llvm/llvm/include/llvm/MC/MCParser/MCTargetAsmParser.h

//===- llvm/MC/MCTargetAsmParser.h - Target Assembly Parser -----*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_MC_MCPARSER_MCTARGETASMPARSER_H
#define LLVM_MC_MCPARSER_MCTARGETASMPARSER_H

#include "llvm/ADT/StringRef.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCParser/MCAsmParserExtension.h"
#include "llvm/MC/MCParser/MCParsedAsmOperand.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/TargetParser/SubtargetFeature.h"
#include <cstdint>
#include <memory>

namespace llvm {

class MCContext;
class MCInst;
class MCInstrInfo;
class MCRegister;
class MCStreamer;
class MCSubtargetInfo;
class MCSymbol;
template <typename T> class SmallVectorImpl;

OperandVector;

enum AsmRewriteKind { … };

const char AsmRewritePrecedence [] = …;

// Represent the various parts which make up an intel expression,
// used for emitting compound intel expressions
struct IntelExpr { … };

struct AsmRewrite { … };

struct ParseInstructionInfo { … };

enum OperandMatchResultTy { … };

/// Ternary parse status returned by various parse* methods.
class ParseStatus { … };

enum class DiagnosticPredicateTy { … };

// When an operand is parsed, the assembler will try to iterate through a set of
// possible operand classes that the operand might match and call the
// corresponding PredicateMethod to determine that.
//
// If there are two AsmOperands that would give a specific diagnostic if there
// is no match, there is currently no mechanism to distinguish which operand is
// a closer match. The DiagnosticPredicate distinguishes between 'completely
// no match' and 'near match', so the assembler can decide whether to give a
// specific diagnostic, or use 'InvalidOperand' and continue to find a
// 'better matching' diagnostic.
//
// For example:
//    opcode opnd0, onpd1, opnd2
//
// where:
//    opnd2 could be an 'immediate of range [-8, 7]'
//    opnd2 could be a  'register + shift/extend'.
//
// If opnd2 is a valid register, but with a wrong shift/extend suffix, it makes
// little sense to give a diagnostic that the operand should be an immediate
// in range [-8, 7].
//
// This is a light-weight alternative to the 'NearMissInfo' approach
// below which collects *all* possible diagnostics. This alternative
// is optional and fully backward compatible with existing
// PredicateMethods that return a 'bool' (match or no match).
struct DiagnosticPredicate { … };

// When matching of an assembly instruction fails, there may be multiple
// encodings that are close to being a match. It's often ambiguous which one
// the programmer intended to use, so we want to report an error which mentions
// each of these "near-miss" encodings. This struct contains information about
// one such encoding, and why it did not match the parsed instruction.
class NearMissInfo { … };

/// MCTargetAsmParser - Generic interface to target specific assembly parsers.
class MCTargetAsmParser : public MCAsmParserExtension { … };

} // end namespace llvm

#endif // LLVM_MC_MCPARSER_MCTARGETASMPARSER_H