class MCFixup

Declaration

class MCFixup { /* full declaration omitted */ };

Description

Encode information on a single operation to perform on a byte sequence (e.g., an encoded instruction) which requires assemble- or run- time patching. Fixups are used any time the target instruction encoder needs to represent some value in an instruction which is not yet concrete. The encoder will encode the instruction assuming the value is 0, and emit a fixup which communicates to the assembler backend how it should rewrite the encoded value. During the process of relaxation, the assembler will apply fixups as symbolic values become concrete. When relaxation is complete, any remaining fixups become relocations in the object file (or errors, if the fixup cannot be encoded on the target).

Declared at: llvm/include/llvm/MC/MCFixup.h:71

Member Variables

private const llvm::MCExpr* Value = nullptr

The value to put into the fixup location. The exact interpretation of the expression is target dependent, usually it will be one of the operands to an instruction or an assembler directive.

private uint32_t Offset = 0

The byte index of start of the relocation inside the MCFragment.

private llvm::MCFixupKind Kind = FK_NONE

The target dependent kind of fixup item this is. The kind is used to determine how the operand value should be encoded into the instruction.

private llvm::SMLoc Loc

The source location which gave rise to the fixup, if any.

Method Overview

• public static llvm::MCFixup create(uint32_t Offset, const llvm::MCExpr * Value, llvm::MCFixupKind Kind, llvm::SMLoc Loc = llvm::SMLoc())
• public llvm::MCFixupKind getKind() const
• public static llvm::MCFixupKind getKindForSize(unsigned int Size, bool IsPCRel)
• public static llvm::MCFixupKind getKindForSizeInBits(unsigned int Size, bool IsPCRel)
• public llvm::SMLoc getLoc() const
• public uint32_t getOffset() const
• public unsigned int getTargetKind() const
• public const llvm::MCExpr * getValue() const
• public void setOffset(uint32_t Value)

Methods

¶static llvm::MCFixup create(
    uint32_t Offset,
    const llvm::MCExpr* Value,
    llvm::MCFixupKind Kind,
    llvm::SMLoc Loc = llvm::SMLoc())

Declared at: llvm/include/llvm/MC/MCFixup.h:87

Parameters

uint32_t Offset

const llvm::MCExpr* Value

llvm::MCFixupKind Kind

llvm::SMLoc Loc = llvm::SMLoc()

¶llvm::MCFixupKind getKind() const

Declared at: llvm/include/llvm/MC/MCFixup.h:98

¶static llvm::MCFixupKind getKindForSize(
    unsigned int Size,
    bool IsPCRel)

Description

Return the generic fixup kind for a value with the given size. It is an error to pass an unsupported size.

Declared at: llvm/include/llvm/MC/MCFixup.h:109

Parameters

unsigned int Size

bool IsPCRel

¶static llvm::MCFixupKind getKindForSizeInBits(
    unsigned int Size,
    bool IsPCRel)

Description

Return the generic fixup kind for a value with the given size in bits. It is an error to pass an unsupported size.

Declared at: llvm/include/llvm/MC/MCFixup.h:125

Parameters

unsigned int Size

bool IsPCRel

¶llvm::SMLoc getLoc() const

Declared at: llvm/include/llvm/MC/MCFixup.h:143

¶uint32_t getOffset() const

Declared at: llvm/include/llvm/MC/MCFixup.h:102

¶unsigned int getTargetKind() const

Declared at: llvm/include/llvm/MC/MCFixup.h:100

¶const llvm::MCExpr* getValue() const

Declared at: llvm/include/llvm/MC/MCFixup.h:105

¶void setOffset(uint32_t Value)

Declared at: llvm/include/llvm/MC/MCFixup.h:103

Parameters

uint32_t Value