diff options
| -rw-r--r-- | gdb/ChangeLog | 7 | ||||
| -rw-r--r-- | gdb/dwarf2loc.c | 56 | ||||
| -rw-r--r-- | gdb/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.dwarf2/var-access.exp | 25 |
4 files changed, 72 insertions, 21 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index d1a400b..8c022a4 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,12 @@ 2017-06-13 Andreas Arnez <arnez@linux.vnet.ibm.com> + * dwarf2loc.c (bits_to_bytes): New function. + (read_pieced_value): Fix offset calculations for register pieces + on big-endian targets. + (write_pieced_value): Likewise. + +2017-06-13 Andreas Arnez <arnez@linux.vnet.ibm.com> + * dwarf2loc.c (read_pieced_value): Remove buffer_size variable. (write_pieced_value): Likewise. diff --git a/gdb/dwarf2loc.c b/gdb/dwarf2loc.c index 6140ee6..a7447cb 100644 --- a/gdb/dwarf2loc.c +++ b/gdb/dwarf2loc.c @@ -1752,6 +1752,15 @@ copy_bitwise_tests (void) #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. */ + +static size_t +bits_to_bytes (ULONGEST start, ULONGEST n_bits) +{ + return (start % 8 + n_bits + 7) / 8; +} + static void read_pieced_value (struct value *v) { @@ -1804,7 +1813,7 @@ read_pieced_value (struct value *v) if (this_size_bits > max_offset - offset) this_size_bits = max_offset - offset; - this_size = (this_size_bits + source_offset_bits % 8 + 7) / 8; + this_size = bits_to_bytes (source_offset_bits, this_size_bits); buffer.reserve (this_size); source_offset = source_offset_bits / 8; intermediate_buffer = buffer.data (); @@ -1817,20 +1826,20 @@ read_pieced_value (struct value *v) struct frame_info *frame = frame_find_by_id (c->frame_id); struct gdbarch *arch = get_frame_arch (frame); int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno); + ULONGEST reg_bits = 8 * register_size (arch, gdb_regnum); int optim, unavail; - LONGEST reg_offset = source_offset; if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG - && this_size < register_size (arch, gdb_regnum)) + && p->size < reg_bits) { /* Big-endian, and we want less than full size. */ - reg_offset = register_size (arch, gdb_regnum) - this_size; - /* We want the lower-order THIS_SIZE_BITS of the bytes - we extract from the register. */ - source_offset_bits += 8 * this_size - this_size_bits; + source_offset_bits += reg_bits - p->size; } + this_size = bits_to_bytes (source_offset_bits, this_size_bits); + buffer.reserve (this_size); - if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, + if (!get_frame_register_bytes (frame, gdb_regnum, + source_offset_bits / 8, this_size, buffer.data (), &optim, &unavail)) { @@ -1844,7 +1853,7 @@ read_pieced_value (struct value *v) } copy_bitwise (contents, dest_offset_bits, - intermediate_buffer, source_offset_bits % 8, + buffer.data (), source_offset_bits % 8, this_size_bits, bits_big_endian); } break; @@ -1969,7 +1978,7 @@ write_pieced_value (struct value *to, struct value *from) if (this_size_bits > max_offset - offset) this_size_bits = max_offset - offset; - this_size = (this_size_bits + dest_offset_bits % 8 + 7) / 8; + this_size = bits_to_bytes (dest_offset_bits, this_size_bits); source_offset = source_offset_bits / 8; dest_offset = dest_offset_bits / 8; @@ -1994,20 +2003,25 @@ write_pieced_value (struct value *to, struct value *from) struct frame_info *frame = frame_find_by_id (c->frame_id); struct gdbarch *arch = get_frame_arch (frame); int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, p->v.regno); - int reg_offset = dest_offset; + ULONGEST reg_bits = 8 * register_size (arch, gdb_regnum); if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG - && this_size <= register_size (arch, gdb_regnum)) + && p->size <= reg_bits) { /* Big-endian, and we want less than full size. */ - reg_offset = register_size (arch, gdb_regnum) - this_size; + dest_offset_bits += reg_bits - p->size; } + this_size = bits_to_bytes (dest_offset_bits, this_size_bits); + buffer.reserve (this_size); - if (need_bitwise) + if (dest_offset_bits % 8 != 0 || this_size_bits % 8 != 0) { + /* Data is copied non-byte-aligned into the register. + Need some bits from original register value. */ int optim, unavail; - if (!get_frame_register_bytes (frame, gdb_regnum, reg_offset, + if (!get_frame_register_bytes (frame, gdb_regnum, + dest_offset_bits / 8, this_size, buffer.data (), &optim, &unavail)) { @@ -2022,14 +2036,14 @@ write_pieced_value (struct value *to, struct value *from) "bitfield; containing word " "is unavailable")); } - copy_bitwise (buffer.data (), dest_offset_bits, - contents, source_offset_bits, - this_size_bits, - bits_big_endian); } - put_frame_register_bytes (frame, gdb_regnum, reg_offset, - this_size, source_buffer); + copy_bitwise (buffer.data (), dest_offset_bits % 8, + contents, source_offset_bits, + this_size_bits, bits_big_endian); + put_frame_register_bytes (frame, gdb_regnum, + dest_offset_bits / 8, + this_size, buffer.data ()); } break; case DWARF_VALUE_MEMORY: diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 256d1fb..e5d303c 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,5 +1,10 @@ 2017-06-13 Andreas Arnez <arnez@linux.vnet.ibm.com> + * gdb.dwarf2/var-access.exp: Add test for non-byte-aligned + register pieces. + +2017-06-13 Andreas Arnez <arnez@linux.vnet.ibm.com> + * gdb.dwarf2/var-access.exp: Add tests for accessing bit-fields located in one or more DWARF pieces. diff --git a/gdb/testsuite/gdb.dwarf2/var-access.exp b/gdb/testsuite/gdb.dwarf2/var-access.exp index 3ba2c08..c533b8d 100644 --- a/gdb/testsuite/gdb.dwarf2/var-access.exp +++ b/gdb/testsuite/gdb.dwarf2/var-access.exp @@ -215,6 +215,19 @@ Dwarf::assemble $asm_file { piece 1 } SPECIAL_expr} } + # Register pieces for bitfield access: 4 bytes optimized + # out, 3 bytes from r0, and 1 byte from r1. + DW_TAG_variable { + {name "t2"} + {type :$struct_t_label} + {location { + piece 4 + regx [lindex $dwarf_regnum 0] + piece 3 + regx [lindex $dwarf_regnum 1] + piece 1 + } SPECIAL_expr} + } } } } @@ -279,3 +292,15 @@ switch $endian { # val gdb_test "print/x a" " = \\{0x0, ${val}, 0x0, 0x0\\}" \ "verify st1 through a" + +switch $endian { big {set val 0x7ffc} little {set val 0x3ffe00} } +gdb_test_no_output "set var \$[lindex $regname 0] = $val" \ + "init t2, first piece" +gdb_test_no_output "set var \$[lindex $regname 1] = 0" \ + "init t2, second piece" +gdb_test "print/d t2" " = \\{u = <optimized out>, x = 0, y = -1, z = 0\\}" \ + "initialized t2 from regs" +gdb_test_no_output "set var t2.y = 2641" +gdb_test_no_output "set var t2.z = -400" +gdb_test_no_output "set var t2.x = 200" +gdb_test "print t2.x + t2.y + t2.z" " = 2441" |