foo.c: In function 'main':
foo.c:9:11: error: 'n' undeclared (first use in this function)
    9 |     for(; n; )
      |           ^
foo.c:9:11: note: each undeclared identifier is reported only once for each function it appears in
foo.c:9:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    9 |     for(; n; )
      |     ^~~
foo.c:11:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   11 |                 printf("\n");
      |                 ^~~~~~

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