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freebsd/usr.bin/gprof/elf.c
David E. O'Brien 5e6220d9d0 * include/elf.h has been repo copied to include/elf-hints.h, and it no
longer includes machine/elf.h.
* consumers of elf.h now use the minimalist elf header possible.

This change is motivated by Binutils 2.11.0 and too much clashing over
our base elf headers and the Binutils elf headers.
2001-05-02 23:56:21 +00:00

111 lines
2.6 KiB
C

#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <machine/elf.h>
#include <err.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include "gprof.h"
static bool wantsym(const Elf_Sym *, const char *);
/* Things which get -E excluded by default. */
static char *excludes[] = { ".mcount", "_mcleanup", NULL };
int
elf_getnfile(const char *filename, char ***defaultEs)
{
int fd;
Elf_Ehdr h;
struct stat s;
void *mapbase;
const char *base;
const Elf_Shdr *shdrs;
const Elf_Shdr *sh_symtab;
const Elf_Shdr *sh_strtab;
const char *strtab;
const Elf_Sym *symtab;
int symtabct;
int i;
if ((fd = open(filename, O_RDONLY)) == -1)
err(1, "%s", filename);
if (read(fd, &h, sizeof h) != sizeof h || !IS_ELF(h)) {
close(fd);
return -1;
}
if (fstat(fd, &s) == -1)
err(1, "Cannot fstat %s", filename);
if ((mapbase = mmap(0, s.st_size, PROT_READ, MAP_SHARED, fd, 0)) ==
MAP_FAILED)
err(1, "Cannot mmap %s", filename);
close(fd);
base = (const char *)mapbase;
shdrs = (const Elf_Shdr *)(base + h.e_shoff);
/* Find the symbol table and associated string table section. */
for (i = 1; i < h.e_shnum; i++)
if (shdrs[i].sh_type == SHT_SYMTAB)
break;
if (i == h.e_shnum)
errx(1, "%s has no symbol table", filename);
sh_symtab = &shdrs[i];
sh_strtab = &shdrs[sh_symtab->sh_link];
symtab = (const Elf_Sym *)(base + sh_symtab->sh_offset);
symtabct = sh_symtab->sh_size / sh_symtab->sh_entsize;
strtab = (const char *)(base + sh_strtab->sh_offset);
/* Count the symbols that we're interested in. */
nname = 0;
for (i = 1; i < symtabct; i++)
if (wantsym(&symtab[i], strtab))
nname++;
/* Allocate memory for them, plus a terminating entry. */
if ((nl = (nltype *)calloc(nname + 1, sizeof(nltype))) == NULL)
errx(1, "Insufficient memory for symbol table");
/* Read them in. */
npe = nl;
for (i = 1; i < symtabct; i++) {
const Elf_Sym *sym = &symtab[i];
if (wantsym(sym, strtab)) {
npe->value = sym->st_value;
npe->name = strtab + sym->st_name;
npe++;
}
}
npe->value = -1;
*defaultEs = excludes;
return 0;
}
static bool
wantsym(const Elf_Sym *sym, const char *strtab)
{
int type;
int bind;
type = ELF_ST_TYPE(sym->st_info);
bind = ELF_ST_BIND(sym->st_info);
if (type != STT_FUNC ||
(aflag && bind == STB_LOCAL) ||
(uflag && strchr(strtab + sym->st_name, '.') != NULL))
return 0;
return 1;
}