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llvm-project/llvm/lib/Object/Archive.cpp

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//===- Archive.cpp - ar File Format implementation --------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the ArchiveObjectFile class.
//
//===----------------------------------------------------------------------===//
#include "llvm/Object/Archive.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
using namespace llvm;
using namespace object;
using namespace llvm::support::endian;
static const char *const Magic = "!<arch>\n";
static const char *const ThinMagic = "!<thin>\n";
void Archive::anchor() { }
StringRef ArchiveMemberHeader::getName() const {
char EndCond;
if (Name[0] == '/' || Name[0] == '#')
EndCond = ' ';
else
EndCond = '/';
llvm::StringRef::size_type end =
llvm::StringRef(Name, sizeof(Name)).find(EndCond);
if (end == llvm::StringRef::npos)
end = sizeof(Name);
assert(end <= sizeof(Name) && end > 0);
// Don't include the EndCond if there is one.
return llvm::StringRef(Name, end);
}
ErrorOr<uint32_t> ArchiveMemberHeader::getSize() const {
uint32_t Ret;
if (llvm::StringRef(Size, sizeof(Size)).rtrim(" ").getAsInteger(10, Ret))
return object_error::parse_failed; // Size is not a decimal number.
return Ret;
}
sys::fs::perms ArchiveMemberHeader::getAccessMode() const {
unsigned Ret;
if (StringRef(AccessMode, sizeof(AccessMode)).rtrim(' ').getAsInteger(8, Ret))
llvm_unreachable("Access mode is not an octal number.");
return static_cast<sys::fs::perms>(Ret);
}
sys::TimeValue ArchiveMemberHeader::getLastModified() const {
unsigned Seconds;
if (StringRef(LastModified, sizeof(LastModified)).rtrim(' ')
.getAsInteger(10, Seconds))
llvm_unreachable("Last modified time not a decimal number.");
sys::TimeValue Ret;
Ret.fromEpochTime(Seconds);
return Ret;
}
unsigned ArchiveMemberHeader::getUID() const {
unsigned Ret;
StringRef User = StringRef(UID, sizeof(UID)).rtrim(' ');
if (User.empty())
return 0;
if (User.getAsInteger(10, Ret))
llvm_unreachable("UID time not a decimal number.");
return Ret;
}
unsigned ArchiveMemberHeader::getGID() const {
unsigned Ret;
StringRef Group = StringRef(GID, sizeof(GID)).rtrim(' ');
if (Group.empty())
return 0;
if (Group.getAsInteger(10, Ret))
llvm_unreachable("GID time not a decimal number.");
return Ret;
}
Archive::Child::Child(const Archive *Parent, StringRef Data,
uint16_t StartOfFile)
: Parent(Parent), Data(Data), StartOfFile(StartOfFile) {}
Archive::Child::Child(const Archive *Parent, const char *Start,
std::error_code *EC)
: Parent(Parent) {
if (!Start)
return;
uint64_t Size = sizeof(ArchiveMemberHeader);
Data = StringRef(Start, Size);
if (!isThinMember()) {
ErrorOr<uint64_t> MemberSize = getRawSize();
if ((*EC = MemberSize.getError()))
return;
Size += MemberSize.get();
Data = StringRef(Start, Size);
}
// Setup StartOfFile and PaddingBytes.
StartOfFile = sizeof(ArchiveMemberHeader);
// Don't include attached name.
StringRef Name = getRawName();
if (Name.startswith("#1/")) {
uint64_t NameSize;
if (Name.substr(3).rtrim(' ').getAsInteger(10, NameSize))
llvm_unreachable("Long name length is not an integer");
StartOfFile += NameSize;
}
}
ErrorOr<uint64_t> Archive::Child::getSize() const {
if (Parent->IsThin) {
ErrorOr<uint32_t> Size = getHeader()->getSize();
if (std::error_code EC = Size.getError())
return EC;
return Size.get();
}
return Data.size() - StartOfFile;
}
ErrorOr<uint64_t> Archive::Child::getRawSize() const {
ErrorOr<uint32_t> Size = getHeader()->getSize();
if (std::error_code EC = Size.getError())
return EC;
return Size.get();
}
bool Archive::Child::isThinMember() const {
StringRef Name = getHeader()->getName();
return Parent->IsThin && Name != "/" && Name != "//";
}
ErrorOr<std::string> Archive::Child::getFullName() const {
assert(isThinMember());
ErrorOr<StringRef> NameOrErr = getName();
if (std::error_code EC = NameOrErr.getError())
return EC;
StringRef Name = *NameOrErr;
if (sys::path::is_absolute(Name))
return Name;
SmallString<128> FullName = sys::path::parent_path(
Parent->getMemoryBufferRef().getBufferIdentifier());
sys::path::append(FullName, Name);
return StringRef(FullName);
}
ErrorOr<StringRef> Archive::Child::getBuffer() const {
if (!isThinMember()) {
ErrorOr<uint32_t> Size = getSize();
if (std::error_code EC = Size.getError())
return EC;
return StringRef(Data.data() + StartOfFile, Size.get());
}
ErrorOr<std::string> FullNameOrEr = getFullName();
if (std::error_code EC = FullNameOrEr.getError())
return EC;
const std::string &FullName = *FullNameOrEr;
ErrorOr<std::unique_ptr<MemoryBuffer>> Buf = MemoryBuffer::getFile(FullName);
if (std::error_code EC = Buf.getError())
return EC;
Parent->ThinBuffers.push_back(std::move(*Buf));
return Parent->ThinBuffers.back()->getBuffer();
}
ErrorOr<Archive::Child> Archive::Child::getNext() const {
size_t SpaceToSkip = Data.size();
// If it's odd, add 1 to make it even.
if (SpaceToSkip & 1)
++SpaceToSkip;
const char *NextLoc = Data.data() + SpaceToSkip;
// Check to see if this is at the end of the archive.
if (NextLoc == Parent->Data.getBufferEnd())
return Child(Parent, nullptr, nullptr);
// Check to see if this is past the end of the archive.
if (NextLoc > Parent->Data.getBufferEnd())
return object_error::parse_failed;
std::error_code EC;
Child Ret(Parent, NextLoc, &EC);
if (EC)
return EC;
return Ret;
}
uint64_t Archive::Child::getChildOffset() const {
const char *a = Parent->Data.getBuffer().data();
const char *c = Data.data();
uint64_t offset = c - a;
return offset;
}
ErrorOr<StringRef> Archive::Child::getName() const {
StringRef name = getRawName();
// Check if it's a special name.
if (name[0] == '/') {
if (name.size() == 1) // Linker member.
return name;
if (name.size() == 2 && name[1] == '/') // String table.
return name;
// It's a long name.
// Get the offset.
std::size_t offset;
if (name.substr(1).rtrim(' ').getAsInteger(10, offset))
llvm_unreachable("Long name offset is not an integer");
// Verify it.
if (offset >= Parent->StringTable.size())
return object_error::parse_failed;
const char *addr = Parent->StringTable.begin() + offset;
// GNU long file names end with a "/\n".
if (Parent->kind() == K_GNU || Parent->kind() == K_MIPS64) {
StringRef::size_type End = StringRef(addr).find('\n');
return StringRef(addr, End - 1);
}
return StringRef(addr);
} else if (name.startswith("#1/")) {
uint64_t name_size;
if (name.substr(3).rtrim(' ').getAsInteger(10, name_size))
llvm_unreachable("Long name length is not an ingeter");
return Data.substr(sizeof(ArchiveMemberHeader), name_size).rtrim('\0');
} else {
// It is not a long name so trim the blanks at the end of the name.
if (name[name.size() - 1] != '/') {
return name.rtrim(' ');
}
}
// It's a simple name.
if (name[name.size() - 1] == '/')
return name.substr(0, name.size() - 1);
return name;
}
ErrorOr<MemoryBufferRef> Archive::Child::getMemoryBufferRef() const {
ErrorOr<StringRef> NameOrErr = getName();
if (std::error_code EC = NameOrErr.getError())
return EC;
StringRef Name = NameOrErr.get();
ErrorOr<StringRef> Buf = getBuffer();
if (std::error_code EC = Buf.getError())
return EC;
return MemoryBufferRef(*Buf, Name);
}
Expected<std::unique_ptr<Binary>>
Archive::Child::getAsBinary(LLVMContext *Context) const {
ErrorOr<MemoryBufferRef> BuffOrErr = getMemoryBufferRef();
if (std::error_code EC = BuffOrErr.getError())
return errorCodeToError(EC);
auto BinaryOrErr = createBinary(BuffOrErr.get(), Context);
if (BinaryOrErr)
return std::move(*BinaryOrErr);
return BinaryOrErr.takeError();
}
Expected<std::unique_ptr<Archive>> Archive::create(MemoryBufferRef Source) {
Error Err;
std::unique_ptr<Archive> Ret(new Archive(Source, Err));
if (Err)
return std::move(Err);
return std::move(Ret);
}
void Archive::setFirstRegular(const Child &C) {
FirstRegularData = C.Data;
FirstRegularStartOfFile = C.StartOfFile;
}
Archive::Archive(MemoryBufferRef Source, Error &Err)
: Binary(Binary::ID_Archive, Source) {
ErrorAsOutParameter ErrAsOutParam(Err);
StringRef Buffer = Data.getBuffer();
// Check for sufficient magic.
if (Buffer.startswith(ThinMagic)) {
IsThin = true;
} else if (Buffer.startswith(Magic)) {
IsThin = false;
} else {
Err = make_error<GenericBinaryError>("File too small to be an archive",
object_error::invalid_file_type);
return;
}
// Get the special members.
child_iterator I = child_begin(false);
std::error_code ec;
if ((ec = I->getError())) {
Err = errorCodeToError(ec);
return;
}
child_iterator E = child_end();
// This is at least a valid empty archive. Since an empty archive is the
// same in all formats, just claim it to be gnu to make sure Format is
// initialized.
Format = K_GNU;
if (I == E) {
Err = Error::success();
return;
}
const Child *C = &**I;
auto Increment = [&]() {
++I;
if ((Err = errorCodeToError(I->getError())))
return true;
C = &**I;
return false;
};
StringRef Name = C->getRawName();
// Below is the pattern that is used to figure out the archive format
// GNU archive format
// First member : / (may exist, if it exists, points to the symbol table )
// Second member : // (may exist, if it exists, points to the string table)
// Note : The string table is used if the filename exceeds 15 characters
// BSD archive format
// First member : __.SYMDEF or "__.SYMDEF SORTED" (the symbol table)
// There is no string table, if the filename exceeds 15 characters or has a
// embedded space, the filename has #1/<size>, The size represents the size
// of the filename that needs to be read after the archive header
// COFF archive format
// First member : /
// Second member : / (provides a directory of symbols)
// Third member : // (may exist, if it exists, contains the string table)
// Note: Microsoft PE/COFF Spec 8.3 says that the third member is present
// even if the string table is empty. However, lib.exe does not in fact
// seem to create the third member if there's no member whose filename
// exceeds 15 characters. So the third member is optional.
if (Name == "__.SYMDEF" || Name == "__.SYMDEF_64") {
if (Name == "__.SYMDEF")
Format = K_BSD;
else // Name == "__.SYMDEF_64"
Format = K_DARWIN64;
// We know that the symbol table is not an external file, so we just assert
// there is no error.
SymbolTable = *C->getBuffer();
if (Increment())
return;
setFirstRegular(*C);
Err = Error::success();
return;
}
if (Name.startswith("#1/")) {
Format = K_BSD;
// We know this is BSD, so getName will work since there is no string table.
ErrorOr<StringRef> NameOrErr = C->getName();
ec = NameOrErr.getError();
if (ec) {
Err = errorCodeToError(ec);
return;
}
Name = NameOrErr.get();
if (Name == "__.SYMDEF SORTED" || Name == "__.SYMDEF") {
// We know that the symbol table is not an external file, so we just
// assert there is no error.
SymbolTable = *C->getBuffer();
if (Increment())
return;
}
else if (Name == "__.SYMDEF_64 SORTED" || Name == "__.SYMDEF_64") {
Format = K_DARWIN64;
// We know that the symbol table is not an external file, so we just
// assert there is no error.
SymbolTable = *C->getBuffer();
if (Increment())
return;
}
setFirstRegular(*C);
return;
}
// MIPS 64-bit ELF archives use a special format of a symbol table.
// This format is marked by `ar_name` field equals to "/SYM64/".
// For detailed description see page 96 in the following document:
// http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf
bool has64SymTable = false;
if (Name == "/" || Name == "/SYM64/") {
// We know that the symbol table is not an external file, so we just assert
// there is no error.
SymbolTable = *C->getBuffer();
if (Name == "/SYM64/")
has64SymTable = true;
if (Increment())
return;
if (I == E) {
Err = Error::success();
return;
}
Name = C->getRawName();
}
if (Name == "//") {
Format = has64SymTable ? K_MIPS64 : K_GNU;
// The string table is never an external member, so we just assert on the
// ErrorOr.
StringTable = *C->getBuffer();
if (Increment())
return;
setFirstRegular(*C);
Err = Error::success();
return;
}
if (Name[0] != '/') {
Format = has64SymTable ? K_MIPS64 : K_GNU;
setFirstRegular(*C);
Err = Error::success();
return;
}
if (Name != "/") {
Err = errorCodeToError(object_error::parse_failed);
return;
}
Format = K_COFF;
// We know that the symbol table is not an external file, so we just assert
// there is no error.
SymbolTable = *C->getBuffer();
if (Increment())
return;
if (I == E) {
setFirstRegular(*C);
Err = Error::success();
return;
}
Name = C->getRawName();
if (Name == "//") {
// The string table is never an external member, so we just assert on the
// ErrorOr.
StringTable = *C->getBuffer();
if (Increment())
return;
}
setFirstRegular(*C);
Err = Error::success();
}
Archive::child_iterator Archive::child_begin(bool SkipInternal) const {
if (Data.getBufferSize() == 8) // empty archive.
return child_end();
if (SkipInternal)
return Child(this, FirstRegularData, FirstRegularStartOfFile);
const char *Loc = Data.getBufferStart() + strlen(Magic);
std::error_code EC;
Child c(this, Loc, &EC);
if (EC)
return child_iterator(EC);
return child_iterator(c);
}
Archive::child_iterator Archive::child_end() const {
return Child(this, nullptr, nullptr);
}
StringRef Archive::Symbol::getName() const {
return Parent->getSymbolTable().begin() + StringIndex;
}
ErrorOr<Archive::Child> Archive::Symbol::getMember() const {
const char *Buf = Parent->getSymbolTable().begin();
const char *Offsets = Buf;
if (Parent->kind() == K_MIPS64 || Parent->kind() == K_DARWIN64)
Offsets += sizeof(uint64_t);
else
Offsets += sizeof(uint32_t);
uint32_t Offset = 0;
if (Parent->kind() == K_GNU) {
Offset = read32be(Offsets + SymbolIndex * 4);
} else if (Parent->kind() == K_MIPS64) {
Offset = read64be(Offsets + SymbolIndex * 8);
} else if (Parent->kind() == K_BSD) {
// The SymbolIndex is an index into the ranlib structs that start at
// Offsets (the first uint32_t is the number of bytes of the ranlib
// structs). The ranlib structs are a pair of uint32_t's the first
// being a string table offset and the second being the offset into
// the archive of the member that defines the symbol. Which is what
// is needed here.
Offset = read32le(Offsets + SymbolIndex * 8 + 4);
} else if (Parent->kind() == K_DARWIN64) {
// The SymbolIndex is an index into the ranlib_64 structs that start at
// Offsets (the first uint64_t is the number of bytes of the ranlib_64
// structs). The ranlib_64 structs are a pair of uint64_t's the first
// being a string table offset and the second being the offset into
// the archive of the member that defines the symbol. Which is what
// is needed here.
Offset = read64le(Offsets + SymbolIndex * 16 + 8);
} else {
// Skip offsets.
uint32_t MemberCount = read32le(Buf);
Buf += MemberCount * 4 + 4;
uint32_t SymbolCount = read32le(Buf);
if (SymbolIndex >= SymbolCount)
return object_error::parse_failed;
// Skip SymbolCount to get to the indices table.
const char *Indices = Buf + 4;
// Get the index of the offset in the file member offset table for this
// symbol.
uint16_t OffsetIndex = read16le(Indices + SymbolIndex * 2);
// Subtract 1 since OffsetIndex is 1 based.
--OffsetIndex;
if (OffsetIndex >= MemberCount)
return object_error::parse_failed;
Offset = read32le(Offsets + OffsetIndex * 4);
}
const char *Loc = Parent->getData().begin() + Offset;
std::error_code EC;
Child C(Parent, Loc, &EC);
if (EC)
return EC;
return C;
}
Archive::Symbol Archive::Symbol::getNext() const {
Symbol t(*this);
if (Parent->kind() == K_BSD) {
// t.StringIndex is an offset from the start of the __.SYMDEF or
// "__.SYMDEF SORTED" member into the string table for the ranlib
// struct indexed by t.SymbolIndex . To change t.StringIndex to the
// offset in the string table for t.SymbolIndex+1 we subtract the
// its offset from the start of the string table for t.SymbolIndex
// and add the offset of the string table for t.SymbolIndex+1.
// The __.SYMDEF or "__.SYMDEF SORTED" member starts with a uint32_t
// which is the number of bytes of ranlib structs that follow. The ranlib
// structs are a pair of uint32_t's the first being a string table offset
// and the second being the offset into the archive of the member that
// define the symbol. After that the next uint32_t is the byte count of
// the string table followed by the string table.
const char *Buf = Parent->getSymbolTable().begin();
uint32_t RanlibCount = 0;
RanlibCount = read32le(Buf) / 8;
// If t.SymbolIndex + 1 will be past the count of symbols (the RanlibCount)
// don't change the t.StringIndex as we don't want to reference a ranlib
// past RanlibCount.
if (t.SymbolIndex + 1 < RanlibCount) {
const char *Ranlibs = Buf + 4;
uint32_t CurRanStrx = 0;
uint32_t NextRanStrx = 0;
CurRanStrx = read32le(Ranlibs + t.SymbolIndex * 8);
NextRanStrx = read32le(Ranlibs + (t.SymbolIndex + 1) * 8);
t.StringIndex -= CurRanStrx;
t.StringIndex += NextRanStrx;
}
} else {
// Go to one past next null.
t.StringIndex = Parent->getSymbolTable().find('\0', t.StringIndex) + 1;
}
++t.SymbolIndex;
return t;
}
Archive::symbol_iterator Archive::symbol_begin() const {
if (!hasSymbolTable())
return symbol_iterator(Symbol(this, 0, 0));
const char *buf = getSymbolTable().begin();
if (kind() == K_GNU) {
uint32_t symbol_count = 0;
symbol_count = read32be(buf);
buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t)));
} else if (kind() == K_MIPS64) {
uint64_t symbol_count = read64be(buf);
buf += sizeof(uint64_t) + (symbol_count * (sizeof(uint64_t)));
} else if (kind() == K_BSD) {
// The __.SYMDEF or "__.SYMDEF SORTED" member starts with a uint32_t
// which is the number of bytes of ranlib structs that follow. The ranlib
// structs are a pair of uint32_t's the first being a string table offset
// and the second being the offset into the archive of the member that
// define the symbol. After that the next uint32_t is the byte count of
// the string table followed by the string table.
uint32_t ranlib_count = 0;
ranlib_count = read32le(buf) / 8;
const char *ranlibs = buf + 4;
uint32_t ran_strx = 0;
ran_strx = read32le(ranlibs);
buf += sizeof(uint32_t) + (ranlib_count * (2 * (sizeof(uint32_t))));
// Skip the byte count of the string table.
buf += sizeof(uint32_t);
buf += ran_strx;
} else if (kind() == K_DARWIN64) {
// The __.SYMDEF_64 or "__.SYMDEF_64 SORTED" member starts with a uint64_t
// which is the number of bytes of ranlib_64 structs that follow. The
// ranlib_64 structs are a pair of uint64_t's the first being a string
// table offset and the second being the offset into the archive of the
// member that define the symbol. After that the next uint64_t is the byte
// count of the string table followed by the string table.
uint64_t ranlib_count = 0;
ranlib_count = read64le(buf) / 16;
const char *ranlibs = buf + 8;
uint64_t ran_strx = 0;
ran_strx = read64le(ranlibs);
buf += sizeof(uint64_t) + (ranlib_count * (2 * (sizeof(uint64_t))));
// Skip the byte count of the string table.
buf += sizeof(uint64_t);
buf += ran_strx;
} else {
uint32_t member_count = 0;
uint32_t symbol_count = 0;
member_count = read32le(buf);
buf += 4 + (member_count * 4); // Skip offsets.
symbol_count = read32le(buf);
buf += 4 + (symbol_count * 2); // Skip indices.
}
uint32_t string_start_offset = buf - getSymbolTable().begin();
return symbol_iterator(Symbol(this, 0, string_start_offset));
}
Archive::symbol_iterator Archive::symbol_end() const {
return symbol_iterator(Symbol(this, getNumberOfSymbols(), 0));
}
uint32_t Archive::getNumberOfSymbols() const {
if (!hasSymbolTable())
return 0;
const char *buf = getSymbolTable().begin();
if (kind() == K_GNU)
return read32be(buf);
if (kind() == K_MIPS64)
return read64be(buf);
if (kind() == K_BSD)
return read32le(buf) / 8;
if (kind() == K_DARWIN64)
return read64le(buf) / 16;
uint32_t member_count = 0;
member_count = read32le(buf);
buf += 4 + (member_count * 4); // Skip offsets.
return read32le(buf);
}
Archive::child_iterator Archive::findSym(StringRef name) const {
Archive::symbol_iterator bs = symbol_begin();
Archive::symbol_iterator es = symbol_end();
for (; bs != es; ++bs) {
StringRef SymName = bs->getName();
if (SymName == name) {
ErrorOr<Archive::child_iterator> ResultOrErr = bs->getMember();
// FIXME: Should we really eat the error?
if (ResultOrErr.getError())
return child_end();
return ResultOrErr.get();
}
}
return child_end();
}
bool Archive::hasSymbolTable() const { return !SymbolTable.empty(); }
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