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::InitializeAllAsmPrinters();
44 llvm::InitializeAllAsmParsers();
45 llvm::InitializeAllDisassemblers();
49 const Target *TheTarget = TargetRegistry::lookupTarget(TripleName, Error);
50 assert(TheTarget && "Unable to create target!");
52 // Get the assembler info needed to setup the MCContext.
53 const MCAsmInfo *MAI = TheTarget->createAsmInfo(TripleName);
54 assert(MAI && "Unable to create target asm info!");
56 // Package up features to be passed to target/subtarget
57 std::string FeaturesStr;
59 // FIXME: We shouldn't need to do this (and link in codegen).
60 // When we split this out, we should do it in a way that makes
61 // it straightforward to switch subtargets on the fly.
62 TargetMachine *TM = TheTarget->createTargetMachine(TripleName, FeaturesStr);
63 assert(TM && "Unable to create target machine!");
65 // Get the target assembler info needed to setup the context.
66 const TargetAsmInfo *tai = new TargetAsmInfo(*TM);
67 assert(tai && "Unable to create target assembler!");
69 // Set up the MCContext for creating symbols and MCExpr's.
70 MCContext *Ctx = new MCContext(*MAI, tai);
71 assert(Ctx && "Unable to create MCContext!");
73 // Set up disassembler.
74 MCDisassembler *DisAsm = TheTarget->createMCDisassembler();
75 assert(DisAsm && "Unable to create disassembler!");
76 DisAsm->setupForSymbolicDisassembly(GetOpInfo, DisInfo, Ctx);
78 // Set up the instruction printer.
79 int AsmPrinterVariant = MAI->getAssemblerDialect();
80 MCInstPrinter *IP = TheTarget->createMCInstPrinter(*TM, AsmPrinterVariant,
82 assert(IP && "Unable to create instruction printer!");
84 LLVMDisasmContext *DC = new LLVMDisasmContext(TripleName, DisInfo, TagType,
85 GetOpInfo, SymbolLookUp,
86 TheTarget, MAI, TM, tai, Ctx,
88 assert(DC && "Allocation failure!");
93 // LLVMDisasmDispose() disposes of the disassembler specified by the context.
95 void LLVMDisasmDispose(LLVMDisasmContextRef DCR){
96 LLVMDisasmContext *DC = (LLVMDisasmContext *)DCR;
102 // The memory object created by LLVMDisasmInstruction().
104 class DisasmMemoryObject : public MemoryObject {
109 DisasmMemoryObject(uint8_t *bytes, uint64_t size, uint64_t basePC) :
110 Bytes(bytes), Size(size), BasePC(basePC) {}
112 uint64_t getBase() const { return BasePC; }
113 uint64_t getExtent() const { return Size; }
115 int readByte(uint64_t Addr, uint8_t *Byte) const {
116 if (Addr - BasePC >= Size)
118 *Byte = Bytes[Addr - BasePC];
122 } // end anonymous namespace
125 // LLVMDisasmInstruction() disassembles a single instruction using the
126 // disassembler context specified in the parameter DC. The bytes of the
127 // instruction are specified in the parameter Bytes, and contains at least
128 // BytesSize number of bytes. The instruction is at the address specified by
129 // the PC parameter. If a valid instruction can be disassembled its string is
130 // returned indirectly in OutString which whos size is specified in the
131 // parameter OutStringSize. This function returns the number of bytes in the
132 // instruction or zero if there was no valid instruction. If this function
133 // returns zero the caller will have to pick how many bytes they want to step
134 // over by printing a .byte, .long etc. to continue.
136 size_t LLVMDisasmInstruction(LLVMDisasmContextRef DCR, uint8_t *Bytes,
137 uint64_t BytesSize, uint64_t PC, char *OutString,
138 size_t OutStringSize){
139 LLVMDisasmContext *DC = (LLVMDisasmContext *)DCR;
140 // Wrap the pointer to the Bytes, BytesSize and PC in a MemoryObject.
141 DisasmMemoryObject MemoryObject(Bytes, BytesSize, PC);
145 const MCDisassembler *DisAsm = DC->getDisAsm();
146 MCInstPrinter *IP = DC->getIP();
147 if (!DisAsm->getInstruction(Inst, Size, MemoryObject, PC, /*REMOVE*/ nulls()))
150 SmallVector<char, 64> InsnStr;
151 raw_svector_ostream OS(InsnStr);
152 IP->printInst(&Inst, OS);
155 assert(OutStringSize != 0 && "Output buffer cannot be zero size");
156 size_t OutputSize = std::min(OutStringSize-1, InsnStr.size());
157 std::memcpy(OutString, InsnStr.data(), OutputSize);
158 OutString[OutputSize] = '\0'; // Terminate string.