https://github.com/Kitware/CMake
Tip revision: 25d2850c190ba915a7527a29dda6efe61be901f0 authored by Brad King on 21 March 2024, 13:32:22 UTC
CMake 3.29.0
CMake 3.29.0
Tip revision: 25d2850
cmXCOFF.cxx
/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
file Copyright.txt or https://cmake.org/licensing for details. */
#include "cmXCOFF.h"
#include <algorithm>
#include <cstddef>
#include <cm/memory>
#include "cmsys/FStream.hxx"
#include "cmStringAlgorithms.h"
// Include the XCOFF format information system header.
#ifdef _AIX
# define __XCOFF32__
# define __XCOFF64__
# include <xcoff.h>
#else
# error "This source may be compiled only on AIX."
#endif
class cmXCOFFInternal
{
public:
// Construct and take ownership of the file stream object.
cmXCOFFInternal(cmXCOFF* external, std::unique_ptr<std::iostream> fin,
cmXCOFF::Mode mode)
: External(external)
, Stream(std::move(fin))
, Mode(mode)
{
}
// Destruct and delete the file stream object.
virtual ~cmXCOFFInternal() = default;
cmXCOFF::Mode GetMode() const { return this->Mode; }
virtual cm::optional<cm::string_view> GetLibPath() = 0;
virtual bool SetLibPath(cm::string_view libPath) = 0;
virtual bool RemoveLibPath() = 0;
protected:
// Data common to all ELF class implementations.
// The external cmXCOFF object.
cmXCOFF* External;
// The stream from which to read.
std::unique_ptr<std::iostream> Stream;
cmXCOFF::Mode Mode;
// Helper methods for subclasses.
void SetErrorMessage(const char* msg) { this->External->ErrorMessage = msg; }
};
namespace {
struct XCOFF32
{
using filehdr = struct filehdr;
using aouthdr = struct aouthdr;
using scnhdr = struct scnhdr;
using ldhdr = struct ldhdr;
static const std::size_t aouthdr_size = _AOUTHSZ_EXEC;
};
const unsigned char xcoff32_magic[] = { 0x01, 0xDF };
struct XCOFF64
{
using filehdr = struct filehdr_64;
using aouthdr = struct aouthdr_64;
using scnhdr = struct scnhdr_64;
using ldhdr = struct ldhdr_64;
static const std::size_t aouthdr_size = _AOUTHSZ_EXEC_64;
};
const unsigned char xcoff64_magic[] = { 0x01, 0xF7 };
template <typename XCOFF>
class Impl : public cmXCOFFInternal
{
static_assert(sizeof(typename XCOFF::aouthdr) == XCOFF::aouthdr_size,
"aouthdr structure size matches _AOUTHSZ_EXEC macro");
typename XCOFF::filehdr FileHeader;
typename XCOFF::aouthdr AuxHeader;
typename XCOFF::scnhdr LoaderSectionHeader;
typename XCOFF::ldhdr LoaderHeader;
std::streamoff LoaderImportFileTablePos = 0;
std::vector<char> LoaderImportFileTable;
bool Read(typename XCOFF::filehdr& x)
{
// FIXME: Add byte swapping if needed.
return static_cast<bool>(
this->Stream->read(reinterpret_cast<char*>(&x), sizeof(x)));
}
bool Read(typename XCOFF::aouthdr& x)
{
// FIXME: Add byte swapping if needed.
return static_cast<bool>(
this->Stream->read(reinterpret_cast<char*>(&x), sizeof(x)));
}
bool Read(typename XCOFF::scnhdr& x)
{
// FIXME: Add byte swapping if needed.
return static_cast<bool>(
this->Stream->read(reinterpret_cast<char*>(&x), sizeof(x)));
}
bool Read(typename XCOFF::ldhdr& x)
{
// FIXME: Add byte swapping if needed.
return static_cast<bool>(
this->Stream->read(reinterpret_cast<char*>(&x), sizeof(x)));
}
bool WriteLoaderImportFileTableLength(decltype(XCOFF::ldhdr::l_istlen) x)
{
// FIXME: Add byte swapping if needed.
return static_cast<bool>(
this->Stream->write(reinterpret_cast<char const*>(&x), sizeof(x)));
}
public:
Impl(cmXCOFF* external, std::unique_ptr<std::iostream> fin,
cmXCOFF::Mode mode);
cm::optional<cm::string_view> GetLibPath() override;
bool SetLibPath(cm::string_view libPath) override;
bool RemoveLibPath() override;
};
template <typename XCOFF>
Impl<XCOFF>::Impl(cmXCOFF* external, std::unique_ptr<std::iostream> fin,
cmXCOFF::Mode mode)
: cmXCOFFInternal(external, std::move(fin), mode)
{
if (!this->Read(this->FileHeader)) {
this->SetErrorMessage("Failed to read XCOFF file header.");
return;
}
if (this->FileHeader.f_opthdr != XCOFF::aouthdr_size) {
this->SetErrorMessage("XCOFF auxiliary header missing.");
return;
}
if (!this->Read(this->AuxHeader)) {
this->SetErrorMessage("Failed to read XCOFF auxiliary header.");
return;
}
if (this->AuxHeader.o_snloader == 0) {
this->SetErrorMessage("XCOFF loader section missing.");
return;
}
if (!this->Stream->seekg((this->AuxHeader.o_snloader - 1) *
sizeof(typename XCOFF::scnhdr),
std::ios::cur)) {
this->SetErrorMessage("Failed to seek to XCOFF loader section header.");
return;
}
if (!this->Read(this->LoaderSectionHeader)) {
this->SetErrorMessage("Failed to read XCOFF loader section header.");
return;
}
if ((this->LoaderSectionHeader.s_flags & STYP_LOADER) == 0) {
this->SetErrorMessage("XCOFF loader section header missing STYP_LOADER.");
return;
}
if (!this->Stream->seekg(this->LoaderSectionHeader.s_scnptr,
std::ios::beg)) {
this->SetErrorMessage("Failed to seek to XCOFF loader header.");
return;
}
if (!this->Read(this->LoaderHeader)) {
this->SetErrorMessage("Failed to read XCOFF loader header.");
return;
}
this->LoaderImportFileTablePos =
this->LoaderSectionHeader.s_scnptr + this->LoaderHeader.l_impoff;
if (!this->Stream->seekg(this->LoaderImportFileTablePos)) {
this->SetErrorMessage(
"Failed to seek to XCOFF loader import file id table.");
return;
}
this->LoaderImportFileTable.resize(this->LoaderHeader.l_istlen);
if (!this->Stream->read(this->LoaderImportFileTable.data(),
this->LoaderImportFileTable.size())) {
this->SetErrorMessage("Failed to read XCOFF loader import file id table.");
return;
}
}
template <typename XCOFF>
cm::optional<cm::string_view> Impl<XCOFF>::GetLibPath()
{
cm::optional<cm::string_view> result;
auto end = std::find(this->LoaderImportFileTable.begin(),
this->LoaderImportFileTable.end(), '\0');
if (end != this->LoaderImportFileTable.end()) {
result = cm::string_view(this->LoaderImportFileTable.data(),
end - this->LoaderImportFileTable.begin());
}
return result;
}
template <typename XCOFF>
bool Impl<XCOFF>::SetLibPath(cm::string_view libPath)
{
// The new LIBPATH must end in the standard AIX LIBPATH.
#define CM_AIX_LIBPATH "/usr/lib:/lib"
std::string libPathBuf;
if (libPath != CM_AIX_LIBPATH &&
!cmHasLiteralSuffix(libPath, ":" CM_AIX_LIBPATH)) {
libPathBuf = std::string(libPath);
if (!libPathBuf.empty() && libPathBuf.back() != ':') {
libPathBuf.push_back(':');
}
libPathBuf += CM_AIX_LIBPATH;
libPath = libPathBuf;
}
#undef CM_AIX_LIBPATH
auto oldEnd = std::find(this->LoaderImportFileTable.begin(),
this->LoaderImportFileTable.end(), '\0');
if (oldEnd == this->LoaderImportFileTable.end()) {
this->SetErrorMessage("XCOFF loader import file id table is invalid.");
return false;
}
if ((this->LoaderImportFileTable.begin() + libPath.size()) > oldEnd) {
this->SetErrorMessage("XCOFF loader import file id table is too small.");
return false;
}
{
std::vector<char> ift;
ift.reserve(this->LoaderImportFileTable.size());
// Start with the new LIBPATH.
ift.insert(ift.end(), libPath.begin(), libPath.end());
// Add the rest of the original table.
ift.insert(ift.end(), oldEnd, this->LoaderImportFileTable.end());
// If the new table is shorter, zero out the leftover space.
ift.resize(this->LoaderImportFileTable.size(), 0);
this->LoaderHeader.l_istlen =
static_cast<decltype(XCOFF::ldhdr::l_istlen)>(ift.size());
this->LoaderImportFileTable = std::move(ift);
}
if (!this->Stream->seekp(this->LoaderSectionHeader.s_scnptr +
offsetof(typename XCOFF::ldhdr, l_istlen),
std::ios::beg)) {
this->SetErrorMessage(
"Failed to seek to XCOFF loader header import file id table length.");
return false;
}
if (!this->WriteLoaderImportFileTableLength(this->LoaderHeader.l_istlen)) {
this->SetErrorMessage(
"Failed to write XCOFF loader header import file id table length.");
return false;
}
if (!this->Stream->seekp(this->LoaderImportFileTablePos, std::ios::beg)) {
this->SetErrorMessage(
"Failed to seek to XCOFF loader import file id table.");
return false;
}
if (!this->Stream->write(this->LoaderImportFileTable.data(),
this->LoaderImportFileTable.size())) {
this->SetErrorMessage(
"Failed to write XCOFF loader import file id table.");
return false;
}
return true;
}
template <typename XCOFF>
bool Impl<XCOFF>::RemoveLibPath()
{
return this->SetLibPath({});
}
}
//============================================================================
// External class implementation.
cmXCOFF::cmXCOFF(const char* fname, Mode mode)
{
// Try to open the file.
std::ios::openmode fmode = std::ios::in | std::ios::binary;
if (mode == Mode::ReadWrite) {
fmode |= std::ios::out;
}
auto f = cm::make_unique<cmsys::fstream>(fname, fmode);
// Quit now if the file could not be opened.
if (!f || !*f) {
this->ErrorMessage = "Error opening input file.";
return;
}
// Read the XCOFF magic number.
unsigned char magic[2];
if (!f->read(reinterpret_cast<char*>(magic), sizeof(magic))) {
this->ErrorMessage = "Error reading XCOFF magic number.";
return;
}
if (!f->seekg(0)) {
this->ErrorMessage = "Error seeking to beginning of file.";
return;
}
// Check the XCOFF type.
if (magic[0] == xcoff32_magic[0] && magic[1] == xcoff32_magic[1]) {
this->Internal = cm::make_unique<Impl<XCOFF32>>(this, std::move(f), mode);
} else if (magic[0] == xcoff64_magic[0] && magic[1] == xcoff64_magic[1]) {
this->Internal = cm::make_unique<Impl<XCOFF64>>(this, std::move(f), mode);
} else {
this->ErrorMessage = "File is not a XCOFF32 or XCOFF64 binary.";
}
}
cmXCOFF::~cmXCOFF() = default;
cmXCOFF::cmXCOFF(cmXCOFF&&) noexcept = default;
cmXCOFF& cmXCOFF::operator=(cmXCOFF&&) noexcept = default;
bool cmXCOFF::Valid() const
{
return this->Internal && this->ErrorMessage.empty();
}
cm::optional<cm::string_view> cmXCOFF::GetLibPath() const
{
cm::optional<cm::string_view> result;
if (this->Valid()) {
result = this->Internal->GetLibPath();
}
return result;
}
bool cmXCOFF::SetLibPath(cm::string_view libPath)
{
return this->Valid() && this->Internal->GetMode() == Mode::ReadWrite &&
this->Internal->SetLibPath(libPath);
}
bool cmXCOFF::RemoveLibPath()
{
return this->Valid() && this->Internal->GetMode() == Mode::ReadWrite &&
this->Internal->RemoveLibPath();
}