llvm-project/lld/ELF/Config.h

216 lines
6.3 KiB
C++

//===- Config.h -------------------------------------------------*- C++ -*-===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLD_ELF_CONFIG_H
#define LLD_ELF_CONFIG_H
#include "llvm/ADT/MapVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/ELF.h"
#include <vector>
namespace lld {
namespace elf {
class InputFile;
struct Symbol;
enum ELFKind {
ELFNoneKind,
ELF32LEKind,
ELF32BEKind,
ELF64LEKind,
ELF64BEKind
};
// For --build-id.
enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid };
// For --discard-{all,locals,none}.
enum class DiscardPolicy { Default, All, Locals, None };
// For --strip-{all,debug}.
enum class StripPolicy { None, All, Debug };
// For --unresolved-symbols.
enum class UnresolvedPolicy { ReportError, Warn, WarnAll, Ignore, IgnoreAll };
// For --sort-section and linkerscript sorting rules.
enum class SortSectionPolicy { Default, None, Alignment, Name, Priority };
// For --target2
enum class Target2Policy { Abs, Rel, GotRel };
struct SymbolVersion {
llvm::StringRef Name;
bool IsExternCpp;
bool HasWildcard;
};
// This struct contains symbols version definition that
// can be found in version script if it is used for link.
struct VersionDefinition {
VersionDefinition(llvm::StringRef Name, uint16_t Id) : Name(Name), Id(Id) {}
llvm::StringRef Name;
uint16_t Id;
std::vector<SymbolVersion> Globals;
size_t NameOff; // Offset in string table.
};
// This struct contains the global configuration for the linker.
// Most fields are direct mapping from the command line options
// and such fields have the same name as the corresponding options.
// Most fields are initialized by the driver.
struct Configuration {
InputFile *FirstElf = nullptr;
uint8_t OSABI = 0;
llvm::StringMap<uint64_t> SectionStartMap;
llvm::StringRef DynamicLinker;
llvm::StringRef Entry;
llvm::StringRef Emulation;
llvm::StringRef Fini;
llvm::StringRef Init;
llvm::StringRef LTOAAPipeline;
llvm::StringRef LTONewPmPasses;
llvm::StringRef MapFile;
llvm::StringRef OutputFile;
llvm::StringRef OptRemarksFilename;
llvm::StringRef SoName;
llvm::StringRef Sysroot;
llvm::StringRef ThinLTOCacheDir;
std::string RPath;
std::vector<VersionDefinition> VersionDefinitions;
std::vector<llvm::StringRef> AuxiliaryList;
std::vector<llvm::StringRef> SearchPaths;
std::vector<llvm::StringRef> SymbolOrderingFile;
std::vector<llvm::StringRef> Undefined;
std::vector<SymbolVersion> VersionScriptGlobals;
std::vector<SymbolVersion> VersionScriptLocals;
std::vector<uint8_t> BuildIdVector;
bool AllowMultipleDefinition;
bool AsNeeded = false;
bool Bsymbolic;
bool BsymbolicFunctions;
bool ColorDiagnostics = false;
bool DefineCommon;
bool Demangle = true;
bool DisableVerify;
bool EhFrameHdr;
bool EmitRelocs;
bool EnableNewDtags;
bool ExportDynamic;
bool FatalWarnings;
bool GcSections;
bool GdbIndex;
bool GnuHash;
bool ICF;
bool MipsN32Abi = false;
bool NoGnuUnique;
bool NoUndefinedVersion;
bool Nostdlib;
bool OFormatBinary;
bool Omagic;
bool OptRemarksWithHotness;
bool Pie;
bool PrintGcSections;
bool Rela;
bool Relocatable;
bool SaveTemps;
bool SingleRoRx;
bool Shared;
bool Static = false;
bool SysvHash;
bool Target1Rel;
bool Threads;
bool Trace;
bool Verbose;
bool WarnCommon;
bool WarnMissingEntry;
bool ZCombreloc;
bool ZExecstack;
bool ZNocopyreloc;
bool ZNodelete;
bool ZNow;
bool ZOrigin;
bool ZRelro;
bool ExitEarly;
bool ZWxneeded;
DiscardPolicy Discard;
SortSectionPolicy SortSection;
StripPolicy Strip;
UnresolvedPolicy UnresolvedSymbols;
Target2Policy Target2;
BuildIdKind BuildId = BuildIdKind::None;
ELFKind EKind = ELFNoneKind;
uint16_t DefaultSymbolVersion = llvm::ELF::VER_NDX_GLOBAL;
uint16_t EMachine = llvm::ELF::EM_NONE;
uint64_t ErrorLimit = 20;
uint64_t ImageBase;
uint64_t MaxPageSize;
uint64_t ZStackSize;
unsigned LTOPartitions;
unsigned LTOO;
unsigned Optimize;
unsigned ThinLTOJobs;
// The ELF spec defines two types of relocation table entries, RELA and
// REL. RELA is a triplet of (offset, info, addend) while REL is a
// tuple of (offset, info). Addends for REL are implicit and read from
// the location where the relocations are applied. So, REL is more
// compact than RELA but requires a bit of more work to process.
//
// (From the linker writer's view, this distinction is not necessary.
// If the ELF had chosen whichever and sticked with it, it would have
// been easier to write code to process relocations, but it's too late
// to change the spec.)
//
// Each ABI defines its relocation type. This function returns that.
// As far as we know, all 64-bit ABIs are using RELA. A few 32-bit ABIs
// are using RELA too.
bool isRela() const {
bool is64 = (EKind == ELF64LEKind || EKind == ELF64BEKind);
bool isX32Abi = (EKind == ELF32LEKind && EMachine == llvm::ELF::EM_X86_64);
return is64 || isX32Abi || MipsN32Abi;
}
// Returns true if we need to pass through relocations in input
// files to the output file. Usually false because we consume
// relocations.
bool copyRelocs() const { return Relocatable || EmitRelocs; }
// Returns true if we are creating position-independent code.
bool pic() const { return Pie || Shared; }
// Returns true if the target is the little-endian MIPS64. The reason
// why we have this function only for the MIPS is because we use this
// function often. Some ELF headers for MIPS64EL are in a mixed-endian
// (which is horrible and I'd say that's a serious spec bug), and we
// need to know whether we are reading MIPS ELF files or not in various
// places.
//
// (Note that MIPS64EL is not a typo for MIPS64LE. This is the official
// name whatever that means. A fun hypothesis is that "EL" is short for
// little-endian written in the little-endian order, but I don't know
// if that's true.)
bool isMips64EL() const {
return EMachine == llvm::ELF::EM_MIPS && EKind == ELF64LEKind;
}
};
// The only instance of Configuration struct.
extern Configuration *Config;
} // namespace elf
} // namespace lld
#endif