LLVM 19.0.0git
Public Member Functions | List of all members
llvm::MCAsmLayout Class Reference

Encapsulates the layout of an assembly file at a particular point in time. More...

#include "llvm/MC/MCAsmLayout.h"

Public Member Functions

 MCAsmLayout (MCAssembler &Assembler)
 
MCAssemblergetAssembler () const
 Get the assembler object this is a layout for.
 
bool canGetFragmentOffset (const MCFragment *F) const
 
void invalidateFragmentsFrom (MCFragment *F)
 Invalidate the fragments starting with F because it has been resized.
 
void layoutFragment (MCFragment *Fragment)
 Perform layout for a single fragment, assuming that the previous fragment has already been laid out correctly, and the parent section has been initialized.
 
Section Access (in layout order)
llvm::SmallVectorImpl< MCSection * > & getSectionOrder ()
 
const llvm::SmallVectorImpl< MCSection * > & getSectionOrder () const
 
Fragment Layout Data
uint64_t getFragmentOffset (const MCFragment *F) const
 Get the offset of the given fragment inside its containing section.
 
Utility Functions
uint64_t getSectionAddressSize (const MCSection *Sec) const
 Get the address space size of the given section, as it effects layout.
 
uint64_t getSectionFileSize (const MCSection *Sec) const
 Get the data size of the given section, as emitted to the object file.
 
bool getSymbolOffset (const MCSymbol &S, uint64_t &Val) const
 Get the offset of the given symbol, as computed in the current layout.
 
uint64_t getSymbolOffset (const MCSymbol &S) const
 Variant that reports a fatal error if the offset is not computable.
 
const MCSymbolgetBaseSymbol (const MCSymbol &Symbol) const
 If this symbol is equivalent to A + Constant, return A.
 

Detailed Description

Encapsulates the layout of an assembly file at a particular point in time.

Assembly may require computing multiple layouts for a particular assembly file as part of the relaxation process. This class encapsulates the layout at a single point in time in such a way that it is always possible to efficiently compute the exact address of any symbol in the assembly file, even during the relaxation process.

Definition at line 28 of file MCAsmLayout.h.

Constructor & Destructor Documentation

◆ MCAsmLayout()

MCAsmLayout::MCAsmLayout ( MCAssembler Assembler)

Definition at line 32 of file MCFragment.cpp.

Member Function Documentation

◆ canGetFragmentOffset()

bool MCAsmLayout::canGetFragmentOffset ( const MCFragment F) const
Returns
whether the offset of fragment F can be obtained via getFragmentOffset.

Definition at line 51 of file MCFragment.cpp.

References llvm::MCSection::begin(), F, llvm::MCFragment::getLayoutOrder(), and I.

Referenced by AttemptToFoldSymbolOffsetDifference().

◆ getAssembler()

MCAssembler & llvm::MCAsmLayout::getAssembler ( ) const
inline

◆ getBaseSymbol()

const MCSymbol * MCAsmLayout::getBaseSymbol ( const MCSymbol Symbol) const

◆ getFragmentOffset()

uint64_t MCAsmLayout::getFragmentOffset ( const MCFragment F) const

Get the offset of the given fragment inside its containing section.

Definition at line 96 of file MCFragment.cpp.

References assert(), and F.

Referenced by llvm::MCAssembler::computeFragmentSize(), llvm::RISCVAsmBackend::evaluateTargetFixup(), llvm::MachObjectWriter::getFragmentAddress(), getLabelOffset(), and getSectionAddressSize().

◆ getSectionAddressSize()

uint64_t MCAsmLayout::getSectionAddressSize ( const MCSection Sec) const

Get the address space size of the given section, as it effects layout.

This may differ from the size reported by

See also
getSectionFileSize() by not including section tail padding.

Definition at line 198 of file MCFragment.cpp.

References llvm::MCAssembler::computeFragmentSize(), F, getAssembler(), llvm::MCSection::getFragmentList(), and getFragmentOffset().

Referenced by llvm::MachObjectWriter::computeSectionAddresses(), llvm::MachObjectWriter::getPaddingSize(), getSectionFileSize(), llvm::MachObjectWriter::writeObject(), llvm::MachObjectWriter::writeSection(), and llvm::MCAssembler::writeSectionData().

◆ getSectionFileSize()

uint64_t MCAsmLayout::getSectionFileSize ( const MCSection Sec) const

Get the data size of the given section, as emitted to the object file.

This may include additional padding, or be 0 for virtual sections.

Definition at line 204 of file MCFragment.cpp.

References getSectionAddressSize(), and llvm::MCSection::isVirtualSection().

Referenced by llvm::MachObjectWriter::writeObject(), llvm::MachObjectWriter::writeSection(), and llvm::MCAssembler::writeSectionData().

◆ getSectionOrder() [1/2]

llvm::SmallVectorImpl< MCSection * > & llvm::MCAsmLayout::getSectionOrder ( )
inline

◆ getSectionOrder() [2/2]

const llvm::SmallVectorImpl< MCSection * > & llvm::MCAsmLayout::getSectionOrder ( ) const
inline

Definition at line 70 of file MCAsmLayout.h.

◆ getSymbolOffset() [1/2]

uint64_t MCAsmLayout::getSymbolOffset ( const MCSymbol S) const

Variant that reports a fatal error if the offset is not computable.

Definition at line 156 of file MCFragment.cpp.

References getSymbolOffsetImpl().

◆ getSymbolOffset() [2/2]

bool MCAsmLayout::getSymbolOffset ( const MCSymbol S,
uint64_t Val 
) const

Get the offset of the given symbol, as computed in the current layout.

Returns
True on success.

Definition at line 152 of file MCFragment.cpp.

References getSymbolOffsetImpl().

Referenced by AttemptToFoldSymbolOffsetDifference(), llvm::MCAssembler::computeFragmentSize(), llvm::RISCVAsmBackend::evaluateTargetFixup(), llvm::MachObjectWriter::getSymbolAddress(), and getSymbolValue().

◆ invalidateFragmentsFrom()

void MCAsmLayout::invalidateFragmentsFrom ( MCFragment F)

Invalidate the fragments starting with F because it has been resized.

The fragment's size should have already been updated, but its bundle padding will be recomputed.

Definition at line 70 of file MCFragment.cpp.

References F.

Referenced by llvm::MCAssembler::layout().

◆ layoutFragment()

void MCAsmLayout::layoutFragment ( MCFragment Fragment)

Perform layout for a single fragment, assuming that the previous fragment has already been laid out correctly, and the parent section has been initialized.

Definition at line 407 of file MCAssembler.cpp.

References assert(), llvm::computeBundlePadding(), llvm::MCAssembler::computeFragmentSize(), F, getAssembler(), llvm::MCAssembler::getBundleAlignSize(), llvm::MCAssembler::getRelaxAll(), llvm::MCAssembler::isBundlingEnabled(), llvm::report_fatal_error(), and llvm::MCEncodedFragment::setBundlePadding().


The documentation for this class was generated from the following files: