1da77581c0
Right now we always share per-BFD data across objfiles, if there is a BFD. This works fine. However, we're going to start sharing more data, and sometimes this data will come directly from sections of the BFD. If such a section has SEC_RELOC set, then the data coming from that section will not be truly sharable -- the section will be program-space-dependent, and re-read by gdb for each objfile. This patch disallows per-BFD sharing in this case. This is a bit "heavy" in that we could in theory examine each bit of shared data for suitability. However, that is more complicated, and SEC_RELOC is rare enough that I think we needn't bother. Note that the "no sharing" case is equivalent to "gdb works as it historically did". That is, the sharing is a new(-ish) optimization. Built and regtested on x86-64 Fedora 18. * gdb_bfd.c (struct gdb_bfd_data) <relocation_computed, needs_relocations>: New fields. (gdb_bfd_requires_relocations): New function. * gdb_bfd.h (gdb_bfd_requires_relocations): Declare. * objfiles.c (get_objfile_bfd_data): Disallow sharing if the BFD needs relocations applied.
144 lines
5.1 KiB
C
144 lines
5.1 KiB
C
/* Definitions for BFD wrappers used by GDB.
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Copyright (C) 2011-2013 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef GDB_BFD_H
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#define GDB_BFD_H
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#include "registry.h"
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DECLARE_REGISTRY (bfd);
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/* Make a copy ABFD's filename using bfd_alloc, and reassign it to the
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BFD. This ensures that the BFD's filename has the same lifetime as
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the BFD itself. */
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void gdb_bfd_stash_filename (struct bfd *abfd);
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/* Open a read-only (FOPEN_RB) BFD given arguments like bfd_fopen.
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Returns NULL on error. On success, returns a new reference to the
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BFD, which must be freed with gdb_bfd_unref. BFDs returned by this
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call are shared among all callers opening the same file. If FD is
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not -1, then after this call it is owned by BFD. */
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struct bfd *gdb_bfd_open (const char *name, const char *target, int fd);
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/* Increment the reference count of ABFD. It is fine for ABFD to be
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NULL; in this case the function does nothing. */
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void gdb_bfd_ref (struct bfd *abfd);
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/* Decrement the reference count of ABFD. If this is the last
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reference, ABFD will be freed. If ABFD is NULL, this function does
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nothing. */
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void gdb_bfd_unref (struct bfd *abfd);
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/* Mark the CHILD BFD as being a member of PARENT. Also, increment
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the reference count of CHILD. Calling this function ensures that
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as along as CHILD remains alive, PARENT will as well. Both CHILD
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and PARENT must be non-NULL. This can be called more than once
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with the same arguments; but it is not allowed to call it for a
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single CHILD with different values for PARENT. */
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void gdb_bfd_mark_parent (bfd *child, bfd *parent);
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/* Try to read or map the contents of the section SECT. If
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successful, the section data is returned and *SIZE is set to the
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size of the section data; this may not be the same as the size
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according to bfd_get_section_size if the section was compressed.
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The returned section data is associated with the BFD and will be
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destroyed when the BFD is destroyed. There is no other way to free
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it; for temporary uses of section data, see
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bfd_malloc_and_get_section. SECT may not have relocations. This
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function will throw on error. */
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const gdb_byte *gdb_bfd_map_section (asection *section, bfd_size_type *size);
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/* Compute the CRC for ABFD. The CRC is used to find and verify
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separate debug files. When successful, this fills in *CRC_OUT and
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returns 1. Otherwise, this issues a warning and returns 0. */
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int gdb_bfd_crc (struct bfd *abfd, unsigned long *crc_out);
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/* A wrapper for bfd_fopen that initializes the gdb-specific reference
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count and calls gdb_bfd_stash_filename. */
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bfd *gdb_bfd_fopen (const char *, const char *, const char *, int);
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/* A wrapper for bfd_openr that initializes the gdb-specific reference
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count and calls gdb_bfd_stash_filename. */
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bfd *gdb_bfd_openr (const char *, const char *);
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/* A wrapper for bfd_openw that initializes the gdb-specific reference
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count and calls gdb_bfd_stash_filename. */
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bfd *gdb_bfd_openw (const char *, const char *);
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/* A wrapper for bfd_openr_iovec that initializes the gdb-specific
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reference count and calls gdb_bfd_stash_filename. */
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bfd *gdb_bfd_openr_iovec (const char *filename, const char *target,
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void *(*open_func) (struct bfd *nbfd,
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void *open_closure),
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void *open_closure,
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file_ptr (*pread_func) (struct bfd *nbfd,
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void *stream,
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void *buf,
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file_ptr nbytes,
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file_ptr offset),
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int (*close_func) (struct bfd *nbfd,
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void *stream),
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int (*stat_func) (struct bfd *abfd,
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void *stream,
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struct stat *sb));
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/* A wrapper for bfd_openr_next_archived_file that initializes the
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gdb-specific reference count and calls gdb_bfd_stash_filename. */
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bfd *gdb_bfd_openr_next_archived_file (bfd *archive, bfd *previous);
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/* A wrapper for bfd_fdopenr that initializes the gdb-specific
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reference count and calls gdb_bfd_stash_filename. */
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bfd *gdb_bfd_fdopenr (const char *filename, const char *target, int fd);
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/* Return the index of the BFD section SECTION. Ordinarily this is
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just the section's index, but for some special sections, like
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bfd_com_section_ptr, it will be a synthesized value. */
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int gdb_bfd_section_index (bfd *abfd, asection *section);
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/* Like bfd_count_sections, but include any possible global sections,
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like bfd_com_section_ptr. */
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int gdb_bfd_count_sections (bfd *abfd);
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/* Return true if any section requires relocations, false
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otherwise. */
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int gdb_bfd_requires_relocations (bfd *abfd);
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#endif /* GDB_BFD_H */
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