From: Joel Brobecker Date: Wed, 14 Nov 2018 23:18:49 +0000 (-0500) Subject: delete ada-lang.c::move_bits, sharing and re-using copy_bitwise instead X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=a99bc3d23c133fe80f7ccac44246a471fb075bc3;p=binutils-gdb.git delete ada-lang.c::move_bits, sharing and re-using copy_bitwise instead This patch deletes ada-lang.c's move_bits function entirely, and replaces all calls to it by calls to copy_bitwise instead. Because the latter function was declared locally inside dwarf2loc.c, this patch also move the function to a common area, and makes it non-static. gdb/ChangeLog: * ada-lang.c (move_bits): Delete. Update all callers to use copy_bitwise instead. * dwarf2loc.c (copy_bitwise, bits_to_str::bits_to_str) (selftests::check_copy_bitwise, selftests::copy_bitwise_tests): Move from here to utils.c. (_initialize_dwarf2loc): Remove call to register copy_bitwise selftests. * utils.h (copy_bitwise): Add declaration. * utils.c (copy_bitwise, bits_to_str::bits_to_str) (selftests::check_copy_bitwise, selftests::copy_bitwise_tests): Moved here from dwarf2loc.c. (_initialize_utils): Register copy_bitwise selftests. Tested on x86_64-linux, no regression. Also tested using AdaCore's testsuite on a collection of small endian and big endian platforms. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 6ce18fe8bf3..4610293d700 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,18 @@ +2018-11-14 Joel Brobecker + + * ada-lang.c (move_bits): Delete. Update all callers to use + copy_bitwise instead. + * dwarf2loc.c (copy_bitwise, bits_to_str::bits_to_str) + (selftests::check_copy_bitwise, selftests::copy_bitwise_tests): + Move from here to utils.c. + (_initialize_dwarf2loc): Remove call to register copy_bitwise + selftests. + * utils.h (copy_bitwise): Add declaration. + * utils.c (copy_bitwise, bits_to_str::bits_to_str) + (selftests::check_copy_bitwise, selftests::copy_bitwise_tests): + Moved here from dwarf2loc.c. + (_initialize_utils): Register copy_bitwise selftests. + 2018-11-14 Jim Wilson * riscv-tdep.c (struct riscv_arg_info): New field is_unnamed. diff --git a/gdb/ada-lang.c b/gdb/ada-lang.c index b7cb122f87c..8967cf17e32 100644 --- a/gdb/ada-lang.c +++ b/gdb/ada-lang.c @@ -190,8 +190,6 @@ static int ada_is_unconstrained_packed_array_type (struct type *); static struct value *value_subscript_packed (struct value *, int, struct value **); -static void move_bits (gdb_byte *, int, const gdb_byte *, int, int, int); - static struct value *coerce_unspec_val_to_type (struct value *, struct type *); @@ -2669,72 +2667,6 @@ ada_value_primitive_packed_val (struct value *obj, const gdb_byte *valaddr, return v; } -/* Move N bits from SOURCE, starting at bit offset SRC_OFFSET to - TARGET, starting at bit offset TARG_OFFSET. SOURCE and TARGET must - not overlap. */ -static void -move_bits (gdb_byte *target, int targ_offset, const gdb_byte *source, - int src_offset, int n, int bits_big_endian_p) -{ - unsigned int accum, mask; - int accum_bits, chunk_size; - - target += targ_offset / HOST_CHAR_BIT; - targ_offset %= HOST_CHAR_BIT; - source += src_offset / HOST_CHAR_BIT; - src_offset %= HOST_CHAR_BIT; - if (bits_big_endian_p) - { - accum = (unsigned char) *source; - source += 1; - accum_bits = HOST_CHAR_BIT - src_offset; - - while (n > 0) - { - int unused_right; - - accum = (accum << HOST_CHAR_BIT) + (unsigned char) *source; - accum_bits += HOST_CHAR_BIT; - source += 1; - chunk_size = HOST_CHAR_BIT - targ_offset; - if (chunk_size > n) - chunk_size = n; - unused_right = HOST_CHAR_BIT - (chunk_size + targ_offset); - mask = ((1 << chunk_size) - 1) << unused_right; - *target = - (*target & ~mask) - | ((accum >> (accum_bits - chunk_size - unused_right)) & mask); - n -= chunk_size; - accum_bits -= chunk_size; - target += 1; - targ_offset = 0; - } - } - else - { - accum = (unsigned char) *source >> src_offset; - source += 1; - accum_bits = HOST_CHAR_BIT - src_offset; - - while (n > 0) - { - accum = accum + ((unsigned char) *source << accum_bits); - accum_bits += HOST_CHAR_BIT; - source += 1; - chunk_size = HOST_CHAR_BIT - targ_offset; - if (chunk_size > n) - chunk_size = n; - mask = ((1 << chunk_size) - 1) << targ_offset; - *target = (*target & ~mask) | ((accum << targ_offset) & mask); - n -= chunk_size; - accum_bits -= chunk_size; - accum >>= chunk_size; - target += 1; - targ_offset = 0; - } - } -} - /* Store the contents of FROMVAL into the location of TOVAL. Return a new value with the location of TOVAL and contents of FROMVAL. Handles assignment into packed fields that have @@ -2777,11 +2709,11 @@ ada_value_assign (struct value *toval, struct value *fromval) if (from_size == 0) from_size = TYPE_LENGTH (value_type (fromval)) * TARGET_CHAR_BIT; if (gdbarch_bits_big_endian (get_type_arch (type))) - move_bits (buffer, value_bitpos (toval), - value_contents (fromval), from_size - bits, bits, 1); + copy_bitwise (buffer, value_bitpos (toval), + value_contents (fromval), from_size - bits, bits, 1); else - move_bits (buffer, value_bitpos (toval), - value_contents (fromval), 0, bits, 0); + copy_bitwise (buffer, value_bitpos (toval), + value_contents (fromval), 0, bits, 0); write_memory_with_notification (to_addr, buffer, len); val = value_copy (toval); @@ -2833,14 +2765,14 @@ value_assign_to_component (struct value *container, struct value *component, = TYPE_LENGTH (value_type (component)) * TARGET_CHAR_BIT - bits; else src_offset = 0; - move_bits (value_contents_writeable (container) + offset_in_container, - value_bitpos (container) + bit_offset_in_container, - value_contents (val), src_offset, bits, 1); + copy_bitwise (value_contents_writeable (container) + offset_in_container, + value_bitpos (container) + bit_offset_in_container, + value_contents (val), src_offset, bits, 1); } else - move_bits (value_contents_writeable (container) + offset_in_container, - value_bitpos (container) + bit_offset_in_container, - value_contents (val), 0, bits, 0); + copy_bitwise (value_contents_writeable (container) + offset_in_container, + value_bitpos (container) + bit_offset_in_container, + value_contents (val), 0, bits, 0); } /* Determine if TYPE is an access to an unconstrained array. */ diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c index ee6a8e277c8..caa3ab74aec 100644 --- a/gdb/dwarf2loc.c +++ b/gdb/dwarf2loc.c @@ -1555,236 +1555,6 @@ allocate_piece_closure (struct dwarf2_per_cu_data *per_cu, return c; } -/* Copy NBITS bits from SOURCE to DEST starting at the given bit - offsets. Use the bit order as specified by BITS_BIG_ENDIAN. - Source and destination buffers must not overlap. */ - -static void -copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, - const gdb_byte *source, ULONGEST source_offset, - ULONGEST nbits, int bits_big_endian) -{ - unsigned int buf, avail; - - if (nbits == 0) - return; - - if (bits_big_endian) - { - /* Start from the end, then work backwards. */ - dest_offset += nbits - 1; - dest += dest_offset / 8; - dest_offset = 7 - dest_offset % 8; - source_offset += nbits - 1; - source += source_offset / 8; - source_offset = 7 - source_offset % 8; - } - else - { - dest += dest_offset / 8; - dest_offset %= 8; - source += source_offset / 8; - source_offset %= 8; - } - - /* Fill BUF with DEST_OFFSET bits from the destination and 8 - - SOURCE_OFFSET bits from the source. */ - buf = *(bits_big_endian ? source-- : source++) >> source_offset; - buf <<= dest_offset; - buf |= *dest & ((1 << dest_offset) - 1); - - /* NBITS: bits yet to be written; AVAIL: BUF's fill level. */ - nbits += dest_offset; - avail = dest_offset + 8 - source_offset; - - /* Flush 8 bits from BUF, if appropriate. */ - if (nbits >= 8 && avail >= 8) - { - *(bits_big_endian ? dest-- : dest++) = buf; - buf >>= 8; - avail -= 8; - nbits -= 8; - } - - /* Copy the middle part. */ - if (nbits >= 8) - { - size_t len = nbits / 8; - - /* Use a faster method for byte-aligned copies. */ - if (avail == 0) - { - if (bits_big_endian) - { - dest -= len; - source -= len; - memcpy (dest + 1, source + 1, len); - } - else - { - memcpy (dest, source, len); - dest += len; - source += len; - } - } - else - { - while (len--) - { - buf |= *(bits_big_endian ? source-- : source++) << avail; - *(bits_big_endian ? dest-- : dest++) = buf; - buf >>= 8; - } - } - nbits %= 8; - } - - /* Write the last byte. */ - if (nbits) - { - if (avail < nbits) - buf |= *source << avail; - - buf &= (1 << nbits) - 1; - *dest = (*dest & (~0 << nbits)) | buf; - } -} - -#if GDB_SELF_TEST - -namespace selftests { - -/* Helper function for the unit test of copy_bitwise. Convert NBITS bits - out of BITS, starting at OFFS, to the respective '0'/'1'-string. MSB0 - specifies whether to assume big endian bit numbering. Store the - resulting (not null-terminated) string at STR. */ - -static void -bits_to_str (char *str, const gdb_byte *bits, ULONGEST offs, - ULONGEST nbits, int msb0) -{ - unsigned int j; - size_t i; - - for (i = offs / 8, j = offs % 8; nbits; i++, j = 0) - { - unsigned int ch = bits[i]; - for (; j < 8 && nbits; j++, nbits--) - *str++ = (ch & (msb0 ? (1 << (7 - j)) : (1 << j))) ? '1' : '0'; - } -} - -/* Check one invocation of copy_bitwise with the given parameters. */ - -static void -check_copy_bitwise (const gdb_byte *dest, unsigned int dest_offset, - const gdb_byte *source, unsigned int source_offset, - unsigned int nbits, int msb0) -{ - size_t len = align_up (dest_offset + nbits, 8); - char *expected = (char *) alloca (len + 1); - char *actual = (char *) alloca (len + 1); - gdb_byte *buf = (gdb_byte *) alloca (len / 8); - - /* Compose a '0'/'1'-string that represents the expected result of - copy_bitwise below: - Bits from [0, DEST_OFFSET) are filled from DEST. - Bits from [DEST_OFFSET, DEST_OFFSET + NBITS) are filled from SOURCE. - Bits from [DEST_OFFSET + NBITS, LEN) are filled from DEST. - - E.g., with: - dest_offset: 4 - nbits: 2 - len: 8 - dest: 00000000 - source: 11111111 - - We should end up with: - buf: 00001100 - DDDDSSDD (D=dest, S=source) - */ - bits_to_str (expected, dest, 0, len, msb0); - bits_to_str (expected + dest_offset, source, source_offset, nbits, msb0); - - /* Fill BUF with data from DEST, apply copy_bitwise, and convert the - result to a '0'/'1'-string. */ - memcpy (buf, dest, len / 8); - copy_bitwise (buf, dest_offset, source, source_offset, nbits, msb0); - bits_to_str (actual, buf, 0, len, msb0); - - /* Compare the resulting strings. */ - expected[len] = actual[len] = '\0'; - if (strcmp (expected, actual) != 0) - error (_("copy_bitwise %s != %s (%u+%u -> %u)"), - expected, actual, source_offset, nbits, dest_offset); -} - -/* Unit test for copy_bitwise. */ - -static void -copy_bitwise_tests (void) -{ - /* Data to be used as both source and destination buffers. The two - arrays below represent the lsb0- and msb0- encoded versions of the - following bit string, respectively: - 00000000 00011111 11111111 01001000 10100101 11110010 - This pattern is chosen such that it contains: - - constant 0- and 1- chunks of more than a full byte; - - 0/1- and 1/0 transitions on all bit positions within a byte; - - several sufficiently asymmetric bytes. - */ - static const gdb_byte data_lsb0[] = { - 0x00, 0xf8, 0xff, 0x12, 0xa5, 0x4f - }; - static const gdb_byte data_msb0[] = { - 0x00, 0x1f, 0xff, 0x48, 0xa5, 0xf2 - }; - - constexpr size_t data_nbits = 8 * sizeof (data_lsb0); - constexpr unsigned max_nbits = 24; - - /* Try all combinations of: - lsb0/msb0 bit order (using the respective data array) - X [0, MAX_NBITS] copy bit width - X feasible source offsets for the given copy bit width - X feasible destination offsets - */ - for (int msb0 = 0; msb0 < 2; msb0++) - { - const gdb_byte *data = msb0 ? data_msb0 : data_lsb0; - - for (unsigned int nbits = 1; nbits <= max_nbits; nbits++) - { - const unsigned int max_offset = data_nbits - nbits; - - for (unsigned source_offset = 0; - source_offset <= max_offset; - source_offset++) - { - for (unsigned dest_offset = 0; - dest_offset <= max_offset; - dest_offset++) - { - check_copy_bitwise (data + dest_offset / 8, - dest_offset % 8, - data + source_offset / 8, - source_offset % 8, - nbits, msb0); - } - } - } - - /* Special cases: copy all, copy nothing. */ - check_copy_bitwise (data_lsb0, 0, data_msb0, 0, data_nbits, msb0); - check_copy_bitwise (data_msb0, 0, data_lsb0, 0, data_nbits, msb0); - check_copy_bitwise (data, data_nbits - 7, data, 9, 0, msb0); - } -} - -} /* namespace selftests */ - -#endif /* GDB_SELF_TEST */ - /* Return the number of bytes overlapping a contiguous chunk of N_BITS bits whose first bit is located at bit offset START. */ @@ -4737,8 +4507,4 @@ _initialize_dwarf2loc (void) NULL, show_entry_values_debug, &setdebuglist, &showdebuglist); - -#if GDB_SELF_TEST - selftests::register_test ("copy_bitwise", selftests::copy_bitwise_tests); -#endif } diff --git a/gdb/utils.c b/gdb/utils.c index 8d4a744e718..c088d8b5f4b 100644 --- a/gdb/utils.c +++ b/gdb/utils.c @@ -3219,6 +3219,234 @@ strip_leading_path_elements (const char *path, int n) return p; } +/* See utils.h. */ + +void +copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, + const gdb_byte *source, ULONGEST source_offset, + ULONGEST nbits, int bits_big_endian) +{ + unsigned int buf, avail; + + if (nbits == 0) + return; + + if (bits_big_endian) + { + /* Start from the end, then work backwards. */ + dest_offset += nbits - 1; + dest += dest_offset / 8; + dest_offset = 7 - dest_offset % 8; + source_offset += nbits - 1; + source += source_offset / 8; + source_offset = 7 - source_offset % 8; + } + else + { + dest += dest_offset / 8; + dest_offset %= 8; + source += source_offset / 8; + source_offset %= 8; + } + + /* Fill BUF with DEST_OFFSET bits from the destination and 8 - + SOURCE_OFFSET bits from the source. */ + buf = *(bits_big_endian ? source-- : source++) >> source_offset; + buf <<= dest_offset; + buf |= *dest & ((1 << dest_offset) - 1); + + /* NBITS: bits yet to be written; AVAIL: BUF's fill level. */ + nbits += dest_offset; + avail = dest_offset + 8 - source_offset; + + /* Flush 8 bits from BUF, if appropriate. */ + if (nbits >= 8 && avail >= 8) + { + *(bits_big_endian ? dest-- : dest++) = buf; + buf >>= 8; + avail -= 8; + nbits -= 8; + } + + /* Copy the middle part. */ + if (nbits >= 8) + { + size_t len = nbits / 8; + + /* Use a faster method for byte-aligned copies. */ + if (avail == 0) + { + if (bits_big_endian) + { + dest -= len; + source -= len; + memcpy (dest + 1, source + 1, len); + } + else + { + memcpy (dest, source, len); + dest += len; + source += len; + } + } + else + { + while (len--) + { + buf |= *(bits_big_endian ? source-- : source++) << avail; + *(bits_big_endian ? dest-- : dest++) = buf; + buf >>= 8; + } + } + nbits %= 8; + } + + /* Write the last byte. */ + if (nbits) + { + if (avail < nbits) + buf |= *source << avail; + + buf &= (1 << nbits) - 1; + *dest = (*dest & (~0 << nbits)) | buf; + } +} + +#if GDB_SELF_TEST + +namespace selftests { + +/* Helper function for the unit test of copy_bitwise. Convert NBITS bits + out of BITS, starting at OFFS, to the respective '0'/'1'-string. MSB0 + specifies whether to assume big endian bit numbering. Store the + resulting (not null-terminated) string at STR. */ + +static void +bits_to_str (char *str, const gdb_byte *bits, ULONGEST offs, + ULONGEST nbits, int msb0) +{ + unsigned int j; + size_t i; + + for (i = offs / 8, j = offs % 8; nbits; i++, j = 0) + { + unsigned int ch = bits[i]; + for (; j < 8 && nbits; j++, nbits--) + *str++ = (ch & (msb0 ? (1 << (7 - j)) : (1 << j))) ? '1' : '0'; + } +} + +/* Check one invocation of copy_bitwise with the given parameters. */ + +static void +check_copy_bitwise (const gdb_byte *dest, unsigned int dest_offset, + const gdb_byte *source, unsigned int source_offset, + unsigned int nbits, int msb0) +{ + size_t len = align_up (dest_offset + nbits, 8); + char *expected = (char *) alloca (len + 1); + char *actual = (char *) alloca (len + 1); + gdb_byte *buf = (gdb_byte *) alloca (len / 8); + + /* Compose a '0'/'1'-string that represents the expected result of + copy_bitwise below: + Bits from [0, DEST_OFFSET) are filled from DEST. + Bits from [DEST_OFFSET, DEST_OFFSET + NBITS) are filled from SOURCE. + Bits from [DEST_OFFSET + NBITS, LEN) are filled from DEST. + + E.g., with: + dest_offset: 4 + nbits: 2 + len: 8 + dest: 00000000 + source: 11111111 + + We should end up with: + buf: 00001100 + DDDDSSDD (D=dest, S=source) + */ + bits_to_str (expected, dest, 0, len, msb0); + bits_to_str (expected + dest_offset, source, source_offset, nbits, msb0); + + /* Fill BUF with data from DEST, apply copy_bitwise, and convert the + result to a '0'/'1'-string. */ + memcpy (buf, dest, len / 8); + copy_bitwise (buf, dest_offset, source, source_offset, nbits, msb0); + bits_to_str (actual, buf, 0, len, msb0); + + /* Compare the resulting strings. */ + expected[len] = actual[len] = '\0'; + if (strcmp (expected, actual) != 0) + error (_("copy_bitwise %s != %s (%u+%u -> %u)"), + expected, actual, source_offset, nbits, dest_offset); +} + +/* Unit test for copy_bitwise. */ + +static void +copy_bitwise_tests (void) +{ + /* Data to be used as both source and destination buffers. The two + arrays below represent the lsb0- and msb0- encoded versions of the + following bit string, respectively: + 00000000 00011111 11111111 01001000 10100101 11110010 + This pattern is chosen such that it contains: + - constant 0- and 1- chunks of more than a full byte; + - 0/1- and 1/0 transitions on all bit positions within a byte; + - several sufficiently asymmetric bytes. + */ + static const gdb_byte data_lsb0[] = { + 0x00, 0xf8, 0xff, 0x12, 0xa5, 0x4f + }; + static const gdb_byte data_msb0[] = { + 0x00, 0x1f, 0xff, 0x48, 0xa5, 0xf2 + }; + + constexpr size_t data_nbits = 8 * sizeof (data_lsb0); + constexpr unsigned max_nbits = 24; + + /* Try all combinations of: + lsb0/msb0 bit order (using the respective data array) + X [0, MAX_NBITS] copy bit width + X feasible source offsets for the given copy bit width + X feasible destination offsets + */ + for (int msb0 = 0; msb0 < 2; msb0++) + { + const gdb_byte *data = msb0 ? data_msb0 : data_lsb0; + + for (unsigned int nbits = 1; nbits <= max_nbits; nbits++) + { + const unsigned int max_offset = data_nbits - nbits; + + for (unsigned source_offset = 0; + source_offset <= max_offset; + source_offset++) + { + for (unsigned dest_offset = 0; + dest_offset <= max_offset; + dest_offset++) + { + check_copy_bitwise (data + dest_offset / 8, + dest_offset % 8, + data + source_offset / 8, + source_offset % 8, + nbits, msb0); + } + } + } + + /* Special cases: copy all, copy nothing. */ + check_copy_bitwise (data_lsb0, 0, data_msb0, 0, data_nbits, msb0); + check_copy_bitwise (data_msb0, 0, data_lsb0, 0, data_nbits, msb0); + check_copy_bitwise (data, data_nbits - 7, data, 9, 0, msb0); + } +} + +} /* namespace selftests */ + +#endif /* GDB_SELF_TEST */ + void _initialize_utils (void) { @@ -3228,5 +3456,6 @@ _initialize_utils (void) #if GDB_SELF_TEST selftests::register_test ("gdb_realpath", gdb_realpath_tests); + selftests::register_test ("copy_bitwise", selftests::copy_bitwise_tests); #endif } diff --git a/gdb/utils.h b/gdb/utils.h index fa9a59087da..08a29af1dc3 100644 --- a/gdb/utils.h +++ b/gdb/utils.h @@ -519,4 +519,12 @@ extern void dump_core (void); extern char *make_hex_string (const gdb_byte *data, size_t length); +/* Copy NBITS bits from SOURCE to DEST starting at the given bit + offsets. Use the bit order as specified by BITS_BIG_ENDIAN. + Source and destination buffers must not overlap. */ + +extern void copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, + const gdb_byte *source, ULONGEST source_offset, + ULONGEST nbits, int bits_big_endian); + #endif /* UTILS_H */