[cheats] add runtime cheats toggles with master code support (#4334)

add per-cheat runtime toggles (thread-safe).
add master code handling (master code cannot be disabled, as noted in Atmosphere's implementation).
add configurable global / per-game initial states for cheat entries.
remove fixed opcode limits and do some fixes to text parsing / file loading.
do not run debug log while cheat logging is not enabled, to reduce performance impacts.
update the `Using Cheats` document to reflect the changes.

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4334
Reviewed-by: lizzie <lizzie@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: John <john@eden-emu.dev>

src/core/core.cpp

@@ -786,6 +786,17 @@ void System::RegisterCheatList(const std::vector<Memory::CheatEntry>& list,
     impl->cheat_engine->SetMainMemoryParameters(main_region_begin, main_region_size);
 }
 
+std::vector<Memory::RuntimeCheatInfo> System::GetRuntimeCheats() const {
+    if (!impl->cheat_engine) {
+        return {};
+    }
+    return impl->cheat_engine->GetCheats();
+}
+
+bool System::SetCheatEnabled(u32 cheat_id, bool enabled) {
+    return impl->cheat_engine && impl->cheat_engine->SetCheatEnabled(cheat_id, enabled);
+}
+
 void System::SetFrontendAppletSet(Service::AM::Frontend::FrontendAppletSet&& set) {
     impl->frontend_applets.SetFrontendAppletSet(std::move(set));
 }

src/core/core.h

@@ -46,6 +46,7 @@ enum class ResultStatus : u16;
 
 namespace Core::Memory {
 struct CheatEntry;
+struct RuntimeCheatInfo;
 class Memory;
 } // namespace Core::Memory
 
@@ -342,6 +343,8 @@ public:
     void RegisterCheatList(const std::vector<Memory::CheatEntry>& list,
                            const std::array<u8, 0x20>& build_id, u64 main_region_begin,
                            u64 main_region_size);
+    [[nodiscard]] std::vector<Memory::RuntimeCheatInfo> GetRuntimeCheats() const;
+    bool SetCheatEnabled(u32 cheat_id, bool enabled);
 
     void SetFrontendAppletSet(Service::AM::Frontend::FrontendAppletSet&& set);
 

src/core/file_sys/patch_manager.cpp

@@ -503,10 +503,11 @@ std::vector<Core::Memory::CheatEntry> PatchManager::CreateCheatList(const BuildI
     for (const auto& subdir : patch_dirs) {
         if (std::find(disabled.cbegin(), disabled.cend(), subdir->GetName()) == disabled.cend()) {
             if (auto cheats_dir = FindSubdirectoryCaseless(subdir, "cheats"); cheats_dir != nullptr) {
-                if (auto const res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, true))
-                    std::copy(res->begin(), res->end(), std::back_inserter(out));
-                if (auto const res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, false))
+                if (auto const res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, true)) {
                     std::copy(res->begin(), res->end(), std::back_inserter(out));
+                } else if (auto const lower_res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, false)) {
+                    std::copy(lower_res->begin(), lower_res->end(), std::back_inserter(out));
+                }
             }
         }
     }

src/core/memory/cheat_engine.cpp

@@ -4,8 +4,11 @@
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <cctype>
 #include <locale>
 #include "common/hex_util.h"
+#include "common/logging.h"
+#include "common/settings.h"
 #include "common/swap.h"
 #include "core/arm/debug.h"
 #include "core/core.h"
@@ -28,11 +31,11 @@ constexpr auto CHEAT_ENGINE_NS = std::chrono::nanoseconds{1000000000 / 12};
 std::string_view ExtractName(std::size_t& out_name_size, std::string_view data,
                              std::size_t start_index, char match) {
     auto end_index = start_index;
-    while (data[end_index] != match) {
+    while (end_index < data.size() && data[end_index] != match) {
         ++end_index;
-        if (end_index > data.size()) {
-            return {};
-        }
+    }
+    if (end_index == data.size()) {
+        return {};
     }
 
     out_name_size = end_index - start_index;
@@ -130,6 +133,11 @@ void StandardVmCallbacks::CommandLog(std::string_view data) {
               data.back() == '\n' ? data.substr(0, data.size() - 1) : data);
 }
 
+bool StandardVmCallbacks::IsCommandLogEnabled() const {
+    return Common::Log::IsMessageEnabled(Common::Log::Class::CheatEngine,
+                                         Common::Log::Level::Debug);
+}
+
 bool StandardVmCallbacks::IsAddressInRange(VAddr in) const {
     if ((in < metadata.main_nso_extents.base ||
          in >= metadata.main_nso_extents.base + metadata.main_nso_extents.size) &&
@@ -166,8 +174,9 @@ std::vector<CheatEntry> TextCheatParser::Parse(std::string_view data) const {
 
         if (data[i] == '{') {
             current_entry = 0;
+            out[*current_entry].is_master = true;
 
-            if (out[*current_entry].definition.num_opcodes > 0) {
+            if (!out[*current_entry].definition.opcodes.empty()) {
                 return {};
             }
 
@@ -203,32 +212,33 @@ std::vector<CheatEntry> TextCheatParser::Parse(std::string_view data) const {
                 '\0';
 
             i += name_size + 1;
-        } else if (::isxdigit(data[i])) {
-            if (!current_entry || out[*current_entry].definition.num_opcodes >=
-                                      out[*current_entry].definition.opcodes.size()) {
+        } else if (std::isxdigit(static_cast<unsigned char>(data[i]))) {
+            if (!current_entry || data.size() - i < 8) {
                 return {};
             }
 
             const auto hex = std::string(data.substr(i, 8));
-            if (!std::all_of(hex.begin(), hex.end(), ::isxdigit)) {
+            if (!std::all_of(hex.begin(), hex.end(), [](char value) {
+                    return std::isxdigit(static_cast<unsigned char>(value));
+                })) {
                 return {};
             }
 
             const auto value = static_cast<u32>(std::strtoul(hex.c_str(), nullptr, 0x10));
-            out[*current_entry].definition.opcodes[out[*current_entry].definition.num_opcodes++] =
-                value;
+            out[*current_entry].definition.opcodes.push_back(value);
 
-            i += 8;
+            i += 7;
         } else {
             return {};
         }
     }
 
-    out[0].enabled = out[0].definition.num_opcodes > 0;
+    out[0].enabled = out[0].is_master && !out[0].definition.opcodes.empty();
     out[0].cheat_id = 0;
 
     for (u32 i = 1; i < out.size(); ++i) {
-        out[i].enabled = out[i].definition.num_opcodes > 0;
+        out[i].enabled = Settings::values.enable_cheats_by_default.GetValue() &&
+                         !out[i].definition.opcodes.empty();
         out[i].cheat_id = i;
     }
 
@@ -240,6 +250,10 @@ CheatEngine::CheatEngine(System& system_, std::vector<CheatEntry> cheats_,
     : vm{std::make_unique<StandardVmCallbacks>(system_, metadata)},
       cheats(std::move(cheats_)), core_timing{system_.CoreTiming()}, system{system_} {
     metadata.main_nso_build_id = build_id_;
+    for (u32 i = 0; i < cheats.size(); ++i) {
+        cheats[i].cheat_id = i;
+        cheats[i].enabled = cheats[i].is_master || cheats[i].enabled;
+    }
 }
 
 CheatEngine::~CheatEngine() {
@@ -286,12 +300,56 @@ void CheatEngine::SetMainMemoryParameters(VAddr main_region_begin, u64 main_regi
 }
 
 void CheatEngine::Reload(std::vector<CheatEntry> reload_cheats) {
-    cheats = std::move(reload_cheats);
-    is_pending_reload.exchange(true);
+    {
+        std::scoped_lock lock{cheats_mutex};
+        cheats = std::move(reload_cheats);
+        for (u32 i = 0; i < cheats.size(); ++i) {
+            cheats[i].cheat_id = i;
+            cheats[i].enabled = cheats[i].is_master || cheats[i].enabled;
+        }
+    }
+    is_pending_reload.store(true);
+}
+
+std::vector<RuntimeCheatInfo> CheatEngine::GetCheats() const {
+    std::scoped_lock lock{cheats_mutex};
+    std::vector<RuntimeCheatInfo> result;
+    result.reserve(cheats.size());
+    for (const auto& cheat : cheats) {
+        if (cheat.definition.opcodes.empty()) {
+            continue;
+        }
+        result.push_back({
+            .id = cheat.cheat_id,
+            .name = cheat.definition.readable_name.data(),
+            .enabled = cheat.enabled || cheat.is_master,
+            .is_master = cheat.is_master,
+        });
+    }
+    return result;
+}
+
+bool CheatEngine::SetCheatEnabled(u32 cheat_id, bool enabled) {
+    std::scoped_lock lock{cheats_mutex};
+    const auto entry = std::find_if(cheats.begin(), cheats.end(), [cheat_id](const auto& cheat) {
+        return cheat.cheat_id == cheat_id && !cheat.definition.opcodes.empty();
+    });
+    if (entry == cheats.end()) {
+        return false;
+    }
+    if (entry->is_master) {
+        return enabled;
+    }
+    if (entry->enabled != enabled) {
+        entry->enabled = enabled;
+        is_pending_reload.store(true);
+    }
+    return true;
 }
 
 void CheatEngine::FrameCallback(std::chrono::nanoseconds ns_late) {
     if (is_pending_reload.exchange(false)) {
+        std::scoped_lock lock{cheats_mutex};
         vm.LoadProgram(cheats);
     }
 

src/core/memory/cheat_engine.h

@@ -9,6 +9,7 @@
 #include <atomic>
 #include <chrono>
 #include <memory>
+#include <mutex>
 #include <vector>
 #include "common/common_types.h"
 #include "core/memory/dmnt_cheat_types.h"
@@ -41,6 +42,7 @@ public:
     void ResumeProcess() override;
     void DebugLog(u8 id, u64 value) override;
     void CommandLog(std::string_view data) override;
+    [[nodiscard]] bool IsCommandLogEnabled() const override;
 
 private:
     bool IsAddressInRange(VAddr address) const;
@@ -81,6 +83,8 @@ public:
     void SetMainMemoryParameters(VAddr main_region_begin, u64 main_region_size);
 
     void Reload(std::vector<CheatEntry> reload_cheats);
+    [[nodiscard]] std::vector<RuntimeCheatInfo> GetCheats() const;
+    bool SetCheatEnabled(u32 cheat_id, bool enabled);
 
 private:
     void FrameCallback(std::chrono::nanoseconds ns_late);
@@ -89,6 +93,7 @@ private:
     CheatProcessMetadata metadata;
 
     std::vector<CheatEntry> cheats;
+    mutable std::mutex cheats_mutex;
     std::atomic_bool is_pending_reload{false};
 
     std::shared_ptr<Core::Timing::EventType> event;

src/core/memory/dmnt_cheat_types.h

@@ -1,8 +1,14 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
+#include <string>
+#include <vector>
+
 #include "common/common_types.h"
 
 namespace Core::Memory {
@@ -24,14 +30,21 @@ struct CheatProcessMetadata {
 
 struct CheatDefinition {
     std::array<char, 0x40> readable_name{};
-    u32 num_opcodes{};
-    std::array<u32, 0x100> opcodes{};
+    std::vector<u32> opcodes;
 };
 
 struct CheatEntry {
     bool enabled{};
+    bool is_master{};
     u32 cheat_id{};
     CheatDefinition definition{};
 };
 
+struct RuntimeCheatInfo {
+    u32 id{};
+    std::string name;
+    bool enabled{};
+    bool is_master{};
+};
+
 } // namespace Core::Memory

src/core/memory/dmnt_cheat_vm.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -233,7 +236,7 @@ bool DmntCheatVm::DecodeNextOpcode(CheatVmOpcode& out) {
 
     // Helper function for getting instruction dwords.
     const auto GetNextDword = [&] {
-        if (instruction_ptr >= num_opcodes) {
+        if (instruction_ptr >= program.size()) {
             valid = false;
             return static_cast<u32>(0);
         }
@@ -709,20 +712,20 @@ void DmntCheatVm::ResetState() {
 }
 
 bool DmntCheatVm::LoadProgram(const std::vector<CheatEntry>& entries) {
-    // Reset opcode count.
-    num_opcodes = 0;
+    program.clear();
 
-    for (std::size_t i = 0; i < entries.size(); i++) {
-        if (entries[i].enabled) {
-            // Bounds check.
-            if (entries[i].definition.num_opcodes + num_opcodes > MaximumProgramOpcodeCount) {
-                num_opcodes = 0;
-                return false;
-            }
+    std::size_t program_size{};
+    for (const auto& entry : entries) {
+        if (entry.enabled || entry.is_master) {
+            program_size += entry.definition.opcodes.size();
+        }
+    }
+    program.reserve(program_size);
 
-            for (std::size_t n = 0; n < entries[i].definition.num_opcodes; n++) {
-                program[num_opcodes++] = entries[i].definition.opcodes[n];
-            }
+    for (const auto& entry : entries) {
+        if (entry.enabled || entry.is_master) {
+            program.insert(program.end(), entry.definition.opcodes.begin(),
+                           entry.definition.opcodes.end());
         }
     }
 
@@ -735,27 +738,35 @@ void DmntCheatVm::Execute(const CheatProcessMetadata& metadata) {
     // Get Keys down.
     u64 kDown = callbacks->HidKeysDown();
 
-    callbacks->CommandLog("Started VM execution.");
-    callbacks->CommandLog(fmt::format("Main NSO:  {:012X}", metadata.main_nso_extents.base));
-    callbacks->CommandLog(fmt::format("Heap:      {:012X}", metadata.main_nso_extents.base));
-    callbacks->CommandLog(fmt::format("Keys Down: {:08X}", static_cast<u32>(kDown & 0x0FFFFFFF)));
+    const bool command_log_enabled = callbacks->IsCommandLogEnabled();
+    if (command_log_enabled) {
+        callbacks->CommandLog("Started VM execution.");
+        callbacks->CommandLog(fmt::format("Main NSO:  {:012X}", metadata.main_nso_extents.base));
+        callbacks->CommandLog(fmt::format("Heap:      {:012X}", metadata.main_nso_extents.base));
+        callbacks->CommandLog(
+            fmt::format("Keys Down: {:08X}", static_cast<u32>(kDown & 0x0FFFFFFF)));
+    }
 
     // Clear VM state.
     ResetState();
 
     // Loop until program finishes.
     while (DecodeNextOpcode(cur_opcode)) {
-        callbacks->CommandLog(
-            fmt::format("Instruction Ptr: {:04X}", static_cast<u32>(instruction_ptr)));
+        if (command_log_enabled) {
+            callbacks->CommandLog(
+                fmt::format("Instruction Ptr: {:04X}", static_cast<u32>(instruction_ptr)));
 
-        for (std::size_t i = 0; i < NumRegisters; i++) {
-            callbacks->CommandLog(fmt::format("Registers[{:02X}]: {:016X}", i, registers[i]));
-        }
+            for (std::size_t i = 0; i < NumRegisters; i++) {
+                callbacks->CommandLog(fmt::format("Registers[{:02X}]: {:016X}", i,
+                                                  registers[i]));
+            }
 
-        for (std::size_t i = 0; i < NumRegisters; i++) {
-            callbacks->CommandLog(fmt::format("SavedRegs[{:02X}]: {:016X}", i, saved_values[i]));
+            for (std::size_t i = 0; i < NumRegisters; i++) {
+                callbacks->CommandLog(fmt::format("SavedRegs[{:02X}]: {:016X}", i,
+                                                  saved_values[i]));
+            }
+            LogOpcode(cur_opcode);
         }
-        LogOpcode(cur_opcode);
 
         // Increment conditional depth, if relevant.
         if (cur_opcode.begin_conditional_block) {

src/core/memory/dmnt_cheat_vm.h

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2019 yuzu Emulator Project
@@ -281,9 +281,9 @@ public:
 
         virtual void DebugLog(u8 id, u64 value) = 0;
         virtual void CommandLog(std::string_view data) = 0;
+        [[nodiscard]] virtual bool IsCommandLogEnabled() const = 0;
     };
 
-    static constexpr std::size_t MaximumProgramOpcodeCount = 0x400;
     static constexpr std::size_t NumRegisters = 0x10;
     static constexpr std::size_t NumReadableStaticRegisters = 0x80;
     static constexpr std::size_t NumWritableStaticRegisters = 0x80;
@@ -294,7 +294,7 @@ public:
     ~DmntCheatVm();
 
     std::size_t GetProgramSize() const {
-        return this->num_opcodes;
+        return program.size();
     }
 
     bool LoadProgram(const std::vector<CheatEntry>& cheats);
@@ -303,11 +303,10 @@ public:
 private:
     std::unique_ptr<Callbacks> callbacks;
 
-    std::size_t num_opcodes = 0;
     std::size_t instruction_ptr = 0;
     std::size_t condition_depth = 0;
     bool decode_success = false;
-    std::array<u32, MaximumProgramOpcodeCount> program{};
+    std::vector<u32> program;
     std::array<u64, NumRegisters> registers{};
     std::array<u64, NumRegisters> saved_values{};
     std::array<u64, NumStaticRegisters> static_registers{};