gcc/testsuite/gcc.dg/cpp/cmdlne-dU-18.c - gcc - Git at Google

 /* { dg-do preprocess } */
 /* { dg-options "-nostdinc -P -dU" } */
 /* { dg-final { scan-file cmdlne-dU-18.i "^\n*x 1 y\n+#define A 1\n*$" } } */
 #define A 1
 x A y
	/* { dg-do preprocess } */
	/* { dg-options "-nostdinc -P -dU" } */
	/* { dg-final { scan-file cmdlne-dU-18.i "^\nx 1 y\n+#define A 1\n$" } } */
	#define A 1
	x A y