xor4, rotl, sha256_forward unused functions [-Wunused-function]

[Geremia]

bash make.sh

throws these warnings

main.cc:471:13: warning: ‘void xor4(int*, int*, int*, int*, int*)’ defined but not used [-Wunused-function]                   
 static void xor4(int r[32], int a[32], int b[32], int c[32], int d[32])                                                      
             ^                                                                                                                
main.cc:707:13: warning: ‘void rotl(int*, int*, unsigned int)’ defined but not used [-Wunused-function]                       
 static void rotl(int r[32], int x[32], unsigned int n)                                                                       
             ^                                                                                                                
main.cc:1071:17: warning: ‘uint32_t rotl(uint32_t, unsigned int)’ defined but not used [-Wunused-function]                    
 static uint32_t rotl(uint32_t x, unsigned int n)                                                                             
                 ^                                                                                                            
main.cc:1076:13: warning: ‘void sha256_forward(uint8_t*, int, uint32_t*)’ defined but not used [-Wunused-function]            
 static void sha256_forward(uint8_t Message_Block[64], int len, uint32_t h_out[8])                                            
             ^