// fileread.cc -- read files for gold

// fileread.cc -- read files for gold

// Copyright (C) 2006-2024 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <[email protected]>.

// This file is part of gold.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#include "gold.h"

#include <cstring>
#include <cerrno>
#include <climits>
#include <fcntl.h>
#include <unistd.h>

#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif

#ifdef HAVE_READV
#include <sys/uio.h>
#endif

#include <sys/stat.h>
#include "filenames.h"

#include "debug.h"
#include "parameters.h"
#include "options.h"
#include "dirsearch.h"
#include "target.h"
#include "binary.h"
#include "descriptors.h"
#include "gold-threads.h"
#include "fileread.h"

// For systems without mmap support.
#ifndef HAVE_MMAP
# define mmap gold_mmap
# define munmap gold_munmap
# ifndef MAP_FAILED
# define MAP_FAILED (reinterpret_cast<void*>(-1))
# endif
# ifndef PROT_READ
# define PROT_READ 0
# endif
# ifndef MAP_PRIVATE
# define MAP_PRIVATE 0
# endif

# ifndef ENOSYS
# define ENOSYS EINVAL
# endif

static void *
gold_mmap(void *, size_t, int, int, int, off_t)
{
errno = ENOSYS;
return MAP_FAILED;
}

static int
gold_munmap(void *, size_t)
{
errno = ENOSYS;
return -1;
}

#endif

#ifndef HAVE_READV
struct iovec { void* iov_base; size_t iov_len; };
ssize_t
readv(int, const iovec*, int)
{
gold_unreachable();
}
#endif

namespace gold
{

// Get the last modified time of an unopened file.

bool
get_mtime(const char* filename, Timespec* mtime)
{
struct stat file_stat;

if (stat(filename, &file_stat) < 0)
return false;
#ifdef HAVE_STAT_ST_MTIM
mtime->seconds = file_stat.st_mtim.tv_sec;
mtime->nanoseconds = file_stat.st_mtim.tv_nsec;
#else
mtime->seconds = file_stat.st_mtime;
mtime->nanoseconds = 0;
#endif
return true;
}

// Class File_read.

// A lock for the File_read static variables.
static Lock* file_counts_lock = NULL;
static Initialize_lock file_counts_initialize_lock(&file_counts_lock);

// The File_read static variables.
unsigned long long File_read::total_mapped_bytes;
unsigned long long File_read::current_mapped_bytes;
unsigned long long File_read::maximum_mapped_bytes;
std::vector<std::string> File_read::files_read;

// Class File_read::View.

File_read::View::~View()
{
gold_assert(!this->is_locked());
switch (this->data_ownership_)
{
case DATA_ALLOCATED_ARRAY:
free(const_cast<unsigned char*>(this->data_));
break;
case DATA_MMAPPED:
if (::munmap(const_cast<unsigned char*>(this->data_), this->size_) != 0)
gold_warning(_("munmap failed: %s"), strerror(errno));
if (!parameters->options_valid() || parameters->options().stats())
{
file_counts_initialize_lock.initialize();
Hold_optional_lock hl(file_counts_lock);
File_read::current_mapped_bytes -= this->size_;
}
break;
case DATA_NOT_OWNED:
break;
default:
gold_unreachable();
}
}

void
File_read::View::lock()
{
++this->lock_count_;
}

void
File_read::View::unlock()
{
gold_assert(this->lock_count_ > 0);
--this->lock_count_;
}

bool
File_read::View::is_locked()
{
return this->lock_count_ > 0;
}

// Class File_read.

File_read::~File_read()
{
gold_assert(this->token_.is_writable());
if (this->is_descriptor_opened_)
{
release_descriptor(this->descriptor_, true);
this->descriptor_ = -1;
this->is_descriptor_opened_ = false;
}
this->name_.clear();
this->clear_views(CLEAR_VIEWS_ALL);
}

// Open the file.

bool
File_read::open(const Task* task, const std::string& name)
{
gold_assert(this->token_.is_writable()
&& this->descriptor_ < 0
&& !this->is_descriptor_opened_
&& this->name_.empty());
this->name_ = name;

this->descriptor_ = open_descriptor(-1, this->name_.c_str(),
O_RDONLY);

if (this->descriptor_ >= 0)
{
this->is_descriptor_opened_ = true;
struct stat s;
if (::fstat(this->descriptor_, &s) < 0)
gold_error(_("%s: fstat failed: %s"),
this->name_.c_str(), strerror(errno));
this->size_ = s.st_size;
gold_debug(DEBUG_FILES, "Attempt to open %s succeeded",
this->name_.c_str());
this->token_.add_writer(task);
file_counts_initialize_lock.initialize();
Hold_optional_lock hl(file_counts_lock);
record_file_read(this->name_);
}

return this->descriptor_ >= 0;
}

// Open the file with the contents in memory.

bool
File_read::open(const Task* task, const std::string& name,
const unsigned char* contents, off_t size)
{
gold_assert(this->token_.is_writable()
&& this->descriptor_ < 0
&& !this->is_descriptor_opened_
&& this->name_.empty());
this->name_ = name;
this->whole_file_view_ = new View(0, size, contents, 0, false,
View::DATA_NOT_OWNED);
this->add_view(this->whole_file_view_);
this->size_ = size;
this->token_.add_writer(task);
return true;
}

// Reopen a descriptor if necessary.

void
File_read::reopen_descriptor()
{
if (!this->is_descriptor_opened_)
{
this->descriptor_ = open_descriptor(this->descriptor_,
this->name_.c_str(),
O_RDONLY);
if (this->descriptor_ < 0)
gold_fatal(_("could not reopen file %s"), this->name_.c_str());
this->is_descriptor_opened_ = true;
}
}

// Release the file. This is called when we are done with the file in
// a Task.

void
File_read::release()
{
gold_assert(this->is_locked());

if (!parameters->options_valid() || parameters->options().stats())
{
file_counts_initialize_lock.initialize();
Hold_optional_lock hl(file_counts_lock);
File_read::total_mapped_bytes += this->mapped_bytes_;
File_read::current_mapped_bytes += this->mapped_bytes_;
if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes)
File_read::maximum_mapped_bytes = File_read::current_mapped_bytes;
}

this->mapped_bytes_ = 0;

// Only clear views if there is only one attached object. Otherwise
// we waste time trying to clear cached archive views. Similarly
// for releasing the descriptor.
if (this->object_count_ <= 1)
{
this->clear_views(CLEAR_VIEWS_NORMAL);
if (this->is_descriptor_opened_)
{
release_descriptor(this->descriptor_, false);
this->is_descriptor_opened_ = false;
}
}

this->released_ = true;
}

// Lock the file.

void
File_read::lock(const Task* task)
{
gold_assert(this->released_);
gold_debug(DEBUG_FILES, "Locking file \"%s\"", this->name_.c_str());
this->token_.add_writer(task);
this->released_ = false;
}

// Unlock the file.

void
File_read::unlock(const Task* task)
{
gold_debug(DEBUG_FILES, "Unlocking file \"%s\"", this->name_.c_str());
this->release();
this->token_.remove_writer(task);
}

// Return whether the file is locked.

bool
File_read::is_locked() const
{
if (!this->token_.is_writable())
return true;
// The file is not locked, so it should have been released.
gold_assert(this->released_);
return false;
}

// See if we have a view which covers the file starting at START for
// SIZE bytes. Return a pointer to the View if found, NULL if not.
// If BYTESHIFT is not -1U, the returned View must have the specified
// byte shift; otherwise, it may have any byte shift. If VSHIFTED is
// not NULL, this sets *VSHIFTED to a view which would have worked if
// not for the requested BYTESHIFT.

inline File_read::View*
File_read::find_view(off_t start, section_size_type size,
unsigned int byteshift, File_read::View** vshifted) const
{
gold_assert(start <= this->size_
&& (static_cast<unsigned long long>(size)
<= static_cast<unsigned long long>(this->size_ - start)));

if (vshifted != NULL)
*vshifted = NULL;

// If we have the whole file mmapped, and the alignment is right,
// we can return it.
if (this->whole_file_view_)
if (byteshift == -1U || byteshift == 0)
return this->whole_file_view_;

off_t page = File_read::page_offset(start);

unsigned int bszero = 0;
Views::const_iterator p = this->views_.upper_bound(std::make_pair(page - 1,
bszero));

while (p != this->views_.end() && p->first.first <= page)
{
if (p->second->start() <= start
&& (p->second->start() + static_cast<off_t>(p->second->size())
>= start + static_cast<off_t>(size)))
{
if (byteshift == -1U || byteshift == p->second->byteshift())
{
p->second->set_accessed();
return p->second;
}

if (vshifted != NULL && *vshifted == NULL)
*vshifted = p->second;
}

++p;
}

return NULL;
}

// Read SIZE bytes from the file starting at offset START. Read into
// the buffer at P.

void
File_read::do_read(off_t start, section_size_type size, void* p)
{
ssize_t bytes;
if (this->whole_file_view_ != NULL)
{
// See PR 23765 for an example of a testcase that triggers this error.
if (((ssize_t) start) < 0)
gold_fatal(_("%s: read failed, starting offset (%#llx) less than zero"),
this->filename().c_str(),
static_cast<long long>(start));

bytes = this->size_ - start;
if (static_cast<section_size_type>(bytes) >= size)
{
memcpy(p, this->whole_file_view_->data() + start, size);
return;
}
}
else
{
this->reopen_descriptor();

char *read_ptr = static_cast<char *>(p);
off_t read_pos = start;
size_t to_read = size;
do
{
bytes = ::pread(this->descriptor_, read_ptr, to_read, read_pos);
if (bytes < 0)
gold_fatal(_("%s: pread failed: %s"),
this->filename().c_str(), strerror(errno));

read_pos += bytes;
read_ptr += bytes;
to_read -= bytes;
if (to_read == 0)
return;
}
while (bytes > 0);

bytes = size - to_read;
}

gold_fatal(_("%s: file too short: read only %lld of %lld bytes at %lld"),
this->filename().c_str(),
static_cast<long long>(bytes),
static_cast<long long>(size),
static_cast<long long>(start));
}

// Read data from the file.

void
File_read::read(off_t start, section_size_type size, void* p)
{
const File_read::View* pv = this->find_view(start, size, -1U, NULL);
if (pv != NULL)
{
memcpy(p, pv->data() + (start - pv->start() + pv->byteshift()), size);
return;
}

this->do_read(start, size, p);
}

// Add a new view. There may already be an existing view at this
// offset. If there is, the new view will be larger, and should
// replace the old view.

void
File_read::add_view(File_read::View* v)
{
std::pair<Views::iterator, bool> ins =
this->views_.insert(std::make_pair(std::make_pair(v->start(),
v->byteshift()),
v));
if (ins.second)
return;

// There was an existing view at this offset. It must not be large
// enough. We can't delete it here, since something might be using
// it; we put it on a list to be deleted when the file is unlocked.
File_read::View* vold = ins.first->second;
gold_assert(vold->size() < v->size());
if (vold->should_cache())
{
v->set_cache();
vold->clear_cache();
}
this->saved_views_.push_back(vold);

ins.first->second = v;
}

// Make a new view with a specified byteshift, reading the data from
// the file.

File_read::View*
File_read::make_view(off_t start, section_size_type size,
unsigned int byteshift, bool cache)
{
gold_assert(size > 0);
gold_assert(start <= this->size_
&& (static_cast<unsigned long long>(size)
<= static_cast<unsigned long long>(this->size_ - start)));

off_t poff = File_read::page_offset(start);

section_size_type psize = File_read::pages(size + (start - poff));

if (poff + static_cast<off_t>(psize) >= this->size_)
{
psize = this->size_ - poff;
gold_assert(psize >= size);
}

void* p;
View::Data_ownership ownership;
if (byteshift != 0)
{
p = malloc(psize + byteshift);
if (p == NULL)
gold_nomem();
memset(p, 0, byteshift);
this->do_read(poff, psize, static_cast<unsigned char*>(p) + byteshift);
ownership = View::DATA_ALLOCATED_ARRAY;
}
else
{
this->reopen_descriptor();
p = ::mmap(NULL, psize, PROT_READ, MAP_PRIVATE, this->descriptor_, poff);
if (p != MAP_FAILED)
{
ownership = View::DATA_MMAPPED;
this->mapped_bytes_ += psize;
}
else
{
p = malloc(psize);
if (p == NULL)
gold_nomem();
this->do_read(poff, psize, p);
ownership = View::DATA_ALLOCATED_ARRAY;
}
}

const unsigned char* pbytes = static_cast<const unsigned char*>(p);
File_read::View* v = new File_read::View(poff, psize, pbytes, byteshift,
cache, ownership);

this->add_view(v);

return v;
}

// Find a View or make a new one, shifted as required by the file
// offset OFFSET and ALIGNED.

File_read::View*
File_read::find_or_make_view(off_t offset, off_t start,
section_size_type size, bool aligned, bool cache)
{
// Check that start and end of the view are within the file.
if (start > this->size_
|| (static_cast<unsigned long long>(size)
> static_cast<unsigned long long>(this->size_ - start)))
gold_fatal(_("%s: attempt to map %lld bytes at offset %lld exceeds "
"size of file; the file may be corrupt"),
this->filename().c_str(),
static_cast<long long>(size),
static_cast<long long>(start));

unsigned int byteshift;
if (offset == 0)
byteshift = 0;
else
{
unsigned int target_size = (!parameters->target_valid()
? 64
: parameters->target().get_size());
byteshift = offset & ((target_size / 8) - 1);

// Set BYTESHIFT to the number of dummy bytes which must be
// inserted before the data in order for this data to be
// aligned.
if (byteshift != 0)
byteshift = (target_size / 8) - byteshift;
}

// If --map-whole-files is set, make sure we have a
// whole file view. Options may not yet be ready, e.g.,
// when reading a version script. We then default to
// --no-map-whole-files.
if (this->whole_file_view_ == NULL
&& parameters->options_valid()
&& parameters->options().map_whole_files())
this->whole_file_view_ = this->make_view(0, this->size_, 0, cache);

// Try to find a View with the required BYTESHIFT.
File_read::View* vshifted;
File_read::View* v = this->find_view(offset + start, size,
aligned ? byteshift : -1U,
&vshifted);
if (v != NULL)
{
if (cache)
v->set_cache();
return v;
}

// If VSHIFTED is not NULL, then it has the data we need, but with
// the wrong byteshift.
v = vshifted;
if (v != NULL)
{
gold_assert(aligned);

unsigned char* pbytes;
pbytes = static_cast<unsigned char*>(malloc(v->size() + byteshift));
if (pbytes == NULL)
gold_nomem();
memset(pbytes, 0, byteshift);
memcpy(pbytes + byteshift, v->data() + v->byteshift(), v->size());

File_read::View* shifted_view =
new File_read::View(v->start(), v->size(), pbytes, byteshift,
cache, View::DATA_ALLOCATED_ARRAY);

this->add_view(shifted_view);
return shifted_view;
}

// Make a new view. If we don't need an aligned view, use a
// byteshift of 0, so that we can use mmap.
return this->make_view(offset + start, size,
aligned ? byteshift : 0,
cache);
}

// Get a view into the file.

const unsigned char*
File_read::get_view(off_t offset, off_t start, section_size_type size,
bool aligned, bool cache)
{
File_read::View* pv = this->find_or_make_view(offset, start, size,
aligned, cache);
return pv->data() + (offset + start - pv->start() + pv->byteshift());
}

File_view*
File_read::get_lasting_view(off_t offset, off_t start, section_size_type size,
bool aligned, bool cache)
{
File_read::View* pv = this->find_or_make_view(offset, start, size,
aligned, cache);
pv->lock();
return new File_view(*this, pv,
(pv->data()
+ (offset + start - pv->start() + pv->byteshift())));
}

// Use readv to read COUNT entries from RM starting at START. BASE
// must be added to all file offsets in RM.

void
File_read::do_readv(off_t base, const Read_multiple& rm, size_t start,
size_t count)
{
unsigned char discard[File_read::page_size];
iovec iov[File_read::max_readv_entries * 2];
size_t iov_index = 0;

off_t first_offset = rm[start].file_offset;
off_t last_offset = first_offset;
ssize_t want = 0;
for (size_t i = 0; i < count; ++i)
{
const Read_multiple_entry& i_entry(rm[start + i]);

if (i_entry.file_offset > last_offset)
{
size_t skip = i_entry.file_offset - last_offset;
gold_assert(skip <= sizeof discard);

iov[iov_index].iov_base = discard;
iov[iov_index].iov_len = skip;
++iov_index;

want += skip;
}

iov[iov_index].iov_base = i_entry.buffer;
iov[iov_index].iov_len = i_entry.size;
++iov_index;

want += i_entry.size;

last_offset = i_entry.file_offset + i_entry.size;
}

this->reopen_descriptor();

gold_assert(iov_index < sizeof iov / sizeof iov[0]);

if (::lseek(this->descriptor_, base + first_offset, SEEK_SET) < 0)
gold_fatal(_("%s: lseek failed: %s"),
this->filename().c_str(), strerror(errno));

ssize_t got = ::readv(this->descriptor_, iov, iov_index);

if (got < 0)
gold_fatal(_("%s: readv failed: %s"),
this->filename().c_str(), strerror(errno));
if (got != want)
gold_fatal(_("%s: file too short: read only %zd of %zd bytes at %lld"),
this->filename().c_str(),
got, want, static_cast<long long>(base + first_offset));
}

// Portable IOV_MAX.

#if !defined(HAVE_READV)
#define GOLD_IOV_MAX 1
#elif defined(IOV_MAX)
#define GOLD_IOV_MAX IOV_MAX
#else
#define GOLD_IOV_MAX (File_read::max_readv_entries * 2)
#endif

// Read several pieces of data from the file.

void
File_read::read_multiple(off_t base, const Read_multiple& rm)
{
static size_t iov_max = GOLD_IOV_MAX;
size_t count = rm.size();
size_t i = 0;
while (i < count)
{
// Find up to MAX_READV_ENTRIES consecutive entries which are
// less than one page apart.
const Read_multiple_entry& i_entry(rm[i]);
off_t i_off = i_entry.file_offset;
off_t end_off = i_off + i_entry.size;
size_t j;
for (j = i + 1; j < count; ++j)
{
if (j - i >= File_read::max_readv_entries || j - i >= iov_max / 2)
break;
const Read_multiple_entry& j_entry(rm[j]);
off_t j_off = j_entry.file_offset;
gold_assert(j_off >= end_off);
off_t j_end_off = j_off + j_entry.size;
if (j_end_off - end_off >= File_read::page_size)
break;
end_off = j_end_off;
}

if (j == i + 1)
this->read(base + i_off, i_entry.size, i_entry.buffer);
else
{
File_read::View* view = this->find_view(base + i_off,
end_off - i_off,
-1U, NULL);
if (view == NULL)
this->do_readv(base, rm, i, j - i);
else
{
const unsigned char* v = (view->data()
+ (base + i_off - view->start()
+ view->byteshift()));
for (size_t k = i; k < j; ++k)
{
const Read_multiple_entry& k_entry(rm[k]);
gold_assert((convert_to_section_size_type(k_entry.file_offset
- i_off)
+ k_entry.size)
<= convert_to_section_size_type(end_off
- i_off));
memcpy(k_entry.buffer,
v + (k_entry.file_offset - i_off),
k_entry.size);
}
}
}

i = j;
}
}

// Mark all views as no longer cached.

void
File_read::clear_view_cache_marks()
{
// Just ignore this if there are multiple objects associated with
// the file. Otherwise we will wind up uncaching and freeing some
// views for other objects.
if (this->object_count_ > 1)
return;

for (Views::iterator p = this->views_.begin();
p != this->views_.end();
++p)
p->second->clear_cache();
for (Saved_views::iterator p = this->saved_views_.begin();
p != this->saved_views_.end();
++p)
(*p)->clear_cache();
}

// Remove all the file views. For a file which has multiple
// associated objects (i.e., an archive), we keep accessed views
// around until next time, in the hopes that they will be useful for
// the next object.

void
File_read::clear_views(Clear_views_mode mode)
{
bool keep_files_mapped = (parameters->options_valid()
&& parameters->options().keep_files_mapped());
Views::iterator p = this->views_.begin();
while (p != this->views_.end())
{
bool should_delete;
if (p->second->is_locked() || p->second->is_permanent_view())
should_delete = false;
else if (mode == CLEAR_VIEWS_ALL)
should_delete = true;
else if ((p->second->should_cache()
|| p->second == this->whole_file_view_)
&& keep_files_mapped)
should_delete = false;
else if (this->object_count_ > 1
&& p->second->accessed()
&& mode != CLEAR_VIEWS_ARCHIVE)
should_delete = false;
else
should_delete = true;

if (should_delete)
{
if (p->second == this->whole_file_view_)
this->whole_file_view_ = NULL;
delete p->second;

// map::erase invalidates only the iterator to the deleted
// element.
Views::iterator pe = p;
++p;
this->views_.erase(pe);
}
else
{
p->second->clear_accessed();
++p;
}
}

Saved_views::iterator q = this->saved_views_.begin();
while (q != this->saved_views_.end())
{
if (!(*q)->is_locked())
{
delete *q;
q = this->saved_views_.erase(q);
}
else
{
gold_assert(mode != CLEAR_VIEWS_ALL);
++q;
}
}
}

// Print statistical information to stderr. This is used for --stats.

void
File_read::print_stats()
{
fprintf(stderr, _("%s: total bytes mapped for read: %llu\n"),
program_name, File_read::total_mapped_bytes);
fprintf(stderr, _("%s: maximum bytes mapped for read at one time: %llu\n"),
program_name, File_read::maximum_mapped_bytes);
}

// Class File_view.

File_view::~File_view()
{
gold_assert(this->file_.is_locked());
this->view_->unlock();
}

// Class Input_file.

// Create a file given just the filename.

Input_file::Input_file(const char* name)
: found_name_(), file_(), is_in_sysroot_(false), format_(FORMAT_NONE)
{
this->input_argument_ =
new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
"", false, Position_dependent_options());
}

// Create a file for testing.

Input_file::Input_file(const Task* task, const char* name,
const unsigned char* contents, off_t size)
: file_()
{
this->input_argument_ =
new Input_file_argument(name, Input_file_argument::INPUT_FILE_TYPE_FILE,
"", false, Position_dependent_options());
bool ok = this->file_.open(task, name, contents, size);
gold_assert(ok);
}

// Return the position dependent options in force for this file.

const Position_dependent_options&
Input_file::options() const
{
return this->input_argument_->options();
}

// Return the name given by the user. For -lc this will return "c".

const char*
Input_file::name() const
{
return this->input_argument_->name();
}

// Return whether this file is in a system directory.

bool
Input_file::is_in_system_directory() const
{
if (this->is_in_sysroot())
return true;
return parameters->options().is_in_system_directory(this->filename());
}

// Return whether we are only reading symbols.

bool
Input_file::just_symbols() const
{
return this->input_argument_->just_symbols();
}

// Return whether this is a file that we will search for in the list
// of directories.

bool
Input_file::will_search_for() const
{
return (!IS_ABSOLUTE_PATH(this->input_argument_->name())
&& (this->input_argument_->is_lib()
|| this->input_argument_->is_searched_file()
|| this->input_argument_->extra_search_path() != NULL));
}

// Return the file last modification time. Calls gold_fatal if the stat
// system call failed.

Timespec
File_read::get_mtime()
{
struct stat file_stat;
this->reopen_descriptor();

if (fstat(this->descriptor_, &file_stat) < 0)
gold_fatal(_("%s: stat failed: %s"), this->name_.c_str(),
strerror(errno));
#ifdef HAVE_STAT_ST_MTIM
return Timespec(file_stat.st_mtim.tv_sec, file_stat.st_mtim.tv_nsec);
#else
return Timespec(file_stat.st_mtime, 0);
#endif
}

// Try to find a file in the extra search dirs. Returns true on success.

bool
Input_file::try_extra_search_path(int* pindex,
const Input_file_argument* input_argument,
std::string filename, std::string* found_name,
std::string* namep)
{
if (input_argument->extra_search_path() == NULL)
return false;

std::string name = input_argument->extra_search_path();
if (!IS_DIR_SEPARATOR(name[name.length() - 1]))
name += '/';
name += filename;

struct stat dummy_stat;
if (*pindex > 0 || ::stat(name.c_str(), &dummy_stat) < 0)
return false;

*found_name = filename;
*namep = name;
return true;
}

// Find the actual file.
// If the filename is not absolute, we assume it is in the current
// directory *except* when:
// A) input_argument_->is_lib() is true;
// B) input_argument_->is_searched_file() is true; or
// C) input_argument_->extra_search_path() is not empty.
// In each, we look in extra_search_path + library_path to find
// the file location, rather than the current directory.

bool
Input_file::find_file(const Dirsearch& dirpath, int* pindex,
const Input_file_argument* input_argument,
bool* is_in_sysroot,
std::string* found_name, std::string* namep)
{
std::string name;

// Case 1: name is an absolute file, just try to open it
// Case 2: name is relative but is_lib is false, is_searched_file is false,
// and extra_search_path is empty
if (IS_ABSOLUTE_PATH(input_argument->name())
|| (!input_argument->is_lib()
&& !input_argument->is_searched_file()
&& input_argument->extra_search_path() == NULL))
{
name = input_argument->name();
*found_name = name;
*namep = name;
return true;
}
// Case 3: is_lib is true or is_searched_file is true
else if (input_argument->is_lib()
|| input_argument->is_searched_file())
{
std::vector<std::string> names;
names.reserve(2);
if (input_argument->is_lib())
{
std::string prefix = "lib";
prefix += input_argument->name();
if (parameters->options().is_static()
|| !input_argument->options().Bdynamic())
names.push_back(prefix + ".a");
else
{
names.push_back(prefix + ".so");
names.push_back(prefix + ".a");
}
}
else
names.push_back(input_argument->name());

for (std::vector<std::string>::const_iterator n = names.begin();
n != names.end();
++n)
if (Input_file::try_extra_search_path(pindex, input_argument, *n,
found_name, namep))
return true;

// It is not in the extra_search_path.
name = dirpath.find(names, is_in_sysroot, pindex, found_name);
if (name.empty())
{
gold_error(_("cannot find %s%s"),
input_argument->is_lib() ? "-l" : "",
input_argument->name());
return false;
}
*namep = name;
return true;
}
// Case 4: extra_search_path is not empty
else
{
gold_assert(input_argument->extra_search_path() != NULL);

if (try_extra_search_path(pindex, input_argument, input_argument->name(),
found_name, namep))
return true;

// extra_search_path failed, so check the normal search-path.
int index = *pindex;
if (index > 0)
--index;
name = dirpath.find(std::vector<std::string>(1, input_argument->name()),
is_in_sysroot, &index, found_name);
if (name.empty())
{
gold_error(_("cannot find %s"),
input_argument->name());
return false;
}
*namep = name;
*pindex = index + 1;
return true;
}
}

// Open the file.

bool
Input_file::open(const Dirsearch& dirpath, const Task* task, int* pindex)
{
std::string name;
if (!Input_file::find_file(dirpath, pindex, this->input_argument_,
&this->is_in_sysroot_, &this->found_name_, &name))
return false;

// Now that we've figured out where the file lives, try to open it.

General_options::Object_format format =
this->input_argument_->options().format_enum();
bool ok;
if (format == General_options::OBJECT_FORMAT_ELF)
{
ok = this->file_.open(task, name);
this->format_ = FORMAT_ELF;
}
else
{
gold_assert(format == General_options::OBJECT_FORMAT_BINARY);
ok = this->open_binary(task, name);
this->format_ = FORMAT_BINARY;
}

if (!ok)
{
gold_error(_("cannot open %s: %s"),
name.c_str(), strerror(errno));
this->format_ = FORMAT_NONE;
return false;
}

return true;
}

// Open a file for --format binary.

bool
Input_file::open_binary(const Task* task, const std::string& name)
{
// In order to open a binary file, we need machine code, size, and
// endianness. We may not have a valid target at this point, in
// which case we use the default target.
parameters_force_valid_target();
const Target& target(parameters->target());

Binary_to_elf binary_to_elf(target.machine_code(),
target.get_size(),
target.is_big_endian(),
name);
if (!binary_to_elf.convert(task))
return false;
return this->file_.open(task, name, binary_to_elf.converted_data_leak(),
binary_to_elf.converted_size());
}

void
File_read::record_file_read(const std::string& name)
{
File_read::files_read.push_back(name);
}

void
File_read::write_dependency_file(const char* dependency_file_name,
const char* output_file_name)
{
FILE *depfile = fopen(dependency_file_name, "w");

fprintf(depfile, "%s:", output_file_name);
for (std::vector<std::string>::const_iterator it = files_read.begin();
it != files_read.end();
++it)
fprintf(depfile, " \\\n %s", it->c_str());
fprintf(depfile, "\n");

for (std::vector<std::string>::const_iterator it = files_read.begin();
it != files_read.end();
++it)
fprintf(depfile, "\n%s:\n", it->c_str());

fclose(depfile);
}

} // End namespace gold.