1 //===-- llvm/MC/MCValue.h - MCValue class -----------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains the declaration of the MCValue class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_MC_MCVALUE_H 14 #define LLVM_MC_MCVALUE_H 15 16 #include "llvm/MC/MCExpr.h" 17 #include "llvm/MC/MCSymbol.h" 18 #include "llvm/Support/DataTypes.h" 19 #include <cassert> 20 21 namespace llvm { 22 class MCAsmInfo; 23 class raw_ostream; 24 25 /// This represents an "assembler immediate". 26 /// 27 /// In its most general form, this can hold ":Kind:(SymbolA - SymbolB + 28 /// imm64)". Not all targets supports relocations of this general form, but we 29 /// need to represent this anyway. 30 /// 31 /// In general both SymbolA and SymbolB will also have a modifier 32 /// analogous to the top-level Kind. Current targets are not expected 33 /// to make use of both though. The choice comes down to whether 34 /// relocation modifiers apply to the closest symbol or the whole 35 /// expression. 36 /// 37 /// Note that this class must remain a simple POD value class, because we need 38 /// it to live in unions etc. 39 class MCValue { 40 const MCSymbolRefExpr *SymA = nullptr, *SymB = nullptr; 41 int64_t Cst = 0; 42 uint32_t RefKind = 0; 43 44 public: 45 MCValue() = default; getConstant()46 int64_t getConstant() const { return Cst; } getSymA()47 const MCSymbolRefExpr *getSymA() const { return SymA; } getSymB()48 const MCSymbolRefExpr *getSymB() const { return SymB; } getRefKind()49 uint32_t getRefKind() const { return RefKind; } 50 51 /// Is this an absolute (as opposed to relocatable) value. isAbsolute()52 bool isAbsolute() const { return !SymA && !SymB; } 53 54 /// Print the value to the stream \p OS. 55 void print(raw_ostream &OS) const; 56 57 /// Print the value to stderr. 58 void dump() const; 59 60 MCSymbolRefExpr::VariantKind getAccessVariant() const; 61 62 static MCValue get(const MCSymbolRefExpr *SymA, 63 const MCSymbolRefExpr *SymB = nullptr, 64 int64_t Val = 0, uint32_t RefKind = 0) { 65 MCValue R; 66 R.Cst = Val; 67 R.SymA = SymA; 68 R.SymB = SymB; 69 R.RefKind = RefKind; 70 return R; 71 } 72 get(int64_t Val)73 static MCValue get(int64_t Val) { 74 MCValue R; 75 R.Cst = Val; 76 R.SymA = nullptr; 77 R.SymB = nullptr; 78 R.RefKind = 0; 79 return R; 80 } 81 82 }; 83 84 } // end namespace llvm 85 86 #endif 87