treewide: get rid of C math function usage

src/ReplayGainGlobal.cxx

@@ -20,12 +20,12 @@
 #include "ReplayGainGlobal.hxx"
 #include "ReplayGainConfig.hxx"
 #include "config/Data.hxx"
+#include "util/Math.hxx"
 
 #include <cassert>
 #include <stdexcept>
 
 #include <stdlib.h>
-#include <math.h>
 
 static float
 ParsePreamp(const char *s)

src/ReplayGainInfo.cxx

@@ -19,8 +19,7 @@
 
 #include "ReplayGainInfo.hxx"
 #include "ReplayGainConfig.hxx"
-
-#include <math.h>
+#include "util/Math.hxx"
 
 float
 ReplayGainTuple::CalculateScale(const ReplayGainConfig &config) const noexcept

src/decoder/Bridge.cxx

@@ -37,9 +37,9 @@
 #include "util/StringBuffer.hxx"
 
 #include <cassert>
+#include <cmath>
 
 #include <string.h>
-#include <math.h>
 
 DecoderBridge::DecoderBridge(DecoderControl &_dc, bool _initial_seek_pending,
 			     std::unique_ptr<Tag> _tag) noexcept
@@ -611,7 +611,7 @@ DecoderBridge::SubmitReplayGain(const ReplayGainInfo *new_replay_gain_info) noex
 			const auto &tuple = new_replay_gain_info->Get(rgm);
 			const auto scale =
 				tuple.CalculateScale(dc.replay_gain_config);
-			dc.replay_gain_db = 20.0 * log10f(scale);
+			dc.replay_gain_db = 20.0 * std::log10(scale);
 		}
 
 		replay_gain_info = *new_replay_gain_info;

src/decoder/plugins/MpcdecDecoderPlugin.cxx

@@ -25,6 +25,7 @@
 #include "tag/Handler.hxx"
 #include "util/Domain.hxx"
 #include "util/Clamp.hxx"
+#include "util/Math.hxx"
 #include "util/ScopeExit.hxx"
 #include "Log.hxx"
 
@@ -32,8 +33,6 @@
 
 #include <iterator>
 
-#include <math.h>
-
 struct mpc_decoder_data {
 	InputStream &is;
 	DecoderClient *client;

src/mixer/plugins/AlsaMixerPlugin.cxx

@@ -26,6 +26,7 @@
 #include "event/Call.hxx"
 #include "util/ASCII.hxx"
 #include "util/Domain.hxx"
+#include "util/Math.hxx"
 #include "util/RuntimeError.hxx"
 #include "Log.hxx"
 
@@ -35,8 +36,6 @@ extern "C" {
 
 #include <alsa/asoundlib.h>
 
-#include <math.h>
-
 #define VOLUME_MIXER_ALSA_DEFAULT		"default"
 #define VOLUME_MIXER_ALSA_CONTROL_DEFAULT	"PCM"
 static constexpr unsigned VOLUME_MIXER_ALSA_INDEX_DEFAULT = 0;

src/mixer/plugins/SoftwareMixerPlugin.cxx

@@ -23,8 +23,9 @@
 #include "pcm/Volume.hxx"
 
 #include <cassert>
+#include <cmath>
 
-#include <math.h>
+#include <assert.h>
 
 class SoftwareMixer final : public Mixer {
 	Filter *filter = nullptr;
@@ -74,7 +75,7 @@ PercentVolumeToSoftwareVolume(unsigned volume) noexcept
 	if (volume >= 100)
 		return PCM_VOLUME_1;
 	else if (volume > 0)
-		return pcm_float_to_volume((exp(volume / 25.0) - 1) /
+		return pcm_float_to_volume((std::exp(volume / 25.0) - 1) /
 					   (54.5981500331F - 1));
 	else
 		return 0;

src/util/Math.hxx

@@ -31,10 +31,16 @@
 #define MATH_HXX
 
 #ifdef __UCLIBC__
+#include <boost/math/special_functions/pow.hpp>
 #include <boost/math/special_functions/round.hpp>
+using boost::math::iround;
+using boost::math::pow;
 using boost::math::lround;
+#define lrint iround
 #else
 #include <cmath>
+using std::pow;
+using std::lrint;
 using std::lround;
 #endif