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- //===-- lib/MC/Disassembler.cpp - Disassembler Public C Interface ---------===//
- //
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
- // See https://llvm.org/LICENSE.txt for license information.
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
- //
- //===----------------------------------------------------------------------===//
- #include "Disassembler.h"
- #include "llvm-c/Disassembler.h"
- #include "llvm/ADT/ArrayRef.h"
- #include "llvm/ADT/SmallVector.h"
- #include "llvm/ADT/Triple.h"
- #include "llvm/MC/MCAsmInfo.h"
- #include "llvm/MC/MCContext.h"
- #include "llvm/MC/MCDisassembler/MCDisassembler.h"
- #include "llvm/MC/MCDisassembler/MCRelocationInfo.h"
- #include "llvm/MC/MCDisassembler/MCSymbolizer.h"
- #include "llvm/MC/MCInst.h"
- #include "llvm/MC/MCInstPrinter.h"
- #include "llvm/MC/MCInstrDesc.h"
- #include "llvm/MC/MCInstrInfo.h"
- #include "llvm/MC/MCInstrItineraries.h"
- #include "llvm/MC/MCRegisterInfo.h"
- #include "llvm/MC/MCSchedule.h"
- #include "llvm/MC/MCSubtargetInfo.h"
- #include "llvm/MC/MCTargetOptions.h"
- #include "llvm/MC/TargetRegistry.h"
- #include "llvm/Support/ErrorHandling.h"
- #include "llvm/Support/FormattedStream.h"
- #include "llvm/Support/raw_ostream.h"
- #include <cassert>
- #include <cstring>
- 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
- LLVMCreateDisasmCPUFeatures(const char *TT, const char *CPU,
- const char *Features, void *DisInfo, int TagType,
- LLVMOpInfoCallback GetOpInfo,
- LLVMSymbolLookupCallback SymbolLookUp) {
- // Get the target.
- std::string Error;
- const Target *TheTarget = TargetRegistry::lookupTarget(TT, Error);
- if (!TheTarget)
- return nullptr;
- std::unique_ptr<const MCRegisterInfo> MRI(TheTarget->createMCRegInfo(TT));
- if (!MRI)
- return nullptr;
- MCTargetOptions MCOptions;
- // Get the assembler info needed to setup the MCContext.
- std::unique_ptr<const MCAsmInfo> MAI(
- TheTarget->createMCAsmInfo(*MRI, TT, MCOptions));
- if (!MAI)
- return nullptr;
- std::unique_ptr<const MCInstrInfo> MII(TheTarget->createMCInstrInfo());
- if (!MII)
- return nullptr;
- std::unique_ptr<const MCSubtargetInfo> STI(
- TheTarget->createMCSubtargetInfo(TT, CPU, Features));
- if (!STI)
- return nullptr;
- // Set up the MCContext for creating symbols and MCExpr's.
- std::unique_ptr<MCContext> Ctx(
- new MCContext(Triple(TT), MAI.get(), MRI.get(), STI.get()));
- if (!Ctx)
- return nullptr;
- // Set up disassembler.
- std::unique_ptr<MCDisassembler> DisAsm(
- TheTarget->createMCDisassembler(*STI, *Ctx));
- if (!DisAsm)
- return nullptr;
- std::unique_ptr<MCRelocationInfo> RelInfo(
- TheTarget->createMCRelocationInfo(TT, *Ctx));
- if (!RelInfo)
- return nullptr;
- std::unique_ptr<MCSymbolizer> Symbolizer(TheTarget->createMCSymbolizer(
- TT, GetOpInfo, SymbolLookUp, DisInfo, Ctx.get(), std::move(RelInfo)));
- DisAsm->setSymbolizer(std::move(Symbolizer));
- // Set up the instruction printer.
- int AsmPrinterVariant = MAI->getAssemblerDialect();
- std::unique_ptr<MCInstPrinter> IP(TheTarget->createMCInstPrinter(
- Triple(TT), AsmPrinterVariant, *MAI, *MII, *MRI));
- if (!IP)
- return nullptr;
- LLVMDisasmContext *DC = new LLVMDisasmContext(
- TT, DisInfo, TagType, GetOpInfo, SymbolLookUp, TheTarget, std::move(MAI),
- std::move(MRI), std::move(STI), std::move(MII), std::move(Ctx),
- std::move(DisAsm), std::move(IP));
- if (!DC)
- return nullptr;
- DC->setCPU(CPU);
- return DC;
- }
- LLVMDisasmContextRef
- LLVMCreateDisasmCPU(const char *TT, const char *CPU, void *DisInfo, int TagType,
- LLVMOpInfoCallback GetOpInfo,
- LLVMSymbolLookupCallback SymbolLookUp) {
- return LLVMCreateDisasmCPUFeatures(TT, CPU, "", DisInfo, TagType, GetOpInfo,
- SymbolLookUp);
- }
- LLVMDisasmContextRef LLVMCreateDisasm(const char *TT, void *DisInfo,
- int TagType, LLVMOpInfoCallback GetOpInfo,
- LLVMSymbolLookupCallback SymbolLookUp) {
- return LLVMCreateDisasmCPUFeatures(TT, "", "", DisInfo, TagType, GetOpInfo,
- SymbolLookUp);
- }
- //
- // LLVMDisasmDispose() disposes of the disassembler specified by the context.
- //
- void LLVMDisasmDispose(LLVMDisasmContextRef DCR){
- LLVMDisasmContext *DC = static_cast<LLVMDisasmContext *>(DCR);
- delete DC;
- }
- /// Emits the comments that are stored in \p DC comment stream.
- /// Each comment in the comment stream must end with a newline.
- static void emitComments(LLVMDisasmContext *DC,
- formatted_raw_ostream &FormattedOS) {
- // Flush the stream before taking its content.
- StringRef Comments = DC->CommentsToEmit.str();
- // Get the default information for printing a comment.
- const MCAsmInfo *MAI = DC->getAsmInfo();
- StringRef CommentBegin = MAI->getCommentString();
- unsigned CommentColumn = MAI->getCommentColumn();
- bool IsFirst = true;
- while (!Comments.empty()) {
- if (!IsFirst)
- FormattedOS << '\n';
- // Emit a line of comments.
- FormattedOS.PadToColumn(CommentColumn);
- size_t Position = Comments.find('\n');
- FormattedOS << CommentBegin << ' ' << Comments.substr(0, Position);
- // Move after the newline character.
- Comments = Comments.substr(Position+1);
- IsFirst = false;
- }
- FormattedOS.flush();
- // Tell the comment stream that the vector changed underneath it.
- DC->CommentsToEmit.clear();
- }
- /// Gets latency information for \p Inst from the itinerary
- /// scheduling model, based on \p DC information.
- /// \return The maximum expected latency over all the operands or -1
- /// if no information is available.
- static int getItineraryLatency(LLVMDisasmContext *DC, const MCInst &Inst) {
- const int NoInformationAvailable = -1;
- // Check if we have a CPU to get the itinerary information.
- if (DC->getCPU().empty())
- return NoInformationAvailable;
- // Get itinerary information.
- const MCSubtargetInfo *STI = DC->getSubtargetInfo();
- InstrItineraryData IID = STI->getInstrItineraryForCPU(DC->getCPU());
- // Get the scheduling class of the requested instruction.
- const MCInstrDesc& Desc = DC->getInstrInfo()->get(Inst.getOpcode());
- unsigned SCClass = Desc.getSchedClass();
- int Latency = 0;
- for (unsigned OpIdx = 0, OpIdxEnd = Inst.getNumOperands(); OpIdx != OpIdxEnd;
- ++OpIdx)
- Latency = std::max(Latency, IID.getOperandCycle(SCClass, OpIdx));
- return Latency;
- }
- /// Gets latency information for \p Inst, based on \p DC information.
- /// \return The maximum expected latency over all the definitions or -1
- /// if no information is available.
- static int getLatency(LLVMDisasmContext *DC, const MCInst &Inst) {
- // Try to compute scheduling information.
- const MCSubtargetInfo *STI = DC->getSubtargetInfo();
- const MCSchedModel SCModel = STI->getSchedModel();
- const int NoInformationAvailable = -1;
- // Check if we have a scheduling model for instructions.
- if (!SCModel.hasInstrSchedModel())
- // Try to fall back to the itinerary model if the scheduling model doesn't
- // have a scheduling table. Note the default does not have a table.
- return getItineraryLatency(DC, Inst);
- // Get the scheduling class of the requested instruction.
- const MCInstrDesc& Desc = DC->getInstrInfo()->get(Inst.getOpcode());
- unsigned SCClass = Desc.getSchedClass();
- const MCSchedClassDesc *SCDesc = SCModel.getSchedClassDesc(SCClass);
- // Resolving the variant SchedClass requires an MI to pass to
- // SubTargetInfo::resolveSchedClass.
- if (!SCDesc || !SCDesc->isValid() || SCDesc->isVariant())
- return NoInformationAvailable;
- // Compute output latency.
- int16_t Latency = 0;
- for (unsigned DefIdx = 0, DefEnd = SCDesc->NumWriteLatencyEntries;
- DefIdx != DefEnd; ++DefIdx) {
- // Lookup the definition's write latency in SubtargetInfo.
- const MCWriteLatencyEntry *WLEntry = STI->getWriteLatencyEntry(SCDesc,
- DefIdx);
- Latency = std::max(Latency, WLEntry->Cycles);
- }
- return Latency;
- }
- /// Emits latency information in DC->CommentStream for \p Inst, based
- /// on the information available in \p DC.
- static void emitLatency(LLVMDisasmContext *DC, const MCInst &Inst) {
- int Latency = getLatency(DC, Inst);
- // Report only interesting latencies.
- if (Latency < 2)
- return;
- DC->CommentStream << "Latency: " << Latency << '\n';
- }
- //
- // 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 = static_cast<LLVMDisasmContext *>(DCR);
- // Wrap the pointer to the Bytes, BytesSize and PC in a MemoryObject.
- ArrayRef<uint8_t> Data(Bytes, BytesSize);
- uint64_t Size;
- MCInst Inst;
- const MCDisassembler *DisAsm = DC->getDisAsm();
- MCInstPrinter *IP = DC->getIP();
- MCDisassembler::DecodeStatus S;
- SmallVector<char, 64> InsnStr;
- raw_svector_ostream Annotations(InsnStr);
- S = DisAsm->getInstruction(Inst, Size, Data, PC, Annotations);
- switch (S) {
- case MCDisassembler::Fail:
- case MCDisassembler::SoftFail:
- // FIXME: Do something different for soft failure modes?
- return 0;
- case MCDisassembler::Success: {
- StringRef AnnotationsStr = Annotations.str();
- SmallVector<char, 64> InsnStr;
- raw_svector_ostream OS(InsnStr);
- formatted_raw_ostream FormattedOS(OS);
- IP->printInst(&Inst, PC, AnnotationsStr, *DC->getSubtargetInfo(),
- FormattedOS);
- if (DC->getOptions() & LLVMDisassembler_Option_PrintLatency)
- emitLatency(DC, Inst);
- emitComments(DC, FormattedOS);
- 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;
- }
- }
- llvm_unreachable("Invalid DecodeStatus!");
- }
- //
- // LLVMSetDisasmOptions() sets the disassembler's options. It returns 1 if it
- // can set all the Options and 0 otherwise.
- //
- int LLVMSetDisasmOptions(LLVMDisasmContextRef DCR, uint64_t Options){
- if (Options & LLVMDisassembler_Option_UseMarkup){
- LLVMDisasmContext *DC = static_cast<LLVMDisasmContext *>(DCR);
- MCInstPrinter *IP = DC->getIP();
- IP->setUseMarkup(true);
- DC->addOptions(LLVMDisassembler_Option_UseMarkup);
- Options &= ~LLVMDisassembler_Option_UseMarkup;
- }
- if (Options & LLVMDisassembler_Option_PrintImmHex){
- LLVMDisasmContext *DC = static_cast<LLVMDisasmContext *>(DCR);
- MCInstPrinter *IP = DC->getIP();
- IP->setPrintImmHex(true);
- DC->addOptions(LLVMDisassembler_Option_PrintImmHex);
- Options &= ~LLVMDisassembler_Option_PrintImmHex;
- }
- if (Options & LLVMDisassembler_Option_AsmPrinterVariant){
- LLVMDisasmContext *DC = static_cast<LLVMDisasmContext *>(DCR);
- // Try to set up the new instruction printer.
- const MCAsmInfo *MAI = DC->getAsmInfo();
- const MCInstrInfo *MII = DC->getInstrInfo();
- const MCRegisterInfo *MRI = DC->getRegisterInfo();
- int AsmPrinterVariant = MAI->getAssemblerDialect();
- AsmPrinterVariant = AsmPrinterVariant == 0 ? 1 : 0;
- MCInstPrinter *IP = DC->getTarget()->createMCInstPrinter(
- Triple(DC->getTripleName()), AsmPrinterVariant, *MAI, *MII, *MRI);
- if (IP) {
- DC->setIP(IP);
- DC->addOptions(LLVMDisassembler_Option_AsmPrinterVariant);
- Options &= ~LLVMDisassembler_Option_AsmPrinterVariant;
- }
- }
- if (Options & LLVMDisassembler_Option_SetInstrComments) {
- LLVMDisasmContext *DC = static_cast<LLVMDisasmContext *>(DCR);
- MCInstPrinter *IP = DC->getIP();
- IP->setCommentStream(DC->CommentStream);
- DC->addOptions(LLVMDisassembler_Option_SetInstrComments);
- Options &= ~LLVMDisassembler_Option_SetInstrComments;
- }
- if (Options & LLVMDisassembler_Option_PrintLatency) {
- LLVMDisasmContext *DC = static_cast<LLVMDisasmContext *>(DCR);
- DC->addOptions(LLVMDisassembler_Option_PrintLatency);
- Options &= ~LLVMDisassembler_Option_PrintLatency;
- }
- return (Options == 0);
- }
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