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[patch/rfc] New (!) BFD target
- From: Andrew Cagney <ac131313 at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Wed, 22 Oct 2003 20:50:26 -0400
- Subject: [patch/rfc] New (!) BFD target
Hello,
The attached adds a really simple BFD "target" and is used:
bfd = bfd_open.. (...);
targ = target_bfd_reopen (bfd)
... operation involving targ ...
target_close (targ, 0);
Looking at solib-svr4, this object makes it possible to change this:
load_addr = read_pc () - tmp_bfd->start_address;
into this:
load_addr = (read_pc ()
- gdbarch_convert_from_func_ptr_addr (current_gdbarch,
bfd_get_start_address (tmp_bfd),
tmp_bfd_target));
i.e., pointer conversion is performed using the original executable and
not the running program. Something needed to fix PPC64 needs.
thoughts?
I'll look to commit this in a few days,
Andrew
2003-10-22 Andrew Cagney <cagney@redhat.com>
* target.h (struct target_ops): Add "to_data";
* bfd-target.h, bfd-target.c: New files.
* Makefile.in (SFILES): Add "bfd-target.c".
(COMMON_OBS): Add "bfd-target.o".
(bfd-target.o): Specify dependencies.
(bfd_target_h): Define.
* defs.h (XZALLOC): Define.
Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.460
diff -u -r1.460 Makefile.in
--- Makefile.in 23 Oct 2003 00:13:53 -0000 1.460
+++ Makefile.in 23 Oct 2003 00:35:10 -0000
@@ -511,7 +511,9 @@
SFILES = ada-exp.y ada-lang.c ada-typeprint.c ada-valprint.c ada-tasks.c \
ax-general.c ax-gdb.c \
- bcache.c block.c blockframe.c breakpoint.c buildsym.c \
+ bcache.c \
+ bfd-target.c \
+ block.c blockframe.c breakpoint.c buildsym.c \
c-exp.y c-lang.c c-typeprint.c c-valprint.c \
charset.c cli-out.c coffread.c coff-pe-read.c \
complaints.c completer.c corefile.c \
@@ -634,6 +636,7 @@
ax_gdb_h = ax-gdb.h
ax_h = ax.h $(doublest_h)
bcache_h = bcache.h
+bfd_target_h = bfd-target.h
block_h = block.h
breakpoint_h = breakpoint.h $(frame_h) $(value_h) $(gdb_events_h)
buildsym_h = buildsym.h
@@ -866,7 +869,9 @@
$(SUBDIR_CLI_SRCS)
TAGFILES_WITH_SRCDIR = $(HFILES_WITH_SRCDIR)
-COMMON_OBS = version.o blockframe.o breakpoint.o findvar.o regcache.o \
+COMMON_OBS = version.o \
+ bfd-target.o \
+ blockframe.o breakpoint.o findvar.o regcache.o \
charset.o disasm.o dummy-frame.o \
source.o values.o eval.o valops.o valarith.o valprint.o printcmd.o \
block.o symtab.o symfile.o symmisc.o linespec.o dictionary.o \
@@ -1599,6 +1604,8 @@
$(regcache_h)
ax-general.o: ax-general.c $(defs_h) $(ax_h) $(value_h) $(gdb_string_h)
bcache.o: bcache.c $(defs_h) $(gdb_obstack_h) $(bcache_h) $(gdb_string_h)
+bfd-target.o: bfd-target.c $(defs_h) $(target_h) $(bfd_target_h) \
+ $(gdb_assert_h) $(gdb_string_h)
block.o: block.c $(defs_h) $(block_h) $(symtab_h) $(symfile_h) \
$(gdb_obstack_h) $(cp_support_h)
blockframe.o: blockframe.c $(defs_h) $(symtab_h) $(bfd_h) $(symfile_h) \
Index: bfd-target.c
===================================================================
RCS file: bfd-target.c
diff -N bfd-target.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ bfd-target.c 23 Oct 2003 00:35:10 -0000
@@ -0,0 +1,120 @@
+/* Very simple "bfd" target, for GDB, the GNU debugger.
+
+ Copyright 2003 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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 2 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include "defs.h"
+#include "target.h"
+#include "bfd-target.h"
+#include "gdb_assert.h"
+#include "gdb_string.h"
+
+/* Locate all mappable sections of a BFD file, filling in a target
+ section for each. */
+
+struct section_closure
+{
+ struct section_table *end;
+};
+
+static void
+add_to_section_table (struct bfd *abfd, struct bfd_section *asect,
+ void *closure)
+{
+ struct section_closure *pp = closure;
+ flagword aflag;
+
+ /* NOTE: cagney/2003-10-22: Is this pruning useful? */
+ aflag = bfd_get_section_flags (abfd, asect);
+ if (!(aflag & SEC_ALLOC))
+ return;
+ if (bfd_section_size (abfd, asect) == 0)
+ return;
+ pp->end->bfd = abfd;
+ pp->end->the_bfd_section = asect;
+ pp->end->addr = bfd_section_vma (abfd, asect);
+ pp->end->endaddr = pp->end->addr + bfd_section_size (abfd, asect);
+ pp->end++;
+}
+
+void
+build_target_sections_from_bfd (struct target_ops *targ, struct bfd *abfd)
+{
+ unsigned count;
+ struct section_table *start;
+ struct section_closure cl;
+
+ count = bfd_count_sections (abfd);
+ target_resize_to_sections (targ, count);
+ start = targ->to_sections;
+ cl.end = targ->to_sections;
+ bfd_map_over_sections (abfd, add_to_section_table, &cl);
+ gdb_assert (cl.end - start <= count);
+}
+
+LONGEST
+target_bfd_read_partial (struct target_ops *ops,
+ enum target_object object,
+ const char *annex, void *buf,
+ ULONGEST offset, LONGEST len)
+{
+ switch (object)
+ {
+ case TARGET_OBJECT_MEMORY:
+ {
+ struct section_table *s = target_section_by_addr (ops, offset);
+ if (s == NULL)
+ return -1;
+ /* If the length extends beyond the section, truncate it. Be
+ careful to not suffer from overflow (wish S contained a
+ length). */
+ if ((offset - s->addr + len) > (s->endaddr - s->addr))
+ len = (s->endaddr - s->addr) - (offset - s->addr);
+ if (bfd_get_section_contents (s->bfd, s->the_bfd_section, buf,
+ offset - s->addr, len))
+ return len;
+ else
+ return -1;
+ }
+ default:
+ return -1;
+ }
+}
+
+void
+target_bfd_xclose (struct target_ops *t, int quitting)
+{
+ bfd_close (t->to_data);
+ xfree (t->to_sections);
+ xfree (t);
+}
+
+struct target_ops *
+target_bfd_reopen (struct bfd *bfd)
+{
+ struct target_ops *t = XZALLOC (struct target_ops);
+ t->to_shortname = "bfd";
+ t->to_longname = "BFD backed target";
+ t->to_doc = "You should never see this";
+ t->to_read_partial = target_bfd_read_partial;
+ t->to_xclose = target_bfd_xclose;
+ t->to_data = bfd;
+ build_target_sections_from_bfd (t, bfd);
+ return t;
+}
Index: bfd-target.h
===================================================================
RCS file: bfd-target.h
diff -N bfd-target.h
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ bfd-target.h 23 Oct 2003 00:35:10 -0000
@@ -0,0 +1,39 @@
+/* Very simple "bfd" target, for GDB, the GNU debugger.
+
+ Copyright 2003 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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 2 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., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#ifndef BFD_TARGET_H
+#define BFD_TARGET_H
+
+struct bfd;
+struct target_ops;
+
+/* Given an existing BFD, re-open it as a "struct target_ops". On
+ close, it will also close the corresponding BFD (which is like
+ freopen and fdopen). */
+struct target_ops *target_bfd_reopen (struct bfd *bfd);
+
+/* Map over ABFD's sections, creating corresponding entries in the
+ target's section table. */
+
+void build_target_sections_from_bfd (struct target_ops *targ,
+ struct bfd *abfd);
+
+#endif
Index: defs.h
===================================================================
RCS file: /cvs/src/src/gdb/defs.h,v
retrieving revision 1.132
diff -u -r1.132 defs.h
--- defs.h 20 Oct 2003 15:37:58 -0000 1.132
+++ defs.h 23 Oct 2003 00:35:10 -0000
@@ -871,6 +871,7 @@
/* Utility macros to allocate typed memory. Avoids errors like
``struct foo *foo = xmalloc (sizeof bar)'' and ``struct foo *foo =
(struct foo *) xmalloc (sizeof bar)''. */
+#define XZALLOC(TYPE) ((TYPE*) memset (xmalloc (sizeof (TYPE)), 0, sizeof (TYPE)))
#define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE)))
#define XCALLOC(NMEMB, TYPE) ((TYPE*) xcalloc ((NMEMB), sizeof (TYPE)))
Index: target.h
===================================================================
RCS file: /cvs/src/src/gdb/target.h,v
retrieving revision 1.47
diff -u -r1.47 target.h
--- target.h 23 Oct 2003 00:13:53 -0000 1.47
+++ target.h 23 Oct 2003 00:35:10 -0000
@@ -268,6 +268,8 @@
char *to_doc; /* Documentation. Does not include trailing
newline, and starts with a one-line descrip-
tion (probably similar to to_longname). */
+ /* Per-target scratch pad. */
+ void *to_data;
/* The open routine takes the rest of the parameters from the
command, and (if successful) pushes a new target onto the
stack. Targets should supply this routine, if only to provide