* tests/atconfig.in (CPPFLAGS): Add.

* tests/calc.at (AT_CHECK): Use CPPFLAGS.

tests/atconfig.in

@@ -85,6 +85,7 @@ M4='@M4@'
 # We need a C compiler.
 CC='@CC@'
 CFLAGS='@CFLAGS@'
+CPPFLAGS='-I$(top_srcdir) @CPPFLAGS@'
 
 # We want to use the files shipped with Bison.
 BISON_SIMPLE=$at_top_srcdir/src/bison.simple

tests/calc.at

@@ -293,7 +293,7 @@ AT_DATA_CALC_Y([$1])
 # Specify the output files to avoid problems on different file systems.
 AT_CHECK([bison calc.y -o calc.c patsubst([$1], [--yyerror-verbose])],
          [0], [], [])
-AT_CHECK([$CC $CFLAGS calc.c -o calc], 0, [], [])
+AT_CHECK([$CC $CFLAGS $CPPFLAGS calc.c -o calc], 0, [], [])
 
 # Test the priorities.
 _AT_CHECK_CALC([$1],