error: ‘isnan’ was not declared in this scope

[Zauberfisch]

Building fails for me with the error message:

g++ -Ofast -std=c++11 -Wall -Wno-unused-function -I/usr/local/include/ -I/usr/include `pkg-config --cflags jack` `pkg-config --cflags libpulse` -c jack_volume.cpp -o jack_volume.o
jack_volume.cpp: In member function ‘void jack_volume::channel_lin(int32_t, float)’:
jack_volume.cpp:163:14: error: ‘isnan’ was not declared in this scope
   JV_ASSERT(!isnan(new_gain_lin), "new_gain_lin is not a number");
              ^~~~~
jack_volume.cpp:24:37: note: in definition of macro ‘JV_ASSERT’
 #define JV_ASSERT(cond, msg) if (! (cond)) throw std::runtime_error(msg)
                                     ^~~~
make: *** [Makefile:35: jack_volume.o] Error 1

gcc --version: gcc (GCC) 8.2.1 20181127
uname -a: Linux fishbowl-g1 4.19.13-1-MANJARO #1 SMP PREEMPT Sat Dec 29 15:43:56 UTC 2018 x86_64 GNU/Linux

Given that this is just input validation, I removed that line and was then able to compile it.

[hboetes]

According to: https://en.cppreference.com/w/c/numeric/math/isnan you have to include these headers:

#include <stdio.h>
#include <math.h>
#include <float.h>

[hboetes]

diff --git a/Makefile b/Makefile
index 71f5dac..07cdd48 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ CXXFLAGS = -Ofast -std=c++11 -Wall -Wno-unused-function
 LIBS = `pkg-config --libs jack` `pkg-config --libs libpulse` -pthread
 INCLUDE = -I/usr/local/include/ -I/usr/include `pkg-config --cflags jack` `pkg-config --cflags libpulse`
 
-GCC = g++
+CXX = c++
 
 JV_SOURCES = jack_volume.cpp
 JV_OBJS = $(JV_SOURCES:.cpp=.o) /usr/local/lib/libOSC++.a
@@ -12,24 +12,20 @@ PAV_OBJS = $(PAV_SOURCES:.cpp=.o) /usr/local/lib/libOSC++.a
 PAV_TARGET = pa-volume
 
 all: $(JV_OBJS) $(PAV_OBJS)
-	$(GCC) -o $(JV_TARGET) $(JV_OBJS) $(LIBS)
-	$(GCC) -o $(PAV_TARGET) $(PAV_OBJS) $(LIBS)
+	$(CXX) -o $(JV_TARGET) $(JV_OBJS) $(LIBS)
+	$(CXX) -o $(PAV_TARGET) $(PAV_OBJS) $(LIBS)
 
 install: $(JV_TARGET) $(PAV_TARGET)
-	cp -f $(JV_TARGET) /usr/local/bin/
-	cp -f $(PAV_TARGET) /usr/local/bin/
-	cp -f jvctl.py /usr/local/bin/jvctl
-	cp -f udp_dispatcher.py /usr/local/bin/udp_dispatcher
-	cp -f generic_connector.py /usr/local/bin/generic_connector
-	chmod a+rx /usr/local/bin/$(JV_TARGET)
-	chmod a+rx /usr/local/bin/$(PAV_TARGET)
-	chmod a+rx /usr/local/bin/jvctl
-	chmod a+rx /usr/local/bin/udp_dispatcher
-	chmod a+rx /usr/local/bin/generic_connector
+	install -d $(DESTDIR)/usr/local/bin
+	install $(JV_TARGET) $(DESTDIR)/usr/local/bin/
+	install $(PAV_TARGET) $(DESTDIR)/usr/local/bin/
+	install jvctl.py $(DESTDIR)/usr/local/bin/jvctl
+	install udp_dispatcher.py $(DESTDIR)/usr/local/bin/udp_dispatcher
+	install generic_connector.py $(DESTDIR)/usr/local/bin/generic_connector
 
 clean:
 	rm -f $(JV_SOURCES:.cpp=.o) $(JV_TARGET)
 	rm -f $(PAV_SOURCES:.cpp=.o) $(PAV_TARGET)
 
 %.o:%.cpp
-	$(GCC) $(CXXFLAGS) $(INCLUDE) -c $< -o $@
+	$(CXX) $(CXXFLAGS) $(INCLUDE) -c $< -o $@
diff --git a/jack_volume.cpp b/jack_volume.cpp
index c4f2307..d6d4086 100644
--- a/jack_volume.cpp
+++ b/jack_volume.cpp
@@ -8,6 +8,11 @@
 #include <iostream>
 #include <vector>
 #include <thread>
+
+#include <stdio.h>
+#include <math.h>
+#include <float.h>
+
 extern "C" {
 	#include <jack/jack.h>
 }

[voidseg]

Thanks for your feedback! Please confirm the fixed version in branch fix-isnan.

Best regards
voidseg

[Zauberfisch]

sorry, I'm not gonna be able to test it at this time. Perhaps @hboetes could test it?

[hboetes]

I already tested it, it's simply the patch I suggested.