llvm/llvm/lib/MC/MCDisassembler/MCExternalSymbolizer.cpp

//===-- MCExternalSymbolizer.cpp - External symbolizer --------------------===//
//
// 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 "llvm/MC/MCDisassembler/MCExternalSymbolizer.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include <cstring>

usingnamespacellvm;

namespace llvm {
class Triple;
}

// This function tries to add a symbolic operand in place of the immediate
// Value in the MCInst. The immediate Value has had any PC adjustment made by
// the caller. If the instruction is a branch instruction then IsBranch is true,
// else false. If the getOpInfo() function was set as part of the
// setupForSymbolicDisassembly() call then that function is called to get any
// symbolic information at the Address for this instruction. If that returns
// non-zero then the symbolic information it returns is used to create an MCExpr
// and that is added as an operand to the MCInst. If getOpInfo() returns zero
// and IsBranch is true then a symbol look up for Value is done and if a symbol
// is found an MCExpr is created with that, else an MCExpr with Value is
// created. This function returns true if it adds an operand to the MCInst and
// false otherwise.
bool MCExternalSymbolizer::tryAddingSymbolicOperand(
    MCInst &MI, raw_ostream &cStream, int64_t Value, uint64_t Address,
    bool IsBranch, uint64_t Offset, uint64_t OpSize, uint64_t InstSize) { … }

// This function tries to add a comment as to what is being referenced by a load
// instruction with the base register that is the Pc.  These can often be values
// in a literal pool near the Address of the instruction. The Address of the
// instruction and its immediate Value are used as a possible literal pool entry.
// The SymbolLookUp call back will return the name of a symbol referenced by the
// literal pool's entry if the referenced address is that of a symbol. Or it
// will return a pointer to a literal 'C' string if the referenced address of
// the literal pool's entry is an address into a section with C string literals.
// Or if the reference is to an Objective-C data structure it will return a
// specific reference type for it and a string.
void MCExternalSymbolizer::tryAddingPcLoadReferenceComment(raw_ostream &cStream,
                                                           int64_t Value,
                                                           uint64_t Address) { … }

namespace llvm {
MCSymbolizer *createMCSymbolizer(const Triple &TT, LLVMOpInfoCallback GetOpInfo,
                                 LLVMSymbolLookupCallback SymbolLookUp,
                                 void *DisInfo, MCContext *Ctx,
                                 std::unique_ptr<MCRelocationInfo> &&RelInfo) { … }
}