1 dnl @synopsis AC_C_DEPEND_FLAG
3 dnl define C_DEPEND_FLAG
4 dnl define CXX_DEPEND_FLAG
7 dnl @author Marc Tajchman
9 AC_DEFUN(AC_DEPEND_FLAG,
10 [AC_CACHE_CHECK(which flag for dependency information generation,
14 echo "conftest.o: conftest.c" > conftest.verif
15 echo "int main() { return 0; }" > conftest.c
18 for ac_C_DEPEND_FLAG in -xM -MM -M ; do
20 rm -f conftest.d conftest.err
21 ${CC-cc} ${ac_C_DEPEND_FLAG} -c conftest.c 1> conftest.d 2> conftest.err
22 if test -f conftest.u ; then
23 mv conftest.u conftest.d
27 diff -b -B conftest.d conftest.verif > conftest
28 if test ! -s conftest ; then
29 C_DEPEND_FLAG=${ac_C_DEPEND_FLAG}
34 dnl use gcc option -MG : asume unknown file will be construct later
35 rm -f conftest.d conftest.err
36 ${CC-cc} ${C_DEPEND_FLAG} -MG -c conftest.c 1> conftest.d 2> conftest.err
37 if test -f conftest.u ; then
38 mv conftest.u conftest.d
41 diff -b -B conftest.d conftest.verif > conftest
42 if test ! -s conftest ; then
43 C_DEPEND_FLAG=${C_DEPEND_FLAG}" -MG"
47 if test "x${C_DEPEND_FLAG}" = "x" ; then
48 echo "cannot determine flag (C language)"
52 echo -n " C : " ${C_DEPEND_FLAG}
55 echo "conftest.o: conftest.cxx" > conftest.verif
56 echo "int main() { return 0; }" > conftest.cxx
59 for ac_CXX_DEPEND_FLAG in -xM -MM -M ; do
61 rm -f conftest.d conftest.err
62 ${CXX-c++} ${ac_CXX_DEPEND_FLAG} -c conftest.cxx 1> conftest.d 2> conftest.err
63 if test -f conftest.u ; then
64 mv conftest.u conftest.d
68 diff -b -B conftest.d conftest.verif > conftest
69 if test ! -s conftest ; then
70 CXX_DEPEND_FLAG=${ac_CXX_DEPEND_FLAG}
75 dnl use g++ option -MG : asume unknown file will be construct later
76 rm -f conftest.d conftest.err
77 ${CXX-c++} ${CXX_DEPEND_FLAG} -MG -c conftest.cxx 1> conftest.d 2> conftest.err
78 if test -f conftest.u ; then
79 mv conftest.u conftest.d
82 diff -b -B conftest.d conftest.verif > conftest
83 if test ! -s conftest ; then
84 CXX_DEPEND_FLAG=${CXX_DEPEND_FLAG}" -MG"
89 if test "x${CXX_DEPEND_FLAG}" = "x" ; then
90 echo "cannot determine flag (C++ language)"
94 echo -n " C++ : " ${CXX_DEPEND_FLAG}
97 AC_SUBST(C_DEPEND_FLAG)
98 AC_SUBST(CXX_DEPEND_FLAG)