@@ -66,18 +66,8 @@ gdb_mpz::read (gdb::array_view<const gdb_byte> buf, enum bfd_endian byte_order,
/* See gmp-utils.h. */
void
-gdb_mpz::write (gdb::array_view<gdb_byte> buf, enum bfd_endian byte_order,
- bool unsigned_p) const
-{
- this->safe_export
- (buf, byte_order == BFD_ENDIAN_BIG ? 1 : -1 /* endian */, unsigned_p);
-}
-
-/* See gmp-utils.h. */
-
-void
-gdb_mpz::safe_export (gdb::array_view<gdb_byte> buf,
- int endian, bool unsigned_p) const
+gdb_mpz::export_bits (gdb::array_view<gdb_byte> buf, int endian, bool unsigned_p,
+ bool safe) const
{
gdb_assert (buf.size () > 0);
@@ -92,36 +82,39 @@ gdb_mpz::safe_export (gdb::array_view<gdb_byte> buf,
return;
}
- /* Determine the maximum range of values that our buffer can hold,
- and verify that VAL is within that range. */
-
- gdb_mpz lo, hi;
- const size_t max_usable_bits = buf.size () * HOST_CHAR_BIT;
- if (unsigned_p)
- {
- lo = 0;
-
- mpz_ui_pow_ui (hi.m_val, 2, max_usable_bits);
- mpz_sub_ui (hi.m_val, hi.m_val, 1);
- }
- else
+ if (safe)
{
- mpz_ui_pow_ui (lo.m_val, 2, max_usable_bits - 1);
- mpz_neg (lo.m_val, lo.m_val);
-
- mpz_ui_pow_ui (hi.m_val, 2, max_usable_bits - 1);
- mpz_sub_ui (hi.m_val, hi.m_val, 1);
+ /* Determine the maximum range of values that our buffer can
+ hold, and verify that VAL is within that range. */
+
+ gdb_mpz lo, hi;
+ const size_t max_usable_bits = buf.size () * HOST_CHAR_BIT;
+ if (unsigned_p)
+ {
+ lo = 0;
+
+ mpz_ui_pow_ui (hi.m_val, 2, max_usable_bits);
+ mpz_sub_ui (hi.m_val, hi.m_val, 1);
+ }
+ else
+ {
+ mpz_ui_pow_ui (lo.m_val, 2, max_usable_bits - 1);
+ mpz_neg (lo.m_val, lo.m_val);
+
+ mpz_ui_pow_ui (hi.m_val, 2, max_usable_bits - 1);
+ mpz_sub_ui (hi.m_val, hi.m_val, 1);
+ }
+
+ if (mpz_cmp (m_val, lo.m_val) < 0 || mpz_cmp (m_val, hi.m_val) > 0)
+ error (_("Cannot export value %s as %zu-bits %s integer"
+ " (must be between %s and %s)"),
+ this->str ().c_str (),
+ max_usable_bits,
+ unsigned_p ? _("unsigned") : _("signed"),
+ lo.str ().c_str (),
+ hi.str ().c_str ());
}
- if (mpz_cmp (m_val, lo.m_val) < 0 || mpz_cmp (m_val, hi.m_val) > 0)
- error (_("Cannot export value %s as %zu-bits %s integer"
- " (must be between %s and %s)"),
- this->str ().c_str (),
- max_usable_bits,
- unsigned_p ? _("unsigned") : _("signed"),
- lo.str ().c_str (),
- hi.str ().c_str ());
-
const gdb_mpz *exported_val = this;
gdb_mpz un_signed;
if (sign < 0)
@@ -134,6 +127,28 @@ gdb_mpz::safe_export (gdb::array_view<gdb_byte> buf,
exported_val = &un_signed;
}
+ /* If the value is too large, truncate it. */
+ if (!safe
+ && mpz_sizeinbase (exported_val->m_val, 2) > buf.size () * HOST_CHAR_BIT)
+ {
+ /* If we don't already have a copy, make it now. */
+ if (exported_val != &un_signed)
+ {
+ un_signed = *exported_val;
+ exported_val = &un_signed;
+ }
+
+ un_signed.mask (buf.size () * HOST_CHAR_BIT);
+ }
+
+ /* It's possible that one of the above results in zero, which has to
+ be handled specially. */
+ if (exported_val->sgn () == 0)
+ {
+ memset (buf.data (), 0, buf.size ());
+ return;
+ }
+
/* Do the export into a buffer allocated by GMP itself; that way,
we can detect cases where BUF is not large enough to export
our value, and thus avoid a buffer overlow. Normally, this should
@@ -137,7 +137,20 @@ struct gdb_mpz
UNSIGNED_P indicates whether the number has an unsigned type. */
void write (gdb::array_view<gdb_byte> buf, enum bfd_endian byte_order,
- bool unsigned_p) const;
+ bool unsigned_p) const
+ {
+ export_bits (buf, byte_order == BFD_ENDIAN_BIG ? 1 : -1 /* endian */,
+ unsigned_p, true /* safe */);
+ }
+
+ /* Like write, but truncates the value to the desired number of
+ bytes. */
+ void truncate (gdb::array_view<gdb_byte> buf, enum bfd_endian byte_order,
+ bool unsigned_p) const
+ {
+ export_bits (buf, byte_order == BFD_ENDIAN_BIG ? 1 : -1 /* endian */,
+ unsigned_p, false /* safe */);
+ }
/* Return a string containing VAL. */
std::string str () const { return gmp_string_printf ("%Zd", m_val); }
@@ -337,10 +350,11 @@ struct gdb_mpz
. -1 for least significant byte first; or
. 0 for native endianness.
- An error is raised if BUF is not large enough to contain the value
- being exported. */
- void safe_export (gdb::array_view<gdb_byte> buf,
- int endian, bool unsigned_p) const;
+ If SAFE is true, an error is raised if BUF is not large enough to
+ contain the value being exported. If SAFE is false, the value is
+ truncated to fit in BUF. */
+ void export_bits (gdb::array_view<gdb_byte> buf, int endian, bool unsigned_p,
+ bool safe) const;
friend struct gdb_mpq;
friend struct gdb_mpf;
@@ -590,9 +604,10 @@ gdb_mpz::as_integer () const
{
T result;
- this->safe_export ({(gdb_byte *) &result, sizeof (result)},
+ this->export_bits ({(gdb_byte *) &result, sizeof (result)},
0 /* endian (0 = native) */,
- !std::is_signed<T>::value /* unsigned_p */);
+ !std::is_signed<T>::value /* unsigned_p */,
+ true /* safe */);
return result;
}