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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#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 */