diff options
| -rw-r--r-- | gdb/ChangeLog | 10 | ||||
| -rw-r--r-- | gdb/dwarf2loc.c | 140 | ||||
| -rw-r--r-- | gdb/selftest.c | 3 |
3 files changed, 151 insertions, 2 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index aa2fe41..d667a37 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,4 +1,14 @@ 2016-11-24 Andreas Arnez <arnez@linux.vnet.ibm.com> + Pedro Alves <palves@redhat.com> + + * dwarf2loc.c (bits_to_str, check_copy_bitwise) + (copy_bitwise_tests): New functions. + (_initialize_dwarf2loc): Register the new function + copy_bitwise_tests as a unit test. + * selftest.c (run_self_tests): Improve the failure message's + wording and formatting. + +2016-11-24 Andreas Arnez <arnez@linux.vnet.ibm.com> * dwarf2loc.c (extract_bits_primitive): Remove. (extract_bits): Remove. diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c index b238133..61f197b 100644 --- a/gdb/dwarf2loc.c +++ b/gdb/dwarf2loc.c @@ -38,6 +38,7 @@ #include "dwarf2loc.h" #include "dwarf2-frame.h" #include "compile/compile.h" +#include "selftest.h" #include <algorithm> #include <vector> @@ -1567,6 +1568,141 @@ copy_bitwise (gdb_byte *dest, ULONGEST dest_offset, } } +#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 */ + static void read_pieced_value (struct value *v) { @@ -4527,4 +4663,8 @@ _initialize_dwarf2loc (void) NULL, show_entry_values_debug, &setdebuglist, &showdebuglist); + +#if GDB_SELF_TEST + register_self_test (selftests::copy_bitwise_tests); +#endif } diff --git a/gdb/selftest.c b/gdb/selftest.c index 110b9e5..f771e57 100644 --- a/gdb/selftest.c +++ b/gdb/selftest.c @@ -50,8 +50,7 @@ run_self_tests (void) CATCH (ex, RETURN_MASK_ERROR) { ++failed; - exception_fprintf (gdb_stderr, ex, - _("Self test threw exception")); + exception_fprintf (gdb_stderr, ex, _("Self test failed: ")); } END_CATCH } |