There is a command like 'g++ -nostartfiles -Wl,--start-group arduino.ar -lc -Wl,--end-group ...' would go wrong. `-nostartfiles` makes libc needs some implements like _init in arduino.ar, but also arduino.ar depends on libc too. G++ will output an error 'FAIL: undefined reference to _init' when g++ removes the `-lc`. Jonathan Wakely <jwakely.gcc@xxxxxxxxx> 於 2021年2月25日 週四 下午3:23寫道： > > > On Thu, 25 Feb 2021, 02:46 Yeting Kuo via Gcc-help, <gcc-help@xxxxxxxxxxx> > wrote: > >> Hi all, >> I have a compiler driver issue when using g++. I want to check whether it >> is a bug. >> I send '-Wl,--start-group x.o -lc -Wl,--end-group' to g++, but the command >> collect2 received is '--start-group x.o --end-group' like the following >> commands: >> > > > Does it cause a problem? The g++ driver automatically links to libstdc++ > and that depends on libc, so the -lc argument has to be after -lstdc++. > Otherwise for static linking the linker could open libc.a before it knows > about the symbols that libstdc++.a needs from it. > > > >
