88 lines
2.3 KiB
C++
88 lines
2.3 KiB
C++
// Copyright 2013 Dolphin Emulator Project
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// Licensed under GPLv2
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// Refer to the license.txt file included.
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#pragma once
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#include "common_types.h"
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#include "memory_util.h"
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// Everything that needs to generate code should inherit from this.
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// You get memory management for free, plus, you can use all emitter functions without
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// having to prefix them with gen-> or something similar.
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// Example implementation:
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// class JIT : public CodeBlock<ARMXEmitter> {}
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template<class T> class CodeBlock : public T, NonCopyable
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{
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private:
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// A privately used function to set the executable RAM space to something invalid.
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// For debugging usefulness it should be used to set the RAM to a host specific breakpoint instruction
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virtual void PoisonMemory() = 0;
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protected:
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u8 *region;
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size_t region_size;
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public:
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CodeBlock() : region(nullptr), region_size(0) {}
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virtual ~CodeBlock() { if (region) FreeCodeSpace(); }
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// Call this before you generate any code.
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void AllocCodeSpace(int size)
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{
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region_size = size;
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region = (u8*)AllocateExecutableMemory(region_size);
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T::SetCodePtr(region);
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}
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// Always clear code space with breakpoints, so that if someone accidentally executes
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// uninitialized, it just breaks into the debugger.
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void ClearCodeSpace()
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{
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PoisonMemory();
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ResetCodePtr();
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}
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// Call this when shutting down. Don't rely on the destructor, even though it'll do the job.
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void FreeCodeSpace()
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{
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#ifdef __SYMBIAN32__
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ResetExecutableMemory(region);
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#else
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FreeMemoryPages(region, region_size);
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#endif
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region = nullptr;
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region_size = 0;
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}
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bool IsInSpace(const u8 *ptr)
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{
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return (ptr >= region) && (ptr < (region + region_size));
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}
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// Cannot currently be undone. Will write protect the entire code region.
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// Start over if you need to change the code (call FreeCodeSpace(), AllocCodeSpace()).
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void WriteProtect()
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{
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WriteProtectMemory(region, region_size, true);
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}
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void ResetCodePtr()
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{
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T::SetCodePtr(region);
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}
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size_t GetSpaceLeft() const
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{
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return region_size - (T::GetCodePtr() - region);
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}
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u8 *GetBasePtr() {
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return region;
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}
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size_t GetOffset(const u8 *ptr) const {
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return ptr - region;
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}
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};
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