1 //===-- llvm/MC/MCValue.h - MCValue class -----------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains the declaration of the MCValue class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_MC_MCVALUE_H 15 #define LLVM_MC_MCVALUE_H 16 17 #include "llvm/MC/MCExpr.h" 18 #include "llvm/MC/MCSymbol.h" 19 #include "llvm/Support/DataTypes.h" 20 #include <cassert> 21 22 namespace llvm { 23 class MCAsmInfo; 24 class raw_ostream; 25 26 /// This represents an "assembler immediate". 27 /// 28 /// In its most general form, this can hold ":Kind:(SymbolA - SymbolB + 29 /// imm64)". Not all targets supports relocations of this general form, but we 30 /// need to represent this anyway. 31 /// 32 /// In general both SymbolA and SymbolB will also have a modifier 33 /// analogous to the top-level Kind. Current targets are not expected 34 /// to make use of both though. The choice comes down to whether 35 /// relocation modifiers apply to the closest symbol or the whole 36 /// expression. 37 /// 38 /// Note that this class must remain a simple POD value class, because we need 39 /// it to live in unions etc. 40 class MCValue { 41 const MCSymbolRefExpr *SymA = nullptr, *SymB = nullptr; 42 int64_t Cst = 0; 43 uint32_t RefKind = 0; 44 45 public: 46 MCValue() = default; getConstant()47 int64_t getConstant() const { return Cst; } getSymA()48 const MCSymbolRefExpr *getSymA() const { return SymA; } getSymB()49 const MCSymbolRefExpr *getSymB() const { return SymB; } getRefKind()50 uint32_t getRefKind() const { return RefKind; } 51 52 /// Is this an absolute (as opposed to relocatable) value. isAbsolute()53 bool isAbsolute() const { return !SymA && !SymB; } 54 55 /// Print the value to the stream \p OS. 56 void print(raw_ostream &OS) const; 57 58 /// Print the value to stderr. 59 void dump() const; 60 61 MCSymbolRefExpr::VariantKind getAccessVariant() const; 62 63 static MCValue get(const MCSymbolRefExpr *SymA, 64 const MCSymbolRefExpr *SymB = nullptr, 65 int64_t Val = 0, uint32_t RefKind = 0) { 66 MCValue R; 67 R.Cst = Val; 68 R.SymA = SymA; 69 R.SymB = SymB; 70 R.RefKind = RefKind; 71 return R; 72 } 73 get(int64_t Val)74 static MCValue get(int64_t Val) { 75 MCValue R; 76 R.Cst = Val; 77 R.SymA = nullptr; 78 R.SymB = nullptr; 79 R.RefKind = 0; 80 return R; 81 } 82 83 }; 84 85 } // end namespace llvm 86 87 #endif 88