foo.cc: In function 'int x(int)':
foo.cc:8:7: warning: variable 'b' set but not used [-Wunused-but-set-variable]
    8 |   int b=1;
      |       ^
foo.cc:15:1: warning: control reaches end of non-void function [-Wreturn-type]
   15 | }
      | ^

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