/in/foo.cc: In function 'void calc()':
/in/foo.cc:12:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s2);
     ^~~~
In file included from /in/foo.cc:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:12:12: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s2);
            ^
In file included from /in/foo.cc:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:13:5: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s2);
     ^~~~
In file included from /in/foo.cc:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:13:12: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
     gets(s2);
            ^
In file included from /in/foo.cc:1:0:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/tmp/cc2zM3DS.o: In function `calc()':
foo.cc:(.text+0x26): warning: the `gets' function is dangerous and should not be used.
foo.cc:(.text+0x21): relocation truncated to fit: R_X86_64_PC32 against symbol `s2' defined in .bss section in /tmp/cc2zM3DS.o
foo.cc:(.text+0x2d): relocation truncated to fit: R_X86_64_PC32 against symbol `s2' defined in .bss section in /tmp/cc2zM3DS.o
foo.cc:(.text+0x39): relocation truncated to fit: R_X86_64_PC32 against symbol `s1' defined in .bss section in /tmp/cc2zM3DS.o
foo.cc:(.text+0x74): relocation truncated to fit: R_X86_64_PC32 against symbol `s2' defined in .bss section in /tmp/cc2zM3DS.o
foo.cc:(.text+0xd5): relocation truncated to fit: R_X86_64_PC32 against symbol `s1' defined in .bss section in /tmp/cc2zM3DS.o
/tmp/cc2zM3DS.o: In function `main':
foo.cc:(.text.startup+0x4): relocation truncated to fit: R_X86_64_PC32 against symbol `s1' defined in .bss section in /tmp/cc2zM3DS.o
/tmp/cc2zM3DS.o: In function `_GLOBAL__sub_I_s1':
foo.cc:(.text.startup+0x33): relocation truncated to fit: R_X86_64_PC32 against `.bss'
foo.cc:(.text.startup+0x51): relocation truncated to fit: R_X86_64_PC32 against `.bss'
collect2: error: ld returned 1 exit status