mirror of
https://github.com/openharmony/third_party_elfutils.git
synced 2026-07-19 19:43:34 -04:00
Josh Stone
c0d2a0b3a3
Quite a few DW_FORMs have a fixed length for their data, and we can easily represent these in a small lookup table. The rest of the forms are left in the old function to compute as needed. Combined with inlining, this takes care of many forms with fewer branches and without any call. (It's conceivable that a smart compiler could make a similar lookup transformation from the large switch itself, but GCC doesn't.) Signed-off-by: Josh Stone <jistone@redhat.com>
116 lines
2.9 KiB
C
116 lines
2.9 KiB
C
/* Helper functions for form handling.
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Copyright (C) 2003-2009 Red Hat, Inc.
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This file is part of elfutils.
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Written by Ulrich Drepper <drepper@redhat.com>, 2003.
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This file is free software; you can redistribute it and/or modify
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it under the terms of either
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* the GNU Lesser General Public License as published by the Free
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Software Foundation; either version 3 of the License, or (at
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your option) any later version
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or
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* the GNU General Public License as published by the Free
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Software Foundation; either version 2 of the License, or (at
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your option) any later version
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or both in parallel, as here.
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elfutils is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received copies of the GNU General Public License and
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the GNU Lesser General Public License along with this program. If
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not, see <http://www.gnu.org/licenses/>. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <dwarf.h>
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#include <string.h>
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#include "libdwP.h"
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size_t
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internal_function
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__libdw_form_val_compute_len (Dwarf *dbg, struct Dwarf_CU *cu,
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unsigned int form, const unsigned char *valp)
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{
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const unsigned char *saved;
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Dwarf_Word u128;
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size_t result;
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/* NB: This doesn't cover constant form lengths, which are
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already handled by the inlined __libdw_form_val_len. */
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switch (form)
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{
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case DW_FORM_addr:
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result = cu->address_size;
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break;
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case DW_FORM_ref_addr:
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result = cu->version == 2 ? cu->address_size : cu->offset_size;
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break;
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case DW_FORM_strp:
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case DW_FORM_sec_offset:
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case DW_FORM_GNU_ref_alt:
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case DW_FORM_GNU_strp_alt:
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result = cu->offset_size;
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break;
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case DW_FORM_block1:
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result = *valp + 1;
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break;
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case DW_FORM_block2:
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result = read_2ubyte_unaligned (dbg, valp) + 2;
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break;
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case DW_FORM_block4:
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result = read_4ubyte_unaligned (dbg, valp) + 4;
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break;
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case DW_FORM_block:
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case DW_FORM_exprloc:
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saved = valp;
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get_uleb128 (u128, valp);
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result = u128 + (valp - saved);
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break;
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case DW_FORM_string:
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result = strlen ((char *) valp) + 1;
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break;
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case DW_FORM_sdata:
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case DW_FORM_udata:
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case DW_FORM_ref_udata:
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saved = valp;
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get_uleb128 (u128, valp);
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result = valp - saved;
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break;
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case DW_FORM_indirect:
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saved = valp;
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get_uleb128 (u128, valp);
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// XXX Is this really correct?
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result = __libdw_form_val_len (dbg, cu, u128, valp);
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if (result != (size_t) -1)
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result += valp - saved;
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break;
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default:
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__libdw_seterrno (DWARF_E_INVALID_DWARF);
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result = (size_t) -1l;
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break;
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}
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return result;
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}
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