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Diffstat (limited to 'contrib/llvm/lib/Object/Archive.cpp')
-rw-r--r-- | contrib/llvm/lib/Object/Archive.cpp | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Object/Archive.cpp b/contrib/llvm/lib/Object/Archive.cpp new file mode 100644 index 0000000..0e13d05 --- /dev/null +++ b/contrib/llvm/lib/Object/Archive.cpp @@ -0,0 +1,301 @@ +//===- 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/APInt.h" +#include "llvm/Support/Endian.h" +#include "llvm/Support/MemoryBuffer.h" + +using namespace llvm; +using namespace object; + +static const char *Magic = "!<arch>\n"; + +static bool isInternalMember(const ArchiveMemberHeader &amh) { + static const char *const internals[] = { + "/", + "//", + "#_LLVM_SYM_TAB_#" + }; + + StringRef name = amh.getName(); + for (std::size_t i = 0; i < sizeof(internals) / sizeof(*internals); ++i) { + if (name == internals[i]) + return true; + } + return false; +} + +void Archive::anchor() { } + +error_code Archive::Child::getName(StringRef &Result) const { + StringRef name = ToHeader(Data.data())->getName(); + // Check if it's a special name. + if (name[0] == '/') { + if (name.size() == 1) { // Linker member. + Result = name; + return object_error::success; + } + if (name.size() == 2 && name[1] == '/') { // String table. + Result = name; + return object_error::success; + } + // 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"); + const char *addr = Parent->StringTable->Data.begin() + + sizeof(ArchiveMemberHeader) + + offset; + // Verify it. + if (Parent->StringTable == Parent->end_children() + || addr < (Parent->StringTable->Data.begin() + + sizeof(ArchiveMemberHeader)) + || addr > (Parent->StringTable->Data.begin() + + sizeof(ArchiveMemberHeader) + + Parent->StringTable->getSize())) + return object_error::parse_failed; + + // GNU long file names end with a /. + if (Parent->kind() == K_GNU) { + StringRef::size_type End = StringRef(addr).find('/'); + Result = StringRef(addr, End); + } else { + Result = addr; + } + return object_error::success; + } 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"); + Result = Data.substr(sizeof(ArchiveMemberHeader), name_size); + return object_error::success; + } + // It's a simple name. + if (name[name.size() - 1] == '/') + Result = name.substr(0, name.size() - 1); + else + Result = name; + return object_error::success; +} + +error_code Archive::Child::getAsBinary(OwningPtr<Binary> &Result) const { + OwningPtr<Binary> ret; + OwningPtr<MemoryBuffer> Buff; + if (error_code ec = getMemoryBuffer(Buff)) + return ec; + if (error_code ec = createBinary(Buff.take(), ret)) + return ec; + Result.swap(ret); + return object_error::success; +} + +Archive::Archive(MemoryBuffer *source, error_code &ec) + : Binary(Binary::ID_Archive, source) { + // Check for sufficient magic. + if (!source || source->getBufferSize() + < (8 + sizeof(ArchiveMemberHeader) + 2) // Smallest archive. + || StringRef(source->getBufferStart(), 8) != Magic) { + ec = object_error::invalid_file_type; + return; + } + + // Get the special members. + child_iterator i = begin_children(false); + child_iterator e = end_children(); + + StringRef name; + if ((ec = i->getName(name))) + return; + + // Below is the pattern that is used to figure out the archive format + // GNU archive format + // First member : / (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 (points to 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 : // contains the string table, this is present even if the + // string table is empty + if (name == "/") { + SymbolTable = i; + StringTable = e; + if (i != e) ++i; + if (i == e) { + ec = object_error::parse_failed; + return; + } + if ((ec = i->getName(name))) + return; + if (name[0] != '/') { + Format = K_GNU; + } else if ((name.size() > 1) && (name == "//")) { + Format = K_GNU; + StringTable = i; + ++i; + } else { + Format = K_COFF; + if (i != e) { + SymbolTable = i; + ++i; + } + if (i != e) { + StringTable = i; + } + } + } else if (name == "__.SYMDEF") { + Format = K_BSD; + SymbolTable = i; + StringTable = e; + } + ec = object_error::success; +} + +Archive::child_iterator Archive::begin_children(bool skip_internal) const { + const char *Loc = Data->getBufferStart() + strlen(Magic); + size_t Size = sizeof(ArchiveMemberHeader) + + ToHeader(Loc)->getSize(); + Child c(this, StringRef(Loc, Size)); + // Skip internals at the beginning of an archive. + if (skip_internal && isInternalMember(*ToHeader(Loc))) + return c.getNext(); + return c; +} + +Archive::child_iterator Archive::end_children() const { + return Child(this, StringRef(0, 0)); +} + +error_code Archive::Symbol::getName(StringRef &Result) const { + Result = StringRef(Parent->SymbolTable->getBuffer().begin() + StringIndex); + return object_error::success; +} + +error_code Archive::Symbol::getMember(child_iterator &Result) const { + const char *Buf = Parent->SymbolTable->getBuffer().begin(); + const char *Offsets = Buf + 4; + uint32_t Offset = 0; + if (Parent->kind() == K_GNU) { + Offset = *(reinterpret_cast<const support::ubig32_t*>(Offsets) + + SymbolIndex); + } else if (Parent->kind() == K_BSD) { + llvm_unreachable("BSD format is not supported"); + } else { + uint32_t MemberCount = *reinterpret_cast<const support::ulittle32_t*>(Buf); + + // Skip offsets. + Buf += sizeof(support::ulittle32_t) + + (MemberCount * sizeof(support::ulittle32_t)); + + uint32_t SymbolCount = *reinterpret_cast<const support::ulittle32_t*>(Buf); + + if (SymbolIndex >= SymbolCount) + return object_error::parse_failed; + + // Skip SymbolCount to get to the indices table. + const char *Indices = Buf + sizeof(support::ulittle32_t); + + // Get the index of the offset in the file member offset table for this + // symbol. + uint16_t OffsetIndex = + *(reinterpret_cast<const support::ulittle16_t*>(Indices) + + SymbolIndex); + // Subtract 1 since OffsetIndex is 1 based. + --OffsetIndex; + + if (OffsetIndex >= MemberCount) + return object_error::parse_failed; + + Offset = *(reinterpret_cast<const support::ulittle32_t*>(Offsets) + + OffsetIndex); + } + + const char *Loc = Parent->getData().begin() + Offset; + size_t Size = sizeof(ArchiveMemberHeader) + + ToHeader(Loc)->getSize(); + Result = Child(Parent, StringRef(Loc, Size)); + + return object_error::success; +} + +Archive::Symbol Archive::Symbol::getNext() const { + Symbol t(*this); + // Go to one past next null. + t.StringIndex = + Parent->SymbolTable->getBuffer().find('\0', t.StringIndex) + 1; + ++t.SymbolIndex; + return t; +} + +Archive::symbol_iterator Archive::begin_symbols() const { + const char *buf = SymbolTable->getBuffer().begin(); + if (kind() == K_GNU) { + uint32_t symbol_count = 0; + symbol_count = *reinterpret_cast<const support::ubig32_t*>(buf); + buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t))); + } else if (kind() == K_BSD) { + llvm_unreachable("BSD archive format is not supported"); + } else { + uint32_t member_count = 0; + uint32_t symbol_count = 0; + member_count = *reinterpret_cast<const support::ulittle32_t*>(buf); + buf += 4 + (member_count * 4); // Skip offsets. + symbol_count = *reinterpret_cast<const support::ulittle32_t*>(buf); + buf += 4 + (symbol_count * 2); // Skip indices. + } + uint32_t string_start_offset = buf - SymbolTable->getBuffer().begin(); + return symbol_iterator(Symbol(this, 0, string_start_offset)); +} + +Archive::symbol_iterator Archive::end_symbols() const { + const char *buf = SymbolTable->getBuffer().begin(); + uint32_t symbol_count = 0; + if (kind() == K_GNU) { + symbol_count = *reinterpret_cast<const support::ubig32_t*>(buf); + buf += sizeof(uint32_t) + (symbol_count * (sizeof(uint32_t))); + } else if (kind() == K_BSD) { + llvm_unreachable("BSD archive format is not supported"); + } else { + uint32_t member_count = 0; + member_count = *reinterpret_cast<const support::ulittle32_t*>(buf); + buf += 4 + (member_count * 4); // Skip offsets. + symbol_count = *reinterpret_cast<const support::ulittle32_t*>(buf); + } + return symbol_iterator( + Symbol(this, symbol_count, 0)); +} + +Archive::child_iterator Archive::findSym(StringRef name) const { + Archive::symbol_iterator bs = begin_symbols(); + Archive::symbol_iterator es = end_symbols(); + Archive::child_iterator result; + + StringRef symname; + for (; bs != es; ++bs) { + if (bs->getName(symname)) + return end_children(); + if (symname == name) { + if (bs->getMember(result)) + return end_children(); + return result; + } + } + return end_children(); +} |