4671 lines
132 KiB
C
4671 lines
132 KiB
C
/* DWARF 2 location expression support for GDB.
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Copyright (C) 2003-2017 Free Software Foundation, Inc.
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Contributed by Daniel Jacobowitz, MontaVista Software, 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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#include "defs.h"
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#include "ui-out.h"
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#include "value.h"
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#include "frame.h"
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#include "gdbcore.h"
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#include "target.h"
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#include "inferior.h"
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#include "ax.h"
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#include "ax-gdb.h"
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#include "regcache.h"
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#include "objfiles.h"
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#include "block.h"
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#include "gdbcmd.h"
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#include "complaints.h"
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#include "dwarf2.h"
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#include "dwarf2expr.h"
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#include "dwarf2loc.h"
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#include "dwarf2-frame.h"
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#include "compile/compile.h"
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#include "selftest.h"
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#include <algorithm>
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#include <vector>
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#include <unordered_set>
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#include "common/underlying.h"
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#include "common/byte-vector.h"
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extern int dwarf_always_disassemble;
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static struct value *dwarf2_evaluate_loc_desc_full (struct type *type,
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struct frame_info *frame,
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const gdb_byte *data,
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size_t size,
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struct dwarf2_per_cu_data *per_cu,
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struct type *subobj_type,
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LONGEST subobj_byte_offset);
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static struct call_site_parameter *dwarf_expr_reg_to_entry_parameter
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(struct frame_info *frame,
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enum call_site_parameter_kind kind,
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union call_site_parameter_u kind_u,
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struct dwarf2_per_cu_data **per_cu_return);
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/* Until these have formal names, we define these here.
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ref: http://gcc.gnu.org/wiki/DebugFission
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Each entry in .debug_loc.dwo begins with a byte that describes the entry,
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and is then followed by data specific to that entry. */
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enum debug_loc_kind
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{
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/* Indicates the end of the list of entries. */
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DEBUG_LOC_END_OF_LIST = 0,
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/* This is followed by an unsigned LEB128 number that is an index into
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.debug_addr and specifies the base address for all following entries. */
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DEBUG_LOC_BASE_ADDRESS = 1,
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/* This is followed by two unsigned LEB128 numbers that are indices into
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.debug_addr and specify the beginning and ending addresses, and then
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a normal location expression as in .debug_loc. */
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DEBUG_LOC_START_END = 2,
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/* This is followed by an unsigned LEB128 number that is an index into
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.debug_addr and specifies the beginning address, and a 4 byte unsigned
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number that specifies the length, and then a normal location expression
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as in .debug_loc. */
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DEBUG_LOC_START_LENGTH = 3,
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/* An internal value indicating there is insufficient data. */
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DEBUG_LOC_BUFFER_OVERFLOW = -1,
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/* An internal value indicating an invalid kind of entry was found. */
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DEBUG_LOC_INVALID_ENTRY = -2
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};
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/* Helper function which throws an error if a synthetic pointer is
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invalid. */
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static void
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invalid_synthetic_pointer (void)
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{
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error (_("access outside bounds of object "
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"referenced via synthetic pointer"));
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}
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/* Decode the addresses in a non-dwo .debug_loc entry.
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A pointer to the next byte to examine is returned in *NEW_PTR.
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The encoded low,high addresses are return in *LOW,*HIGH.
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The result indicates the kind of entry found. */
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static enum debug_loc_kind
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decode_debug_loc_addresses (const gdb_byte *loc_ptr, const gdb_byte *buf_end,
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const gdb_byte **new_ptr,
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CORE_ADDR *low, CORE_ADDR *high,
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enum bfd_endian byte_order,
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unsigned int addr_size,
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int signed_addr_p)
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{
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CORE_ADDR base_mask = ~(~(CORE_ADDR)1 << (addr_size * 8 - 1));
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if (buf_end - loc_ptr < 2 * addr_size)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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if (signed_addr_p)
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*low = extract_signed_integer (loc_ptr, addr_size, byte_order);
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else
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*low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
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loc_ptr += addr_size;
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if (signed_addr_p)
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*high = extract_signed_integer (loc_ptr, addr_size, byte_order);
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else
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*high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
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loc_ptr += addr_size;
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*new_ptr = loc_ptr;
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/* A base-address-selection entry. */
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if ((*low & base_mask) == base_mask)
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return DEBUG_LOC_BASE_ADDRESS;
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/* An end-of-list entry. */
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if (*low == 0 && *high == 0)
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return DEBUG_LOC_END_OF_LIST;
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return DEBUG_LOC_START_END;
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}
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/* Decode the addresses in .debug_loclists entry.
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A pointer to the next byte to examine is returned in *NEW_PTR.
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The encoded low,high addresses are return in *LOW,*HIGH.
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The result indicates the kind of entry found. */
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static enum debug_loc_kind
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decode_debug_loclists_addresses (struct dwarf2_per_cu_data *per_cu,
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const gdb_byte *loc_ptr,
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const gdb_byte *buf_end,
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const gdb_byte **new_ptr,
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CORE_ADDR *low, CORE_ADDR *high,
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enum bfd_endian byte_order,
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unsigned int addr_size,
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int signed_addr_p)
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{
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uint64_t u64;
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if (loc_ptr == buf_end)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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switch (*loc_ptr++)
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{
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case DW_LLE_end_of_list:
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*new_ptr = loc_ptr;
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return DEBUG_LOC_END_OF_LIST;
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case DW_LLE_base_address:
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if (loc_ptr + addr_size > buf_end)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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if (signed_addr_p)
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*high = extract_signed_integer (loc_ptr, addr_size, byte_order);
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else
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*high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
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loc_ptr += addr_size;
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*new_ptr = loc_ptr;
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return DEBUG_LOC_BASE_ADDRESS;
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case DW_LLE_offset_pair:
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loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &u64);
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if (loc_ptr == NULL)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*low = u64;
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loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &u64);
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if (loc_ptr == NULL)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*high = u64;
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*new_ptr = loc_ptr;
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return DEBUG_LOC_START_END;
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default:
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return DEBUG_LOC_INVALID_ENTRY;
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}
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}
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/* Decode the addresses in .debug_loc.dwo entry.
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A pointer to the next byte to examine is returned in *NEW_PTR.
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The encoded low,high addresses are return in *LOW,*HIGH.
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The result indicates the kind of entry found. */
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static enum debug_loc_kind
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decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data *per_cu,
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const gdb_byte *loc_ptr,
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const gdb_byte *buf_end,
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const gdb_byte **new_ptr,
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CORE_ADDR *low, CORE_ADDR *high,
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enum bfd_endian byte_order)
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{
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uint64_t low_index, high_index;
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if (loc_ptr == buf_end)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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switch (*loc_ptr++)
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{
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case DW_LLE_GNU_end_of_list_entry:
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*new_ptr = loc_ptr;
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return DEBUG_LOC_END_OF_LIST;
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case DW_LLE_GNU_base_address_selection_entry:
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*low = 0;
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loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &high_index);
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if (loc_ptr == NULL)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*high = dwarf2_read_addr_index (per_cu, high_index);
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*new_ptr = loc_ptr;
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return DEBUG_LOC_BASE_ADDRESS;
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case DW_LLE_GNU_start_end_entry:
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loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &low_index);
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if (loc_ptr == NULL)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*low = dwarf2_read_addr_index (per_cu, low_index);
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loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &high_index);
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if (loc_ptr == NULL)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*high = dwarf2_read_addr_index (per_cu, high_index);
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*new_ptr = loc_ptr;
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return DEBUG_LOC_START_END;
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case DW_LLE_GNU_start_length_entry:
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loc_ptr = gdb_read_uleb128 (loc_ptr, buf_end, &low_index);
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if (loc_ptr == NULL)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*low = dwarf2_read_addr_index (per_cu, low_index);
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if (loc_ptr + 4 > buf_end)
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return DEBUG_LOC_BUFFER_OVERFLOW;
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*high = *low;
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*high += extract_unsigned_integer (loc_ptr, 4, byte_order);
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*new_ptr = loc_ptr + 4;
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return DEBUG_LOC_START_LENGTH;
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default:
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return DEBUG_LOC_INVALID_ENTRY;
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}
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}
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/* A function for dealing with location lists. Given a
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symbol baton (BATON) and a pc value (PC), find the appropriate
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location expression, set *LOCEXPR_LENGTH, and return a pointer
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to the beginning of the expression. Returns NULL on failure.
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For now, only return the first matching location expression; there
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can be more than one in the list. */
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const gdb_byte *
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dwarf2_find_location_expression (struct dwarf2_loclist_baton *baton,
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size_t *locexpr_length, CORE_ADDR pc)
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{
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struct objfile *objfile = dwarf2_per_cu_objfile (baton->per_cu);
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struct gdbarch *gdbarch = get_objfile_arch (objfile);
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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unsigned int addr_size = dwarf2_per_cu_addr_size (baton->per_cu);
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int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
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/* Adjust base_address for relocatable objects. */
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CORE_ADDR base_offset = dwarf2_per_cu_text_offset (baton->per_cu);
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CORE_ADDR base_address = baton->base_address + base_offset;
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const gdb_byte *loc_ptr, *buf_end;
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loc_ptr = baton->data;
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buf_end = baton->data + baton->size;
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while (1)
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{
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CORE_ADDR low = 0, high = 0; /* init for gcc -Wall */
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int length;
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enum debug_loc_kind kind;
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const gdb_byte *new_ptr = NULL; /* init for gcc -Wall */
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if (baton->from_dwo)
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kind = decode_debug_loc_dwo_addresses (baton->per_cu,
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loc_ptr, buf_end, &new_ptr,
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&low, &high, byte_order);
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else if (dwarf2_version (baton->per_cu) < 5)
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kind = decode_debug_loc_addresses (loc_ptr, buf_end, &new_ptr,
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&low, &high,
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byte_order, addr_size,
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signed_addr_p);
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else
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kind = decode_debug_loclists_addresses (baton->per_cu,
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loc_ptr, buf_end, &new_ptr,
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&low, &high, byte_order,
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addr_size, signed_addr_p);
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loc_ptr = new_ptr;
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switch (kind)
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{
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case DEBUG_LOC_END_OF_LIST:
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*locexpr_length = 0;
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return NULL;
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case DEBUG_LOC_BASE_ADDRESS:
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base_address = high + base_offset;
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continue;
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case DEBUG_LOC_START_END:
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case DEBUG_LOC_START_LENGTH:
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break;
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case DEBUG_LOC_BUFFER_OVERFLOW:
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case DEBUG_LOC_INVALID_ENTRY:
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error (_("dwarf2_find_location_expression: "
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"Corrupted DWARF expression."));
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default:
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gdb_assert_not_reached ("bad debug_loc_kind");
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}
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/* Otherwise, a location expression entry.
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If the entry is from a DWO, don't add base address: the entry is from
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.debug_addr which already has the DWARF "base address". We still add
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base_offset in case we're debugging a PIE executable. */
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if (baton->from_dwo)
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{
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low += base_offset;
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high += base_offset;
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}
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else
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{
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low += base_address;
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high += base_address;
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}
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if (dwarf2_version (baton->per_cu) < 5)
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{
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length = extract_unsigned_integer (loc_ptr, 2, byte_order);
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loc_ptr += 2;
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}
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else
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{
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unsigned int bytes_read;
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length = read_unsigned_leb128 (NULL, loc_ptr, &bytes_read);
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loc_ptr += bytes_read;
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}
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if (low == high && pc == low)
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{
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/* This is entry PC record present only at entry point
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of a function. Verify it is really the function entry point. */
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const struct block *pc_block = block_for_pc (pc);
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struct symbol *pc_func = NULL;
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if (pc_block)
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pc_func = block_linkage_function (pc_block);
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if (pc_func && pc == BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func)))
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{
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*locexpr_length = length;
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return loc_ptr;
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}
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}
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if (pc >= low && pc < high)
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{
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*locexpr_length = length;
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return loc_ptr;
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}
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loc_ptr += length;
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}
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}
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/* This is the baton used when performing dwarf2 expression
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evaluation. */
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struct dwarf_expr_baton
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{
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struct frame_info *frame;
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struct dwarf2_per_cu_data *per_cu;
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CORE_ADDR obj_address;
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};
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/* Implement find_frame_base_location method for LOC_BLOCK functions using
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DWARF expression for its DW_AT_frame_base. */
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static void
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locexpr_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc,
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const gdb_byte **start, size_t *length)
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{
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struct dwarf2_locexpr_baton *symbaton
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= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (framefunc);
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*length = symbaton->size;
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*start = symbaton->data;
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}
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||
|
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/* Implement the struct symbol_block_ops::get_frame_base method for
|
||
LOC_BLOCK functions using a DWARF expression as its DW_AT_frame_base. */
|
||
|
||
static CORE_ADDR
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locexpr_get_frame_base (struct symbol *framefunc, struct frame_info *frame)
|
||
{
|
||
struct gdbarch *gdbarch;
|
||
struct type *type;
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||
struct dwarf2_locexpr_baton *dlbaton;
|
||
const gdb_byte *start;
|
||
size_t length;
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struct value *result;
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||
|
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/* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
|
||
Thus, it's supposed to provide the find_frame_base_location method as
|
||
well. */
|
||
gdb_assert (SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location != NULL);
|
||
|
||
gdbarch = get_frame_arch (frame);
|
||
type = builtin_type (gdbarch)->builtin_data_ptr;
|
||
dlbaton = (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (framefunc);
|
||
|
||
SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location
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(framefunc, get_frame_pc (frame), &start, &length);
|
||
result = dwarf2_evaluate_loc_desc (type, frame, start, length,
|
||
dlbaton->per_cu);
|
||
|
||
/* The DW_AT_frame_base attribute contains a location description which
|
||
computes the base address itself. However, the call to
|
||
dwarf2_evaluate_loc_desc returns a value representing a variable at
|
||
that address. The frame base address is thus this variable's
|
||
address. */
|
||
return value_address (result);
|
||
}
|
||
|
||
/* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
|
||
function uses DWARF expression for its DW_AT_frame_base. */
|
||
|
||
const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs =
|
||
{
|
||
locexpr_find_frame_base_location,
|
||
locexpr_get_frame_base
|
||
};
|
||
|
||
/* Implement find_frame_base_location method for LOC_BLOCK functions using
|
||
DWARF location list for its DW_AT_frame_base. */
|
||
|
||
static void
|
||
loclist_find_frame_base_location (struct symbol *framefunc, CORE_ADDR pc,
|
||
const gdb_byte **start, size_t *length)
|
||
{
|
||
struct dwarf2_loclist_baton *symbaton
|
||
= (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (framefunc);
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*start = dwarf2_find_location_expression (symbaton, length, pc);
|
||
}
|
||
|
||
/* Implement the struct symbol_block_ops::get_frame_base method for
|
||
LOC_BLOCK functions using a DWARF location list as its DW_AT_frame_base. */
|
||
|
||
static CORE_ADDR
|
||
loclist_get_frame_base (struct symbol *framefunc, struct frame_info *frame)
|
||
{
|
||
struct gdbarch *gdbarch;
|
||
struct type *type;
|
||
struct dwarf2_loclist_baton *dlbaton;
|
||
const gdb_byte *start;
|
||
size_t length;
|
||
struct value *result;
|
||
|
||
/* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
|
||
Thus, it's supposed to provide the find_frame_base_location method as
|
||
well. */
|
||
gdb_assert (SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location != NULL);
|
||
|
||
gdbarch = get_frame_arch (frame);
|
||
type = builtin_type (gdbarch)->builtin_data_ptr;
|
||
dlbaton = (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (framefunc);
|
||
|
||
SYMBOL_BLOCK_OPS (framefunc)->find_frame_base_location
|
||
(framefunc, get_frame_pc (frame), &start, &length);
|
||
result = dwarf2_evaluate_loc_desc (type, frame, start, length,
|
||
dlbaton->per_cu);
|
||
|
||
/* The DW_AT_frame_base attribute contains a location description which
|
||
computes the base address itself. However, the call to
|
||
dwarf2_evaluate_loc_desc returns a value representing a variable at
|
||
that address. The frame base address is thus this variable's
|
||
address. */
|
||
return value_address (result);
|
||
}
|
||
|
||
/* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
|
||
function uses DWARF location list for its DW_AT_frame_base. */
|
||
|
||
const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs =
|
||
{
|
||
loclist_find_frame_base_location,
|
||
loclist_get_frame_base
|
||
};
|
||
|
||
/* See dwarf2loc.h. */
|
||
|
||
void
|
||
func_get_frame_base_dwarf_block (struct symbol *framefunc, CORE_ADDR pc,
|
||
const gdb_byte **start, size_t *length)
|
||
{
|
||
if (SYMBOL_BLOCK_OPS (framefunc) != NULL)
|
||
{
|
||
const struct symbol_block_ops *ops_block = SYMBOL_BLOCK_OPS (framefunc);
|
||
|
||
ops_block->find_frame_base_location (framefunc, pc, start, length);
|
||
}
|
||
else
|
||
*length = 0;
|
||
|
||
if (*length == 0)
|
||
error (_("Could not find the frame base for \"%s\"."),
|
||
SYMBOL_NATURAL_NAME (framefunc));
|
||
}
|
||
|
||
static CORE_ADDR
|
||
get_frame_pc_for_per_cu_dwarf_call (void *baton)
|
||
{
|
||
dwarf_expr_context *ctx = (dwarf_expr_context *) baton;
|
||
|
||
return ctx->get_frame_pc ();
|
||
}
|
||
|
||
static void
|
||
per_cu_dwarf_call (struct dwarf_expr_context *ctx, cu_offset die_offset,
|
||
struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
struct dwarf2_locexpr_baton block;
|
||
|
||
block = dwarf2_fetch_die_loc_cu_off (die_offset, per_cu,
|
||
get_frame_pc_for_per_cu_dwarf_call,
|
||
ctx);
|
||
|
||
/* DW_OP_call_ref is currently not supported. */
|
||
gdb_assert (block.per_cu == per_cu);
|
||
|
||
ctx->eval (block.data, block.size);
|
||
}
|
||
|
||
class dwarf_evaluate_loc_desc : public dwarf_expr_context
|
||
{
|
||
public:
|
||
|
||
struct frame_info *frame;
|
||
struct dwarf2_per_cu_data *per_cu;
|
||
CORE_ADDR obj_address;
|
||
|
||
/* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
|
||
the frame in BATON. */
|
||
|
||
CORE_ADDR get_frame_cfa () OVERRIDE
|
||
{
|
||
return dwarf2_frame_cfa (frame);
|
||
}
|
||
|
||
/* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
|
||
the frame in BATON. */
|
||
|
||
CORE_ADDR get_frame_pc () OVERRIDE
|
||
{
|
||
return get_frame_address_in_block (frame);
|
||
}
|
||
|
||
/* Using the objfile specified in BATON, find the address for the
|
||
current thread's thread-local storage with offset OFFSET. */
|
||
CORE_ADDR get_tls_address (CORE_ADDR offset) OVERRIDE
|
||
{
|
||
struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
|
||
|
||
return target_translate_tls_address (objfile, offset);
|
||
}
|
||
|
||
/* Helper interface of per_cu_dwarf_call for
|
||
dwarf2_evaluate_loc_desc. */
|
||
|
||
void dwarf_call (cu_offset die_offset) OVERRIDE
|
||
{
|
||
per_cu_dwarf_call (this, die_offset, per_cu);
|
||
}
|
||
|
||
struct type *get_base_type (cu_offset die_offset, int size) OVERRIDE
|
||
{
|
||
struct type *result = dwarf2_get_die_type (die_offset, per_cu);
|
||
if (result == NULL)
|
||
error (_("Could not find type for DW_OP_const_type"));
|
||
if (size != 0 && TYPE_LENGTH (result) != size)
|
||
error (_("DW_OP_const_type has different sizes for type and data"));
|
||
return result;
|
||
}
|
||
|
||
/* Callback function for dwarf2_evaluate_loc_desc.
|
||
Fetch the address indexed by DW_OP_GNU_addr_index. */
|
||
|
||
CORE_ADDR get_addr_index (unsigned int index) OVERRIDE
|
||
{
|
||
return dwarf2_read_addr_index (per_cu, index);
|
||
}
|
||
|
||
/* Callback function for get_object_address. Return the address of the VLA
|
||
object. */
|
||
|
||
CORE_ADDR get_object_address () OVERRIDE
|
||
{
|
||
if (obj_address == 0)
|
||
error (_("Location address is not set."));
|
||
return obj_address;
|
||
}
|
||
|
||
/* Execute DWARF block of call_site_parameter which matches KIND and
|
||
KIND_U. Choose DEREF_SIZE value of that parameter. Search
|
||
caller of this objects's frame.
|
||
|
||
The caller can be from a different CU - per_cu_dwarf_call
|
||
implementation can be more simple as it does not support cross-CU
|
||
DWARF executions. */
|
||
|
||
void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind,
|
||
union call_site_parameter_u kind_u,
|
||
int deref_size) OVERRIDE
|
||
{
|
||
struct frame_info *caller_frame;
|
||
struct dwarf2_per_cu_data *caller_per_cu;
|
||
struct call_site_parameter *parameter;
|
||
const gdb_byte *data_src;
|
||
size_t size;
|
||
|
||
caller_frame = get_prev_frame (frame);
|
||
|
||
parameter = dwarf_expr_reg_to_entry_parameter (frame, kind, kind_u,
|
||
&caller_per_cu);
|
||
data_src = deref_size == -1 ? parameter->value : parameter->data_value;
|
||
size = deref_size == -1 ? parameter->value_size : parameter->data_value_size;
|
||
|
||
/* DEREF_SIZE size is not verified here. */
|
||
if (data_src == NULL)
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("Cannot resolve DW_AT_call_data_value"));
|
||
|
||
scoped_restore save_frame = make_scoped_restore (&this->frame,
|
||
caller_frame);
|
||
scoped_restore save_per_cu = make_scoped_restore (&this->per_cu,
|
||
caller_per_cu);
|
||
scoped_restore save_obj_addr = make_scoped_restore (&this->obj_address,
|
||
(CORE_ADDR) 0);
|
||
|
||
scoped_restore save_arch = make_scoped_restore (&this->gdbarch);
|
||
this->gdbarch
|
||
= get_objfile_arch (dwarf2_per_cu_objfile (per_cu));
|
||
scoped_restore save_addr_size = make_scoped_restore (&this->addr_size);
|
||
this->addr_size = dwarf2_per_cu_addr_size (per_cu);
|
||
scoped_restore save_offset = make_scoped_restore (&this->offset);
|
||
this->offset = dwarf2_per_cu_text_offset (per_cu);
|
||
|
||
this->eval (data_src, size);
|
||
}
|
||
|
||
/* Using the frame specified in BATON, find the location expression
|
||
describing the frame base. Return a pointer to it in START and
|
||
its length in LENGTH. */
|
||
void get_frame_base (const gdb_byte **start, size_t * length) OVERRIDE
|
||
{
|
||
/* FIXME: cagney/2003-03-26: This code should be using
|
||
get_frame_base_address(), and then implement a dwarf2 specific
|
||
this_base method. */
|
||
struct symbol *framefunc;
|
||
const struct block *bl = get_frame_block (frame, NULL);
|
||
|
||
if (bl == NULL)
|
||
error (_("frame address is not available."));
|
||
|
||
/* Use block_linkage_function, which returns a real (not inlined)
|
||
function, instead of get_frame_function, which may return an
|
||
inlined function. */
|
||
framefunc = block_linkage_function (bl);
|
||
|
||
/* If we found a frame-relative symbol then it was certainly within
|
||
some function associated with a frame. If we can't find the frame,
|
||
something has gone wrong. */
|
||
gdb_assert (framefunc != NULL);
|
||
|
||
func_get_frame_base_dwarf_block (framefunc,
|
||
get_frame_address_in_block (frame),
|
||
start, length);
|
||
}
|
||
|
||
/* Read memory at ADDR (length LEN) into BUF. */
|
||
|
||
void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t len) OVERRIDE
|
||
{
|
||
read_memory (addr, buf, len);
|
||
}
|
||
|
||
/* Using the frame specified in BATON, return the value of register
|
||
REGNUM, treated as a pointer. */
|
||
CORE_ADDR read_addr_from_reg (int dwarf_regnum) OVERRIDE
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
int regnum = dwarf_reg_to_regnum_or_error (gdbarch, dwarf_regnum);
|
||
|
||
return address_from_register (regnum, frame);
|
||
}
|
||
|
||
/* Implement "get_reg_value" callback. */
|
||
|
||
struct value *get_reg_value (struct type *type, int dwarf_regnum) OVERRIDE
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (frame);
|
||
int regnum = dwarf_reg_to_regnum_or_error (gdbarch, dwarf_regnum);
|
||
|
||
return value_from_register (type, regnum, frame);
|
||
}
|
||
};
|
||
|
||
/* See dwarf2loc.h. */
|
||
|
||
unsigned int entry_values_debug = 0;
|
||
|
||
/* Helper to set entry_values_debug. */
|
||
|
||
static void
|
||
show_entry_values_debug (struct ui_file *file, int from_tty,
|
||
struct cmd_list_element *c, const char *value)
|
||
{
|
||
fprintf_filtered (file,
|
||
_("Entry values and tail call frames debugging is %s.\n"),
|
||
value);
|
||
}
|
||
|
||
/* Find DW_TAG_call_site's DW_AT_call_target address.
|
||
CALLER_FRAME (for registers) can be NULL if it is not known. This function
|
||
always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */
|
||
|
||
static CORE_ADDR
|
||
call_site_to_target_addr (struct gdbarch *call_site_gdbarch,
|
||
struct call_site *call_site,
|
||
struct frame_info *caller_frame)
|
||
{
|
||
switch (FIELD_LOC_KIND (call_site->target))
|
||
{
|
||
case FIELD_LOC_KIND_DWARF_BLOCK:
|
||
{
|
||
struct dwarf2_locexpr_baton *dwarf_block;
|
||
struct value *val;
|
||
struct type *caller_core_addr_type;
|
||
struct gdbarch *caller_arch;
|
||
|
||
dwarf_block = FIELD_DWARF_BLOCK (call_site->target);
|
||
if (dwarf_block == NULL)
|
||
{
|
||
struct bound_minimal_symbol msym;
|
||
|
||
msym = lookup_minimal_symbol_by_pc (call_site->pc - 1);
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DW_AT_call_target is not specified at %s in %s"),
|
||
paddress (call_site_gdbarch, call_site->pc),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)));
|
||
|
||
}
|
||
if (caller_frame == NULL)
|
||
{
|
||
struct bound_minimal_symbol msym;
|
||
|
||
msym = lookup_minimal_symbol_by_pc (call_site->pc - 1);
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DW_AT_call_target DWARF block resolving "
|
||
"requires known frame which is currently not "
|
||
"available at %s in %s"),
|
||
paddress (call_site_gdbarch, call_site->pc),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)));
|
||
|
||
}
|
||
caller_arch = get_frame_arch (caller_frame);
|
||
caller_core_addr_type = builtin_type (caller_arch)->builtin_func_ptr;
|
||
val = dwarf2_evaluate_loc_desc (caller_core_addr_type, caller_frame,
|
||
dwarf_block->data, dwarf_block->size,
|
||
dwarf_block->per_cu);
|
||
/* DW_AT_call_target is a DWARF expression, not a DWARF location. */
|
||
if (VALUE_LVAL (val) == lval_memory)
|
||
return value_address (val);
|
||
else
|
||
return value_as_address (val);
|
||
}
|
||
|
||
case FIELD_LOC_KIND_PHYSNAME:
|
||
{
|
||
const char *physname;
|
||
struct bound_minimal_symbol msym;
|
||
|
||
physname = FIELD_STATIC_PHYSNAME (call_site->target);
|
||
|
||
/* Handle both the mangled and demangled PHYSNAME. */
|
||
msym = lookup_minimal_symbol (physname, NULL, NULL);
|
||
if (msym.minsym == NULL)
|
||
{
|
||
msym = lookup_minimal_symbol_by_pc (call_site->pc - 1);
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("Cannot find function \"%s\" for a call site target "
|
||
"at %s in %s"),
|
||
physname, paddress (call_site_gdbarch, call_site->pc),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)));
|
||
|
||
}
|
||
return BMSYMBOL_VALUE_ADDRESS (msym);
|
||
}
|
||
|
||
case FIELD_LOC_KIND_PHYSADDR:
|
||
return FIELD_STATIC_PHYSADDR (call_site->target);
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("invalid call site target kind"));
|
||
}
|
||
}
|
||
|
||
/* Convert function entry point exact address ADDR to the function which is
|
||
compliant with TAIL_CALL_LIST_COMPLETE condition. Throw
|
||
NO_ENTRY_VALUE_ERROR otherwise. */
|
||
|
||
static struct symbol *
|
||
func_addr_to_tail_call_list (struct gdbarch *gdbarch, CORE_ADDR addr)
|
||
{
|
||
struct symbol *sym = find_pc_function (addr);
|
||
struct type *type;
|
||
|
||
if (sym == NULL || BLOCK_START (SYMBOL_BLOCK_VALUE (sym)) != addr)
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DW_TAG_call_site resolving failed to find function "
|
||
"name for address %s"),
|
||
paddress (gdbarch, addr));
|
||
|
||
type = SYMBOL_TYPE (sym);
|
||
gdb_assert (TYPE_CODE (type) == TYPE_CODE_FUNC);
|
||
gdb_assert (TYPE_SPECIFIC_FIELD (type) == TYPE_SPECIFIC_FUNC);
|
||
|
||
return sym;
|
||
}
|
||
|
||
/* Verify function with entry point exact address ADDR can never call itself
|
||
via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it
|
||
can call itself via tail calls.
|
||
|
||
If a funtion can tail call itself its entry value based parameters are
|
||
unreliable. There is no verification whether the value of some/all
|
||
parameters is unchanged through the self tail call, we expect if there is
|
||
a self tail call all the parameters can be modified. */
|
||
|
||
static void
|
||
func_verify_no_selftailcall (struct gdbarch *gdbarch, CORE_ADDR verify_addr)
|
||
{
|
||
CORE_ADDR addr;
|
||
|
||
/* The verification is completely unordered. Track here function addresses
|
||
which still need to be iterated. */
|
||
std::vector<CORE_ADDR> todo;
|
||
|
||
/* Track here CORE_ADDRs which were already visited. */
|
||
std::unordered_set<CORE_ADDR> addr_hash;
|
||
|
||
todo.push_back (verify_addr);
|
||
while (!todo.empty ())
|
||
{
|
||
struct symbol *func_sym;
|
||
struct call_site *call_site;
|
||
|
||
addr = todo.back ();
|
||
todo.pop_back ();
|
||
|
||
func_sym = func_addr_to_tail_call_list (gdbarch, addr);
|
||
|
||
for (call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym));
|
||
call_site; call_site = call_site->tail_call_next)
|
||
{
|
||
CORE_ADDR target_addr;
|
||
|
||
/* CALLER_FRAME with registers is not available for tail-call jumped
|
||
frames. */
|
||
target_addr = call_site_to_target_addr (gdbarch, call_site, NULL);
|
||
|
||
if (target_addr == verify_addr)
|
||
{
|
||
struct bound_minimal_symbol msym;
|
||
|
||
msym = lookup_minimal_symbol_by_pc (verify_addr);
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DW_OP_entry_value resolving has found "
|
||
"function \"%s\" at %s can call itself via tail "
|
||
"calls"),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)),
|
||
paddress (gdbarch, verify_addr));
|
||
}
|
||
|
||
if (addr_hash.insert (target_addr).second)
|
||
todo.push_back (target_addr);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for
|
||
ENTRY_VALUES_DEBUG. */
|
||
|
||
static void
|
||
tailcall_dump (struct gdbarch *gdbarch, const struct call_site *call_site)
|
||
{
|
||
CORE_ADDR addr = call_site->pc;
|
||
struct bound_minimal_symbol msym = lookup_minimal_symbol_by_pc (addr - 1);
|
||
|
||
fprintf_unfiltered (gdb_stdlog, " %s(%s)", paddress (gdbarch, addr),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)));
|
||
|
||
}
|
||
|
||
/* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP
|
||
only top callers and bottom callees which are present in both. GDBARCH is
|
||
used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are
|
||
no remaining possibilities to provide unambiguous non-trivial result.
|
||
RESULTP should point to NULL on the first (initialization) call. Caller is
|
||
responsible for xfree of any RESULTP data. */
|
||
|
||
static void
|
||
chain_candidate (struct gdbarch *gdbarch,
|
||
gdb::unique_xmalloc_ptr<struct call_site_chain> *resultp,
|
||
std::vector<struct call_site *> *chain)
|
||
{
|
||
long length = chain->size ();
|
||
int callers, callees, idx;
|
||
|
||
if (*resultp == NULL)
|
||
{
|
||
/* Create the initial chain containing all the passed PCs. */
|
||
|
||
struct call_site_chain *result
|
||
= ((struct call_site_chain *)
|
||
xmalloc (sizeof (*result)
|
||
+ sizeof (*result->call_site) * (length - 1)));
|
||
result->length = length;
|
||
result->callers = result->callees = length;
|
||
if (!chain->empty ())
|
||
memcpy (result->call_site, chain->data (),
|
||
sizeof (*result->call_site) * length);
|
||
resultp->reset (result);
|
||
|
||
if (entry_values_debug)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog, "tailcall: initial:");
|
||
for (idx = 0; idx < length; idx++)
|
||
tailcall_dump (gdbarch, result->call_site[idx]);
|
||
fputc_unfiltered ('\n', gdb_stdlog);
|
||
}
|
||
|
||
return;
|
||
}
|
||
|
||
if (entry_values_debug)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog, "tailcall: compare:");
|
||
for (idx = 0; idx < length; idx++)
|
||
tailcall_dump (gdbarch, chain->at (idx));
|
||
fputc_unfiltered ('\n', gdb_stdlog);
|
||
}
|
||
|
||
/* Intersect callers. */
|
||
|
||
callers = std::min ((long) (*resultp)->callers, length);
|
||
for (idx = 0; idx < callers; idx++)
|
||
if ((*resultp)->call_site[idx] != chain->at (idx))
|
||
{
|
||
(*resultp)->callers = idx;
|
||
break;
|
||
}
|
||
|
||
/* Intersect callees. */
|
||
|
||
callees = std::min ((long) (*resultp)->callees, length);
|
||
for (idx = 0; idx < callees; idx++)
|
||
if ((*resultp)->call_site[(*resultp)->length - 1 - idx]
|
||
!= chain->at (length - 1 - idx))
|
||
{
|
||
(*resultp)->callees = idx;
|
||
break;
|
||
}
|
||
|
||
if (entry_values_debug)
|
||
{
|
||
fprintf_unfiltered (gdb_stdlog, "tailcall: reduced:");
|
||
for (idx = 0; idx < (*resultp)->callers; idx++)
|
||
tailcall_dump (gdbarch, (*resultp)->call_site[idx]);
|
||
fputs_unfiltered (" |", gdb_stdlog);
|
||
for (idx = 0; idx < (*resultp)->callees; idx++)
|
||
tailcall_dump (gdbarch,
|
||
(*resultp)->call_site[(*resultp)->length
|
||
- (*resultp)->callees + idx]);
|
||
fputc_unfiltered ('\n', gdb_stdlog);
|
||
}
|
||
|
||
if ((*resultp)->callers == 0 && (*resultp)->callees == 0)
|
||
{
|
||
/* There are no common callers or callees. It could be also a direct
|
||
call (which has length 0) with ambiguous possibility of an indirect
|
||
call - CALLERS == CALLEES == 0 is valid during the first allocation
|
||
but any subsequence processing of such entry means ambiguity. */
|
||
resultp->reset (NULL);
|
||
return;
|
||
}
|
||
|
||
/* See call_site_find_chain_1 why there is no way to reach the bottom callee
|
||
PC again. In such case there must be two different code paths to reach
|
||
it. CALLERS + CALLEES equal to LENGTH in the case of self tail-call. */
|
||
gdb_assert ((*resultp)->callers + (*resultp)->callees <= (*resultp)->length);
|
||
}
|
||
|
||
/* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
|
||
assumed frames between them use GDBARCH. Use depth first search so we can
|
||
keep single CHAIN of call_site's back to CALLER_PC. Function recursion
|
||
would have needless GDB stack overhead. Caller is responsible for xfree of
|
||
the returned result. Any unreliability results in thrown
|
||
NO_ENTRY_VALUE_ERROR. */
|
||
|
||
static struct call_site_chain *
|
||
call_site_find_chain_1 (struct gdbarch *gdbarch, CORE_ADDR caller_pc,
|
||
CORE_ADDR callee_pc)
|
||
{
|
||
CORE_ADDR save_callee_pc = callee_pc;
|
||
gdb::unique_xmalloc_ptr<struct call_site_chain> retval;
|
||
struct call_site *call_site;
|
||
|
||
/* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's
|
||
call_site nor any possible call_site at CALLEE_PC's function is there.
|
||
Any CALL_SITE in CHAIN will be iterated to its siblings - via
|
||
TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */
|
||
std::vector<struct call_site *> chain;
|
||
|
||
/* We are not interested in the specific PC inside the callee function. */
|
||
callee_pc = get_pc_function_start (callee_pc);
|
||
if (callee_pc == 0)
|
||
throw_error (NO_ENTRY_VALUE_ERROR, _("Unable to find function for PC %s"),
|
||
paddress (gdbarch, save_callee_pc));
|
||
|
||
/* Mark CALL_SITEs so we do not visit the same ones twice. */
|
||
std::unordered_set<CORE_ADDR> addr_hash;
|
||
|
||
/* Do not push CALL_SITE to CHAIN. Push there only the first tail call site
|
||
at the target's function. All the possible tail call sites in the
|
||
target's function will get iterated as already pushed into CHAIN via their
|
||
TAIL_CALL_NEXT. */
|
||
call_site = call_site_for_pc (gdbarch, caller_pc);
|
||
|
||
while (call_site)
|
||
{
|
||
CORE_ADDR target_func_addr;
|
||
struct call_site *target_call_site;
|
||
|
||
/* CALLER_FRAME with registers is not available for tail-call jumped
|
||
frames. */
|
||
target_func_addr = call_site_to_target_addr (gdbarch, call_site, NULL);
|
||
|
||
if (target_func_addr == callee_pc)
|
||
{
|
||
chain_candidate (gdbarch, &retval, &chain);
|
||
if (retval == NULL)
|
||
break;
|
||
|
||
/* There is no way to reach CALLEE_PC again as we would prevent
|
||
entering it twice as being already marked in ADDR_HASH. */
|
||
target_call_site = NULL;
|
||
}
|
||
else
|
||
{
|
||
struct symbol *target_func;
|
||
|
||
target_func = func_addr_to_tail_call_list (gdbarch, target_func_addr);
|
||
target_call_site = TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func));
|
||
}
|
||
|
||
do
|
||
{
|
||
/* Attempt to visit TARGET_CALL_SITE. */
|
||
|
||
if (target_call_site)
|
||
{
|
||
if (addr_hash.insert (target_call_site->pc).second)
|
||
{
|
||
/* Successfully entered TARGET_CALL_SITE. */
|
||
|
||
chain.push_back (target_call_site);
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Backtrack (without revisiting the originating call_site). Try the
|
||
callers's sibling; if there isn't any try the callers's callers's
|
||
sibling etc. */
|
||
|
||
target_call_site = NULL;
|
||
while (!chain.empty ())
|
||
{
|
||
call_site = chain.back ();
|
||
chain.pop_back ();
|
||
|
||
size_t removed = addr_hash.erase (call_site->pc);
|
||
gdb_assert (removed == 1);
|
||
|
||
target_call_site = call_site->tail_call_next;
|
||
if (target_call_site)
|
||
break;
|
||
}
|
||
}
|
||
while (target_call_site);
|
||
|
||
if (chain.empty ())
|
||
call_site = NULL;
|
||
else
|
||
call_site = chain.back ();
|
||
}
|
||
|
||
if (retval == NULL)
|
||
{
|
||
struct bound_minimal_symbol msym_caller, msym_callee;
|
||
|
||
msym_caller = lookup_minimal_symbol_by_pc (caller_pc);
|
||
msym_callee = lookup_minimal_symbol_by_pc (callee_pc);
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("There are no unambiguously determinable intermediate "
|
||
"callers or callees between caller function \"%s\" at %s "
|
||
"and callee function \"%s\" at %s"),
|
||
(msym_caller.minsym == NULL
|
||
? "???" : MSYMBOL_PRINT_NAME (msym_caller.minsym)),
|
||
paddress (gdbarch, caller_pc),
|
||
(msym_callee.minsym == NULL
|
||
? "???" : MSYMBOL_PRINT_NAME (msym_callee.minsym)),
|
||
paddress (gdbarch, callee_pc));
|
||
}
|
||
|
||
return retval.release ();
|
||
}
|
||
|
||
/* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
|
||
assumed frames between them use GDBARCH. If valid call_site_chain cannot be
|
||
constructed return NULL. Caller is responsible for xfree of the returned
|
||
result. */
|
||
|
||
struct call_site_chain *
|
||
call_site_find_chain (struct gdbarch *gdbarch, CORE_ADDR caller_pc,
|
||
CORE_ADDR callee_pc)
|
||
{
|
||
struct call_site_chain *retval = NULL;
|
||
|
||
TRY
|
||
{
|
||
retval = call_site_find_chain_1 (gdbarch, caller_pc, callee_pc);
|
||
}
|
||
CATCH (e, RETURN_MASK_ERROR)
|
||
{
|
||
if (e.error == NO_ENTRY_VALUE_ERROR)
|
||
{
|
||
if (entry_values_debug)
|
||
exception_print (gdb_stdout, e);
|
||
|
||
return NULL;
|
||
}
|
||
else
|
||
throw_exception (e);
|
||
}
|
||
END_CATCH
|
||
|
||
return retval;
|
||
}
|
||
|
||
/* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */
|
||
|
||
static int
|
||
call_site_parameter_matches (struct call_site_parameter *parameter,
|
||
enum call_site_parameter_kind kind,
|
||
union call_site_parameter_u kind_u)
|
||
{
|
||
if (kind == parameter->kind)
|
||
switch (kind)
|
||
{
|
||
case CALL_SITE_PARAMETER_DWARF_REG:
|
||
return kind_u.dwarf_reg == parameter->u.dwarf_reg;
|
||
case CALL_SITE_PARAMETER_FB_OFFSET:
|
||
return kind_u.fb_offset == parameter->u.fb_offset;
|
||
case CALL_SITE_PARAMETER_PARAM_OFFSET:
|
||
return kind_u.param_cu_off == parameter->u.param_cu_off;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* Fetch call_site_parameter from caller matching KIND and KIND_U.
|
||
FRAME is for callee.
|
||
|
||
Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
|
||
otherwise. */
|
||
|
||
static struct call_site_parameter *
|
||
dwarf_expr_reg_to_entry_parameter (struct frame_info *frame,
|
||
enum call_site_parameter_kind kind,
|
||
union call_site_parameter_u kind_u,
|
||
struct dwarf2_per_cu_data **per_cu_return)
|
||
{
|
||
CORE_ADDR func_addr, caller_pc;
|
||
struct gdbarch *gdbarch;
|
||
struct frame_info *caller_frame;
|
||
struct call_site *call_site;
|
||
int iparams;
|
||
/* Initialize it just to avoid a GCC false warning. */
|
||
struct call_site_parameter *parameter = NULL;
|
||
CORE_ADDR target_addr;
|
||
|
||
while (get_frame_type (frame) == INLINE_FRAME)
|
||
{
|
||
frame = get_prev_frame (frame);
|
||
gdb_assert (frame != NULL);
|
||
}
|
||
|
||
func_addr = get_frame_func (frame);
|
||
gdbarch = get_frame_arch (frame);
|
||
caller_frame = get_prev_frame (frame);
|
||
if (gdbarch != frame_unwind_arch (frame))
|
||
{
|
||
struct bound_minimal_symbol msym
|
||
= lookup_minimal_symbol_by_pc (func_addr);
|
||
struct gdbarch *caller_gdbarch = frame_unwind_arch (frame);
|
||
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DW_OP_entry_value resolving callee gdbarch %s "
|
||
"(of %s (%s)) does not match caller gdbarch %s"),
|
||
gdbarch_bfd_arch_info (gdbarch)->printable_name,
|
||
paddress (gdbarch, func_addr),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)),
|
||
gdbarch_bfd_arch_info (caller_gdbarch)->printable_name);
|
||
}
|
||
|
||
if (caller_frame == NULL)
|
||
{
|
||
struct bound_minimal_symbol msym
|
||
= lookup_minimal_symbol_by_pc (func_addr);
|
||
|
||
throw_error (NO_ENTRY_VALUE_ERROR, _("DW_OP_entry_value resolving "
|
||
"requires caller of %s (%s)"),
|
||
paddress (gdbarch, func_addr),
|
||
(msym.minsym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (msym.minsym)));
|
||
}
|
||
caller_pc = get_frame_pc (caller_frame);
|
||
call_site = call_site_for_pc (gdbarch, caller_pc);
|
||
|
||
target_addr = call_site_to_target_addr (gdbarch, call_site, caller_frame);
|
||
if (target_addr != func_addr)
|
||
{
|
||
struct minimal_symbol *target_msym, *func_msym;
|
||
|
||
target_msym = lookup_minimal_symbol_by_pc (target_addr).minsym;
|
||
func_msym = lookup_minimal_symbol_by_pc (func_addr).minsym;
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DW_OP_entry_value resolving expects callee %s at %s "
|
||
"but the called frame is for %s at %s"),
|
||
(target_msym == NULL ? "???"
|
||
: MSYMBOL_PRINT_NAME (target_msym)),
|
||
paddress (gdbarch, target_addr),
|
||
func_msym == NULL ? "???" : MSYMBOL_PRINT_NAME (func_msym),
|
||
paddress (gdbarch, func_addr));
|
||
}
|
||
|
||
/* No entry value based parameters would be reliable if this function can
|
||
call itself via tail calls. */
|
||
func_verify_no_selftailcall (gdbarch, func_addr);
|
||
|
||
for (iparams = 0; iparams < call_site->parameter_count; iparams++)
|
||
{
|
||
parameter = &call_site->parameter[iparams];
|
||
if (call_site_parameter_matches (parameter, kind, kind_u))
|
||
break;
|
||
}
|
||
if (iparams == call_site->parameter_count)
|
||
{
|
||
struct minimal_symbol *msym
|
||
= lookup_minimal_symbol_by_pc (caller_pc).minsym;
|
||
|
||
/* DW_TAG_call_site_parameter will be missing just if GCC could not
|
||
determine its value. */
|
||
throw_error (NO_ENTRY_VALUE_ERROR, _("Cannot find matching parameter "
|
||
"at DW_TAG_call_site %s at %s"),
|
||
paddress (gdbarch, caller_pc),
|
||
msym == NULL ? "???" : MSYMBOL_PRINT_NAME (msym));
|
||
}
|
||
|
||
*per_cu_return = call_site->per_cu;
|
||
return parameter;
|
||
}
|
||
|
||
/* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return
|
||
the normal DW_AT_call_value block. Otherwise return the
|
||
DW_AT_call_data_value (dereferenced) block.
|
||
|
||
TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned
|
||
struct value.
|
||
|
||
Function always returns non-NULL, non-optimized out value. It throws
|
||
NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */
|
||
|
||
static struct value *
|
||
dwarf_entry_parameter_to_value (struct call_site_parameter *parameter,
|
||
CORE_ADDR deref_size, struct type *type,
|
||
struct frame_info *caller_frame,
|
||
struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
const gdb_byte *data_src;
|
||
gdb_byte *data;
|
||
size_t size;
|
||
|
||
data_src = deref_size == -1 ? parameter->value : parameter->data_value;
|
||
size = deref_size == -1 ? parameter->value_size : parameter->data_value_size;
|
||
|
||
/* DEREF_SIZE size is not verified here. */
|
||
if (data_src == NULL)
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("Cannot resolve DW_AT_call_data_value"));
|
||
|
||
/* DW_AT_call_value is a DWARF expression, not a DWARF
|
||
location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
|
||
DWARF block. */
|
||
data = (gdb_byte *) alloca (size + 1);
|
||
memcpy (data, data_src, size);
|
||
data[size] = DW_OP_stack_value;
|
||
|
||
return dwarf2_evaluate_loc_desc (type, caller_frame, data, size + 1, per_cu);
|
||
}
|
||
|
||
/* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
|
||
the indirect method on it, that is use its stored target value, the sole
|
||
purpose of entry_data_value_funcs.. */
|
||
|
||
static struct value *
|
||
entry_data_value_coerce_ref (const struct value *value)
|
||
{
|
||
struct type *checked_type = check_typedef (value_type (value));
|
||
struct value *target_val;
|
||
|
||
if (!TYPE_IS_REFERENCE (checked_type))
|
||
return NULL;
|
||
|
||
target_val = (struct value *) value_computed_closure (value);
|
||
value_incref (target_val);
|
||
return target_val;
|
||
}
|
||
|
||
/* Implement copy_closure. */
|
||
|
||
static void *
|
||
entry_data_value_copy_closure (const struct value *v)
|
||
{
|
||
struct value *target_val = (struct value *) value_computed_closure (v);
|
||
|
||
value_incref (target_val);
|
||
return target_val;
|
||
}
|
||
|
||
/* Implement free_closure. */
|
||
|
||
static void
|
||
entry_data_value_free_closure (struct value *v)
|
||
{
|
||
struct value *target_val = (struct value *) value_computed_closure (v);
|
||
|
||
value_free (target_val);
|
||
}
|
||
|
||
/* Vector for methods for an entry value reference where the referenced value
|
||
is stored in the caller. On the first dereference use
|
||
DW_AT_call_data_value in the caller. */
|
||
|
||
static const struct lval_funcs entry_data_value_funcs =
|
||
{
|
||
NULL, /* read */
|
||
NULL, /* write */
|
||
NULL, /* indirect */
|
||
entry_data_value_coerce_ref,
|
||
NULL, /* check_synthetic_pointer */
|
||
entry_data_value_copy_closure,
|
||
entry_data_value_free_closure
|
||
};
|
||
|
||
/* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U
|
||
are used to match DW_AT_location at the caller's
|
||
DW_TAG_call_site_parameter.
|
||
|
||
Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
|
||
cannot resolve the parameter for any reason. */
|
||
|
||
static struct value *
|
||
value_of_dwarf_reg_entry (struct type *type, struct frame_info *frame,
|
||
enum call_site_parameter_kind kind,
|
||
union call_site_parameter_u kind_u)
|
||
{
|
||
struct type *checked_type = check_typedef (type);
|
||
struct type *target_type = TYPE_TARGET_TYPE (checked_type);
|
||
struct frame_info *caller_frame = get_prev_frame (frame);
|
||
struct value *outer_val, *target_val, *val;
|
||
struct call_site_parameter *parameter;
|
||
struct dwarf2_per_cu_data *caller_per_cu;
|
||
|
||
parameter = dwarf_expr_reg_to_entry_parameter (frame, kind, kind_u,
|
||
&caller_per_cu);
|
||
|
||
outer_val = dwarf_entry_parameter_to_value (parameter, -1 /* deref_size */,
|
||
type, caller_frame,
|
||
caller_per_cu);
|
||
|
||
/* Check if DW_AT_call_data_value cannot be used. If it should be
|
||
used and it is not available do not fall back to OUTER_VAL - dereferencing
|
||
TYPE_CODE_REF with non-entry data value would give current value - not the
|
||
entry value. */
|
||
|
||
if (!TYPE_IS_REFERENCE (checked_type)
|
||
|| TYPE_TARGET_TYPE (checked_type) == NULL)
|
||
return outer_val;
|
||
|
||
target_val = dwarf_entry_parameter_to_value (parameter,
|
||
TYPE_LENGTH (target_type),
|
||
target_type, caller_frame,
|
||
caller_per_cu);
|
||
|
||
release_value (target_val);
|
||
val = allocate_computed_value (type, &entry_data_value_funcs,
|
||
target_val /* closure */);
|
||
|
||
/* Copy the referencing pointer to the new computed value. */
|
||
memcpy (value_contents_raw (val), value_contents_raw (outer_val),
|
||
TYPE_LENGTH (checked_type));
|
||
set_value_lazy (val, 0);
|
||
|
||
return val;
|
||
}
|
||
|
||
/* Read parameter of TYPE at (callee) FRAME's function entry. DATA and
|
||
SIZE are DWARF block used to match DW_AT_location at the caller's
|
||
DW_TAG_call_site_parameter.
|
||
|
||
Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
|
||
cannot resolve the parameter for any reason. */
|
||
|
||
static struct value *
|
||
value_of_dwarf_block_entry (struct type *type, struct frame_info *frame,
|
||
const gdb_byte *block, size_t block_len)
|
||
{
|
||
union call_site_parameter_u kind_u;
|
||
|
||
kind_u.dwarf_reg = dwarf_block_to_dwarf_reg (block, block + block_len);
|
||
if (kind_u.dwarf_reg != -1)
|
||
return value_of_dwarf_reg_entry (type, frame, CALL_SITE_PARAMETER_DWARF_REG,
|
||
kind_u);
|
||
|
||
if (dwarf_block_to_fb_offset (block, block + block_len, &kind_u.fb_offset))
|
||
return value_of_dwarf_reg_entry (type, frame, CALL_SITE_PARAMETER_FB_OFFSET,
|
||
kind_u);
|
||
|
||
/* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message
|
||
suppressed during normal operation. The expression can be arbitrary if
|
||
there is no caller-callee entry value binding expected. */
|
||
throw_error (NO_ENTRY_VALUE_ERROR,
|
||
_("DWARF-2 expression error: DW_OP_entry_value is supported "
|
||
"only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
|
||
}
|
||
|
||
struct piece_closure
|
||
{
|
||
/* Reference count. */
|
||
int refc = 0;
|
||
|
||
/* The CU from which this closure's expression came. */
|
||
struct dwarf2_per_cu_data *per_cu = NULL;
|
||
|
||
/* The pieces describing this variable. */
|
||
std::vector<dwarf_expr_piece> pieces;
|
||
|
||
/* Frame ID of frame to which a register value is relative, used
|
||
only by DWARF_VALUE_REGISTER. */
|
||
struct frame_id frame_id;
|
||
};
|
||
|
||
/* Allocate a closure for a value formed from separately-described
|
||
PIECES. */
|
||
|
||
static struct piece_closure *
|
||
allocate_piece_closure (struct dwarf2_per_cu_data *per_cu,
|
||
std::vector<dwarf_expr_piece> &&pieces,
|
||
struct frame_info *frame)
|
||
{
|
||
struct piece_closure *c = new piece_closure;
|
||
|
||
c->refc = 1;
|
||
c->per_cu = per_cu;
|
||
c->pieces = std::move (pieces);
|
||
if (frame == NULL)
|
||
c->frame_id = null_frame_id;
|
||
else
|
||
c->frame_id = get_frame_id (frame);
|
||
|
||
for (dwarf_expr_piece &piece : c->pieces)
|
||
if (piece.location == DWARF_VALUE_STACK)
|
||
value_incref (piece.v.value);
|
||
|
||
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. */
|
||
|
||
static size_t
|
||
bits_to_bytes (ULONGEST start, ULONGEST n_bits)
|
||
{
|
||
return (start % 8 + n_bits + 7) / 8;
|
||
}
|
||
|
||
/* Read or write a pieced value V. If FROM != NULL, operate in "write
|
||
mode": copy FROM into the pieces comprising V. If FROM == NULL,
|
||
operate in "read mode": fetch the contents of the (lazy) value V by
|
||
composing it from its pieces. */
|
||
|
||
static void
|
||
rw_pieced_value (struct value *v, struct value *from)
|
||
{
|
||
int i;
|
||
LONGEST offset = 0, max_offset;
|
||
ULONGEST bits_to_skip;
|
||
gdb_byte *v_contents;
|
||
const gdb_byte *from_contents;
|
||
struct piece_closure *c
|
||
= (struct piece_closure *) value_computed_closure (v);
|
||
gdb::byte_vector buffer;
|
||
int bits_big_endian
|
||
= gdbarch_bits_big_endian (get_type_arch (value_type (v)));
|
||
|
||
if (from != NULL)
|
||
{
|
||
from_contents = value_contents (from);
|
||
v_contents = NULL;
|
||
}
|
||
else
|
||
{
|
||
if (value_type (v) != value_enclosing_type (v))
|
||
internal_error (__FILE__, __LINE__,
|
||
_("Should not be able to create a lazy value with "
|
||
"an enclosing type"));
|
||
v_contents = value_contents_raw (v);
|
||
from_contents = NULL;
|
||
}
|
||
|
||
bits_to_skip = 8 * value_offset (v);
|
||
if (value_bitsize (v))
|
||
{
|
||
bits_to_skip += (8 * value_offset (value_parent (v))
|
||
+ value_bitpos (v));
|
||
if (from != NULL
|
||
&& (gdbarch_byte_order (get_type_arch (value_type (from)))
|
||
== BFD_ENDIAN_BIG))
|
||
{
|
||
/* Use the least significant bits of FROM. */
|
||
max_offset = 8 * TYPE_LENGTH (value_type (from));
|
||
offset = max_offset - value_bitsize (v);
|
||
}
|
||
else
|
||
max_offset = value_bitsize (v);
|
||
}
|
||
else
|
||
max_offset = 8 * TYPE_LENGTH (value_type (v));
|
||
|
||
/* Advance to the first non-skipped piece. */
|
||
for (i = 0; i < c->pieces.size () && bits_to_skip >= c->pieces[i].size; i++)
|
||
bits_to_skip -= c->pieces[i].size;
|
||
|
||
for (; i < c->pieces.size () && offset < max_offset; i++)
|
||
{
|
||
struct dwarf_expr_piece *p = &c->pieces[i];
|
||
size_t this_size_bits, this_size;
|
||
|
||
this_size_bits = p->size - bits_to_skip;
|
||
if (this_size_bits > max_offset - offset)
|
||
this_size_bits = max_offset - offset;
|
||
|
||
switch (p->location)
|
||
{
|
||
case DWARF_VALUE_REGISTER:
|
||
{
|
||
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;
|
||
|
||
if (gdbarch_byte_order (arch) == BFD_ENDIAN_BIG
|
||
&& p->offset + p->size < reg_bits)
|
||
{
|
||
/* Big-endian, and we want less than full size. */
|
||
bits_to_skip += reg_bits - (p->offset + p->size);
|
||
}
|
||
else
|
||
bits_to_skip += p->offset;
|
||
|
||
this_size = bits_to_bytes (bits_to_skip, this_size_bits);
|
||
buffer.resize (this_size);
|
||
|
||
if (from == NULL)
|
||
{
|
||
/* Read mode. */
|
||
if (!get_frame_register_bytes (frame, gdb_regnum,
|
||
bits_to_skip / 8,
|
||
this_size, buffer.data (),
|
||
&optim, &unavail))
|
||
{
|
||
if (optim)
|
||
mark_value_bits_optimized_out (v, offset,
|
||
this_size_bits);
|
||
if (unavail)
|
||
mark_value_bits_unavailable (v, offset,
|
||
this_size_bits);
|
||
break;
|
||
}
|
||
|
||
copy_bitwise (v_contents, offset,
|
||
buffer.data (), bits_to_skip % 8,
|
||
this_size_bits, bits_big_endian);
|
||
}
|
||
else
|
||
{
|
||
/* Write mode. */
|
||
if (bits_to_skip % 8 != 0 || this_size_bits % 8 != 0)
|
||
{
|
||
/* Data is copied non-byte-aligned into the register.
|
||
Need some bits from original register value. */
|
||
get_frame_register_bytes (frame, gdb_regnum,
|
||
bits_to_skip / 8,
|
||
this_size, buffer.data (),
|
||
&optim, &unavail);
|
||
if (optim)
|
||
throw_error (OPTIMIZED_OUT_ERROR,
|
||
_("Can't do read-modify-write to "
|
||
"update bitfield; containing word "
|
||
"has been optimized out"));
|
||
if (unavail)
|
||
throw_error (NOT_AVAILABLE_ERROR,
|
||
_("Can't do read-modify-write to "
|
||
"update bitfield; containing word "
|
||
"is unavailable"));
|
||
}
|
||
|
||
copy_bitwise (buffer.data (), bits_to_skip % 8,
|
||
from_contents, offset,
|
||
this_size_bits, bits_big_endian);
|
||
put_frame_register_bytes (frame, gdb_regnum,
|
||
bits_to_skip / 8,
|
||
this_size, buffer.data ());
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_MEMORY:
|
||
{
|
||
bits_to_skip += p->offset;
|
||
|
||
CORE_ADDR start_addr = p->v.mem.addr + bits_to_skip / 8;
|
||
|
||
if (bits_to_skip % 8 == 0 && this_size_bits % 8 == 0
|
||
&& offset % 8 == 0)
|
||
{
|
||
/* Everything is byte-aligned; no buffer needed. */
|
||
if (from != NULL)
|
||
write_memory_with_notification (start_addr,
|
||
(from_contents
|
||
+ offset / 8),
|
||
this_size_bits / 8);
|
||
else
|
||
read_value_memory (v, offset,
|
||
p->v.mem.in_stack_memory,
|
||
p->v.mem.addr + bits_to_skip / 8,
|
||
v_contents + offset / 8,
|
||
this_size_bits / 8);
|
||
break;
|
||
}
|
||
|
||
this_size = bits_to_bytes (bits_to_skip, this_size_bits);
|
||
buffer.resize (this_size);
|
||
|
||
if (from == NULL)
|
||
{
|
||
/* Read mode. */
|
||
read_value_memory (v, offset,
|
||
p->v.mem.in_stack_memory,
|
||
p->v.mem.addr + bits_to_skip / 8,
|
||
buffer.data (), this_size);
|
||
copy_bitwise (v_contents, offset,
|
||
buffer.data (), bits_to_skip % 8,
|
||
this_size_bits, bits_big_endian);
|
||
}
|
||
else
|
||
{
|
||
/* Write mode. */
|
||
if (bits_to_skip % 8 != 0 || this_size_bits % 8 != 0)
|
||
{
|
||
if (this_size <= 8)
|
||
{
|
||
/* Perform a single read for small sizes. */
|
||
read_memory (start_addr, buffer.data (),
|
||
this_size);
|
||
}
|
||
else
|
||
{
|
||
/* Only the first and last bytes can possibly have
|
||
any bits reused. */
|
||
read_memory (start_addr, buffer.data (), 1);
|
||
read_memory (start_addr + this_size - 1,
|
||
&buffer[this_size - 1], 1);
|
||
}
|
||
}
|
||
|
||
copy_bitwise (buffer.data (), bits_to_skip % 8,
|
||
from_contents, offset,
|
||
this_size_bits, bits_big_endian);
|
||
write_memory_with_notification (start_addr,
|
||
buffer.data (),
|
||
this_size);
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_STACK:
|
||
{
|
||
if (from != NULL)
|
||
{
|
||
mark_value_bits_optimized_out (v, offset, this_size_bits);
|
||
break;
|
||
}
|
||
|
||
struct objfile *objfile = dwarf2_per_cu_objfile (c->per_cu);
|
||
struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile);
|
||
ULONGEST stack_value_size_bits
|
||
= 8 * TYPE_LENGTH (value_type (p->v.value));
|
||
|
||
/* Use zeroes if piece reaches beyond stack value. */
|
||
if (p->offset + p->size > stack_value_size_bits)
|
||
break;
|
||
|
||
/* Piece is anchored at least significant bit end. */
|
||
if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG)
|
||
bits_to_skip += stack_value_size_bits - p->offset - p->size;
|
||
else
|
||
bits_to_skip += p->offset;
|
||
|
||
copy_bitwise (v_contents, offset,
|
||
value_contents_all (p->v.value),
|
||
bits_to_skip,
|
||
this_size_bits, bits_big_endian);
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_LITERAL:
|
||
{
|
||
if (from != NULL)
|
||
{
|
||
mark_value_bits_optimized_out (v, offset, this_size_bits);
|
||
break;
|
||
}
|
||
|
||
ULONGEST literal_size_bits = 8 * p->v.literal.length;
|
||
size_t n = this_size_bits;
|
||
|
||
/* Cut off at the end of the implicit value. */
|
||
bits_to_skip += p->offset;
|
||
if (bits_to_skip >= literal_size_bits)
|
||
break;
|
||
if (n > literal_size_bits - bits_to_skip)
|
||
n = literal_size_bits - bits_to_skip;
|
||
|
||
copy_bitwise (v_contents, offset,
|
||
p->v.literal.data, bits_to_skip,
|
||
n, bits_big_endian);
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_IMPLICIT_POINTER:
|
||
if (from != NULL)
|
||
{
|
||
mark_value_bits_optimized_out (v, offset, this_size_bits);
|
||
break;
|
||
}
|
||
|
||
/* These bits show up as zeros -- but do not cause the value to
|
||
be considered optimized-out. */
|
||
break;
|
||
|
||
case DWARF_VALUE_OPTIMIZED_OUT:
|
||
mark_value_bits_optimized_out (v, offset, this_size_bits);
|
||
break;
|
||
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("invalid location type"));
|
||
}
|
||
|
||
offset += this_size_bits;
|
||
bits_to_skip = 0;
|
||
}
|
||
}
|
||
|
||
|
||
static void
|
||
read_pieced_value (struct value *v)
|
||
{
|
||
rw_pieced_value (v, NULL);
|
||
}
|
||
|
||
static void
|
||
write_pieced_value (struct value *to, struct value *from)
|
||
{
|
||
rw_pieced_value (to, from);
|
||
}
|
||
|
||
/* An implementation of an lval_funcs method to see whether a value is
|
||
a synthetic pointer. */
|
||
|
||
static int
|
||
check_pieced_synthetic_pointer (const struct value *value, LONGEST bit_offset,
|
||
int bit_length)
|
||
{
|
||
struct piece_closure *c
|
||
= (struct piece_closure *) value_computed_closure (value);
|
||
int i;
|
||
|
||
bit_offset += 8 * value_offset (value);
|
||
if (value_bitsize (value))
|
||
bit_offset += value_bitpos (value);
|
||
|
||
for (i = 0; i < c->pieces.size () && bit_length > 0; i++)
|
||
{
|
||
struct dwarf_expr_piece *p = &c->pieces[i];
|
||
size_t this_size_bits = p->size;
|
||
|
||
if (bit_offset > 0)
|
||
{
|
||
if (bit_offset >= this_size_bits)
|
||
{
|
||
bit_offset -= this_size_bits;
|
||
continue;
|
||
}
|
||
|
||
bit_length -= this_size_bits - bit_offset;
|
||
bit_offset = 0;
|
||
}
|
||
else
|
||
bit_length -= this_size_bits;
|
||
|
||
if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
|
||
return 0;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* A wrapper function for get_frame_address_in_block. */
|
||
|
||
static CORE_ADDR
|
||
get_frame_address_in_block_wrapper (void *baton)
|
||
{
|
||
return get_frame_address_in_block ((struct frame_info *) baton);
|
||
}
|
||
|
||
/* Fetch a DW_AT_const_value through a synthetic pointer. */
|
||
|
||
static struct value *
|
||
fetch_const_value_from_synthetic_pointer (sect_offset die, LONGEST byte_offset,
|
||
struct dwarf2_per_cu_data *per_cu,
|
||
struct type *type)
|
||
{
|
||
struct value *result = NULL;
|
||
const gdb_byte *bytes;
|
||
LONGEST len;
|
||
|
||
auto_obstack temp_obstack;
|
||
bytes = dwarf2_fetch_constant_bytes (die, per_cu, &temp_obstack, &len);
|
||
|
||
if (bytes != NULL)
|
||
{
|
||
if (byte_offset >= 0
|
||
&& byte_offset + TYPE_LENGTH (TYPE_TARGET_TYPE (type)) <= len)
|
||
{
|
||
bytes += byte_offset;
|
||
result = value_from_contents (TYPE_TARGET_TYPE (type), bytes);
|
||
}
|
||
else
|
||
invalid_synthetic_pointer ();
|
||
}
|
||
else
|
||
result = allocate_optimized_out_value (TYPE_TARGET_TYPE (type));
|
||
|
||
return result;
|
||
}
|
||
|
||
/* Fetch the value pointed to by a synthetic pointer. */
|
||
|
||
static struct value *
|
||
indirect_synthetic_pointer (sect_offset die, LONGEST byte_offset,
|
||
struct dwarf2_per_cu_data *per_cu,
|
||
struct frame_info *frame, struct type *type)
|
||
{
|
||
/* Fetch the location expression of the DIE we're pointing to. */
|
||
struct dwarf2_locexpr_baton baton
|
||
= dwarf2_fetch_die_loc_sect_off (die, per_cu,
|
||
get_frame_address_in_block_wrapper, frame);
|
||
|
||
/* Get type of pointed-to DIE. */
|
||
struct type *orig_type = dwarf2_fetch_die_type_sect_off (die, per_cu);
|
||
if (orig_type == NULL)
|
||
invalid_synthetic_pointer ();
|
||
|
||
/* If pointed-to DIE has a DW_AT_location, evaluate it and return the
|
||
resulting value. Otherwise, it may have a DW_AT_const_value instead,
|
||
or it may've been optimized out. */
|
||
if (baton.data != NULL)
|
||
return dwarf2_evaluate_loc_desc_full (orig_type, frame, baton.data,
|
||
baton.size, baton.per_cu,
|
||
TYPE_TARGET_TYPE (type),
|
||
byte_offset);
|
||
else
|
||
return fetch_const_value_from_synthetic_pointer (die, byte_offset, per_cu,
|
||
type);
|
||
}
|
||
|
||
/* An implementation of an lval_funcs method to indirect through a
|
||
pointer. This handles the synthetic pointer case when needed. */
|
||
|
||
static struct value *
|
||
indirect_pieced_value (struct value *value)
|
||
{
|
||
struct piece_closure *c
|
||
= (struct piece_closure *) value_computed_closure (value);
|
||
struct type *type;
|
||
struct frame_info *frame;
|
||
int i, bit_length;
|
||
LONGEST bit_offset;
|
||
struct dwarf_expr_piece *piece = NULL;
|
||
LONGEST byte_offset;
|
||
enum bfd_endian byte_order;
|
||
|
||
type = check_typedef (value_type (value));
|
||
if (TYPE_CODE (type) != TYPE_CODE_PTR)
|
||
return NULL;
|
||
|
||
bit_length = 8 * TYPE_LENGTH (type);
|
||
bit_offset = 8 * value_offset (value);
|
||
if (value_bitsize (value))
|
||
bit_offset += value_bitpos (value);
|
||
|
||
for (i = 0; i < c->pieces.size () && bit_length > 0; i++)
|
||
{
|
||
struct dwarf_expr_piece *p = &c->pieces[i];
|
||
size_t this_size_bits = p->size;
|
||
|
||
if (bit_offset > 0)
|
||
{
|
||
if (bit_offset >= this_size_bits)
|
||
{
|
||
bit_offset -= this_size_bits;
|
||
continue;
|
||
}
|
||
|
||
bit_length -= this_size_bits - bit_offset;
|
||
bit_offset = 0;
|
||
}
|
||
else
|
||
bit_length -= this_size_bits;
|
||
|
||
if (p->location != DWARF_VALUE_IMPLICIT_POINTER)
|
||
return NULL;
|
||
|
||
if (bit_length != 0)
|
||
error (_("Invalid use of DW_OP_implicit_pointer"));
|
||
|
||
piece = p;
|
||
break;
|
||
}
|
||
|
||
gdb_assert (piece != NULL);
|
||
frame = get_selected_frame (_("No frame selected."));
|
||
|
||
/* This is an offset requested by GDB, such as value subscripts.
|
||
However, due to how synthetic pointers are implemented, this is
|
||
always presented to us as a pointer type. This means we have to
|
||
sign-extend it manually as appropriate. Use raw
|
||
extract_signed_integer directly rather than value_as_address and
|
||
sign extend afterwards on architectures that would need it
|
||
(mostly everywhere except MIPS, which has signed addresses) as
|
||
the later would go through gdbarch_pointer_to_address and thus
|
||
return a CORE_ADDR with high bits set on architectures that
|
||
encode address spaces and other things in CORE_ADDR. */
|
||
byte_order = gdbarch_byte_order (get_frame_arch (frame));
|
||
byte_offset = extract_signed_integer (value_contents (value),
|
||
TYPE_LENGTH (type), byte_order);
|
||
byte_offset += piece->v.ptr.offset;
|
||
|
||
return indirect_synthetic_pointer (piece->v.ptr.die_sect_off,
|
||
byte_offset, c->per_cu,
|
||
frame, type);
|
||
}
|
||
|
||
/* Implementation of the coerce_ref method of lval_funcs for synthetic C++
|
||
references. */
|
||
|
||
static struct value *
|
||
coerce_pieced_ref (const struct value *value)
|
||
{
|
||
struct type *type = check_typedef (value_type (value));
|
||
|
||
if (value_bits_synthetic_pointer (value, value_embedded_offset (value),
|
||
TARGET_CHAR_BIT * TYPE_LENGTH (type)))
|
||
{
|
||
const struct piece_closure *closure
|
||
= (struct piece_closure *) value_computed_closure (value);
|
||
struct frame_info *frame
|
||
= get_selected_frame (_("No frame selected."));
|
||
|
||
/* gdb represents synthetic pointers as pieced values with a single
|
||
piece. */
|
||
gdb_assert (closure != NULL);
|
||
gdb_assert (closure->pieces.size () == 1);
|
||
|
||
return indirect_synthetic_pointer
|
||
(closure->pieces[0].v.ptr.die_sect_off,
|
||
closure->pieces[0].v.ptr.offset,
|
||
closure->per_cu, frame, type);
|
||
}
|
||
else
|
||
{
|
||
/* Else: not a synthetic reference; do nothing. */
|
||
return NULL;
|
||
}
|
||
}
|
||
|
||
static void *
|
||
copy_pieced_value_closure (const struct value *v)
|
||
{
|
||
struct piece_closure *c
|
||
= (struct piece_closure *) value_computed_closure (v);
|
||
|
||
++c->refc;
|
||
return c;
|
||
}
|
||
|
||
static void
|
||
free_pieced_value_closure (struct value *v)
|
||
{
|
||
struct piece_closure *c
|
||
= (struct piece_closure *) value_computed_closure (v);
|
||
|
||
--c->refc;
|
||
if (c->refc == 0)
|
||
{
|
||
for (dwarf_expr_piece &p : c->pieces)
|
||
if (p.location == DWARF_VALUE_STACK)
|
||
value_free (p.v.value);
|
||
|
||
delete c;
|
||
}
|
||
}
|
||
|
||
/* Functions for accessing a variable described by DW_OP_piece. */
|
||
static const struct lval_funcs pieced_value_funcs = {
|
||
read_pieced_value,
|
||
write_pieced_value,
|
||
indirect_pieced_value,
|
||
coerce_pieced_ref,
|
||
check_pieced_synthetic_pointer,
|
||
copy_pieced_value_closure,
|
||
free_pieced_value_closure
|
||
};
|
||
|
||
/* Evaluate a location description, starting at DATA and with length
|
||
SIZE, to find the current location of variable of TYPE in the
|
||
context of FRAME. If SUBOBJ_TYPE is non-NULL, return instead the
|
||
location of the subobject of type SUBOBJ_TYPE at byte offset
|
||
SUBOBJ_BYTE_OFFSET within the variable of type TYPE. */
|
||
|
||
static struct value *
|
||
dwarf2_evaluate_loc_desc_full (struct type *type, struct frame_info *frame,
|
||
const gdb_byte *data, size_t size,
|
||
struct dwarf2_per_cu_data *per_cu,
|
||
struct type *subobj_type,
|
||
LONGEST subobj_byte_offset)
|
||
{
|
||
struct value *retval;
|
||
struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
|
||
|
||
if (subobj_type == NULL)
|
||
{
|
||
subobj_type = type;
|
||
subobj_byte_offset = 0;
|
||
}
|
||
else if (subobj_byte_offset < 0)
|
||
invalid_synthetic_pointer ();
|
||
|
||
if (size == 0)
|
||
return allocate_optimized_out_value (subobj_type);
|
||
|
||
dwarf_evaluate_loc_desc ctx;
|
||
ctx.frame = frame;
|
||
ctx.per_cu = per_cu;
|
||
ctx.obj_address = 0;
|
||
|
||
scoped_value_mark free_values;
|
||
|
||
ctx.gdbarch = get_objfile_arch (objfile);
|
||
ctx.addr_size = dwarf2_per_cu_addr_size (per_cu);
|
||
ctx.ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu);
|
||
ctx.offset = dwarf2_per_cu_text_offset (per_cu);
|
||
|
||
TRY
|
||
{
|
||
ctx.eval (data, size);
|
||
}
|
||
CATCH (ex, RETURN_MASK_ERROR)
|
||
{
|
||
if (ex.error == NOT_AVAILABLE_ERROR)
|
||
{
|
||
free_values.free_to_mark ();
|
||
retval = allocate_value (subobj_type);
|
||
mark_value_bytes_unavailable (retval, 0,
|
||
TYPE_LENGTH (subobj_type));
|
||
return retval;
|
||
}
|
||
else if (ex.error == NO_ENTRY_VALUE_ERROR)
|
||
{
|
||
if (entry_values_debug)
|
||
exception_print (gdb_stdout, ex);
|
||
free_values.free_to_mark ();
|
||
return allocate_optimized_out_value (subobj_type);
|
||
}
|
||
else
|
||
throw_exception (ex);
|
||
}
|
||
END_CATCH
|
||
|
||
if (ctx.pieces.size () > 0)
|
||
{
|
||
struct piece_closure *c;
|
||
ULONGEST bit_size = 0;
|
||
|
||
for (dwarf_expr_piece &piece : ctx.pieces)
|
||
bit_size += piece.size;
|
||
/* Complain if the expression is larger than the size of the
|
||
outer type. */
|
||
if (bit_size > 8 * TYPE_LENGTH (type))
|
||
invalid_synthetic_pointer ();
|
||
|
||
c = allocate_piece_closure (per_cu, std::move (ctx.pieces), frame);
|
||
/* We must clean up the value chain after creating the piece
|
||
closure but before allocating the result. */
|
||
free_values.free_to_mark ();
|
||
retval = allocate_computed_value (subobj_type,
|
||
&pieced_value_funcs, c);
|
||
set_value_offset (retval, subobj_byte_offset);
|
||
}
|
||
else
|
||
{
|
||
switch (ctx.location)
|
||
{
|
||
case DWARF_VALUE_REGISTER:
|
||
{
|
||
struct gdbarch *arch = get_frame_arch (frame);
|
||
int dwarf_regnum
|
||
= longest_to_int (value_as_long (ctx.fetch (0)));
|
||
int gdb_regnum = dwarf_reg_to_regnum_or_error (arch, dwarf_regnum);
|
||
|
||
if (subobj_byte_offset != 0)
|
||
error (_("cannot use offset on synthetic pointer to register"));
|
||
free_values.free_to_mark ();
|
||
retval = value_from_register (subobj_type, gdb_regnum, frame);
|
||
if (value_optimized_out (retval))
|
||
{
|
||
struct value *tmp;
|
||
|
||
/* This means the register has undefined value / was
|
||
not saved. As we're computing the location of some
|
||
variable etc. in the program, not a value for
|
||
inspecting a register ($pc, $sp, etc.), return a
|
||
generic optimized out value instead, so that we show
|
||
<optimized out> instead of <not saved>. */
|
||
tmp = allocate_value (subobj_type);
|
||
value_contents_copy (tmp, 0, retval, 0,
|
||
TYPE_LENGTH (subobj_type));
|
||
retval = tmp;
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_MEMORY:
|
||
{
|
||
struct type *ptr_type;
|
||
CORE_ADDR address = ctx.fetch_address (0);
|
||
bool in_stack_memory = ctx.fetch_in_stack_memory (0);
|
||
|
||
/* DW_OP_deref_size (and possibly other operations too) may
|
||
create a pointer instead of an address. Ideally, the
|
||
pointer to address conversion would be performed as part
|
||
of those operations, but the type of the object to
|
||
which the address refers is not known at the time of
|
||
the operation. Therefore, we do the conversion here
|
||
since the type is readily available. */
|
||
|
||
switch (TYPE_CODE (subobj_type))
|
||
{
|
||
case TYPE_CODE_FUNC:
|
||
case TYPE_CODE_METHOD:
|
||
ptr_type = builtin_type (ctx.gdbarch)->builtin_func_ptr;
|
||
break;
|
||
default:
|
||
ptr_type = builtin_type (ctx.gdbarch)->builtin_data_ptr;
|
||
break;
|
||
}
|
||
address = value_as_address (value_from_pointer (ptr_type, address));
|
||
|
||
free_values.free_to_mark ();
|
||
retval = value_at_lazy (subobj_type,
|
||
address + subobj_byte_offset);
|
||
if (in_stack_memory)
|
||
set_value_stack (retval, 1);
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_STACK:
|
||
{
|
||
struct value *value = ctx.fetch (0);
|
||
size_t n = TYPE_LENGTH (value_type (value));
|
||
size_t len = TYPE_LENGTH (subobj_type);
|
||
size_t max = TYPE_LENGTH (type);
|
||
struct gdbarch *objfile_gdbarch = get_objfile_arch (objfile);
|
||
|
||
if (subobj_byte_offset + len > max)
|
||
invalid_synthetic_pointer ();
|
||
|
||
/* Preserve VALUE because we are going to free values back
|
||
to the mark, but we still need the value contents
|
||
below. */
|
||
value_incref (value);
|
||
free_values.free_to_mark ();
|
||
gdb_value_up value_holder (value);
|
||
|
||
retval = allocate_value (subobj_type);
|
||
|
||
/* The given offset is relative to the actual object. */
|
||
if (gdbarch_byte_order (objfile_gdbarch) == BFD_ENDIAN_BIG)
|
||
subobj_byte_offset += n - max;
|
||
|
||
memcpy (value_contents_raw (retval),
|
||
value_contents_all (value) + subobj_byte_offset, len);
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_LITERAL:
|
||
{
|
||
bfd_byte *contents;
|
||
size_t n = TYPE_LENGTH (subobj_type);
|
||
|
||
if (subobj_byte_offset + n > ctx.len)
|
||
invalid_synthetic_pointer ();
|
||
|
||
free_values.free_to_mark ();
|
||
retval = allocate_value (subobj_type);
|
||
contents = value_contents_raw (retval);
|
||
memcpy (contents, ctx.data + subobj_byte_offset, n);
|
||
}
|
||
break;
|
||
|
||
case DWARF_VALUE_OPTIMIZED_OUT:
|
||
free_values.free_to_mark ();
|
||
retval = allocate_optimized_out_value (subobj_type);
|
||
break;
|
||
|
||
/* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
|
||
operation by execute_stack_op. */
|
||
case DWARF_VALUE_IMPLICIT_POINTER:
|
||
/* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
|
||
it can only be encountered when making a piece. */
|
||
default:
|
||
internal_error (__FILE__, __LINE__, _("invalid location type"));
|
||
}
|
||
}
|
||
|
||
set_value_initialized (retval, ctx.initialized);
|
||
|
||
return retval;
|
||
}
|
||
|
||
/* The exported interface to dwarf2_evaluate_loc_desc_full; it always
|
||
passes 0 as the byte_offset. */
|
||
|
||
struct value *
|
||
dwarf2_evaluate_loc_desc (struct type *type, struct frame_info *frame,
|
||
const gdb_byte *data, size_t size,
|
||
struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
return dwarf2_evaluate_loc_desc_full (type, frame, data, size, per_cu,
|
||
NULL, 0);
|
||
}
|
||
|
||
/* Evaluates a dwarf expression and stores the result in VAL, expecting
|
||
that the dwarf expression only produces a single CORE_ADDR. FRAME is the
|
||
frame in which the expression is evaluated. ADDR is a context (location of
|
||
a variable) and might be needed to evaluate the location expression.
|
||
Returns 1 on success, 0 otherwise. */
|
||
|
||
static int
|
||
dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
|
||
struct frame_info *frame,
|
||
CORE_ADDR addr,
|
||
CORE_ADDR *valp)
|
||
{
|
||
struct objfile *objfile;
|
||
|
||
if (dlbaton == NULL || dlbaton->size == 0)
|
||
return 0;
|
||
|
||
dwarf_evaluate_loc_desc ctx;
|
||
|
||
ctx.frame = frame;
|
||
ctx.per_cu = dlbaton->per_cu;
|
||
ctx.obj_address = addr;
|
||
|
||
objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
|
||
|
||
ctx.gdbarch = get_objfile_arch (objfile);
|
||
ctx.addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
ctx.ref_addr_size = dwarf2_per_cu_ref_addr_size (dlbaton->per_cu);
|
||
ctx.offset = dwarf2_per_cu_text_offset (dlbaton->per_cu);
|
||
|
||
ctx.eval (dlbaton->data, dlbaton->size);
|
||
|
||
switch (ctx.location)
|
||
{
|
||
case DWARF_VALUE_REGISTER:
|
||
case DWARF_VALUE_MEMORY:
|
||
case DWARF_VALUE_STACK:
|
||
*valp = ctx.fetch_address (0);
|
||
if (ctx.location == DWARF_VALUE_REGISTER)
|
||
*valp = ctx.read_addr_from_reg (*valp);
|
||
return 1;
|
||
case DWARF_VALUE_LITERAL:
|
||
*valp = extract_signed_integer (ctx.data, ctx.len,
|
||
gdbarch_byte_order (ctx.gdbarch));
|
||
return 1;
|
||
/* Unsupported dwarf values. */
|
||
case DWARF_VALUE_OPTIMIZED_OUT:
|
||
case DWARF_VALUE_IMPLICIT_POINTER:
|
||
break;
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* See dwarf2loc.h. */
|
||
|
||
int
|
||
dwarf2_evaluate_property (const struct dynamic_prop *prop,
|
||
struct frame_info *frame,
|
||
struct property_addr_info *addr_stack,
|
||
CORE_ADDR *value)
|
||
{
|
||
if (prop == NULL)
|
||
return 0;
|
||
|
||
if (frame == NULL && has_stack_frames ())
|
||
frame = get_selected_frame (NULL);
|
||
|
||
switch (prop->kind)
|
||
{
|
||
case PROP_LOCEXPR:
|
||
{
|
||
const struct dwarf2_property_baton *baton
|
||
= (const struct dwarf2_property_baton *) prop->data.baton;
|
||
|
||
if (dwarf2_locexpr_baton_eval (&baton->locexpr, frame,
|
||
addr_stack ? addr_stack->addr : 0,
|
||
value))
|
||
{
|
||
if (baton->referenced_type)
|
||
{
|
||
struct value *val = value_at (baton->referenced_type, *value);
|
||
|
||
*value = value_as_address (val);
|
||
}
|
||
return 1;
|
||
}
|
||
}
|
||
break;
|
||
|
||
case PROP_LOCLIST:
|
||
{
|
||
struct dwarf2_property_baton *baton
|
||
= (struct dwarf2_property_baton *) prop->data.baton;
|
||
CORE_ADDR pc = get_frame_address_in_block (frame);
|
||
const gdb_byte *data;
|
||
struct value *val;
|
||
size_t size;
|
||
|
||
data = dwarf2_find_location_expression (&baton->loclist, &size, pc);
|
||
if (data != NULL)
|
||
{
|
||
val = dwarf2_evaluate_loc_desc (baton->referenced_type, frame, data,
|
||
size, baton->loclist.per_cu);
|
||
if (!value_optimized_out (val))
|
||
{
|
||
*value = value_as_address (val);
|
||
return 1;
|
||
}
|
||
}
|
||
}
|
||
break;
|
||
|
||
case PROP_CONST:
|
||
*value = prop->data.const_val;
|
||
return 1;
|
||
|
||
case PROP_ADDR_OFFSET:
|
||
{
|
||
struct dwarf2_property_baton *baton
|
||
= (struct dwarf2_property_baton *) prop->data.baton;
|
||
struct property_addr_info *pinfo;
|
||
struct value *val;
|
||
|
||
for (pinfo = addr_stack; pinfo != NULL; pinfo = pinfo->next)
|
||
if (pinfo->type == baton->referenced_type)
|
||
break;
|
||
if (pinfo == NULL)
|
||
error (_("cannot find reference address for offset property"));
|
||
if (pinfo->valaddr != NULL)
|
||
val = value_from_contents
|
||
(baton->offset_info.type,
|
||
pinfo->valaddr + baton->offset_info.offset);
|
||
else
|
||
val = value_at (baton->offset_info.type,
|
||
pinfo->addr + baton->offset_info.offset);
|
||
*value = value_as_address (val);
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* See dwarf2loc.h. */
|
||
|
||
void
|
||
dwarf2_compile_property_to_c (string_file &stream,
|
||
const char *result_name,
|
||
struct gdbarch *gdbarch,
|
||
unsigned char *registers_used,
|
||
const struct dynamic_prop *prop,
|
||
CORE_ADDR pc,
|
||
struct symbol *sym)
|
||
{
|
||
struct dwarf2_property_baton *baton
|
||
= (struct dwarf2_property_baton *) prop->data.baton;
|
||
const gdb_byte *data;
|
||
size_t size;
|
||
struct dwarf2_per_cu_data *per_cu;
|
||
|
||
if (prop->kind == PROP_LOCEXPR)
|
||
{
|
||
data = baton->locexpr.data;
|
||
size = baton->locexpr.size;
|
||
per_cu = baton->locexpr.per_cu;
|
||
}
|
||
else
|
||
{
|
||
gdb_assert (prop->kind == PROP_LOCLIST);
|
||
|
||
data = dwarf2_find_location_expression (&baton->loclist, &size, pc);
|
||
per_cu = baton->loclist.per_cu;
|
||
}
|
||
|
||
compile_dwarf_bounds_to_c (stream, result_name, prop, sym, pc,
|
||
gdbarch, registers_used,
|
||
dwarf2_per_cu_addr_size (per_cu),
|
||
data, data + size, per_cu);
|
||
}
|
||
|
||
|
||
/* Helper functions and baton for dwarf2_loc_desc_get_symbol_read_needs. */
|
||
|
||
class symbol_needs_eval_context : public dwarf_expr_context
|
||
{
|
||
public:
|
||
|
||
enum symbol_needs_kind needs;
|
||
struct dwarf2_per_cu_data *per_cu;
|
||
|
||
/* Reads from registers do require a frame. */
|
||
CORE_ADDR read_addr_from_reg (int regnum) OVERRIDE
|
||
{
|
||
needs = SYMBOL_NEEDS_FRAME;
|
||
return 1;
|
||
}
|
||
|
||
/* "get_reg_value" callback: Reads from registers do require a
|
||
frame. */
|
||
|
||
struct value *get_reg_value (struct type *type, int regnum) OVERRIDE
|
||
{
|
||
needs = SYMBOL_NEEDS_FRAME;
|
||
return value_zero (type, not_lval);
|
||
}
|
||
|
||
/* Reads from memory do not require a frame. */
|
||
void read_mem (gdb_byte *buf, CORE_ADDR addr, size_t len) OVERRIDE
|
||
{
|
||
memset (buf, 0, len);
|
||
}
|
||
|
||
/* Frame-relative accesses do require a frame. */
|
||
void get_frame_base (const gdb_byte **start, size_t *length) OVERRIDE
|
||
{
|
||
static gdb_byte lit0 = DW_OP_lit0;
|
||
|
||
*start = &lit0;
|
||
*length = 1;
|
||
|
||
needs = SYMBOL_NEEDS_FRAME;
|
||
}
|
||
|
||
/* CFA accesses require a frame. */
|
||
CORE_ADDR get_frame_cfa () OVERRIDE
|
||
{
|
||
needs = SYMBOL_NEEDS_FRAME;
|
||
return 1;
|
||
}
|
||
|
||
CORE_ADDR get_frame_pc () OVERRIDE
|
||
{
|
||
needs = SYMBOL_NEEDS_FRAME;
|
||
return 1;
|
||
}
|
||
|
||
/* Thread-local accesses require registers, but not a frame. */
|
||
CORE_ADDR get_tls_address (CORE_ADDR offset) OVERRIDE
|
||
{
|
||
if (needs <= SYMBOL_NEEDS_REGISTERS)
|
||
needs = SYMBOL_NEEDS_REGISTERS;
|
||
return 1;
|
||
}
|
||
|
||
/* Helper interface of per_cu_dwarf_call for
|
||
dwarf2_loc_desc_get_symbol_read_needs. */
|
||
|
||
void dwarf_call (cu_offset die_offset) OVERRIDE
|
||
{
|
||
per_cu_dwarf_call (this, die_offset, per_cu);
|
||
}
|
||
|
||
/* DW_OP_entry_value accesses require a caller, therefore a
|
||
frame. */
|
||
|
||
void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind,
|
||
union call_site_parameter_u kind_u,
|
||
int deref_size) OVERRIDE
|
||
{
|
||
needs = SYMBOL_NEEDS_FRAME;
|
||
|
||
/* The expression may require some stub values on DWARF stack. */
|
||
push_address (0, 0);
|
||
}
|
||
|
||
/* DW_OP_GNU_addr_index doesn't require a frame. */
|
||
|
||
CORE_ADDR get_addr_index (unsigned int index) OVERRIDE
|
||
{
|
||
/* Nothing to do. */
|
||
return 1;
|
||
}
|
||
|
||
/* DW_OP_push_object_address has a frame already passed through. */
|
||
|
||
CORE_ADDR get_object_address () OVERRIDE
|
||
{
|
||
/* Nothing to do. */
|
||
return 1;
|
||
}
|
||
};
|
||
|
||
/* Compute the correct symbol_needs_kind value for the location
|
||
expression at DATA (length SIZE). */
|
||
|
||
static enum symbol_needs_kind
|
||
dwarf2_loc_desc_get_symbol_read_needs (const gdb_byte *data, size_t size,
|
||
struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
int in_reg;
|
||
struct objfile *objfile = dwarf2_per_cu_objfile (per_cu);
|
||
|
||
scoped_value_mark free_values;
|
||
|
||
symbol_needs_eval_context ctx;
|
||
|
||
ctx.needs = SYMBOL_NEEDS_NONE;
|
||
ctx.per_cu = per_cu;
|
||
ctx.gdbarch = get_objfile_arch (objfile);
|
||
ctx.addr_size = dwarf2_per_cu_addr_size (per_cu);
|
||
ctx.ref_addr_size = dwarf2_per_cu_ref_addr_size (per_cu);
|
||
ctx.offset = dwarf2_per_cu_text_offset (per_cu);
|
||
|
||
ctx.eval (data, size);
|
||
|
||
in_reg = ctx.location == DWARF_VALUE_REGISTER;
|
||
|
||
/* If the location has several pieces, and any of them are in
|
||
registers, then we will need a frame to fetch them from. */
|
||
for (dwarf_expr_piece &p : ctx.pieces)
|
||
if (p.location == DWARF_VALUE_REGISTER)
|
||
in_reg = 1;
|
||
|
||
if (in_reg)
|
||
ctx.needs = SYMBOL_NEEDS_FRAME;
|
||
return ctx.needs;
|
||
}
|
||
|
||
/* A helper function that throws an unimplemented error mentioning a
|
||
given DWARF operator. */
|
||
|
||
static void
|
||
unimplemented (unsigned int op)
|
||
{
|
||
const char *name = get_DW_OP_name (op);
|
||
|
||
if (name)
|
||
error (_("DWARF operator %s cannot be translated to an agent expression"),
|
||
name);
|
||
else
|
||
error (_("Unknown DWARF operator 0x%02x cannot be translated "
|
||
"to an agent expression"),
|
||
op);
|
||
}
|
||
|
||
/* See dwarf2loc.h.
|
||
|
||
This is basically a wrapper on gdbarch_dwarf2_reg_to_regnum so that we
|
||
can issue a complaint, which is better than having every target's
|
||
implementation of dwarf2_reg_to_regnum do it. */
|
||
|
||
int
|
||
dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg)
|
||
{
|
||
int reg = gdbarch_dwarf2_reg_to_regnum (arch, dwarf_reg);
|
||
|
||
if (reg == -1)
|
||
{
|
||
complaint (&symfile_complaints,
|
||
_("bad DWARF register number %d"), dwarf_reg);
|
||
}
|
||
return reg;
|
||
}
|
||
|
||
/* Subroutine of dwarf_reg_to_regnum_or_error to simplify it.
|
||
Throw an error because DWARF_REG is bad. */
|
||
|
||
static void
|
||
throw_bad_regnum_error (ULONGEST dwarf_reg)
|
||
{
|
||
/* Still want to print -1 as "-1".
|
||
We *could* have int and ULONGEST versions of dwarf2_reg_to_regnum_or_error
|
||
but that's overkill for now. */
|
||
if ((int) dwarf_reg == dwarf_reg)
|
||
error (_("Unable to access DWARF register number %d"), (int) dwarf_reg);
|
||
error (_("Unable to access DWARF register number %s"),
|
||
pulongest (dwarf_reg));
|
||
}
|
||
|
||
/* See dwarf2loc.h. */
|
||
|
||
int
|
||
dwarf_reg_to_regnum_or_error (struct gdbarch *arch, ULONGEST dwarf_reg)
|
||
{
|
||
int reg;
|
||
|
||
if (dwarf_reg > INT_MAX)
|
||
throw_bad_regnum_error (dwarf_reg);
|
||
/* Yes, we will end up issuing a complaint and an error if DWARF_REG is
|
||
bad, but that's ok. */
|
||
reg = dwarf_reg_to_regnum (arch, (int) dwarf_reg);
|
||
if (reg == -1)
|
||
throw_bad_regnum_error (dwarf_reg);
|
||
return reg;
|
||
}
|
||
|
||
/* A helper function that emits an access to memory. ARCH is the
|
||
target architecture. EXPR is the expression which we are building.
|
||
NBITS is the number of bits we want to read. This emits the
|
||
opcodes needed to read the memory and then extract the desired
|
||
bits. */
|
||
|
||
static void
|
||
access_memory (struct gdbarch *arch, struct agent_expr *expr, ULONGEST nbits)
|
||
{
|
||
ULONGEST nbytes = (nbits + 7) / 8;
|
||
|
||
gdb_assert (nbytes > 0 && nbytes <= sizeof (LONGEST));
|
||
|
||
if (expr->tracing)
|
||
ax_trace_quick (expr, nbytes);
|
||
|
||
if (nbits <= 8)
|
||
ax_simple (expr, aop_ref8);
|
||
else if (nbits <= 16)
|
||
ax_simple (expr, aop_ref16);
|
||
else if (nbits <= 32)
|
||
ax_simple (expr, aop_ref32);
|
||
else
|
||
ax_simple (expr, aop_ref64);
|
||
|
||
/* If we read exactly the number of bytes we wanted, we're done. */
|
||
if (8 * nbytes == nbits)
|
||
return;
|
||
|
||
if (gdbarch_bits_big_endian (arch))
|
||
{
|
||
/* On a bits-big-endian machine, we want the high-order
|
||
NBITS. */
|
||
ax_const_l (expr, 8 * nbytes - nbits);
|
||
ax_simple (expr, aop_rsh_unsigned);
|
||
}
|
||
else
|
||
{
|
||
/* On a bits-little-endian box, we want the low-order NBITS. */
|
||
ax_zero_ext (expr, nbits);
|
||
}
|
||
}
|
||
|
||
/* A helper function to return the frame's PC. */
|
||
|
||
static CORE_ADDR
|
||
get_ax_pc (void *baton)
|
||
{
|
||
struct agent_expr *expr = (struct agent_expr *) baton;
|
||
|
||
return expr->scope;
|
||
}
|
||
|
||
/* Compile a DWARF location expression to an agent expression.
|
||
|
||
EXPR is the agent expression we are building.
|
||
LOC is the agent value we modify.
|
||
ARCH is the architecture.
|
||
ADDR_SIZE is the size of addresses, in bytes.
|
||
OP_PTR is the start of the location expression.
|
||
OP_END is one past the last byte of the location expression.
|
||
|
||
This will throw an exception for various kinds of errors -- for
|
||
example, if the expression cannot be compiled, or if the expression
|
||
is invalid. */
|
||
|
||
void
|
||
dwarf2_compile_expr_to_ax (struct agent_expr *expr, struct axs_value *loc,
|
||
unsigned int addr_size, const gdb_byte *op_ptr,
|
||
const gdb_byte *op_end,
|
||
struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
gdbarch *arch = expr->gdbarch;
|
||
int i;
|
||
std::vector<int> dw_labels, patches;
|
||
const gdb_byte * const base = op_ptr;
|
||
const gdb_byte *previous_piece = op_ptr;
|
||
enum bfd_endian byte_order = gdbarch_byte_order (arch);
|
||
ULONGEST bits_collected = 0;
|
||
unsigned int addr_size_bits = 8 * addr_size;
|
||
int bits_big_endian = gdbarch_bits_big_endian (arch);
|
||
|
||
std::vector<int> offsets (op_end - op_ptr, -1);
|
||
|
||
/* By default we are making an address. */
|
||
loc->kind = axs_lvalue_memory;
|
||
|
||
while (op_ptr < op_end)
|
||
{
|
||
enum dwarf_location_atom op = (enum dwarf_location_atom) *op_ptr;
|
||
uint64_t uoffset, reg;
|
||
int64_t offset;
|
||
int i;
|
||
|
||
offsets[op_ptr - base] = expr->len;
|
||
++op_ptr;
|
||
|
||
/* Our basic approach to code generation is to map DWARF
|
||
operations directly to AX operations. However, there are
|
||
some differences.
|
||
|
||
First, DWARF works on address-sized units, but AX always uses
|
||
LONGEST. For most operations we simply ignore this
|
||
difference; instead we generate sign extensions as needed
|
||
before division and comparison operations. It would be nice
|
||
to omit the sign extensions, but there is no way to determine
|
||
the size of the target's LONGEST. (This code uses the size
|
||
of the host LONGEST in some cases -- that is a bug but it is
|
||
difficult to fix.)
|
||
|
||
Second, some DWARF operations cannot be translated to AX.
|
||
For these we simply fail. See
|
||
http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
|
||
switch (op)
|
||
{
|
||
case DW_OP_lit0:
|
||
case DW_OP_lit1:
|
||
case DW_OP_lit2:
|
||
case DW_OP_lit3:
|
||
case DW_OP_lit4:
|
||
case DW_OP_lit5:
|
||
case DW_OP_lit6:
|
||
case DW_OP_lit7:
|
||
case DW_OP_lit8:
|
||
case DW_OP_lit9:
|
||
case DW_OP_lit10:
|
||
case DW_OP_lit11:
|
||
case DW_OP_lit12:
|
||
case DW_OP_lit13:
|
||
case DW_OP_lit14:
|
||
case DW_OP_lit15:
|
||
case DW_OP_lit16:
|
||
case DW_OP_lit17:
|
||
case DW_OP_lit18:
|
||
case DW_OP_lit19:
|
||
case DW_OP_lit20:
|
||
case DW_OP_lit21:
|
||
case DW_OP_lit22:
|
||
case DW_OP_lit23:
|
||
case DW_OP_lit24:
|
||
case DW_OP_lit25:
|
||
case DW_OP_lit26:
|
||
case DW_OP_lit27:
|
||
case DW_OP_lit28:
|
||
case DW_OP_lit29:
|
||
case DW_OP_lit30:
|
||
case DW_OP_lit31:
|
||
ax_const_l (expr, op - DW_OP_lit0);
|
||
break;
|
||
|
||
case DW_OP_addr:
|
||
uoffset = extract_unsigned_integer (op_ptr, addr_size, byte_order);
|
||
op_ptr += addr_size;
|
||
/* Some versions of GCC emit DW_OP_addr before
|
||
DW_OP_GNU_push_tls_address. In this case the value is an
|
||
index, not an address. We don't support things like
|
||
branching between the address and the TLS op. */
|
||
if (op_ptr >= op_end || *op_ptr != DW_OP_GNU_push_tls_address)
|
||
uoffset += dwarf2_per_cu_text_offset (per_cu);
|
||
ax_const_l (expr, uoffset);
|
||
break;
|
||
|
||
case DW_OP_const1u:
|
||
ax_const_l (expr, extract_unsigned_integer (op_ptr, 1, byte_order));
|
||
op_ptr += 1;
|
||
break;
|
||
case DW_OP_const1s:
|
||
ax_const_l (expr, extract_signed_integer (op_ptr, 1, byte_order));
|
||
op_ptr += 1;
|
||
break;
|
||
case DW_OP_const2u:
|
||
ax_const_l (expr, extract_unsigned_integer (op_ptr, 2, byte_order));
|
||
op_ptr += 2;
|
||
break;
|
||
case DW_OP_const2s:
|
||
ax_const_l (expr, extract_signed_integer (op_ptr, 2, byte_order));
|
||
op_ptr += 2;
|
||
break;
|
||
case DW_OP_const4u:
|
||
ax_const_l (expr, extract_unsigned_integer (op_ptr, 4, byte_order));
|
||
op_ptr += 4;
|
||
break;
|
||
case DW_OP_const4s:
|
||
ax_const_l (expr, extract_signed_integer (op_ptr, 4, byte_order));
|
||
op_ptr += 4;
|
||
break;
|
||
case DW_OP_const8u:
|
||
ax_const_l (expr, extract_unsigned_integer (op_ptr, 8, byte_order));
|
||
op_ptr += 8;
|
||
break;
|
||
case DW_OP_const8s:
|
||
ax_const_l (expr, extract_signed_integer (op_ptr, 8, byte_order));
|
||
op_ptr += 8;
|
||
break;
|
||
case DW_OP_constu:
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, &uoffset);
|
||
ax_const_l (expr, uoffset);
|
||
break;
|
||
case DW_OP_consts:
|
||
op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
|
||
ax_const_l (expr, offset);
|
||
break;
|
||
|
||
case DW_OP_reg0:
|
||
case DW_OP_reg1:
|
||
case DW_OP_reg2:
|
||
case DW_OP_reg3:
|
||
case DW_OP_reg4:
|
||
case DW_OP_reg5:
|
||
case DW_OP_reg6:
|
||
case DW_OP_reg7:
|
||
case DW_OP_reg8:
|
||
case DW_OP_reg9:
|
||
case DW_OP_reg10:
|
||
case DW_OP_reg11:
|
||
case DW_OP_reg12:
|
||
case DW_OP_reg13:
|
||
case DW_OP_reg14:
|
||
case DW_OP_reg15:
|
||
case DW_OP_reg16:
|
||
case DW_OP_reg17:
|
||
case DW_OP_reg18:
|
||
case DW_OP_reg19:
|
||
case DW_OP_reg20:
|
||
case DW_OP_reg21:
|
||
case DW_OP_reg22:
|
||
case DW_OP_reg23:
|
||
case DW_OP_reg24:
|
||
case DW_OP_reg25:
|
||
case DW_OP_reg26:
|
||
case DW_OP_reg27:
|
||
case DW_OP_reg28:
|
||
case DW_OP_reg29:
|
||
case DW_OP_reg30:
|
||
case DW_OP_reg31:
|
||
dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
|
||
loc->u.reg = dwarf_reg_to_regnum_or_error (arch, op - DW_OP_reg0);
|
||
loc->kind = axs_lvalue_register;
|
||
break;
|
||
|
||
case DW_OP_regx:
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, ®);
|
||
dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_regx");
|
||
loc->u.reg = dwarf_reg_to_regnum_or_error (arch, reg);
|
||
loc->kind = axs_lvalue_register;
|
||
break;
|
||
|
||
case DW_OP_implicit_value:
|
||
{
|
||
uint64_t len;
|
||
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, &len);
|
||
if (op_ptr + len > op_end)
|
||
error (_("DW_OP_implicit_value: too few bytes available."));
|
||
if (len > sizeof (ULONGEST))
|
||
error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
|
||
(int) len);
|
||
|
||
ax_const_l (expr, extract_unsigned_integer (op_ptr, len,
|
||
byte_order));
|
||
op_ptr += len;
|
||
dwarf_expr_require_composition (op_ptr, op_end,
|
||
"DW_OP_implicit_value");
|
||
|
||
loc->kind = axs_rvalue;
|
||
}
|
||
break;
|
||
|
||
case DW_OP_stack_value:
|
||
dwarf_expr_require_composition (op_ptr, op_end, "DW_OP_stack_value");
|
||
loc->kind = axs_rvalue;
|
||
break;
|
||
|
||
case DW_OP_breg0:
|
||
case DW_OP_breg1:
|
||
case DW_OP_breg2:
|
||
case DW_OP_breg3:
|
||
case DW_OP_breg4:
|
||
case DW_OP_breg5:
|
||
case DW_OP_breg6:
|
||
case DW_OP_breg7:
|
||
case DW_OP_breg8:
|
||
case DW_OP_breg9:
|
||
case DW_OP_breg10:
|
||
case DW_OP_breg11:
|
||
case DW_OP_breg12:
|
||
case DW_OP_breg13:
|
||
case DW_OP_breg14:
|
||
case DW_OP_breg15:
|
||
case DW_OP_breg16:
|
||
case DW_OP_breg17:
|
||
case DW_OP_breg18:
|
||
case DW_OP_breg19:
|
||
case DW_OP_breg20:
|
||
case DW_OP_breg21:
|
||
case DW_OP_breg22:
|
||
case DW_OP_breg23:
|
||
case DW_OP_breg24:
|
||
case DW_OP_breg25:
|
||
case DW_OP_breg26:
|
||
case DW_OP_breg27:
|
||
case DW_OP_breg28:
|
||
case DW_OP_breg29:
|
||
case DW_OP_breg30:
|
||
case DW_OP_breg31:
|
||
op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
|
||
i = dwarf_reg_to_regnum_or_error (arch, op - DW_OP_breg0);
|
||
ax_reg (expr, i);
|
||
if (offset != 0)
|
||
{
|
||
ax_const_l (expr, offset);
|
||
ax_simple (expr, aop_add);
|
||
}
|
||
break;
|
||
case DW_OP_bregx:
|
||
{
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, ®);
|
||
op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
|
||
i = dwarf_reg_to_regnum_or_error (arch, reg);
|
||
ax_reg (expr, i);
|
||
if (offset != 0)
|
||
{
|
||
ax_const_l (expr, offset);
|
||
ax_simple (expr, aop_add);
|
||
}
|
||
}
|
||
break;
|
||
case DW_OP_fbreg:
|
||
{
|
||
const gdb_byte *datastart;
|
||
size_t datalen;
|
||
const struct block *b;
|
||
struct symbol *framefunc;
|
||
|
||
b = block_for_pc (expr->scope);
|
||
|
||
if (!b)
|
||
error (_("No block found for address"));
|
||
|
||
framefunc = block_linkage_function (b);
|
||
|
||
if (!framefunc)
|
||
error (_("No function found for block"));
|
||
|
||
func_get_frame_base_dwarf_block (framefunc, expr->scope,
|
||
&datastart, &datalen);
|
||
|
||
op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
|
||
dwarf2_compile_expr_to_ax (expr, loc, addr_size, datastart,
|
||
datastart + datalen, per_cu);
|
||
if (loc->kind == axs_lvalue_register)
|
||
require_rvalue (expr, loc);
|
||
|
||
if (offset != 0)
|
||
{
|
||
ax_const_l (expr, offset);
|
||
ax_simple (expr, aop_add);
|
||
}
|
||
|
||
loc->kind = axs_lvalue_memory;
|
||
}
|
||
break;
|
||
|
||
case DW_OP_dup:
|
||
ax_simple (expr, aop_dup);
|
||
break;
|
||
|
||
case DW_OP_drop:
|
||
ax_simple (expr, aop_pop);
|
||
break;
|
||
|
||
case DW_OP_pick:
|
||
offset = *op_ptr++;
|
||
ax_pick (expr, offset);
|
||
break;
|
||
|
||
case DW_OP_swap:
|
||
ax_simple (expr, aop_swap);
|
||
break;
|
||
|
||
case DW_OP_over:
|
||
ax_pick (expr, 1);
|
||
break;
|
||
|
||
case DW_OP_rot:
|
||
ax_simple (expr, aop_rot);
|
||
break;
|
||
|
||
case DW_OP_deref:
|
||
case DW_OP_deref_size:
|
||
{
|
||
int size;
|
||
|
||
if (op == DW_OP_deref_size)
|
||
size = *op_ptr++;
|
||
else
|
||
size = addr_size;
|
||
|
||
if (size != 1 && size != 2 && size != 4 && size != 8)
|
||
error (_("Unsupported size %d in %s"),
|
||
size, get_DW_OP_name (op));
|
||
access_memory (arch, expr, size * TARGET_CHAR_BIT);
|
||
}
|
||
break;
|
||
|
||
case DW_OP_abs:
|
||
/* Sign extend the operand. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_dup);
|
||
ax_const_l (expr, 0);
|
||
ax_simple (expr, aop_less_signed);
|
||
ax_simple (expr, aop_log_not);
|
||
i = ax_goto (expr, aop_if_goto);
|
||
/* We have to emit 0 - X. */
|
||
ax_const_l (expr, 0);
|
||
ax_simple (expr, aop_swap);
|
||
ax_simple (expr, aop_sub);
|
||
ax_label (expr, i, expr->len);
|
||
break;
|
||
|
||
case DW_OP_neg:
|
||
/* No need to sign extend here. */
|
||
ax_const_l (expr, 0);
|
||
ax_simple (expr, aop_swap);
|
||
ax_simple (expr, aop_sub);
|
||
break;
|
||
|
||
case DW_OP_not:
|
||
/* Sign extend the operand. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_bit_not);
|
||
break;
|
||
|
||
case DW_OP_plus_uconst:
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, ®);
|
||
/* It would be really weird to emit `DW_OP_plus_uconst 0',
|
||
but we micro-optimize anyhow. */
|
||
if (reg != 0)
|
||
{
|
||
ax_const_l (expr, reg);
|
||
ax_simple (expr, aop_add);
|
||
}
|
||
break;
|
||
|
||
case DW_OP_and:
|
||
ax_simple (expr, aop_bit_and);
|
||
break;
|
||
|
||
case DW_OP_div:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_simple (expr, aop_div_signed);
|
||
break;
|
||
|
||
case DW_OP_minus:
|
||
ax_simple (expr, aop_sub);
|
||
break;
|
||
|
||
case DW_OP_mod:
|
||
ax_simple (expr, aop_rem_unsigned);
|
||
break;
|
||
|
||
case DW_OP_mul:
|
||
ax_simple (expr, aop_mul);
|
||
break;
|
||
|
||
case DW_OP_or:
|
||
ax_simple (expr, aop_bit_or);
|
||
break;
|
||
|
||
case DW_OP_plus:
|
||
ax_simple (expr, aop_add);
|
||
break;
|
||
|
||
case DW_OP_shl:
|
||
ax_simple (expr, aop_lsh);
|
||
break;
|
||
|
||
case DW_OP_shr:
|
||
ax_simple (expr, aop_rsh_unsigned);
|
||
break;
|
||
|
||
case DW_OP_shra:
|
||
ax_simple (expr, aop_rsh_signed);
|
||
break;
|
||
|
||
case DW_OP_xor:
|
||
ax_simple (expr, aop_bit_xor);
|
||
break;
|
||
|
||
case DW_OP_le:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
/* Note no swap here: A <= B is !(B < A). */
|
||
ax_simple (expr, aop_less_signed);
|
||
ax_simple (expr, aop_log_not);
|
||
break;
|
||
|
||
case DW_OP_ge:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
/* A >= B is !(A < B). */
|
||
ax_simple (expr, aop_less_signed);
|
||
ax_simple (expr, aop_log_not);
|
||
break;
|
||
|
||
case DW_OP_eq:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
/* No need for a second swap here. */
|
||
ax_simple (expr, aop_equal);
|
||
break;
|
||
|
||
case DW_OP_lt:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_simple (expr, aop_less_signed);
|
||
break;
|
||
|
||
case DW_OP_gt:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
/* Note no swap here: A > B is B < A. */
|
||
ax_simple (expr, aop_less_signed);
|
||
break;
|
||
|
||
case DW_OP_ne:
|
||
/* Sign extend the operands. */
|
||
ax_ext (expr, addr_size_bits);
|
||
ax_simple (expr, aop_swap);
|
||
ax_ext (expr, addr_size_bits);
|
||
/* No need for a swap here. */
|
||
ax_simple (expr, aop_equal);
|
||
ax_simple (expr, aop_log_not);
|
||
break;
|
||
|
||
case DW_OP_call_frame_cfa:
|
||
{
|
||
int regnum;
|
||
CORE_ADDR text_offset;
|
||
LONGEST off;
|
||
const gdb_byte *cfa_start, *cfa_end;
|
||
|
||
if (dwarf2_fetch_cfa_info (arch, expr->scope, per_cu,
|
||
®num, &off,
|
||
&text_offset, &cfa_start, &cfa_end))
|
||
{
|
||
/* Register. */
|
||
ax_reg (expr, regnum);
|
||
if (off != 0)
|
||
{
|
||
ax_const_l (expr, off);
|
||
ax_simple (expr, aop_add);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Another expression. */
|
||
ax_const_l (expr, text_offset);
|
||
dwarf2_compile_expr_to_ax (expr, loc, addr_size, cfa_start,
|
||
cfa_end, per_cu);
|
||
}
|
||
|
||
loc->kind = axs_lvalue_memory;
|
||
}
|
||
break;
|
||
|
||
case DW_OP_GNU_push_tls_address:
|
||
case DW_OP_form_tls_address:
|
||
unimplemented (op);
|
||
break;
|
||
|
||
case DW_OP_push_object_address:
|
||
unimplemented (op);
|
||
break;
|
||
|
||
case DW_OP_skip:
|
||
offset = extract_signed_integer (op_ptr, 2, byte_order);
|
||
op_ptr += 2;
|
||
i = ax_goto (expr, aop_goto);
|
||
dw_labels.push_back (op_ptr + offset - base);
|
||
patches.push_back (i);
|
||
break;
|
||
|
||
case DW_OP_bra:
|
||
offset = extract_signed_integer (op_ptr, 2, byte_order);
|
||
op_ptr += 2;
|
||
/* Zero extend the operand. */
|
||
ax_zero_ext (expr, addr_size_bits);
|
||
i = ax_goto (expr, aop_if_goto);
|
||
dw_labels.push_back (op_ptr + offset - base);
|
||
patches.push_back (i);
|
||
break;
|
||
|
||
case DW_OP_nop:
|
||
break;
|
||
|
||
case DW_OP_piece:
|
||
case DW_OP_bit_piece:
|
||
{
|
||
uint64_t size, offset;
|
||
|
||
if (op_ptr - 1 == previous_piece)
|
||
error (_("Cannot translate empty pieces to agent expressions"));
|
||
previous_piece = op_ptr - 1;
|
||
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, &size);
|
||
if (op == DW_OP_piece)
|
||
{
|
||
size *= 8;
|
||
offset = 0;
|
||
}
|
||
else
|
||
op_ptr = safe_read_uleb128 (op_ptr, op_end, &offset);
|
||
|
||
if (bits_collected + size > 8 * sizeof (LONGEST))
|
||
error (_("Expression pieces exceed word size"));
|
||
|
||
/* Access the bits. */
|
||
switch (loc->kind)
|
||
{
|
||
case axs_lvalue_register:
|
||
ax_reg (expr, loc->u.reg);
|
||
break;
|
||
|
||
case axs_lvalue_memory:
|
||
/* Offset the pointer, if needed. */
|
||
if (offset > 8)
|
||
{
|
||
ax_const_l (expr, offset / 8);
|
||
ax_simple (expr, aop_add);
|
||
offset %= 8;
|
||
}
|
||
access_memory (arch, expr, size);
|
||
break;
|
||
}
|
||
|
||
/* For a bits-big-endian target, shift up what we already
|
||
have. For a bits-little-endian target, shift up the
|
||
new data. Note that there is a potential bug here if
|
||
the DWARF expression leaves multiple values on the
|
||
stack. */
|
||
if (bits_collected > 0)
|
||
{
|
||
if (bits_big_endian)
|
||
{
|
||
ax_simple (expr, aop_swap);
|
||
ax_const_l (expr, size);
|
||
ax_simple (expr, aop_lsh);
|
||
/* We don't need a second swap here, because
|
||
aop_bit_or is symmetric. */
|
||
}
|
||
else
|
||
{
|
||
ax_const_l (expr, size);
|
||
ax_simple (expr, aop_lsh);
|
||
}
|
||
ax_simple (expr, aop_bit_or);
|
||
}
|
||
|
||
bits_collected += size;
|
||
loc->kind = axs_rvalue;
|
||
}
|
||
break;
|
||
|
||
case DW_OP_GNU_uninit:
|
||
unimplemented (op);
|
||
|
||
case DW_OP_call2:
|
||
case DW_OP_call4:
|
||
{
|
||
struct dwarf2_locexpr_baton block;
|
||
int size = (op == DW_OP_call2 ? 2 : 4);
|
||
|
||
uoffset = extract_unsigned_integer (op_ptr, size, byte_order);
|
||
op_ptr += size;
|
||
|
||
cu_offset offset = (cu_offset) uoffset;
|
||
block = dwarf2_fetch_die_loc_cu_off (offset, per_cu,
|
||
get_ax_pc, expr);
|
||
|
||
/* DW_OP_call_ref is currently not supported. */
|
||
gdb_assert (block.per_cu == per_cu);
|
||
|
||
dwarf2_compile_expr_to_ax (expr, loc, addr_size, block.data,
|
||
block.data + block.size, per_cu);
|
||
}
|
||
break;
|
||
|
||
case DW_OP_call_ref:
|
||
unimplemented (op);
|
||
|
||
default:
|
||
unimplemented (op);
|
||
}
|
||
}
|
||
|
||
/* Patch all the branches we emitted. */
|
||
for (i = 0; i < patches.size (); ++i)
|
||
{
|
||
int targ = offsets[dw_labels[i]];
|
||
if (targ == -1)
|
||
internal_error (__FILE__, __LINE__, _("invalid label"));
|
||
ax_label (expr, patches[i], targ);
|
||
}
|
||
}
|
||
|
||
|
||
/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
|
||
evaluator to calculate the location. */
|
||
static struct value *
|
||
locexpr_read_variable (struct symbol *symbol, struct frame_info *frame)
|
||
{
|
||
struct dwarf2_locexpr_baton *dlbaton
|
||
= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
struct value *val;
|
||
|
||
val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, dlbaton->data,
|
||
dlbaton->size, dlbaton->per_cu);
|
||
|
||
return val;
|
||
}
|
||
|
||
/* Return the value of SYMBOL in FRAME at (callee) FRAME's function
|
||
entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
|
||
will be thrown. */
|
||
|
||
static struct value *
|
||
locexpr_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame)
|
||
{
|
||
struct dwarf2_locexpr_baton *dlbaton
|
||
= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
|
||
return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, dlbaton->data,
|
||
dlbaton->size);
|
||
}
|
||
|
||
/* Implementation of get_symbol_read_needs from
|
||
symbol_computed_ops. */
|
||
|
||
static enum symbol_needs_kind
|
||
locexpr_get_symbol_read_needs (struct symbol *symbol)
|
||
{
|
||
struct dwarf2_locexpr_baton *dlbaton
|
||
= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
|
||
return dwarf2_loc_desc_get_symbol_read_needs (dlbaton->data, dlbaton->size,
|
||
dlbaton->per_cu);
|
||
}
|
||
|
||
/* Return true if DATA points to the end of a piece. END is one past
|
||
the last byte in the expression. */
|
||
|
||
static int
|
||
piece_end_p (const gdb_byte *data, const gdb_byte *end)
|
||
{
|
||
return data == end || data[0] == DW_OP_piece || data[0] == DW_OP_bit_piece;
|
||
}
|
||
|
||
/* Helper for locexpr_describe_location_piece that finds the name of a
|
||
DWARF register. */
|
||
|
||
static const char *
|
||
locexpr_regname (struct gdbarch *gdbarch, int dwarf_regnum)
|
||
{
|
||
int regnum;
|
||
|
||
/* This doesn't use dwarf_reg_to_regnum_or_error on purpose.
|
||
We'd rather print *something* here than throw an error. */
|
||
regnum = dwarf_reg_to_regnum (gdbarch, dwarf_regnum);
|
||
/* gdbarch_register_name may just return "", return something more
|
||
descriptive for bad register numbers. */
|
||
if (regnum == -1)
|
||
{
|
||
/* The text is output as "$bad_register_number".
|
||
That is why we use the underscores. */
|
||
return _("bad_register_number");
|
||
}
|
||
return gdbarch_register_name (gdbarch, regnum);
|
||
}
|
||
|
||
/* Nicely describe a single piece of a location, returning an updated
|
||
position in the bytecode sequence. This function cannot recognize
|
||
all locations; if a location is not recognized, it simply returns
|
||
DATA. If there is an error during reading, e.g. we run off the end
|
||
of the buffer, an error is thrown. */
|
||
|
||
static const gdb_byte *
|
||
locexpr_describe_location_piece (struct symbol *symbol, struct ui_file *stream,
|
||
CORE_ADDR addr, struct objfile *objfile,
|
||
struct dwarf2_per_cu_data *per_cu,
|
||
const gdb_byte *data, const gdb_byte *end,
|
||
unsigned int addr_size)
|
||
{
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
size_t leb128_size;
|
||
|
||
if (data[0] >= DW_OP_reg0 && data[0] <= DW_OP_reg31)
|
||
{
|
||
fprintf_filtered (stream, _("a variable in $%s"),
|
||
locexpr_regname (gdbarch, data[0] - DW_OP_reg0));
|
||
data += 1;
|
||
}
|
||
else if (data[0] == DW_OP_regx)
|
||
{
|
||
uint64_t reg;
|
||
|
||
data = safe_read_uleb128 (data + 1, end, ®);
|
||
fprintf_filtered (stream, _("a variable in $%s"),
|
||
locexpr_regname (gdbarch, reg));
|
||
}
|
||
else if (data[0] == DW_OP_fbreg)
|
||
{
|
||
const struct block *b;
|
||
struct symbol *framefunc;
|
||
int frame_reg = 0;
|
||
int64_t frame_offset;
|
||
const gdb_byte *base_data, *new_data, *save_data = data;
|
||
size_t base_size;
|
||
int64_t base_offset = 0;
|
||
|
||
new_data = safe_read_sleb128 (data + 1, end, &frame_offset);
|
||
if (!piece_end_p (new_data, end))
|
||
return data;
|
||
data = new_data;
|
||
|
||
b = block_for_pc (addr);
|
||
|
||
if (!b)
|
||
error (_("No block found for address for symbol \"%s\"."),
|
||
SYMBOL_PRINT_NAME (symbol));
|
||
|
||
framefunc = block_linkage_function (b);
|
||
|
||
if (!framefunc)
|
||
error (_("No function found for block for symbol \"%s\"."),
|
||
SYMBOL_PRINT_NAME (symbol));
|
||
|
||
func_get_frame_base_dwarf_block (framefunc, addr, &base_data, &base_size);
|
||
|
||
if (base_data[0] >= DW_OP_breg0 && base_data[0] <= DW_OP_breg31)
|
||
{
|
||
const gdb_byte *buf_end;
|
||
|
||
frame_reg = base_data[0] - DW_OP_breg0;
|
||
buf_end = safe_read_sleb128 (base_data + 1, base_data + base_size,
|
||
&base_offset);
|
||
if (buf_end != base_data + base_size)
|
||
error (_("Unexpected opcode after "
|
||
"DW_OP_breg%u for symbol \"%s\"."),
|
||
frame_reg, SYMBOL_PRINT_NAME (symbol));
|
||
}
|
||
else if (base_data[0] >= DW_OP_reg0 && base_data[0] <= DW_OP_reg31)
|
||
{
|
||
/* The frame base is just the register, with no offset. */
|
||
frame_reg = base_data[0] - DW_OP_reg0;
|
||
base_offset = 0;
|
||
}
|
||
else
|
||
{
|
||
/* We don't know what to do with the frame base expression,
|
||
so we can't trace this variable; give up. */
|
||
return save_data;
|
||
}
|
||
|
||
fprintf_filtered (stream,
|
||
_("a variable at frame base reg $%s offset %s+%s"),
|
||
locexpr_regname (gdbarch, frame_reg),
|
||
plongest (base_offset), plongest (frame_offset));
|
||
}
|
||
else if (data[0] >= DW_OP_breg0 && data[0] <= DW_OP_breg31
|
||
&& piece_end_p (data, end))
|
||
{
|
||
int64_t offset;
|
||
|
||
data = safe_read_sleb128 (data + 1, end, &offset);
|
||
|
||
fprintf_filtered (stream,
|
||
_("a variable at offset %s from base reg $%s"),
|
||
plongest (offset),
|
||
locexpr_regname (gdbarch, data[0] - DW_OP_breg0));
|
||
}
|
||
|
||
/* The location expression for a TLS variable looks like this (on a
|
||
64-bit LE machine):
|
||
|
||
DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
|
||
(DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
|
||
|
||
0x3 is the encoding for DW_OP_addr, which has an operand as long
|
||
as the size of an address on the target machine (here is 8
|
||
bytes). Note that more recent version of GCC emit DW_OP_const4u
|
||
or DW_OP_const8u, depending on address size, rather than
|
||
DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
|
||
The operand represents the offset at which the variable is within
|
||
the thread local storage. */
|
||
|
||
else if (data + 1 + addr_size < end
|
||
&& (data[0] == DW_OP_addr
|
||
|| (addr_size == 4 && data[0] == DW_OP_const4u)
|
||
|| (addr_size == 8 && data[0] == DW_OP_const8u))
|
||
&& (data[1 + addr_size] == DW_OP_GNU_push_tls_address
|
||
|| data[1 + addr_size] == DW_OP_form_tls_address)
|
||
&& piece_end_p (data + 2 + addr_size, end))
|
||
{
|
||
ULONGEST offset;
|
||
offset = extract_unsigned_integer (data + 1, addr_size,
|
||
gdbarch_byte_order (gdbarch));
|
||
|
||
fprintf_filtered (stream,
|
||
_("a thread-local variable at offset 0x%s "
|
||
"in the thread-local storage for `%s'"),
|
||
phex_nz (offset, addr_size), objfile_name (objfile));
|
||
|
||
data += 1 + addr_size + 1;
|
||
}
|
||
|
||
/* With -gsplit-dwarf a TLS variable can also look like this:
|
||
DW_AT_location : 3 byte block: fc 4 e0
|
||
(DW_OP_GNU_const_index: 4;
|
||
DW_OP_GNU_push_tls_address) */
|
||
else if (data + 3 <= end
|
||
&& data + 1 + (leb128_size = skip_leb128 (data + 1, end)) < end
|
||
&& data[0] == DW_OP_GNU_const_index
|
||
&& leb128_size > 0
|
||
&& (data[1 + leb128_size] == DW_OP_GNU_push_tls_address
|
||
|| data[1 + leb128_size] == DW_OP_form_tls_address)
|
||
&& piece_end_p (data + 2 + leb128_size, end))
|
||
{
|
||
uint64_t offset;
|
||
|
||
data = safe_read_uleb128 (data + 1, end, &offset);
|
||
offset = dwarf2_read_addr_index (per_cu, offset);
|
||
fprintf_filtered (stream,
|
||
_("a thread-local variable at offset 0x%s "
|
||
"in the thread-local storage for `%s'"),
|
||
phex_nz (offset, addr_size), objfile_name (objfile));
|
||
++data;
|
||
}
|
||
|
||
else if (data[0] >= DW_OP_lit0
|
||
&& data[0] <= DW_OP_lit31
|
||
&& data + 1 < end
|
||
&& data[1] == DW_OP_stack_value)
|
||
{
|
||
fprintf_filtered (stream, _("the constant %d"), data[0] - DW_OP_lit0);
|
||
data += 2;
|
||
}
|
||
|
||
return data;
|
||
}
|
||
|
||
/* Disassemble an expression, stopping at the end of a piece or at the
|
||
end of the expression. Returns a pointer to the next unread byte
|
||
in the input expression. If ALL is nonzero, then this function
|
||
will keep going until it reaches the end of the expression.
|
||
If there is an error during reading, e.g. we run off the end
|
||
of the buffer, an error is thrown. */
|
||
|
||
static const gdb_byte *
|
||
disassemble_dwarf_expression (struct ui_file *stream,
|
||
struct gdbarch *arch, unsigned int addr_size,
|
||
int offset_size, const gdb_byte *start,
|
||
const gdb_byte *data, const gdb_byte *end,
|
||
int indent, int all,
|
||
struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
while (data < end
|
||
&& (all
|
||
|| (data[0] != DW_OP_piece && data[0] != DW_OP_bit_piece)))
|
||
{
|
||
enum dwarf_location_atom op = (enum dwarf_location_atom) *data++;
|
||
uint64_t ul;
|
||
int64_t l;
|
||
const char *name;
|
||
|
||
name = get_DW_OP_name (op);
|
||
|
||
if (!name)
|
||
error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
|
||
op, (long) (data - 1 - start));
|
||
fprintf_filtered (stream, " %*ld: %s", indent + 4,
|
||
(long) (data - 1 - start), name);
|
||
|
||
switch (op)
|
||
{
|
||
case DW_OP_addr:
|
||
ul = extract_unsigned_integer (data, addr_size,
|
||
gdbarch_byte_order (arch));
|
||
data += addr_size;
|
||
fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size));
|
||
break;
|
||
|
||
case DW_OP_const1u:
|
||
ul = extract_unsigned_integer (data, 1, gdbarch_byte_order (arch));
|
||
data += 1;
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
case DW_OP_const1s:
|
||
l = extract_signed_integer (data, 1, gdbarch_byte_order (arch));
|
||
data += 1;
|
||
fprintf_filtered (stream, " %s", plongest (l));
|
||
break;
|
||
case DW_OP_const2u:
|
||
ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
|
||
data += 2;
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
case DW_OP_const2s:
|
||
l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
|
||
data += 2;
|
||
fprintf_filtered (stream, " %s", plongest (l));
|
||
break;
|
||
case DW_OP_const4u:
|
||
ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
|
||
data += 4;
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
case DW_OP_const4s:
|
||
l = extract_signed_integer (data, 4, gdbarch_byte_order (arch));
|
||
data += 4;
|
||
fprintf_filtered (stream, " %s", plongest (l));
|
||
break;
|
||
case DW_OP_const8u:
|
||
ul = extract_unsigned_integer (data, 8, gdbarch_byte_order (arch));
|
||
data += 8;
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
case DW_OP_const8s:
|
||
l = extract_signed_integer (data, 8, gdbarch_byte_order (arch));
|
||
data += 8;
|
||
fprintf_filtered (stream, " %s", plongest (l));
|
||
break;
|
||
case DW_OP_constu:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
case DW_OP_consts:
|
||
data = safe_read_sleb128 (data, end, &l);
|
||
fprintf_filtered (stream, " %s", plongest (l));
|
||
break;
|
||
|
||
case DW_OP_reg0:
|
||
case DW_OP_reg1:
|
||
case DW_OP_reg2:
|
||
case DW_OP_reg3:
|
||
case DW_OP_reg4:
|
||
case DW_OP_reg5:
|
||
case DW_OP_reg6:
|
||
case DW_OP_reg7:
|
||
case DW_OP_reg8:
|
||
case DW_OP_reg9:
|
||
case DW_OP_reg10:
|
||
case DW_OP_reg11:
|
||
case DW_OP_reg12:
|
||
case DW_OP_reg13:
|
||
case DW_OP_reg14:
|
||
case DW_OP_reg15:
|
||
case DW_OP_reg16:
|
||
case DW_OP_reg17:
|
||
case DW_OP_reg18:
|
||
case DW_OP_reg19:
|
||
case DW_OP_reg20:
|
||
case DW_OP_reg21:
|
||
case DW_OP_reg22:
|
||
case DW_OP_reg23:
|
||
case DW_OP_reg24:
|
||
case DW_OP_reg25:
|
||
case DW_OP_reg26:
|
||
case DW_OP_reg27:
|
||
case DW_OP_reg28:
|
||
case DW_OP_reg29:
|
||
case DW_OP_reg30:
|
||
case DW_OP_reg31:
|
||
fprintf_filtered (stream, " [$%s]",
|
||
locexpr_regname (arch, op - DW_OP_reg0));
|
||
break;
|
||
|
||
case DW_OP_regx:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
fprintf_filtered (stream, " %s [$%s]", pulongest (ul),
|
||
locexpr_regname (arch, (int) ul));
|
||
break;
|
||
|
||
case DW_OP_implicit_value:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
data += ul;
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
|
||
case DW_OP_breg0:
|
||
case DW_OP_breg1:
|
||
case DW_OP_breg2:
|
||
case DW_OP_breg3:
|
||
case DW_OP_breg4:
|
||
case DW_OP_breg5:
|
||
case DW_OP_breg6:
|
||
case DW_OP_breg7:
|
||
case DW_OP_breg8:
|
||
case DW_OP_breg9:
|
||
case DW_OP_breg10:
|
||
case DW_OP_breg11:
|
||
case DW_OP_breg12:
|
||
case DW_OP_breg13:
|
||
case DW_OP_breg14:
|
||
case DW_OP_breg15:
|
||
case DW_OP_breg16:
|
||
case DW_OP_breg17:
|
||
case DW_OP_breg18:
|
||
case DW_OP_breg19:
|
||
case DW_OP_breg20:
|
||
case DW_OP_breg21:
|
||
case DW_OP_breg22:
|
||
case DW_OP_breg23:
|
||
case DW_OP_breg24:
|
||
case DW_OP_breg25:
|
||
case DW_OP_breg26:
|
||
case DW_OP_breg27:
|
||
case DW_OP_breg28:
|
||
case DW_OP_breg29:
|
||
case DW_OP_breg30:
|
||
case DW_OP_breg31:
|
||
data = safe_read_sleb128 (data, end, &l);
|
||
fprintf_filtered (stream, " %s [$%s]", plongest (l),
|
||
locexpr_regname (arch, op - DW_OP_breg0));
|
||
break;
|
||
|
||
case DW_OP_bregx:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
data = safe_read_sleb128 (data, end, &l);
|
||
fprintf_filtered (stream, " register %s [$%s] offset %s",
|
||
pulongest (ul),
|
||
locexpr_regname (arch, (int) ul),
|
||
plongest (l));
|
||
break;
|
||
|
||
case DW_OP_fbreg:
|
||
data = safe_read_sleb128 (data, end, &l);
|
||
fprintf_filtered (stream, " %s", plongest (l));
|
||
break;
|
||
|
||
case DW_OP_xderef_size:
|
||
case DW_OP_deref_size:
|
||
case DW_OP_pick:
|
||
fprintf_filtered (stream, " %d", *data);
|
||
++data;
|
||
break;
|
||
|
||
case DW_OP_plus_uconst:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
|
||
case DW_OP_skip:
|
||
l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
|
||
data += 2;
|
||
fprintf_filtered (stream, " to %ld",
|
||
(long) (data + l - start));
|
||
break;
|
||
|
||
case DW_OP_bra:
|
||
l = extract_signed_integer (data, 2, gdbarch_byte_order (arch));
|
||
data += 2;
|
||
fprintf_filtered (stream, " %ld",
|
||
(long) (data + l - start));
|
||
break;
|
||
|
||
case DW_OP_call2:
|
||
ul = extract_unsigned_integer (data, 2, gdbarch_byte_order (arch));
|
||
data += 2;
|
||
fprintf_filtered (stream, " offset %s", phex_nz (ul, 2));
|
||
break;
|
||
|
||
case DW_OP_call4:
|
||
ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
|
||
data += 4;
|
||
fprintf_filtered (stream, " offset %s", phex_nz (ul, 4));
|
||
break;
|
||
|
||
case DW_OP_call_ref:
|
||
ul = extract_unsigned_integer (data, offset_size,
|
||
gdbarch_byte_order (arch));
|
||
data += offset_size;
|
||
fprintf_filtered (stream, " offset %s", phex_nz (ul, offset_size));
|
||
break;
|
||
|
||
case DW_OP_piece:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
fprintf_filtered (stream, " %s (bytes)", pulongest (ul));
|
||
break;
|
||
|
||
case DW_OP_bit_piece:
|
||
{
|
||
uint64_t offset;
|
||
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
data = safe_read_uleb128 (data, end, &offset);
|
||
fprintf_filtered (stream, " size %s offset %s (bits)",
|
||
pulongest (ul), pulongest (offset));
|
||
}
|
||
break;
|
||
|
||
case DW_OP_implicit_pointer:
|
||
case DW_OP_GNU_implicit_pointer:
|
||
{
|
||
ul = extract_unsigned_integer (data, offset_size,
|
||
gdbarch_byte_order (arch));
|
||
data += offset_size;
|
||
|
||
data = safe_read_sleb128 (data, end, &l);
|
||
|
||
fprintf_filtered (stream, " DIE %s offset %s",
|
||
phex_nz (ul, offset_size),
|
||
plongest (l));
|
||
}
|
||
break;
|
||
|
||
case DW_OP_deref_type:
|
||
case DW_OP_GNU_deref_type:
|
||
{
|
||
int addr_size = *data++;
|
||
struct type *type;
|
||
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
cu_offset offset = (cu_offset) ul;
|
||
type = dwarf2_get_die_type (offset, per_cu);
|
||
fprintf_filtered (stream, "<");
|
||
type_print (type, "", stream, -1);
|
||
fprintf_filtered (stream, " [0x%s]> %d",
|
||
phex_nz (to_underlying (offset), 0),
|
||
addr_size);
|
||
}
|
||
break;
|
||
|
||
case DW_OP_const_type:
|
||
case DW_OP_GNU_const_type:
|
||
{
|
||
struct type *type;
|
||
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
cu_offset type_die = (cu_offset) ul;
|
||
type = dwarf2_get_die_type (type_die, per_cu);
|
||
fprintf_filtered (stream, "<");
|
||
type_print (type, "", stream, -1);
|
||
fprintf_filtered (stream, " [0x%s]>",
|
||
phex_nz (to_underlying (type_die), 0));
|
||
}
|
||
break;
|
||
|
||
case DW_OP_regval_type:
|
||
case DW_OP_GNU_regval_type:
|
||
{
|
||
uint64_t reg;
|
||
struct type *type;
|
||
|
||
data = safe_read_uleb128 (data, end, ®);
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
cu_offset type_die = (cu_offset) ul;
|
||
|
||
type = dwarf2_get_die_type (type_die, per_cu);
|
||
fprintf_filtered (stream, "<");
|
||
type_print (type, "", stream, -1);
|
||
fprintf_filtered (stream, " [0x%s]> [$%s]",
|
||
phex_nz (to_underlying (type_die), 0),
|
||
locexpr_regname (arch, reg));
|
||
}
|
||
break;
|
||
|
||
case DW_OP_convert:
|
||
case DW_OP_GNU_convert:
|
||
case DW_OP_reinterpret:
|
||
case DW_OP_GNU_reinterpret:
|
||
{
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
cu_offset type_die = (cu_offset) ul;
|
||
|
||
if (to_underlying (type_die) == 0)
|
||
fprintf_filtered (stream, "<0>");
|
||
else
|
||
{
|
||
struct type *type;
|
||
|
||
type = dwarf2_get_die_type (type_die, per_cu);
|
||
fprintf_filtered (stream, "<");
|
||
type_print (type, "", stream, -1);
|
||
fprintf_filtered (stream, " [0x%s]>",
|
||
phex_nz (to_underlying (type_die), 0));
|
||
}
|
||
}
|
||
break;
|
||
|
||
case DW_OP_entry_value:
|
||
case DW_OP_GNU_entry_value:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
fputc_filtered ('\n', stream);
|
||
disassemble_dwarf_expression (stream, arch, addr_size, offset_size,
|
||
start, data, data + ul, indent + 2,
|
||
all, per_cu);
|
||
data += ul;
|
||
continue;
|
||
|
||
case DW_OP_GNU_parameter_ref:
|
||
ul = extract_unsigned_integer (data, 4, gdbarch_byte_order (arch));
|
||
data += 4;
|
||
fprintf_filtered (stream, " offset %s", phex_nz (ul, 4));
|
||
break;
|
||
|
||
case DW_OP_GNU_addr_index:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
ul = dwarf2_read_addr_index (per_cu, ul);
|
||
fprintf_filtered (stream, " 0x%s", phex_nz (ul, addr_size));
|
||
break;
|
||
case DW_OP_GNU_const_index:
|
||
data = safe_read_uleb128 (data, end, &ul);
|
||
ul = dwarf2_read_addr_index (per_cu, ul);
|
||
fprintf_filtered (stream, " %s", pulongest (ul));
|
||
break;
|
||
}
|
||
|
||
fprintf_filtered (stream, "\n");
|
||
}
|
||
|
||
return data;
|
||
}
|
||
|
||
/* Describe a single location, which may in turn consist of multiple
|
||
pieces. */
|
||
|
||
static void
|
||
locexpr_describe_location_1 (struct symbol *symbol, CORE_ADDR addr,
|
||
struct ui_file *stream,
|
||
const gdb_byte *data, size_t size,
|
||
struct objfile *objfile, unsigned int addr_size,
|
||
int offset_size, struct dwarf2_per_cu_data *per_cu)
|
||
{
|
||
const gdb_byte *end = data + size;
|
||
int first_piece = 1, bad = 0;
|
||
|
||
while (data < end)
|
||
{
|
||
const gdb_byte *here = data;
|
||
int disassemble = 1;
|
||
|
||
if (first_piece)
|
||
first_piece = 0;
|
||
else
|
||
fprintf_filtered (stream, _(", and "));
|
||
|
||
if (!dwarf_always_disassemble)
|
||
{
|
||
data = locexpr_describe_location_piece (symbol, stream,
|
||
addr, objfile, per_cu,
|
||
data, end, addr_size);
|
||
/* If we printed anything, or if we have an empty piece,
|
||
then don't disassemble. */
|
||
if (data != here
|
||
|| data[0] == DW_OP_piece
|
||
|| data[0] == DW_OP_bit_piece)
|
||
disassemble = 0;
|
||
}
|
||
if (disassemble)
|
||
{
|
||
fprintf_filtered (stream, _("a complex DWARF expression:\n"));
|
||
data = disassemble_dwarf_expression (stream,
|
||
get_objfile_arch (objfile),
|
||
addr_size, offset_size, data,
|
||
data, end, 0,
|
||
dwarf_always_disassemble,
|
||
per_cu);
|
||
}
|
||
|
||
if (data < end)
|
||
{
|
||
int empty = data == here;
|
||
|
||
if (disassemble)
|
||
fprintf_filtered (stream, " ");
|
||
if (data[0] == DW_OP_piece)
|
||
{
|
||
uint64_t bytes;
|
||
|
||
data = safe_read_uleb128 (data + 1, end, &bytes);
|
||
|
||
if (empty)
|
||
fprintf_filtered (stream, _("an empty %s-byte piece"),
|
||
pulongest (bytes));
|
||
else
|
||
fprintf_filtered (stream, _(" [%s-byte piece]"),
|
||
pulongest (bytes));
|
||
}
|
||
else if (data[0] == DW_OP_bit_piece)
|
||
{
|
||
uint64_t bits, offset;
|
||
|
||
data = safe_read_uleb128 (data + 1, end, &bits);
|
||
data = safe_read_uleb128 (data, end, &offset);
|
||
|
||
if (empty)
|
||
fprintf_filtered (stream,
|
||
_("an empty %s-bit piece"),
|
||
pulongest (bits));
|
||
else
|
||
fprintf_filtered (stream,
|
||
_(" [%s-bit piece, offset %s bits]"),
|
||
pulongest (bits), pulongest (offset));
|
||
}
|
||
else
|
||
{
|
||
bad = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
if (bad || data > end)
|
||
error (_("Corrupted DWARF2 expression for \"%s\"."),
|
||
SYMBOL_PRINT_NAME (symbol));
|
||
}
|
||
|
||
/* Print a natural-language description of SYMBOL to STREAM. This
|
||
version is for a symbol with a single location. */
|
||
|
||
static void
|
||
locexpr_describe_location (struct symbol *symbol, CORE_ADDR addr,
|
||
struct ui_file *stream)
|
||
{
|
||
struct dwarf2_locexpr_baton *dlbaton
|
||
= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
|
||
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
|
||
|
||
locexpr_describe_location_1 (symbol, addr, stream,
|
||
dlbaton->data, dlbaton->size,
|
||
objfile, addr_size, offset_size,
|
||
dlbaton->per_cu);
|
||
}
|
||
|
||
/* Describe the location of SYMBOL as an agent value in VALUE, generating
|
||
any necessary bytecode in AX. */
|
||
|
||
static void
|
||
locexpr_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
|
||
struct axs_value *value)
|
||
{
|
||
struct dwarf2_locexpr_baton *dlbaton
|
||
= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
|
||
if (dlbaton->size == 0)
|
||
value->optimized_out = 1;
|
||
else
|
||
dwarf2_compile_expr_to_ax (ax, value, addr_size, dlbaton->data,
|
||
dlbaton->data + dlbaton->size, dlbaton->per_cu);
|
||
}
|
||
|
||
/* symbol_computed_ops 'generate_c_location' method. */
|
||
|
||
static void
|
||
locexpr_generate_c_location (struct symbol *sym, string_file &stream,
|
||
struct gdbarch *gdbarch,
|
||
unsigned char *registers_used,
|
||
CORE_ADDR pc, const char *result_name)
|
||
{
|
||
struct dwarf2_locexpr_baton *dlbaton
|
||
= (struct dwarf2_locexpr_baton *) SYMBOL_LOCATION_BATON (sym);
|
||
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
|
||
if (dlbaton->size == 0)
|
||
error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym));
|
||
|
||
compile_dwarf_expr_to_c (stream, result_name,
|
||
sym, pc, gdbarch, registers_used, addr_size,
|
||
dlbaton->data, dlbaton->data + dlbaton->size,
|
||
dlbaton->per_cu);
|
||
}
|
||
|
||
/* The set of location functions used with the DWARF-2 expression
|
||
evaluator. */
|
||
const struct symbol_computed_ops dwarf2_locexpr_funcs = {
|
||
locexpr_read_variable,
|
||
locexpr_read_variable_at_entry,
|
||
locexpr_get_symbol_read_needs,
|
||
locexpr_describe_location,
|
||
0, /* location_has_loclist */
|
||
locexpr_tracepoint_var_ref,
|
||
locexpr_generate_c_location
|
||
};
|
||
|
||
|
||
/* Wrapper functions for location lists. These generally find
|
||
the appropriate location expression and call something above. */
|
||
|
||
/* Return the value of SYMBOL in FRAME using the DWARF-2 expression
|
||
evaluator to calculate the location. */
|
||
static struct value *
|
||
loclist_read_variable (struct symbol *symbol, struct frame_info *frame)
|
||
{
|
||
struct dwarf2_loclist_baton *dlbaton
|
||
= (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
struct value *val;
|
||
const gdb_byte *data;
|
||
size_t size;
|
||
CORE_ADDR pc = frame ? get_frame_address_in_block (frame) : 0;
|
||
|
||
data = dwarf2_find_location_expression (dlbaton, &size, pc);
|
||
val = dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol), frame, data, size,
|
||
dlbaton->per_cu);
|
||
|
||
return val;
|
||
}
|
||
|
||
/* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function
|
||
entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
|
||
will be thrown.
|
||
|
||
Function always returns non-NULL value, it may be marked optimized out if
|
||
inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR
|
||
if it cannot resolve the parameter for any reason. */
|
||
|
||
static struct value *
|
||
loclist_read_variable_at_entry (struct symbol *symbol, struct frame_info *frame)
|
||
{
|
||
struct dwarf2_loclist_baton *dlbaton
|
||
= (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
const gdb_byte *data;
|
||
size_t size;
|
||
CORE_ADDR pc;
|
||
|
||
if (frame == NULL || !get_frame_func_if_available (frame, &pc))
|
||
return allocate_optimized_out_value (SYMBOL_TYPE (symbol));
|
||
|
||
data = dwarf2_find_location_expression (dlbaton, &size, pc);
|
||
if (data == NULL)
|
||
return allocate_optimized_out_value (SYMBOL_TYPE (symbol));
|
||
|
||
return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol), frame, data, size);
|
||
}
|
||
|
||
/* Implementation of get_symbol_read_needs from
|
||
symbol_computed_ops. */
|
||
|
||
static enum symbol_needs_kind
|
||
loclist_symbol_needs (struct symbol *symbol)
|
||
{
|
||
/* If there's a location list, then assume we need to have a frame
|
||
to choose the appropriate location expression. With tracking of
|
||
global variables this is not necessarily true, but such tracking
|
||
is disabled in GCC at the moment until we figure out how to
|
||
represent it. */
|
||
|
||
return SYMBOL_NEEDS_FRAME;
|
||
}
|
||
|
||
/* Print a natural-language description of SYMBOL to STREAM. This
|
||
version applies when there is a list of different locations, each
|
||
with a specified address range. */
|
||
|
||
static void
|
||
loclist_describe_location (struct symbol *symbol, CORE_ADDR addr,
|
||
struct ui_file *stream)
|
||
{
|
||
struct dwarf2_loclist_baton *dlbaton
|
||
= (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
const gdb_byte *loc_ptr, *buf_end;
|
||
struct objfile *objfile = dwarf2_per_cu_objfile (dlbaton->per_cu);
|
||
struct gdbarch *gdbarch = get_objfile_arch (objfile);
|
||
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
|
||
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
int offset_size = dwarf2_per_cu_offset_size (dlbaton->per_cu);
|
||
int signed_addr_p = bfd_get_sign_extend_vma (objfile->obfd);
|
||
/* Adjust base_address for relocatable objects. */
|
||
CORE_ADDR base_offset = dwarf2_per_cu_text_offset (dlbaton->per_cu);
|
||
CORE_ADDR base_address = dlbaton->base_address + base_offset;
|
||
int done = 0;
|
||
|
||
loc_ptr = dlbaton->data;
|
||
buf_end = dlbaton->data + dlbaton->size;
|
||
|
||
fprintf_filtered (stream, _("multi-location:\n"));
|
||
|
||
/* Iterate through locations until we run out. */
|
||
while (!done)
|
||
{
|
||
CORE_ADDR low = 0, high = 0; /* init for gcc -Wall */
|
||
int length;
|
||
enum debug_loc_kind kind;
|
||
const gdb_byte *new_ptr = NULL; /* init for gcc -Wall */
|
||
|
||
if (dlbaton->from_dwo)
|
||
kind = decode_debug_loc_dwo_addresses (dlbaton->per_cu,
|
||
loc_ptr, buf_end, &new_ptr,
|
||
&low, &high, byte_order);
|
||
else
|
||
kind = decode_debug_loc_addresses (loc_ptr, buf_end, &new_ptr,
|
||
&low, &high,
|
||
byte_order, addr_size,
|
||
signed_addr_p);
|
||
loc_ptr = new_ptr;
|
||
switch (kind)
|
||
{
|
||
case DEBUG_LOC_END_OF_LIST:
|
||
done = 1;
|
||
continue;
|
||
case DEBUG_LOC_BASE_ADDRESS:
|
||
base_address = high + base_offset;
|
||
fprintf_filtered (stream, _(" Base address %s"),
|
||
paddress (gdbarch, base_address));
|
||
continue;
|
||
case DEBUG_LOC_START_END:
|
||
case DEBUG_LOC_START_LENGTH:
|
||
break;
|
||
case DEBUG_LOC_BUFFER_OVERFLOW:
|
||
case DEBUG_LOC_INVALID_ENTRY:
|
||
error (_("Corrupted DWARF expression for symbol \"%s\"."),
|
||
SYMBOL_PRINT_NAME (symbol));
|
||
default:
|
||
gdb_assert_not_reached ("bad debug_loc_kind");
|
||
}
|
||
|
||
/* Otherwise, a location expression entry. */
|
||
low += base_address;
|
||
high += base_address;
|
||
|
||
low = gdbarch_adjust_dwarf2_addr (gdbarch, low);
|
||
high = gdbarch_adjust_dwarf2_addr (gdbarch, high);
|
||
|
||
length = extract_unsigned_integer (loc_ptr, 2, byte_order);
|
||
loc_ptr += 2;
|
||
|
||
/* (It would improve readability to print only the minimum
|
||
necessary digits of the second number of the range.) */
|
||
fprintf_filtered (stream, _(" Range %s-%s: "),
|
||
paddress (gdbarch, low), paddress (gdbarch, high));
|
||
|
||
/* Now describe this particular location. */
|
||
locexpr_describe_location_1 (symbol, low, stream, loc_ptr, length,
|
||
objfile, addr_size, offset_size,
|
||
dlbaton->per_cu);
|
||
|
||
fprintf_filtered (stream, "\n");
|
||
|
||
loc_ptr += length;
|
||
}
|
||
}
|
||
|
||
/* Describe the location of SYMBOL as an agent value in VALUE, generating
|
||
any necessary bytecode in AX. */
|
||
static void
|
||
loclist_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
|
||
struct axs_value *value)
|
||
{
|
||
struct dwarf2_loclist_baton *dlbaton
|
||
= (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (symbol);
|
||
const gdb_byte *data;
|
||
size_t size;
|
||
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
|
||
data = dwarf2_find_location_expression (dlbaton, &size, ax->scope);
|
||
if (size == 0)
|
||
value->optimized_out = 1;
|
||
else
|
||
dwarf2_compile_expr_to_ax (ax, value, addr_size, data, data + size,
|
||
dlbaton->per_cu);
|
||
}
|
||
|
||
/* symbol_computed_ops 'generate_c_location' method. */
|
||
|
||
static void
|
||
loclist_generate_c_location (struct symbol *sym, string_file &stream,
|
||
struct gdbarch *gdbarch,
|
||
unsigned char *registers_used,
|
||
CORE_ADDR pc, const char *result_name)
|
||
{
|
||
struct dwarf2_loclist_baton *dlbaton
|
||
= (struct dwarf2_loclist_baton *) SYMBOL_LOCATION_BATON (sym);
|
||
unsigned int addr_size = dwarf2_per_cu_addr_size (dlbaton->per_cu);
|
||
const gdb_byte *data;
|
||
size_t size;
|
||
|
||
data = dwarf2_find_location_expression (dlbaton, &size, pc);
|
||
if (size == 0)
|
||
error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym));
|
||
|
||
compile_dwarf_expr_to_c (stream, result_name,
|
||
sym, pc, gdbarch, registers_used, addr_size,
|
||
data, data + size,
|
||
dlbaton->per_cu);
|
||
}
|
||
|
||
/* The set of location functions used with the DWARF-2 expression
|
||
evaluator and location lists. */
|
||
const struct symbol_computed_ops dwarf2_loclist_funcs = {
|
||
loclist_read_variable,
|
||
loclist_read_variable_at_entry,
|
||
loclist_symbol_needs,
|
||
loclist_describe_location,
|
||
1, /* location_has_loclist */
|
||
loclist_tracepoint_var_ref,
|
||
loclist_generate_c_location
|
||
};
|
||
|
||
void
|
||
_initialize_dwarf2loc (void)
|
||
{
|
||
add_setshow_zuinteger_cmd ("entry-values", class_maintenance,
|
||
&entry_values_debug,
|
||
_("Set entry values and tail call frames "
|
||
"debugging."),
|
||
_("Show entry values and tail call frames "
|
||
"debugging."),
|
||
_("When non-zero, the process of determining "
|
||
"parameter values from function entry point "
|
||
"and tail call frames will be printed."),
|
||
NULL,
|
||
show_entry_values_debug,
|
||
&setdebuglist, &showdebuglist);
|
||
|
||
#if GDB_SELF_TEST
|
||
selftests::register_test ("copy_bitwise", selftests::copy_bitwise_tests);
|
||
#endif
|
||
}
|