From: Andre Noll <maan@systemlinux.org>
Date: Mon, 1 Dec 2008 15:51:37 +0000 (+0100)
Subject: Replace MAX, MIN, ABS macros by type-checking variants.
X-Git-Tag: v0.3.4~91^2
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=3062b9da4f71ea236f46efda9a51add1b15cda1a

Replace MAX, MIN, ABS macros by type-checking variants.

Taken from the Linux kernel. These macros also evaluate each parameter
only once. Fix up all resulting gcc warnings.
---

diff --git a/aft.c b/aft.c
index 5cca5b8d..d5a35556 100644
--- a/aft.c
+++ b/aft.c
@@ -1260,8 +1260,8 @@ static int prepare_ls_row(struct osl_row *row, void *ls_opts)
 	GET_NUM_DIGITS(d->afsi.num_played, &num_digits);
 	w->num_played_width = PARA_MAX(w->num_played_width, num_digits);
 	/* get the number of chars to print this amount of time */
-	tmp = get_duration_width(d->afhi.seconds_total);
-	w->duration_width = PARA_MAX(w->duration_width, tmp);
+	num_digits = get_duration_width(d->afhi.seconds_total);
+	w->duration_width = PARA_MAX(w->duration_width, num_digits);
 	GET_NUM_DIGITS(d->afsi.amp, &num_digits);
 	w->amp_width = PARA_MAX(w->amp_width, num_digits);
 	if (options->flags & LS_FLAG_ADMISSIBLE_ONLY) {
diff --git a/attribute.c b/attribute.c
index 24a3826d..655c2866 100644
--- a/attribute.c
+++ b/attribute.c
@@ -343,7 +343,7 @@ static void com_addatt_callback(int fd, const struct osl_object *query)
 		aed.name = p;
 		aed.bitnum = bitnum;
 		afs_event(ATTRIBUTE_ADD, &pb, &aed);
-		greatest_att_bitnum = PARA_MAX(greatest_att_bitnum, bitnum);
+		greatest_att_bitnum = PARA_MAX(greatest_att_bitnum, (int)bitnum);
 	}
 out:
 	if (ret < 0 && ret2 >= 0)
diff --git a/audiod.c b/audiod.c
index 33eac4b9..b9bd852a 100644
--- a/audiod.c
+++ b/audiod.c
@@ -603,7 +603,7 @@ static int init_writers(void)
 	struct audio_format_info *a;
 
 	init_supported_writers();
-	nw = PARA_MAX(1, conf.writer_given);
+	nw = PARA_MAX(1U, conf.writer_given);
 	PARA_INFO_LOG("maximal number of writers: %d\n", nw);
 	FOR_EACH_AUDIO_FORMAT(i) {
 		a = &afi[i];
@@ -720,7 +720,7 @@ static int init_filters(void)
 	int i, ret, nf;
 
 	filter_init(filters);
-	nf = PARA_MAX(1,  conf.filter_given);
+	nf = PARA_MAX(1U, conf.filter_given);
 	PARA_INFO_LOG("maximal number of filters: %d\n", nf);
 	FOR_EACH_AUDIO_FORMAT(i) {
 		afi[i].filter_conf = para_malloc(nf * sizeof(void *));
diff --git a/compress_filter.c b/compress_filter.c
index 6034ce79..bf129b4a 100644
--- a/compress_filter.c
+++ b/compress_filter.c
@@ -34,7 +34,7 @@ struct private_compress_data {
 	/** Number of samples already seen. */
 	unsigned num_samples;
 	/** Absolute value of the maximal sample in the current block. */
-	unsigned peak;
+	int peak;
 };
 
 static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
@@ -71,7 +71,7 @@ static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
 				pcd->current_gain++;
 		} else
 			pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
-				1 << pcd->conf->inertia_arg);
+				1U << pcd->conf->inertia_arg);
 		pcd->peak = 0;
 	}
 	fn->loaded += length;
diff --git a/mp3dec_filter.c b/mp3dec_filter.c
index 50e530e1..5e5df865 100644
--- a/mp3dec_filter.c
+++ b/mp3dec_filter.c
@@ -35,7 +35,7 @@ static ssize_t mp3dec(char *inbuffer, size_t len, struct filter_node *fn)
 {
 	int i, ret;
 	struct private_mp3dec_data *pmd = fn->private_data;
-	size_t copy = PARA_MIN(len, 4096);
+	size_t copy = PARA_MIN(len, (size_t)4096);
 
 	if (fn->loaded > fn->bufsize * 4 / 5)
 		return 0;
diff --git a/ogg_afh.c b/ogg_afh.c
index 11f7f5ad..b6132edf 100644
--- a/ogg_afh.c
+++ b/ogg_afh.c
@@ -34,8 +34,15 @@ struct ogg_datasource {
 static size_t cb_read(void *buf, size_t size, size_t nmemb, void *datasource)
 {
 	struct ogg_datasource *ods = datasource;
-	size_t copy = PARA_MIN(ods->numbytes - ods->fpos, size * nmemb),
-		ret = copy / size;
+	size_t copy, ret;
+
+	if (!size)
+		return 0;
+
+	assert(ods->numbytes >= ods->fpos);
+	ret = ods->numbytes - ods->fpos;
+	copy = PARA_MIN(ret, size * nmemb);
+	ret = copy / size;
 	if (!ret)
 		return 0;
 	memcpy(buf, ods->map + ods->fpos, copy);
@@ -115,7 +122,7 @@ static int ogg_compute_header_len(char *map, size_t numbytes,
 		struct afh_info *afhi)
 {
 	int ret;
-	size_t len = PARA_MIN(numbytes, CHUNK_SIZE);
+	size_t len = PARA_MIN(numbytes, (size_t)CHUNK_SIZE);
 	int serial;
 	char *buf;
 
diff --git a/para.h b/para.h
index a39ed97d..3f2da13a 100644
--- a/para.h
+++ b/para.h
@@ -30,12 +30,24 @@
 /** used in various contexts */
 #define MAXLINE 255
 
-/** compute the minimum of \a a and \a b */
-#define PARA_MIN(a,b) ((a) < (b) ? (a) : (b))
-/** compute the maximum of \a a and \a b */
-#define PARA_MAX(a,b) ((a) > (b) ? (a) : (b))
-/** compute the absolute value of \a a */
-#define PARA_ABS(a) ((a) > 0 ? (a) : -(a))
+/** Compute the minimum of \a x and \a y. */
+#define PARA_MIN(x, y) ({ \
+	typeof(x) _min1 = (x); \
+	typeof(y) _min2 = (y); \
+	(void) (&_min1 == &_min2); \
+	_min1 < _min2 ? _min1 : _min2; })
+
+/** Compute the maximum of \a x and \a y. */
+#define PARA_MAX(x, y) ({ \
+	typeof(x) _max1 = (x); \
+	typeof(y) _max2 = (y); \
+	(void) (&_max1 == &_max2); \
+	_max1 < _max2 ? _max1 : _max2; })
+
+/** Compute the absolute value of \a x. */
+#define PARA_ABS(x) ({ \
+	typeof(x) _x = (x); \
+	_x > 0? _x : -_x; })
 
 /** debug loglevel, gets really noisy */
 #define DEBUG 1
diff --git a/write.h b/write.h
index 02471f32..9723977a 100644
--- a/write.h
+++ b/write.h
@@ -95,7 +95,7 @@ struct writer_node_group {
 	/** Array of pointers to the corresponding writer nodes. */
 	struct writer_node *writer_nodes;
 	/** The maximum of the chunk_bytes values of the writer nodes in this group. */
-	size_t max_chunk_bytes;
+	int max_chunk_bytes;
 	/** Non-zero if an error or end of file was encountered by the feeding task. */
 	int *input_error;
 	/** Current output buffer. */