Rename src/unexec.c => src/unexcoff.c.

 src/unexcoff.c: Renamed from unexec.c.
 src/deps.mk (unexcoff.o): Rename unexec.[co] => unexcoff.[co].
 configure.in (UNEXEC_OBJ): Rename unexec.o => unexcoff.o.
 admin/MAINTAINERS: Rename src/unexec.c => src/unexcoff.c.
 etc/AUTHORS: Rename unexec.o => unexcoff.o.
 etc/PROBLEMS: Rename unexec.o => unex*.o.
 lisp/emacs-lisp/find-gc.el (find-gc-source-files): Rename
 unexec.c => unexcoff.c.
 lisp/emacs-lisp/authors.el (authors-fixed-entries): Rename
 unexec.c => unexcoff.c.
 msdos/sed1v2.inp (UNEXEC_OBJ): Edit to unexcoff.o, due to renaming of
 unexec.c => unexcoff.c.

1 files changed, 665 insertions, 0 deletions

diff --git a/src/unexcoff.c b/src/unexcoff.c
new file mode 100644
index 00000000000..ed319ec8e7f
--- /dev/null
+++ b/src/unexcoff.c
@@ -0,0 +1,665 @@
+/* Copyright (C) 1985, 1986, 1987, 1988, 1992, 1993, 1994, 2001, 2002, 2003,
+                 2004, 2005, 2006, 2007, 2008, 2009, 2010  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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.  */
+
+
+/*
+ * unexcoff.c - Convert a running program into an a.out or COFF file.
+ *
+ * ==================================================================
+ * Note: This file is currently used only by the MSDOS (a.k.a. DJGPP)
+ * build of Emacs.  If you are not interested in the MSDOS build, you
+ * are looking at the wrong version of unexec!
+ * ==================================================================
+ *
+ * Author:	Spencer W. Thomas
+ * 		Computer Science Dept.
+ * 		University of Utah
+ * Date:	Tue Mar  2 1982
+ * Originally under the name unexec.c.
+ * 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.
+ *
+ * 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.
+ */
+
+#ifndef emacs
+#define PERROR(arg) perror (arg); return -1
+#else
+#include <config.h>
+#define PERROR(file) report_error (file, new)
+#endif
+
+#ifndef CANNOT_DUMP  /* all rest of file!  */
+
+#ifdef HAVE_COFF_H
+#include <coff.h>
+#ifdef MSDOS
+#include <fcntl.h>  /* for O_RDONLY, O_RDWR */
+#include <crt0.h>   /* for _crt0_startup_flags and its bits */
+static int save_djgpp_startup_flags;
+#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 */
+};
+#endif /* not MSDOS */
+#else  /* not HAVE_COFF_H */
+#include <a.out.h>
+#endif /* not HAVE_COFF_H */
+
+/* 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>
+
+#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 */
+
+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;
+
+static long coff_offset;
+
+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.  */
+
+#define ADDR_CORRECT(x) ((char *)(x) - (char*)0)
+
+#ifdef emacs
+
+#include <setjmp.h>
+#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 ();
+
+/* ****************************************************************
+ * 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;
+  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;
+  unsigned int bss_end;
+
+  pagemask = getpagesize () - 1;
+
+  /* Adjust text/data boundary. */
+  data_start = (int) start_of_data ();
+  data_start = ADDR_CORRECT (data_start);
+  data_start = data_start & ~pagemask; /* (Down) to page boundary. */
+
+  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);
+    }
+
+  coff_offset = 0L;		/* stays zero, except in DJGPP */
+
+  /* Salvage as much info from the existing file as possible */
+  if (a_out >= 0)
+    {
+#ifdef MSDOS
+      /* Support the coff-go32-exe format with a prepended stub, since
+	 this is what GCC 2.8.0 and later generates by default in DJGPP.  */
+      unsigned short mz_header[3];
+
+      if (read (a_out, &mz_header, sizeof (mz_header)) != sizeof (mz_header))
+	{
+	  PERROR (a_name);
+	}
+      if (mz_header[0] == 0x5a4d || mz_header[0] == 0x4d5a) /* "MZ" or "ZM" */
+	{
+	  coff_offset = (long)mz_header[2] * 512L;
+	  if (mz_header[1])
+	    coff_offset += (long)mz_header[1] - 512L;
+	  lseek (a_out, coff_offset, 0);
+	}
+      else
+	lseek (a_out, 0L, 0);
+#endif /* MSDOS */
+      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, coff_offset + 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.  */
+
+  f_hdr.f_flags |= (F_RELFLG | F_EXEC);
+  f_ohdr.text_start = (long) start_of_text ();
+  f_ohdr.tsize = data_start - f_ohdr.text_start;
+  f_ohdr.data_start = data_start;
+  f_ohdr.dsize = bss_start - f_ohdr.data_start;
+  f_ohdr.bsize = bss_end - bss_start;
+  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));
+  lnnoptr = f_thdr.s_lnnoptr;
+  text_scnptr = f_thdr.s_scnptr;
+  f_dhdr.s_paddr = f_ohdr.data_start;
+  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;
+  data_scnptr = f_dhdr.s_scnptr;
+  f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize;
+  f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize;
+  f_bhdr.s_size = f_ohdr.bsize;
+  f_bhdr.s_scnptr = 0L;
+  bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start;
+
+  if (f_hdr.f_symptr > 0L)
+    {
+      f_hdr.f_symptr += bias;
+    }
+
+  if (f_thdr.s_lnnoptr > 0L)
+    {
+      f_thdr.s_lnnoptr += bias;
+    }
+
+  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);
+    }
+
+  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);
+    }
+
+  return (0);
+
+}
+
+write_segment (new, ptr, end)
+     int new;
+     register char *ptr, *end;
+{
+  register int i, nwrite, ret;
+  char buf[80];
+  /* 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];
+
+  memset (zeros, 0, 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 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_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 MSDOS
+  /* 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
+
+  lseek (new, (long) text_scnptr, 0);
+  ptr = (char *) f_ohdr.text_start;
+  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
+  /* Restore our exception hooks.  */
+  __djgpp_exception_toggle ();
+
+  /* Restore the startup flags.  */
+  _crt0_startup_flags = save_djgpp_startup_flags;
+#endif
+
+
+  return 0;
+}
+
+/* ****************************************************************
+ * 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;
+
+  if (SYMS_START == 0L)
+    return 0;
+
+  if (lnnoptr)			/* if there is line number info */
+    lseek (a_out, coff_offset + lnnoptr, 0);	/* start copying from there */
+  else
+    lseek (a_out, coff_offset + 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);
+}
+
+
+/*
+ *	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;
+  struct syment symentry;
+  union auxent auxentry;
+
+  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;
+}
+
+extern unsigned start __asm__ ("start");
+
+/*
+ *	Return the address of the start of the text segment prior to
+ *	doing an unexec.  After unexec the return value is undefined.
+ *	See crt0.c for further explanation and _start.
+ *
+ */
+
+char *
+start_of_text (void)
+{
+  return ((char *) &start);
+}
+
+/* ****************************************************************
+ * 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
+      || adjust_lnnoptrs (new, a_out, new_name) < 0
+      )
+    {
+      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;
+}
+
+#endif /* not CANNOT_DUMP */
+
+/* arch-tag: 62409b69-e27a-4a7c-9413-0210d6b54e7f
+   (do not change this comment) */