old-cross-binutils/gdb/testsuite/gdb.dwarf2/arr-stride.c

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DWARF: Add array DW_AT_bit_stride and DW_AT_byte_stride support Consider the following declarations in Ada... type Item is range -32 .. 31; for Item'Size use 6; type Table is array (Natural range 0 .. 4) of Item; pragma Pack (Table); ... which declare a packed array whose elements are 6 bits long. The debugger currently does not notice that the array is packed, and thus prints values of this type incorrectly. This can be seen in the "ptype" output: (gdb) ptype table type = array (0 .. 4) of foo.item Normally, the debugger should print: (gdb) ptype table type = array (0 .. 4) of foo.item <packed: 6-bit elements> The debugging information for this array looks like this: .uleb128 0xf # (DIE (0x15c) DW_TAG_array_type) .long .LASF9 # DW_AT_name: "pck__table" .byte 0x6 # DW_AT_bit_stride .long 0x1a9 # DW_AT_type .uleb128 0x10 # (DIE (0x16a) DW_TAG_subrange_type) .long 0x3b # DW_AT_type .byte 0 # DW_AT_lower_bound .byte 0x4 # DW_AT_upper_bound .byte 0 # end of children of DIE 0x15c The interesting part is the DW_AT_bit_stride attribute, which tells the size of the array elements is 6 bits, rather than the normal element type's size. This patch adds support for this attribute by first creating gdbtypes.c::create_array_type_with_stride, which is an enhanced version of create_array_type taking an extra parameter as the stride. The old create_array_type can then be re-implemented very simply by calling the new create_array_type_with_stride. We can then use this new function from dwarf2read, to create arrays with or without stride. gdb/ChangeLog: * gdbtypes.h (create_array_type_with_stride): Add declaration. * gdbtypes.c (create_array_type_with_stride): New function, renaming create_array_type, but with an added parameter called "bit_stride". (create_array_type): Re-implement using create_array_type_with_stride. * dwarf2read.c (read_array_type): Add support for DW_AT_byte_stride and DW_AT_bit_stride attributes. gdb/testsuite/ChangeLog: * gdb.dwarf2/arr-stride.c: New file. * gdb.dwarf2/arr-stride.exp: New file. The test, relying purely on generating an assembly file, only verifies the type description of our array. But I was also able to verify manually that the debugger print values of these types correctly as well (which was not the case prior to this patch).
2014-01-29 13:39:56 +00:00
/* Copyright 2014 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
int
main (void)
{
return 0;
}