core/core: Replace includes with forward declarations where applicable

The follow-up to e2457418dae19b889b2ad85255bb95d4cd0e4bff, which
replaces most of the includes in the core header with forward declarations.

This makes it so that if any of the headers the core header was
previously including change, then no one will need to rebuild the bulk
of the core, due to core.h being quite a prevalent inclusion.

This should make turnaround for changes much faster for developers.

18 files changed, 85 insertions, 43 deletions

diff --git a/src/core/arm/dynarmic/arm_dynarmic.cpp b/src/core/arm/dynarmic/arm_dynarmic.cpp
index f96e08212..de44ccebd 100644
--- a/src/core/arm/dynarmic/arm_dynarmic.cpp
+++ b/src/core/arm/dynarmic/arm_dynarmic.cpp
@@ -9,6 +9,7 @@
 #include "common/logging/log.h"
 #include "core/arm/dynarmic/arm_dynarmic.h"
 #include "core/core.h"
+#include "core/core_cpu.h"
 #include "core/core_timing.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/svc.h"
diff --git a/src/core/core.cpp b/src/core/core.cpp
index 75c259068..2cfae18df 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -2,24 +2,35 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <array>
+#include <map>
 #include <memory>
+#include <thread>
 #include <utility>
+
 #include "common/logging/log.h"
 #include "common/string_util.h"
+#include "core/arm/exclusive_monitor.h"
 #include "core/core.h"
+#include "core/core_cpu.h"
 #include "core/core_timing.h"
 #include "core/gdbstub/gdbstub.h"
 #include "core/hle/kernel/client_port.h"
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/process.h"
+#include "core/hle/kernel/scheduler.h"
 #include "core/hle/kernel/thread.h"
 #include "core/hle/service/service.h"
 #include "core/hle/service/sm/controller.h"
 #include "core/hle/service/sm/sm.h"
 #include "core/loader/loader.h"
+#include "core/perf_stats.h"
 #include "core/settings.h"
+#include "core/telemetry_session.h"
 #include "file_sys/vfs_concat.h"
 #include "file_sys/vfs_real.h"
+#include "video_core/debug_utils/debug_utils.h"
+#include "video_core/gpu.h"
 #include "video_core/renderer_base.h"
 #include "video_core/video_core.h"
 
@@ -258,7 +269,7 @@ struct System::Impl {
         }
     }
 
-    PerfStats::Results GetAndResetPerfStats() {
+    PerfStatsResults GetAndResetPerfStats() {
         return perf_stats.GetAndResetStats(CoreTiming::GetGlobalTimeUs());
     }
 
@@ -326,7 +337,7 @@ void System::PrepareReschedule() {
     CurrentCpuCore().PrepareReschedule();
 }
 
-PerfStats::Results System::GetAndResetPerfStats() {
+PerfStatsResults System::GetAndResetPerfStats() {
     return impl->GetAndResetPerfStats();
 }
 
@@ -433,11 +444,11 @@ std::shared_ptr<Tegra::DebugContext> System::GetGPUDebugContext() const {
     return impl->debug_context;
 }
 
-void System::SetFilesystem(FileSys::VirtualFilesystem vfs) {
+void System::SetFilesystem(std::shared_ptr<FileSys::VfsFilesystem> vfs) {
     impl->virtual_filesystem = std::move(vfs);
 }
 
-FileSys::VirtualFilesystem System::GetFilesystem() const {
+std::shared_ptr<FileSys::VfsFilesystem> System::GetFilesystem() const {
     return impl->virtual_filesystem;
 }
 
diff --git a/src/core/core.h b/src/core/core.h
index 984e8f94c..eee1fecc1 100644
--- a/src/core/core.h
+++ b/src/core/core.h
@@ -4,41 +4,55 @@
 
 #pragma once
 
-#include <array>
-#include <map>
+#include <cstddef>
 #include <memory>
 #include <string>
-#include <thread>
+
 #include "common/common_types.h"
-#include "core/arm/exclusive_monitor.h"
-#include "core/core_cpu.h"
-#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/object.h"
-#include "core/hle/kernel/scheduler.h"
-#include "core/loader/loader.h"
-#include "core/memory.h"
-#include "core/perf_stats.h"
-#include "core/telemetry_session.h"
-#include "file_sys/vfs_real.h"
-#include "hle/service/filesystem/filesystem.h"
-#include "video_core/debug_utils/debug_utils.h"
-#include "video_core/gpu.h"
 
 namespace Core::Frontend {
 class EmuWindow;
-}
+} // namespace Core::Frontend
+
+namespace FileSys {
+class VfsFilesystem;
+} // namespace FileSys
+
+namespace Kernel {
+class KernelCore;
+class Process;
+class Scheduler;
+} // namespace Kernel
+
+namespace Loader {
+class AppLoader;
+enum class ResultStatus : u16;
+} // namespace Loader
 
 namespace Service::SM {
 class ServiceManager;
-}
+} // namespace Service::SM
+
+namespace Tegra {
+class DebugContext;
+class GPU;
+} // namespace Tegra
 
 namespace VideoCore {
 class RendererBase;
-}
+} // namespace VideoCore
 
 namespace Core {
 
 class ARM_Interface;
+class Cpu;
+class ExclusiveMonitor;
+class FrameLimiter;
+class PerfStats;
+class TelemetrySession;
+
+struct PerfStatsResults;
 
 class System {
 public:
@@ -125,7 +139,7 @@ public:
     void PrepareReschedule();
 
     /// Gets and resets core performance statistics
-    PerfStats::Results GetAndResetPerfStats();
+    PerfStatsResults GetAndResetPerfStats();
 
     /// Gets an ARM interface to the CPU core that is currently running
     ARM_Interface& CurrentArmInterface();
@@ -197,9 +211,9 @@ public:
 
     std::shared_ptr<Tegra::DebugContext> GetGPUDebugContext() const;
 
-    void SetFilesystem(FileSys::VirtualFilesystem vfs);
+    void SetFilesystem(std::shared_ptr<FileSys::VfsFilesystem> vfs);
 
-    FileSys::VirtualFilesystem GetFilesystem() const;
+    std::shared_ptr<FileSys::VfsFilesystem> GetFilesystem() const;
 
 private:
     System();
diff --git a/src/core/file_sys/savedata_factory.cpp b/src/core/file_sys/savedata_factory.cpp
index 034d3a78f..952bd74b3 100644
--- a/src/core/file_sys/savedata_factory.cpp
+++ b/src/core/file_sys/savedata_factory.cpp
@@ -7,6 +7,7 @@
 #include "common/logging/log.h"
 #include "core/core.h"
 #include "core/file_sys/savedata_factory.h"
+#include "core/file_sys/vfs.h"
 #include "core/hle/kernel/process.h"
 
 namespace FileSys {
diff --git a/src/core/file_sys/savedata_factory.h b/src/core/file_sys/savedata_factory.h
index 368b36017..c6f9549f0 100644
--- a/src/core/file_sys/savedata_factory.h
+++ b/src/core/file_sys/savedata_factory.h
@@ -8,6 +8,7 @@
 #include <string>
 #include "common/common_types.h"
 #include "common/swap.h"
+#include "core/file_sys/vfs.h"
 #include "core/hle/result.h"
 
 namespace FileSys {
diff --git a/src/core/hle/kernel/address_arbiter.cpp b/src/core/hle/kernel/address_arbiter.cpp
index 03a954a9f..6657accd5 100644
--- a/src/core/hle/kernel/address_arbiter.cpp
+++ b/src/core/hle/kernel/address_arbiter.cpp
@@ -8,9 +8,11 @@
 #include "common/assert.h"
 #include "common/common_types.h"
 #include "core/core.h"
+#include "core/core_cpu.h"
 #include "core/hle/kernel/errors.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/process.h"
+#include "core/hle/kernel/scheduler.h"
 #include "core/hle/kernel/thread.h"
 #include "core/hle/result.h"
 #include "core/memory.h"
diff --git a/src/core/hle/kernel/hle_ipc.cpp b/src/core/hle/kernel/hle_ipc.cpp
index db7aef766..7264be906 100644
--- a/src/core/hle/kernel/hle_ipc.cpp
+++ b/src/core/hle/kernel/hle_ipc.cpp
@@ -18,6 +18,7 @@
 #include "core/hle/kernel/event.h"
 #include "core/hle/kernel/handle_table.h"
 #include "core/hle/kernel/hle_ipc.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/server_session.h"
diff --git a/src/core/hle/kernel/server_session.cpp b/src/core/hle/kernel/server_session.cpp
index 90c9a5aff..aba0cab96 100644
--- a/src/core/hle/kernel/server_session.cpp
+++ b/src/core/hle/kernel/server_session.cpp
@@ -13,6 +13,7 @@
 #include "core/hle/kernel/client_session.h"
 #include "core/hle/kernel/handle_table.h"
 #include "core/hle/kernel/hle_ipc.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/server_session.h"
 #include "core/hle/kernel/session.h"
@@ -104,11 +105,10 @@ ResultCode ServerSession::HandleSyncRequest(SharedPtr<Thread> thread) {
     // The ServerSession received a sync request, this means that there's new data available
     // from its ClientSession, so wake up any threads that may be waiting on a svcReplyAndReceive or
     // similar.
-
-    auto& handle_table = Core::System::GetInstance().Kernel().HandleTable();
     Kernel::HLERequestContext context(this);
     u32* cmd_buf = (u32*)Memory::GetPointer(thread->GetTLSAddress());
-    context.PopulateFromIncomingCommandBuffer(cmd_buf, *Core::CurrentProcess(), handle_table);
+    context.PopulateFromIncomingCommandBuffer(cmd_buf, *Core::CurrentProcess(),
+                                              kernel.HandleTable());
 
     ResultCode result = RESULT_SUCCESS;
     // If the session has been converted to a domain, handle the domain request
diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index 099d1053f..5da71cff0 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -12,16 +12,20 @@
 #include "common/logging/log.h"
 #include "common/microprofile.h"
 #include "common/string_util.h"
+#include "core/arm/exclusive_monitor.h"
 #include "core/core.h"
+#include "core/core_cpu.h"
 #include "core/core_timing.h"
 #include "core/hle/kernel/address_arbiter.h"
 #include "core/hle/kernel/client_port.h"
 #include "core/hle/kernel/client_session.h"
 #include "core/hle/kernel/event.h"
 #include "core/hle/kernel/handle_table.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/mutex.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
+#include "core/hle/kernel/scheduler.h"
 #include "core/hle/kernel/shared_memory.h"
 #include "core/hle/kernel/svc.h"
 #include "core/hle/kernel/svc_wrap.h"
diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp
index 520ea0853..3d10d9af2 100644
--- a/src/core/hle/kernel/thread.cpp
+++ b/src/core/hle/kernel/thread.cpp
@@ -16,6 +16,7 @@
 #include "common/thread_queue_list.h"
 #include "core/arm/arm_interface.h"
 #include "core/core.h"
+#include "core/core_cpu.h"
 #include "core/core_timing.h"
 #include "core/core_timing_util.h"
 #include "core/hle/kernel/errors.h"
@@ -23,8 +24,8 @@
 #include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/process.h"
+#include "core/hle/kernel/scheduler.h"
 #include "core/hle/kernel/thread.h"
-#include "core/hle/lock.h"
 #include "core/hle/result.h"
 #include "core/memory.h"
 
diff --git a/src/core/hle/service/filesystem/filesystem.h b/src/core/hle/service/filesystem/filesystem.h
index d88a66825..9ba0e2eab 100644
--- a/src/core/hle/service/filesystem/filesystem.h
+++ b/src/core/hle/service/filesystem/filesystem.h
@@ -7,6 +7,7 @@
 #include <memory>
 #include "common/common_types.h"
 #include "core/file_sys/directory.h"
+#include "core/file_sys/vfs.h"
 #include "core/hle/result.h"
 
 namespace FileSys {
diff --git a/src/core/loader/deconstructed_rom_directory.cpp b/src/core/loader/deconstructed_rom_directory.cpp
index a53fa6e00..921b899e2 100644
--- a/src/core/loader/deconstructed_rom_directory.cpp
+++ b/src/core/loader/deconstructed_rom_directory.cpp
@@ -11,6 +11,7 @@
 #include "core/file_sys/control_metadata.h"
 #include "core/file_sys/romfs_factory.h"
 #include "core/gdbstub/gdbstub.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
 #include "core/hle/service/filesystem/filesystem.h"
diff --git a/src/core/loader/elf.cpp b/src/core/loader/elf.cpp
index 3702a8478..120e1e133 100644
--- a/src/core/loader/elf.cpp
+++ b/src/core/loader/elf.cpp
@@ -10,6 +10,7 @@
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "core/core.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
 #include "core/loader/elf.h"
diff --git a/src/core/loader/nro.cpp b/src/core/loader/nro.cpp
index 00205d1d2..77026b850 100644
--- a/src/core/loader/nro.cpp
+++ b/src/core/loader/nro.cpp
@@ -14,6 +14,7 @@
 #include "core/file_sys/control_metadata.h"
 #include "core/file_sys/vfs_offset.h"
 #include "core/gdbstub/gdbstub.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
 #include "core/loader/nro.h"
diff --git a/src/core/loader/nso.cpp b/src/core/loader/nso.cpp
index 0c992d662..082a95d40 100644
--- a/src/core/loader/nso.cpp
+++ b/src/core/loader/nso.cpp
@@ -11,6 +11,7 @@
 #include "common/swap.h"
 #include "core/core.h"
 #include "core/gdbstub/gdbstub.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/resource_limit.h"
 #include "core/loader/nso.h"
diff --git a/src/core/perf_stats.cpp b/src/core/perf_stats.cpp
index 93d23de21..7d95816fe 100644
--- a/src/core/perf_stats.cpp
+++ b/src/core/perf_stats.cpp
@@ -40,7 +40,7 @@ void PerfStats::EndGameFrame() {
     game_frames += 1;
 }
 
-PerfStats::Results PerfStats::GetAndResetStats(microseconds current_system_time_us) {
+PerfStatsResults PerfStats::GetAndResetStats(microseconds current_system_time_us) {
     std::lock_guard<std::mutex> lock(object_mutex);
 
     const auto now = Clock::now();
@@ -49,7 +49,7 @@ PerfStats::Results PerfStats::GetAndResetStats(microseconds current_system_time_
 
     const auto system_us_per_second = (current_system_time_us - reset_point_system_us) / interval;
 
-    Results results{};
+    PerfStatsResults results{};
     results.system_fps = static_cast<double>(system_frames) / interval;
     results.game_fps = static_cast<double>(game_frames) / interval;
     results.frametime = duration_cast<DoubleSecs>(accumulated_frametime).count() /
diff --git a/src/core/perf_stats.h b/src/core/perf_stats.h
index 6e4619701..222ac1a63 100644
--- a/src/core/perf_stats.h
+++ b/src/core/perf_stats.h
@@ -10,6 +10,17 @@
 
 namespace Core {
 
+struct PerfStatsResults {
+    /// System FPS (LCD VBlanks) in Hz
+    double system_fps;
+    /// Game FPS (GSP frame submissions) in Hz
+    double game_fps;
+    /// Walltime per system frame, in seconds, excluding any waits
+    double frametime;
+    /// Ratio of walltime / emulated time elapsed
+    double emulation_speed;
+};
+
 /**
  * Class to manage and query performance/timing statistics. All public functions of this class are
  * thread-safe unless stated otherwise.
@@ -18,22 +29,11 @@ class PerfStats {
 public:
     using Clock = std::chrono::high_resolution_clock;
 
-    struct Results {
-        /// System FPS (LCD VBlanks) in Hz
-        double system_fps;
-        /// Game FPS (GSP frame submissions) in Hz
-        double game_fps;
-        /// Walltime per system frame, in seconds, excluding any waits
-        double frametime;
-        /// Ratio of walltime / emulated time elapsed
-        double emulation_speed;
-    };
-
     void BeginSystemFrame();
     void EndSystemFrame();
     void EndGameFrame();
 
-    Results GetAndResetStats(std::chrono::microseconds current_system_time_us);
+    PerfStatsResults GetAndResetStats(std::chrono::microseconds current_system_time_us);
 
     /**
      * Gets the ratio between walltime and the emulated time of the previous system frame. This is
diff --git a/src/core/telemetry_session.cpp b/src/core/telemetry_session.cpp
index 827a1bbd0..65571b948 100644
--- a/src/core/telemetry_session.cpp
+++ b/src/core/telemetry_session.cpp
@@ -7,6 +7,7 @@
 #include "common/file_util.h"
 
 #include "core/core.h"
+#include "core/loader/loader.h"
 #include "core/settings.h"
 #include "core/telemetry_session.h"