/tmp/ccJDHjza.o: In function `main':
foo.cc:(.text.startup+0x35): relocation truncated to fit: R_X86_64_PC32 against symbol `a' defined in .bss section in /tmp/ccJDHjza.o
/tmp/ccJDHjza.o: In function `_GLOBAL__sub_I_a':
foo.cc:(.text.startup+0x1f3): relocation truncated to fit: R_X86_64_PC32 against `.bss'
foo.cc:(.text.startup+0x211): relocation truncated to fit: R_X86_64_PC32 against `.bss'
collect2: error: ld returned 1 exit status