/* simple-object-elf.c -- routines to manipulate ELF object files.
- Copyright (C) 2010-2019 Free Software Foundation, Inc.
+ Copyright (C) 2010-2023 Free Software Foundation, Inc.
Written by Ian Lance Taylor, Google.
This program is free software; you can redistribute it and/or modify it
not handle objects with more than SHN_LORESERVE sections
correctly. All large section indexes were offset by
0x100. There is more information at
- http://sourceware.org/bugzilla/show_bug.cgi?id-5900 .
+ https://sourceware.org/PR5900 .
Fortunately these object files are easy to detect, as the
GNU binutils always put the section header string table
near the end of the list of sections. Thus if the
XDELETE (eor);
return NULL;
}
-
+
+ if (eor->shstrndx == 0)
+ {
+ *errmsg = "invalid ELF shstrndx == 0";
+ *err = 0;
+ XDELETE (eor);
+ return NULL;
+ }
+
return (void *) eor;
}
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;
+ symtab_indices_shndx[sh_link - 1] = i - 1;
/* 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
return errmsg;
}
- /* If we are processing .symtab purge __gnu_lto_v1 and
- __gnu_lto_slim symbols from it and any symbols in discarded
- sections. */
+ /* If we are processing .symtab purge 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;
+ size_t prevailing_name_idx = 0;
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 char *sidxhdr = shdrs + (strtab - 1) * shdr_size;
+ unsigned char *sidxhdr = shdrs + symtab_indices_shndx[i - 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);
+ unsigned int shndx_type
+ = ELF_FETCH_FIELD (type_functions, ei_class, Shdr,
+ sidxhdr, sh_type, Elf_Word);
+ if (shndx_type != SHT_SYMTAB_SHNDX)
+ return "Wrong section type of a SYMTAB SECTION INDICES section";
shndx_table = (unsigned *)XNEWVEC (char, sidxsz);
simple_object_internal_read (sobj->descriptor,
sobj->offset + sidxoff,
(unsigned char *)shndx_table,
sidxsz, &errmsg, err);
}
+
+ /* Find a WEAK HIDDEN symbol which name we will use for removed
+ symbols. We know there's a prevailing weak hidden symbol
+ at the start of the .debug_info section. */
+ 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 char *st_info;
+ unsigned char *st_other;
+ 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));
+
+ if (st_shndx != SHN_COMMON
+ && !(st_shndx != SHN_UNDEF
+ && st_shndx < shnum
+ && pfnret[st_shndx - 1] == -1)
+ && ELF_ST_BIND (*st_info) == STB_WEAK
+ && *st_other == STV_HIDDEN)
+ {
+ prevailing_name_idx = ELF_FETCH_FIELD (type_functions,
+ ei_class, Sym, ent,
+ st_name, Elf_Word);
+ break;
+ }
+ }
+
for (ent = buf; ent < buf + length; ent += entsize)
{
unsigned st_shndx = ELF_FETCH_FIELD (type_functions, ei_class,
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. */
+ /* Eliminate all COMMONs - this includes __gnu_lto_slim
+ which otherwise cause endless LTO plugin invocation.
+ FIXME: remove the condition once we remove emission
+ of __gnu_lto_slim symbol. */
if (st_shndx == SHN_COMMON)
discard = 1;
/* We also need to remove symbols refering to sections
&& st_shndx < shnum
&& pfnret[st_shndx - 1] == -1)
discard = 1;
+ /* We also need to remove global UNDEFs which can
+ cause link fails later. */
+ else if (st_shndx == SHN_UNDEF
+ && ELF_ST_BIND (*st_info) == STB_GLOBAL)
+ discard = 1;
if (discard)
{
else
{
/* Make discarded global symbols hidden weak
- undefined and sharing the gnu_lto_ name. */
+ undefined and sharing a name of a prevailing
+ symbol. */
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_name, Elf_Word,
+ prevailing_name_idx);
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_shndx, Elf_Half, SHN_UNDEF);
}
ELF_SET_FIELD (type_functions, ei_class, Sym,
ent, st_shndx, Elf_Half, sh_map[st_shndx]);
}
- XDELETEVEC (strings);
XDELETEVEC (shndx_table);
}
else if (sh_type == SHT_GROUP)
{
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];
+ 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];
+ sh_link = sh_map[sh_link];
ELF_SET_FIELD (type_functions, ei_class, Shdr,
shdr, sh_link, Elf_Word, sh_link);
}
projects / thirdparty / gcc.git / blobdiff