173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar//===-- llvm/MC/MCFixup.h - Instruction Relocation and Patching -*- C++ -*-===// 273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar// 373c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar// The LLVM Compiler Infrastructure 473c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar// 573c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar// This file is distributed under the University of Illinois Open Source 673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar// License. See LICENSE.TXT for details. 773c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar// 873c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar//===----------------------------------------------------------------------===// 973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 1073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar#ifndef LLVM_MC_MCFIXUP_H 1173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar#define LLVM_MC_MCFIXUP_H 1273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 131f6efa3996dd1929fbc129203ce5009b620e6969Michael J. Spencer#include "llvm/Support/DataTypes.h" 1450bee42b54cd9aec5f49566307df2b0cf23afcf6Craig Topper#include "llvm/Support/ErrorHandling.h" 1582f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach#include "llvm/Support/SMLoc.h" 1673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar#include <cassert> 1773c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 1873c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbarnamespace llvm { 195d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbarclass MCExpr; 2073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 2173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// MCFixupKind - Extensible enumeration to represent the type of a fixup. 2273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbarenum MCFixupKind { 2373c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar FK_Data_1 = 0, ///< A one-byte fixup. 2473c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar FK_Data_2, ///< A two-byte fixup. 2573c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar FK_Data_4, ///< A four-byte fixup. 2673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar FK_Data_8, ///< A eight-byte fixup. 27e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola FK_PCRel_1, ///< A one-byte pc relative fixup. 28e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola FK_PCRel_2, ///< A two-byte pc relative fixup. 29e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola FK_PCRel_4, ///< A four-byte pc relative fixup. 303a83c40ab61d5ca624f2bbadd70237c6adbdb304Rafael Espindola FK_PCRel_8, ///< A eight-byte pc relative fixup. 3184bfc2f090639f933df06cc675c4385511516befAkira Hatanaka FK_GPRel_1, ///< A one-byte gp relative fixup. 3284bfc2f090639f933df06cc675c4385511516befAkira Hatanaka FK_GPRel_2, ///< A two-byte gp relative fixup. 3384bfc2f090639f933df06cc675c4385511516befAkira Hatanaka FK_GPRel_4, ///< A four-byte gp relative fixup. 3484bfc2f090639f933df06cc675c4385511516befAkira Hatanaka FK_GPRel_8, ///< A eight-byte gp relative fixup. 35ce618af3e880ae0ec0ddd81aca8ed5bbd4096ae4Rafael Espindola FK_SecRel_1, ///< A one-byte section relative fixup. 36ce618af3e880ae0ec0ddd81aca8ed5bbd4096ae4Rafael Espindola FK_SecRel_2, ///< A two-byte section relative fixup. 37ce618af3e880ae0ec0ddd81aca8ed5bbd4096ae4Rafael Espindola FK_SecRel_4, ///< A four-byte section relative fixup. 38ce618af3e880ae0ec0ddd81aca8ed5bbd4096ae4Rafael Espindola FK_SecRel_8, ///< A eight-byte section relative fixup. 3973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 400dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar FirstTargetFixupKind = 128, 4173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 420dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar // Limit range of target fixups, in case we want to pack more efficiently 430dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar // later. 440dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar MaxTargetFixupKind = (1 << 8) 4573c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar}; 4673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 470dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar/// MCFixup - Encode information on a single operation to perform on a byte 4873c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// sequence (e.g., an encoded instruction) which requires assemble- or run- 4973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// time patching. 5073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// 5173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// Fixups are used any time the target instruction encoder needs to represent 5273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// some value in an instruction which is not yet concrete. The encoder will 5373c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// encode the instruction assuming the value is 0, and emit a fixup which 5473c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// communicates to the assembler backend how it should rewrite the encoded 5573c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// value. 5673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// 5773c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// During the process of relaxation, the assembler will apply fixups as 5873c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// symbolic values become concrete. When relaxation is complete, any remaining 5973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// fixups become relocations in the object file (or errors, if the fixup cannot 6073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar/// be encoded on the target). 6173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbarclass MCFixup { 625d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbar /// The value to put into the fixup location. The exact interpretation of the 630dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar /// expression is target dependent, usually it will be one of the operands to 640dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar /// an instruction or an assembler directive. 655d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbar const MCExpr *Value; 665d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbar 6773c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar /// The byte index of start of the relocation inside the encoded instruction. 680dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar uint32_t Offset; 6973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 7073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar /// The target dependent kind of fixup item this is. The kind is used to 7173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar /// determine how the operand value should be encoded into the instruction. 720dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar unsigned Kind; 7373c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 7482f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach /// The source location which gave rise to the fixup, if any. 7582f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach SMLoc Loc; 7673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbarpublic: 770dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar static MCFixup Create(uint32_t Offset, const MCExpr *Value, 7882f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach MCFixupKind Kind, SMLoc Loc = SMLoc()) { 790dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar assert(unsigned(Kind) < MaxTargetFixupKind && "Kind out of range!"); 8073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar MCFixup FI; 815d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbar FI.Value = Value; 8273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar FI.Offset = Offset; 8373c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar FI.Kind = unsigned(Kind); 8482f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach FI.Loc = Loc; 8573c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar return FI; 8673c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar } 8773c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 885d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbar MCFixupKind getKind() const { return MCFixupKind(Kind); } 8973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 900dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar uint32_t getOffset() const { return Offset; } 910dd0c941c9eb4adc13319ed7adcaffe58a68d294Daniel Dunbar void setOffset(uint32_t Value) { Offset = Value; } 9273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 935d5a1e13a129e18ee6031fe6354acd2ab4d39f37Daniel Dunbar const MCExpr *getValue() const { return Value; } 942be2fd073003c0988723d2894dfb117ad90be11bDaniel Dunbar 952be2fd073003c0988723d2894dfb117ad90be11bDaniel Dunbar /// getKindForSize - Return the generic fixup kind for a value with the given 962be2fd073003c0988723d2894dfb117ad90be11bDaniel Dunbar /// size. It is an error to pass an unsupported size. 97e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola static MCFixupKind getKindForSize(unsigned Size, bool isPCRel) { 982be2fd073003c0988723d2894dfb117ad90be11bDaniel Dunbar switch (Size) { 9950bee42b54cd9aec5f49566307df2b0cf23afcf6Craig Topper default: llvm_unreachable("Invalid generic fixup size!"); 100e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola case 1: return isPCRel ? FK_PCRel_1 : FK_Data_1; 101e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola case 2: return isPCRel ? FK_PCRel_2 : FK_Data_2; 102e04ed7e45f194f14a7b28bbf3f55694d8e2bcf80Rafael Espindola case 4: return isPCRel ? FK_PCRel_4 : FK_Data_4; 1033a83c40ab61d5ca624f2bbadd70237c6adbdb304Rafael Espindola case 8: return isPCRel ? FK_PCRel_8 : FK_Data_8; 1042be2fd073003c0988723d2894dfb117ad90be11bDaniel Dunbar } 1052be2fd073003c0988723d2894dfb117ad90be11bDaniel Dunbar } 10682f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach 10782f4ce5081fc9cfbf34bbe61eb0412e7ca4dc3dfJim Grosbach SMLoc getLoc() const { return Loc; } 10873c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar}; 10973c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 11073c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar} // End llvm namespace 11173c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar 11273c557458c0e28899f37c557bcaf36c2b6701260Daniel Dunbar#endif 113