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authorBryan Newbold <bnewbold@robocracy.org>2017-02-20 00:05:23 -0800
committerBryan Newbold <bnewbold@robocracy.org>2017-02-20 00:05:23 -0800
commit5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8 (patch)
tree9b744b9dbf39e716e56daa620e2f3041968caf19 /unexec.c
downloadscm-5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8.tar.gz
scm-5ca6e8e6a4e5c022a6fb5d28f30219c22c99eda8.zip
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+/* Copyright (C) 1985,86,87,88,92,93,94 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs 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, or (at your option)
+any later version.
+
+GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA. */
+
+
+/*
+ * unexec.c - Convert a running program into an a.out file.
+ *
+ * Author: Spencer W. Thomas
+ * Computer Science Dept.
+ * University of Utah
+ * Date: Tue Mar 2 1982
+ * Modified heavily since then.
+ *
+ * Synopsis:
+ * unexec (new_name, a_name, data_start, bss_start, entry_address)
+ * char *new_name, *a_name;
+ * unsigned data_start, bss_start, entry_address;
+ *
+ * Takes a snapshot of the program and makes an a.out format file in the
+ * file named by the string argument new_name.
+ * If a_name is non-NULL, the symbol table will be taken from the given file.
+ * On some machines, an existing a_name file is required.
+ *
+ * The boundaries within the a.out file may be adjusted with the data_start
+ * and bss_start arguments. Either or both may be given as 0 for defaults.
+ *
+ * Data_start gives the boundary between the text segment and the data
+ * segment of the program. The text segment can contain shared, read-only
+ * program code and literal data, while the data segment is always unshared
+ * and unprotected. Data_start gives the lowest unprotected address.
+ * The value you specify may be rounded down to a suitable boundary
+ * as required by the machine you are using.
+ *
+ * Specifying zero for data_start means the boundary between text and data
+ * should not be the same as when the program was loaded.
+ * If NO_REMAP is defined, the argument data_start is ignored and the
+ * segment boundaries are never changed.
+ *
+ * Bss_start indicates how much of the data segment is to be saved in the
+ * a.out file and restored when the program is executed. It gives the lowest
+ * unsaved address, and is rounded up to a page boundary. The default when 0
+ * is given assumes that the entire data segment is to be stored, including
+ * the previous data and bss as well as any additional storage allocated with
+ * break (2).
+ *
+ * The new file is set up to start at entry_address.
+ *
+ * If you make improvements I'd like to get them too.
+ * harpo!utah-cs!thomas, thomas@Utah-20
+ *
+ */
+
+/* Modified to support SysVr3 shared libraries by James Van Artsdalen
+ * of Dell Computer Corporation. james@bigtex.cactus.org.
+ */
+
+/* There are several compilation parameters affecting unexec:
+
+* COFF
+
+Define this if your system uses COFF for executables.
+
+* COFF_ENCAPSULATE
+
+Define this if you are using the GNU coff encapsulated a.out format.
+This is closer to a.out than COFF. You should *not* define COFF if
+you define COFF_ENCAPSULATE
+
+Otherwise we assume you use Berkeley format.
+
+* NO_REMAP
+
+Define this if you do not want to try to save Emacs's pure data areas
+as part of the text segment.
+
+Saving them as text is good because it allows users to share more.
+
+However, on machines that locate the text area far from the data area,
+the boundary cannot feasibly be moved. Such machines require
+NO_REMAP.
+
+Also, remapping can cause trouble with the built-in startup routine
+/lib/crt0.o, which defines `environ' as an initialized variable.
+Dumping `environ' as pure does not work! So, to use remapping,
+you must write a startup routine for your machine in Emacs's crt0.c.
+If NO_REMAP is defined, Emacs uses the system's crt0.o.
+
+* SECTION_ALIGNMENT
+
+Some machines that use COFF executables require that each section
+start on a certain boundary *in the COFF file*. Such machines should
+define SECTION_ALIGNMENT to a mask of the low-order bits that must be
+zero on such a boundary. This mask is used to control padding between
+segments in the COFF file.
+
+If SECTION_ALIGNMENT is not defined, the segments are written
+consecutively with no attempt at alignment. This is right for
+unmodified system V.
+
+* SEGMENT_MASK
+
+Some machines require that the beginnings and ends of segments
+*in core* be on certain boundaries. For most machines, a page
+boundary is sufficient. That is the default. When a larger
+boundary is needed, define SEGMENT_MASK to a mask of
+the bits that must be zero on such a boundary.
+
+* A_TEXT_OFFSET(HDR)
+
+Some machines count the a.out header as part of the size of the text
+segment (a_text); they may actually load the header into core as the
+first data in the text segment. Some have additional padding between
+the header and the real text of the program that is counted in a_text.
+
+For these machines, define A_TEXT_OFFSET(HDR) to examine the header
+structure HDR and return the number of bytes to add to `a_text'
+before writing it (above and beyond the number of bytes of actual
+program text). HDR's standard fields are already correct, except that
+this adjustment to the `a_text' field has not yet been made;
+thus, the amount of offset can depend on the data in the file.
+
+* A_TEXT_SEEK(HDR)
+
+If defined, this macro specifies the number of bytes to seek into the
+a.out file before starting to write the text segment.
+
+* EXEC_MAGIC
+
+For machines using COFF, this macro, if defined, is a value stored
+into the magic number field of the output file.
+
+* ADJUST_EXEC_HEADER
+
+This macro can be used to generate statements to adjust or
+initialize nonstandard fields in the file header
+
+* ADDR_CORRECT(ADDR)
+
+Macro to correct an int which is the bit pattern of a pointer to a byte
+into an int which is the number of a byte.
+
+This macro has a default definition which is usually right.
+This default definition is a no-op on most machines (where a
+pointer looks like an int) but not on all machines.
+
+*/
+
+#ifndef emacs
+#define PERROR(arg) perror (arg); return -1
+#else
+#define IN_UNEXEC
+#include <config.h>
+#define PERROR(file) report_error (file, new)
+#endif
+
+#ifndef CANNOT_DUMP /* all rest of file! */
+
+#ifdef COFF_ENCAPSULATE
+int need_coff_header = 1;
+#include <coff-encap/a.out.encap.h> /* The location might be a poor assumption */
+#else
+#ifdef MSDOS
+#if __DJGPP__ > 1
+#include <fcntl.h> /* for O_RDONLY, O_RDWR */
+#include <crt0.h> /* for _crt0_startup_flags and its bits */
+static int save_djgpp_startup_flags;
+#endif
+#include <coff.h>
+#define filehdr external_filehdr
+#define scnhdr external_scnhdr
+#define syment external_syment
+#define auxent external_auxent
+#define n_numaux e_numaux
+#define n_type e_type
+struct aouthdr
+{
+ unsigned short magic; /* type of file */
+ unsigned short vstamp; /* version stamp */
+ unsigned long tsize; /* text size in bytes, padded to FW bdry*/
+ unsigned long dsize; /* initialized data " " */
+ unsigned long bsize; /* uninitialized data " " */
+ unsigned long entry; /* entry pt. */
+ unsigned long text_start;/* base of text used for this file */
+ unsigned long data_start;/* base of data used for this file */
+};
+
+
+#else /* not MSDOS */
+#include <a.out.h>
+#endif /* not MSDOS */
+#endif
+
+/* Define getpagesize if the system does not.
+ Note that this may depend on symbols defined in a.out.h. */
+#include "getpagesize.h"
+
+#ifndef makedev /* Try to detect types.h already loaded */
+#include <sys/types.h>
+#endif /* makedev */
+#include <stdio.h>
+#include <sys/stat.h>
+#include <errno.h>
+
+#include <sys/file.h> /* Must be after sys/types.h for USG and BSD4_1*/
+
+#ifdef USG5
+#include <fcntl.h>
+#endif
+
+#ifndef O_RDONLY
+#define O_RDONLY 0
+#endif
+#ifndef O_RDWR
+#define O_RDWR 2
+#endif
+
+
+extern char *start_of_text (); /* Start of text */
+extern char *start_of_data (); /* Start of initialized data */
+
+#ifdef COFF
+static long block_copy_start; /* Old executable start point */
+static struct filehdr f_hdr; /* File header */
+static struct aouthdr f_ohdr; /* Optional file header (a.out) */
+long bias; /* Bias to add for growth */
+long lnnoptr; /* Pointer to line-number info within file */
+#define SYMS_START block_copy_start
+
+static long text_scnptr;
+static long data_scnptr;
+
+#else /* not COFF */
+
+#ifdef HPUX
+extern void *sbrk ();
+#else
+#if 0
+/* Some systems with __STDC__ compilers still declare this `char *' in some
+ header file, and our declaration conflicts. The return value is always
+ cast, so it should be harmless to leave it undefined. Hopefully
+ machines with different size pointers and ints declare sbrk in a header
+ file. */
+#ifdef __STDC__
+extern void *sbrk ();
+#else
+extern char *sbrk ();
+#endif /* __STDC__ */
+#endif
+#endif /* HPUX */
+
+#define SYMS_START ((long) N_SYMOFF (ohdr))
+
+/* Some machines override the structure name for an a.out header. */
+#ifndef EXEC_HDR_TYPE
+#define EXEC_HDR_TYPE struct exec
+#endif
+
+#ifdef HPUX
+#ifdef HP9000S200_ID
+#define MY_ID HP9000S200_ID
+#else
+#include <model.h>
+#define MY_ID MYSYS
+#endif /* no HP9000S200_ID */
+static MAGIC OLDMAGIC = {MY_ID, SHARE_MAGIC};
+static MAGIC NEWMAGIC = {MY_ID, DEMAND_MAGIC};
+#define N_TXTOFF(x) TEXT_OFFSET(x)
+#define N_SYMOFF(x) LESYM_OFFSET(x)
+static EXEC_HDR_TYPE hdr, ohdr;
+
+#else /* not HPUX */
+
+#if defined (USG) && !defined (IBMAIX) && !defined (IRIS) && !defined (COFF_ENCAPSULATE) && !defined (LINUX)
+static struct bhdr hdr, ohdr;
+#define a_magic fmagic
+#define a_text tsize
+#define a_data dsize
+#define a_bss bsize
+#define a_syms ssize
+#define a_trsize rtsize
+#define a_drsize rdsize
+#define a_entry entry
+#define N_BADMAG(x) \
+ (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\
+ ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC)
+#define NEWMAGIC FMAGIC
+#else /* IRIS or IBMAIX or not USG */
+static EXEC_HDR_TYPE hdr, ohdr;
+#define NEWMAGIC ZMAGIC
+#endif /* IRIS or IBMAIX not USG */
+#endif /* not HPUX */
+
+static int unexec_text_start;
+static int unexec_data_start;
+
+#ifdef COFF_ENCAPSULATE
+/* coffheader is defined in the GNU a.out.encap.h file. */
+struct coffheader coffheader;
+#endif
+
+#endif /* not COFF */
+
+static int pagemask;
+
+/* Correct an int which is the bit pattern of a pointer to a byte
+ into an int which is the number of a byte.
+ This is a no-op on ordinary machines, but not on all. */
+
+#ifndef ADDR_CORRECT /* Let m-*.h files override this definition */
+#define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
+#endif
+
+#ifdef emacs
+
+#include "lisp.h"
+
+static
+report_error (file, fd)
+ char *file;
+ int fd;
+{
+ if (fd)
+ close (fd);
+ report_file_error ("Cannot unexec", Fcons (build_string (file), Qnil));
+}
+#endif /* emacs */
+
+#define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1
+#define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1
+#define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1
+
+static
+report_error_1 (fd, msg, a1, a2)
+ int fd;
+ char *msg;
+ int a1, a2;
+{
+ close (fd);
+#ifdef emacs
+ error (msg, a1, a2);
+#else
+ fprintf (stderr, msg, a1, a2);
+ fprintf (stderr, "\n");
+#endif
+}
+
+static int make_hdr ();
+static int copy_text_and_data ();
+static int copy_sym ();
+static void mark_x ();
+
+/* ****************************************************************
+ * unexec
+ *
+ * driving logic.
+ */
+unexec (new_name, a_name, data_start, bss_start, entry_address)
+ char *new_name, *a_name;
+ unsigned data_start, bss_start, entry_address;
+{
+ int new, a_out = -1;
+
+ if (a_name && (a_out = open (a_name, O_RDONLY)) < 0)
+ {
+ PERROR (a_name);
+ }
+ if ((new = creat (new_name, 0666)) < 0)
+ {
+ PERROR (new_name);
+ }
+
+ if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0
+ || copy_text_and_data (new, a_out) < 0
+ || copy_sym (new, a_out, a_name, new_name) < 0
+#ifdef COFF
+#ifndef COFF_BSD_SYMBOLS
+ || adjust_lnnoptrs (new, a_out, new_name) < 0
+#endif
+#endif
+ )
+ {
+ close (new);
+ /* unlink (new_name); /* Failed, unlink new a.out */
+ return -1;
+ }
+
+ close (new);
+ if (a_out >= 0)
+ close (a_out);
+ mark_x (new_name);
+ return 0;
+}
+
+/* ****************************************************************
+ * make_hdr
+ *
+ * Make the header in the new a.out from the header in core.
+ * Modify the text and data sizes.
+ */
+static int
+make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name)
+ int new, a_out;
+ unsigned data_start, bss_start, entry_address;
+ char *a_name;
+ char *new_name;
+{
+ int tem;
+#ifdef COFF
+ auto struct scnhdr f_thdr; /* Text section header */
+ auto struct scnhdr f_dhdr; /* Data section header */
+ auto struct scnhdr f_bhdr; /* Bss section header */
+ auto struct scnhdr scntemp; /* Temporary section header */
+ register int scns;
+#endif /* COFF */
+#ifdef USG_SHARED_LIBRARIES
+ extern unsigned int bss_end;
+#else
+ unsigned int bss_end;
+#endif
+
+ pagemask = getpagesize () - 1;
+
+ /* Adjust text/data boundary. */
+#ifdef NO_REMAP
+ data_start = (int) start_of_data ();
+#else /* not NO_REMAP */
+ if (!data_start)
+ data_start = (int) start_of_data ();
+#endif /* not NO_REMAP */
+ data_start = ADDR_CORRECT (data_start);
+
+#ifdef SEGMENT_MASK
+ data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */
+#else
+ data_start = data_start & ~pagemask; /* (Down) to page boundary. */
+#endif
+
+ bss_end = ADDR_CORRECT (sbrk (0)) + pagemask;
+ bss_end &= ~ pagemask;
+
+ /* Adjust data/bss boundary. */
+ if (bss_start != 0)
+ {
+ bss_start = (ADDR_CORRECT (bss_start) + pagemask);
+ /* (Up) to page bdry. */
+ bss_start &= ~ pagemask;
+ if (bss_start > bss_end)
+ {
+ ERROR1 ("unexec: Specified bss_start (%u) is past end of program",
+ bss_start);
+ }
+ }
+ else
+ bss_start = bss_end;
+
+ if (data_start > bss_start) /* Can't have negative data size. */
+ {
+ ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)",
+ data_start, bss_start);
+ }
+
+#ifdef COFF
+ /* Salvage as much info from the existing file as possible */
+ if (a_out >= 0)
+ {
+ if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
+ {
+ PERROR (a_name);
+ }
+ block_copy_start += sizeof (f_hdr);
+ if (f_hdr.f_opthdr > 0)
+ {
+ if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
+ {
+ PERROR (a_name);
+ }
+ block_copy_start += sizeof (f_ohdr);
+ }
+ /* Loop through section headers, copying them in */
+ lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
+ for (scns = f_hdr.f_nscns; scns > 0; scns--) {
+ if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
+ {
+ PERROR (a_name);
+ }
+ if (scntemp.s_scnptr > 0L)
+ {
+ if (block_copy_start < scntemp.s_scnptr + scntemp.s_size)
+ block_copy_start = scntemp.s_scnptr + scntemp.s_size;
+ }
+ if (strcmp (scntemp.s_name, ".text") == 0)
+ {
+ f_thdr = scntemp;
+ }
+ else if (strcmp (scntemp.s_name, ".data") == 0)
+ {
+ f_dhdr = scntemp;
+ }
+ else if (strcmp (scntemp.s_name, ".bss") == 0)
+ {
+ f_bhdr = scntemp;
+ }
+ }
+ }
+ else
+ {
+ ERROR0 ("can't build a COFF file from scratch yet");
+ }
+
+ /* Now we alter the contents of all the f_*hdr variables
+ to correspond to what we want to dump. */
+
+#ifdef USG_SHARED_LIBRARIES
+
+ /* The amount of data we're adding to the file is distance from the
+ * end of the original .data space to the current end of the .data
+ * space.
+ */
+
+ bias = bss_start - (f_ohdr.data_start + f_dhdr.s_size);
+
+#endif
+
+ f_hdr.f_flags |= (F_RELFLG | F_EXEC);
+#ifdef TPIX
+ f_hdr.f_nscns = 3;
+#endif
+#ifdef EXEC_MAGIC
+ f_ohdr.magic = EXEC_MAGIC;
+#endif
+#ifndef NO_REMAP
+ f_ohdr.text_start = (long) start_of_text ();
+ f_ohdr.tsize = data_start - f_ohdr.text_start;
+ f_ohdr.data_start = data_start;
+#endif /* NO_REMAP */
+ f_ohdr.dsize = bss_start - f_ohdr.data_start;
+ f_ohdr.bsize = bss_end - bss_start;
+#ifndef KEEP_OLD_TEXT_SCNPTR
+ /* On some machines, the old values are right.
+ ??? Maybe on all machines with NO_REMAP. */
+ f_thdr.s_size = f_ohdr.tsize;
+ f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr);
+ f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr));
+#endif /* KEEP_OLD_TEXT_SCNPTR */
+#ifdef ADJUST_TEXT_SCNHDR_SIZE
+ /* On some machines, `text size' includes all headers. */
+ f_thdr.s_size -= f_thdr.s_scnptr;
+#endif /* ADJUST_TEST_SCNHDR_SIZE */
+ lnnoptr = f_thdr.s_lnnoptr;
+#ifdef SECTION_ALIGNMENT
+ /* Some systems require special alignment
+ of the sections in the file itself. */
+ f_thdr.s_scnptr
+ = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
+#endif /* SECTION_ALIGNMENT */
+#ifdef TPIX
+ f_thdr.s_scnptr = 0xd0;
+#endif
+ text_scnptr = f_thdr.s_scnptr;
+#ifdef ADJUST_TEXTBASE
+ text_scnptr = sizeof (f_hdr) + sizeof (f_ohdr) + (f_hdr.f_nscns) * (sizeof (f_thdr));
+#endif
+#ifndef KEEP_OLD_PADDR
+ f_dhdr.s_paddr = f_ohdr.data_start;
+#endif /* KEEP_OLD_PADDR */
+ f_dhdr.s_vaddr = f_ohdr.data_start;
+ f_dhdr.s_size = f_ohdr.dsize;
+ f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size;
+#ifdef SECTION_ALIGNMENT
+ /* Some systems require special alignment
+ of the sections in the file itself. */
+ f_dhdr.s_scnptr
+ = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT;
+#endif /* SECTION_ALIGNMENT */
+#ifdef DATA_SECTION_ALIGNMENT
+ /* Some systems require special alignment
+ of the data section only. */
+ f_dhdr.s_scnptr
+ = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT;
+#endif /* DATA_SECTION_ALIGNMENT */
+ data_scnptr = f_dhdr.s_scnptr;
+#ifndef KEEP_OLD_PADDR
+ f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize;
+#endif /* KEEP_OLD_PADDR */
+ f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
+ f_bhdr.s_size = f_ohdr.bsize;
+ f_bhdr.s_scnptr = 0L;
+#ifndef USG_SHARED_LIBRARIES
+ bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;
+#endif
+
+ if (f_hdr.f_symptr > 0L)
+ {
+ f_hdr.f_symptr += bias;
+ }
+
+ if (f_thdr.s_lnnoptr > 0L)
+ {
+ f_thdr.s_lnnoptr += bias;
+ }
+
+#ifdef ADJUST_EXEC_HEADER
+ ADJUST_EXEC_HEADER;
+#endif /* ADJUST_EXEC_HEADER */
+
+ if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr))
+ {
+ PERROR (new_name);
+ }
+
+#ifndef USG_SHARED_LIBRARIES
+
+ if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
+ {
+ PERROR (new_name);
+ }
+
+ if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
+ {
+ PERROR (new_name);
+ }
+
+#else /* USG_SHARED_LIBRARIES */
+
+ /* The purpose of this code is to write out the new file's section
+ * header table.
+ *
+ * Scan through the original file's sections. If the encountered
+ * section is one we know (.text, .data or .bss), write out the
+ * correct header. If it is a section we do not know (such as
+ * .lib), adjust the address of where the section data is in the
+ * file, and write out the header.
+ *
+ * If any section precedes .text or .data in the file, this code
+ * will not adjust the file pointer for that section correctly.
+ */
+
+ /* This used to use sizeof (f_ohdr) instead of .f_opthdr.
+ .f_opthdr is said to be right when there is no optional header. */
+ lseek (a_out, sizeof (f_hdr) + f_hdr.f_opthdr, 0);
+
+ for (scns = f_hdr.f_nscns; scns > 0; scns--)
+ {
+ if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
+ PERROR (a_name);
+
+ if (!strcmp (scntemp.s_name, f_thdr.s_name)) /* .text */
+ {
+ if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr))
+ PERROR (new_name);
+ }
+ else if (!strcmp (scntemp.s_name, f_dhdr.s_name)) /* .data */
+ {
+ if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr))
+ PERROR (new_name);
+ }
+ else if (!strcmp (scntemp.s_name, f_bhdr.s_name)) /* .bss */
+ {
+ if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr))
+ PERROR (new_name);
+ }
+ else
+ {
+ if (scntemp.s_scnptr)
+ scntemp.s_scnptr += bias;
+ if (write (new, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
+ PERROR (new_name);
+ }
+ }
+#endif /* USG_SHARED_LIBRARIES */
+
+ return (0);
+
+#else /* if not COFF */
+
+ /* Get symbol table info from header of a.out file if given one. */
+ if (a_out >= 0)
+ {
+#ifdef COFF_ENCAPSULATE
+ if (read (a_out, &coffheader, sizeof coffheader) != sizeof coffheader)
+ {
+ PERROR(a_name);
+ }
+ if (coffheader.f_magic != COFF_MAGIC)
+ {
+ ERROR1("%s doesn't have legal coff magic number\n", a_name);
+ }
+#endif
+ if (read (a_out, &ohdr, sizeof hdr) != sizeof hdr)
+ {
+ PERROR (a_name);
+ }
+
+ if (N_BADMAG (ohdr))
+ {
+ ERROR1 ("invalid magic number in %s", a_name);
+ }
+ hdr = ohdr;
+ }
+ else
+ {
+#ifdef COFF_ENCAPSULATE
+ /* We probably could without too much trouble. The code is in gld
+ * but I don't have that much time or incentive.
+ */
+ ERROR0 ("can't build a COFF file from scratch yet");
+#else
+#ifdef MSDOS /* Demacs 1.1.1 91/10/16 HIRANO Satoshi */
+ bzero ((void *)&hdr, sizeof hdr);
+#else
+ bzero (&hdr, sizeof hdr);
+#endif
+#endif
+ }
+
+ unexec_text_start = (long) start_of_text ();
+ unexec_data_start = data_start;
+
+ /* Machine-dependent fixup for header, or maybe for unexec_text_start */
+#ifdef ADJUST_EXEC_HEADER
+ ADJUST_EXEC_HEADER;
+#endif /* ADJUST_EXEC_HEADER */
+
+ hdr.a_trsize = 0;
+ hdr.a_drsize = 0;
+ if (entry_address != 0)
+ hdr.a_entry = entry_address;
+
+ hdr.a_bss = bss_end - bss_start;
+ hdr.a_data = bss_start - data_start;
+#ifdef NO_REMAP
+ hdr.a_text = ohdr.a_text;
+#else /* not NO_REMAP */
+ hdr.a_text = data_start - unexec_text_start;
+
+#ifdef A_TEXT_OFFSET
+ hdr.a_text += A_TEXT_OFFSET (ohdr);
+#endif
+
+#endif /* not NO_REMAP */
+
+#ifdef COFF_ENCAPSULATE
+ /* We are encapsulating BSD format within COFF format. */
+ {
+ struct coffscn *tp, *dp, *bp;
+ tp = &coffheader.scns[0];
+ dp = &coffheader.scns[1];
+ bp = &coffheader.scns[2];
+ tp->s_size = hdr.a_text + sizeof(struct exec);
+ dp->s_paddr = data_start;
+ dp->s_vaddr = data_start;
+ dp->s_size = hdr.a_data;
+ bp->s_paddr = dp->s_vaddr + dp->s_size;
+ bp->s_vaddr = bp->s_paddr;
+ bp->s_size = hdr.a_bss;
+ coffheader.tsize = tp->s_size;
+ coffheader.dsize = dp->s_size;
+ coffheader.bsize = bp->s_size;
+ coffheader.text_start = tp->s_vaddr;
+ coffheader.data_start = dp->s_vaddr;
+ }
+ if (write (new, &coffheader, sizeof coffheader) != sizeof coffheader)
+ {
+ PERROR(new_name);
+ }
+#endif /* COFF_ENCAPSULATE */
+
+ if (write (new, &hdr, sizeof hdr) != sizeof hdr)
+ {
+ PERROR (new_name);
+ }
+
+#if 0 /* This #ifndef caused a bug on Linux when using QMAGIC. */
+ /* This adjustment was done above only #ifndef NO_REMAP,
+ so only undo it now #ifndef NO_REMAP. */
+ /* #ifndef NO_REMAP */
+#endif
+#ifdef A_TEXT_OFFSET
+ hdr.a_text -= A_TEXT_OFFSET (ohdr);
+#endif
+
+ return 0;
+
+#endif /* not COFF */
+}
+
+/* ****************************************************************
+ * copy_text_and_data
+ *
+ * Copy the text and data segments from memory to the new a.out
+ */
+static int
+copy_text_and_data (new, a_out)
+ int new, a_out;
+{
+ register char *end;
+ register char *ptr;
+
+#ifdef COFF
+
+#ifdef USG_SHARED_LIBRARIES
+
+ int scns;
+ struct scnhdr scntemp; /* Temporary section header */
+
+ /* The purpose of this code is to write out the new file's section
+ * contents.
+ *
+ * Step through the section table. If we know the section (.text,
+ * .data) do the appropriate thing. Otherwise, if the section has
+ * no allocated space in the file (.bss), do nothing. Otherwise,
+ * the section has space allocated in the file, and is not a section
+ * we know. So just copy it.
+ */
+
+ lseek (a_out, sizeof (struct filehdr) + sizeof (struct aouthdr), 0);
+
+ for (scns = f_hdr.f_nscns; scns > 0; scns--)
+ {
+ if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp))
+ PERROR ("temacs");
+
+ if (!strcmp (scntemp.s_name, ".text"))
+ {
+ lseek (new, (long) text_scnptr, 0);
+ ptr = (char *) f_ohdr.text_start;
+ end = ptr + f_ohdr.tsize;
+ write_segment (new, ptr, end);
+ }
+ else if (!strcmp (scntemp.s_name, ".data"))
+ {
+ lseek (new, (long) data_scnptr, 0);
+ ptr = (char *) f_ohdr.data_start;
+ end = ptr + f_ohdr.dsize;
+ write_segment (new, ptr, end);
+ }
+ else if (!scntemp.s_scnptr)
+ ; /* do nothing - no data for this section */
+ else
+ {
+ char page[BUFSIZ];
+ int size, n;
+ long old_a_out_ptr = lseek (a_out, 0, 1);
+
+ lseek (a_out, scntemp.s_scnptr, 0);
+ for (size = scntemp.s_size; size > 0; size -= sizeof (page))
+ {
+ n = size > sizeof (page) ? sizeof (page) : size;
+ if (read (a_out, page, n) != n || write (new, page, n) != n)
+ PERROR ("emacs");
+ }
+ lseek (a_out, old_a_out_ptr, 0);
+ }
+ }
+
+#else /* COFF, but not USG_SHARED_LIBRARIES */
+
+#ifdef MSDOS
+#if __DJGPP__ >= 2
+ /* Dump the original table of exception handlers, not the one
+ where our exception hooks are registered. */
+ __djgpp_exception_toggle ();
+
+ /* Switch off startup flags that might have been set at runtime
+ and which might change the way that dumped Emacs works. */
+ save_djgpp_startup_flags = _crt0_startup_flags;
+ _crt0_startup_flags &= ~(_CRT0_FLAG_NO_LFN | _CRT0_FLAG_NEARPTR);
+#endif
+#endif
+
+ lseek (new, (long) text_scnptr, 0);
+ ptr = (char *) f_ohdr.text_start;
+#ifdef HEADER_INCL_IN_TEXT
+ /* For Gould UTX/32, text starts after headers */
+ ptr = (char *) (ptr + text_scnptr);
+#endif /* HEADER_INCL_IN_TEXT */
+ end = ptr + f_ohdr.tsize;
+ write_segment (new, ptr, end);
+
+ lseek (new, (long) data_scnptr, 0);
+ ptr = (char *) f_ohdr.data_start;
+ end = ptr + f_ohdr.dsize;
+ write_segment (new, ptr, end);
+
+#ifdef MSDOS
+#if __DJGPP__ >= 2
+ /* Restore our exception hooks. */
+ __djgpp_exception_toggle ();
+
+ /* Restore the startup flags. */
+ _crt0_startup_flags = save_djgpp_startup_flags;
+#endif
+#endif
+
+#endif /* USG_SHARED_LIBRARIES */
+
+#else /* if not COFF */
+
+/* Some machines count the header as part of the text segment.
+ That is to say, the header appears in core
+ just before the address that start_of_text returns.
+ For them, N_TXTOFF is the place where the header goes.
+ We must adjust the seek to the place after the header.
+ Note that at this point hdr.a_text does *not* count
+ the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */
+
+#ifdef A_TEXT_SEEK
+ lseek (new, (long) A_TEXT_SEEK (hdr), 0);
+#else
+ lseek (new, (long) N_TXTOFF (hdr), 0);
+#endif /* no A_TEXT_SEEK */
+
+#ifdef RISCiX
+
+ /* Acorn's RISC-iX has a wacky way of initialising the position of the heap.
+ * There is a little table in crt0.o that is filled at link time with
+ * the min and current brk positions, among other things. When start
+ * runs, it copies the table to where these parameters live during
+ * execution. This data is in text space, so it cannot be modified here
+ * before saving the executable, so the data is written manually. In
+ * addition, the table does not have a label, and the nearest accessible
+ * label (mcount) is not prefixed with a '_', thus making it inaccessible
+ * from within C programs. To overcome this, emacs's executable is passed
+ * through the command 'nm %s | fgrep mcount' into a pipe, and the
+ * resultant output is then used to find the address of 'mcount'. As far as
+ * is possible to determine, in RISC-iX releases prior to 1.2, the negative
+ * offset of the table from mcount is 0x2c, whereas from 1.2 onwards it is
+ * 0x30. bss_end has been rounded up to page boundary. This solution is
+ * based on suggestions made by Kevin Welton and Steve Hunt of Acorn, and
+ * avoids the need for a custom version of crt0.o for emacs which has its
+ * table in data space.
+ */
+
+ {
+ char command[1024];
+ char errbuf[1024];
+ char address_text[32];
+ int proforma[4];
+ FILE *pfile;
+ char *temp_ptr;
+ char c;
+ int mcount_address, mcount_offset, count;
+ extern char *_execname;
+
+
+ /* The use of _execname is incompatible with RISCiX 1.1 */
+ sprintf (command, "nm %s | fgrep mcount", _execname);
+
+ if ( (pfile = popen(command, "r")) == NULL)
+ {
+ sprintf (errbuf, "Could not open pipe");
+ PERROR (errbuf);
+ }
+
+ count=0;
+ while ( ((c=getc(pfile)) != EOF) && (c != ' ') && (count < 31))
+ address_text[count++]=c;
+ address_text[count]=0;
+
+ if ((count == 0) || pclose(pfile) != NULL)
+ {
+ sprintf (errbuf, "Failed to execute the command '%s'\n", command);
+ PERROR (errbuf);
+ }
+
+ sscanf(address_text, "%x", &mcount_address);
+ ptr = (char *) unexec_text_start;
+ mcount_offset = (char *)mcount_address - ptr;
+
+#ifdef RISCiX_1_1
+#define EDATA_OFFSET 0x2c
+#else
+#define EDATA_OFFSET 0x30
+#endif
+
+ end = ptr + mcount_offset - EDATA_OFFSET;
+
+ write_segment (new, ptr, end);
+
+ proforma[0] = bss_end; /* becomes _edata */
+ proforma[1] = bss_end; /* becomes _end */
+ proforma[2] = bss_end; /* becomes _minbrk */
+ proforma[3] = bss_end; /* becomes _curbrk */
+
+ write (new, proforma, 16);
+
+ temp_ptr = ptr;
+ ptr = end + 16;
+ end = temp_ptr + hdr.a_text;
+
+ write_segment (new, ptr, end);
+ }
+
+#else /* !RISCiX */
+ ptr = (char *) unexec_text_start;
+ end = ptr + hdr.a_text;
+ write_segment (new, ptr, end);
+#endif /* RISCiX */
+
+ ptr = (char *) unexec_data_start;
+ end = ptr + hdr.a_data;
+/* This lseek is certainly incorrect when A_TEXT_OFFSET
+ and I believe it is a no-op otherwise.
+ Let's see if its absence ever fails. */
+/* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */
+ write_segment (new, ptr, end);
+
+#endif /* not COFF */
+
+ return 0;
+}
+
+write_segment (new, ptr, end)
+ int new;
+ register char *ptr, *end;
+{
+ register int i, nwrite, ret;
+ char buf[80];
+ extern int errno;
+ /* This is the normal amount to write at once.
+ It is the size of block that NFS uses. */
+ int writesize = 1 << 13;
+ int pagesize = getpagesize ();
+ char zeros[1 << 13];
+
+ bzero (zeros, sizeof (zeros));
+
+ for (i = 0; ptr < end;)
+ {
+ /* Distance to next multiple of writesize. */
+ nwrite = (((int) ptr + writesize) & -writesize) - (int) ptr;
+ /* But not beyond specified end. */
+ if (nwrite > end - ptr) nwrite = end - ptr;
+ ret = write (new, ptr, nwrite);
+ /* If write gets a page fault, it means we reached
+ a gap between the old text segment and the old data segment.
+ This gap has probably been remapped into part of the text segment.
+ So write zeros for it. */
+ if (ret == -1
+#ifdef EFAULT
+ && errno == EFAULT
+#endif
+ )
+ {
+ /* Write only a page of zeros at once,
+ so that we we don't overshoot the start
+ of the valid memory in the old data segment. */
+ if (nwrite > pagesize)
+ nwrite = pagesize;
+ write (new, zeros, nwrite);
+ }
+#if 0 /* Now that we have can ask `write' to write more than a page,
+ it is legit for write do less than the whole amount specified. */
+ else if (nwrite != ret)
+ {
+ sprintf (buf,
+ "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d",
+ ptr, new, nwrite, ret, errno);
+ PERROR (buf);
+ }
+#endif
+ i += nwrite;
+ ptr += nwrite;
+ }
+}
+
+/* ****************************************************************
+ * copy_sym
+ *
+ * Copy the relocation information and symbol table from the a.out to the new
+ */
+static int
+copy_sym (new, a_out, a_name, new_name)
+ int new, a_out;
+ char *a_name, *new_name;
+{
+ char page[1024];
+ int n;
+
+ if (a_out < 0)
+ return 0;
+
+#ifdef COFF
+ if (SYMS_START == 0L)
+ return 0;
+#endif /* COFF */
+
+#ifdef COFF
+ if (lnnoptr) /* if there is line number info */
+ lseek (a_out, lnnoptr, 0); /* start copying from there */
+ else
+#endif /* COFF */
+ lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */
+
+ while ((n = read (a_out, page, sizeof page)) > 0)
+ {
+ if (write (new, page, n) != n)
+ {
+ PERROR (new_name);
+ }
+ }
+ if (n < 0)
+ {
+ PERROR (a_name);
+ }
+ return 0;
+}
+
+/* ****************************************************************
+ * mark_x
+ *
+ * After successfully building the new a.out, mark it executable
+ */
+static void
+mark_x (name)
+ char *name;
+{
+ struct stat sbuf;
+ int um;
+ int new = 0; /* for PERROR */
+
+ um = umask (777);
+ umask (um);
+ if (stat (name, &sbuf) == -1)
+ {
+ PERROR (name);
+ }
+ sbuf.st_mode |= 0111 & ~um;
+ if (chmod (name, sbuf.st_mode) == -1)
+ PERROR (name);
+}
+
+#ifdef COFF
+#ifndef COFF_BSD_SYMBOLS
+
+/*
+ * If the COFF file contains a symbol table and a line number section,
+ * then any auxiliary entries that have values for x_lnnoptr must
+ * be adjusted by the amount that the line number section has moved
+ * in the file (bias computed in make_hdr). The #@$%&* designers of
+ * the auxiliary entry structures used the absolute file offsets for
+ * the line number entry rather than an offset from the start of the
+ * line number section!
+ *
+ * When I figure out how to scan through the symbol table and pick out
+ * the auxiliary entries that need adjustment, this routine will
+ * be fixed. As it is now, all such entries are wrong and sdb
+ * will complain. Fred Fish, UniSoft Systems Inc.
+ */
+
+/* This function is probably very slow. Instead of reopening the new
+ file for input and output it should copy from the old to the new
+ using the two descriptors already open (WRITEDESC and READDESC).
+ Instead of reading one small structure at a time it should use
+ a reasonable size buffer. But I don't have time to work on such
+ things, so I am installing it as submitted to me. -- RMS. */
+
+adjust_lnnoptrs (writedesc, readdesc, new_name)
+ int writedesc;
+ int readdesc;
+ char *new_name;
+{
+ register int nsyms;
+ register int new;
+#if defined (amdahl_uts) || defined (pfa)
+ SYMENT symentry;
+ AUXENT auxentry;
+#else
+ struct syment symentry;
+ union auxent auxentry;
+#endif
+
+ if (!lnnoptr || !f_hdr.f_symptr)
+ return 0;
+
+#ifdef MSDOS
+ if ((new = writedesc) < 0)
+#else
+ if ((new = open (new_name, O_RDWR)) < 0)
+#endif
+ {
+ PERROR (new_name);
+ return -1;
+ }
+
+ lseek (new, f_hdr.f_symptr, 0);
+ for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++)
+ {
+ read (new, &symentry, SYMESZ);
+ if (symentry.n_numaux)
+ {
+ read (new, &auxentry, AUXESZ);
+ nsyms++;
+ if (ISFCN (symentry.n_type) || symentry.n_type == 0x2400)
+ {
+ auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias;
+ lseek (new, -AUXESZ, 1);
+ write (new, &auxentry, AUXESZ);
+ }
+ }
+ }
+#ifndef MSDOS
+ close (new);
+#endif
+ return 0;
+}
+
+#endif /* COFF_BSD_SYMBOLS */
+
+#endif /* COFF */
+
+#endif /* not CANNOT_DUMP */