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merge from gcc

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DJ Delorie 2011-10-26 15:56:36 +00:00
parent 5110b5dfaa
commit 85d7ed08a8
2 changed files with 453 additions and 85 deletions
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13
libiberty/ChangeLog
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@ -1,3 +1,16 @@
2011-10-26 Iain Sandoe <iains@gcc.gnu.org>
PR target/48108
* simple-object-mach-o.c (GNU_WRAPPER_SECTS, GNU_WRAPPER_INDEX,
GNU_WRAPPER_NAMES): New macros.
(simple_object_mach_o_segment): Handle wrapper scheme.
(simple_object_mach_o_write_section_header): Allow the segment name
to be supplied.
(simple_object_mach_o_write_segment): Handle wrapper scheme. Ensure
that the top-level segment name in the load command is empty.
(simple_object_mach_o_write_to_file): Determine the number of
sections during segment output, use that in writing the header.
2011-10-10 Ian Lance Taylor <iant@google.com>
PR c++/48665

525
libiberty/simple-object-mach-o.c
View File

@ -1,5 +1,5 @@
/* simple-object-mach-o.c -- routines to manipulate Mach-O object files.
Copyright 2010 Free Software Foundation, Inc.
Copyright 2010, 2011 Free Software Foundation, Inc.
Written by Ian Lance Taylor, Google.
This program is free software; you can redistribute it and/or modify it
@ -174,6 +174,15 @@ struct mach_o_section_64
#define GNU_SECTION_NAMES "__section_names"
/* A GNU-specific extension to wrap multiple sections using three
mach-o sections within a given segment. The section '__wrapper_sects'
is subdivided according to the index '__wrapper_index' and each sub
sect is named according to the names supplied in '__wrapper_names'. */
#define GNU_WRAPPER_SECTS "__wrapper_sects"
#define GNU_WRAPPER_INDEX "__wrapper_index"
#define GNU_WRAPPER_NAMES "__wrapper_names"
/* Private data for an simple_object_read. */
struct simple_object_mach_o_read
@ -214,7 +223,18 @@ struct simple_object_mach_o_attributes
unsigned int reserved;
};
/* See if we have a Mach-O file. */
/* See if we have a Mach-O MH_OBJECT file:
A standard MH_OBJECT (from as) will have three load commands:
0 - LC_SEGMENT/LC_SEGMENT64
1 - LC_SYMTAB
2 - LC_DYSYMTAB
The LC_SEGMENT/LC_SEGMENT64 will introduce a single anonymous segment
containing all the sections.
Files written by simple-object will have only the segment command
(no symbol tables). */
static void *
simple_object_mach_o_match (
@ -356,8 +376,29 @@ simple_object_mach_o_section_info (int is_big_endian, int is_32,
}
}
/* Handle a segment in a Mach-O file. Return 1 if we should continue,
0 if the caller should return. */
/* Handle a segment in a Mach-O Object file.
This will callback to the function pfn for each "section found" the meaning
of which depends on gnu extensions to mach-o:
If we find mach-o sections (with the segment name as specified) which also
contain: a 'sects' wrapper, an index, and a name table, we expand this into
as many sections as are specified in the index. In this case, there will
be a callback for each of these.
We will also allow an extension that permits long names (more than 16
characters) to be used with mach-o. In this case, the section name has
a specific format embedding an index into a name table, and the file must
contain such name table.
Return 1 if we should continue, 0 if the caller should return. */
#define SOMO_SECTS_PRESENT 0x01
#define SOMO_INDEX_PRESENT 0x02
#define SOMO_NAMES_PRESENT 0x04
#define SOMO_LONGN_PRESENT 0x08
#define SOMO_WRAPPING (SOMO_SECTS_PRESENT | SOMO_INDEX_PRESENT \
| SOMO_NAMES_PRESENT)
static int
simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
@ -378,9 +419,20 @@ simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
unsigned int nsects;
unsigned char *secdata;
unsigned int i;
unsigned int gnu_sections_found;
unsigned int strtab_index;
unsigned int index_index;
unsigned int nametab_index;
unsigned int sections_index;
char *strtab;
char *nametab;
unsigned char *index;
size_t strtab_size;
size_t nametab_size;
size_t index_size;
unsigned int n_wrapped_sects;
size_t wrapper_sect_size;
off_t wrapper_sect_offset;
fetch_32 = (omr->is_big_endian
? simple_object_fetch_big_32
@ -409,6 +461,8 @@ simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
nsects));
}
/* Fetch the section headers from the segment command. */
secdata = XNEWVEC (unsigned char, nsects * sechdrsize);
if (!simple_object_internal_read (sobj->descriptor, offset + seghdrsize,
secdata, nsects * sechdrsize, errmsg, err))
@ -417,9 +471,13 @@ simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
return 0;
}
/* Scan for a __section_names section. This is in effect a GNU
extension that permits section names longer than 16 chars. */
/* Scan for special sections that signal GNU extensions to the format. */
gnu_sections_found = 0;
index_index = nsects;
sections_index = nsects;
strtab_index = nsects;
nametab_index = nsects;
for (i = 0; i < nsects; ++i)
{
size_t nameoff;
@ -427,18 +485,103 @@ simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
nameoff = i * sechdrsize + segname_offset;
if (strcmp ((char *) secdata + nameoff, omr->segment_name) != 0)
continue;
nameoff = i * sechdrsize + sectname_offset;
if (strcmp ((char *) secdata + nameoff, GNU_SECTION_NAMES) == 0)
break;
if (strcmp ((char *) secdata + nameoff, GNU_WRAPPER_NAMES) == 0)
{
nametab_index = i;
gnu_sections_found |= SOMO_NAMES_PRESENT;
}
else if (strcmp ((char *) secdata + nameoff, GNU_WRAPPER_INDEX) == 0)
{
index_index = i;
gnu_sections_found |= SOMO_INDEX_PRESENT;
}
else if (strcmp ((char *) secdata + nameoff, GNU_WRAPPER_SECTS) == 0)
{
sections_index = i;
gnu_sections_found |= SOMO_SECTS_PRESENT;
}
else if (strcmp ((char *) secdata + nameoff, GNU_SECTION_NAMES) == 0)
{
strtab_index = i;
gnu_sections_found |= SOMO_LONGN_PRESENT;
}
}
strtab_index = i;
if (strtab_index >= nsects)
/* If any of the special wrapper section components is present, then
they all should be. */
if ((gnu_sections_found & SOMO_WRAPPING) != 0)
{
strtab = NULL;
strtab_size = 0;
off_t nametab_offset;
off_t index_offset;
if ((gnu_sections_found & SOMO_WRAPPING) != SOMO_WRAPPING)
{
*errmsg = "GNU Mach-o section wrapper: required section missing";
*err = 0; /* No useful errno. */
XDELETEVEC (secdata);
return 0;
}
/* Fetch the name table. */
simple_object_mach_o_section_info (omr->is_big_endian, is_32,
secdata + nametab_index * sechdrsize,
&nametab_offset, &nametab_size);
nametab = XNEWVEC (char, nametab_size);
if (!simple_object_internal_read (sobj->descriptor,
sobj->offset + nametab_offset,
(unsigned char *) nametab, nametab_size,
errmsg, err))
{
XDELETEVEC (nametab);
XDELETEVEC (secdata);
return 0;
}
/* Fetch the index. */
simple_object_mach_o_section_info (omr->is_big_endian, is_32,
secdata + index_index * sechdrsize,
&index_offset, &index_size);
index = XNEWVEC (unsigned char, index_size);
if (!simple_object_internal_read (sobj->descriptor,
sobj->offset + index_offset,
index, index_size,
errmsg, err))
{
XDELETEVEC (index);
XDELETEVEC (nametab);
XDELETEVEC (secdata);
return 0;
}
/* The index contains 4 unsigned ints per sub-section:
sub-section offset/length, sub-section name/length.
We fix this for both 32 and 64 bit mach-o for now, since
other fields limit the maximum size of an object to 4G. */
n_wrapped_sects = index_size / 16;
/* Get the parameters for the wrapper too. */
simple_object_mach_o_section_info (omr->is_big_endian, is_32,
secdata + sections_index * sechdrsize,
&wrapper_sect_offset,
&wrapper_sect_size);
}
else
{
index = NULL;
index_size = 0;
nametab = NULL;
nametab_size = 0;
n_wrapped_sects = 0;
}
/* If we have a long names section, fetch it. */
if ((gnu_sections_found & SOMO_LONGN_PRESENT) != 0)
{
off_t strtab_offset;
@ -452,52 +595,120 @@ simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
errmsg, err))
{
XDELETEVEC (strtab);
XDELETEVEC (index);
XDELETEVEC (nametab);
XDELETEVEC (secdata);
return 0;
}
}
else
{
strtab = NULL;
strtab_size = 0;
strtab_index = nsects;
}
/* Process the sections. */
for (i = 0; i < nsects; ++i)
{
const unsigned char *sechdr;
char namebuf[MACH_O_NAME_LEN + 1];
char namebuf[MACH_O_NAME_LEN * 2 + 2];
char *name;
off_t secoffset;
size_t secsize;
if (i == strtab_index)
continue;
int l;
sechdr = secdata + i * sechdrsize;
/* We've already processed the long section names. */
if ((gnu_sections_found & SOMO_LONGN_PRESENT) != 0
&& i == strtab_index)
continue;
/* We only act on the segment named. */
if (strcmp ((char *) sechdr + segname_offset, omr->segment_name) != 0)
continue;
memcpy (namebuf, sechdr + sectname_offset, MACH_O_NAME_LEN);
namebuf[MACH_O_NAME_LEN] = '\0';
/* Process sections associated with the wrapper. */
name = &namebuf[0];
if (strtab != NULL && name[0] == '_' && name[1] == '_')
if ((gnu_sections_found & SOMO_WRAPPING) != 0)
{
unsigned long stringoffset;
if (i == nametab_index || i == index_index)
continue;
if (sscanf (name + 2, "%08lX", &stringoffset) == 1)
if (i == sections_index)
{
if (stringoffset >= strtab_size)
unsigned int j;
for (j = 0; j < n_wrapped_sects; ++j)
{
*errmsg = "section name offset out of range";
*err = 0;
XDELETEVEC (strtab);
XDELETEVEC (secdata);
return 0;
}
unsigned int subsect_offset, subsect_length, name_offset;
subsect_offset = (*fetch_32) (index + 16 * j);
subsect_length = (*fetch_32) (index + 16 * j + 4);
name_offset = (*fetch_32) (index + 16 * j + 8);
/* We don't need the name_length yet. */
name = strtab + stringoffset;
secoffset = wrapper_sect_offset + subsect_offset;
secsize = subsect_length;
name = nametab + name_offset;
if (!(*pfn) (data, name, secoffset, secsize))
{
*errmsg = NULL;
*err = 0;
XDELETEVEC (index);
XDELETEVEC (nametab);
XDELETEVEC (strtab);
XDELETEVEC (secdata);
return 0;
}
}
continue;
}
}
if ((gnu_sections_found & SOMO_LONGN_PRESENT) != 0)
{
memcpy (namebuf, sechdr + sectname_offset, MACH_O_NAME_LEN);
namebuf[MACH_O_NAME_LEN] = '\0';
name = &namebuf[0];
if (strtab != NULL && name[0] == '_' && name[1] == '_')
{
unsigned long stringoffset;
if (sscanf (name + 2, "%08lX", &stringoffset) == 1)
{
if (stringoffset >= strtab_size)
{
*errmsg = "section name offset out of range";
*err = 0;
XDELETEVEC (index);
XDELETEVEC (nametab);
XDELETEVEC (strtab);
XDELETEVEC (secdata);
return 0;
}
name = strtab + stringoffset;
}
}
}
else
{
/* Otherwise, make a name like __segment,__section as per the
convention in mach-o asm. */
name = &namebuf[0];
memset (namebuf, 0, MACH_O_NAME_LEN * 2 + 2);
memcpy (namebuf, (char *) sechdr + segname_offset, MACH_O_NAME_LEN);
l = strlen (namebuf);
namebuf[l] = ',';
memcpy (namebuf + l + 1, (char *) sechdr + sectname_offset,
MACH_O_NAME_LEN);
}
simple_object_mach_o_section_info (omr->is_big_endian, is_32, sechdr,
&secoffset, &secsize);
@ -505,12 +716,16 @@ simple_object_mach_o_segment (simple_object_read *sobj, off_t offset,
{
*errmsg = NULL;
*err = 0;
XDELETEVEC (index);
XDELETEVEC (nametab);
XDELETEVEC (strtab);
XDELETEVEC (secdata);
return 0;
}
}
XDELETEVEC (index);
XDELETEVEC (nametab);
XDELETEVEC (strtab);
XDELETEVEC (secdata);
@ -724,9 +939,9 @@ static int
simple_object_mach_o_write_section_header (simple_object_write *sobj,
int descriptor,
size_t sechdr_offset,
const char *name, size_t secaddr,
size_t secsize, size_t offset,
unsigned int align,
const char *name, const char *segn,
size_t secaddr, size_t secsize,
size_t offset, unsigned int align,
const char **errmsg, int *err)
{
struct simple_object_mach_o_attributes *attrs =
@ -748,7 +963,7 @@ simple_object_mach_o_write_section_header (simple_object_write *sobj,
strncpy ((char *) hdr + offsetof (struct mach_o_section_32, sectname),
name, MACH_O_NAME_LEN);
strncpy ((char *) hdr + offsetof (struct mach_o_section_32, segname),
sobj->segment_name, MACH_O_NAME_LEN);
segn, MACH_O_NAME_LEN);
set_32 (hdr + offsetof (struct mach_o_section_32, addr), secaddr);
set_32 (hdr + offsetof (struct mach_o_section_32, size), secsize);
set_32 (hdr + offsetof (struct mach_o_section_32, offset), offset);
@ -773,7 +988,7 @@ simple_object_mach_o_write_section_header (simple_object_write *sobj,
strncpy ((char *) hdr + offsetof (struct mach_o_section_64, sectname),
name, MACH_O_NAME_LEN);
strncpy ((char *) hdr + offsetof (struct mach_o_section_64, segname),
sobj->segment_name, MACH_O_NAME_LEN);
segn, MACH_O_NAME_LEN);
set_64 (hdr + offsetof (struct mach_o_section_64, addr), secaddr);
set_64 (hdr + offsetof (struct mach_o_section_64, size), secsize);
set_32 (hdr + offsetof (struct mach_o_section_64, offset), offset);
@ -793,11 +1008,25 @@ simple_object_mach_o_write_section_header (simple_object_write *sobj,
sechdrsize, errmsg, err);
}
/* Write out the single segment and the sections of a Mach-O file. */
/* Write out the single (anonymous) segment containing the sections of a Mach-O
Object file.
As a GNU extension to mach-o, when the caller specifies a segment name in
sobj->segment_name, all the sections passed will be output under a single
mach-o section header. The caller's sections are indexed within this
'wrapper' section by a table stored in a second mach-o section. Finally,
arbitrary length section names are permitted by the extension and these are
stored in a table in a third mach-o section.
Note that this is only likely to make any sense for the __GNU_LTO segment
at present.
If the wrapper extension is not in force, we assume that the section name
is in the form __SEGMENT_NAME,__section_name as per Mach-O asm. */
static int
simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
size_t nsects, const char **errmsg,
size_t *nsects, const char **errmsg,
int *err)
{
struct simple_object_mach_o_attributes *attrs =
@ -814,6 +1043,10 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
simple_object_write_section *section;
unsigned char hdrbuf[sizeof (struct mach_o_segment_command_64)];
unsigned char *hdr;
size_t nsects_in;
unsigned int *index;
char *snames;
unsigned int sect;
set_32 = (attrs->is_big_endian
? simple_object_set_big_32
@ -834,19 +1067,62 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
sechdrsize = sizeof (struct mach_o_section_64);
}
sechdr_offset = hdrsize + seghdrsize;
cmdsize = seghdrsize + nsects * sechdrsize;
offset = hdrsize + cmdsize;
name_offset = 0;
secaddr = 0;
*nsects = nsects_in = 0;
/* Count the number of sections we start with. */
for (section = sobj->sections; section != NULL; section = section->next)
nsects_in++;
if (sobj->segment_name != NULL)
{
/* We will only write 3 sections: wrapped data, index and names. */
*nsects = 3;
/* The index has four entries per wrapped section:
Section Offset, length, Name offset, length.
Where the offsets are based at the start of the wrapper and name
sections respectively.
The values are stored as 32 bit int for both 32 and 64 bit mach-o
since the size of a mach-o MH_OBJECT cannot exceed 4G owing to
other constraints. */
index = XNEWVEC (unsigned int, nsects_in * 4);
/* We now need to figure out the size of the names section. This just
stores the names as null-terminated c strings, packed without any
alignment padding. */
for (section = sobj->sections, sect = 0; section != NULL;
section = section->next, sect++)
{
index[sect*4+2] = name_offset;
index[sect*4+3] = strlen (section->name) + 1;
name_offset += strlen (section->name) + 1;
}
snames = XNEWVEC (char, name_offset);
}
else
{
*nsects = nsects_in;
index = NULL;
snames = NULL;
}
sechdr_offset = hdrsize + seghdrsize;
cmdsize = seghdrsize + *nsects * sechdrsize;
offset = hdrsize + cmdsize;
secaddr = 0;
for (section = sobj->sections, sect = 0;
section != NULL; section = section->next, sect++)
{
size_t mask;
size_t new_offset;
size_t secsize;
struct simple_object_write_section_buffer *buffer;
char namebuf[MACH_O_NAME_LEN + 1];
mask = (1U << section->align) - 1;
new_offset = offset + mask;
@ -877,39 +1153,126 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
secsize += buffer->size;
}
snprintf (namebuf, sizeof namebuf, "__%08X", name_offset);
if (!simple_object_mach_o_write_section_header (sobj, descriptor,
sechdr_offset, namebuf,
secaddr, secsize, offset,
section->align,
errmsg, err))
return 0;
if (sobj->segment_name != NULL)
{
index[sect*4+0] = (unsigned int) offset;
index[sect*4+1] = secsize;
/* Stash the section name in our table. */
memcpy (snames + index[sect * 4 + 2], section->name,
index[sect * 4 + 3]);
}
else
{
char namebuf[MACH_O_NAME_LEN + 1];
char segnbuf[MACH_O_NAME_LEN + 1];
char *comma;
/* Try to extract segment,section from the input name. */
memset (namebuf, 0, sizeof namebuf);
memset (segnbuf, 0, sizeof segnbuf);
comma = strchr (section->name, ',');
if (comma != NULL)
{
int len = comma - section->name;
len = len > MACH_O_NAME_LEN ? MACH_O_NAME_LEN : len;
strncpy (namebuf, section->name, len);
strncpy (segnbuf, comma + 1, MACH_O_NAME_LEN);
}
else /* just try to copy the name, leave segment blank. */
strncpy (namebuf, section->name, MACH_O_NAME_LEN);
if (!simple_object_mach_o_write_section_header (sobj, descriptor,
sechdr_offset,
namebuf, segnbuf,
secaddr, secsize,
offset,
section->align,
errmsg, err))
return 0;
sechdr_offset += sechdrsize;
}
sechdr_offset += sechdrsize;
offset += secsize;
name_offset += strlen (section->name) + 1;
secaddr += secsize;
}
/* Write out the section names. */
if (!simple_object_mach_o_write_section_header (sobj, descriptor,
sechdr_offset,
GNU_SECTION_NAMES, secaddr,
name_offset, offset, 0,
errmsg, err))
return 0;
for (section = sobj->sections; section != NULL; section = section->next)
if (sobj->segment_name != NULL)
{
size_t namelen;
size_t secsize;
unsigned int i;
namelen = strlen (section->name) + 1;
if (!simple_object_internal_write (descriptor, offset,
(const unsigned char *) section->name,
namelen, errmsg, err))
/* Write the section header for the wrapper. */
/* Account for any initial aligment - which becomes the alignment for this
created section. */
secsize = (offset - index[0]);
if (!simple_object_mach_o_write_section_header (sobj, descriptor,
sechdr_offset,
GNU_WRAPPER_SECTS,
sobj->segment_name,
0 /*secaddr*/,
secsize, index[0],
sobj->sections->align,
errmsg, err))
return 0;
offset += namelen;
/* Subtract the wrapper section start from the begining of each sub
section. */
for (i = 1; i < nsects_in; ++i)
index[4 * i] -= index[0];
index[0] = 0;
sechdr_offset += sechdrsize;
/* Write out the section names.
... the header ...
name_offset contains the length of the section. It is not aligned. */
if (!simple_object_mach_o_write_section_header (sobj, descriptor,
sechdr_offset,
GNU_WRAPPER_NAMES,
sobj->segment_name,
0 /*secaddr*/,
name_offset,
offset,
0, errmsg, err))
return 0;
/* ... and the content.. */
if (!simple_object_internal_write (descriptor, offset,
(const unsigned char *) snames,
name_offset, errmsg, err))
return 0;
sechdr_offset += sechdrsize;
secaddr += name_offset;
offset += name_offset;
/* Now do the index, we'll align this to 4 bytes although the read code
will handle unaligned. */
offset += 3;
offset &= ~0x03;
if (!simple_object_mach_o_write_section_header (sobj, descriptor,
sechdr_offset,
GNU_WRAPPER_INDEX,
sobj->segment_name,
0 /*secaddr*/,
nsects_in * 16,
offset,
2, errmsg, err))
return 0;
/* ... and the content.. */
if (!simple_object_internal_write (descriptor, offset,
(const unsigned char *) index,
nsects_in*16, errmsg, err))
return 0;
XDELETEVEC (index);
XDELETEVEC (snames);
}
/* Write out the segment header. */
@ -923,9 +1286,8 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
MACH_O_LC_SEGMENT);
set_32 (hdr + offsetof (struct mach_o_segment_command_32, cmdsize),
cmdsize);
strncpy (((char *) hdr
+ offsetof (struct mach_o_segment_command_32, segname)),
sobj->segment_name, MACH_O_NAME_LEN);
/* MH_OBJECTS have a single, anonymous, segment - so the segment name
is left empty. */
/* vmaddr left as zero. */
/* vmsize left as zero. */
set_32 (hdr + offsetof (struct mach_o_segment_command_32, fileoff),
@ -935,7 +1297,7 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
/* maxprot left as zero. */
/* initprot left as zero. */
set_32 (hdr + offsetof (struct mach_o_segment_command_32, nsects),
nsects);
*nsects);
/* flags left as zero. */
}
else
@ -951,9 +1313,8 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
MACH_O_LC_SEGMENT);
set_32 (hdr + offsetof (struct mach_o_segment_command_64, cmdsize),
cmdsize);
strncpy (((char *) hdr
+ offsetof (struct mach_o_segment_command_64, segname)),
sobj->segment_name, MACH_O_NAME_LEN);
/* MH_OBJECTS have a single, anonymous, segment - so the segment name
is left empty. */
/* vmaddr left as zero. */
/* vmsize left as zero. */
set_64 (hdr + offsetof (struct mach_o_segment_command_64, fileoff),
@ -963,7 +1324,7 @@ simple_object_mach_o_write_segment (simple_object_write *sobj, int descriptor,
/* maxprot left as zero. */
/* initprot left as zero. */
set_32 (hdr + offsetof (struct mach_o_segment_command_64, nsects),
nsects);
*nsects);
/* flags left as zero. */
#endif
}
@ -978,23 +1339,17 @@ static const char *
simple_object_mach_o_write_to_file (simple_object_write *sobj, int descriptor,
int *err)
{
size_t nsects;
simple_object_write_section *section;
size_t nsects = 0;
const char *errmsg;
/* Start at 1 for symbol_names section. */
nsects = 1;
for (section = sobj->sections; section != NULL; section = section->next)
++nsects;
if (!simple_object_mach_o_write_segment (sobj, descriptor, &nsects,
&errmsg, err))
return errmsg;
if (!simple_object_mach_o_write_header (sobj, descriptor, nsects,
&errmsg, err))
return errmsg;
if (!simple_object_mach_o_write_segment (sobj, descriptor, nsects,
&errmsg, err))
return errmsg;
return NULL;
}