Sprinkle const around where appropriate (melonDS-emu#1909)

* Sprinkle `const` around where appropriate

- This will make it easier to use `NDS` objects in `const` contexts (e.g. `const` parameters or methods)

* Remove the `const` qualifier on `DSi_DSP::DSPRead16`

- MMIO reads can be non-pure, so this may not be `const` in the future

src/AREngine.cpp

@@ -40,16 +40,16 @@ AREngine::AREngine(melonDS::NDS& nds) : NDS(nds)
     case ((x)+0x08): case ((x)+0x09): case ((x)+0x0A): case ((x)+0x0B): \
     case ((x)+0x0C): case ((x)+0x0D): case ((x)+0x0E): case ((x)+0x0F)
 
-void AREngine::RunCheat(ARCode& arcode)
+void AREngine::RunCheat(const ARCode& arcode)
 {
-    u32* code = &arcode.Code[0];
+    const u32* code = &arcode.Code[0];
 
     u32 offset = 0;
     u32 datareg = 0;
     u32 cond = 1;
     u32 condstack = 0;
 
-    u32* loopstart = code;
+    const u32* loopstart = code;
     u32 loopcount = 0;
     u32 loopcond = 1;
     u32 loopcondstack = 0;

src/AREngine.h

@@ -33,7 +33,7 @@ class AREngine
     void SetCodeFile(ARCodeFile* file) { CodeFile = file; }
 
     void RunCheats();
-    void RunCheat(ARCode& arcode);
+    void RunCheat(const ARCode& arcode);
 private:
     melonDS::NDS& NDS;
     ARCodeFile* CodeFile; // AR code file - frontend is responsible for managing this

src/ARM.h

@@ -80,7 +80,7 @@ class ARM
     virtual void ExecuteJIT() = 0;
 #endif
 
-    bool CheckCondition(u32 code)
+    bool CheckCondition(u32 code) const
     {
         if (code == 0xE) return true;
         if (ConditionTable[code] & (1 << (CPSR>>28))) return true;
@@ -109,7 +109,7 @@ class ARM
         if (v) CPSR |= 0x10000000;
     }
 
-    inline bool ModeIs(u32 mode)
+    inline bool ModeIs(u32 mode) const
     {
         u32 cm = CPSR & 0x1f;
         mode &= 0x1f;
@@ -315,7 +315,7 @@ class ARMv5 : public ARM
     void ICacheInvalidateAll();
 
     void CP15Write(u32 id, u32 val);
-    u32 CP15Read(u32 id);
+    u32 CP15Read(u32 id) const;
 
     u32 CP15Control;
 

src/ARMJIT_A64/ARMJIT_Compiler.h

@@ -114,7 +114,7 @@ class Compiler : public Arm64Gen::ARM64XEmitter
 
     bool CanCompile(bool thumb, u16 kind);
 
-    bool FlagsNZNeeded()
+    bool FlagsNZNeeded() const
     {
         return CurInstr.SetFlags & 0xC;
     }
@@ -234,7 +234,7 @@ class Compiler : public Arm64Gen::ARM64XEmitter
         return (u8*)entry - GetRXBase();
     }
 
-    bool IsJITFault(u8* pc);
+    bool IsJITFault(const u8* pc);
     u8* RewriteMemAccess(u8* pc);
 
     void SwapCodeRegion()

src/ARMJIT_A64/ARMJIT_LoadStore.cpp

@@ -28,7 +28,7 @@ using namespace Arm64Gen;
 namespace melonDS
 {
 
-bool Compiler::IsJITFault(u8* pc)
+bool Compiler::IsJITFault(const u8* pc)
 {
     return (u64)pc >= (u64)GetRXBase() && (u64)pc - (u64)GetRXBase() < (JitMemMainSize + JitMemSecondarySize);
 }

src/ARMJIT_Internal.h

@@ -85,7 +85,7 @@ typedef void (*InterpreterFunc)(ARM* cpu);
 extern InterpreterFunc InterpretARM[];
 extern InterpreterFunc InterpretTHUMB[];
 
-inline bool PageContainsCode(AddressRange* range)
+inline bool PageContainsCode(const AddressRange* range)
 {
     for (int i = 0; i < 8; i++)
     {

src/ARMJIT_RegisterCache.h

@@ -99,7 +99,7 @@ class RegisterCache
         LiteralsLoaded &= ~(1 << reg);
     }
 
-    bool IsLiteral(int reg)
+    bool IsLiteral(int reg) const
     {
         return LiteralsLoaded & (1 << reg);
     }

src/ARMJIT_x64/ARMJIT_Compiler.cpp

@@ -651,7 +651,7 @@ const Compiler::CompileFunc T_Comp[ARMInstrInfo::tk_Count] = {
 };
 #undef F
 
-bool Compiler::CanCompile(bool thumb, u16 kind)
+bool Compiler::CanCompile(bool thumb, u16 kind) const
 {
     return (thumb ? T_Comp[kind] : A_Comp[kind]) != NULL;
 }
@@ -667,7 +667,7 @@ void Compiler::Reset()
     LoadStorePatches.clear();
 }
 
-bool Compiler::IsJITFault(u8* addr)
+bool Compiler::IsJITFault(const u8* addr)
 {
     return (u64)addr >= (u64)ResetStart && (u64)addr < (u64)ResetStart + CodeMemSize;
 }

src/ARMJIT_x64/ARMJIT_Compiler.h

@@ -92,7 +92,7 @@ class Compiler : public Gen::XEmitter
     void LoadReg(int reg, Gen::X64Reg nativeReg);
     void SaveReg(int reg, Gen::X64Reg nativeReg);
 
-    bool CanCompile(bool thumb, u16 kind);
+    bool CanCompile(bool thumb, u16 kind) const;
 
     typedef void (Compiler::*CompileFunc)();
 
@@ -234,7 +234,7 @@ class Compiler : public Gen::XEmitter
         SetCodePtr(FarCode);
     }
 
-    bool IsJITFault(u8* addr);
+    bool IsJITFault(const u8* addr);
 
     u8* RewriteMemAccess(u8* pc);
 

src/CP15.cpp

@@ -668,7 +668,7 @@ void ARMv5::CP15Write(u32 id, u32 val)
         Log(LogLevel::Debug, "unknown CP15 write op %03X %08X\n", id, val);
 }
 
-u32 ARMv5::CP15Read(u32 id)
+u32 ARMv5::CP15Read(u32 id) const
 {
     //printf("CP15 read op %03X %08X\n", id, NDS::ARM9->R[15]);
 

src/DSi.cpp

@@ -181,7 +181,7 @@ std::unique_ptr<NDSCart::CartCommon> DSi::EjectCart()
     return oldcart;
 }
 
-void DSi::CamInputFrame(int cam, u32* data, int width, int height, bool rgb)
+void DSi::CamInputFrame(int cam, const u32* data, int width, int height, bool rgb)
 {
     switch (cam)
     {
@@ -277,7 +277,7 @@ void DSi::SetCartInserted(bool inserted)
         SCFG_MC |= 1;
 }
 
-void DSi::DecryptModcryptArea(u32 offset, u32 size, u8* iv)
+void DSi::DecryptModcryptArea(u32 offset, u32 size, const u8* iv)
 {
     AES_ctx ctx;
     u8 key[16];
@@ -957,21 +957,21 @@ void DSi::StallNDMAs()
 }
 
 
-bool DSi::DMAsInMode(u32 cpu, u32 mode)
+bool DSi::DMAsInMode(u32 cpu, u32 mode) const
 {
     if (NDS::DMAsInMode(cpu, mode)) return true;
 
     return NDMAsInMode(cpu, NDMAModes[mode]);
 }
 
-bool DSi::DMAsRunning(u32 cpu)
+bool DSi::DMAsRunning(u32 cpu) const
 {
     if (NDS::DMAsRunning(cpu)) return true;
 
     return NDMAsRunning(cpu);
 }
 
-bool DSi::NDMAsInMode(u32 cpu, u32 mode)
+bool DSi::NDMAsInMode(u32 cpu, u32 mode) const
 {
     cpu <<= 2;
     if (NDMAs[cpu+0].IsInMode(mode)) return true;
@@ -981,7 +981,7 @@ bool DSi::NDMAsInMode(u32 cpu, u32 mode)
     return false;
 }
 
-bool DSi::NDMAsRunning(u32 cpu)
+bool DSi::NDMAsRunning(u32 cpu) const
 {
     cpu <<= 2;
     if (NDMAs[cpu+0].IsRunning()) return true;

src/DSi.h

@@ -87,8 +87,8 @@ class DSi final : public NDS
 
     void RunNDMAs(u32 cpu);
     void StallNDMAs();
-    bool NDMAsInMode(u32 cpu, u32 mode);
-    bool NDMAsRunning(u32 cpu);
+    bool NDMAsInMode(u32 cpu, u32 mode) const;
+    bool NDMAsRunning(u32 cpu) const;
     void CheckNDMAs(u32 cpu, u32 mode);
     void StopNDMAs(u32 cpu, u32 mode);
 
@@ -138,7 +138,7 @@ class DSi final : public NDS
     DSi& operator=(DSi&&) = delete;
     void SetNDSCart(std::unique_ptr<NDSCart::CartCommon>&& cart) override;
     std::unique_ptr<NDSCart::CartCommon> EjectCart() override;
-    bool NeedsDirectBoot() override
+    bool NeedsDirectBoot() const override
     {
         // for now, DSi mode requires original BIOS/NAND
         return false;
@@ -153,9 +153,9 @@ class DSi final : public NDS
     void SetSDCard(FATStorage&& sdcard) noexcept { SDMMC.SetSDCard(std::move(sdcard)); }
     void SetSDCard(std::optional<FATStorage>&& sdcard) noexcept { SDMMC.SetSDCard(std::move(sdcard)); }
 
-    void CamInputFrame(int cam, u32* data, int width, int height, bool rgb) override;
-    bool DMAsInMode(u32 cpu, u32 mode) override;
-    bool DMAsRunning(u32 cpu) override;
+    void CamInputFrame(int cam, const u32* data, int width, int height, bool rgb) override;
+    bool DMAsInMode(u32 cpu, u32 mode) const override;
+    bool DMAsRunning(u32 cpu) const override;
     void StopDMAs(u32 cpu, u32 mode) override;
     void CheckDMAs(u32 cpu, u32 mode) override;
     u16 SCFG_Clock7;
@@ -178,7 +178,7 @@ class DSi final : public NDS
     bool FullBIOSBoot;
     void Set_SCFG_Clock9(u16 val);
     void Set_SCFG_MC(u32 val);
-    void DecryptModcryptArea(u32 offset, u32 size, u8* iv);
+    void DecryptModcryptArea(u32 offset, u32 size, const u8* iv);
     void ApplyNewRAMSize(u32 size);
 };
 

src/DSi_AES.cpp

@@ -235,7 +235,7 @@ void DSi_AES::ProcessBlock_CTR()
 }
 
 
-u32 DSi_AES::ReadCnt()
+u32 DSi_AES::ReadCnt() const
 {
     u32 ret = Cnt;
 

src/DSi_AES.h

@@ -54,7 +54,7 @@ class DSi_AES
     void Reset();
     void DoSavestate(Savestate* file);
 
-    u32 ReadCnt();
+    u32 ReadCnt() const;
     void WriteCnt(u32 val);
     void WriteBlkCnt(u32 val);
 

src/DSi_Camera.cpp

@@ -438,7 +438,7 @@ void DSi_Camera::Stop()
     Platform::Camera_Stop(Num);
 }
 
-bool DSi_Camera::IsActivated()
+bool DSi_Camera::IsActivated() const
 {
     if (StandbyCnt & (1<<14)) return false; // standby
     if (!(MiscCnt & (1<<9))) return false; // data transfer not enabled
@@ -477,7 +477,7 @@ void DSi_Camera::StartTransfer()
     Platform::Camera_CaptureFrame(Num, FrameBuffer, 640, 480, true);
 }
 
-bool DSi_Camera::TransferDone()
+bool DSi_Camera::TransferDone() const
 {
     return TransferY >= FrameHeight;
 }
@@ -590,7 +590,7 @@ void DSi_Camera::Write(u8 val, bool last)
     else      DataPos++;
 }
 
-u16 DSi_Camera::I2C_ReadReg(u16 addr)
+u16 DSi_Camera::I2C_ReadReg(u16 addr) const
 {
     switch (addr)
     {
@@ -695,7 +695,7 @@ void DSi_Camera::I2C_WriteReg(u16 addr, u16 val)
 // TODO: not sure at all what is the accessible range
 // or if there is any overlap in the address range
 
-u8 DSi_Camera::MCU_Read(u16 addr)
+u8 DSi_Camera::MCU_Read(u16 addr) const
 {
     addr &= 0x7FFF;
 
@@ -724,7 +724,7 @@ void DSi_Camera::MCU_Write(u16 addr, u8 val)
 }
 
 
-void DSi_Camera::InputFrame(u32* data, int width, int height, bool rgb)
+void DSi_Camera::InputFrame(const u32* data, int width, int height, bool rgb)
 {
     // TODO: double-buffering?
 

src/DSi_Camera.h

@@ -38,10 +38,10 @@ class DSi_Camera : public DSi_I2CDevice
 
     void Reset() override;
     void Stop();
-    bool IsActivated();
+    bool IsActivated() const;
 
     void StartTransfer();
-    bool TransferDone();
+    bool TransferDone() const;
 
     // lengths in words
     int TransferScanline(u32* buffer, int maxlen);
@@ -50,7 +50,7 @@ class DSi_Camera : public DSi_I2CDevice
     u8 Read(bool last) override;
     void Write(u8 val, bool last) override;
 
-    void InputFrame(u32* data, int width, int height, bool rgb);
+    void InputFrame(const u32* data, int width, int height, bool rgb);
 
     u32 Num;
 
@@ -59,7 +59,7 @@ class DSi_Camera : public DSi_I2CDevice
     u32 RegAddr;
     u16 RegData;
 
-    u16 I2C_ReadReg(u16 addr);
+    u16 I2C_ReadReg(u16 addr) const;
     void I2C_WriteReg(u16 addr, u16 val);
 
     u16 PLLDiv;
@@ -72,7 +72,7 @@ class DSi_Camera : public DSi_I2CDevice
     u16 MCUAddr;
     u8 MCURegs[0x8000];
 
-    u8 MCU_Read(u16 addr);
+    u8 MCU_Read(u16 addr) const;
     void MCU_Write(u16 addr, u8 val);
 
     u16 FrameWidth, FrameHeight;
@@ -91,7 +91,9 @@ class DSi_CamModule
     void Stop();
     void DoSavestate(Savestate* file);
 
+    const DSi_Camera* GetOuterCamera() const { return Camera0; }
     DSi_Camera* GetOuterCamera() { return Camera0; }
+    const DSi_Camera* GetInnerCamera() const { return Camera1; }
     DSi_Camera* GetInnerCamera() { return Camera1; }
 
     void IRQ(u32 param);

src/DSi_DSP.cpp

@@ -34,7 +34,7 @@ const u32 DSi_DSP::DataMemoryOffset = 0x20000; // from Teakra memory_interface.h
 // NOTE: ^ IS IN DSP WORDS, NOT IN BYTES!
 
 
-u16 DSi_DSP::GetPSTS()
+u16 DSi_DSP::GetPSTS() const
 {
     u16 r = DSP_PSTS & (1<<9); // this is the only sticky bit
     //r &= ~((1<<2)|(1<<7)); // we support instant resets and wrfifo xfers
@@ -182,7 +182,7 @@ void DSi_DSP::Reset()
     SNDExCnt = 0;
 }
 
-bool DSi_DSP::IsRstReleased()
+bool DSi_DSP::IsRstReleased() const
 {
     return SCFG_RST;
 }
@@ -193,12 +193,12 @@ void DSi_DSP::SetRstLine(bool release)
     DSPTimestamp = DSi.ARM9Timestamp; // only start now!
 }
 
-inline bool DSi_DSP::IsDSPCoreEnabled()
+inline bool DSi_DSP::IsDSPCoreEnabled() const
 {
     return (DSi.SCFG_Clock9 & (1<<1)) && SCFG_RST && (!(DSP_PCFG & (1<<0)));
 }
 
-inline bool DSi_DSP::IsDSPIOEnabled()
+inline bool DSi_DSP::IsDSPIOEnabled() const
 {
     return (DSi.SCFG_Clock9 & (1<<1)) && SCFG_RST;
 }