xref: /openbsd/gnu/usr.bin/binutils/gdb/bfd-target.c (revision d415bd75)
1 /* Very simple "bfd" target, for GDB, the GNU debugger.
2 
3    Copyright 2003 Free Software Foundation, Inc.
4 
5    This file is part of GDB.
6 
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 2 of the License, or
10    (at your option) any later version.
11 
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16 
17    You should have received a copy of the GNU General Public License
18    along with this program; if not, write to the Free Software
19    Foundation, Inc., 59 Temple Place - Suite 330,
20    Boston, MA 02111-1307, USA.  */
21 
22 #include "defs.h"
23 #include "target.h"
24 #include "bfd-target.h"
25 #include "gdb_assert.h"
26 #include "gdb_string.h"
27 
28 /* Locate all mappable sections of a BFD file, filling in a target
29    section for each.  */
30 
31 struct section_closure
32 {
33   struct section_table *end;
34 };
35 
36 static void
37 add_to_section_table (struct bfd *abfd, struct bfd_section *asect,
38 		      void *closure)
39 {
40   struct section_closure *pp = closure;
41   flagword aflag;
42 
43   /* NOTE: cagney/2003-10-22: Is this pruning useful?  */
44   aflag = bfd_get_section_flags (abfd, asect);
45   if (!(aflag & SEC_ALLOC))
46     return;
47   if (bfd_section_size (abfd, asect) == 0)
48     return;
49   pp->end->bfd = abfd;
50   pp->end->the_bfd_section = asect;
51   pp->end->addr = bfd_section_vma (abfd, asect);
52   pp->end->endaddr = pp->end->addr + bfd_section_size (abfd, asect);
53   pp->end++;
54 }
55 
56 void
57 build_target_sections_from_bfd (struct target_ops *targ, struct bfd *abfd)
58 {
59   unsigned count;
60   struct section_table *start;
61   struct section_closure cl;
62 
63   count = bfd_count_sections (abfd);
64   target_resize_to_sections (targ, count);
65   start = targ->to_sections;
66   cl.end = targ->to_sections;
67   bfd_map_over_sections (abfd, add_to_section_table, &cl);
68   gdb_assert (cl.end - start <= count);
69 }
70 
71 LONGEST
72 target_bfd_xfer_partial (struct target_ops *ops,
73 			 enum target_object object,
74 			 const char *annex, void *readbuf,
75 			 const void *writebuf, ULONGEST offset, LONGEST len)
76 {
77   switch (object)
78     {
79     case TARGET_OBJECT_MEMORY:
80       {
81 	struct section_table *s = target_section_by_addr (ops, offset);
82 	if (s == NULL)
83 	  return -1;
84 	/* If the length extends beyond the section, truncate it.  Be
85            careful to not suffer from overflow (wish S contained a
86            length).  */
87 	if ((offset - s->addr + len) > (s->endaddr - s->addr))
88 	  len = (s->endaddr - s->addr) - (offset - s->addr);
89 	if (readbuf != NULL
90 	    && !bfd_get_section_contents (s->bfd, s->the_bfd_section,
91 					  readbuf, offset - s->addr, len))
92 	  return -1;
93 #if 1
94 	if (writebuf != NULL)
95 	  return -1;
96 #else
97 	/* FIXME: cagney/2003-10-31: The BFD interface doesn't yet
98            take a const buffer.  */
99 	if (writebuf != NULL
100 	    && !bfd_set_section_contents (s->bfd, s->the_bfd_section,
101 					  writebuf, offset - s->addr, len))
102 	  return -1;
103 #endif
104 	return len;
105       }
106     default:
107       return -1;
108     }
109 }
110 
111 void
112 target_bfd_xclose (struct target_ops *t, int quitting)
113 {
114   bfd_close (t->to_data);
115   xfree (t->to_sections);
116   xfree (t);
117 }
118 
119 struct target_ops *
120 target_bfd_reopen (struct bfd *bfd)
121 {
122   struct target_ops *t = XZALLOC (struct target_ops);
123   t->to_shortname = "bfd";
124   t->to_longname = "BFD backed target";
125   t->to_doc = "You should never see this";
126   t->to_xfer_partial = target_bfd_xfer_partial;
127   t->to_xclose = target_bfd_xclose;
128   t->to_data = bfd;
129   build_target_sections_from_bfd (t, bfd);
130   return t;
131 }
132