use gcc const and pure function attributes wherever applicable

git-svn-id: file:///home/lennart/svn/public/pulseaudio/branches/lennart@1835 fefdeb5f-60dc-0310-8127-8f9354f1896f

6 files changed, 44 insertions, 26 deletions

diff --git a/src/pulse/cdecl.h b/src/pulse/cdecl.h
index 922ad276..e1f23d25 100644
--- a/src/pulse/cdecl.h
+++ b/src/pulse/cdecl.h
@@ -41,4 +41,22 @@
 
 #endif
 
+#ifndef PA_GCC_PURE
+#ifdef __GNUCC__
+#define PA_GCC_PURE __attribute__ ((pure))
+#else
+/** This function's return value depends only the arguments list and global state **/
+#define PA_GCC_PURE
+#endif
+#endif
+
+#ifndef PA_GCC_CONST
+#ifdef __GNUCC__
+#define PA_GCC_CONST __attribute__ ((pure))
+#else
+/** This function's return value depends only the arguments list (stricter version of PA_GCC_CONST) **/
+#define PA_GCC_CONST
+#endif
+#endif
+
 #endif
diff --git a/src/pulse/channelmap.h b/src/pulse/channelmap.h
index bb8ce952..a05e1911 100644
--- a/src/pulse/channelmap.h
+++ b/src/pulse/channelmap.h
@@ -172,7 +172,7 @@ pa_channel_map* pa_channel_map_init_stereo(pa_channel_map *m);
 pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsigned channels, pa_channel_map_def_t def);
 
 /** Return a text label for the specified channel position */
-const char* pa_channel_position_to_string(pa_channel_position_t pos);
+const char* pa_channel_position_to_string(pa_channel_position_t pos) PA_GCC_PURE;
 
 /** Return a human readable text label for the specified channel position. \since 0.9.7 */
 const char* pa_channel_position_to_pretty_string(pa_channel_position_t pos);
@@ -187,10 +187,10 @@ char* pa_channel_map_snprint(char *s, size_t l, const pa_channel_map *map);
 pa_channel_map *pa_channel_map_parse(pa_channel_map *map, const char *s);
 
 /** Compare two channel maps. Return 1 if both match. */
-int pa_channel_map_equal(const pa_channel_map *a, const pa_channel_map *b);
+int pa_channel_map_equal(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE;
 
 /** Return non-zero of the specified channel map is considered valid */
-int pa_channel_map_valid(const pa_channel_map *map);
+int pa_channel_map_valid(const pa_channel_map *map) PA_GCC_PURE;
 
 PA_C_DECL_END
 
diff --git a/src/pulse/sample.h b/src/pulse/sample.h
index 683167cc..b307621e 100644
--- a/src/pulse/sample.h
+++ b/src/pulse/sample.h
@@ -155,31 +155,31 @@ typedef struct pa_sample_spec {
 typedef uint64_t pa_usec_t;
 
 /** Return the amount of bytes playback of a second of audio with the specified sample type takes */
-size_t pa_bytes_per_second(const pa_sample_spec *spec);
+size_t pa_bytes_per_second(const pa_sample_spec *spec) PA_GCC_PURE;
 
 /** Return the size of a frame with the specific sample type */
-size_t pa_frame_size(const pa_sample_spec *spec);
+size_t pa_frame_size(const pa_sample_spec *spec) PA_GCC_PURE;
 
 /** Return the size of a sample with the specific sample type */
-size_t pa_sample_size(const pa_sample_spec *spec);
+size_t pa_sample_size(const pa_sample_spec *spec) PA_GCC_PURE;
 
 /** Calculate the time the specified bytes take to play with the specified sample type */
-pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec);
+pa_usec_t pa_bytes_to_usec(uint64_t length, const pa_sample_spec *spec) PA_GCC_PURE;
 
 /** Calculates the number of bytes that are required for the specified time. \since 0.9 */
-size_t pa_usec_to_bytes(pa_usec_t t, const pa_sample_spec *spec);
+size_t pa_usec_to_bytes(pa_usec_t t, const pa_sample_spec *spec) PA_GCC_PURE;
 
 /** Return non-zero when the sample type specification is valid */
-int pa_sample_spec_valid(const pa_sample_spec *spec);
+int pa_sample_spec_valid(const pa_sample_spec *spec) PA_GCC_PURE;
 
 /** Return non-zero when the two sample type specifications match */
-int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b);
+int pa_sample_spec_equal(const pa_sample_spec*a, const pa_sample_spec*b) PA_GCC_PURE;
 
 /** Return a descriptive string for the specified sample format. \since 0.8 */
-const char *pa_sample_format_to_string(pa_sample_format_t f);
+const char *pa_sample_format_to_string(pa_sample_format_t f) PA_GCC_PURE;
 
 /** Parse a sample format text. Inverse of pa_sample_format_to_string() */
-pa_sample_format_t pa_parse_sample_format(const char *format);
+pa_sample_format_t pa_parse_sample_format(const char *format) PA_GCC_PURE;
 
 /** Maximum required string length for pa_sample_spec_snprint() */
 #define PA_SAMPLE_SPEC_SNPRINT_MAX 32
diff --git a/src/pulse/timeval.h b/src/pulse/timeval.h
index dbf4319c..e90df9f8 100644
--- a/src/pulse/timeval.h
+++ b/src/pulse/timeval.h
@@ -44,16 +44,16 @@ struct timeval *pa_gettimeofday(struct timeval *tv);
 
 /** Calculate the difference between the two specified timeval
  * structs. */
-pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b);
+pa_usec_t pa_timeval_diff(const struct timeval *a, const struct timeval *b) PA_GCC_PURE;
 
 /** Compare the two timeval structs and return 0 when equal, negative when a < b, positive otherwse */
-int pa_timeval_cmp(const struct timeval *a, const struct timeval *b);
+int pa_timeval_cmp(const struct timeval *a, const struct timeval *b) PA_GCC_PURE;
 
 /** Return the time difference between now and the specified timestamp */
 pa_usec_t pa_timeval_age(const struct timeval *tv);
 
 /** Add the specified time inmicroseconds to the specified timeval structure */
-struct timeval* pa_timeval_add(struct timeval *tv, pa_usec_t v);
+struct timeval* pa_timeval_add(struct timeval *tv, pa_usec_t v) PA_GCC_PURE;
 
 PA_C_DECL_END
 
diff --git a/src/pulse/utf8.h b/src/pulse/utf8.h
index ea08840b..1e08047c 100644
--- a/src/pulse/utf8.h
+++ b/src/pulse/utf8.h
@@ -34,7 +34,7 @@
 PA_C_DECL_BEGIN
 
 /** Test if the specified strings qualifies as valid UTF8. Return the string if so, otherwise NULL */
-char *pa_utf8_valid(const char *str);
+char *pa_utf8_valid(const char *str) PA_GCC_PURE;
 
 /** Filter all invalid UTF8 characters from the specified string, returning a new fully UTF8 valid string. Don't forget to free the returned string with pa_xfree() */
 char *pa_utf8_filter(const char *str);
diff --git a/src/pulse/volume.h b/src/pulse/volume.h
index a928ff71..22e5b8a4 100644
--- a/src/pulse/volume.h
+++ b/src/pulse/volume.h
@@ -113,7 +113,7 @@ typedef struct pa_cvolume {
 } pa_cvolume;
 
 /** Return non-zero when *a == *b */
-int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b);
+int pa_cvolume_equal(const pa_cvolume *a, const pa_cvolume *b) PA_GCC_PURE;
 
 /** Set the volume of all channels to PA_VOLUME_NORM */
 #define pa_cvolume_reset(a, n) pa_cvolume_set((a), (n), PA_VOLUME_NORM)
@@ -131,13 +131,13 @@ pa_cvolume* pa_cvolume_set(pa_cvolume *a, unsigned channels, pa_volume_t v);
 char *pa_cvolume_snprint(char *s, size_t l, const pa_cvolume *c);
 
 /** Return the average volume of all channels */
-pa_volume_t pa_cvolume_avg(const pa_cvolume *a);
+pa_volume_t pa_cvolume_avg(const pa_cvolume *a) PA_GCC_PURE;
 
 /** Return TRUE when the passed cvolume structure is valid, FALSE otherwise */
-int pa_cvolume_valid(const pa_cvolume *v);
+int pa_cvolume_valid(const pa_cvolume *v) PA_GCC_PURE;
 
 /** Return non-zero if the volume of all channels is equal to the specified value */
-int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v);
+int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v) PA_GCC_PURE;
 
 /** Return 1 if the specified volume has all channels muted */
 #define pa_cvolume_is_muted(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_MUTED)
@@ -146,22 +146,22 @@ int pa_cvolume_channels_equal_to(const pa_cvolume *a, pa_volume_t v);
 #define pa_cvolume_is_norm(a) pa_cvolume_channels_equal_to((a), PA_VOLUME_NORM)
 
 /** Multiply two volumes specifications, return the result. This uses PA_VOLUME_NORM as neutral element of multiplication. This is only valid for software volumes! */
-pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b);
+pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) PA_GCC_CONST;
 
 /** Multiply to per-channel volumes and return the result in *dest. This is only valid for software volumes! */
-pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b);
+pa_cvolume *pa_sw_cvolume_multiply(pa_cvolume *dest, const pa_cvolume *a, const pa_cvolume *b) PA_GCC_PURE;
 
 /** Convert a decibel value to a volume. This is only valid for software volumes! \since 0.4 */
-pa_volume_t pa_sw_volume_from_dB(double f);
+pa_volume_t pa_sw_volume_from_dB(double f) PA_GCC_CONST;
 
 /** Convert a volume to a decibel value. This is only valid for software volumes! \since 0.4 */
-double pa_sw_volume_to_dB(pa_volume_t v);
+double pa_sw_volume_to_dB(pa_volume_t v) PA_GCC_CONST;
 
 /** Convert a linear factor to a volume. This is only valid for software volumes! \since 0.8 */
-pa_volume_t pa_sw_volume_from_linear(double v);
+pa_volume_t pa_sw_volume_from_linear(double v) PA_GCC_CONST;
 
 /** Convert a volume to a linear factor. This is only valid for software volumes! \since 0.8 */
-double pa_sw_volume_to_linear(pa_volume_t v);
+double pa_sw_volume_to_linear(pa_volume_t v) PA_GCC_CONST;
 
 #ifdef INFINITY
 #define PA_DECIBEL_MININFTY (-INFINITY)