1 files changed, 280 insertions, 0 deletions
diff --git a/binutils-2.25/gold/descriptors.cc b/binutils-2.25/gold/descriptors.cc
new file mode 100644
index 00000000..b7fbaa61
--- /dev/null
+++ b/binutils-2.25/gold/descriptors.cc
@@ -0,0 +1,280 @@
+// descriptors.cc -- manage file descriptors for gold
+
+// Copyright 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// 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 <cerrno>
+#include <cstdio>
+#include <cstring>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "parameters.h"
+#include "options.h"
+#include "gold-threads.h"
+#include "descriptors.h"
+#include "binary-io.h"
+
+// O_CLOEXEC is only available on newer systems.
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+
+// Very old systems may not define FD_CLOEXEC.
+#ifndef FD_CLOEXEC
+#define FD_CLOEXEC 1
+#endif
+
+static inline void
+set_close_on_exec(int fd ATTRIBUTE_UNUSED)
+{
+// Mingw does not define F_SETFD.
+#ifdef F_SETFD
+  fcntl(fd, F_SETFD, FD_CLOEXEC);
+#endif
+}
+
+namespace gold
+{
+
+// Class Descriptors.
+
+// The default for limit_ is meant to simply be large.  It gets
+// adjusted downward if we run out of file descriptors.
+
+Descriptors::Descriptors()
+  : lock_(NULL), initialize_lock_(&this->lock_), open_descriptors_(),
+    stack_top_(-1), current_(0), limit_(8192 - 16)
+{
+  this->open_descriptors_.reserve(128);
+}
+
+// Open a file.
+
+int
+Descriptors::open(int descriptor, const char* name, int flags, int mode)
+{
+  // We don't initialize this until we are called, because we can't
+  // initialize a Lock until we have parsed the options to find out
+  // whether we are running with threads.  We can be called before
+  // options are valid when reading a linker script.
+  bool lock_initialized = this->initialize_lock_.initialize();
+
+  gold_assert(lock_initialized || descriptor < 0);
+
+  if (descriptor >= 0)
+    {
+      Hold_lock hl(*this->lock_);
+
+      gold_assert(static_cast<size_t>(descriptor)
+		  < this->open_descriptors_.size());
+      Open_descriptor* pod = &this->open_descriptors_[descriptor];
+      if (pod->name == name
+	  || (pod->name != NULL && strcmp(pod->name, name) == 0))
+	{
+	  gold_assert(!pod->inuse);
+	  pod->inuse = true;
+	  if (descriptor == this->stack_top_)
+	    {
+	      this->stack_top_ = pod->stack_next;
+	      pod->stack_next = -1;
+	      pod->is_on_stack = false;
+	    }
+	  return descriptor;
+	}
+    }
+
+  while (true)
+    {
+      // We always want to set the close-on-exec flag; we don't
+      // require callers to pass it.
+      flags |= O_CLOEXEC;
+
+      // Always open the file as a binary file.
+      flags |= O_BINARY;
+
+      int new_descriptor = ::open(name, flags, mode);
+      if (new_descriptor < 0
+	  && errno != ENFILE
+	  && errno != EMFILE)
+	{
+	  if (descriptor >= 0 && errno == ENOENT)
+	    {
+	      {
+		Hold_lock hl(*this->lock_);
+
+		gold_error(_("file %s was removed during the link"), name);
+	      }
+
+	      errno = ENOENT;
+	    }
+
+	  return new_descriptor;
+	}
+
+      if (new_descriptor >= 0)
+	{
+	  // If we have any plugins, we really do need to set the
+	  // close-on-exec flag, even if O_CLOEXEC is not defined.
+	  // FIXME: In some cases O_CLOEXEC may be defined in the
+	  // header file but not supported by the kernel.
+	  // Unfortunately there doesn't seem to be any obvious way to
+	  // detect that, as unknown flags passed to open are ignored.
+	  if (O_CLOEXEC == 0
+	      && parameters->options_valid()
+	      && parameters->options().has_plugins())
+	    set_close_on_exec(new_descriptor);
+
+	  {
+	    Hold_optional_lock hl(this->lock_);
+
+	    if (static_cast<size_t>(new_descriptor)
+		>= this->open_descriptors_.size())
+	      this->open_descriptors_.resize(new_descriptor + 64);
+
+	    Open_descriptor* pod = &this->open_descriptors_[new_descriptor];
+	    pod->name = name;
+	    pod->stack_next = -1;
+	    pod->inuse = true;
+	    pod->is_write = (flags & O_ACCMODE) != O_RDONLY;
+	    pod->is_on_stack = false;
+
+	    ++this->current_;
+	    if (this->current_ >= this->limit_)
+	      this->close_some_descriptor();
+
+	    return new_descriptor;
+	  }
+	}
+
+      // We ran out of file descriptors.
+      {
+	Hold_optional_lock hl(this->lock_);
+
+	this->limit_ = this->current_ - 16;
+	if (this->limit_ < 8)
+	  this->limit_ = 8;
+	if (!this->close_some_descriptor())
+	  gold_fatal(_("out of file descriptors and couldn't close any"));
+      }
+    }
+}
+
+// Release a descriptor.
+
+void
+Descriptors::release(int descriptor, bool permanent)
+{
+  Hold_optional_lock hl(this->lock_);
+
+  gold_assert(descriptor >= 0
+	      && (static_cast<size_t>(descriptor)
+		  < this->open_descriptors_.size()));
+  Open_descriptor* pod = &this->open_descriptors_[descriptor];
+
+  if (permanent
+      || (this->current_ > this->limit_ && !pod->is_write))
+    {
+      if (::close(descriptor) < 0)
+	gold_warning(_("while closing %s: %s"), pod->name, strerror(errno));
+      pod->name = NULL;
+      --this->current_;
+    }
+  else
+    {
+      pod->inuse = false;
+      if (!pod->is_write && !pod->is_on_stack)
+	{
+	  pod->stack_next = this->stack_top_;
+	  this->stack_top_ = descriptor;
+	  pod->is_on_stack = true;
+	}
+    }
+}
+
+// Close some descriptor.  The lock is held when this is called.  We
+// close the descriptor on the top of the free stack.  Note that this
+// is the opposite of an LRU algorithm--we close the most recently
+// used descriptor.  That is because the linker tends to cycle through
+// all the files; after we release a file, we are unlikely to need it
+// again until we have looked at all the other files.  Return true if
+// we closed a descriptor.
+
+bool
+Descriptors::close_some_descriptor()
+{
+  int last = -1;
+  int i = this->stack_top_;
+  while (i >= 0)
+    {
+      gold_assert(static_cast<size_t>(i) < this->open_descriptors_.size());
+      Open_descriptor* pod = &this->open_descriptors_[i];
+      if (!pod->inuse && !pod->is_write)
+	{
+	  if (::close(i) < 0)
+	    gold_warning(_("while closing %s: %s"), pod->name, strerror(errno));
+	  --this->current_;
+	  pod->name = NULL;
+	  if (last < 0)
+	    this->stack_top_ = pod->stack_next;
+	  else
+	    this->open_descriptors_[last].stack_next = pod->stack_next;
+	  pod->stack_next = -1;
+	  pod->is_on_stack = false;
+	  return true;
+	}
+      last = i;
+      i = pod->stack_next;
+    }
+
+  // We couldn't find any descriptors to close.  This is weird but not
+  // necessarily an error.
+  return false;
+}
+
+// Close all the descriptors open for reading.
+
+void
+Descriptors::close_all()
+{
+  Hold_optional_lock hl(this->lock_);
+
+  for (size_t i = 0; i < this->open_descriptors_.size(); i++)
+    {
+      Open_descriptor* pod = &this->open_descriptors_[i];
+      if (pod->name != NULL && !pod->inuse && !pod->is_write)
+	{
+	  if (::close(i) < 0)
+	    gold_warning(_("while closing %s: %s"), pod->name, strerror(errno));
+	  pod->name = NULL;
+	  pod->stack_next = -1;
+	  pod->is_on_stack = false;
+	}
+    }
+  this->stack_top_ = -1;
+}
+
+// The single global variable which manages descriptors.
+
+Descriptors descriptors;
+
+} // End namespace gold.