WebSVN – QNX 8.QNX8 LLVM/Clang compiler suite – Blame – /llvm-build/x86_64/include/llvm/MC/MCFixup.h

Rev	Author	Line No.	Line
14	pmbaty	1	//===-- llvm/MC/MCFixup.h - Instruction Relocation and Patching -- 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	#ifndef LLVM_MC_MCFIXUP_H
		10	#define LLVM_MC_MCFIXUP_H
		11
		12	#include "llvm/Support/DataTypes.h"
		13	#include "llvm/Support/ErrorHandling.h"
		14	#include "llvm/Support/SMLoc.h"
		15	#include <cassert>
		16
		17	namespace llvm {
		18	class MCExpr;
		19
		20	/// Extensible enumeration to represent the type of a fixup.
		21	enum MCFixupKind {
		22	FK_NONE = 0, ///< A no-op fixup.
		23	FK_Data_1, ///< A one-byte fixup.
		24	FK_Data_2, ///< A two-byte fixup.
		25	FK_Data_4, ///< A four-byte fixup.
		26	FK_Data_8, ///< A eight-byte fixup.
		27	FK_Data_6b, ///< A six-bits fixup.
		28	FK_PCRel_1, ///< A one-byte pc relative fixup.
		29	FK_PCRel_2, ///< A two-byte pc relative fixup.
		30	FK_PCRel_4, ///< A four-byte pc relative fixup.
		31	FK_PCRel_8, ///< A eight-byte pc relative fixup.
		32	FK_GPRel_1, ///< A one-byte gp relative fixup.
		33	FK_GPRel_2, ///< A two-byte gp relative fixup.
		34	FK_GPRel_4, ///< A four-byte gp relative fixup.
		35	FK_GPRel_8, ///< A eight-byte gp relative fixup.
		36	FK_DTPRel_4, ///< A four-byte dtp relative fixup.
		37	FK_DTPRel_8, ///< A eight-byte dtp relative fixup.
		38	FK_TPRel_4, ///< A four-byte tp relative fixup.
		39	FK_TPRel_8, ///< A eight-byte tp relative fixup.
		40	FK_SecRel_1, ///< A one-byte section relative fixup.
		41	FK_SecRel_2, ///< A two-byte section relative fixup.
		42	FK_SecRel_4, ///< A four-byte section relative fixup.
		43	FK_SecRel_8, ///< A eight-byte section relative fixup.
		44
		45	FirstTargetFixupKind = 128,
		46
		47	/// The range [FirstLiteralRelocationKind, MaxTargetFixupKind) is used for
		48	/// relocations coming from .reloc directive. Fixup kind
		49	/// FirstLiteralRelocationKind+V represents the relocation type with number V.
		50	FirstLiteralRelocationKind = 256,
		51
		52	/// Set limit to accommodate the highest reloc type in use for all Targets,
		53	/// currently R_AARCH64_IRELATIVE at 1032, including room for expansion.
		54	MaxFixupKind = FirstLiteralRelocationKind + 1032 + 32,
		55	};
		56
		57	/// Encode information on a single operation to perform on a byte
		58	/// sequence (e.g., an encoded instruction) which requires assemble- or run-
		59	/// time patching.
		60	///
		61	/// Fixups are used any time the target instruction encoder needs to represent
		62	/// some value in an instruction which is not yet concrete. The encoder will
		63	/// encode the instruction assuming the value is 0, and emit a fixup which
		64	/// communicates to the assembler backend how it should rewrite the encoded
		65	/// value.
		66	///
		67	/// During the process of relaxation, the assembler will apply fixups as
		68	/// symbolic values become concrete. When relaxation is complete, any remaining
		69	/// fixups become relocations in the object file (or errors, if the fixup cannot
		70	/// be encoded on the target).
		71	class MCFixup {
		72	/// The value to put into the fixup location. The exact interpretation of the
		73	/// expression is target dependent, usually it will be one of the operands to
		74	/// an instruction or an assembler directive.
		75	const MCExpr *Value = nullptr;
		76
		77	/// The byte index of start of the relocation inside the MCFragment.
		78	uint32_t Offset = 0;
		79
		80	/// The target dependent kind of fixup item this is. The kind is used to
		81	/// determine how the operand value should be encoded into the instruction.
		82	MCFixupKind Kind = FK_NONE;
		83
		84	/// The source location which gave rise to the fixup, if any.
		85	SMLoc Loc;
		86	public:
		87	static MCFixup create(uint32_t Offset, const MCExpr *Value,
		88	MCFixupKind Kind, SMLoc Loc = SMLoc()) {
		89	assert(Kind <= MaxFixupKind && "Kind out of range!");
		90	MCFixup FI;
		91	FI.Value = Value;
		92	FI.Offset = Offset;
		93	FI.Kind = Kind;
		94	FI.Loc = Loc;
		95	return FI;
		96	}
		97
		98	MCFixupKind getKind() const { return Kind; }
		99
		100	unsigned getTargetKind() const { return Kind; }
		101
		102	uint32_t getOffset() const { return Offset; }
		103	void setOffset(uint32_t Value) { Offset = Value; }
		104
		105	const MCExpr *getValue() const { return Value; }
		106
		107	/// Return the generic fixup kind for a value with the given size. It
		108	/// is an error to pass an unsupported size.
		109	static MCFixupKind getKindForSize(unsigned Size, bool IsPCRel) {
		110	switch (Size) {
		111	default: llvm_unreachable("Invalid generic fixup size!");
		112	case 1:
		113	return IsPCRel ? FK_PCRel_1 : FK_Data_1;
		114	case 2:
		115	return IsPCRel ? FK_PCRel_2 : FK_Data_2;
		116	case 4:
		117	return IsPCRel ? FK_PCRel_4 : FK_Data_4;
		118	case 8:
		119	return IsPCRel ? FK_PCRel_8 : FK_Data_8;
		120	}
		121	}
		122
		123	/// Return the generic fixup kind for a value with the given size in bits.
		124	/// It is an error to pass an unsupported size.
		125	static MCFixupKind getKindForSizeInBits(unsigned Size, bool IsPCRel) {
		126	switch (Size) {
		127	default:
		128	llvm_unreachable("Invalid generic fixup size!");
		129	case 6:
		130	assert(!IsPCRel && "Invalid pc-relative fixup size!");
		131	return FK_Data_6b;
		132	case 8:
		133	return IsPCRel ? FK_PCRel_1 : FK_Data_1;
		134	case 16:
		135	return IsPCRel ? FK_PCRel_2 : FK_Data_2;
		136	case 32:
		137	return IsPCRel ? FK_PCRel_4 : FK_Data_4;
		138	case 64:
		139	return IsPCRel ? FK_PCRel_8 : FK_Data_8;
		140	}
		141	}
		142
		143	SMLoc getLoc() const { return Loc; }
		144	};
		145
		146	} // End llvm namespace
		147
		148	#endif

Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

QNX 8.QNX8 LLVM/Clang compiler suite/llvm-build/x86_64/include/llvm/MC/MCFixup.h – Rev 14