// fileread.h -- read files for gold -*- C++ -*-
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
namespace gold
{
+// Since not all system supports stat.st_mtim and struct timespec,
+// we define our own structure and fill the nanoseconds if we can.
+
+struct Timespec
+{
+ Timespec()
+ : seconds(0), nanoseconds(0)
+ { }
+
+ Timespec(time_t a_seconds, int a_nanoseconds)
+ : seconds(a_seconds), nanoseconds(a_nanoseconds)
+ { }
+
+ time_t seconds;
+ int nanoseconds;
+};
+
+// Get the last modified time of an unopened file. Returns false if the
+// file does not exist.
+
+bool
+get_mtime(const char* filename, Timespec* mtime);
+
class Position_dependent_options;
class Input_file_argument;
class Dirsearch;
class File_view;
-// File_read manages a file descriptor for a file we are reading. We
-// close file descriptors if we run out of them, so this class reopens
-// the file as needed.
+// File_read manages a file descriptor and mappings for a file we are
+// reading.
class File_read
{
public:
File_read()
- : name_(), descriptor_(-1), object_count_(0), size_(0), token_(false),
- views_(), saved_views_(), contents_(NULL), mapped_bytes_(0),
- released_(true)
+ : name_(), descriptor_(-1), is_descriptor_opened_(false), object_count_(0),
+ size_(0), token_(false), views_(), saved_views_(), mapped_bytes_(0),
+ released_(true), whole_file_view_(NULL)
{ }
~File_read();
{ --this->object_count_; }
// Lock the file for exclusive access within a particular Task::run
- // execution. This means that the descriptor can not be closed.
- // This routine may only be called when the workqueue lock is held.
+ // execution. This routine may only be called when the workqueue
+ // lock is held.
void
lock(const Task* t);
- // Unlock the descriptor, permitting it to be closed if necessary.
+ // Unlock the file.
void
unlock(const Task* t);
{ return this->size_; }
// Return a view into the file starting at file offset START for
- // SIZE bytes. The pointer will remain valid until the File_read is
- // unlocked. It is an error if we can not read enough data from the
- // file. The CACHE parameter is a hint as to whether it will be
- // useful to cache this data for later accesses--i.e., later calls
- // to get_view, read, or get_lasting_view which retrieve the same
+ // SIZE bytes. OFFSET is the offset into the input file for the
+ // file we are reading; this is zero for a normal object file,
+ // non-zero for an object file in an archive. ALIGNED is true if
+ // the data must be naturally aligned (i.e., aligned to the size
+ // of a target word); this only matters when OFFSET is not zero.
+ // The pointer will remain valid until the File_read is unlocked.
+ // It is an error if we can not read enough data from the file.
+ // The CACHE parameter is a hint as to whether it will be useful
+ // to cache this data for later accesses--i.e., later calls to
+ // get_view, read, or get_lasting_view which retrieve the same
// data.
const unsigned char*
- get_view(off_t start, section_size_type size, bool cache);
+ get_view(off_t offset, off_t start, section_size_type size, bool aligned,
+ bool cache);
// Read data from the file into the buffer P starting at file offset
// START for SIZE bytes.
void
- read(off_t start, section_size_type size, void* p) const;
+ read(off_t start, section_size_type size, void* p);
// Return a lasting view into the file starting at file offset START
// for SIZE bytes. This is allocated with new, and the caller is
// responsible for deleting it when done. The data associated with
// this view will remain valid until the view is deleted. It is an
- // error if we can not read enough data from the file. The CACHE
- // parameter is as in get_view.
+ // error if we can not read enough data from the file. The OFFSET,
+ // ALIGNED and CACHE parameters are as in get_view.
File_view*
- get_lasting_view(off_t start, section_size_type size, bool cache);
+ get_lasting_view(off_t offset, off_t start, section_size_type size,
+ bool aligned, bool cache);
// Mark all views as no longer cached.
void
clear_view_cache_marks();
+ // Discard all uncached views. This is normally done by release(),
+ // but not for objects in archives. FIXME: This is a complicated
+ // interface, and it would be nice to have something more automatic.
+ void
+ clear_uncached_views()
+ { this->clear_views(CLEAR_VIEWS_ARCHIVE); }
+
// A struct used to do a multiple read.
struct Read_multiple_entry
{
static void
print_stats();
+ // Return the open file descriptor (for plugins).
+ int
+ descriptor()
+ {
+ this->reopen_descriptor();
+ return this->descriptor_;
+ }
+
+ // Return the file last modification time. Calls gold_fatal if the stat
+ // system call failed.
+ Timespec
+ get_mtime();
+
private:
+ // Control for what views to clear.
+ enum Clear_views_mode
+ {
+ // Clear uncached views not used by an archive.
+ CLEAR_VIEWS_NORMAL,
+ // Clear all uncached views (including in an archive).
+ CLEAR_VIEWS_ARCHIVE,
+ // Clear all views (i.e., we're destroying the file).
+ CLEAR_VIEWS_ALL
+ };
+
// This class may not be copied.
File_read(const File_read&);
File_read& operator=(const File_read&);
- // Total bytes mapped into memory during the link. This variable
- // may not be accurate when running multi-threaded.
+ // Total bytes mapped into memory during the link if --stats.
static unsigned long long total_mapped_bytes;
- // Current number of bytes mapped into memory during the link. This
- // variable may not be accurate when running multi-threaded.
+ // Current number of bytes mapped into memory during the link if
+ // --stats.
static unsigned long long current_mapped_bytes;
- // High water mark of bytes mapped into memory during the link.
- // This variable may not be accurate when running multi-threaded.
+ // High water mark of bytes mapped into memory during the link if
+ // --stats.
static unsigned long long maximum_mapped_bytes;
// A view into the file.
class View
{
public:
+ // Specifies how to dispose the data on destruction of the view.
+ enum Data_ownership
+ {
+ // Data owned by File object - nothing done in destructor.
+ DATA_NOT_OWNED,
+ // Data allocated with new[] and owned by this object - should
+ // use delete[].
+ DATA_ALLOCATED_ARRAY,
+ // Data mmapped and owned by this object - should munmap.
+ DATA_MMAPPED
+ };
+
View(off_t start, section_size_type size, const unsigned char* data,
- bool cache, bool mapped)
+ unsigned int byteshift, bool cache, Data_ownership data_ownership)
: start_(start), size_(size), data_(data), lock_count_(0),
- cache_(cache), mapped_(mapped), accessed_(true)
+ byteshift_(byteshift), cache_(cache), data_ownership_(data_ownership),
+ accessed_(true)
{ }
~View();
bool
is_locked();
+ unsigned int
+ byteshift() const
+ { return this->byteshift_; }
+
void
set_cache()
{ this->cache_ = true; }
accessed() const
{ return this->accessed_; }
+ // Returns TRUE if this view contains permanent data -- e.g., data that
+ // was supplied by the owner of the File object.
+ bool
+ is_permanent_view() const
+ { return this->data_ownership_ == DATA_NOT_OWNED; }
+
private:
View(const View&);
View& operator=(const View&);
+ // The file offset of the start of the view.
off_t start_;
+ // The size of the view.
section_size_type size_;
+ // A pointer to the actual bytes.
const unsigned char* data_;
+ // The number of locks on this view.
int lock_count_;
+ // The number of bytes that the view is shifted relative to the
+ // underlying file. This is used to align data. This is normally
+ // zero, except possibly for an object in an archive.
+ unsigned int byteshift_;
+ // Whether the view is cached.
bool cache_;
- bool mapped_;
+ // Whether the view is mapped into memory. If not, data_ points
+ // to memory allocated using new[].
+ Data_ownership data_ownership_;
+ // Whether the view has been accessed recently.
bool accessed_;
};
friend class View;
friend class File_view;
+ // The type of a mapping from page start and byte shift to views.
+ typedef std::map<std::pair<off_t, unsigned int>, View*> Views;
+
+ // A simple list of Views.
+ typedef std::list<View*> Saved_views;
+
+ // Open the descriptor if necessary.
+ void
+ reopen_descriptor();
+
// Find a view into the file.
View*
- find_view(off_t start, section_size_type size) const;
+ find_view(off_t start, section_size_type size, unsigned int byteshift,
+ View** vshifted) const;
// Read data from the file into a buffer.
void
- do_read(off_t start, section_size_type size, void* p) const;
+ do_read(off_t start, section_size_type size, void* p);
+
+ // Add a view.
+ void
+ add_view(View*);
+
+ // Make a view into the file.
+ View*
+ make_view(off_t start, section_size_type size, unsigned int byteshift,
+ bool cache);
// Find or make a view into the file.
View*
- find_or_make_view(off_t start, section_size_type size, bool cache);
+ find_or_make_view(off_t offset, off_t start, section_size_type size,
+ bool aligned, bool cache);
// Clear the file views.
void
- clear_views(bool);
+ clear_views(Clear_views_mode);
// The size of a file page for buffering data.
static const off_t page_size = 8192;
pages(off_t file_size)
{ return (file_size + (page_size - 1)) & ~ (page_size - 1); }
- // The type of a mapping from page start to views.
- typedef std::map<off_t, View*> Views;
-
- // A simple list of Views.
- typedef std::list<View*> Saved_views;
-
// The maximum number of entries we will pass to ::readv.
static const size_t max_readv_entries = 128;
std::string name_;
// File descriptor.
int descriptor_;
+ // Whether we have regained the descriptor after releasing the file.
+ bool is_descriptor_opened_;
// The number of objects associated with this file. This will be
// more than 1 in the case of an archive.
int object_count_;
// List of views which were locked but had to be removed from views_
// because they were not large enough.
Saved_views saved_views_;
- // Specified file contents. Used only for testing purposes.
- const unsigned char* contents_;
// Total amount of space mapped into memory. This is only changed
// while the file is locked. When we unlock the file, we transfer
// the total to total_mapped_bytes, and reset this to zero.
size_t mapped_bytes_;
// Whether the file was released.
bool released_;
+ // A view containing the whole file. May be NULL if we mmap only
+ // the relevant parts of the file. Not NULL if:
+ // - Flag --mmap_whole_files is set (default on 64-bit hosts).
+ // - The contents was specified in the constructor. Used only for
+ // testing purposes).
+ View* whole_file_view_;
};
// A view of file data that persists even when the file is unlocked.
class Input_file
{
public:
+ enum Format
+ {
+ FORMAT_NONE,
+ FORMAT_ELF,
+ FORMAT_BINARY
+ };
+
Input_file(const Input_file_argument* input_argument)
: input_argument_(input_argument), found_name_(), file_(),
- is_in_sysroot_(false)
+ is_in_sysroot_(false), format_(FORMAT_NONE)
{ }
+ // Create an input file given just a filename.
+ Input_file(const char* name);
+
// Create an input file with the contents already provided. This is
// only used for testing. With this path, don't call the open
// method.
Input_file(const Task*, const char* name, const unsigned char* contents,
off_t size);
+ // Return the command line argument.
+ const Input_file_argument*
+ input_file_argument() const
+ { return this->input_argument_; }
+
+ // Return whether this is a file that we will search for in the list
+ // of directories.
+ bool
+ will_search_for() const;
+
// Open the file. If the open fails, this will report an error and
- // return false.
+ // return false. If there is a search, it starts at directory
+ // *PINDEX. *PINDEX should be initialized to zero. It may be
+ // restarted to find the next file with a matching name by
+ // incrementing the result and calling this again.
bool
- open(const General_options&, const Dirsearch&, const Task*);
+ open(const Dirsearch&, const Task*, int* pindex);
// Return the name given by the user. For -lc this will return "c".
const char*
is_in_sysroot() const
{ return this->is_in_sysroot_; }
+ // Whether this file is in a system directory.
+ bool
+ is_in_system_directory() const;
+
// Return whether this file is to be read only for its symbols.
bool
just_symbols() const;
+ // Return the format of the unconverted input file.
+ Format
+ format() const
+ { return this->format_; }
+
+ // Try to find a file in the extra search dirs. Returns true on success.
+ static bool
+ try_extra_search_path(int* pindex,
+ const Input_file_argument* input_argument,
+ std::string filename, std::string* found_name,
+ std::string* namep);
+
+ // Find the actual file.
+ static bool
+ find_file(const Dirsearch& dirpath, int* pindex,
+ const Input_file_argument* input_argument,
+ bool* is_in_sysroot,
+ std::string* found_name, std::string* namep);
+
private:
Input_file(const Input_file&);
Input_file& operator=(const Input_file&);
File_read file_;
// Whether we found the file in a directory in the system root.
bool is_in_sysroot_;
+ // Format of unconverted input file.
+ Format format_;
};
} // end namespace gold
projects / deliverable / binutils-gdb.git / blobdiff