RetroZilla/tools/leaky/elf.cpp
2015-10-20 23:03:22 -04:00

166 lines
4.9 KiB
C++

/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is
* Kipp E.B. Hickman.
* Portions created by the Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "leaky.h"
#ifdef USE_ELF
#include "leaky.h"
#include <stdio.h>
#include <malloc.h>
#include <libelf/libelf.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
void leaky::readSymbols(const char *fileName)
{
int fd = ::open(fileName, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "%s: unable to open \"%s\"\n", applicationName,
fileName);
exit(-1);
}
elf_version(EV_CURRENT);
Elf *elf = elf_begin(fd, ELF_C_READ, 0);
if (!elf) {
fprintf(stderr, "%s: \"%s\": has no symbol table\n", applicationName,
fileName);
exit(-1);
}
long alloced = 10000;
Symbol* syms = (Symbol*) malloc(sizeof(Symbol) * 10000);
Symbol* sp = syms;
Symbol* last = syms + alloced;
// Get each of the relevant sections and add them to the list of
// symbols.
Elf32_Ehdr *ehdr = elf32_getehdr(elf);
if (!ehdr) {
fprintf(stderr, "%s: elf library lossage\n", applicationName);
exit(-1);
}
#if 0
Elf32_Half ndx = ehdr->e_shstrndx;
#endif
Elf_Scn *scn = 0;
int strtabndx = -1;
for (int i = 1; (scn = elf_nextscn(elf, scn)) != 0; i++) {
Elf32_Shdr *shdr = elf32_getshdr(scn);
#if 0
char *name = elf_strptr(elf, ndx, (size_t) shdr->sh_name);
printf("Section %s (%d 0x%x)\n", name ? name : "(null)",
shdr->sh_type, shdr->sh_type);
#endif
if (shdr->sh_type == SHT_STRTAB) {
/* We assume here that string tables preceed symbol tables... */
strtabndx = i;
continue;
}
#if 0
if (shdr->sh_type == SHT_DYNAMIC) {
/* Dynamic */
Elf_Data *data = elf_getdata(scn, 0);
if (!data || !data->d_size) {
printf("No data...");
continue;
}
Elf32_Dyn *dyn = (Elf32_Dyn*) data->d_buf;
Elf32_Dyn *lastdyn =
(Elf32_Dyn*) ((char*) data->d_buf + data->d_size);
for (; dyn < lastdyn; dyn++) {
printf("tag=%d value=0x%x\n", dyn->d_tag, dyn->d_un.d_val);
}
} else
#endif
if ((shdr->sh_type == SHT_SYMTAB) ||
(shdr->sh_type == SHT_DYNSYM)) {
/* Symbol table */
Elf_Data *data = elf_getdata(scn, 0);
if (!data || !data->d_size) {
printf("No data...");
continue;
}
/* In theory we now have the symbols... */
Elf32_Sym *esym = (Elf32_Sym*) data->d_buf;
Elf32_Sym *lastsym =
(Elf32_Sym*) ((char*) data->d_buf + data->d_size);
for (; esym < lastsym; esym++) {
#if 0
char *nm = elf_strptr(elf, strtabndx, (size_t)esym->st_name);
printf("%20s 0x%08x %02x %02x\n",
nm, esym->st_value, ELF32_ST_BIND(esym->st_info),
ELF32_ST_TYPE(esym->st_info));
#endif
if ((esym->st_value == 0) ||
(ELF32_ST_BIND(esym->st_info) == STB_WEAK) ||
(ELF32_ST_BIND(esym->st_info) == STB_NUM) ||
(ELF32_ST_TYPE(esym->st_info) != STT_FUNC)) {
continue;
}
#if 1
char *nm = elf_strptr(elf, strtabndx, (size_t)esym->st_name);
#endif
sp->name = nm ? strdup(nm) : "(no name)";
sp->address = esym->st_value;
sp++;
if (sp >= last) {
long n = alloced + 10000;
syms = (Symbol*)
realloc(syms, (size_t) (sizeof(Symbol) * n));
last = syms + n;
sp = syms + alloced;
alloced = n;
}
}
}
}
int interesting = sp - syms;
if (!quiet) {
printf("Total of %d symbols\n", interesting);
}
usefulSymbols = interesting;
externalSymbols = syms;
}
#endif /* USE_ELF */