1 //===-- lib/MC/Disassembler.cpp - Disassembler Public C Interface -*- C -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "Disassembler.h"
11 #include "llvm-c/Disassembler.h"
13 #include "llvm/MC/MCAsmInfo.h"
14 #include "llvm/MC/MCDisassembler.h"
15 #include "llvm/MC/MCInst.h"
16 #include "llvm/MC/MCInstPrinter.h"
17 #include "llvm/MC/MCContext.h"
18 #include "llvm/Target/TargetRegistry.h"
19 #include "llvm/Target/TargetAsmInfo.h" // FIXME.
20 #include "llvm/Target/TargetMachine.h" // FIXME.
21 #include "llvm/Target/TargetSelect.h"
22 #include "llvm/Support/MemoryObject.h"
29 // LLVMCreateDisasm() creates a disassembler for the TripleName. Symbolic
30 // disassembly is supported by passing a block of information in the DisInfo
31 // parameter and specifying the TagType and callback functions as described in
32 // the header llvm-c/Disassembler.h . The pointer to the block and the
33 // functions can all be passed as NULL. If successful, this returns a
34 // disassembler context. If not, it returns NULL.
36 LLVMDisasmContextRef LLVMCreateDisasm(const char *TripleName, void *DisInfo,
37 int TagType, LLVMOpInfoCallback GetOpInfo,
38 LLVMSymbolLookupCallback SymbolLookUp) {
39 // Initialize targets and assembly printers/parsers.
40 llvm::InitializeAllTargetInfos();
41 // FIXME: We shouldn't need to initialize the Target(Machine)s.
42 llvm::InitializeAllTargets();
43 llvm::InitializeAllMCAsmInfos();
44 llvm::InitializeAllAsmPrinters();
45 llvm::InitializeAllAsmParsers();
46 llvm::InitializeAllDisassemblers();
50 const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
51 assert(TheTarget && "Unable to create target!");
53 // Get the assembler info needed to setup the MCContext.
54 const MCAsmInfo *MAI = TheTarget->createMCAsmInfo(TripleName);
55 assert(MAI && "Unable to create target asm info!");
57 // Package up features to be passed to target/subtarget
58 std::string FeaturesStr;
61 // FIXME: We shouldn't need to do this (and link in codegen).
62 // When we split this out, we should do it in a way that makes
63 // it straightforward to switch subtargets on the fly.
64 TargetMachine *TM = TheTarget->createTargetMachine(TripleName, CPU,
66 assert(TM && "Unable to create target machine!");
68 // Get the target assembler info needed to setup the context.
69 const TargetAsmInfo *tai = new TargetAsmInfo(*TM);
70 assert(tai && "Unable to create target assembler!");
72 // Set up the MCContext for creating symbols and MCExpr's.
73 MCContext *Ctx = new MCContext(*MAI, tai);
74 assert(Ctx && "Unable to create MCContext!");
76 // Set up disassembler.
77 MCDisassembler *DisAsm = TheTarget->createMCDisassembler();
78 assert(DisAsm && "Unable to create disassembler!");
79 DisAsm->setupForSymbolicDisassembly(GetOpInfo, DisInfo, Ctx);
81 // Set up the instruction printer.
82 int AsmPrinterVariant = MAI->getAssemblerDialect();
83 MCInstPrinter *IP = TheTarget->createMCInstPrinter(AsmPrinterVariant,
85 assert(IP && "Unable to create instruction printer!");
87 LLVMDisasmContext *DC = new LLVMDisasmContext(TripleName, DisInfo, TagType,
88 GetOpInfo, SymbolLookUp,
89 TheTarget, MAI, TM, tai, Ctx,
91 assert(DC && "Allocation failure!");
96 // LLVMDisasmDispose() disposes of the disassembler specified by the context.
98 void LLVMDisasmDispose(LLVMDisasmContextRef DCR){
99 LLVMDisasmContext *DC = (LLVMDisasmContext *)DCR;
105 // The memory object created by LLVMDisasmInstruction().
107 class DisasmMemoryObject : public MemoryObject {
112 DisasmMemoryObject(uint8_t *bytes, uint64_t size, uint64_t basePC) :
113 Bytes(bytes), Size(size), BasePC(basePC) {}
115 uint64_t getBase() const { return BasePC; }
116 uint64_t getExtent() const { return Size; }
118 int readByte(uint64_t Addr, uint8_t *Byte) const {
119 if (Addr - BasePC >= Size)
121 *Byte = Bytes[Addr - BasePC];
125 } // end anonymous namespace
128 // LLVMDisasmInstruction() disassembles a single instruction using the
129 // disassembler context specified in the parameter DC. The bytes of the
130 // instruction are specified in the parameter Bytes, and contains at least
131 // BytesSize number of bytes. The instruction is at the address specified by
132 // the PC parameter. If a valid instruction can be disassembled its string is
133 // returned indirectly in OutString which whos size is specified in the
134 // parameter OutStringSize. This function returns the number of bytes in the
135 // instruction or zero if there was no valid instruction. If this function
136 // returns zero the caller will have to pick how many bytes they want to step
137 // over by printing a .byte, .long etc. to continue.
139 size_t LLVMDisasmInstruction(LLVMDisasmContextRef DCR, uint8_t *Bytes,
140 uint64_t BytesSize, uint64_t PC, char *OutString,
141 size_t OutStringSize){
142 LLVMDisasmContext *DC = (LLVMDisasmContext *)DCR;
143 // Wrap the pointer to the Bytes, BytesSize and PC in a MemoryObject.
144 DisasmMemoryObject MemoryObject(Bytes, BytesSize, PC);
148 const MCDisassembler *DisAsm = DC->getDisAsm();
149 MCInstPrinter *IP = DC->getIP();
150 if (!DisAsm->getInstruction(Inst, Size, MemoryObject, PC, /*REMOVE*/ nulls()))
153 SmallVector<char, 64> InsnStr;
154 raw_svector_ostream OS(InsnStr);
155 IP->printInst(&Inst, OS);
158 assert(OutStringSize != 0 && "Output buffer cannot be zero size");
159 size_t OutputSize = std::min(OutStringSize-1, InsnStr.size());
160 std::memcpy(OutString, InsnStr.data(), OutputSize);
161 OutString[OutputSize] = '\0'; // Terminate string.