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2005-06-20 Geoffrey Keating <geoffk@apple.com> * libiberty.h (strverscmp): Prototype. Index: libiberty/ChangeLog 2005-06-20 Geoffrey Keating <geoffk@apple.com> * strverscmp.c: New. * Makefile.in (CFILES): Add strverscmp.c. (CONFIGURED_OFILES): Add strverscmp.o. (strverscmp.o): New rule. (stamp-functions): Add $(srcdir) to files in source directory. * configure.ac (funcs): Add strverscmp. (AC_CHECK_FUNCS): Add strverscmp. * configure: Regenerate. * functions.texi: Regenerate.gdb-csl-arm-20051020-branch
Geoffrey Keating
21 years ago
8 changed files with 320 additions and 12 deletions
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/* Compare strings while treating digits characters numerically.
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Copyright (C) 1997, 2002, 2005 Free Software Foundation, Inc. |
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This file is part of the libiberty library. |
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Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997. |
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Libiberty 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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Libiberty 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, write to the Free |
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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02111-1307 USA. */ |
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#include "libiberty.h" |
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#include "safe-ctype.h" |
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/*
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@deftypefun int strverscmp (const char *@var{s1}, const char *@var{s2}) |
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The @code{strverscmp} function compares the string @var{s1} against |
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@var{s2}, considering them as holding indices/version numbers. Return |
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value follows the same conventions as found in the @code{strverscmp} |
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function. In fact, if @var{s1} and @var{s2} contain no digits, |
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@code{strverscmp} behaves like @code{strcmp}. |
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Basically, we compare strings normally (character by character), until |
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we find a digit in each string - then we enter a special comparison |
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mode, where each sequence of digits is taken as a whole. If we reach the |
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end of these two parts without noticing a difference, we return to the |
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standard comparison mode. There are two types of numeric parts: |
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"integral" and "fractional" (those begin with a '0'). The types |
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of the numeric parts affect the way we sort them: |
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@itemize @bullet |
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@item |
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integral/integral: we compare values as you would expect. |
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@item |
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fractional/integral: the fractional part is less than the integral one. |
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Again, no surprise. |
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@item |
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fractional/fractional: the things become a bit more complex. |
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If the common prefix contains only leading zeroes, the longest part is less |
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than the other one; else the comparison behaves normally. |
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@end itemize |
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@smallexample |
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strverscmp ("no digit", "no digit") |
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@result{} 0 // @r{same behavior as strcmp.}
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strverscmp ("item#99", "item#100") |
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@result{} <0 // @r{same prefix, but 99 < 100.}
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strverscmp ("alpha1", "alpha001") |
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@result{} >0 // @r{fractional part inferior to integral one.}
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strverscmp ("part1_f012", "part1_f01") |
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@result{} >0 // @r{two fractional parts.}
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strverscmp ("foo.009", "foo.0") |
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@result{} <0 // @r{idem, but with leading zeroes only.}
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@end smallexample |
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This function is especially useful when dealing with filename sorting, |
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because filenames frequently hold indices/version numbers. |
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@end deftypefun |
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*/ |
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/* states: S_N: normal, S_I: comparing integral part, S_F: comparing
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fractional parts, S_Z: idem but with leading Zeroes only */ |
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#define S_N 0x0 |
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#define S_I 0x4 |
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#define S_F 0x8 |
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#define S_Z 0xC |
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/* result_type: CMP: return diff; LEN: compare using len_diff/diff */ |
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#define CMP 2 |
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#define LEN 3 |
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/* Compare S1 and S2 as strings holding indices/version numbers,
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returning less than, equal to or greater than zero if S1 is less than, |
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equal to or greater than S2 (for more info, see the Glibc texinfo doc). */ |
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int |
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strverscmp (const char *s1, const char *s2) |
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{ |
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const unsigned char *p1 = (const unsigned char *) s1; |
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const unsigned char *p2 = (const unsigned char *) s2; |
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unsigned char c1, c2; |
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int state; |
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int diff; |
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/* Symbol(s) 0 [1-9] others (padding)
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Transition (10) 0 (01) d (00) x (11) - */ |
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static const unsigned int next_state[] = |
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{ |
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/* state x d 0 - */ |
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/* S_N */ S_N, S_I, S_Z, S_N, |
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/* S_I */ S_N, S_I, S_I, S_I, |
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/* S_F */ S_N, S_F, S_F, S_F, |
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/* S_Z */ S_N, S_F, S_Z, S_Z |
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}; |
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static const int result_type[] = |
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{ |
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/* state x/x x/d x/0 x/- d/x d/d d/0 d/-
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0/x 0/d 0/0 0/- -/x -/d -/0 -/- */ |
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/* S_N */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP, |
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CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, |
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/* S_I */ CMP, -1, -1, CMP, +1, LEN, LEN, CMP, |
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+1, LEN, LEN, CMP, CMP, CMP, CMP, CMP, |
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/* S_F */ CMP, CMP, CMP, CMP, CMP, LEN, CMP, CMP, |
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CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, |
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/* S_Z */ CMP, +1, +1, CMP, -1, CMP, CMP, CMP, |
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-1, CMP, CMP, CMP |
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}; |
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if (p1 == p2) |
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return 0; |
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c1 = *p1++; |
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c2 = *p2++; |
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/* Hint: '0' is a digit too. */ |
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state = S_N | ((c1 == '0') + (ISDIGIT (c1) != 0)); |
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while ((diff = c1 - c2) == 0 && c1 != '\0') |
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{ |
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state = next_state[state]; |
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c1 = *p1++; |
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c2 = *p2++; |
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state |= (c1 == '0') + (ISDIGIT (c1) != 0); |
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} |
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state = result_type[state << 2 | (((c2 == '0') + (ISDIGIT (c2) != 0)))]; |
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switch (state) |
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{ |
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case CMP: |
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return diff; |
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case LEN: |
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while (ISDIGIT (*p1++)) |
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if (!ISDIGIT (*p2++)) |
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return 1; |
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return ISDIGIT (*p2) ? -1 : diff; |
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default: |
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return state; |
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} |
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} |
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