diff options
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/values.c | 27 |
2 files changed, 18 insertions, 15 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 19c19db..05c2613 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2004-11-01 Paul N. Hilfinger <Hilfinger@gnat.com> + + * values.c (modify_field): Correct handling of bit-fields that + don't fit in 32 bits. Use unsigned operations throughout and + simplify the code a bit. Document preconditions. + 2004-10-31 Andrew Cagney <cagney@gnu.org> * config/pa/tm-linux.h: Delete #undef IN_SOLIB_CALL_TRAMPOLINE. diff --git a/gdb/values.c b/gdb/values.c index eaf3765..14c980b 100644 --- a/gdb/values.c +++ b/gdb/values.c @@ -1070,45 +1070,42 @@ unpack_field_as_long (struct type *type, const char *valaddr, int fieldno) /* Modify the value of a bitfield. ADDR points to a block of memory in target byte order; the bitfield starts in the byte pointed to. FIELDVAL is the desired value of the field, in host byte order. BITPOS and BITSIZE - indicate which bits (in target bit order) comprise the bitfield. */ + indicate which bits (in target bit order) comprise the bitfield. + Requires 0 < BITSIZE <= lbits, 0 <= BITPOS+BITSIZE <= lbits, and + 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */ void modify_field (char *addr, LONGEST fieldval, int bitpos, int bitsize) { - LONGEST oword; + ULONGEST oword; + ULONGEST mask = (ULONGEST) -1 >> (8 * sizeof (ULONGEST) - bitsize); /* If a negative fieldval fits in the field in question, chop off the sign extension bits. */ - if (bitsize < (8 * (int) sizeof (fieldval)) - && (~fieldval & ~((1 << (bitsize - 1)) - 1)) == 0) - fieldval = fieldval & ((1 << bitsize) - 1); + if ((~fieldval & ~(mask >> 1)) == 0) + fieldval &= mask; /* Warn if value is too big to fit in the field in question. */ - if (bitsize < (8 * (int) sizeof (fieldval)) - && 0 != (fieldval & ~((1 << bitsize) - 1))) + if (0 != (fieldval & ~mask)) { /* FIXME: would like to include fieldval in the message, but we don't have a sprintf_longest. */ warning ("Value does not fit in %d bits.", bitsize); /* Truncate it, otherwise adjoining fields may be corrupted. */ - fieldval = fieldval & ((1 << bitsize) - 1); + fieldval &= mask; } - oword = extract_signed_integer (addr, sizeof oword); + oword = extract_unsigned_integer (addr, sizeof oword); /* Shifting for bit field depends on endianness of the target machine. */ if (BITS_BIG_ENDIAN) bitpos = sizeof (oword) * 8 - bitpos - bitsize; - /* Mask out old value, while avoiding shifts >= size of oword */ - if (bitsize < 8 * (int) sizeof (oword)) - oword &= ~(((((ULONGEST) 1) << bitsize) - 1) << bitpos); - else - oword &= ~((~(ULONGEST) 0) << bitpos); + oword &= ~(mask << bitpos); oword |= fieldval << bitpos; - store_signed_integer (addr, sizeof oword, oword); + store_unsigned_integer (addr, sizeof oword, oword); } /* Convert C numbers into newly allocated values */ |