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//===-- lib/MC/Disassembler.cpp - Disassembler Public C Interface -*- C -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "Disassembler.h"
#include "llvm-c/Disassembler.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCDisassembler.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstPrinter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Target/TargetAsmInfo.h" // FIXME.
#include "llvm/Target/TargetMachine.h" // FIXME.
#include "llvm/Target/TargetSelect.h"
#include "llvm/Support/MemoryObject.h"
namespace llvm {
class Target;
} // namespace llvm
using namespace llvm;
// LLVMCreateDisasm() creates a disassembler for the TripleName. Symbolic
// disassembly is supported by passing a block of information in the DisInfo
// parameter and specifying the TagType and callback functions as described in
// the header llvm-c/Disassembler.h . The pointer to the block and the
// functions can all be passed as NULL. If successful, this returns a
// disassembler context. If not, it returns NULL.
//
LLVMDisasmContextRef LLVMCreateDisasm(const char *TripleName, void *DisInfo,
int TagType, LLVMOpInfoCallback GetOpInfo,
LLVMSymbolLookupCallback SymbolLookUp) {
// Initialize targets and assembly printers/parsers.
llvm::InitializeAllTargetInfos();
// FIXME: We shouldn't need to initialize the Target(Machine)s.
llvm::InitializeAllTargets();
llvm::InitializeAllAsmPrinters();
llvm::InitializeAllAsmParsers();
llvm::InitializeAllDisassemblers();
// Get the target.
std::string Error;
const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
assert(TheTarget && "Unable to create target!");
// Get the assembler info needed to setup the MCContext.
const MCAsmInfo *MAI = TheTarget->createAsmInfo(TripleName);
assert(MAI && "Unable to create target asm info!");
// Package up features to be passed to target/subtarget
std::string FeaturesStr;
std::string CPU;
// FIXME: We shouldn't need to do this (and link in codegen).
// When we split this out, we should do it in a way that makes
// it straightforward to switch subtargets on the fly.
TargetMachine *TM = TheTarget->createTargetMachine(TripleName, CPU,
FeaturesStr);
assert(TM && "Unable to create target machine!");
// Get the target assembler info needed to setup the context.
const TargetAsmInfo *tai = new TargetAsmInfo(*TM);
assert(tai && "Unable to create target assembler!");
// Set up the MCContext for creating symbols and MCExpr's.
MCContext *Ctx = new MCContext(*MAI, tai);
assert(Ctx && "Unable to create MCContext!");
// Set up disassembler.
MCDisassembler *DisAsm = TheTarget->createMCDisassembler();
assert(DisAsm && "Unable to create disassembler!");
DisAsm->setupForSymbolicDisassembly(GetOpInfo, DisInfo, Ctx);
// Set up the instruction printer.
int AsmPrinterVariant = MAI->getAssemblerDialect();
MCInstPrinter *IP = TheTarget->createMCInstPrinter(AsmPrinterVariant,
*MAI);
assert(IP && "Unable to create instruction printer!");
LLVMDisasmContext *DC = new LLVMDisasmContext(TripleName, DisInfo, TagType,
GetOpInfo, SymbolLookUp,
TheTarget, MAI, TM, tai, Ctx,
DisAsm, IP);
assert(DC && "Allocation failure!");
return DC;
}
//
// LLVMDisasmDispose() disposes of the disassembler specified by the context.
//
void LLVMDisasmDispose(LLVMDisasmContextRef DCR){
LLVMDisasmContext *DC = (LLVMDisasmContext *)DCR;
delete DC;
}
namespace {
//
// The memory object created by LLVMDisasmInstruction().
//
class DisasmMemoryObject : public MemoryObject {
uint8_t *Bytes;
uint64_t Size;
uint64_t BasePC;
public:
DisasmMemoryObject(uint8_t *bytes, uint64_t size, uint64_t basePC) :
Bytes(bytes), Size(size), BasePC(basePC) {}
uint64_t getBase() const { return BasePC; }
uint64_t getExtent() const { return Size; }
int readByte(uint64_t Addr, uint8_t *Byte) const {
if (Addr - BasePC >= Size)
return -1;
*Byte = Bytes[Addr - BasePC];
return 0;
}
};
} // end anonymous namespace
//
// LLVMDisasmInstruction() disassembles a single instruction using the
// disassembler context specified in the parameter DC. The bytes of the
// instruction are specified in the parameter Bytes, and contains at least
// BytesSize number of bytes. The instruction is at the address specified by
// the PC parameter. If a valid instruction can be disassembled its string is
// returned indirectly in OutString which whos size is specified in the
// parameter OutStringSize. This function returns the number of bytes in the
// instruction or zero if there was no valid instruction. If this function
// returns zero the caller will have to pick how many bytes they want to step
// over by printing a .byte, .long etc. to continue.
//
size_t LLVMDisasmInstruction(LLVMDisasmContextRef DCR, uint8_t *Bytes,
uint64_t BytesSize, uint64_t PC, char *OutString,
size_t OutStringSize){
LLVMDisasmContext *DC = (LLVMDisasmContext *)DCR;
// Wrap the pointer to the Bytes, BytesSize and PC in a MemoryObject.
DisasmMemoryObject MemoryObject(Bytes, BytesSize, PC);
uint64_t Size;
MCInst Inst;
const MCDisassembler *DisAsm = DC->getDisAsm();
MCInstPrinter *IP = DC->getIP();
if (!DisAsm->getInstruction(Inst, Size, MemoryObject, PC, /*REMOVE*/ nulls()))
return 0;
SmallVector<char, 64> InsnStr;
raw_svector_ostream OS(InsnStr);
IP->printInst(&Inst, OS);
OS.flush();
assert(OutStringSize != 0 && "Output buffer cannot be zero size");
size_t OutputSize = std::min(OutStringSize-1, InsnStr.size());
std::memcpy(OutString, InsnStr.data(), OutputSize);
OutString[OutputSize] = '\0'; // Terminate string.
return Size;
}
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