text: /* n_25.c:  Macro arguments are pre-expanded (unless the argument is an
      operand of # or ## operator) separately, that is, are macro-replaced
      completely prior to rescanning. */
  
  #define MACRO_0         0
  #define MACRO_1         1
  #define ZERO_TOKEN
  #define TWO_ARGS        a,b
  #define sub( x, y)      (x - y)
  #define glue( a, b)     a ## b
  #define xglue( a, b)    glue( a, b)
  #define str( a)         # a
  
  /* 25.1:    "TWO_ARGS" is read as one argument to "sub" then expanded to
          "a,b", then "x" is substituted by "a,b".    */
  /*  (a,b - 1);  */
      sub( TWO_ARGS, 1);
  
  /* 25.2:    An argument pre-expanded to 0-token.    */
  /*  ( - 1); */
      sub( ZERO_TOKEN, 1);
  
  /* 25.3:    "glue( a, b)" is pre-expanded.  */
  /*  abc;    */
      xglue( glue( a, b), c);
  
  /* 25.4:    Operands of ## operator are not pre-expanded.   */
  /*  MACRO_0MACRO_1; */
      glue( MACRO_0, MACRO_1);
  
  /* 25.5:    Operand of # operator is not pre-expanded.  */
  /*  "ZERO_TOKEN";   */
  #define ZERO_TOKEN
      str( ZERO_TOKEN);
  
  /* { dg-do preprocess }
     { dg-final { if ![file exist n_25.i] { return }                      } }
     { dg-final { if \{ [grep n_25.i "\\( *a *, *b *- *1 *\\)"] != "" \} \{ } }
     { dg-final { if \{ [grep n_25.i "\\( *- *1 *\\)"] != ""      \} \{   } }
     { dg-final { if \{ [grep n_25.i "abc"] != ""                 \} \{   } }
     { dg-final { if \{ [grep n_25.i "MACRO_0MACRO_1"] != ""      \} \{   } }
     { dg-final { if \{ [grep n_25.i "\"ZERO_TOKEN\""] != ""      \} \{   } }
     { dg-final { return \} \} \} \} \}                                   } }
     { dg-final { fail "n_25.c: pre-expansion of macro arguments"         } }
   */
  
  