cosmopolitan/libc/runtime/opensymboltable.c

64 lines
3.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program 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; version 2 of the License. │
│ │
│ This program 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 this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/alg/alg.h"
#include "libc/calls/calls.h"
#include "libc/elf/def.h"
#include "libc/elf/elf.h"
#include "libc/runtime/carsort.h"
#include "libc/runtime/internal.h"
#include "libc/runtime/runtime.h"
#include "libc/runtime/symbols.internal.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/prot.h"
/**
* Maps debuggable binary into memory and indexes symbol addresses.
*
* @return object freeable with CloseSymbolTable(), or NULL w/ errno
*/
struct SymbolTable *OpenSymbolTable(const char *filename) {
unsigned i, j;
struct SymbolTable *t;
const Elf64_Sym *symtab, *sym;
t = MAP_FAILED;
if (filename && (t = mapanon(BIGPAGESIZE)) != MAP_FAILED &&
MapElfRead(filename, &t->mf) &&
(t->name_base = GetElfStringTable(t->elf, t->elfsize)) != NULL &&
(symtab = GetElfSymbolTable(t->elf, t->elfsize, &t->count)) &&
sizeof(struct SymbolTable) + sizeof(struct Symbol) * t->count <
(t->scratch = BIGPAGESIZE)) {
GetElfVirtualAddressRange(t->elf, t->elfsize, &t->addr_base, &t->addr_end);
for (j = i = 0; i < t->count; ++i) {
sym = &symtab[i];
if (IsElfSymbolContent(sym) &&
(sym->st_value >= t->addr_base && sym->st_value <= t->addr_end)) {
t->symbols[j].addr_rva = (unsigned)(sym->st_value - t->addr_base);
t->symbols[j].name_rva = sym->st_name;
j++;
}
}
t->count = j;
carsort1000(t->count, (void *)t->symbols);
} else {
CloseSymbolTable(&t);
}
return t == MAP_FAILED ? NULL : t;
}