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llvm/llvm-project/edde212818e3bd1c19ade3cf52927bb7cdfd520f/./llvm/lib/Object/ArchiveWriter.cpp
blob: 4ed09b96bbcdeaf8dfead279611c3bcfa0befbe5 [file]
//===- ArchiveWriter.cpp - ar File Format implementation --------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file defines the writeArchive function.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/ArchiveWriter.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/Magic.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/Object/Archive.h"
#include "llvm/Object/COFF.h"
#include "llvm/Object/COFFImportFile.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/GOFFObjectFile.h"
#include "llvm/Object/IRObjectFile.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Object/XCOFFObjectFile.h"
#include "llvm/Support/Alignment.h"
#include "llvm/Support/EndianStream.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/SmallVectorMemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <cerrno>
#include <map>
#if !defined(_MSC_VER) && !defined(__MINGW32__)
#include <unistd.h>
#else
#include <io.h>
#endif
using namespace llvm;
using namespace llvm::object;
struct SymMap {
bool UseECMap = false;
std::map<std::string, uint16_t> Map;
std::map<std::string, uint16_t> ECMap;
};
NewArchiveMember::NewArchiveMember(MemoryBufferRef BufRef)
: Buf(MemoryBuffer::getMemBuffer(BufRef, false)),
MemberName(BufRef.getBufferIdentifier()) {}
object::Archive::Kind NewArchiveMember::detectKindFromObject() const {
auto MemBufferRef = this->Buf->getMemBufferRef();
Expected<std::unique_ptr<object::ObjectFile>> OptionalObject =
object::ObjectFile::createObjectFile(MemBufferRef);
if (OptionalObject) {
if (isa<object::MachOObjectFile>(**OptionalObject))
return object::Archive::K_DARWIN;
if (isa<object::XCOFFObjectFile>(**OptionalObject))
return object::Archive::K_AIXBIG;
if (isa<object::COFFObjectFile>(**OptionalObject) ||
isa<object::COFFImportFile>(**OptionalObject))
return object::Archive::K_COFF;
if (isa<object::GOFFObjectFile>(**OptionalObject))
return object::Archive::K_ZOS;
return object::Archive::K_GNU;
}
// Squelch the error in case we had a non-object file.
consumeError(OptionalObject.takeError());
// If we're adding a bitcode file to the archive, detect the Archive kind
// based on the target triple.
LLVMContext Context;
if (identify_magic(MemBufferRef.getBuffer()) == file_magic::bitcode) {
if (auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
MemBufferRef, file_magic::bitcode, &Context)) {
auto &IRObject = cast<object::IRObjectFile>(**ObjOrErr);
auto TargetTriple = Triple(IRObject.getTargetTriple());
return object::Archive::getDefaultKindForTriple(TargetTriple);
} else {
// Squelch the error in case this was not a SymbolicFile.
consumeError(ObjOrErr.takeError());
}
}
return object::Archive::getDefaultKind();
}
Expected<NewArchiveMember>
NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
bool Deterministic) {
Expected<llvm::MemoryBufferRef> BufOrErr = OldMember.getMemoryBufferRef();
if (!BufOrErr)
return BufOrErr.takeError();
NewArchiveMember M;
M.Buf = MemoryBuffer::getMemBuffer(*BufOrErr, false);
M.MemberName = M.Buf->getBufferIdentifier();
if (!Deterministic) {
auto ModTimeOrErr = OldMember.getLastModified();
if (!ModTimeOrErr)
return ModTimeOrErr.takeError();
M.ModTime = ModTimeOrErr.get();
Expected<unsigned> UIDOrErr = OldMember.getUID();
if (!UIDOrErr)
return UIDOrErr.takeError();
M.UID = UIDOrErr.get();
Expected<unsigned> GIDOrErr = OldMember.getGID();
if (!GIDOrErr)
return GIDOrErr.takeError();
M.GID = GIDOrErr.get();
Expected<sys::fs::perms> AccessModeOrErr = OldMember.getAccessMode();
if (!AccessModeOrErr)
return AccessModeOrErr.takeError();
M.Perms = AccessModeOrErr.get();
}
return std::move(M);
}
Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
bool Deterministic) {
sys::fs::file_status Status;
auto FDOrErr = sys::fs::openNativeFileForRead(FileName);
if (!FDOrErr)
return FDOrErr.takeError();
sys::fs::file_t FD = *FDOrErr;
assert(FD.isValid());
if (auto EC = sys::fs::status(FD, Status))
return errorCodeToError(EC);
// Opening a directory doesn't make sense. Let it fail.
// Linux cannot open directories with open(2), although
// cygwin and *bsd can.
if (Status.type() == sys::fs::file_type::directory_file)
return errorCodeToError(make_error_code(errc::is_a_directory));
ErrorOr<std::unique_ptr<MemoryBuffer>> MemberBufferOrErr =
MemoryBuffer::getOpenFile(FD, FileName, Status.getSize(), false);
if (!MemberBufferOrErr)
return errorCodeToError(MemberBufferOrErr.getError());
if (auto EC = sys::fs::closeFile(FD))
return errorCodeToError(EC);
NewArchiveMember M;
M.Buf = std::move(*MemberBufferOrErr);
M.MemberName = M.Buf->getBufferIdentifier();
if (!Deterministic) {
M.ModTime = std::chrono::time_point_cast<std::chrono::seconds>(
Status.getLastModificationTime());
M.UID = Status.getUser();
M.GID = Status.getGroup();
M.Perms = Status.permissions();
}
return std::move(M);
}
template <typename T>
static void printWithSpacePadding(raw_ostream &OS, T Data, unsigned Size) {
uint64_t OldPos = OS.tell();
OS << Data;
unsigned SizeSoFar = OS.tell() - OldPos;
assert(SizeSoFar <= Size && "Data doesn't fit in Size");
OS.indent(Size - SizeSoFar);
}
static bool isDarwin(object::Archive::Kind Kind) {
return Kind == object::Archive::K_DARWIN ||
Kind == object::Archive::K_DARWIN64;
}
static bool isAIXBigArchive(object::Archive::Kind Kind) {
return Kind == object::Archive::K_AIXBIG;
}
static bool isCOFFArchive(object::Archive::Kind Kind) {
return Kind == object::Archive::K_COFF;
}
static bool isZOSArchive(object::Archive::Kind Kind) {
return Kind == object::Archive::K_ZOS;
}
static bool isBSDLike(object::Archive::Kind Kind) {
switch (Kind) {
case object::Archive::K_GNU:
case object::Archive::K_GNU64:
case object::Archive::K_AIXBIG:
case object::Archive::K_COFF:
case object::Archive::K_ZOS:
return false;
case object::Archive::K_BSD:
case object::Archive::K_DARWIN:
case object::Archive::K_DARWIN64:
return true;
}
llvm_unreachable("not supported for writting");
}
template <class T>
static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val) {
support::endian::write(Out, Val,
isBSDLike(Kind) ? llvm::endianness::little
: llvm::endianness::big);
}
template <class T> static void printLE(raw_ostream &Out, T Val) {
support::endian::write(Out, Val, llvm::endianness::little);
}
static void printRestOfMemberHeader(
raw_ostream &Out, const sys::TimePoint<std::chrono::seconds> &ModTime,
unsigned UID, unsigned GID, unsigned Perms, uint64_t Size) {
printWithSpacePadding(Out, sys::toTimeT(ModTime), 12);
// The format has only 6 chars for uid and gid. Truncate if the provided
// values don't fit.
printWithSpacePadding(Out, UID % 1000000, 6);
printWithSpacePadding(Out, GID % 1000000, 6);
printWithSpacePadding(Out, format("%o", Perms), 8);
printWithSpacePadding(Out, Size, 10);
Out << "`\n";
}
static void
printGNUSmallMemberHeader(raw_ostream &Out, StringRef Name,
const sys::TimePoint<std::chrono::seconds> &ModTime,
unsigned UID, unsigned GID, unsigned Perms,
uint64_t Size) {
printWithSpacePadding(Out, Twine(Name) + "/", 16);
printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
}
static void
printBSDMemberHeader(raw_ostream &Out, uint64_t Pos, StringRef Name,
const sys::TimePoint<std::chrono::seconds> &ModTime,
unsigned UID, unsigned GID, unsigned Perms, uint64_t Size) {
uint64_t PosAfterHeader = Pos + 60 + Name.size();
// Pad so that even 64 bit object files are aligned.
unsigned Pad = offsetToAlignment(PosAfterHeader, Align(8));
unsigned NameWithPadding = Name.size() + Pad;
printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
NameWithPadding + Size);
Out << Name;
while (Pad--)
Out.write(uint8_t(0));
}
static void
printZOSMemberHeader(raw_ostream &Out, StringRef Name,
const sys::TimePoint<std::chrono::seconds> &ModTime,
unsigned UID, unsigned GID, unsigned Perms,
uint64_t Size) {
std::string AHeader;
raw_string_ostream AOut(AHeader);
if (Name.size() <= 16) {
printWithSpacePadding(AOut, Twine(Name), 16);
printRestOfMemberHeader(AOut, ModTime, UID, GID, Perms, Size);
} else {
// z/OS ar stores the exact name length inline with no extra alignment
// padding, unlike the BSD format which pads to an 8-byte boundary.
printWithSpacePadding(AOut, Twine("#1/") + Twine(Name.size()), 16);
printRestOfMemberHeader(AOut, ModTime, UID, GID, Perms, Name.size() + Size);
AOut << Name;
}
SmallString<256> EHeader;
if (std::error_code EC = ConverterEBCDIC::convertToEBCDIC(AHeader, EHeader))
report_fatal_error(
Twine("failed to convert z/OS member header to EBCDIC: ") +
EC.message());
Out << EHeader.str();
}
static void
printBigArchiveMemberHeader(raw_ostream &Out, StringRef Name,
const sys::TimePoint<std::chrono::seconds> &ModTime,
unsigned UID, unsigned GID, unsigned Perms,
uint64_t Size, uint64_t PrevOffset,
uint64_t NextOffset) {
unsigned NameLen = Name.size();
printWithSpacePadding(Out, Size, 20); // File member size
printWithSpacePadding(Out, NextOffset, 20); // Next member header offset
printWithSpacePadding(Out, PrevOffset, 20); // Previous member header offset
printWithSpacePadding(Out, sys::toTimeT(ModTime), 12); // File member date
// The big archive format has 12 chars for uid and gid.
printWithSpacePadding(Out, UID % 1000000000000, 12); // UID
printWithSpacePadding(Out, GID % 1000000000000, 12); // GID
printWithSpacePadding(Out, format("%o", Perms), 12); // Permission
printWithSpacePadding(Out, NameLen, 4); // Name length
if (NameLen) {
printWithSpacePadding(Out, Name, NameLen); // Name
if (NameLen % 2)
Out.write(uint8_t(0)); // Null byte padding
}
Out << "`\n"; // Terminator
}
static bool useStringTable(bool Thin, StringRef Name) {
return Thin || Name.size() >= 16 || Name.contains('/');
}
static bool is64BitKind(object::Archive::Kind Kind) {
switch (Kind) {
case object::Archive::K_GNU:
case object::Archive::K_BSD:
case object::Archive::K_DARWIN:
case object::Archive::K_COFF:
case object::Archive::K_ZOS:
return false;
case object::Archive::K_AIXBIG:
case object::Archive::K_DARWIN64:
case object::Archive::K_GNU64:
return true;
}
llvm_unreachable("not supported for writting");
}
static void
printMemberHeader(raw_ostream &Out, uint64_t Pos, raw_ostream &StringTable,
StringMap<uint64_t> &MemberNames, object::Archive::Kind Kind,
bool Thin, const NewArchiveMember &M, StringRef MemberName,
sys::TimePoint<std::chrono::seconds> ModTime, uint64_t Size) {
if (isBSDLike(Kind))
return printBSDMemberHeader(Out, Pos, MemberName, ModTime, M.UID, M.GID,
M.Perms, Size);
if (isZOSArchive(Kind))
return printZOSMemberHeader(Out, MemberName, ModTime, M.UID, M.GID, M.Perms,
Size);
if (!useStringTable(Thin, MemberName))
return printGNUSmallMemberHeader(Out, MemberName, ModTime, M.UID, M.GID,
M.Perms, Size);
Out << '/';
uint64_t NamePos;
if (Thin) {
NamePos = StringTable.tell();
StringTable << MemberName << "/\n";
} else {
auto Insertion = MemberNames.insert({MemberName, uint64_t(0)});
if (Insertion.second) {
Insertion.first->second = StringTable.tell();
StringTable << MemberName;
if (isCOFFArchive(Kind))
StringTable << '\0';
else
StringTable << "/\n";
}
NamePos = Insertion.first->second;
}
printWithSpacePadding(Out, NamePos, 15);
printRestOfMemberHeader(Out, ModTime, M.UID, M.GID, M.Perms, Size);
}
namespace {
struct MemberData {
std::vector<unsigned> Symbols;
// z/OS archive attribute bits per symbol. Entry i of SymbolAttrs corresponds
// to Symbols[i]. These attributes are empty for non-z/OS archives.
std::vector<uint32_t> SymbolAttrs;
std::string Header;
StringRef Data;
StringRef Padding;
uint64_t PreHeadPadSize = 0;
std::unique_ptr<SymbolicFile> SymFile = nullptr;
std::string HybridName = "";
std::unique_ptr<MemoryBuffer> NativeBuf = nullptr;
};
} // namespace
static MemberData computeStringTable(StringRef Names) {
unsigned Size = Names.size();
unsigned Pad = offsetToAlignment(Size, Align(2));
std::string Header;
raw_string_ostream Out(Header);
printWithSpacePadding(Out, "//", 48);
printWithSpacePadding(Out, Size + Pad, 10);
Out << "`\n";
return {{}, {}, std::move(Header), Names, Pad ? "\n" : ""};
}
static sys::TimePoint<std::chrono::seconds> now(bool Deterministic) {
using namespace std::chrono;
if (!Deterministic)
return time_point_cast<seconds>(system_clock::now());
return sys::TimePoint<seconds>();
}
static bool isArchiveSymbol(const object::BasicSymbolRef &S) {
Expected<uint32_t> SymFlagsOrErr = S.getFlags();
if (!SymFlagsOrErr)
// TODO: Actually report errors helpfully.
report_fatal_error(SymFlagsOrErr.takeError());
if (*SymFlagsOrErr & object::SymbolRef::SF_FormatSpecific)
return false;
if (!(*SymFlagsOrErr & object::SymbolRef::SF_Global))
return false;
if (*SymFlagsOrErr & object::SymbolRef::SF_Undefined)
return false;
return true;
}
static void printNBits(raw_ostream &Out, object::Archive::Kind Kind,
uint64_t Val) {
if (is64BitKind(Kind))
print<uint64_t>(Out, Kind, Val);
else
print<uint32_t>(Out, Kind, Val);
}
static uint64_t computeSymbolTableSize(object::Archive::Kind Kind,
uint64_t NumSyms, uint64_t OffsetSize,
uint64_t StringTableSize,
uint32_t *Padding = nullptr) {
assert((OffsetSize == 4 || OffsetSize == 8) && "Unsupported OffsetSize");
uint64_t Size = OffsetSize; // Number of entries
// Each symbol table entry consists of a member offset.
// For BSD, each entry also includes a string table offset.
// For z/OS, each entry instead also includes a flag field.
if (isBSDLike(Kind) || isZOSArchive(Kind))
Size += NumSyms * OffsetSize * 2; // Table
else
Size += NumSyms * OffsetSize; // Table
if (isBSDLike(Kind))
Size += OffsetSize; // byte count
Size += StringTableSize;
// ld64 expects the members to be 8-byte aligned for 64-bit content and at
// least 4-byte aligned for 32-bit content. Opt for the larger encoding
// uniformly.
// We do this for all bsd formats because it simplifies aligning members.
// For the big archive format, the symbol table is the last member, so there
// is no need to align.
uint32_t Pad = isAIXBigArchive(Kind)
? 0
: offsetToAlignment(Size, Align(isBSDLike(Kind) ? 8 : 2));
Size += Pad;
if (Padding)
*Padding = Pad;
return Size;
}
static uint64_t computeSymbolMapSize(uint64_t NumObj, SymMap &SymMap,
uint32_t *Padding = nullptr) {
uint64_t Size = sizeof(uint32_t) * 2; // Number of symbols and objects entries
Size += NumObj * sizeof(uint32_t); // Offset table
for (auto S : SymMap.Map)
Size += sizeof(uint16_t) + S.first.length() + 1;
uint32_t Pad = offsetToAlignment(Size, Align(2));
Size += Pad;
if (Padding)
*Padding = Pad;
return Size;
}
static uint64_t computeECSymbolsSize(SymMap &SymMap,
uint32_t *Padding = nullptr) {
uint64_t Size = sizeof(uint32_t); // Number of symbols
for (auto S : SymMap.ECMap)
Size += sizeof(uint16_t) + S.first.length() + 1;
uint32_t Pad = offsetToAlignment(Size, Align(2));
Size += Pad;
if (Padding)
*Padding = Pad;
return Size;
}
static void writeSymbolTableHeader(raw_ostream &Out, object::Archive::Kind Kind,
bool Deterministic, uint64_t Size,
uint64_t PrevMemberOffset = 0,
uint64_t NextMemberOffset = 0) {
if (isBSDLike(Kind)) {
const char *Name = is64BitKind(Kind) ? "__.SYMDEF_64" : "__.SYMDEF";
printBSDMemberHeader(Out, Out.tell(), Name, now(Deterministic), 0, 0, 0,
Size);
} else if (isAIXBigArchive(Kind)) {
printBigArchiveMemberHeader(Out, "", now(Deterministic), 0, 0, 0, Size,
PrevMemberOffset, NextMemberOffset);
} else if (isZOSArchive(Kind)) {
const char *Name = "__.SYMDEF";
printZOSMemberHeader(Out, Name, now(Deterministic), 0, 0, 0, Size);
} else {
const char *Name = is64BitKind(Kind) ? "/SYM64" : "";
printGNUSmallMemberHeader(Out, Name, now(Deterministic), 0, 0, 0, Size);
}
}
static uint64_t computeHeadersSize(object::Archive::Kind Kind,
uint64_t NumMembers,
uint64_t StringMemberSize, uint64_t NumSyms,
uint64_t SymNamesSize, SymMap *SymMap) {
uint32_t OffsetSize = is64BitKind(Kind) ? 8 : 4;
uint64_t SymtabSize =
computeSymbolTableSize(Kind, NumSyms, OffsetSize, SymNamesSize);
auto computeSymbolTableHeaderSize = [=] {
SmallString<0> TmpBuf;
raw_svector_ostream Tmp(TmpBuf);
writeSymbolTableHeader(Tmp, Kind, true, SymtabSize);
return TmpBuf.size();
};
uint32_t HeaderSize = computeSymbolTableHeaderSize();
uint64_t Size = strlen("!<arch>\n") + HeaderSize + SymtabSize;
if (SymMap) {
Size += HeaderSize + computeSymbolMapSize(NumMembers, *SymMap);
if (SymMap->ECMap.size())
Size += HeaderSize + computeECSymbolsSize(*SymMap);
}
return Size + StringMemberSize;
}
static Expected<std::unique_ptr<SymbolicFile>>
getSymbolicFile(MemoryBufferRef Buf, LLVMContext &Context,
object::Archive::Kind Kind, function_ref<void(Error)> Warn) {
const file_magic Type = identify_magic(Buf.getBuffer());
// Don't attempt to read non-symbolic file types.
if (!object::SymbolicFile::isSymbolicFile(Type, &Context))
return nullptr;
if (Type == file_magic::bitcode) {
auto ObjOrErr = object::SymbolicFile::createSymbolicFile(
Buf, file_magic::bitcode, &Context);
// An error reading a bitcode file most likely indicates that the file
// was created by a compiler from the future. Normally we don't try to
// implement forwards compatibility for bitcode files, but when creating an
// archive we can implement best-effort forwards compatibility by treating
// the file as a blob and not creating symbol index entries for it. lld and
// mold ignore the archive symbol index, so provided that you use one of
// these linkers, LTO will work as long as lld or the gold plugin is newer
// than the compiler. We only ignore errors if the archive format is one
// that is supported by a linker that is known to ignore the index,
// otherwise there's no chance of this working so we may as well error out.
// We print a warning on read failure so that users of linkers that rely on
// the symbol index can diagnose the issue.
//
// This is the same behavior as GNU ar when the linker plugin returns an
// error when reading the input file. If the bitcode file is actually
// malformed, it will be diagnosed at link time.
if (!ObjOrErr) {
switch (Kind) {
case object::Archive::K_BSD:
case object::Archive::K_GNU:
case object::Archive::K_GNU64:
Warn(ObjOrErr.takeError());
return nullptr;
case object::Archive::K_AIXBIG:
case object::Archive::K_COFF:
case object::Archive::K_DARWIN:
case object::Archive::K_DARWIN64:
case object::Archive::K_ZOS:
return ObjOrErr.takeError();
}
}
return std::move(*ObjOrErr);
} else {
auto ObjOrErr = object::SymbolicFile::createSymbolicFile(Buf);
if (!ObjOrErr)
return ObjOrErr.takeError();
return std::move(*ObjOrErr);
}
}
static bool is64BitSymbolicFile(const SymbolicFile *SymObj) {
return SymObj != nullptr ? SymObj->is64Bit() : false;
}
// Log2 of PAGESIZE(4096) on an AIX system.
static const uint32_t Log2OfAIXPageSize = 12;
// In the AIX big archive format, since the data content follows the member file
// name, if the name ends on an odd byte, an extra byte will be added for
// padding. This ensures that the data within the member file starts at an even
// byte.
static const uint32_t MinBigArchiveMemDataAlign = 2;
template <typename AuxiliaryHeader>
uint16_t getAuxMaxAlignment(uint16_t AuxHeaderSize, AuxiliaryHeader *AuxHeader,
uint16_t Log2OfMaxAlign) {
// If the member doesn't have an auxiliary header, it isn't a loadable object
// and so it just needs aligning at the minimum value.
if (AuxHeader == nullptr)
return MinBigArchiveMemDataAlign;
// If the auxiliary header does not have both MaxAlignOfData and
// MaxAlignOfText field, it is not a loadable shared object file, so align at
// the minimum value. The 'ModuleType' member is located right after
// 'MaxAlignOfData' in the AuxiliaryHeader.
if (AuxHeaderSize < offsetof(AuxiliaryHeader, ModuleType))
return MinBigArchiveMemDataAlign;
// If the XCOFF object file does not have a loader section, it is not
// loadable, so align at the minimum value.
if (AuxHeader->SecNumOfLoader == 0)
return MinBigArchiveMemDataAlign;
// The content of the loadable member file needs to be aligned at MAX(maximum
// alignment of .text, maximum alignment of .data) if there are both fields.
// If the desired alignment is > PAGESIZE, 32-bit members are aligned on a
// word boundary, while 64-bit members are aligned on a PAGESIZE(2^12=4096)
// boundary.
uint16_t Log2OfAlign =
std::max(AuxHeader->MaxAlignOfText, AuxHeader->MaxAlignOfData);
return 1 << (Log2OfAlign > Log2OfAIXPageSize ? Log2OfMaxAlign : Log2OfAlign);
}
// AIX big archives may contain shared object members. The AIX OS requires these
// members to be aligned if they are 64-bit and recommends it for 32-bit
// members. This ensures that when these members are loaded they are aligned in
// memory.
static uint32_t getMemberAlignment(SymbolicFile *SymObj) {
XCOFFObjectFile *XCOFFObj = dyn_cast_or_null<XCOFFObjectFile>(SymObj);
if (!XCOFFObj)
return MinBigArchiveMemDataAlign;
// If the desired alignment is > PAGESIZE, 32-bit members are aligned on a
// word boundary, while 64-bit members are aligned on a PAGESIZE boundary.
return XCOFFObj->is64Bit()
? getAuxMaxAlignment(XCOFFObj->fileHeader64()->AuxHeaderSize,
XCOFFObj->auxiliaryHeader64(),
Log2OfAIXPageSize)
: getAuxMaxAlignment(XCOFFObj->fileHeader32()->AuxHeaderSize,
XCOFFObj->auxiliaryHeader32(), 2);
}
static void writeSymbolTable(raw_ostream &Out, object::Archive::Kind Kind,
bool Deterministic, ArrayRef<MemberData> Members,
StringRef StringTable, uint64_t MembersOffset,
unsigned NumSyms, uint64_t PrevMemberOffset = 0,
uint64_t NextMemberOffset = 0,
bool Is64Bit = false) {
// We don't write a symbol table on an archive with no members -- except on
// Darwin, where the linker will abort unless the archive has a symbol table.
if (StringTable.empty() && !isDarwin(Kind) && !isCOFFArchive(Kind))
return;
uint64_t OffsetSize = is64BitKind(Kind) ? 8 : 4;
uint32_t Pad;
uint64_t Size = computeSymbolTableSize(Kind, NumSyms, OffsetSize,
StringTable.size(), &Pad);
// Padding size is not included in the Size field of the z/OS symbol table
// header.
int64_t HeaderSize = Size;
if (isZOSArchive(Kind))
HeaderSize -= Pad;
writeSymbolTableHeader(Out, Kind, Deterministic, HeaderSize, PrevMemberOffset,
NextMemberOffset);
if (isBSDLike(Kind))
printNBits(Out, Kind, NumSyms * 2 * OffsetSize);
else
printNBits(Out, Kind, NumSyms);
uint64_t Pos = MembersOffset;
for (const MemberData &M : Members) {
if (isAIXBigArchive(Kind)) {
Pos += M.PreHeadPadSize;
if (is64BitSymbolicFile(M.SymFile.get()) != Is64Bit) {
Pos += M.Header.size() + M.Data.size() + M.Padding.size();
continue;
}
}
assert((!isZOSArchive(Kind) || M.Symbols.size() == M.SymbolAttrs.size()) &&
"Incorrect number of symbol attributes!");
for (size_t I = 0, E = M.Symbols.size(); I != E; ++I) {
if (isBSDLike(Kind))
printNBits(Out, Kind, M.Symbols[I]);
printNBits(Out, Kind, Pos); // member offset
if (isZOSArchive(Kind))
printNBits(Out, Kind, M.SymbolAttrs[I]); // symbol attributes
}
Pos += M.Header.size() + M.Data.size() + M.Padding.size();
}
if (isBSDLike(Kind))
// byte count of the string table
printNBits(Out, Kind, StringTable.size());
if (isZOSArchive(Kind)) {
SmallString<256> EStringTable;
if (std::error_code EC =
ConverterEBCDIC::convertToEBCDIC(StringTable, EStringTable))
report_fatal_error(
Twine("failed to convert z/OS symbol table to EBCDIC: ") +
EC.message());
Out << EStringTable.str();
} else {
Out << StringTable;
}
while (Pad--)
Out.write(uint8_t(0));
}
static void writeSymbolMap(raw_ostream &Out, object::Archive::Kind Kind,
bool Deterministic, ArrayRef<MemberData> Members,
SymMap &SymMap, uint64_t MembersOffset) {
uint32_t Pad;
uint64_t Size = computeSymbolMapSize(Members.size(), SymMap, &Pad);
writeSymbolTableHeader(Out, Kind, Deterministic, Size, 0);
uint32_t Pos = MembersOffset;
printLE<uint32_t>(Out, Members.size());
for (const MemberData &M : Members) {
printLE(Out, Pos); // member offset
Pos += M.Header.size() + M.Data.size() + M.Padding.size();
}
printLE<uint32_t>(Out, SymMap.Map.size());
for (auto S : SymMap.Map)
printLE(Out, S.second);
for (auto S : SymMap.Map)
Out << S.first << '\0';
while (Pad--)
Out.write(uint8_t(0));
}
static void writeECSymbols(raw_ostream &Out, object::Archive::Kind Kind,
bool Deterministic, ArrayRef<MemberData> Members,
SymMap &SymMap) {
uint32_t Pad;
uint64_t Size = computeECSymbolsSize(SymMap, &Pad);
printGNUSmallMemberHeader(Out, "/<ECSYMBOLS>", now(Deterministic), 0, 0, 0,
Size);
printLE<uint32_t>(Out, SymMap.ECMap.size());
for (auto S : SymMap.ECMap)
printLE(Out, S.second);
for (auto S : SymMap.ECMap)
Out << S.first << '\0';
while (Pad--)
Out.write(uint8_t(0));
}
static bool isECObject(object::SymbolicFile &Obj) {
if (Obj.isCOFF())
return cast<llvm::object::COFFObjectFile>(&Obj)->getMachine() !=
COFF::IMAGE_FILE_MACHINE_ARM64;
if (Obj.isCOFFImportFile())
return cast<llvm::object::COFFImportFile>(&Obj)->getMachine() !=
COFF::IMAGE_FILE_MACHINE_ARM64;
if (Obj.isIR()) {
Expected<std::string> TripleStr =
getBitcodeTargetTriple(Obj.getMemoryBufferRef());
if (!TripleStr)
return false;
Triple T(std::move(*TripleStr));
return T.isWindowsArm64EC() || T.getArch() == Triple::x86_64;
}
return false;
}
static bool isAnyArm64COFF(object::SymbolicFile &Obj) {
if (Obj.isCOFF())
return COFF::isAnyArm64(cast<COFFObjectFile>(&Obj)->getMachine());
if (Obj.isCOFFImportFile())
return COFF::isAnyArm64(cast<COFFImportFile>(&Obj)->getMachine());
if (Obj.isIR()) {
Expected<std::string> TripleStr =
getBitcodeTargetTriple(Obj.getMemoryBufferRef());
if (!TripleStr)
return false;
Triple T(std::move(*TripleStr));
return T.isOSWindows() && T.getArch() == Triple::aarch64;
}
return false;
}
bool isImportDescriptor(StringRef Name) {
return Name.starts_with(ImportDescriptorPrefix) ||
Name == StringRef{NullImportDescriptorSymbolName} ||
(Name.starts_with(NullThunkDataPrefix) &&
Name.ends_with(NullThunkDataSuffix));
}
static Expected<std::vector<unsigned>> getSymbols(SymbolicFile *Obj,
uint16_t Index,
raw_ostream &SymNames,
SymMap *SymMap) {
std::vector<unsigned> Ret;
if (Obj == nullptr)
return Ret;
std::map<std::string, uint16_t> *Map = nullptr;
if (SymMap)
Map = SymMap->UseECMap && isECObject(*Obj) ? &SymMap->ECMap : &SymMap->Map;
for (const object::BasicSymbolRef &S : Obj->symbols()) {
if (!isArchiveSymbol(S))
continue;
if (Map) {
std::string Name;
raw_string_ostream NameStream(Name);
if (Error E = S.printName(NameStream))
return std::move(E);
if (!Map->try_emplace(Name, Index).second)
continue; // ignore duplicated symbol
if (Map == &SymMap->Map) {
Ret.push_back(SymNames.tell());
SymNames << Name << '\0';
// If EC is enabled, then the import descriptors are NOT put into EC
// objects so we need to copy them to the EC map manually.
if (SymMap->UseECMap && isImportDescriptor(Name))
SymMap->ECMap[Name] = Index;
}
} else {
Ret.push_back(SymNames.tell());
if (Error E = S.printName(SymNames))
return std::move(E);
SymNames << '\0';
}
}
return Ret;
}
static Expected<std::vector<MemberData>>
computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
object::Archive::Kind Kind, bool Thin, bool Deterministic,
SymtabWritingMode NeedSymbols, SymMap *SymMap,
LLVMContext &Context, ArrayRef<NewArchiveMember> NewMembers,
std::optional<bool> IsEC, function_ref<void(Error)> Warn) {
static char PaddingData[8] = {'\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n'};
static char ZOSPaddingData[8] = {0x15, 0x15, 0x15, 0x15,
0x15, 0x15, 0x15, 0x15}; // EBCDIC newlines.
uint64_t Pos =
isAIXBigArchive(Kind) ? sizeof(object::BigArchive::FixLenHdr) : 0;
std::vector<MemberData> Ret;
bool HasObject = false;
// Deduplicate long member names in the string table and reuse earlier name
// offsets. This especially saves space for COFF Import libraries where all
// members have the same name.
StringMap<uint64_t> MemberNames;
// UniqueTimestamps is a special case to improve debugging on Darwin:
//
// The Darwin linker does not link debug info into the final
// binary. Instead, it emits entries of type N_OSO in the output
// binary's symbol table, containing references to the linked-in
// object files. Using that reference, the debugger can read the
// debug data directly from the object files. Alternatively, an
// invocation of 'dsymutil' will link the debug data from the object
// files into a dSYM bundle, which can be loaded by the debugger,
// instead of the object files.
//
// For an object file, the N_OSO entries contain the absolute path
// path to the file, and the file's timestamp. For an object
// included in an archive, the path is formatted like
// "/absolute/path/to/archive.a(member.o)", and the timestamp is the
// archive member's timestamp, rather than the archive's timestamp.
//
// However, this doesn't always uniquely identify an object within
// an archive -- an archive file can have multiple entries with the
// same filename. (This will happen commonly if the original object
// files started in different directories.) The only way they get
// distinguished, then, is via the timestamp. But this process is
// unable to find the correct object file in the archive when there
// are two files of the same name and timestamp.
//
// Additionally, timestamp==0 is treated specially, and causes the
// timestamp to be ignored as a match criteria.
//
// That will "usually" work out okay when creating an archive not in
// deterministic timestamp mode, because the objects will probably
// have been created at different timestamps.
//
// To ameliorate this problem, in deterministic archive mode (which
// is the default), on Darwin we will emit a unique non-zero
// timestamp for each entry with a duplicated name. This is still
// deterministic: the only thing affecting that timestamp is the
// order of the files in the resultant archive.
//
// See also the functions that handle the lookup:
// in lldb: ObjectContainerBSDArchive::Archive::FindObject()
// in llvm/tools/dsymutil: BinaryHolder::GetArchiveMemberBuffers().
bool UniqueTimestamps = Deterministic && isDarwin(Kind);
std::map<StringRef, unsigned> FilenameCount;
if (UniqueTimestamps) {
for (const NewArchiveMember &M : NewMembers)
FilenameCount[M.MemberName]++;
for (auto &Entry : FilenameCount)
Entry.second = Entry.second > 1 ? 1 : 0;
}
uint32_t LastZosObjIndex =
UINT_MAX; // Only set when writing symbol table in z/OS archive.
for (const NewArchiveMember &M : NewMembers) {
MemberData &D = Ret.emplace_back();
D.Data = M.Buf->getBuffer();
if (NeedSymbols != SymtabWritingMode::NoSymtab || isAIXBigArchive(Kind)) {
Expected<std::unique_ptr<SymbolicFile>> SymFileOrErr = getSymbolicFile(
M.Buf->getMemBufferRef(), Context, Kind, [&](Error Err) {
Warn(createFileError(M.MemberName, std::move(Err)));
});
if (!SymFileOrErr)
return createFileError(M.MemberName, SymFileOrErr.takeError());
D.SymFile = std::move(*SymFileOrErr);
if (SymMap && D.SymFile.get()) {
auto COFFObj = dyn_cast<COFFObjectFile>(D.SymFile.get());
std::optional<MemoryBufferRef> HybridView;
if (COFFObj && (HybridView = COFFObj->findHybridObjectSection())) {
// Strip the hybrid section.
D.NativeBuf = COFFObj->stripHybridSection();
D.Data = D.NativeBuf->getBuffer();
// Create a separate archive member for the hybrid ARM64X object.
MemberData &ECData = Ret.emplace_back();
ECData.Data = HybridView->getBuffer();
SymFileOrErr =
getSymbolicFile(*HybridView, Context, Kind, [&](Error Err) {
Warn(createFileError(M.MemberName, std::move(Err)));
});
if (!SymFileOrErr)
return createFileError(M.MemberName, SymFileOrErr.takeError());
ECData.SymFile = std::move(*SymFileOrErr);
// Use obj.arm64ec subdirectory for the hybrid object name.
size_t Pos = M.MemberName.find_last_of("/\\");
Pos = Pos == StringRef::npos ? 0 : Pos + 1;
ECData.HybridName = (M.MemberName.substr(0, Pos) + "obj.arm64ec/" +
M.MemberName.substr(Pos))
.str();
}
}
if (isZOSArchive(Kind) && D.SymFile.get())
LastZosObjIndex = Ret.size() - 1;
}
}
if (SymMap) {
if (IsEC) {
SymMap->UseECMap = *IsEC;
} else {
// When IsEC is not specified by the caller, use it when we have both
// any ARM64 object (ARM64 or ARM64EC) and any EC object (ARM64EC or
// AMD64). This may be a single ARM64EC object, but may also be separate
// ARM64 and AMD64 objects.
bool HaveArm64 = false, HaveEC = false;
for (const MemberData &D : Ret) {
if (!D.SymFile)
continue;
if (!HaveArm64)
HaveArm64 = isAnyArm64COFF(*D.SymFile);
if (!HaveEC)
HaveEC = isECObject(*D.SymFile);
if (HaveArm64 && HaveEC) {
SymMap->UseECMap = true;
break;
}
}
}
}
// The big archive format needs to know the offset of the previous member
// header.
uint64_t PrevOffset = 0;
uint64_t NextMemHeadPadSize = 0;
for (uint32_t Index = 0, MemberIndex = 0; Index < Ret.size(); ++Index) {
MemberData &D = Ret[Index];
const NewArchiveMember *M = &NewMembers[MemberIndex];
// Native COFF members (resulting from stripping a hybrid object section)
// are followed by an extracted hybrid object member, using the same
// NewArchiveMember.
if (!D.NativeBuf.get())
++MemberIndex;
raw_string_ostream Out(D.Header);
uint64_t Size = D.Data.size();
if (Thin)
D.Data = "";
// ld64 expects the members to be 8-byte aligned for 64-bit content and at
// least 4-byte aligned for 32-bit content. Opt for the larger encoding
// uniformly. This matches the behaviour with cctools and ensures that ld64
// is happy with archives that we generate.
unsigned MemberPadding =
isDarwin(Kind) ? offsetToAlignment(D.Data.size(), Align(8)) : 0;
StringRef MemberName = D.HybridName.size() ? D.HybridName : M->MemberName;
// z/OS stores long member names inline using their exact byte length.
// Include the inline name when computing alignment.
uint64_t PaddingBase = D.Data.size() + MemberPadding;
if (isZOSArchive(Kind) && MemberName.size() > 16)
PaddingBase += MemberName.size();
unsigned TailPadding = offsetToAlignment(PaddingBase, Align(2));
D.Padding = StringRef(isZOSArchive(Kind) ? ZOSPaddingData : PaddingData,
MemberPadding + TailPadding);
sys::TimePoint<std::chrono::seconds> ModTime;
if (UniqueTimestamps)
// Increment timestamp for each file of a given name.
ModTime = sys::toTimePoint(FilenameCount[MemberName]++);
else
ModTime = M->ModTime;
Size += MemberPadding;
if (Size > object::Archive::MaxMemberSize) {
std::string StringMsg =
"File " + MemberName.str() + " exceeds size limit";
return make_error<object::GenericBinaryError>(
std::move(StringMsg), object::object_error::parse_failed);
}
// In the big archive file format, we need to calculate and include the next
// member offset and previous member offset in the file member header.
if (isAIXBigArchive(Kind)) {
uint64_t OffsetToMemData =
Pos + sizeof(object::BigArMemHdrType) + alignTo(MemberName.size(), 2);
if (Index == 0)
NextMemHeadPadSize =
alignToPowerOf2(OffsetToMemData,
getMemberAlignment(D.SymFile.get())) -
OffsetToMemData;
D.PreHeadPadSize = NextMemHeadPadSize;
Pos += D.PreHeadPadSize;
uint64_t NextOffset = Pos + sizeof(object::BigArMemHdrType) +
alignTo(MemberName.size(), 2) + alignTo(Size, 2);
// If there is another member file after this, we need to calculate the
// padding before the header.
if (Index + 1 != Ret.size()) {
uint64_t OffsetToNextMemData =
NextOffset + sizeof(object::BigArMemHdrType) +
alignTo(NewMembers[MemberIndex].MemberName.size(), 2);
NextMemHeadPadSize =
alignToPowerOf2(OffsetToNextMemData,
getMemberAlignment(Ret[Index + 1].SymFile.get())) -
OffsetToNextMemData;
NextOffset += NextMemHeadPadSize;
}
printBigArchiveMemberHeader(Out, MemberName, ModTime, M->UID, M->GID,
M->Perms, Size, PrevOffset, NextOffset);
PrevOffset = Pos;
} else {
printMemberHeader(Out, Pos, StringTable, MemberNames, Kind, Thin, *M,
MemberName, ModTime, Size);
}
if (NeedSymbols != SymtabWritingMode::NoSymtab) {
Expected<std::vector<unsigned>> SymbolsOrErr =
getSymbols(D.SymFile.get(), Index + 1, SymNames, SymMap);
if (!SymbolsOrErr)
return createFileError(MemberName, SymbolsOrErr.takeError());
D.Symbols = std::move(*SymbolsOrErr);
// For z/OS, populate SymbolAttrs in lockstep with Symbols so that
// writeSymbolTable() can emit the per-symbol attribute word.
if (isZOSArchive(Kind)) {
auto *GOFFObj = dyn_cast_or_null<GOFFObjectFile>(D.SymFile.get());
if (GOFFObj) {
for (object::BasicSymbolRef S : GOFFObj->symbols()) {
if (!isArchiveSymbol(S))
continue;
D.SymbolAttrs.push_back(
GOFFObj->getZOSSymbolArchiveAttributes(S.getRawDataRefImpl()));
}
} else {
// For non-GOFF symbolic files (e.g. bitcode/IR), there is no z/OS
// archive attribute data available. Pad SymbolAttrs to stay in sync
// with Symbols.
D.SymbolAttrs.resize(D.Symbols.size());
}
}
if (D.SymFile)
HasObject = true;
// On z/OS, when there are no symbols, add a dummy blank symbol
// into the symbol table. This is done since the z/OS binder:
// - emits an error if there is no symbol table in the archive
// - emits an error if the symbol table has 0 symbols
// - should not find any references to a blank symbol
if (isZOSArchive(Kind) && (LastZosObjIndex == Index) &&
(SymNames.tell() == 0)) {
D.Symbols.push_back(0);
D.SymbolAttrs.push_back(0);
SymNames << ' ' << '\0';
}
}
Pos += D.Header.size() + D.Data.size() + D.Padding.size();
}
// If there are no symbols, emit an empty symbol table, to satisfy Solaris
// tools, older versions of which expect a symbol table in a non-empty
// archive, regardless of whether there are any symbols in it.
if (HasObject && SymNames.tell() == 0 && !isCOFFArchive(Kind))
SymNames << '\0' << '\0' << '\0';
return std::move(Ret);
}
namespace llvm {
static ErrorOr<SmallString<128>> canonicalizePath(StringRef P) {
SmallString<128> Ret = P;
std::error_code Err = sys::fs::make_absolute(Ret);
if (Err)
return Err;
sys::path::remove_dots(Ret, /*removedotdot*/ true);
return Ret;
}
// Compute the relative path from From to To.
Expected<std::string> computeArchiveRelativePath(StringRef From, StringRef To) {
ErrorOr<SmallString<128>> PathToOrErr = canonicalizePath(To);
ErrorOr<SmallString<128>> DirFromOrErr = canonicalizePath(From);
if (!PathToOrErr || !DirFromOrErr)
return errorCodeToError(errnoAsErrorCode());
const SmallString<128> &PathTo = *PathToOrErr;
const SmallString<128> &DirFrom = sys::path::parent_path(*DirFromOrErr);
// Can't construct a relative path between different roots
if (sys::path::root_name(PathTo) != sys::path::root_name(DirFrom))
return sys::path::convert_to_slash(PathTo);
// Skip common prefixes
auto FromTo =
std::mismatch(sys::path::begin(DirFrom), sys::path::end(DirFrom),
sys::path::begin(PathTo));
auto FromI = FromTo.first;
auto ToI = FromTo.second;
// Construct relative path
SmallString<128> Relative;
for (auto FromE = sys::path::end(DirFrom); FromI != FromE; ++FromI)
sys::path::append(Relative, sys::path::Style::posix, "..");
for (auto ToE = sys::path::end(PathTo); ToI != ToE; ++ToI)
sys::path::append(Relative, sys::path::Style::posix, *ToI);
return std::string(Relative);
}
Error writeArchiveToStream(raw_ostream &Out,
ArrayRef<NewArchiveMember> NewMembers,
SymtabWritingMode WriteSymtab,
object::Archive::Kind Kind, bool Deterministic,
bool Thin, std::optional<bool> IsEC,
function_ref<void(Error)> Warn) {
assert((!Thin || !isBSDLike(Kind)) && "Only the gnu format has a thin mode");
SmallString<0> SymNamesBuf;
raw_svector_ostream SymNames(SymNamesBuf);
SmallString<0> StringTableBuf;
raw_svector_ostream StringTable(StringTableBuf);
SymMap SymMap;
bool ShouldWriteSymtab = WriteSymtab != SymtabWritingMode::NoSymtab;
// COFF symbol map uses 16-bit indexes, so we can't use it if there are too
// many members. COFF format also requires symbol table presence, so use
// GNU format when NoSymtab is requested.
if (isCOFFArchive(Kind) && (NewMembers.size() > 0xfffe || !ShouldWriteSymtab))
Kind = object::Archive::K_GNU;
// In the scenario when LLVMContext is populated SymbolicFile will contain a
// reference to it, thus SymbolicFile should be destroyed first.
LLVMContext Context;
Expected<std::vector<MemberData>> DataOrErr = computeMemberData(
StringTable, SymNames, Kind, Thin, Deterministic, WriteSymtab,
isCOFFArchive(Kind) ? &SymMap : nullptr, Context, NewMembers, IsEC, Warn);
if (Error E = DataOrErr.takeError())
return E;
std::vector<MemberData> &Data = *DataOrErr;
uint64_t StringTableSize = 0;
MemberData StringTableMember;
if (!StringTableBuf.empty() && !isAIXBigArchive(Kind)) {
StringTableMember = computeStringTable(StringTableBuf);
StringTableSize = StringTableMember.Header.size() +
StringTableMember.Data.size() +
StringTableMember.Padding.size();
}
// We would like to detect if we need to switch to a 64-bit symbol table.
uint64_t LastMemberEndOffset = 0;
uint64_t LastMemberHeaderOffset = 0;
uint64_t NumSyms = 0;
uint64_t NumSyms32 = 0; // Store symbol number of 32-bit member files.
for (const auto &M : Data) {
// Record the start of the member's offset
LastMemberEndOffset += M.PreHeadPadSize;
LastMemberHeaderOffset = LastMemberEndOffset;
// Account for the size of each part associated with the member.
LastMemberEndOffset += M.Header.size() + M.Data.size() + M.Padding.size();
NumSyms += M.Symbols.size();
// AIX big archive files may contain two global symbol tables. The
// first global symbol table locates 32-bit file members that define global
// symbols; the second global symbol table does the same for 64-bit file
// members. As a big archive can have both 32-bit and 64-bit file members,
// we need to know the number of symbols in each symbol table individually.
if (isAIXBigArchive(Kind) && ShouldWriteSymtab) {
if (!is64BitSymbolicFile(M.SymFile.get()))
NumSyms32 += M.Symbols.size();
}
}
std::optional<uint64_t> HeadersSize;
// The symbol table is put at the end of the big archive file. The symbol
// table is at the start of the archive file for other archive formats.
if (ShouldWriteSymtab && !is64BitKind(Kind)) {
// We assume 32-bit offsets to see if 32-bit symbols are possible or not.
HeadersSize = computeHeadersSize(Kind, Data.size(), StringTableSize,
NumSyms, SymNamesBuf.size(),
isCOFFArchive(Kind) ? &SymMap : nullptr);
// The SYM64 format is used when an archive's member offsets are larger than
// 32-bits can hold. The need for this shift in format is detected by
// writeArchive. To test this we need to generate a file with a member that
// has an offset larger than 32-bits but this demands a very slow test. To
// speed the test up we use this environment variable to pretend like the
// cutoff happens before 32-bits and instead happens at some much smaller
// value.
uint64_t Sym64Threshold = 1ULL << 32;
const char *Sym64Env = std::getenv("SYM64_THRESHOLD");
if (Sym64Env)
StringRef(Sym64Env).getAsInteger(10, Sym64Threshold);
// If LastMemberHeaderOffset isn't going to fit in a 32-bit varible we need
// to switch to 64-bit. Note that the file can be larger than 4GB as long as
// the last member starts before the 4GB offset.
if (*HeadersSize + LastMemberHeaderOffset >= Sym64Threshold) {
switch (Kind) {
case object::Archive::K_COFF:
// COFF format has no 64-bit version, so we use GNU64 instead.
if (!SymMap.Map.empty() && !SymMap.ECMap.empty())
// Only the COFF format supports the ECSYMBOLS section, so don’t use
// GNU64 when two symbol maps are required.
return make_error<object::GenericBinaryError>(
"Archive is too large: ARM64X does not support archives larger "
"than 4GB");
// Since this changes the headers, we need to recalculate everything.
return writeArchiveToStream(Out, NewMembers, WriteSymtab,
object::Archive::K_GNU64, Deterministic,
Thin, IsEC, Warn);
case object::Archive::K_DARWIN:
Kind = object::Archive::K_DARWIN64;
break;
default:
Kind = object::Archive::K_GNU64;
break;
}
HeadersSize.reset();
}
}
if (Thin)
Out << "!<thin>\n";
else if (isAIXBigArchive(Kind))
Out << "<bigaf>\n";
else if (isZOSArchive(Kind))
Out << ZOSArchiveMagic;
else
Out << "!<arch>\n";
if (!isAIXBigArchive(Kind)) {
if (ShouldWriteSymtab) {
if (!HeadersSize)
HeadersSize = computeHeadersSize(
Kind, Data.size(), StringTableSize, NumSyms, SymNamesBuf.size(),
isCOFFArchive(Kind) ? &SymMap : nullptr);
writeSymbolTable(Out, Kind, Deterministic, Data, SymNamesBuf,
*HeadersSize, NumSyms);
if (isCOFFArchive(Kind))
writeSymbolMap(Out, Kind, Deterministic, Data, SymMap, *HeadersSize);
}
if (StringTableSize)
Out << StringTableMember.Header << StringTableMember.Data
<< StringTableMember.Padding;
if (ShouldWriteSymtab && SymMap.ECMap.size())
writeECSymbols(Out, Kind, Deterministic, Data, SymMap);
for (const MemberData &M : Data)
Out << M.Header << M.Data << M.Padding;
} else {
HeadersSize = sizeof(object::BigArchive::FixLenHdr);
LastMemberEndOffset += *HeadersSize;
LastMemberHeaderOffset += *HeadersSize;
// For the big archive (AIX) format, compute a table of member names and
// offsets, used in the member table.
uint64_t MemberTableNameStrTblSize = 0;
std::vector<size_t> MemberOffsets;
std::vector<StringRef> MemberNames;
// Loop across object to find offset and names.
uint64_t MemberEndOffset = sizeof(object::BigArchive::FixLenHdr);
for (size_t I = 0, Size = NewMembers.size(); I != Size; ++I) {
const NewArchiveMember &Member = NewMembers[I];
MemberTableNameStrTblSize += Member.MemberName.size() + 1;
MemberEndOffset += Data[I].PreHeadPadSize;
MemberOffsets.push_back(MemberEndOffset);
MemberNames.push_back(Member.MemberName);
// File member name ended with "`\n". The length is included in
// BigArMemHdrType.
MemberEndOffset += sizeof(object::BigArMemHdrType) +
alignTo(Data[I].Data.size(), 2) +
alignTo(Member.MemberName.size(), 2);
}
// AIX member table size.
uint64_t MemberTableSize = 20 + // Number of members field
20 * MemberOffsets.size() +
MemberTableNameStrTblSize;
SmallString<0> SymNamesBuf32;
SmallString<0> SymNamesBuf64;
raw_svector_ostream SymNames32(SymNamesBuf32);
raw_svector_ostream SymNames64(SymNamesBuf64);
if (ShouldWriteSymtab && NumSyms)
// Generate the symbol names for the members.
for (const auto &M : Data) {
Expected<std::vector<unsigned>> SymbolsOrErr = getSymbols(
M.SymFile.get(), 0,
is64BitSymbolicFile(M.SymFile.get()) ? SymNames64 : SymNames32,
nullptr);
if (!SymbolsOrErr)
return SymbolsOrErr.takeError();
}
uint64_t MemberTableEndOffset =
LastMemberEndOffset +
alignTo(sizeof(object::BigArMemHdrType) + MemberTableSize, 2);
// In AIX OS, The 'GlobSymOffset' field in the fixed-length header contains
// the offset to the 32-bit global symbol table, and the 'GlobSym64Offset'
// contains the offset to the 64-bit global symbol table.
uint64_t GlobalSymbolOffset =
(ShouldWriteSymtab &&
(WriteSymtab != SymtabWritingMode::BigArchive64) && NumSyms32 > 0)
? MemberTableEndOffset
: 0;
uint64_t GlobalSymbolOffset64 = 0;
uint64_t NumSyms64 = NumSyms - NumSyms32;
if (ShouldWriteSymtab && (WriteSymtab != SymtabWritingMode::BigArchive32) &&
NumSyms64 > 0) {
if (GlobalSymbolOffset == 0)
GlobalSymbolOffset64 = MemberTableEndOffset;
else
// If there is a global symbol table for 32-bit members,
// the 64-bit global symbol table is after the 32-bit one.
GlobalSymbolOffset64 =
GlobalSymbolOffset + sizeof(object::BigArMemHdrType) +
(NumSyms32 + 1) * 8 + alignTo(SymNamesBuf32.size(), 2);
}
// Fixed Sized Header.
printWithSpacePadding(Out, NewMembers.size() ? LastMemberEndOffset : 0,
20); // Offset to member table
// If there are no file members in the archive, there will be no global
// symbol table.
printWithSpacePadding(Out, GlobalSymbolOffset, 20);
printWithSpacePadding(Out, GlobalSymbolOffset64, 20);
printWithSpacePadding(Out,
NewMembers.size()
? sizeof(object::BigArchive::FixLenHdr) +
Data[0].PreHeadPadSize
: 0,
20); // Offset to first archive member
printWithSpacePadding(Out, NewMembers.size() ? LastMemberHeaderOffset : 0,
20); // Offset to last archive member
printWithSpacePadding(
Out, 0,
20); // Offset to first member of free list - Not supported yet
for (const MemberData &M : Data) {
Out << std::string(M.PreHeadPadSize, '\0');
Out << M.Header << M.Data;
if (M.Data.size() % 2)
Out << '\0';
}
if (NewMembers.size()) {
// Member table.
printBigArchiveMemberHeader(Out, "", sys::toTimePoint(0), 0, 0, 0,
MemberTableSize, LastMemberHeaderOffset,
GlobalSymbolOffset ? GlobalSymbolOffset
: GlobalSymbolOffset64);
printWithSpacePadding(Out, MemberOffsets.size(), 20); // Number of members
for (uint64_t MemberOffset : MemberOffsets)
printWithSpacePadding(Out, MemberOffset,
20); // Offset to member file header.
for (StringRef MemberName : MemberNames)
Out << MemberName << '\0'; // Member file name, null byte padding.
if (MemberTableNameStrTblSize % 2)
Out << '\0'; // Name table must be tail padded to an even number of
// bytes.
if (ShouldWriteSymtab) {
// Write global symbol table for 32-bit file members.
if (GlobalSymbolOffset) {
writeSymbolTable(Out, Kind, Deterministic, Data, SymNamesBuf32,
*HeadersSize, NumSyms32, LastMemberEndOffset,
GlobalSymbolOffset64);
// Add padding between the symbol tables, if needed.
if (GlobalSymbolOffset64 && (SymNamesBuf32.size() % 2))
Out << '\0';
}
// Write global symbol table for 64-bit file members.
if (GlobalSymbolOffset64)
writeSymbolTable(Out, Kind, Deterministic, Data, SymNamesBuf64,
*HeadersSize, NumSyms64,
GlobalSymbolOffset ? GlobalSymbolOffset
: LastMemberEndOffset,
0, true);
}
}
}
Out.flush();
return Error::success();
}
void warnToStderr(Error Err) {
llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "warning: ");
}
Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers,
SymtabWritingMode WriteSymtab, object::Archive::Kind Kind,
bool Deterministic, bool Thin,
std::unique_ptr<MemoryBuffer> OldArchiveBuf,
std::optional<bool> IsEC, function_ref<void(Error)> Warn) {
Expected<sys::fs::TempFile> Temp =
sys::fs::TempFile::create(ArcName + ".temp-archive-%%%%%%%.a");
if (!Temp)
return Temp.takeError();
raw_fd_ostream Out(Temp->FD, false);
if (Error E = writeArchiveToStream(Out, NewMembers, WriteSymtab, Kind,
Deterministic, Thin, IsEC, Warn)) {
if (Error DiscardError = Temp->discard())
return joinErrors(std::move(E), std::move(DiscardError));
return E;
}
// At this point, we no longer need whatever backing memory
// was used to generate the NewMembers. On Windows, this buffer
// could be a mapped view of the file we want to replace (if
// we're updating an existing archive, say). In that case, the
// rename would still succeed, but it would leave behind a
// temporary file (actually the original file renamed) because
// a file cannot be deleted while there's a handle open on it,
// only renamed. So by freeing this buffer, this ensures that
// the last open handle on the destination file, if any, is
// closed before we attempt to rename.
OldArchiveBuf.reset();
return Temp->keep(ArcName);
}
Expected<std::unique_ptr<MemoryBuffer>>
writeArchiveToBuffer(ArrayRef<NewArchiveMember> NewMembers,
SymtabWritingMode WriteSymtab, object::Archive::Kind Kind,
bool Deterministic, bool Thin,
function_ref<void(Error)> Warn) {
SmallVector<char, 0> ArchiveBufferVector;
raw_svector_ostream ArchiveStream(ArchiveBufferVector);
if (Error E =
writeArchiveToStream(ArchiveStream, NewMembers, WriteSymtab, Kind,
Deterministic, Thin, std::nullopt, Warn))
return std::move(E);
return std::make_unique<SmallVectorMemoryBuffer>(
std::move(ArchiveBufferVector), /*RequiresNullTerminator=*/false);
}
} // namespace llvm