Markus F.X.J. Oberhumer
143 lines
7.4 KiB
C++
143 lines
7.4 KiB
C++
/* ctsw.h -- call-/swaptrick filter
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This file is part of the UPX executable compressor.
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Copyright (C) 1996-2025 Markus Franz Xaver Johannes Oberhumer
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Copyright (C) 1996-2025 Laszlo Molnar
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All Rights Reserved.
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UPX and the UCL library are free software; you can redistribute them
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and/or modify them under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of
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the License, or (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; see the file COPYING.
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If not, write to the Free Software Foundation, Inc.,
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59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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Markus F.X.J. Oberhumer Laszlo Molnar
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<markus@oberhumer.com> <ezerotven+github@gmail.com>
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*/
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/*************************************************************************
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// 16-bit call-/swaptrick ("naive")
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**************************************************************************/
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#define CTSW16(f, cond1, cond2, addvalue, get, set) \
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byte *b = f->buf; \
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byte *b_end = b + f->buf_len - 3; \
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do { \
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if (cond1) { \
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b += 1; \
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unsigned a = (unsigned) (b - f->buf); \
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f->lastcall = a; \
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set(b, get(b) + (addvalue)); \
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f->calls++; \
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b += 2 - 1; \
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} else if (cond2) { \
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b += 1; \
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unsigned a = (unsigned) (b - f->buf); \
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f->lastcall = a; \
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set(b, get(b)); \
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f->calls++; \
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b += 2 - 1; \
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} \
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} while (++b < b_end); \
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if (f->lastcall) \
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f->lastcall += 2; \
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return 0;
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// filter
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static int f_ctsw16_e8_e9(Filter *f) {
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CTSW16(f, (*b == 0xe8), (*b == 0xe9), a + f->addvalue, get_le16, set_be16)
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}
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static int f_ctsw16_e9_e8(Filter *f) {
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CTSW16(f, (*b == 0xe9), (*b == 0xe8), a + f->addvalue, get_le16, set_be16)
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}
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// unfilter
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static int u_ctsw16_e8_e9(Filter *f) {
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CTSW16(f, (*b == 0xe8), (*b == 0xe9), 0 - a - f->addvalue, get_be16, set_le16)
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}
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static int u_ctsw16_e9_e8(Filter *f) {
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CTSW16(f, (*b == 0xe9), (*b == 0xe8), 0 - a - f->addvalue, get_be16, set_le16)
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}
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// scan
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static int s_ctsw16_e8_e9(Filter *f) {
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CTSW16(f, (*b == 0xe8), (*b == 0xe9), a + f->addvalue, get_le16, set_dummy)
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}
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static int s_ctsw16_e9_e8(Filter *f) {
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CTSW16(f, (*b == 0xe9), (*b == 0xe8), a + f->addvalue, get_le16, set_dummy)
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}
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#undef CTSW16
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/*************************************************************************
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// 32-bit call-/swaptrick ("naive")
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**************************************************************************/
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#define CTSW32(f, cond1, cond2, addvalue, get, set) \
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byte *b = f->buf; \
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byte *b_end = b + f->buf_len - 5; \
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do { \
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if (cond1) { \
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b += 1; \
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unsigned a = (unsigned) (b - f->buf); \
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f->lastcall = a; \
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set(b, get(b) + (addvalue)); \
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f->calls++; \
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b += 4 - 1; \
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} else if (cond2) { \
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b += 1; \
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unsigned a = (unsigned) (b - f->buf); \
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f->lastcall = a; \
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set(b, get(b)); \
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f->calls++; \
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b += 4 - 1; \
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} \
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} while (++b < b_end); \
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if (f->lastcall) \
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f->lastcall += 4; \
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return 0;
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// filter
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static int f_ctsw32_e8_e9(Filter *f) {
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CTSW32(f, (*b == 0xe8), (*b == 0xe9), a + f->addvalue, get_le32, set_be32)
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}
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static int f_ctsw32_e9_e8(Filter *f) {
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CTSW32(f, (*b == 0xe9), (*b == 0xe8), a + f->addvalue, get_le32, set_be32)
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}
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// unfilter
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static int u_ctsw32_e8_e9(Filter *f) {
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CTSW32(f, (*b == 0xe8), (*b == 0xe9), 0 - a - f->addvalue, get_be32, set_le32)
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}
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static int u_ctsw32_e9_e8(Filter *f) {
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CTSW32(f, (*b == 0xe9), (*b == 0xe8), 0 - a - f->addvalue, get_be32, set_le32)
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}
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// scan
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static int s_ctsw32_e8_e9(Filter *f) {
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CTSW32(f, (*b == 0xe8), (*b == 0xe9), a + f->addvalue, get_le32, set_dummy)
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}
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static int s_ctsw32_e9_e8(Filter *f) {
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CTSW32(f, (*b == 0xe9), (*b == 0xe8), a + f->addvalue, get_le32, set_dummy)
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}
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#undef CTSW32
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/* vim:set ts=4 sw=4 et: */
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