forked from OSchip/llvm-project
148 lines
4.6 KiB
C++
148 lines
4.6 KiB
C++
//===- OutputSections.h -----------------------------------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLD_ELF_OUTPUT_SECTIONS_H
|
|
#define LLD_ELF_OUTPUT_SECTIONS_H
|
|
|
|
#include "Config.h"
|
|
#include "InputSection.h"
|
|
#include "LinkerScript.h"
|
|
#include "Relocations.h"
|
|
#include "lld/Common/LLVM.h"
|
|
#include "llvm/MC/StringTableBuilder.h"
|
|
#include "llvm/Object/ELF.h"
|
|
#include <array>
|
|
|
|
namespace lld {
|
|
namespace elf {
|
|
|
|
struct PhdrEntry;
|
|
class InputSection;
|
|
class InputSectionBase;
|
|
|
|
// This represents a section in an output file.
|
|
// It is composed of multiple InputSections.
|
|
// The writer creates multiple OutputSections and assign them unique,
|
|
// non-overlapping file offsets and VAs.
|
|
class OutputSection final : public BaseCommand, public SectionBase {
|
|
public:
|
|
OutputSection(StringRef Name, uint32_t Type, uint64_t Flags);
|
|
|
|
static bool classof(const SectionBase *S) {
|
|
return S->kind() == SectionBase::Output;
|
|
}
|
|
|
|
static bool classof(const BaseCommand *C);
|
|
|
|
uint64_t getLMA() const { return PtLoad ? Addr + PtLoad->LMAOffset : Addr; }
|
|
template <typename ELFT> void writeHeaderTo(typename ELFT::Shdr *SHdr);
|
|
|
|
uint32_t SectionIndex = UINT32_MAX;
|
|
unsigned SortRank;
|
|
|
|
uint32_t getPhdrFlags() const;
|
|
|
|
// Pointer to the PT_LOAD segment, which this section resides in. This field
|
|
// is used to correctly compute file offset of a section. When two sections
|
|
// share the same load segment, difference between their file offsets should
|
|
// be equal to difference between their virtual addresses. To compute some
|
|
// section offset we use the following formula: Off = Off_first + VA -
|
|
// VA_first, where Off_first and VA_first is file offset and VA of first
|
|
// section in PT_LOAD.
|
|
PhdrEntry *PtLoad = nullptr;
|
|
|
|
// Pointer to a relocation section for this section. Usually nullptr because
|
|
// we consume relocations, but if --emit-relocs is specified (which is rare),
|
|
// it may have a non-null value.
|
|
OutputSection *RelocationSection = nullptr;
|
|
|
|
// Initially this field is the number of InputSections that have been added to
|
|
// the OutputSection so far. Later on, after a call to assignAddresses, it
|
|
// corresponds to the Elf_Shdr member.
|
|
uint64_t Size = 0;
|
|
|
|
// The following fields correspond to Elf_Shdr members.
|
|
uint64_t Offset = 0;
|
|
uint64_t Addr = 0;
|
|
uint32_t ShName = 0;
|
|
|
|
void addSection(InputSection *IS);
|
|
|
|
// The following members are normally only used in linker scripts.
|
|
MemoryRegion *MemRegion = nullptr;
|
|
MemoryRegion *LMARegion = nullptr;
|
|
Expr AddrExpr;
|
|
Expr AlignExpr;
|
|
Expr LMAExpr;
|
|
Expr SubalignExpr;
|
|
std::vector<BaseCommand *> SectionCommands;
|
|
std::vector<StringRef> Phdrs;
|
|
llvm::Optional<std::array<uint8_t, 4>> Filler;
|
|
ConstraintKind Constraint = ConstraintKind::NoConstraint;
|
|
std::string Location;
|
|
std::string MemoryRegionName;
|
|
std::string LMARegionName;
|
|
bool NonAlloc = false;
|
|
bool Noload = false;
|
|
bool ExpressionsUseSymbols = false;
|
|
bool UsedInExpression = false;
|
|
bool InOverlay = false;
|
|
|
|
// Tracks whether the section has ever had an input section added to it, even
|
|
// if the section was later removed (e.g. because it is a synthetic section
|
|
// that wasn't needed). This is needed for orphan placement.
|
|
bool HasInputSections = false;
|
|
|
|
void finalize();
|
|
template <class ELFT> void writeTo(uint8_t *Buf);
|
|
template <class ELFT> void maybeCompress();
|
|
|
|
void sort(llvm::function_ref<int(InputSectionBase *S)> Order);
|
|
void sortInitFini();
|
|
void sortCtorsDtors();
|
|
|
|
private:
|
|
// Used for implementation of --compress-debug-sections option.
|
|
std::vector<uint8_t> ZDebugHeader;
|
|
llvm::SmallVector<char, 1> CompressedData;
|
|
|
|
std::array<uint8_t, 4> getFiller();
|
|
};
|
|
|
|
int getPriority(StringRef S);
|
|
|
|
std::vector<InputSection *> getInputSections(OutputSection* OS);
|
|
|
|
// All output sections that are handled by the linker specially are
|
|
// globally accessible. Writer initializes them, so don't use them
|
|
// until Writer is initialized.
|
|
struct Out {
|
|
static uint8_t *BufferStart;
|
|
static uint8_t First;
|
|
static PhdrEntry *TlsPhdr;
|
|
static OutputSection *ElfHeader;
|
|
static OutputSection *ProgramHeaders;
|
|
static OutputSection *PreinitArray;
|
|
static OutputSection *InitArray;
|
|
static OutputSection *FiniArray;
|
|
};
|
|
|
|
} // namespace elf
|
|
} // namespace lld
|
|
|
|
namespace lld {
|
|
namespace elf {
|
|
|
|
uint64_t getHeaderSize();
|
|
|
|
extern std::vector<OutputSection *> OutputSections;
|
|
} // namespace elf
|
|
} // namespace lld
|
|
|
|
#endif
|