From 017b0b20b432df707718a19443d9435870f0b3c7 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Tue, 14 Sep 2010 13:43:07 -0600 Subject: [PATCH] memchr: detect glibc Alpha bug Avoids http://sourceware.org/bugzilla/show_bug.cgi?id=12019. * m4/memchr.m4 (gl_FUNC_MEMCHR): Detect glibc 2.11.2 failure on Alpha. * doc/posix-functions/memchr.texi (memchr): Tweak wording. * tests/test-memchr.c (main): Enhance test. Reported by Nelson H. F. Beebe. Signed-off-by: Eric Blake --- ChangeLog | 10 ++++++++++ doc/posix-functions/memchr.texi | 2 +- m4/memchr.m4 | 4 +++- tests/test-memchr.c | 18 +++++++++++++++--- 4 files changed, 29 insertions(+), 5 deletions(-) diff --git a/ChangeLog b/ChangeLog index a9cb9769d6..f4bdc7f935 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,13 @@ +2010-09-14 Eric Blake + + memchr: detect glibc Alpha bug + Avoids http://sourceware.org/bugzilla/show_bug.cgi?id=12019. + * m4/memchr.m4 (gl_FUNC_MEMCHR): Detect glibc 2.11.2 failure on + Alpha. + * doc/posix-functions/memchr.texi (memchr): Tweak wording. + * tests/test-memchr.c (main): Enhance test. + Reported by Nelson H. F. Beebe. + 2010-09-13 Paul Eggert fts, getcwd, glob: audit for dirfd returning -1 diff --git a/doc/posix-functions/memchr.texi b/doc/posix-functions/memchr.texi index 69b693a75a..3c9cfcb9d2 100644 --- a/doc/posix-functions/memchr.texi +++ b/doc/posix-functions/memchr.texi @@ -13,7 +13,7 @@ This function is missing on some older platforms. @item This function dereferences too much memory on some platforms: -glibc 2.10 on x86_64, IA-64, Alpha. +glibc 2.10 on x86_64, IA-64; glibc 2.11 on Alpha. @end itemize Portability problems not fixed by Gnulib: diff --git a/m4/memchr.m4 b/m4/memchr.m4 index ab773b8129..b05a79a026 100644 --- a/m4/memchr.m4 +++ b/m4/memchr.m4 @@ -1,4 +1,4 @@ -# memchr.m4 serial 8 +# memchr.m4 serial 9 dnl Copyright (C) 2002-2004, 2009-2010 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -62,6 +62,8 @@ AC_DEFUN_ONCE([gl_FUNC_MEMCHR], strcpy (fence - 9, "12345678"); if (memchr (fence - 9, 0, 79) != fence - 1) return 2; + if (memchr (fence - 1, 0, 3) != fence - 1) + return 3; } return 0; ]])], [gl_cv_func_memchr_works=yes], [gl_cv_func_memchr_works=no], diff --git a/tests/test-memchr.c b/tests/test-memchr.c index a801614079..e7b9780d96 100644 --- a/tests/test-memchr.c +++ b/tests/test-memchr.c @@ -87,25 +87,37 @@ main (void) /* Check that memchr() does not read past the first occurrence of the byte being searched. See the Austin Group's clarification - . */ + . + Test both '\0' and something else, since some implementations + special-case searching for NUL. + */ { char *page_boundary = (char *) zerosize_ptr (); + /* Too small, and we miss cache line boundary tests; too large, + and the test takes cubically longer to complete. */ + int limit = 257; if (page_boundary != NULL) { - for (n = 1; n <= 500; n++) + for (n = 1; n <= limit; n++) { char *mem = page_boundary - n; memset (mem, 'X', n); ASSERT (MEMCHR (mem, 'U', n) == NULL); + ASSERT (MEMCHR (mem, 0, n) == NULL); { size_t i; + size_t k; for (i = 0; i < n; i++) { mem[i] = 'U'; - ASSERT (MEMCHR (mem, 'U', 4000) == mem + i); + for (k = i + 1; k < n + limit; k++) + ASSERT (MEMCHR (mem, 'U', k) == mem + i); + mem[i] = 0; + for (k = i + 1; k < n + limit; k++) + ASSERT (MEMCHR (mem, 0, k) == mem + i); mem[i] = 'X'; } } -- 2.30.2