We need to use AC_CHECK_TOOL to check for cpp in order to support

configure

@@ -311,7 +311,7 @@ ac_includes_default="\
 # include <unistd.h>
 #endif"
 
-ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS WIN16_FILES WIN16_INSTALL build build_cpu build_vendor build_os host host_cpu host_vendor host_os SET_MAKE CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT CXX CXXFLAGS ac_ct_CXX CPP TOOLSDIR X_CFLAGS X_PRE_LIBS X_LIBS X_EXTRA_LIBS YACC LEX LEXLIB LEX_OUTPUT_ROOT XYACC XLEX AS ac_ct_AS LD ac_ct_LD AR ac_ct_AR RANLIB ac_ct_RANLIB STRIP ac_ct_STRIP WINDRES ac_ct_WINDRES LN_S LN LDCONFIG INSTALL_PROGRAM INSTALL_SCRIPT INSTALL_DATA LINT LINTFLAGS DB2HTML DB2PDF DB2PS DB2TXT LIBPTHREAD JPEGLIB EGREP GIFLIB XLIB XFILES OPENGLFILES GLU32FILES OPENGL_LIBS GLUT_LIBS GLUT32FILES NASLIBS CURSESLIBS sane_devel SANELIBS SANEINCL ICULIBS ft_devel ft_devel2 FREETYPEINCL ARTSCCONFIG ARTSLIBS ARTSINCL ALSALIBS AUDIOIOLIBS CAPI4LINUXLIBS EXTRACFLAGS DLLEXT DLLFLAGS DLLIBS LDSHARED LDDLLFLAGS LIBEXT IMPLIBEXT DLLTOOL ac_ct_DLLTOOL DLLWRAP ac_ct_DLLWRAP LDEXECFLAGS CROSSTEST CROSSCC CROSSWINDRES LDPATH CRTLIBS WINE_BINARIES MAIN_BINARY LDD ALLOCA LIBOBJS LTLIBOBJS'
+ac_subst_vars='SHELL PATH_SEPARATOR PACKAGE_NAME PACKAGE_TARNAME PACKAGE_VERSION PACKAGE_STRING PACKAGE_BUGREPORT exec_prefix prefix program_transform_name bindir sbindir libexecdir datadir sysconfdir sharedstatedir localstatedir libdir includedir oldincludedir infodir mandir build_alias host_alias target_alias DEFS ECHO_C ECHO_N ECHO_T LIBS WIN16_FILES WIN16_INSTALL build build_cpu build_vendor build_os host host_cpu host_vendor host_os SET_MAKE CC CFLAGS LDFLAGS CPPFLAGS ac_ct_CC EXEEXT OBJEXT CXX CXXFLAGS ac_ct_CXX CPP ac_ct_CPP TOOLSDIR X_CFLAGS X_PRE_LIBS X_LIBS X_EXTRA_LIBS YACC LEX LEXLIB LEX_OUTPUT_ROOT XYACC XLEX AS ac_ct_AS LD ac_ct_LD AR ac_ct_AR RANLIB ac_ct_RANLIB STRIP ac_ct_STRIP WINDRES ac_ct_WINDRES LN_S LN LDCONFIG INSTALL_PROGRAM INSTALL_SCRIPT INSTALL_DATA LINT LINTFLAGS DB2HTML DB2PDF DB2PS DB2TXT LIBPTHREAD JPEGLIB EGREP GIFLIB XLIB XFILES OPENGLFILES GLU32FILES OPENGL_LIBS GLUT_LIBS GLUT32FILES NASLIBS CURSESLIBS sane_devel SANELIBS SANEINCL ICULIBS ft_devel ft_devel2 FREETYPEINCL ARTSCCONFIG ARTSLIBS ARTSINCL ALSALIBS AUDIOIOLIBS CAPI4LINUXLIBS EXTRACFLAGS DLLEXT DLLFLAGS DLLIBS LDSHARED LDDLLFLAGS LIBEXT IMPLIBEXT DLLTOOL ac_ct_DLLTOOL DLLWRAP ac_ct_DLLWRAP LDEXECFLAGS CROSSTEST CROSSCC CROSSWINDRES LDPATH CRTLIBS WINE_BINARIES MAIN_BINARY LDD ALLOCA LIBOBJS LTLIBOBJS'
 ac_subst_files='MAKE_RULES MAKE_DLL_RULES MAKE_TEST_RULES MAKE_LIB_RULES MAKE_PROG_RULES'
 
 # Initialize some variables set by options.
@@ -2782,8 +2782,9 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
 ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
-# Extract the first word of ""cpp"", so it can be a program name with args.
-set dummy "cpp"; ac_word=$2
+if test -n "$ac_tool_prefix"; then
+  # Extract the first word of "${ac_tool_prefix}cpp", so it can be a program name with args.
+set dummy ${ac_tool_prefix}cpp; ac_word=$2
 echo "$as_me:$LINENO: checking for $ac_word" >&5
 echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
 if test "${ac_cv_prog_CPP+set}" = set; then
@@ -2799,7 +2800,7 @@ do
   test -z "$as_dir" && as_dir=.
   for ac_exec_ext in '' $ac_executable_extensions; do
   if $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
-    ac_cv_prog_CPP=""cpp""
+    ac_cv_prog_CPP="${ac_tool_prefix}cpp"
     echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
     break 2
   fi
@@ -2817,6 +2818,50 @@ else
 echo "${ECHO_T}no" >&6
 fi
 
+fi
+if test -z "$ac_cv_prog_CPP"; then
+  ac_ct_CPP=$CPP
+  # Extract the first word of "cpp", so it can be a program name with args.
+set dummy cpp; ac_word=$2
+echo "$as_me:$LINENO: checking for $ac_word" >&5
+echo $ECHO_N "checking for $ac_word... $ECHO_C" >&6
+if test "${ac_cv_prog_ac_ct_CPP+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  if test -n "$ac_ct_CPP"; then
+  ac_cv_prog_ac_ct_CPP="$ac_ct_CPP" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+  for ac_exec_ext in '' $ac_executable_extensions; do
+  if $as_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_ac_ct_CPP="cpp"
+    echo "$as_me:$LINENO: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+done
+
+  test -z "$ac_cv_prog_ac_ct_CPP" && ac_cv_prog_ac_ct_CPP="cpp"
+fi
+fi
+ac_ct_CPP=$ac_cv_prog_ac_ct_CPP
+if test -n "$ac_ct_CPP"; then
+  echo "$as_me:$LINENO: result: $ac_ct_CPP" >&5
+echo "${ECHO_T}$ac_ct_CPP" >&6
+else
+  echo "$as_me:$LINENO: result: no" >&5
+echo "${ECHO_T}no" >&6
+fi
+
+  CPP=$ac_ct_CPP
+else
+  CPP="$ac_cv_prog_CPP"
+fi
+
 
 echo "$as_me:$LINENO: checking for the directory containing the Wine tools" >&5
 echo $ECHO_N "checking for the directory containing the Wine tools... $ECHO_C" >&6
@@ -20111,6 +20156,7 @@ s,@CXX@,$CXX,;t t
 s,@CXXFLAGS@,$CXXFLAGS,;t t
 s,@ac_ct_CXX@,$ac_ct_CXX,;t t
 s,@CPP@,$CPP,;t t
+s,@ac_ct_CPP@,$ac_ct_CPP,;t t
 s,@TOOLSDIR@,$TOOLSDIR,;t t
 s,@X_CFLAGS@,$X_CFLAGS,;t t
 s,@X_PRE_LIBS@,$X_PRE_LIBS,;t t

configure.ac

@@ -43,7 +43,7 @@ AC_PROG_MAKE_SET
 AC_PROG_CC
 AC_PROG_CXX
 dnl We can't use AC_PROG_CPP, it uses by default $(CC) -E
-AC_CHECK_PROG(CPP, "cpp", "cpp")
+AC_CHECK_TOOL(CPP,cpp,cpp)
 
 AC_CACHE_CHECK([for the directory containing the Wine tools], wine_cv_toolsdir,
   [if test -z "$with_wine_tools"; then