HLE: Refactor ReplaceFunctionIfPossible

Source/Core/Core/HLE/HLE.cpp

@@ -200,6 +200,23 @@ HookFlag GetHookFlagsByIndex(u32 index)
   return os_patches[index].flags;
 }
 
+TryReplaceFunctionResult TryReplaceFunction(u32 address)
+{
+  const u32 hook_index = GetHookByFunctionAddress(address);
+  if (hook_index == 0)
+    return {};
+
+  const HookType type = GetHookTypeByIndex(hook_index);
+  if (type != HookType::Start && type != HookType::Replace)
+    return {};
+
+  const HookFlag flags = GetHookFlagsByIndex(hook_index);
+  if (!IsEnabled(flags))
+    return {};
+
+  return {type, hook_index};
+}
+
 bool IsEnabled(HookFlag flag)
 {
   return flag != HLE::HookFlag::Debug || Config::Get(Config::MAIN_ENABLE_DEBUGGING) ||

Source/Core/Core/HLE/HLE.h

@@ -19,9 +19,9 @@ using HookFunction = void (*)(const Core::CPUThreadGuard&);
 
 enum class HookType
 {
+  None,     // Do not hook the function
   Start,    // Hook the beginning of the function and execute the function afterwards
   Replace,  // Replace the function with the HLE version
-  None,     // Do not hook the function
 };
 
 enum class HookFlag
@@ -39,6 +39,14 @@ struct Hook
   HookFlag flags;
 };
 
+struct TryReplaceFunctionResult
+{
+  HookType type = HookType::None;
+  u32 hook_index = 0;
+
+  explicit operator bool() const { return type != HookType::None; }
+};
+
 void PatchFixedFunctions(Core::System& system);
 void PatchFunctions(Core::System& system);
 void Clear();
@@ -59,32 +67,8 @@ HookFlag GetHookFlagsByIndex(u32 index);
 
 bool IsEnabled(HookFlag flag);
 
-// Performs the backend-independent preliminary checking before calling a
-// FunctionObject to do the actual replacing. Typically, this callback will
-// be in the backend itself, containing the backend-specific portions
-// required in replacing a function.
-//
-// fn may be any object that satisfies the FunctionObject concept in the C++
-// standard library. That is, any lambda, object with an overloaded function
-// call operator, or regular function pointer.
-//
-// fn must return a bool indicating whether or not function replacing occurred.
-// fn must also accept a parameter list of the form: fn(u32 function, HLE::HookType type).
-template <typename FunctionObject>
-bool ReplaceFunctionIfPossible(u32 address, FunctionObject fn)
-{
-  const u32 hook_index = GetHookByFunctionAddress(address);
-  if (hook_index == 0)
-    return false;
+// Performs the backend-independent preliminary checking for whether a function
+// can be HLEd. If it can be, the information needed for HLEing it is returned.
+TryReplaceFunctionResult TryReplaceFunction(u32 address);
 
-  const HookType type = GetHookTypeByIndex(hook_index);
-  if (type != HookType::Start && type != HookType::Replace)
-    return false;
-
-  const HookFlag flags = GetHookFlagsByIndex(hook_index);
-  if (!IsEnabled(flags))
-    return false;
-
-  return fn(hook_index, type);
-}
 }  // namespace HLE

Source/Core/Core/PowerPC/CachedInterpreter/CachedInterpreter.cpp

@@ -269,17 +269,19 @@ bool CachedInterpreter::CheckIdle(CachedInterpreter& cached_interpreter, u32 idl
 
 bool CachedInterpreter::HandleFunctionHooking(u32 address)
 {
-  return HLE::ReplaceFunctionIfPossible(address, [&](u32 hook_index, HLE::HookType type) {
-    m_code.emplace_back(WritePC, address);
-    m_code.emplace_back(Interpreter::HLEFunction, hook_index);
+  const auto result = HLE::TryReplaceFunction(address);
+  if (!result)
+    return false;
 
-    if (type != HLE::HookType::Replace)
-      return false;
+  m_code.emplace_back(WritePC, address);
+  m_code.emplace_back(Interpreter::HLEFunction, result.hook_index);
 
-    m_code.emplace_back(EndBlock, js.downcountAmount);
-    m_code.emplace_back();
-    return true;
-  });
+  if (result.type != HLE::HookType::Replace)
+    return false;
+
+  m_code.emplace_back(EndBlock, js.downcountAmount);
+  m_code.emplace_back();
+  return true;
 }
 
 void CachedInterpreter::Jit(u32 address)

Source/Core/Core/PowerPC/Interpreter/Interpreter.cpp

@@ -106,10 +106,13 @@ void Interpreter::Trace(const UGeckoInstruction& inst)
 
 bool Interpreter::HandleFunctionHooking(u32 address)
 {
-  return HLE::ReplaceFunctionIfPossible(address, [this](u32 hook_index, HLE::HookType type) {
-    HLEFunction(*this, hook_index);
-    return type != HLE::HookType::Start;
-  });
+  const auto result = HLE::TryReplaceFunction(address);
+  if (!result)
+    return false;
+
+  HLEFunction(*this, result.hook_index);
+
+  return result.type != HLE::HookType::Start;
 }
 
 int Interpreter::SingleStepInner()

Source/Core/Core/PowerPC/Jit64/Jit.cpp

@@ -1238,17 +1238,19 @@ void Jit64::IntializeSpeculativeConstants()
 
 bool Jit64::HandleFunctionHooking(u32 address)
 {
-  return HLE::ReplaceFunctionIfPossible(address, [&](u32 hook_index, HLE::HookType type) {
-    HLEFunction(hook_index);
+  const auto result = HLE::TryReplaceFunction(address);
+  if (!result)
+    return false;
 
-    if (type != HLE::HookType::Replace)
-      return false;
+  HLEFunction(result.hook_index);
 
-    MOV(32, R(RSCRATCH), PPCSTATE(npc));
-    js.downcountAmount += js.st.numCycles;
-    WriteExitDestInRSCRATCH();
-    return true;
-  });
+  if (result.type != HLE::HookType::Replace)
+    return false;
+
+  MOV(32, R(RSCRATCH), PPCSTATE(npc));
+  js.downcountAmount += js.st.numCycles;
+  WriteExitDestInRSCRATCH();
+  return true;
 }
 
 void LogGeneratedX86(size_t size, const PPCAnalyst::CodeBuffer& code_buffer, const u8* normalEntry,

Source/Core/Core/PowerPC/JitArm64/Jit.cpp

@@ -696,17 +696,19 @@ void JitArm64::WriteConditionalExceptionExit(int exception, ARM64Reg temp_gpr, A
 
 bool JitArm64::HandleFunctionHooking(u32 address)
 {
-  return HLE::ReplaceFunctionIfPossible(address, [&](u32 hook_index, HLE::HookType type) {
-    HLEFunction(hook_index);
+  const auto result = HLE::TryReplaceFunction(address);
+  if (!result)
+    return false;
 
-    if (type != HLE::HookType::Replace)
-      return false;
+  HLEFunction(result.hook_index);
 
-    LDR(IndexType::Unsigned, DISPATCHER_PC, PPC_REG, PPCSTATE_OFF(npc));
-    js.downcountAmount += js.st.numCycles;
-    WriteExit(DISPATCHER_PC);
-    return true;
-  });
+  if (result.type != HLE::HookType::Replace)
+    return false;
+
+  LDR(IndexType::Unsigned, DISPATCHER_PC, PPC_REG, PPCSTATE_OFF(npc));
+  js.downcountAmount += js.st.numCycles;
+  WriteExit(DISPATCHER_PC);
+  return true;
 }
 
 void JitArm64::DumpCode(const u8* start, const u8* end)