d2b02eaf59
That's not valid in C99, at least, if the value is negative or if the shift count is the number of bits in the value - 1, and we might get compile-time or run-time complaints about that. Also, make bit masks unsigned; to quote a run-time error reported in https://www.wireshark.org/lists/wireshark-dev/201504/msg00084.html "left shift of 1 by 31 places cannot be represented in type 'int'", so use type "unsigned int" instead, by shifting 1U rather than 1 left. Change-Id: I62220808058cb93f83329c1916b888a2067d524c Reviewed-on: https://code.wireshark.org/review/8254 Reviewed-by: Guy Harris <guy@alum.mit.edu>
81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/*
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* sign_ext.h
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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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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*
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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, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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#ifndef __WSUTIL_SIGN_EXT_H__
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#define __WSUTIL_SIGN_EXT_H__
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#include <glib.h>
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/* sign extension routines */
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static inline guint32
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ws_sign_ext32(guint32 val, int no_of_bits)
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{
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g_assert (no_of_bits >= 0 && no_of_bits <= 32);
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if (no_of_bits == 0)
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return val;
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/*
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* Don't shift signed values left; that's not valid in C99, at
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* least, if the value is negative or if the shift count is
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* the number of bits in the value - 1, and we might get
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* compile-time or run-time complaints about that.
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*/
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if (val & (1U << (no_of_bits-1)))
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val |= (0xFFFFFFFFU << no_of_bits);
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return val;
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}
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static inline guint64
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ws_sign_ext64(guint64 val, int no_of_bits)
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{
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g_assert (no_of_bits >= 0 && no_of_bits <= 64);
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if (no_of_bits == 0)
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return val;
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/*
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* Don't shift signed values left; that's not valid in C99, at
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* least, if the value is negative or if the shift count is
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* the number of bits in the value - 1, and we might get
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* compile-time or run-time complaints about that.
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*/
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if (val & (G_GUINT64_CONSTANT(1) << (no_of_bits-1)))
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val |= (G_GUINT64_CONSTANT(0xFFFFFFFFFFFFFFFF) << no_of_bits);
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return val;
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}
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/*
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static inline guint64
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ws_sign_ext64(guint64 val, int no_of_bits)
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{
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gint64 sval = (val << (64 - no_of_bits));
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return (guint64) (sval >> (64 - no_of_bits));
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}
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*/
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#endif /* __WSUTIL_SIGN_EXT_H__ */
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