symbol.c

debug source code under unix platform.

    n /= sizeof(struct nlist);
    /* Look for the string table.
     */
    m = e + N_STROFF(*o);
    if (b < 4)
        i = 0;
    else
        i = *((size_t *) m);
    if ((i == 0) || (b < i))
    {
        c = "missing string table";
        if (l != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", l, f, c);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, c);
        return 1;
    }
    if (l != NULL)
        f = l;
    /* Cycle through every symbol contained in the executable file.
     */
    for (i = 0; i < n; i++, p++)
        /* We only need to bother looking at text symbols.
         */
        if ((((p->n_type & N_TYPE) == N_TEXT) && !(p->n_type & N_STAB)) &&
            !addsymbol(y, p, f, m + p->n_un.n_strx, a))
            return 0;
    return 1;
}
#elif FORMAT == FORMAT_COFF || FORMAT == FORMAT_XCOFF
/* Allocate a set of symbol nodes for a COFF or XCOFF executable file.
 */

static
int
addsymbols(symhead *y, char *e, char *l, char *f, size_t b, size_t a)
{
    char n[SYMNMLEN + 1];
    FILHDR *o;
    AOUTHDR *v;
    SCNHDR *h;
    SYMENT *p;
    char *c, *m, *s;
    size_t i, t;

    /* Check that we have a valid COFF or XCOFF executable file.
     */
    if (b < FILHSZ)
    {
        c = "not an object file";
        if (l != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", l, f, c);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, c);
        return 1;
    }
    o = (FILHDR *) e;
    b -= FILHSZ;
    if (!ISCOFF(o->f_magic) || (o->f_opthdr == 0) || (b < o->f_opthdr))
    {
        c = "not an executable file";
        if (l != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", l, f, c);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, c);
        return 1;
    }
    /* COFF and XCOFF dynamic linkers don't record the original start
     * address of the text section so we must adjust the base address here
     * if necessary.
     */
    if ((a != 0) && (o->f_opthdr >= sizeof(AOUTHDR)))
    {
        v = (AOUTHDR *) (e + FILHSZ);
        if (a > v->text_start)
            a -= (v->text_start & ~0xFFFF);
    }
    b -= o->f_opthdr;
    if ((o->f_nscns == 0) || (b < o->f_nscns * SCNHSZ))
    {
        c = "missing section table";
        if (l != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", l, f, c);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, c);
        return 1;
    }
    /* Look for the section index of the text section.  This is
     * usually 1, but we should really make sure.
     */
    h = (SCNHDR *) (e + FILHSZ + o->f_opthdr);
    b += FILHSZ + o->f_opthdr - o->f_symptr;
    for (i = t = 0; i < o->f_nscns; i++)
        if ((h[i].s_flags & STYP_TEXT) ||
            (strncmp(h[i].s_name, ".text", 8) == 0))
        {
            t = i + 1;
            break;
        }
    if (t == 0)
        t = 1;
    /* Look for the symbol table.
     */
    i = o->f_nsyms * SYMESZ;
    if ((o->f_symptr == 0) || (o->f_nsyms == 0) || (b < i))
    {
        c = "missing symbol table";
        if (l != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", l, f, c);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, c);
        return 1;
    }
    p = (SYMENT *) (e + o->f_symptr);
    b -= i;
    /* Look for the string table.
     */
    m = (char *) p + i;
    if (b < 4)
        i = 0;
    else
        i = *((size_t *) m);
    if ((i == 0) || (b < i))
    {
        c = "missing string table";
        if (l != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", l, f, c);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, c);
        return 1;
    }
    if (l != NULL)
        f = l;
    /* Cycle through every symbol contained in the executable file.
     */
    for (i = 0; i < o->f_nsyms; i += p->n_numaux + 1,
         p = (SYMENT *) ((char *) p + (p->n_numaux + 1) * SYMESZ))
        /* We only need to bother looking at text symbols.
         */
        if (p->n_scnum == t)
        {
            if (p->n_zeroes)
            {
                /* Symbol name is stored in structure.
                 */
                strncpy(n, p->n_name, SYMNMLEN);
                n[SYMNMLEN] = '\0';
                s = n;
            }
            else
                /* Symbol name is stored in string table.
                 */
                s = m + p->n_offset;
            if (!addsymbol(y, p, f, s, a))
                return 0;
        }
    return 1;
}
#elif FORMAT == FORMAT_ELF32
/* Allocate a set of symbol nodes for an ELF32 object file.
 */

static
int
addsymbols(symhead *y, Elf *e, char *a, char *f, size_t b)
{
    Elf_Scn *s;
    Elf32_Shdr *h;
    Elf32_Sym *p;
    Elf_Data *d;
    char *m;
    size_t i, l, n, t;

    /* Look for the symbol table.
     */
    for (s = elf_nextscn(e, NULL), d = NULL; s != NULL; s = elf_nextscn(e, s))
        if ((h = elf32_getshdr(s)) && (h->sh_type == SHT_SYMTAB) &&
            (d = elf_getdata(s, NULL)))
            break;
    if (d == NULL)
        /* If we couldn't find the symbol table then it is likely that the file
         * has been stripped.  However, if the file was dynamically linked then
         * we may be able to obtain some symbols from its dynamic symbol table.
         */
        for (s = elf_nextscn(e, NULL), d = NULL; s != NULL;
             s = elf_nextscn(e, s))
            if ((h = elf32_getshdr(s)) && (h->sh_type == SHT_DYNSYM) &&
                (d = elf_getdata(s, NULL)))
                break;
    if ((d == NULL) || (d->d_buf == NULL) || (d->d_size == 0))
    {
        m = "missing symbol table";
        if (a != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        return 1;
    }
    t = h->sh_link;
    /* Look for the string table.
     */
    if (((s = elf_getscn(e, t)) == NULL) || ((h = elf32_getshdr(s)) == NULL) ||
        (h->sh_type != SHT_STRTAB))
    {
        m = "missing string table";
        if (a != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        return 1;
    }
    if (a != NULL)
        f = a;
    p = (Elf32_Sym *) d->d_buf + 1;
    l = d->d_size / sizeof(Elf32_Sym);
    /* Cycle through every symbol contained in the object file.
     */
    for (i = 1; i < l; i++, p++)
        /* We don't need to bother looking at undefined, absolute or common
         * symbols, and we only need to store non-data symbols.  However, on
         * IRIX the section index for a symbol in a linked object file does
         * not always refer to the ELF section it was defined in so we skip
         * the last check.
         */
#if SYSTEM == SYSTEM_IRIX
        if (((n = p->st_shndx) != SHN_UNDEF) && (n != SHN_ABS) &&
            (n != SHN_COMMON))
#else /* SYSTEM */
        if (((n = p->st_shndx) != SHN_UNDEF) && (n != SHN_ABS) &&
            (n != SHN_COMMON) && (s = elf_getscn(e, n)) &&
            (h = elf32_getshdr(s)) && (h->sh_flags & SHF_EXECINSTR))
#endif /* SYSTEM */
            if (!addsymbol(y, p, f, elf_strptr(e, t, p->st_name), b))
                return 0;
    return 1;
}
#elif FORMAT == FORMAT_ELF64
/* Allocate a set of symbol nodes for an ELF64 object file.
 */

static
int
addsymbols(symhead *y, Elf *e, char *a, char *f, size_t b)
{
    Elf_Scn *s;
    Elf64_Shdr *h;
    Elf64_Sym *p;
    Elf_Data *d;
    char *m;
    size_t i, l, n, t;

    /* Look for the symbol table.
     */
    for (s = elf_nextscn(e, NULL), d = NULL; s != NULL; s = elf_nextscn(e, s))
        if ((h = elf64_getshdr(s)) && (h->sh_type == SHT_SYMTAB) &&
            (d = elf_getdata(s, NULL)))
            break;
    if (d == NULL)
        /* If we couldn't find the symbol table then it is likely that the file
         * has been stripped.  However, if the file was dynamically linked then
         * we may be able to obtain some symbols from its dynamic symbol table.
         */
        for (s = elf_nextscn(e, NULL), d = NULL; s != NULL;
             s = elf_nextscn(e, s))
            if ((h = elf64_getshdr(s)) && (h->sh_type == SHT_DYNSYM) &&
                (d = elf_getdata(s, NULL)))
                break;
    if ((d == NULL) || (d->d_buf == NULL) || (d->d_size == 0))
    {
        m = "missing symbol table";
        if (a != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        return 1;
    }
    t = h->sh_link;
    /* Look for the string table.
     */
    if (((s = elf_getscn(e, t)) == NULL) || ((h = elf64_getshdr(s)) == NULL) ||
        (h->sh_type != SHT_STRTAB))
    {
        m = "missing string table";
        if (a != NULL)
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        return 1;
    }
    if (a != NULL)
        f = a;
    p = (Elf64_Sym *) d->d_buf + 1;
    l = d->d_size / sizeof(Elf64_Sym);
    /* Cycle through every symbol contained in the object file.
     */
    for (i = 1; i < l; i++, p++)
        /* We don't need to bother looking at undefined, absolute or common
         * symbols, and we only need to store non-data symbols.  However, on
         * IRIX the section index for a symbol in a linked object file does
         * not always refer to the ELF section it was defined in so we skip
         * the last check.
         */
#if SYSTEM == SYSTEM_IRIX
        if (((n = p->st_shndx) != SHN_UNDEF) && (n != SHN_ABS) &&
            (n != SHN_COMMON))
#else /* SYSTEM */
        if (((n = p->st_shndx) != SHN_UNDEF) && (n != SHN_ABS) &&
            (n != SHN_COMMON) && (s = elf_getscn(e, n)) &&
            (h = elf64_getshdr(s)) && (h->sh_flags & SHF_EXECINSTR))
#endif /* SYSTEM */
            if (!addsymbol(y, p, f, elf_strptr(e, t, p->st_name), b))
                return 0;
    return 1;
}
#elif FORMAT == FORMAT_BFD
/* Allocate a set of symbol nodes for a BFD object file.
 */

static
int
addsymbols(symhead *y, bfd *h, char *a, char *f, size_t b)
{
    asymbol **p;
    char *m;
    long i, n;
    int d, r;

    /* Look for the symbol table.
     */
    d = 0;
    if ((n = bfd_get_symtab_upper_bound(h)) < 0)
    {
        m = (char *) bfd_errmsg(bfd_get_error());
        if (a != NULL)
            __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        return 0;
    }
    if (n == 0)
    {
        /* If we couldn't find the symbol table then it is likely that the file
         * has been stripped.  However, if the file was dynamically linked then
         * we may be able to obtain some symbols from its dynamic symbol table.
         */
        if ((n = bfd_get_dynamic_symtab_upper_bound(h)) < 0)
        {
            m = (char *) bfd_errmsg(bfd_get_error());
            if (a != NULL)
                __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
            else
                __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
            return 0;
        }
        if (n == 0)
        {
            m = "missing symbol table";
            if (a != NULL)
                __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
            else
                __mp_warn(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
            return 1;
        }
        d = 1;
    }
    /* It's actually safe to call malloc() here since the library checks
     * for recursive behaviour.
     */
    if ((p = (asymbol **) malloc(n)) == NULL)
    {
        m = "no memory for symbols";
        if (a != NULL)
            __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        return 0;
    }
    r = 1;
    if (((d == 0) && ((n = bfd_canonicalize_symtab(h, p)) < 0)) ||
        ((d == 1) && ((n = bfd_canonicalize_dynamic_symtab(h, p)) < 0)))
    {
        m = (char *) bfd_errmsg(bfd_get_error());
        if (a != NULL)
            __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s [%s]: %s\n", a, f, m);
        else
            __mp_error(ET_MAX, AT_MAX, NULL, 0, "%s: %s\n", f, m);
        r = 0;
    }
    else
    {
        /* Cycle through every symbol contained in the object file.
         */
        if (a != NULL)
            f = a;
        for (i = 0; i < n; i++)
            /* We don't need to bother looking at undefined, absolute or common
             * symbols, and we only need to store non-data symbols.
             */
            if (!bfd_is_und_section(p[i]->section) &&
                !bfd_is_abs_section(p[i]->section) &&
                !bfd_is_com_section(p[i]->section) &&
                (p[i]->section->flags & SEC_CODE))
                if (!addsymbol(y, p[i], f, (char *) p[i]->name,
                    (size_t) p[i]->section->vma + b))
                {
                    r = 0;
                    break;
                }
    }
    /* If we are making use of line number information in the object files then