xref: /freebsd/sys/contrib/openzfs/config/find_system_library.m4 (revision b985c9cafd2aedac5cf92428c0211485ea4ede24)
1# find_system_lib.m4 - Macros to search for a system library.   -*- Autoconf -*-
2
3dnl requires pkg.m4 from pkg-config
4dnl requires ax_save_flags.m4 from autoconf-archive
5dnl requires ax_restore_flags.m4 from autoconf-archive
6
7dnl ZFS_AC_FIND_SYSTEM_LIBRARY(VARIABLE-PREFIX, MODULE, HEADER, HEADER-PREFIXES, LIBRARY, FUNCTIONS, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
8
9AC_DEFUN([ZFS_AC_FIND_SYSTEM_LIBRARY], [
10    AC_REQUIRE([PKG_PROG_PKG_CONFIG])
11
12    _header_found=
13    _library_found=
14    _pc_found=
15
16    AS_IF([test -n "$2"], [PKG_CHECK_MODULES([$1], [$2], [
17	_header_found=1
18	_library_found=1
19	_pc_found=1
20    ], [:])])
21
22    # set _header_found/_library_found if the user passed in CFLAGS/LIBS
23    AS_IF([test "x$[$1][_CFLAGS]" != x], [_header_found=1])
24    AS_IF([test "x$[$1][_LIBS]" != x], [_library_found=1])
25
26    AX_SAVE_FLAGS
27
28    orig_CFLAGS="$CFLAGS"
29
30    for _prefixdir in /usr /usr/local
31    do
32	AS_VAR_PUSHDEF([header_cache], [ac_cv_header_$3])
33	AS_IF([test "x$_prefixdir" != "x/usr"], [
34	    [$1][_CFLAGS]="-I$lt_sysroot$_prefixdir/include"
35	    AS_IF([test "x$_library_found" = x], [
36		[$1][_LIBS]="-L$lt_sysroot$_prefixdir/lib"
37	    ])
38	])
39	CFLAGS="$orig_CFLAGS $[$1][_CFLAGS]"
40	AS_UNSET([header_cache])
41	AC_CHECK_HEADER([$3], [
42	    _header_found=1
43	    break
44	], [AS_IF([test "x$_header_found" = "x1"], [
45	    # if pkg-config or the user set CFLAGS, fail if the header is unusable
46	    AC_MSG_FAILURE([header [$3] for library [$5] is not usable])
47	])], [AC_INCLUDES_DEFAULT])
48	# search for header under HEADER-PREFIXES
49	m4_foreach_w([prefix], [$4], [
50	    [$1][_CFLAGS]=["-I$lt_sysroot$_prefixdir/include/]prefix["]
51	    CFLAGS="$orig_CFLAGS $[$1][_CFLAGS]"
52	    AS_UNSET([header_cache])
53	    AC_CHECK_HEADER([$3], [
54		_header_found=1
55		break
56	    ], [], [AC_INCLUDES_DEFAULT])
57	])
58	AS_VAR_POPDEF([header_cache])
59    done
60
61    AS_IF([test "x$_header_found" = "x1"], [
62	AS_IF([test "x$_library_found" = x], [
63	    [$1][_LIBS]="$[$1]_LIBS -l[$5]"
64	])
65	LDFLAGS="$LDFLAGS $[$1][_LIBS]"
66
67	_libcheck=1
68	m4_ifval([$6],
69	    [m4_foreach_w([func], [$6], [AC_CHECK_LIB([$5], func, [:], [_libcheck=])])],
70	    [AC_CHECK_LIB([$5], [main], [:], [_libcheck=])])
71
72	AS_IF([test "x$_libcheck" = "x1"], [_library_found=1],
73	    [test "x$_library_found" = "x1"], [
74	    # if pkg-config or the user set LIBS, fail if the library is unusable
75	    AC_MSG_FAILURE([library [$5] is not usable])
76	])
77    ], [test "x$_library_found" = "x1"], [
78	# if the user set LIBS, fail if we didn't find the header
79	AC_MSG_FAILURE([cannot find header [$3] for library [$5]])
80    ])
81
82    AX_RESTORE_FLAGS
83
84    AS_IF([test "x$_header_found" = "x1" && test "x$_library_found" = "x1"], [
85	AC_SUBST([$1]_CFLAGS)
86	AC_SUBST([$1]_LIBS)
87	AS_IF([test "x$_pc_found" = "x1"], [
88	    AC_SUBST([$1]_PC, [$2])
89	])
90	AC_DEFINE([HAVE_][$1], [1], [Define if you have [$5]])
91	$7
92    ],[dnl ELSE
93	AC_SUBST([$1]_CFLAGS, [""])
94	AC_SUBST([$1]_LIBS, [""])
95	AC_MSG_WARN([cannot find [$5] via pkg-config or in the standard locations])
96	$8
97    ])
98])
99