re PR lto/81968 (early lto debug objects make Solaris ld SEGV)

2018-01-11  Richard Biener  <rguenther@suse.de>
	Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>

	PR lto/81968
	libiberty/
	* simple-object-common.h (struct simple_object_functions):
	Change copy_lto_debug_sections callback signature.
	* simple-object-elf.c (SHN_HIRESERVE, SHT_SYMTAB_SHNDX,
	SHF_INFO_LINK): Add defines.
	(simple_object_elf_copy_lto_debug_sections): Instead of
	leaving not to be copied sections empty unnamed SHT_NULL
	remove them from the target section headers and adjust section
	reference everywhere.  Handle SHN_XINDEX in the symbol table
	processing properly.
	* simple-object.c (handle_lto_debug_sections): Change
	interface to return a modified string and handle renaming
	of relocation sections.

Co-Authored-By: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>

From-SVN: r256528
This commit is contained in:
Richard Biener 2018-01-11 12:12:39 +00:00 committed by Richard Biener
parent ec538483a1
commit bf6f2cc7be
4 changed files with 283 additions and 164 deletions

View File

@ -1,3 +1,20 @@
2018-01-11 Richard Biener <rguenther@suse.de>
Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
PR lto/81968
* simple-object-common.h (struct simple_object_functions):
Change copy_lto_debug_sections callback signature.
* simple-object-elf.c (SHN_HIRESERVE, SHT_SYMTAB_SHNDX,
SHF_INFO_LINK): Add defines.
(simple_object_elf_copy_lto_debug_sections): Instead of
leaving not to be copied sections empty unnamed SHT_NULL
remove them from the target section headers and adjust section
reference everywhere. Handle SHN_XINDEX in the symbol table
processing properly.
* simple-object.c (handle_lto_debug_sections): Change
interface to return a modified string and handle renaming
of relocation sections.
2018-01-10 Daniel van Gerpen <daniel@vangerpen.de>
* argv.c (expandargv): Correct check for dynamically

View File

@ -145,7 +145,7 @@ struct simple_object_functions
/* Copy LTO debug sections. */
const char *(*copy_lto_debug_sections) (simple_object_read *sobj,
simple_object_write *dobj,
int (*pfn) (const char **),
char *(*pfn) (const char *),
int *err);
};

View File

@ -126,6 +126,7 @@ typedef struct {
#define SHN_LORESERVE 0xFF00 /* Begin range of reserved indices */
#define SHN_COMMON 0xFFF2 /* Associated symbol is in common */
#define SHN_XINDEX 0xFFFF /* Section index is held elsewhere */
#define SHN_HIRESERVE 0xffff /* End of reserved indices */
/* 32-bit ELF program header. */
@ -193,9 +194,11 @@ typedef struct {
#define SHT_RELA 4 /* Relocation entries with addends */
#define SHT_REL 9 /* Relocation entries, no addends */
#define SHT_GROUP 17 /* Section contains a section group */
#define SHT_SYMTAB_SHNDX 18 /* Extended section indeces */
/* Values for sh_flags field. */
#define SHF_INFO_LINK 0x00000040 /* `sh_info' contains SHT index */
#define SHF_EXECINSTR 0x00000004 /* Executable section. */
#define SHF_EXCLUDE 0x80000000 /* Link editor is to exclude this
section from executable and
@ -1070,7 +1073,7 @@ simple_object_elf_release_write (void *data)
static const char *
simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
simple_object_write *dobj,
int (*pfn) (const char **),
char *(*pfn) (const char *),
int *err)
{
struct simple_object_elf_read *eor =
@ -1091,7 +1094,10 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
int changed;
int *pfnret;
const char **pfnname;
unsigned new_i;
unsigned *sh_map;
unsigned first_shndx = 0;
unsigned int *symtab_indices_shndx;
shdr_size = (ei_class == ELFCLASS32
? sizeof (Elf32_External_Shdr)
@ -1130,18 +1136,20 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
return errmsg;
}
eow->shdrs = XNEWVEC (unsigned char, shdr_size * (shnum - 1));
pfnret = XNEWVEC (int, shnum);
pfnname = XNEWVEC (const char *, shnum);
/* Map of symtab to index section. */
symtab_indices_shndx = XCNEWVEC (unsigned int, shnum - 1);
/* First perform the callbacks to know which sections to preserve and
what name to use for those. */
for (i = 1; i < shnum; ++i)
{
unsigned char *shdr;
unsigned int sh_name;
unsigned int sh_name, sh_type;
const char *name;
int ret;
char *ret;
shdr = shdrs + (i - 1) * shdr_size;
sh_name = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
@ -1156,12 +1164,28 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
name = (const char *) names + sh_name;
ret = (*pfn) (&name);
pfnret[i - 1] = ret == 1 ? 0 : -1;
pfnname[i - 1] = name;
ret = (*pfn) (name);
pfnret[i - 1] = ret == NULL ? -1 : 0;
pfnname[i - 1] = ret == NULL ? name : ret;
if (first_shndx == 0
&& pfnret[i - 1] == 0)
first_shndx = i;
/* Remember the indexes of existing SHT_SYMTAB_SHNDX sections. */
sh_type = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_type, Elf_Word);
if (sh_type == SHT_SYMTAB_SHNDX)
{
unsigned int sh_link;
sh_link = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word);
symtab_indices_shndx[sh_link - 1] = i;
/* Always discard the extended index sections, after
copying it will not be needed. This way we don't need to
update it and deal with the ordering constraints of
processing the existing symtab and changing the index. */
pfnret[i - 1] = -1;
}
}
/* Mark sections as preserved that are required by to be preserved
@ -1244,7 +1268,26 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
}
while (changed);
/* Compute a mapping of old -> new section numbers. */
sh_map = XNEWVEC (unsigned, shnum);
sh_map[0] = 0;
new_i = 1;
for (i = 1; i < shnum; ++i)
{
if (pfnret[i - 1] == -1)
sh_map[i] = 0;
else
sh_map[i] = new_i++;
}
if (new_i - 1 >= SHN_LORESERVE)
{
*err = ENOTSUP;
return "Too many copied sections";
}
eow->shdrs = XNEWVEC (unsigned char, shdr_size * (new_i - 1));
/* Then perform the actual copying. */
new_i = 0;
for (i = 1; i < shnum; ++i)
{
unsigned char *shdr;
@ -1252,11 +1295,14 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
const char *name;
off_t offset;
off_t length;
int ret;
simple_object_write_section *dest;
off_t flags;
unsigned char *buf;
if (pfnret[i - 1])
continue;
new_i++;
shdr = shdrs + (i - 1) * shdr_size;
sh_name = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_name, Elf_Word);
@ -1265,10 +1311,11 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
*err = 0;
XDELETEVEC (names);
XDELETEVEC (shdrs);
XDELETEVEC (symtab_indices_shndx);
return "ELF section name out of range";
}
name = (const char *) names + sh_name;
name = pfnname[i - 1];
offset = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_offset, Elf_Addr);
length = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
@ -1276,178 +1323,223 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
sh_type = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_type, Elf_Word);
ret = pfnret[i - 1];
name = ret == 0 ? pfnname[i - 1] : "";
dest = simple_object_write_create_section (dobj, name, 0, &errmsg, err);
dest = simple_object_write_create_section (dobj, pfnname[i - 1],
0, &errmsg, err);
if (dest == NULL)
{
XDELETEVEC (names);
XDELETEVEC (shdrs);
XDELETEVEC (symtab_indices_shndx);
return errmsg;
}
/* Record the SHDR of the source. */
memcpy (eow->shdrs + (i - 1) * shdr_size, shdr, shdr_size);
shdr = eow->shdrs + (i - 1) * shdr_size;
memcpy (eow->shdrs + (new_i - 1) * shdr_size, shdr, shdr_size);
shdr = eow->shdrs + (new_i - 1) * shdr_size;
/* Copy the data.
??? This is quite wasteful and ideally would be delayed until
write_to_file (). Thus it questions the interfacing
which eventually should contain destination creation plus
writing. */
/* Keep empty sections for sections we should discard. This avoids
the need to rewrite section indices in symtab and relocation
sections. */
if (ret == 0)
buf = XNEWVEC (unsigned char, length);
if (!simple_object_internal_read (sobj->descriptor,
sobj->offset + offset, buf,
(size_t) length, &errmsg, err))
{
buf = XNEWVEC (unsigned char, length);
if (!simple_object_internal_read (sobj->descriptor,
sobj->offset + offset, buf,
(size_t) length, &errmsg, err))
{
XDELETEVEC (buf);
XDELETEVEC (names);
XDELETEVEC (shdrs);
return errmsg;
}
XDELETEVEC (buf);
XDELETEVEC (names);
XDELETEVEC (shdrs);
XDELETEVEC (symtab_indices_shndx);
return errmsg;
}
/* If we are processing .symtab purge __gnu_lto_v1 and
__gnu_lto_slim symbols from it. */
if (sh_type == SHT_SYMTAB)
/* If we are processing .symtab purge __gnu_lto_v1 and
__gnu_lto_slim symbols from it and any symbols in discarded
sections. */
if (sh_type == SHT_SYMTAB)
{
unsigned entsize = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_entsize, Elf_Addr);
unsigned strtab = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word);
unsigned char *strshdr = shdrs + (strtab - 1) * shdr_size;
off_t stroff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
strshdr, sh_offset, Elf_Addr);
size_t strsz = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
strshdr, sh_size, Elf_Addr);
char *strings = XNEWVEC (char, strsz);
char *gnu_lto = strings;
unsigned char *ent;
unsigned *shndx_table = NULL;
simple_object_internal_read (sobj->descriptor,
sobj->offset + stroff,
(unsigned char *)strings,
strsz, &errmsg, err);
/* Find gnu_lto_ in strings. */
while ((gnu_lto = (char *) memchr (gnu_lto, 'g',
strings + strsz - gnu_lto)))
if (strncmp (gnu_lto, "gnu_lto_v1",
strings + strsz - gnu_lto) == 0)
break;
else
gnu_lto++;
/* Read the section index table if present. */
if (symtab_indices_shndx[i - 1] != 0)
{
unsigned entsize = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_entsize, Elf_Addr);
unsigned strtab = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word);
unsigned char *strshdr = shdrs + (strtab - 1) * shdr_size;
off_t stroff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
strshdr, sh_offset, Elf_Addr);
size_t strsz = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
strshdr, sh_size, Elf_Addr);
char *strings = XNEWVEC (char, strsz);
unsigned char *ent;
unsigned char *sidxhdr = shdrs + (strtab - 1) * shdr_size;
off_t sidxoff = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
sidxhdr, sh_offset, Elf_Addr);
size_t sidxsz = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
sidxhdr, sh_size, Elf_Addr);
shndx_table = (unsigned *)XNEWVEC (char, sidxsz);
simple_object_internal_read (sobj->descriptor,
sobj->offset + stroff,
(unsigned char *)strings,
strsz, &errmsg, err);
/* Find gnu_lto_ in strings. */
char *gnu_lto = strings;
while ((gnu_lto = memchr (gnu_lto, 'g',
strings + strsz - gnu_lto)))
if (strncmp (gnu_lto, "gnu_lto_v1",
strings + strsz - gnu_lto) == 0)
break;
else
gnu_lto++;
for (ent = buf; ent < buf + length; ent += entsize)
sobj->offset + sidxoff,
(unsigned char *)shndx_table,
sidxsz, &errmsg, err);
}
for (ent = buf; ent < buf + length; ent += entsize)
{
unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class,
Sym, ent,
st_shndx, Elf_Half);
unsigned raw_st_shndx = st_shndx;
unsigned char *st_info;
unsigned char *st_other;
int discard = 0;
if (ei_class == ELFCLASS32)
{
unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class,
Sym, ent,
st_shndx, Elf_Half);
unsigned char *st_info;
unsigned char *st_other;
int discard = 0;
if (ei_class == ELFCLASS32)
st_info = &((Elf32_External_Sym *)ent)->st_info;
st_other = &((Elf32_External_Sym *)ent)->st_other;
}
else
{
st_info = &((Elf64_External_Sym *)ent)->st_info;
st_other = &((Elf64_External_Sym *)ent)->st_other;
}
if (st_shndx == SHN_XINDEX)
st_shndx = type_functions->fetch_Elf_Word
((unsigned char *)(shndx_table + (ent - buf) / entsize));
/* Eliminate all COMMONs - this includes __gnu_lto_v1
and __gnu_lto_slim which otherwise cause endless
LTO plugin invocation. */
if (st_shndx == SHN_COMMON)
discard = 1;
/* We also need to remove symbols refering to sections
we'll eventually remove as with fat LTO objects
we otherwise get duplicate symbols at final link
(with GNU ld, gold is fine and ignores symbols in
sections marked as EXCLUDE). ld/20513 */
else if (st_shndx != SHN_UNDEF
&& st_shndx < shnum
&& pfnret[st_shndx - 1] == -1)
discard = 1;
if (discard)
{
/* Make discarded symbols undefined and unnamed
in case it is local. */
int bind = ELF_ST_BIND (*st_info);
int other = STV_DEFAULT;
if (bind == STB_LOCAL)
{
st_info = &((Elf32_External_Sym *)ent)->st_info;
st_other = &((Elf32_External_Sym *)ent)->st_other;
/* Make discarded local symbols unnamed and
defined in the first prevailing section. */
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_name, Elf_Word, 0);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_shndx, Elf_Half,
sh_map[first_shndx]);
}
else
{
st_info = &((Elf64_External_Sym *)ent)->st_info;
st_other = &((Elf64_External_Sym *)ent)->st_other;
}
/* Eliminate all COMMONs - this includes __gnu_lto_v1
and __gnu_lto_slim which otherwise cause endless
LTO plugin invocation. */
if (st_shndx == SHN_COMMON)
discard = 1;
/* We also need to remove symbols refering to sections
we'll eventually remove as with fat LTO objects
we otherwise get duplicate symbols at final link
(with GNU ld, gold is fine and ignores symbols in
sections marked as EXCLUDE). ld/20513 */
else if (st_shndx != SHN_UNDEF
&& st_shndx < shnum
&& pfnret[st_shndx - 1] == -1)
discard = 1;
if (discard)
{
/* Make discarded symbols undefined and unnamed
in case it is local. */
int bind = ELF_ST_BIND (*st_info);
int other = STV_DEFAULT;
if (bind == STB_LOCAL)
{
/* Make discarded local symbols unnamed and
defined in the first prevailing section. */
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_name, Elf_Word, 0);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_shndx, Elf_Half, first_shndx);
}
else
{
/* Make discarded global symbols hidden weak
undefined and sharing the gnu_lto_ name. */
bind = STB_WEAK;
other = STV_HIDDEN;
if (gnu_lto)
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_name, Elf_Word,
gnu_lto - strings);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_shndx, Elf_Half, SHN_UNDEF);
}
*st_other = other;
*st_info = ELF_ST_INFO (bind, STT_NOTYPE);
/* Make discarded global symbols hidden weak
undefined and sharing the gnu_lto_ name. */
bind = STB_WEAK;
other = STV_HIDDEN;
if (gnu_lto)
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_name, Elf_Word,
gnu_lto - strings);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_value, Elf_Addr, 0);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_size, Elf_Word, 0);
ent, st_shndx, Elf_Half, SHN_UNDEF);
}
*st_other = other;
*st_info = ELF_ST_INFO (bind, STT_NOTYPE);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_value, Elf_Addr, 0);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_size, Elf_Word, 0);
}
XDELETEVEC (strings);
}
errmsg = simple_object_write_add_data (dobj, dest,
buf, length, 1, err);
XDELETEVEC (buf);
if (errmsg)
{
XDELETEVEC (names);
XDELETEVEC (shdrs);
return errmsg;
else if (raw_st_shndx < SHN_LORESERVE
|| raw_st_shndx == SHN_XINDEX)
/* Remap the section reference. */
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_shndx, Elf_Half, sh_map[st_shndx]);
}
XDELETEVEC (strings);
XDELETEVEC (shndx_table);
}
else
else if (sh_type == SHT_GROUP)
{
/* For deleted sections mark the section header table entry as
unused. That allows the link editor to remove it in a partial
link. */
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_type, Elf_Word, SHT_NULL);
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_info, Elf_Word, 0);
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word, 0);
/* Remap section indices in groups and remove removed members. */
unsigned char *ent, *dst;
for (dst = ent = buf + 4; ent < buf + length; ent += 4)
{
unsigned shndx = type_functions->fetch_Elf_Word (ent);
if (pfnret[shndx - 1] == -1)
;
else
{
type_functions->set_Elf_Word (dst, sh_map[shndx]);
dst += 4;
}
}
/* Adjust the length. */
length = dst - buf;
}
errmsg = simple_object_write_add_data (dobj, dest,
buf, length, 1, err);
XDELETEVEC (buf);
if (errmsg)
{
XDELETEVEC (names);
XDELETEVEC (shdrs);
XDELETEVEC (symtab_indices_shndx);
return errmsg;
}
flags = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_flags, Elf_Addr);
if (ret == 0)
{
/* The debugobj doesn't contain any code, thus no trampolines.
Even when the original object needs trampolines, debugobj
doesn't. */
if (strcmp (name, ".note.GNU-stack") == 0)
flags &= ~SHF_EXECINSTR;
flags &= ~SHF_EXCLUDE;
}
else if (ret == -1)
flags = SHF_EXCLUDE;
/* Remap the section references. */
{
unsigned int sh_info, sh_link;
if (flags & SHF_INFO_LINK || sh_type == SHT_REL || sh_type == SHT_RELA)
{
sh_info = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_info, Elf_Word);
if (sh_info < SHN_LORESERVE
|| sh_info > SHN_HIRESERVE)
sh_info = sh_map[sh_info];
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_info, Elf_Word, sh_info);
}
sh_link = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word);
if (sh_link < SHN_LORESERVE
|| sh_link > SHN_HIRESERVE)
sh_link = sh_map[sh_link];
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word, sh_link);
}
/* The debugobj doesn't contain any code, thus no trampolines.
Even when the original object needs trampolines, debugobj
doesn't. */
if (strcmp (name, ".note.GNU-stack") == 0)
flags &= ~SHF_EXECINSTR;
/* Clear SHF_EXCLUDE on to be preserved sections. */
flags &= ~SHF_EXCLUDE;
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_flags, Elf_Addr, flags);
}
@ -1456,6 +1548,8 @@ simple_object_elf_copy_lto_debug_sections (simple_object_read *sobj,
XDELETEVEC (shdrs);
XDELETEVEC (pfnret);
XDELETEVEC (pfnname);
XDELETEVEC (symtab_indices_shndx);
XDELETEVEC (sh_map);
return NULL;
}

View File

@ -253,30 +253,38 @@ simple_object_find_section (simple_object_read *sobj, const char *name,
/* Callback to identify and rename LTO debug sections by name.
Returns 1 if NAME is a LTO debug section, 0 if not. */
static int
handle_lto_debug_sections (const char **name)
static char *
handle_lto_debug_sections (const char *name)
{
char *newname = XCNEWVEC (char, strlen (name) + 1);
/* ??? So we can't use .gnu.lto_ prefixed sections as the assembler
complains about bogus section flags. Which means we need to arrange
for that to be fixed or .gnu.debuglto_ marked as SHF_EXCLUDE (to make
fat lto object tooling work for the fat part). */
/* Also include corresponding reloc sections. */
if (strncmp (name, ".rela", sizeof (".rela") - 1) == 0)
{
strncpy (newname, name, sizeof (".rela") - 1);
name += sizeof (".rela") - 1;
}
else if (strncmp (name, ".rel", sizeof (".rel") - 1) == 0)
{
strncpy (newname, name, sizeof (".rel") - 1);
name += sizeof (".rel") - 1;
}
/* ??? For now this handles both .gnu.lto_ and .gnu.debuglto_ prefixed
sections. */
/* Copy LTO debug sections and rename them to their non-LTO name. */
if (strncmp (*name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0)
{
*name = *name + sizeof (".gnu.debuglto_") - 1;
return 1;
}
else if (strncmp (*name, ".gnu.lto_.debug_", sizeof (".gnu.lto_.debug_") -1) == 0)
{
*name = *name + sizeof (".gnu.lto_") - 1;
return 1;
}
if (strncmp (name, ".gnu.debuglto_", sizeof (".gnu.debuglto_") - 1) == 0)
return strcat (newname, name + sizeof (".gnu.debuglto_") - 1);
else if (strncmp (name, ".gnu.lto_.debug_",
sizeof (".gnu.lto_.debug_") -1) == 0)
return strcat (newname, name + sizeof (".gnu.lto_") - 1);
/* Copy over .note.GNU-stack section under the same name if present. */
else if (strcmp (*name, ".note.GNU-stack") == 0)
return 1;
return 0;
else if (strcmp (name, ".note.GNU-stack") == 0)
return strcpy (newname, name);
return NULL;
}
/* Copy LTO debug sections. */