicks());
-        return {};
+        return std::nullopt;
     default:
         LOG_DEBUG(HW_GPU, "Unimplemented query select type {}",
                   static_cast<u32>(regs.query.query_get.select.Value()));

src/video_core/macro/macro.cpp

@@ -36,7 +36,7 @@ void MacroEngine::Execute(Engines::Maxwell3D& maxwell3d, u32 method,
         }
     } else {
         // Macro not compiled, check if it's uploaded and if so, compile it
-        std::optional<u32> mid_method = std::nullopt;
+        std::optional<u32> mid_method;
         const auto macro_code = uploaded_macro_code.find(method);
         if (macro_code == uploaded_macro_code.end()) {
             for (const auto& [method_base, code] : uploaded_macro_code) {

src/video_core/memory_manager.cpp

@@ -58,7 +58,7 @@ void MemoryManager::Unmap(GPUVAddr gpu_addr, std::size_t size) {
 std::optional<GPUVAddr> MemoryManager::AllocateFixed(GPUVAddr gpu_addr, std::size_t size) {
     for (u64 offset{}; offset < size; offset += page_size) {
         if (!GetPageEntry(gpu_addr + offset).IsUnmapped()) {
-            return {};
+            return std::nullopt;
         }
     }
 
@@ -135,13 +135,13 @@ std::optional<GPUVAddr> MemoryManager::FindFreeRange(std::size_t size, std::size
         }
     }
 
-    return {};
+    return std::nullopt;
 }
 
 std::optional<VAddr> MemoryManager::GpuToCpuAddress(GPUVAddr gpu_addr) const {
     const auto page_entry{GetPageEntry(gpu_addr)};
     if (!page_entry.IsValid()) {
-        return {};
+        return std::nullopt;
     }
 
     return page_entry.ToAddress() + (gpu_addr & page_mask);

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -813,7 +813,7 @@ private:
         const u8 location = static_cast<u8>(static_cast<u32>(index) * 4 + element);
         const auto it = transform_feedback.find(location);
         if (it == transform_feedback.end()) {
-            return {};
+            return std::nullopt;
         }
         return it->second.components;
     }
@@ -1295,21 +1295,21 @@ private:
             switch (element) {
             case 0:
                 UNIMPLEMENTED();
-                return {};
+                return std::nullopt;
             case 1:
                 if (stage == ShaderType::Vertex && !device.HasVertexViewportLayer()) {
-                    return {};
+                    return std::nullopt;
                 }
                 return {{"gl_Layer", Type::Int}};
             case 2:
                 if (stage == ShaderType::Vertex && !device.HasVertexViewportLayer()) {
-                    return {};
+                    return std::nullopt;
                 }
                 return {{"gl_ViewportIndex", Type::Int}};
             case 3:
                 return {{"gl_PointSize", Type::Float}};
             }
-            return {};
+            return std::nullopt;
         case Attribute::Index::FrontColor:
             return {{"gl_FrontColor"s + GetSwizzle(element), Type::Float}};
         case Attribute::Index::FrontSecondaryColor:
@@ -1332,7 +1332,7 @@ private:
                          Type::Float}};
             }
             UNIMPLEMENTED_MSG("Unhandled output attribute: {}", static_cast<u32>(attribute));
-            return {};
+            return std::nullopt;
         }
     }
 

src/video_core/shader/ast.h

@@ -199,55 +199,48 @@ public:
     }
 
     std::optional<u32> GetGotoLabel() const {
-        auto inner = std::get_if<ASTGoto>(&data);
-        if (inner) {
+        if (const auto* inner = std::get_if<ASTGoto>(&data)) {
             return {inner->label};
         }
-        return {};
+        return std::nullopt;
     }
 
     Expr GetGotoCondition() const {
-        auto inner = std::get_if<ASTGoto>(&data);
-        if (inner) {
+        if (const auto* inner = std::get_if<ASTGoto>(&data)) {
             return inner->condition;
         }
         return nullptr;
     }
 
     void MarkLabelUnused() {
-        auto inner = std::get_if<ASTLabel>(&data);
-        if (inner) {
+        if (auto* inner = std::get_if<ASTLabel>(&data)) {
             inner->unused = true;
         }
     }
 
     bool IsLabelUnused() const {
-        auto inner = std::get_if<ASTLabel>(&data);
-        if (inner) {
+        if (const auto* inner = std::get_if<ASTLabel>(&data)) {
             return inner->unused;
         }
         return true;
     }
 
     std::optional<u32> GetLabelIndex() const {
-        auto inner = std::get_if<ASTLabel>(&data);
-        if (inner) {
+        if (const auto* inner = std::get_if<ASTLabel>(&data)) {
             return {inner->index};
         }
-        return {};
+        return std::nullopt;
     }
 
     Expr GetIfCondition() const {
-        auto inner = std::get_if<ASTIfThen>(&data);
-        if (inner) {
+        if (const auto* inner = std::get_if<ASTIfThen>(&data)) {
             return inner->condition;
         }
         return nullptr;
     }
 
     void SetGotoCondition(Expr new_condition) {
-        auto inner = std::get_if<ASTGoto>(&data);
-        if (inner) {
+        if (auto* inner = std::get_if<ASTGoto>(&data)) {
             inner->condition = std::move(new_condition);
         }
     }

src/video_core/shader/track.cpp

@@ -205,12 +205,12 @@ std::optional<u32> ShaderIR::TrackImmediate(Node tracked, const NodeBlock& code,
     const auto result = TrackRegister(&std::get<GprNode>(*tracked), code, cursor - 1);
     const auto& found = result.first;
     if (!found) {
-        return {};
+        return std::nullopt;
     }
     if (const auto immediate = std::get_if<ImmediateNode>(&*found)) {
         return immediate->GetValue();
     }
-    return {};
+    return std::nullopt;
 }
 
 std::pair<Node, s64> ShaderIR::TrackRegister(const GprNode* tracked, const NodeBlock& code,

src/video_core/texture_cache/surface_base.cpp

@@ -115,20 +115,24 @@ std::optional<std::pair<u32, u32>> SurfaceBaseImpl::GetLayerMipmap(
     if (gpu_addr == candidate_gpu_addr) {
         return {{0, 0}};
     }
+
     if (candidate_gpu_addr < gpu_addr) {
-        return {};
+        return std::nullopt;
     }
+
     const auto relative_address{static_cast<GPUVAddr>(candidate_gpu_addr - gpu_addr)};
     const auto layer{static_cast<u32>(relative_address / layer_size)};
     if (layer >= params.depth) {
-        return {};
+        return std::nullopt;
     }
+
     const GPUVAddr mipmap_address = relative_address - layer_size * layer;
     const auto mipmap_it =
         Common::BinaryFind(mipmap_offsets.begin(), mipmap_offsets.end(), mipmap_address);
     if (mipmap_it == mipmap_offsets.end()) {
-        return {};
+        return std::nullopt;
     }
+
     const auto level{static_cast<u32>(std::distance(mipmap_offsets.begin(), mipmap_it))};
     return std::make_pair(layer, level);
 }