Linux/MacOSX: Better approach to avoid that jitterentropy code is optimized by the compiler

src/Build/Include/Makefile.inc

@@ -14,12 +14,16 @@ $(NAME): $(NAME).a
 
 clean:
 	@echo Cleaning $(NAME)
-	rm -f $(APPNAME) $(NAME).a $(OBJS) $(OBJSEX) $(OBJS:.o=.d) *.gch
+	rm -f $(APPNAME) $(NAME).a $(OBJS) $(OBJSEX) $(OBJSNOOPT) $(OBJS:.o=.d) $(OBJSEX:.oo=.d) $(OBJSNOOPT:.o0=.d) *.gch
 
 %.o: %.c
 	@echo Compiling $(<F)
 	$(CC) $(CFLAGS) -c $< -o $@
 
+%.o0: %.c
+	@echo Compiling $(<F)
+	$(CC) $(CFLAGS) -O0 -c $< -o $@
+
 %.o: %.cpp
 	@echo Compiling $(<F)
 	$(CXX) $(CXXFLAGS) -c $< -o $@
@@ -64,10 +68,10 @@ TR_SED_BIN := tr '\n' ' ' | tr -s ' ' ',' | sed -e 's/^,//g' -e 's/,$$/n/' | tr
 
 
 # Dependencies
--include $(OBJS:.o=.d) $(OBJSEX:.oo=.d)
+-include $(OBJS:.o=.d) $(OBJSEX:.oo=.d) $(OBJSNOOPT:.o0=.d)
 
 
-$(NAME).a: $(OBJS) $(OBJSEX)
+$(NAME).a: $(OBJS) $(OBJSEX) $(OBJSNOOPT)
 	@echo Updating library $@
-	$(AR) $(AFLAGS) -rcu $@ $(OBJS) $(OBJSEX)
+	$(AR) $(AFLAGS) -rcu $@ $(OBJS) $(OBJSEX) $(OBJSNOOPT)
 	$(RANLIB) $@

src/Crypto/jitterentropy-base.c

@@ -57,7 +57,11 @@
 #pragma optimize( "", off )
 #pragma warning(disable:4242 4244 4334) /* disable warnings on the original code */
 #else
-#pragma GCC optimize ("O0")
+#if defined(__clang__)
+	#pragma clang optimize off
+#elif defined (__GNUC__)
+	#pragma GCC optimize ("O0")
+#endif
 #endif
 
 #include "jitterentropy.h"

src/Volume/Volume.make

@@ -12,6 +12,7 @@
 
 OBJS :=
 OBJSEX :=
+OBJSNOOPT :=
 OBJS += Cipher.o
 OBJS += EncryptionAlgorithm.o
 OBJS += EncryptionMode.o
@@ -80,7 +81,8 @@ OBJS += ../Crypto/GostCipher.o
 OBJS += ../Crypto/Streebog.o
 OBJS += ../Crypto/kuznyechik.o
 OBJS += ../Crypto/kuznyechik_simd.o
-OBJS += ../Crypto/jitterentropy-base.o
+
+OBJSNOOPT += ../Crypto/jitterentropy-base.o0
 
 OBJS += ../Common/Crc.o
 OBJS += ../Common/Endian.o