1 /* Copyright (C) 1985, 1986, 1987, 1988, 1992, 1993, 1994, 2001, 2002, 2003,
2 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs 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 3 of the License, or
9 (at your option) any later version.
11 GNU Emacs 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 GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
21 * unexec.c - Convert a running program into an a.out file.
23 * Author: Spencer W. Thomas
24 * Computer Science Dept.
26 * Date: Tue Mar 2 1982
27 * Modified heavily since then.
30 * unexec (new_name, a_name, data_start, bss_start, entry_address)
31 * char *new_name, *a_name;
32 * unsigned data_start, bss_start, entry_address;
34 * Takes a snapshot of the program and makes an a.out format file in the
35 * file named by the string argument new_name.
36 * If a_name is non-NULL, the symbol table will be taken from the given file.
37 * On some machines, an existing a_name file is required.
39 * The boundaries within the a.out file may be adjusted with the data_start
40 * and bss_start arguments. Either or both may be given as 0 for defaults.
42 * Data_start gives the boundary between the text segment and the data
43 * segment of the program. The text segment can contain shared, read-only
44 * program code and literal data, while the data segment is always unshared
45 * and unprotected. Data_start gives the lowest unprotected address.
46 * The value you specify may be rounded down to a suitable boundary
47 * as required by the machine you are using.
49 * Specifying zero for data_start means the boundary between text and data
50 * should not be the same as when the program was loaded.
51 * If NO_REMAP is defined, the argument data_start is ignored and the
52 * segment boundaries are never changed.
54 * Bss_start indicates how much of the data segment is to be saved in the
55 * a.out file and restored when the program is executed. It gives the lowest
56 * unsaved address, and is rounded up to a page boundary. The default when 0
57 * is given assumes that the entire data segment is to be stored, including
58 * the previous data and bss as well as any additional storage allocated with
61 * The new file is set up to start at entry_address.
63 * If you make improvements I'd like to get them too.
64 * harpo!utah-cs!thomas, thomas@Utah-20
68 /* Modified to support SysVr3 shared libraries by James Van Artsdalen
69 * of Dell Computer Corporation. james@bigtex.cactus.org.
72 /* There are several compilation parameters affecting unexec:
76 Define this if your system uses COFF for executables.
80 Define this if you do not want to try to save Emacs's pure data areas
81 as part of the text segment.
83 Saving them as text is good because it allows users to share more.
85 However, on machines that locate the text area far from the data area,
86 the boundary cannot feasibly be moved. Such machines require
89 Also, remapping can cause trouble with the built-in startup routine
90 /lib/crt0.o, which defines `environ' as an initialized variable.
91 Dumping `environ' as pure does not work! So, to use remapping,
92 you must write a startup routine for your machine in Emacs's crt0.c.
93 If NO_REMAP is defined, Emacs uses the system's crt0.o.
97 Some machines that use COFF executables require that each section
98 start on a certain boundary *in the COFF file*. Such machines should
99 define SECTION_ALIGNMENT to a mask of the low-order bits that must be
100 zero on such a boundary. This mask is used to control padding between
101 segments in the COFF file.
103 If SECTION_ALIGNMENT is not defined, the segments are written
104 consecutively with no attempt at alignment. This is right for
109 Some machines require that the beginnings and ends of segments
110 *in core* be on certain boundaries. For most machines, a page
111 boundary is sufficient. That is the default. When a larger
112 boundary is needed, define SEGMENT_MASK to a mask of
113 the bits that must be zero on such a boundary.
117 Some machines count the a.out header as part of the size of the text
118 segment (a_text); they may actually load the header into core as the
119 first data in the text segment. Some have additional padding between
120 the header and the real text of the program that is counted in a_text.
122 For these machines, define A_TEXT_OFFSET(HDR) to examine the header
123 structure HDR and return the number of bytes to add to `a_text'
124 before writing it (above and beyond the number of bytes of actual
125 program text). HDR's standard fields are already correct, except that
126 this adjustment to the `a_text' field has not yet been made;
127 thus, the amount of offset can depend on the data in the file.
131 If defined, this macro specifies the number of bytes to seek into the
132 a.out file before starting to write the text segment.
136 This macro can be used to generate statements to adjust or
137 initialize nonstandard fields in the file header
141 Macro to correct an int which is the bit pattern of a pointer to a byte
142 into an int which is the number of a byte.
144 This macro has a default definition which is usually right.
145 This default definition is a no-op on most machines (where a
146 pointer looks like an int) but not on all machines.
151 #define PERROR(arg) perror (arg); return -1
154 #define PERROR(file) report_error (file, new)
157 #ifndef CANNOT_DUMP /* all rest of file! */
159 #if defined(COFF) && defined(HAVE_COFF_H)
163 #include <fcntl.h> /* for O_RDONLY, O_RDWR */
164 #include <crt0.h> /* for _crt0_startup_flags and its bits */
165 static int save_djgpp_startup_flags
;
166 #endif /* __DJGPP__ > 1 */
167 #define filehdr external_filehdr
168 #define scnhdr external_scnhdr
169 #define syment external_syment
170 #define auxent external_auxent
171 #define n_numaux e_numaux
172 #define n_type e_type
175 unsigned short magic
; /* type of file */
176 unsigned short vstamp
; /* version stamp */
177 unsigned long tsize
; /* text size in bytes, padded to FW bdry*/
178 unsigned long dsize
; /* initialized data " " */
179 unsigned long bsize
; /* uninitialized data " " */
180 unsigned long entry
; /* entry pt. */
181 unsigned long text_start
;/* base of text used for this file */
182 unsigned long data_start
;/* base of data used for this file */
184 #endif /* not MSDOS */
187 #endif /* not COFF */
189 /* Define getpagesize if the system does not.
190 Note that this may depend on symbols defined in a.out.h. */
191 #include "getpagesize.h"
193 #ifndef makedev /* Try to detect types.h already loaded */
194 #include <sys/types.h>
197 #include <sys/stat.h>
200 #include <sys/file.h> /* Must be after sys/types.h for USG*/
214 extern char *start_of_text (); /* Start of text */
215 extern char *start_of_data (); /* Start of initialized data */
218 static long block_copy_start
; /* Old executable start point */
219 static struct filehdr f_hdr
; /* File header */
220 static struct aouthdr f_ohdr
; /* Optional file header (a.out) */
221 long bias
; /* Bias to add for growth */
222 long lnnoptr
; /* Pointer to line-number info within file */
223 #define SYMS_START block_copy_start
225 static long text_scnptr
;
226 static long data_scnptr
;
228 static long coff_offset
;
233 extern void *sbrk ();
236 /* Some systems with __STDC__ compilers still declare this `char *' in some
237 header file, and our declaration conflicts. The return value is always
238 cast, so it should be harmless to leave it undefined. Hopefully
239 machines with different size pointers and ints declare sbrk in a header
242 extern void *sbrk ();
244 extern char *sbrk ();
245 #endif /* __STDC__ */
249 #define SYMS_START ((long) N_SYMOFF (ohdr))
253 #define MY_ID HP9000S200_ID
257 #endif /* no HP9000S200_ID */
258 static MAGIC OLDMAGIC
= {MY_ID
, SHARE_MAGIC
};
259 static MAGIC NEWMAGIC
= {MY_ID
, DEMAND_MAGIC
};
260 #define N_TXTOFF(x) TEXT_OFFSET(x)
261 #define N_SYMOFF(x) LESYM_OFFSET(x)
262 static struct exec hdr
, ohdr
;
266 #if defined (USG) && !defined (IRIS) && !defined (GNU_LINUX)
267 static struct bhdr hdr
, ohdr
;
268 #define a_magic fmagic
273 #define a_trsize rtsize
274 #define a_drsize rdsize
275 #define a_entry entry
276 #define N_BADMAG(x) \
277 (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
278 ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
279 #define NEWMAGIC FMAGIC
280 #else /* IRIS or not USG */
281 static struct exec hdr
, ohdr
;
282 #define NEWMAGIC ZMAGIC
283 #endif /* IRIS or not USG */
284 #endif /* not HPUX */
286 static int unexec_text_start
;
287 static int unexec_data_start
;
289 #endif /* not COFF */
293 /* Correct an int which is the bit pattern of a pointer to a byte
294 into an int which is the number of a byte.
295 This is a no-op on ordinary machines, but not on all. */
297 #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
298 #define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
306 report_error (file
, fd
)
312 report_file_error ("Cannot unexec", Fcons (build_string (file
), Qnil
));
316 #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
317 #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
318 #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
321 report_error_1 (fd
, msg
, a1
, a2
)
330 fprintf (stderr
, msg
, a1
, a2
);
331 fprintf (stderr
, "\n");
335 static int make_hdr ();
336 static int copy_text_and_data ();
337 static int copy_sym ();
338 static void mark_x ();
340 /* ****************************************************************
343 * Make the header in the new a.out from the header in core.
344 * Modify the text and data sizes.
347 make_hdr (new, a_out
, data_start
, bss_start
, entry_address
, a_name
, new_name
)
349 unsigned data_start
, bss_start
, entry_address
;
355 auto struct scnhdr f_thdr
; /* Text section header */
356 auto struct scnhdr f_dhdr
; /* Data section header */
357 auto struct scnhdr f_bhdr
; /* Bss section header */
358 auto struct scnhdr scntemp
; /* Temporary section header */
361 #ifdef USG_SHARED_LIBRARIES
362 extern unsigned int bss_end
;
364 unsigned int bss_end
;
367 pagemask
= getpagesize () - 1;
369 /* Adjust text/data boundary. */
371 data_start
= (int) start_of_data ();
372 #else /* not NO_REMAP */
374 data_start
= (int) start_of_data ();
375 #endif /* not NO_REMAP */
376 data_start
= ADDR_CORRECT (data_start
);
379 data_start
= data_start
& ~SEGMENT_MASK
; /* (Down) to segment boundary. */
381 data_start
= data_start
& ~pagemask
; /* (Down) to page boundary. */
384 bss_end
= ADDR_CORRECT (sbrk (0)) + pagemask
;
385 bss_end
&= ~ pagemask
;
387 /* Adjust data/bss boundary. */
390 bss_start
= (ADDR_CORRECT (bss_start
) + pagemask
);
391 /* (Up) to page bdry. */
392 bss_start
&= ~ pagemask
;
393 if (bss_start
> bss_end
)
395 ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
402 if (data_start
> bss_start
) /* Can't have negative data size. */
404 ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
405 data_start
, bss_start
);
409 coff_offset
= 0L; /* stays zero, except in DJGPP */
411 /* Salvage as much info from the existing file as possible */
416 /* Support the coff-go32-exe format with a prepended stub, since
417 this is what GCC 2.8.0 and later generates by default in DJGPP. */
418 unsigned short mz_header
[3];
420 if (read (a_out
, &mz_header
, sizeof (mz_header
)) != sizeof (mz_header
))
424 if (mz_header
[0] == 0x5a4d || mz_header
[0] == 0x4d5a) /* "MZ" or "ZM" */
426 coff_offset
= (long)mz_header
[2] * 512L;
428 coff_offset
+= (long)mz_header
[1] - 512L;
429 lseek (a_out
, coff_offset
, 0);
432 lseek (a_out
, 0L, 0);
433 #endif /* __DJGPP__ > 1 */
435 if (read (a_out
, &f_hdr
, sizeof (f_hdr
)) != sizeof (f_hdr
))
439 block_copy_start
+= sizeof (f_hdr
);
440 if (f_hdr
.f_opthdr
> 0)
442 if (read (a_out
, &f_ohdr
, sizeof (f_ohdr
)) != sizeof (f_ohdr
))
446 block_copy_start
+= sizeof (f_ohdr
);
448 /* Loop through section headers, copying them in */
449 lseek (a_out
, coff_offset
+ sizeof (f_hdr
) + f_hdr
.f_opthdr
, 0);
450 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--) {
451 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
455 if (scntemp
.s_scnptr
> 0L)
457 if (block_copy_start
< scntemp
.s_scnptr
+ scntemp
.s_size
)
458 block_copy_start
= scntemp
.s_scnptr
+ scntemp
.s_size
;
460 if (strcmp (scntemp
.s_name
, ".text") == 0)
464 else if (strcmp (scntemp
.s_name
, ".data") == 0)
468 else if (strcmp (scntemp
.s_name
, ".bss") == 0)
476 ERROR0 ("can't build a COFF file from scratch yet");
479 /* Now we alter the contents of all the f_*hdr variables
480 to correspond to what we want to dump. */
482 #ifdef USG_SHARED_LIBRARIES
484 /* The amount of data we're adding to the file is distance from the
485 * end of the original .data space to the current end of the .data
489 bias
= bss_start
- (f_ohdr
.data_start
+ f_dhdr
.s_size
);
493 f_hdr
.f_flags
|= (F_RELFLG
| F_EXEC
);
495 f_ohdr
.text_start
= (long) start_of_text ();
496 f_ohdr
.tsize
= data_start
- f_ohdr
.text_start
;
497 f_ohdr
.data_start
= data_start
;
498 #endif /* NO_REMAP */
499 f_ohdr
.dsize
= bss_start
- f_ohdr
.data_start
;
500 f_ohdr
.bsize
= bss_end
- bss_start
;
501 /* On some machines, the old values are right.
502 ??? Maybe on all machines with NO_REMAP. */
503 f_thdr
.s_size
= f_ohdr
.tsize
;
504 f_thdr
.s_scnptr
= sizeof (f_hdr
) + sizeof (f_ohdr
);
505 f_thdr
.s_scnptr
+= (f_hdr
.f_nscns
) * (sizeof (f_thdr
));
506 lnnoptr
= f_thdr
.s_lnnoptr
;
507 #ifdef SECTION_ALIGNMENT
508 /* Some systems require special alignment
509 of the sections in the file itself. */
511 = (f_thdr
.s_scnptr
+ SECTION_ALIGNMENT
) & ~SECTION_ALIGNMENT
;
512 #endif /* SECTION_ALIGNMENT */
513 text_scnptr
= f_thdr
.s_scnptr
;
514 f_dhdr
.s_paddr
= f_ohdr
.data_start
;
515 f_dhdr
.s_vaddr
= f_ohdr
.data_start
;
516 f_dhdr
.s_size
= f_ohdr
.dsize
;
517 f_dhdr
.s_scnptr
= f_thdr
.s_scnptr
+ f_thdr
.s_size
;
518 #ifdef SECTION_ALIGNMENT
519 /* Some systems require special alignment
520 of the sections in the file itself. */
522 = (f_dhdr
.s_scnptr
+ SECTION_ALIGNMENT
) & ~SECTION_ALIGNMENT
;
523 #endif /* SECTION_ALIGNMENT */
524 #ifdef DATA_SECTION_ALIGNMENT
525 /* Some systems require special alignment
526 of the data section only. */
528 = (f_dhdr
.s_scnptr
+ DATA_SECTION_ALIGNMENT
) & ~DATA_SECTION_ALIGNMENT
;
529 #endif /* DATA_SECTION_ALIGNMENT */
530 data_scnptr
= f_dhdr
.s_scnptr
;
531 f_bhdr
.s_paddr
= f_ohdr
.data_start
+ f_ohdr
.dsize
;
532 f_bhdr
.s_vaddr
= f_ohdr
.data_start
+ f_ohdr
.dsize
;
533 f_bhdr
.s_size
= f_ohdr
.bsize
;
534 f_bhdr
.s_scnptr
= 0L;
535 #ifndef USG_SHARED_LIBRARIES
536 bias
= f_dhdr
.s_scnptr
+ f_dhdr
.s_size
- block_copy_start
;
539 if (f_hdr
.f_symptr
> 0L)
541 f_hdr
.f_symptr
+= bias
;
544 if (f_thdr
.s_lnnoptr
> 0L)
546 f_thdr
.s_lnnoptr
+= bias
;
549 #ifdef ADJUST_EXEC_HEADER
551 #endif /* ADJUST_EXEC_HEADER */
553 if (write (new, &f_hdr
, sizeof (f_hdr
)) != sizeof (f_hdr
))
558 if (write (new, &f_ohdr
, sizeof (f_ohdr
)) != sizeof (f_ohdr
))
563 #ifndef USG_SHARED_LIBRARIES
565 if (write (new, &f_thdr
, sizeof (f_thdr
)) != sizeof (f_thdr
))
570 if (write (new, &f_dhdr
, sizeof (f_dhdr
)) != sizeof (f_dhdr
))
575 if (write (new, &f_bhdr
, sizeof (f_bhdr
)) != sizeof (f_bhdr
))
580 #else /* USG_SHARED_LIBRARIES */
582 /* The purpose of this code is to write out the new file's section
585 * Scan through the original file's sections. If the encountered
586 * section is one we know (.text, .data or .bss), write out the
587 * correct header. If it is a section we do not know (such as
588 * .lib), adjust the address of where the section data is in the
589 * file, and write out the header.
591 * If any section precedes .text or .data in the file, this code
592 * will not adjust the file pointer for that section correctly.
595 /* This used to use sizeof (f_ohdr) instead of .f_opthdr.
596 .f_opthdr is said to be right when there is no optional header. */
597 lseek (a_out
, sizeof (f_hdr
) + f_hdr
.f_opthdr
, 0);
599 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--)
601 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
604 if (!strcmp (scntemp
.s_name
, f_thdr
.s_name
)) /* .text */
606 if (write (new, &f_thdr
, sizeof (f_thdr
)) != sizeof (f_thdr
))
609 else if (!strcmp (scntemp
.s_name
, f_dhdr
.s_name
)) /* .data */
611 if (write (new, &f_dhdr
, sizeof (f_dhdr
)) != sizeof (f_dhdr
))
614 else if (!strcmp (scntemp
.s_name
, f_bhdr
.s_name
)) /* .bss */
616 if (write (new, &f_bhdr
, sizeof (f_bhdr
)) != sizeof (f_bhdr
))
621 if (scntemp
.s_scnptr
)
622 scntemp
.s_scnptr
+= bias
;
623 if (write (new, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
627 #endif /* USG_SHARED_LIBRARIES */
631 #else /* if not COFF */
633 /* Get symbol table info from header of a.out file if given one. */
636 if (read (a_out
, &ohdr
, sizeof hdr
) != sizeof hdr
)
643 ERROR1 ("invalid magic number in %s", a_name
);
649 #ifdef MSDOS /* Demacs 1.1.1 91/10/16 HIRANO Satoshi */
650 bzero ((void *)&hdr
, sizeof hdr
);
652 bzero (&hdr
, sizeof hdr
);
656 unexec_text_start
= (long) start_of_text ();
657 unexec_data_start
= data_start
;
659 /* Machine-dependent fixup for header, or maybe for unexec_text_start */
660 #ifdef ADJUST_EXEC_HEADER
662 #endif /* ADJUST_EXEC_HEADER */
666 if (entry_address
!= 0)
667 hdr
.a_entry
= entry_address
;
669 hdr
.a_bss
= bss_end
- bss_start
;
670 hdr
.a_data
= bss_start
- data_start
;
672 hdr
.a_text
= ohdr
.a_text
;
673 #else /* not NO_REMAP */
674 hdr
.a_text
= data_start
- unexec_text_start
;
677 hdr
.a_text
+= A_TEXT_OFFSET (ohdr
);
680 #endif /* not NO_REMAP */
682 if (write (new, &hdr
, sizeof hdr
) != sizeof hdr
)
687 #if 0 /* This #ifndef caused a bug on GNU/Linux when using QMAGIC. */
688 /* This adjustment was done above only #ifndef NO_REMAP,
689 so only undo it now #ifndef NO_REMAP. */
690 /* #ifndef NO_REMAP */
693 hdr
.a_text
-= A_TEXT_OFFSET (ohdr
);
698 #endif /* not COFF */
701 write_segment (new, ptr
, end
)
703 register char *ptr
, *end
;
705 register int i
, nwrite
, ret
;
710 /* This is the normal amount to write at once.
711 It is the size of block that NFS uses. */
712 int writesize
= 1 << 13;
713 int pagesize
= getpagesize ();
716 bzero (zeros
, sizeof (zeros
));
718 for (i
= 0; ptr
< end
;)
720 /* Distance to next multiple of writesize. */
721 nwrite
= (((int) ptr
+ writesize
) & -writesize
) - (int) ptr
;
722 /* But not beyond specified end. */
723 if (nwrite
> end
- ptr
) nwrite
= end
- ptr
;
724 ret
= write (new, ptr
, nwrite
);
725 /* If write gets a page fault, it means we reached
726 a gap between the old text segment and the old data segment.
727 This gap has probably been remapped into part of the text segment.
728 So write zeros for it. */
735 /* Write only a page of zeros at once,
736 so that we we don't overshoot the start
737 of the valid memory in the old data segment. */
738 if (nwrite
> pagesize
)
740 write (new, zeros
, nwrite
);
742 #if 0 /* Now that we have can ask `write' to write more than a page,
743 it is legit for write do less than the whole amount specified. */
744 else if (nwrite
!= ret
)
747 "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
748 ptr
, new, nwrite
, ret
, errno
);
756 /* ****************************************************************
759 * Copy the text and data segments from memory to the new a.out
762 copy_text_and_data (new, a_out
)
770 #ifdef USG_SHARED_LIBRARIES
773 struct scnhdr scntemp
; /* Temporary section header */
775 /* The purpose of this code is to write out the new file's section
778 * Step through the section table. If we know the section (.text,
779 * .data) do the appropriate thing. Otherwise, if the section has
780 * no allocated space in the file (.bss), do nothing. Otherwise,
781 * the section has space allocated in the file, and is not a section
782 * we know. So just copy it.
785 lseek (a_out
, sizeof (struct filehdr
) + sizeof (struct aouthdr
), 0);
787 for (scns
= f_hdr
.f_nscns
; scns
> 0; scns
--)
789 if (read (a_out
, &scntemp
, sizeof (scntemp
)) != sizeof (scntemp
))
792 if (!strcmp (scntemp
.s_name
, ".text"))
794 lseek (new, (long) text_scnptr
, 0);
795 ptr
= (char *) f_ohdr
.text_start
;
796 end
= ptr
+ f_ohdr
.tsize
;
797 write_segment (new, ptr
, end
);
799 else if (!strcmp (scntemp
.s_name
, ".data"))
801 lseek (new, (long) data_scnptr
, 0);
802 ptr
= (char *) f_ohdr
.data_start
;
803 end
= ptr
+ f_ohdr
.dsize
;
804 write_segment (new, ptr
, end
);
806 else if (!scntemp
.s_scnptr
)
807 ; /* do nothing - no data for this section */
812 long old_a_out_ptr
= lseek (a_out
, 0, 1);
814 lseek (a_out
, scntemp
.s_scnptr
, 0);
815 for (size
= scntemp
.s_size
; size
> 0; size
-= sizeof (page
))
817 n
= size
> sizeof (page
) ? sizeof (page
) : size
;
818 if (read (a_out
, page
, n
) != n
|| write (new, page
, n
) != n
)
821 lseek (a_out
, old_a_out_ptr
, 0);
825 #else /* COFF, but not USG_SHARED_LIBRARIES */
829 /* Dump the original table of exception handlers, not the one
830 where our exception hooks are registered. */
831 __djgpp_exception_toggle ();
833 /* Switch off startup flags that might have been set at runtime
834 and which might change the way that dumped Emacs works. */
835 save_djgpp_startup_flags
= _crt0_startup_flags
;
836 _crt0_startup_flags
&= ~(_CRT0_FLAG_NO_LFN
| _CRT0_FLAG_NEARPTR
);
840 lseek (new, (long) text_scnptr
, 0);
841 ptr
= (char *) f_ohdr
.text_start
;
842 end
= ptr
+ f_ohdr
.tsize
;
843 write_segment (new, ptr
, end
);
845 lseek (new, (long) data_scnptr
, 0);
846 ptr
= (char *) f_ohdr
.data_start
;
847 end
= ptr
+ f_ohdr
.dsize
;
848 write_segment (new, ptr
, end
);
852 /* Restore our exception hooks. */
853 __djgpp_exception_toggle ();
855 /* Restore the startup flags. */
856 _crt0_startup_flags
= save_djgpp_startup_flags
;
860 #endif /* USG_SHARED_LIBRARIES */
862 #else /* if not COFF */
864 /* Some machines count the header as part of the text segment.
865 That is to say, the header appears in core
866 just before the address that start_of_text returns.
867 For them, N_TXTOFF is the place where the header goes.
868 We must adjust the seek to the place after the header.
869 Note that at this point hdr.a_text does *not* count
870 the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
873 lseek (new, (long) A_TEXT_SEEK (hdr
), 0);
875 lseek (new, (long) N_TXTOFF (hdr
), 0);
876 #endif /* no A_TEXT_SEEK */
878 ptr
= (char *) unexec_text_start
;
879 end
= ptr
+ hdr
.a_text
;
880 write_segment (new, ptr
, end
);
882 ptr
= (char *) unexec_data_start
;
883 end
= ptr
+ hdr
.a_data
;
884 /* This lseek is certainly incorrect when A_TEXT_OFFSET
885 and I believe it is a no-op otherwise.
886 Let's see if its absence ever fails. */
887 /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
888 write_segment (new, ptr
, end
);
890 #endif /* not COFF */
895 /* ****************************************************************
898 * Copy the relocation information and symbol table from the a.out to the new
901 copy_sym (new, a_out
, a_name
, new_name
)
903 char *a_name
, *new_name
;
912 if (SYMS_START
== 0L)
917 if (lnnoptr
) /* if there is line number info */
918 lseek (a_out
, coff_offset
+ lnnoptr
, 0); /* start copying from there */
920 lseek (a_out
, coff_offset
+ SYMS_START
, 0); /* Position a.out to symtab. */
922 lseek (a_out
, SYMS_START
, 0); /* Position a.out to symtab. */
923 #endif /* not COFF */
925 while ((n
= read (a_out
, page
, sizeof page
)) > 0)
927 if (write (new, page
, n
) != n
)
939 /* ****************************************************************
942 * After successfully building the new a.out, mark it executable
950 int new = 0; /* for PERROR */
954 if (stat (name
, &sbuf
) == -1)
958 sbuf
.st_mode
|= 0111 & ~um
;
959 if (chmod (name
, sbuf
.st_mode
) == -1)
964 #ifndef COFF_BSD_SYMBOLS
967 * If the COFF file contains a symbol table and a line number section,
968 * then any auxiliary entries that have values for x_lnnoptr must
969 * be adjusted by the amount that the line number section has moved
970 * in the file (bias computed in make_hdr). The #@$%&* designers of
971 * the auxiliary entry structures used the absolute file offsets for
972 * the line number entry rather than an offset from the start of the
973 * line number section!
975 * When I figure out how to scan through the symbol table and pick out
976 * the auxiliary entries that need adjustment, this routine will
977 * be fixed. As it is now, all such entries are wrong and sdb
978 * will complain. Fred Fish, UniSoft Systems Inc.
981 /* This function is probably very slow. Instead of reopening the new
982 file for input and output it should copy from the old to the new
983 using the two descriptors already open (WRITEDESC and READDESC).
984 Instead of reading one small structure at a time it should use
985 a reasonable size buffer. But I don't have time to work on such
986 things, so I am installing it as submitted to me. -- RMS. */
988 adjust_lnnoptrs (writedesc
, readdesc
, new_name
)
995 struct syment symentry
;
996 union auxent auxentry
;
998 if (!lnnoptr
|| !f_hdr
.f_symptr
)
1002 if ((new = writedesc
) < 0)
1004 if ((new = open (new_name
, O_RDWR
)) < 0)
1011 lseek (new, f_hdr
.f_symptr
, 0);
1012 for (nsyms
= 0; nsyms
< f_hdr
.f_nsyms
; nsyms
++)
1014 read (new, &symentry
, SYMESZ
);
1015 if (symentry
.n_numaux
)
1017 read (new, &auxentry
, AUXESZ
);
1019 if (ISFCN (symentry
.n_type
) || symentry
.n_type
== 0x2400)
1021 auxentry
.x_sym
.x_fcnary
.x_fcn
.x_lnnoptr
+= bias
;
1022 lseek (new, -AUXESZ
, 1);
1023 write (new, &auxentry
, AUXESZ
);
1033 #endif /* COFF_BSD_SYMBOLS */
1037 /* ****************************************************************
1042 unexec (new_name
, a_name
, data_start
, bss_start
, entry_address
)
1043 char *new_name
, *a_name
;
1044 unsigned data_start
, bss_start
, entry_address
;
1046 int new, a_out
= -1;
1048 if (a_name
&& (a_out
= open (a_name
, O_RDONLY
)) < 0)
1052 if ((new = creat (new_name
, 0666)) < 0)
1057 if (make_hdr (new, a_out
, data_start
, bss_start
, entry_address
, a_name
, new_name
) < 0
1058 || copy_text_and_data (new, a_out
) < 0
1059 || copy_sym (new, a_out
, a_name
, new_name
) < 0
1061 #ifndef COFF_BSD_SYMBOLS
1062 || adjust_lnnoptrs (new, a_out
, new_name
) < 0
1068 /* unlink (new_name); /* Failed, unlink new a.out */
1079 #endif /* not CANNOT_DUMP */
1081 /* arch-tag: 62409b69-e27a-4a7c-9413-0210d6b54e7f
1082 (do not change this comment) */