1 /* Work with executable files, for GDB.
2 Copyright (C) 1988, 1989 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
29 #include <sys/types.h>
32 #include <sys/param.h>
41 extern char *getenv();
42 extern void child_create_inferior (), child_attach ();
43 extern void symbol_file_command ();
45 /* The Binary File Descriptor handle for the executable file. */
49 /* Whether to open exec and core files read-only or read-write. */
55 extern struct target_ops exec_ops;
66 if (exec_ops.sections) {
67 free (exec_ops.sections);
68 exec_ops.sections = NULL;
69 exec_ops.sections_end = NULL;
74 exec_file_command (filename, from_tty)
78 target_preopen (from_tty);
80 /* Remove any previous exec file. */
81 unpush_target (&exec_ops);
83 /* Now open and digest the file the user requested, if any. */
87 char *scratch_pathname;
90 filename = tilde_expand (filename);
91 make_cleanup (free, filename);
93 scratch_chan = openp (getenv ("PATH"), 1, filename,
94 write_files? O_RDWR: O_RDONLY, 0,
97 perror_with_name (filename);
99 exec_bfd = bfd_fdopenr (scratch_pathname, NULL, scratch_chan);
101 error ("Could not open `%s' as an executable file: %s",
102 scratch_pathname, bfd_errmsg (bfd_error));
103 if (!bfd_check_format (exec_bfd, bfd_object))
104 error ("\"%s\": not in executable format: %s.",
105 scratch_pathname, bfd_errmsg (bfd_error));
108 /* This code needs to be incorporated into BFD */
109 #ifdef COFF_ENCAPSULATE
110 /* If we have a coff header, it can give us better values for
111 text_start and exec_data_start. This is particularly useful
112 for remote debugging of embedded systems. */
113 if (N_FLAGS(exec_aouthdr) & N_FLAGS_COFF_ENCAPSULATE)
115 struct coffheader ch;
117 val = lseek (execchan, -(sizeof (AOUTHDR) + sizeof (ch)), 1);
119 perror_with_name (filename);
120 val = myread (execchan, &ch, sizeof (ch));
122 perror_with_name (filename);
123 text_start = ch.text_start;
124 exec_data_start = ch.data_start;
129 IS_OBJECT_FILE (exec_aouthdr) ? 0 : N_TXTADDR (exec_aouthdr);
130 exec_data_start = IS_OBJECT_FILE (exec_aouthdr)
131 ? exec_aouthdr.a_text : N_DATADDR (exec_aouthdr);
135 if (build_section_table (exec_bfd, &exec_ops.sections,
136 &exec_ops.sections_end))
137 error ("Can't find the file sections in `%s': %s",
138 exec_bfd->filename, bfd_errmsg (bfd_error));
142 push_target (&exec_ops);
144 /* Tell display code (if any) about the changed file name. */
145 if (exec_file_display_hook)
146 (*exec_file_display_hook) (filename);
149 printf ("No exec file now.\n");
152 /* Set both the exec file and the symbol file, in one command.
153 What a novelty. Why did GDB go through four major releases before this
154 command was added? */
157 file_command (arg, from_tty)
161 /* FIXME, if we lose on reading the symbol file, we should revert
162 the exec file, but that's rough. */
163 exec_file_command (arg, from_tty);
164 symbol_file_command (arg, from_tty);
168 /* Locate all mappable sections of a BFD file.
169 table_pp_char is a char * to get it through bfd_map_over_sections;
170 we cast it back to its proper type. */
173 add_to_section_table (abfd, asect, table_pp_char)
178 struct section_table **table_pp = (struct section_table **)table_pp_char;
181 aflag = bfd_get_section_flags (abfd, asect);
182 /* FIXME, we need to handle BSS segment here...it alloc's but doesn't load */
183 if (!(aflag & SEC_LOAD))
185 (*table_pp)->bfd = abfd;
186 (*table_pp)->sec_ptr = asect;
187 (*table_pp)->addr = bfd_section_vma (abfd, asect);
188 (*table_pp)->endaddr = (*table_pp)->addr + bfd_section_size (abfd, asect);
193 build_section_table (some_bfd, start, end)
195 struct section_table **start, **end;
199 count = bfd_count_sections (some_bfd);
201 abort(); /* return 1? */
204 *start = (struct section_table *) xmalloc (count * sizeof (**start));
206 bfd_map_over_sections (some_bfd, add_to_section_table, (char *)end);
207 if (*end > *start + count)
209 /* We could realloc the table, but it probably loses for most files. */
213 /* Read or write the exec file.
215 Args are address within a BFD file, address within gdb address-space,
216 length, and a flag indicating whether to read or write.
220 0: We cannot handle this address and length.
221 > 0: We have handled N bytes starting at this address.
222 (If N == length, we did it all.) We might be able
223 to handle more bytes beyond this length, but no
225 < 0: We cannot handle this address, but if somebody
226 else handles (-N) bytes, we can start from there.
228 The same routine is used to handle both core and exec files;
229 we just tail-call it with more arguments to select between them. */
232 xfer_memory (memaddr, myaddr, len, write, target)
237 struct target_ops *target;
240 struct section_table *p;
241 CORE_ADDR nextsectaddr, memend;
242 boolean (*xfer_fn) ();
247 memend = memaddr + len;
248 xfer_fn = write? bfd_set_section_contents: bfd_get_section_contents;
249 nextsectaddr = memend;
251 for (p = target->sections; p < target->sections_end; p++)
253 if (p->addr <= memaddr)
254 if (p->endaddr >= memend)
256 /* Entire transfer is within this section. */
257 res = xfer_fn (p->bfd, p->sec_ptr, myaddr, memaddr - p->addr, len);
258 return (res != false)? len: 0;
260 else if (p->endaddr <= memaddr)
262 /* This section ends before the transfer starts. */
267 /* This section overlaps the transfer. Just do half. */
268 len = p->endaddr - memaddr;
269 res = xfer_fn (p->bfd, p->sec_ptr, myaddr, memaddr - p->addr, len);
270 return (res != false)? len: 0;
272 else if (p->addr < nextsectaddr)
273 nextsectaddr = p->addr;
276 if (nextsectaddr >= memend)
277 return 0; /* We can't help */
279 return - (nextsectaddr - memaddr); /* Next boundary where we can help */
283 #ifdef REG_STACK_SEGMENT
285 /* Pyramids and AM29000s have an extra segment in the virtual address space
286 for the (control) stack of register-window frames. The AM29000 folk
287 call it the "register stack" rather than the "memory stack". */
288 else if (memaddr >= reg_stack_start && memaddr < reg_stack_end)
290 i = min (len, reg_stack_end - memaddr);
291 fileptr = memaddr - reg_stack_start + reg_stack_offset;
292 wanna_xfer = coredata;
294 #endif /* REG_STACK_SEGMENT */
300 struct section_table *p;
302 printf ("\tExecutable file `%s'.\n", bfd_get_filename(exec_bfd));
304 for (p = exec_ops.sections; p < exec_ops.sections_end; p++)
305 printf("\texecutable from 0x%08x to 0x%08x is %s\n",
307 bfd_section_name (exec_bfd, p->sec_ptr));
311 set_section_command (args, from_tty)
315 struct section_table *p;
318 unsigned long secaddr;
323 error ("Must specify section name and its virtual address");
325 /* Parse out section name */
326 for (secname = args; !isspace(*args); args++) ;
327 seclen = args - secname;
329 /* Parse out new virtual address */
330 secaddr = parse_and_eval_address (args);
332 for (p = exec_ops.sections; p < exec_ops.sections_end; p++) {
333 if (!strncmp (secname, bfd_section_name (exec_bfd, p->sec_ptr), seclen)
334 && bfd_section_name (exec_bfd, p->sec_ptr)[seclen] == '\0') {
335 offset = secaddr - p->addr;
337 p->endaddr += offset;
342 if (seclen >= sizeof (secprint))
343 seclen = sizeof (secprint) - 1;
344 strncpy (secprint, secname, seclen);
345 secprint[seclen] = '\0';
346 error ("Section %s not found", secprint);
349 struct target_ops exec_ops = {
350 "exec", "Local exec file",
351 "Use an executable file as a target.\n\
352 Specify the filename of the executable file.",
353 exec_file_command, exec_close, /* open, close */
354 child_attach, 0, 0, 0, /* attach, detach, resume, wait, */
355 0, 0, /* fetch_registers, store_registers, */
356 0, 0, 0, /* prepare_to_store, conv_to, conv_from, */
357 xfer_memory, exec_files_info,
358 0, 0, /* insert_breakpoint, remove_breakpoint, */
359 0, 0, 0, 0, 0, /* terminal stuff */
360 0, 0, /* kill, load */
361 0, 0, /* call fn, lookup sym */
362 child_create_inferior,
363 0, /* mourn_inferior */
364 file_stratum, 0, /* next */
365 0, 1, 0, 0, 0, /* all mem, mem, stack, regs, exec */
366 0, 0, /* section pointers */
367 OPS_MAGIC, /* Always the last thing */
374 add_com ("file", class_files, file_command,
375 "Use FILE as program to be debugged.\n\
376 It is read for its symbols, for getting the contents of pure memory,\n\
377 and it is the program executed when you use the `run' command.\n\
378 If FILE cannot be found as specified, your execution directory path\n\
379 ($PATH) is searched for a command of that name.\n\
380 No arg means to have no executable file and no symbols.");
382 add_com ("exec-file", class_files, exec_file_command,
383 "Use FILE as program for getting contents of pure memory.\n\
384 If FILE cannot be found as specified, your execution directory path\n\
385 is searched for a command of that name.\n\
386 No arg means have no executable file.");
388 add_com ("section", class_files, set_section_command,
389 "Change the base address of section SECTION of the exec file to ADDR.\n\
390 This can be used if the exec file does not contain section addresses,\n\
391 (such as in the a.out format), or when the addresses specified in the\n\
392 file itself are wrong. Each section must be changed separately. The\n\
393 ``info files'' command lists all the sections and their addresses.");
396 (add_set_cmd ("write", class_support, var_boolean, (char *)&write_files,
397 "Set writing into executable and core files.",
401 add_target (&exec_ops);