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ce99922090
The findidx functions used in implementing strcoll / wcscoll already use DIAG_IGNORE_Os_NEEDS_COMMENT for spurious -Wmaybe-uninitialized warnings that appear with -Os. In building with GCC 7 for x86_64 with -Os, I find there are additional such warnings, for the same structure elements, which are spurious for the same reasons given in the existing comments (and this was also reported for MIPS with GCC 5 in bug 21313). This patch adds corresponding uses of DIAG_* in the places that get the additional warnings. Tested for x86_64 with -Os that this eliminates those warnings and so allows the build to progress further. [BZ #21313] * locale/weight.h (findidx): Disable -Wmaybe-uninitialized for -Os in another place. * locale/weightwc.h (findidx): Likewise.
136 lines
3.8 KiB
C
136 lines
3.8 KiB
C
/* Copyright (C) 1996-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Written by Ulrich Drepper, <drepper@cygnus.com>.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifndef _WEIGHTWC_H_
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#define _WEIGHTWC_H_ 1
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#include <libc-diag.h>
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/* Find index of weight. */
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static inline int32_t __attribute__ ((always_inline))
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findidx (const int32_t *table,
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const int32_t *indirect,
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const wint_t *extra,
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const wint_t **cpp, size_t len)
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{
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wint_t ch = *(*cpp)++;
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int32_t i = __collidx_table_lookup ((const char *) table, ch);
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if (i >= 0)
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/* This is an index into the weight table. Cool. */
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return i;
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/* Oh well, more than one sequence starting with this byte.
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Search for the correct one. */
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const int32_t *cp = (const int32_t *) &extra[-i];
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--len;
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while (1)
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{
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size_t nhere;
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const int32_t *usrc = (const int32_t *) *cpp;
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/* The first thing is the index. */
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i = *cp++;
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/* Next is the length of the byte sequence. These are always
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short byte sequences so there is no reason to call any
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function (even if they are inlined). */
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nhere = *cp++;
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if (i >= 0)
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{
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/* It is a single character. If it matches we found our
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index. Note that at the end of each list there is an
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entry of length zero which represents the single byte
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sequence. The first (and here only) byte was tested
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already. */
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size_t cnt;
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/* With GCC 5.3 when compiling with -Os the compiler warns
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that seq2.back_us, which becomes usrc, might be used
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uninitialized. This can't be true because we pass a length
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of -1 for len at the same time which means that this loop
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never executes. */
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DIAG_PUSH_NEEDS_COMMENT;
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DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
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for (cnt = 0; cnt < nhere && cnt < len; ++cnt)
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if (cp[cnt] != usrc[cnt])
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break;
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DIAG_POP_NEEDS_COMMENT;
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if (cnt == nhere)
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{
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/* Found it. */
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*cpp += nhere;
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return i;
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}
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/* Up to the next entry. */
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cp += nhere;
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}
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else
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{
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/* This is a range of characters. First decide whether the
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current byte sequence lies in the range. */
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size_t cnt;
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size_t offset;
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/* With GCC 7 when compiling with -Os the compiler warns
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that seq1.back_us and seq2.back_us, which become usrc,
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might be used uninitialized. This is impossible for the
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same reason as described above. */
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DIAG_PUSH_NEEDS_COMMENT;
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DIAG_IGNORE_Os_NEEDS_COMMENT (7, "-Wmaybe-uninitialized");
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for (cnt = 0; cnt < nhere - 1 && cnt < len; ++cnt)
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if (cp[cnt] != usrc[cnt])
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break;
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DIAG_POP_NEEDS_COMMENT;
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if (cnt < nhere - 1)
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{
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cp += 2 * nhere;
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continue;
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}
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if (cp[nhere - 1] > usrc[nhere -1])
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{
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cp += 2 * nhere;
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continue;
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}
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if (cp[2 * nhere - 1] < usrc[nhere -1])
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{
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cp += 2 * nhere;
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continue;
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}
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/* This range matches the next characters. Now find
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the offset in the indirect table. */
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offset = usrc[nhere - 1] - cp[nhere - 1];
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*cpp += nhere;
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return indirect[-i + offset];
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}
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}
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/* NOTREACHED */
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return 0x43219876;
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}
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#endif /* weightwc.h */
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