/* Add symbols from a plugin-claimed input file. */
static enum ld_plugin_status
add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms)
{
asymbol **symptrs;
bfd *abfd = handle;
int n;
ASSERT (called_plugin);
symptrs = xmalloc (nsyms * sizeof *symptrs);
for (n = 0; n < nsyms; n++)
{
enum ld_plugin_status rv;
asymbol *bfdsym = bfd_make_empty_symbol (abfd);
symptrs[n] = bfdsym;
rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n);
if (rv != LDPS_OK)
return rv;
}
bfd_set_symtab (abfd, symptrs, nsyms);
return LDPS_OK;
}
static void emit_so_bfd(const Chunk *base, uint64_t textOffs, uint64_t textLen,
std::vector<MethBlock> &blocks,
std::vector<DebugInfo> &debugInfos)
{
bfd_init();
bfd *abfd = bfd_openw("jit.o",
#ifdef __MACH__
"mach-o-i386"
#else
"elf32-i386"
#endif
) ;
bfd_set_format(abfd, bfd_object);
#ifdef __MACH__
bfd_set_arch_mach(abfd, bfd_arch_i386, bfd_mach_i386_i386);
#else
bfd_set_arch_mach(abfd, bfd_arch_i386, bfd_mach_i386_i386);
#endif
asection *textSection = bfd_make_section(abfd, ".text");
bfd_set_section_flags(
abfd, textSection,
SEC_ALLOC | SEC_LOAD | SEC_READONLY | SEC_CODE | SEC_HAS_CONTENTS);
#ifdef __MACH__
bfd_set_section_size(abfd, textSection, textLen);
// for mach-o, the .o we generate is linked into a .dylib
// so just set the alignment to make sure things end up
// in the right place after link
textSection->alignment_power = l2(textOffs);
static const uint64_t textAdj = 0;
#else
bfd_set_section_size(abfd, textSection, textLen + textOffs);
// for linux (and oprofile) the generated object is used
// directly, so just offset the symbols
uint64_t textAdj = textOffs;
#endif
asymbol **symbols = (asymbol **) malloc(
sizeof(asymbol *) * (6 + blocks.size()));
uint64_t start = ((uint64_t *) base->data)[0] + textOffs;
int n = 0;
std::map<std::string, int> namesSeen;
std::vector<MethBlock>::const_iterator i, e;
symbols[n++] = make_glob_symbol(abfd, "__jitStart", textSection, textAdj);
symbols[n++] = make_glob_symbol(abfd, "_jitStart", textSection, textAdj);
for (i = blocks.begin(), e = blocks.end(); i != e; i++, n++) {
std::string name = i->name();
int seen = namesSeen[name]++;
if (seen) {
char buf[16];
sprintf(buf, " (%d)", seen);
name += buf;
}
symbols[n] = make_glob_symbol(abfd, name.c_str(), textSection,
i->start() - start + textAdj);
}
symbols[n++] = make_glob_symbol(abfd, "__jitUnused", textSection,
blocks.back().end() - start + textAdj);
symbols[n++] = make_glob_symbol(abfd, "_jitUnused", textSection,
blocks.back().end() - start + textAdj);
symbols[n++] = make_glob_symbol(abfd, "__jitEnd", textSection,
textLen + textAdj);
symbols[n++] = make_glob_symbol(abfd, "_jitEnd", textSection,
textLen + textAdj);
bfd_set_symtab(abfd, symbols, n);
for (i = blocks.begin(), e = blocks.end(); i != e; i++, n++)
if (i->codeBytes())
bfd_set_section_contents(abfd, textSection, i->codeBytes(),
i->start() - start, i->codeLen());
bfd_close(abfd);
for (int n = 0; n < blocks.size(); n++)
free((void *) symbols[n]->name);
free(symbols);
}
main (int argc, char **argv) {
bfd *ibfd, *obfd;
asection *p;
static asymbol **osympp, **delsympp;
long symsize, symcount, delsymcount;
int i;
int c;
int idx;
struct add_reloc_struct *new_reloc;
struct change_reloc_struct *new_change;
struct delete_reloc_struct *new_delete;
struct modify_byte_struct *new_modify;
struct globalize_sym_struct *new_globalize;
while ((c = getopt (argc, argv, "a:d:c:m:G:")) != -1) {
switch (c) {
case 'a':
/* check to see if we have two args: name and loc */
if ((index(optarg, ',') == NULL) ||
(index(optarg, ',') != rindex(optarg, ','))) {
fprintf(stderr, "usage: -a argument should be <symbolname>,<location>, not \"%s\"\n", optarg);
exit(1);
}
/* record the add reloc command in the global array */
new_reloc = (add_reloc_struct *)malloc(sizeof(add_reloc_struct));
new_reloc->symbol_name = strndup(optarg, (index(optarg, ',') - optarg));
new_reloc->loc = strtol(index(optarg, ',') + 1, NULL, 0);
if (errno == EINVAL) {
fprintf(stderr, "the value %s is not a valid location for the add command\n", index(optarg, ',') + 1);
exit(1);
}
new_reloc->next = additional_relocs;
additional_relocs = new_reloc;
break;
case 'c':
/* check to see if we have two args */
if ((index(optarg, ',') == NULL) ||
(index(optarg, ',') != rindex(optarg, ','))) {
fprintf(stderr, "usage: -c argument should be <symbolname>,<symbolname>, not \"%s\"\n", optarg);
exit(1);
}
new_change = (change_reloc_struct *)malloc(sizeof(change_reloc_struct));
new_change->old_symbol_name = strndup(optarg, strlen(optarg) - strlen(index(optarg, ',')));
new_change->new_symbol_name = strdup(index(optarg, ',') + 1);
new_change->next = change_relocs;
change_relocs = new_change;
break;
case 'd':
new_delete = (delete_reloc_struct *)malloc(sizeof(delete_reloc_struct));
new_delete->symbol_name = strdup(optarg);
new_delete->next = delete_relocs;
delete_relocs = new_delete;
break;
case 'm':
if ((index(optarg, '=') == NULL) ||
(index(optarg, '=') != rindex(optarg, '='))) {
fprintf(stderr, "usage: -m argument should be <location>=<value>, not \"%s\"\n", optarg);
exit(1);
}
new_modify = (modify_byte_struct *)malloc(sizeof(modify_byte_struct));
new_modify->location = strtol(optarg, NULL, 0);
new_modify->value = strtol(index(optarg, '=') + 1, NULL, 0);
if (new_modify->value > 0xff) {
fprintf(stderr, "requested modify value %lx for location %lx exceeds 0xff\n",
new_modify->value, new_modify->location);
exit(1);
}
new_modify->next = modify_bytes;
modify_bytes = new_modify;
break;
case 'G':
new_globalize = (globalize_sym_struct *)malloc(sizeof(globalize_sym_struct));
new_globalize->symbol_name = strdup(optarg);
new_globalize->next = globalize_syms;
globalize_syms = new_globalize;
break;
default:
fprintf(stderr, "unrecognized argument character |%c|\n", c);
}
}
if ((argc - optind) != 2) {
fprintf(stderr, "usage: fixup_relocs [-a newsymbol,location] [-c oldsymbol,newsymbol] [-d symbol] infile.o outfile.o\n");
exit(1);
}
ibfd = bfd_openr(argv[optind], NULL);
if (ibfd == NULL) {
bfd_perror("while opening input object file");
exit(1);
}
/* if I don't do "check_format", there's no data in the bfd object. wtf? */
if (!bfd_check_format(ibfd, bfd_object)) {
fprintf(stderr, "input file %s seems to NOT be an object file! exiting.\n", argv[optind]);
exit(1);
}
obfd = bfd_openw(argv[optind+1], bfd_get_target(ibfd));
if (obfd == NULL) {
bfd_perror("while opening output object file");
exit(1);
}
if (!bfd_set_format(obfd, bfd_get_format(ibfd))) {
bfd_perror("while setting output object file format");
}
/* copy a bunch of necessary global stuff */
bfd_set_start_address(obfd, bfd_get_start_address(ibfd));
bfd_set_file_flags(obfd, bfd_get_file_flags(ibfd));
bfd_set_arch_mach(obfd, bfd_get_arch(ibfd), bfd_get_mach(ibfd));
/* BOZO objcopy sets format again at this point. why? */
bfd_map_over_sections (ibfd, setup_section, obfd);
setup_bfd_headers (ibfd, obfd);
/* Symbol filtering must happen after the output sections
have been created, but before their contents are set. */
symsize = bfd_get_symtab_upper_bound (ibfd);
if (symsize < 0) {
fprintf(stderr, "problem processing %s\n", bfd_get_filename (ibfd));
return FALSE;
}
/* count the added relocations so we can put extra space in the output symbol table for them */
int reloc_add_cnt, reloc_delete_cnt;
reloc_add_cnt = 0;
reloc_delete_cnt = 0;
for (new_reloc = additional_relocs; new_reloc != NULL; new_reloc = new_reloc->next) {
reloc_add_cnt++;
}
/* the "change" symbols might also not be in the symbol table yet */
for (new_change = change_relocs; new_change != NULL; new_change = new_change->next) {
reloc_add_cnt++;
/* the old symbol may be deleted, also */
reloc_delete_cnt++;
}
for (new_delete = delete_relocs; new_delete != NULL; new_delete = new_delete->next) {
reloc_delete_cnt++;
}
/* filter symbol table in two steps: */
/* 1) move symbols bound for deletion to the end of the output symbol table array */
/* 2) truncate the table at the first of those */
/* this makes it possible to do the reloc processing with the symbol table intact, */
/* and remove the deleted symbols afterwards, without corrupting the reloc data structures */
isympp = malloc (symsize);
osympp = malloc (symsize + reloc_add_cnt * sizeof(asymbol *));
delsympp = malloc (reloc_delete_cnt * sizeof(asymbol *));
symcount = bfd_canonicalize_symtab (ibfd, isympp);
if (symcount < 0) {
fprintf(stderr, "problem processing %s\n", bfd_get_filename (ibfd));
return FALSE;
}
/* remove any undefined symbols whose relocation entries were deleted or changed */
int osym_idx, delsym_idx;
osym_idx = delsym_idx = 0;
delsymcount = 0;
for (i = 0; i < symcount; i++) {
if ((is_delete_reloc(bfd_asymbol_name(isympp[i]), delete_relocs) ||
(find_change_reloc(bfd_asymbol_name(isympp[i]), change_relocs) != NULL)) &&
(isympp[i]->section != NULL) &&
(strcmp(isympp[i]->section->name, BFD_UND_SECTION_NAME) == 0)) {
delsympp[delsym_idx++] = isympp[i];
}
else {
if (is_globalize_sym(bfd_asymbol_name(isympp[i]), globalize_syms)) {
isympp[i]->flags = BSF_GLOBAL;
}
osympp[osym_idx++] = isympp[i];
}
}
symcount = osym_idx;
delsymcount = delsym_idx;
osympp[symcount] = NULL;
/* add the symbols for additional relocs to the table */
int added_symbol_cnt = 0;
for (new_reloc = additional_relocs; new_reloc != NULL; new_reloc = new_reloc->next) {
if (find_symbol(osympp, new_reloc->symbol_name) < 0) {
/* not yet present, so add it */
asymbol *new_sym;
new_sym = bfd_make_empty_symbol(obfd);
new_sym->name = strdup(new_reloc->symbol_name);
new_sym->section = bfd_get_section_by_name (obfd, ".text");
new_sym->value = new_reloc->loc;
new_sym->flags = BSF_GLOBAL;
osympp[symcount + added_symbol_cnt++] = new_sym;
osympp[symcount + added_symbol_cnt] = NULL;
}
}
/* do the same for changed relocs */
for (new_change = change_relocs; new_change != NULL; new_change = new_change->next) {
if (find_symbol(osympp, new_change->new_symbol_name) < 0) {
/* not yet present, so add it */
/* since this is a name change, we will reuse the existing address (value field of reloc) */
int old_symbol_idx;
if ((old_symbol_idx = find_symbol(isympp, new_change->old_symbol_name)) < 0) {
fprintf(stderr, "change command old symbol name %s not found in symbol table! Exiting.\n", new_change->old_symbol_name);
exit(1);
}
asymbol *new_sym;
new_sym = bfd_make_empty_symbol(obfd);
new_sym->name = strdup(new_change->new_symbol_name);
new_sym->section = bfd_und_section_ptr;
new_sym->value = isympp[old_symbol_idx]->value;
new_sym->flags = BSF_GLOBAL;
fprintf(stderr, "adding new symbol %s for change reloc command\n", new_sym->name);
osympp[symcount + added_symbol_cnt++] = new_sym;
osympp[symcount + added_symbol_cnt] = NULL;
}
}
/* append the soon-to-be deleted symbols to the end of the output symbol table */
for (i = 0; i < delsymcount; i++) {
osympp[symcount + added_symbol_cnt + i] = delsympp[i];
}
osympp[symcount + added_symbol_cnt + delsymcount] = NULL;
bfd_set_symtab (obfd, osympp, symcount + added_symbol_cnt + delsymcount);
/* This has to happen after the symbol table has been set. */
bfd_map_over_sections (ibfd, copy_section_relocs_edit, obfd);
/* now truncate the symbol table to eliminate the deleted symbols */
osympp[symcount + added_symbol_cnt] = NULL;
bfd_set_symtab (obfd, osympp, symcount + added_symbol_cnt);
/* now that we've set the relocs and cleaned the symtab, can call this */
bfd_map_over_sections (ibfd, copy_section_data, obfd);
bfd_close(obfd);
bfd_close(ibfd);
return 0;
}
