The preferred implementation uses __auto_type, a GCC extension also now supported by Clang. Unfortunately OpenBSD ships with GCC 4.2.1 (from 2007!) which predates this extension by quite a few years, so we have to be able to fall back to a plain macro. --- configure.ac | 20 ++++++++++- common/include/minmax.h | 63 +++++++++++++++++++++++++++++++++++ filters/blocksize/blocksize.c | 3 +- filters/cache/lru.c | 3 +- filters/nozero/nozero.c | 3 +- plugins/pattern/pattern.c | 3 +- common/include/Makefile.am | 1 + filters/blocksize/Makefile.am | 3 +- filters/nozero/Makefile.am | 3 +- 9 files changed, 93 insertions(+), 9 deletions(-) diff --git a/configure.ac b/configure.ac index 606e632..ee1ff0d 100644 --- a/configure.ac +++ b/configure.ac @@ -156,9 +156,27 @@ you may be using a C compiler which does not support this attribute, or the configure test may be wrong. This code requires the attribute to work for proper locking between threads.])]) -dnl restore CFLAGS CFLAGS="${acx_nbdkit_save_CFLAGS}" +dnl Check for __auto_type (GCC extension). +AC_MSG_CHECKING([if __auto_type is available in this compiler]) +AC_COMPILE_IFELSE([ +AC_LANG_SOURCE([[ +static int +test (int a) +{ + __auto_type at = a; + return at; +} +]]) + ],[ + AC_MSG_RESULT([yes]) + AC_DEFINE([HAVE_AUTO_TYPE],[1],[__auto_type is available]) + ],[ + AC_MSG_RESULT([no]) + ] +) + dnl Check for other headers, all optional. AC_CHECK_HEADERS([\ alloca.h \ diff --git a/common/include/minmax.h b/common/include/minmax.h new file mode 100644 index 0000000..dc01679 --- /dev/null +++ b/common/include/minmax.h @@ -0,0 +1,63 @@ +/* nbdkit + * Copyright (C) 2019 Red Hat Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * * Neither the name of Red Hat nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef NBDKIT_MINMAX_H +#define NBDKIT_MINMAX_H + +#include <config.h> + +#ifdef HAVE_AUTO_TYPE + +/* __auto_type is a GCC extension, added in GCC 4.9 in 2014, and to + * Clang in 2015. + */ + +#define MIN(x, y) ({ \ + __auto_type _x = (x); \ + __auto_type _y = (y); \ + _x < _y ? _x : _y; \ + }) +#define MAX(x, y) ({ \ + __auto_type _x = (x); \ + __auto_type _y = (y); \ + _x > _y ? _x : _y; \ + }) + +#else + +#define MIN(x, y) ((x) < (y) ? (x) : (y)) +#define MAX(x, y) ((x) > (y) ? (x) : (y)) + +#endif + +#endif /* NBDKIT_MINMAX_H */ diff --git a/filters/blocksize/blocksize.c b/filters/blocksize/blocksize.c index 6acd9b6..34f58c9 100644 --- a/filters/blocksize/blocksize.c +++ b/filters/blocksize/blocksize.c @@ -44,11 +44,12 @@ #include <nbdkit-filter.h> +#include "minmax.h" + /* XXX See design comment in filters/cow/cow.c. */ #define THREAD_MODEL NBDKIT_THREAD_MODEL_SERIALIZE_ALL_REQUESTS #define BLOCKSIZE_MIN_LIMIT (64U * 1024) -#define MIN(a, b) ((a) < (b) ? (a) : (b)) /* As long as we don't have parallel requests, we can reuse a common * buffer for alignment purposes; size it to the maximum we allow for diff --git a/filters/cache/lru.c b/filters/cache/lru.c index c828968..9e20408 100644 --- a/filters/cache/lru.c +++ b/filters/cache/lru.c @@ -46,13 +46,12 @@ #include <nbdkit-filter.h> #include "bitmap.h" +#include "minmax.h" #include "cache.h" #include "blk.h" #include "lru.h" -#define MAX(a, b) ((a) > (b) ? (a) : (b)) - /* LRU bitmaps. These bitmaps implement a simple, fast LRU structure. * * bm[0] bm[1] blocks not in either bitmap diff --git a/filters/nozero/nozero.c b/filters/nozero/nozero.c index dac47ad..6a22f9b 100644 --- a/filters/nozero/nozero.c +++ b/filters/nozero/nozero.c @@ -42,9 +42,10 @@ #include <nbdkit-filter.h> +#include "minmax.h" + #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL -#define MIN(a, b) ((a) < (b) ? (a) : (b)) #define MAX_WRITE (64 * 1024 * 1024) static char buffer[MAX_WRITE]; diff --git a/plugins/pattern/pattern.c b/plugins/pattern/pattern.c index 1d1b234..32db381 100644 --- a/plugins/pattern/pattern.c +++ b/plugins/pattern/pattern.c @@ -45,6 +45,7 @@ #include <nbdkit-plugin.h> #include "byte-swapping.h" +#include "minmax.h" /* The size of disk in bytes (initialized by size=<SIZE> parameter). */ static int64_t size = 0; @@ -87,8 +88,6 @@ pattern_get_size (void *handle) return size; } -#define MIN(a, b) ((a) < (b) ? (a) : (b)) - /* Read data. */ static int pattern_pread (void *handle, void *buf, uint32_t count, uint64_t offset, diff --git a/common/include/Makefile.am b/common/include/Makefile.am index 3e7f056..7df4855 100644 --- a/common/include/Makefile.am +++ b/common/include/Makefile.am @@ -41,6 +41,7 @@ EXTRA_DIST = \ isaligned.h \ ispowerof2.h \ iszero.h \ + minmax.h \ nextnonzero.h \ random.h \ rounding.h diff --git a/filters/blocksize/Makefile.am b/filters/blocksize/Makefile.am index b49fc3f..231c9b5 100644 --- a/filters/blocksize/Makefile.am +++ b/filters/blocksize/Makefile.am @@ -41,7 +41,8 @@ nbdkit_blocksize_filter_la_SOURCES = \ $(top_srcdir)/include/nbdkit-filter.h nbdkit_blocksize_filter_la_CPPFLAGS = \ - -I$(top_srcdir)/include + -I$(top_srcdir)/include \ + -I$(top_srcdir)/common/include nbdkit_blocksize_filter_la_CFLAGS = \ $(WARNINGS_CFLAGS) nbdkit_blocksize_filter_la_LDFLAGS = \ diff --git a/filters/nozero/Makefile.am b/filters/nozero/Makefile.am index b1fd4a8..fe88233 100644 --- a/filters/nozero/Makefile.am +++ b/filters/nozero/Makefile.am @@ -41,7 +41,8 @@ nbdkit_nozero_filter_la_SOURCES = \ $(top_srcdir)/include/nbdkit-filter.h nbdkit_nozero_filter_la_CPPFLAGS = \ - -I$(top_srcdir)/include + -I$(top_srcdir)/include \ + -I$(top_srcdir)/common/include nbdkit_nozero_filter_la_CFLAGS = \ $(WARNINGS_CFLAGS) nbdkit_nozero_filter_la_LDFLAGS = \ -- 2.19.2