20a5fcbd5b
PR symtab/25470 points out that the Zig programming language allows integers of various bit sizes (including zero), not just sizes that are a multiple of 8. This is supported in DWARF by applying both a byte size and a DW_AT_bit_size. This patch adds support for this feature to integer and boolean types. Other base types are not handled -- for floating-point types, this didn't seem to make sense, and for character types I didn't see much need. (These can be added later if desired.) I've also added support for DW_AT_data_bit_offset at the same time. I don't know whether the Zig compiler requires this, but it was described in the same section in the DWARF standard and was easy to add. A new test case is supplied, using the DWARF assembler. gdb/ChangeLog 2020-09-23 Tom Tromey <tom@tromey.com> PR symtab/25470: * value.c (unpack_long, pack_long, pack_unsigned_long): Handle bit offset and bit size. * printcmd.c (print_scalar_formatted): Handle zero-length integer. (print_scalar_formatted): Use bit_size_differs_p. * gdbtypes.h (enum type_specific_kind) <TYPE_SPECIFIC_INT>: New constant. (union type_specific): <int_stuff>: New member. (struct type) <bit_size_differs_p, bit_size, bit_offset>: New methods. * gdbtypes.c (init_integer_type, init_boolean_type): Initialize TYPE_SPECIFIC_FIELD. (recursive_dump_type, copy_type_recursive): Update. * dwarf2/read.c (read_base_type): Handle DW_AT_bit_size and DW_AT_data_bit_offset. gdb/testsuite/ChangeLog 2020-09-23 Tom Tromey <tom@tromey.com> * gdb.dwarf2/intbits.exp: New file. * gdb.dwarf2/intbits.c: New file.
48 lines
1.7 KiB
C
48 lines
1.7 KiB
C
/* Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* A 16 bit slot holding a 7-bit value of -1. Note that, for all
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these values, we explicitly set the endian-ness in the DWARF to
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avoid issues. */
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unsigned char i16_m1[2] = { 0x7f, 0 };
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/* A 16 bit slot holding a 1-bit value of 1 at offset 2. */
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unsigned char u16_1[2] = { 0x4, 0 };
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/* A 32 bit slot holding a 17-bit value of -2. */
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unsigned char u32_m2[4] = { 0xfe, 0xff, 0x01, 0 };
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/* A 32 bit slot holding a 31 bit value of 1. The high bit should be
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ignored when reading. */
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unsigned char u32_1[4] = { 1, 0, 0, 0x80 };
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/* A 32 bit slot holding a 31 bit value of 1, offset by 1 bit. */
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unsigned char u32_1_off[4] = { 2, 0, 0, 0 };
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/* A 32 bit slot holding a 30 bit value of 1, offset by 1 bit.
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Big-endian. */
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unsigned char be30_1_off[4] = { 0x80, 0, 0, 2 };
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/* A 32 bit slot holding a 0 bit value. We don't use 0 in the array
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here, to catch any situation where gdb tries to use the memory. */
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unsigned char u32_0[4] = { 0xff, 0xff, 0xff, 0xff };
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int
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main (void)
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{
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return 0;
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}
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