// descriptors.cc -- manage file descriptors for gold
-// Copyright 2008 Free Software Foundation, Inc.
+// Copyright (C) 2008-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
#include <cerrno>
+#include <cstdio>
#include <cstring>
#include <fcntl.h>
+#include <string>
#include <unistd.h>
+#include "debug.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
{
// adjusted downward if we run out of file descriptors.
Descriptors::Descriptors()
- : lock_(NULL), open_descriptors_(), stack_top_(-1), current_(0),
- limit_(8192 - 16)
+ : lock_(NULL), initialize_lock_(&this->lock_), open_descriptors_(),
+ stack_top_(-1), current_(0), limit_(8192 - 16)
{
this->open_descriptors_.reserve(128);
}
// 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.
- if (this->lock_ == NULL)
- {
- if (parameters->options_valid())
- this->lock_ = new Lock();
- else
- gold_assert(descriptor < 0);
- }
+ bool lock_initialized = this->initialize_lock_.initialize();
+
+ gold_assert(lock_initialized || descriptor < 0);
+
+ if (is_debugging_enabled(DEBUG_FILES))
+ this->limit_ = 8;
if (descriptor >= 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;
+ }
+ gold_debug(DEBUG_FILES, "Reused existing descriptor %d for \"%s\"",
+ descriptor, name);
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
{
Hold_lock hl(*this->lock_);
- gold_error(_("file %s was removed during the link"),
- this->open_descriptors_[descriptor].name);
+ gold_error(_("file %s was removed during the link"), name);
}
errno = ENOENT;
}
+ gold_debug(DEBUG_FILES, "Opened new descriptor %d for \"%s\"",
+ new_descriptor, name);
return new_descriptor;
}
if (new_descriptor >= 0)
{
- 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;
-
- ++this->current_;
- if (this->current_ >= this->limit_)
- this->close_some_descriptor();
-
- return new_descriptor;
+ // 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();
+
+ gold_debug(DEBUG_FILES, "Opened new descriptor %d for \"%s\"",
+ new_descriptor, name);
+ return new_descriptor;
+ }
}
// We ran out of file descriptors.
else
{
pod->inuse = false;
- if (!pod->is_write)
+ if (!pod->is_write && !pod->is_on_stack)
{
pod->stack_next = this->stack_top_;
this->stack_top_ = descriptor;
+ pod->is_on_stack = true;
}
}
+
+ gold_debug(DEBUG_FILES, "Released descriptor %d for \"%s\"",
+ descriptor, pod->name);
}
// Close some descriptor. The lock is held when this is called. We
if (::close(i) < 0)
gold_warning(_("while closing %s: %s"), pod->name, strerror(errno));
--this->current_;
+ gold_debug(DEBUG_FILES, "Closed descriptor %d for \"%s\"",
+ i, pod->name);
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;
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));
+ gold_debug(DEBUG_FILES, "Closed descriptor %d for \"%s\" (close_all)",
+ static_cast<int>(i), pod->name);
+ 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;
projects / deliverable / binutils-gdb.git / blobdiff