Return NULL for policies that do not allow any exits
[tor/rransom.git] / acinclude.m4
blob9ae9f6dcebdf8942821a159ed3aae3bd77ddaf75
1 dnl $Id$
2 dnl Helper macros for Tor configure.in
3 dnl Copyright (c) 2001-2004, Roger Dingledine
4 dnl Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson
5 dnl Copyright (c) 2007-2008, Roger Dingledine, Nick Mathewson
6 dnl See LICENSE for licensing information
8 AC_DEFUN([TOR_EXTEND_CODEPATH],
10   if test -d "$1/lib"; then
11     LDFLAGS="-L$1/lib $LDFLAGS"
12   else
13     LDFLAGS="-L$1 $LDFLAGS"
14   fi
15   if test -d "$1/include"; then
16     CPPFLAGS="-I$1/include $CPPFLAGS"
17   else
18     CPPFLAGS="-I$1 $CPPFLAGS"
19   fi
22 AC_DEFUN([TOR_DEFINE_CODEPATH],
24   if test x$1 = "x(system)"; then
25     TOR_LDFLAGS_$2=""
26     TOR_CPPFLAGS_$2=""
27   else
28    if test -d "$1/lib"; then
29      TOR_LDFLAGS_$2="-L$1/lib"
30    else
31      TOR_LDFLAGS_$2="-L$1"
32    fi
33    if test -d "$1/include"; then
34      TOR_CPPFLAGS_$2="-I$1/include"
35    else
36      TOR_CPPFLAGS_$2="-I$1"
37    fi
38   fi
39   AC_SUBST(TOR_CPPFLAGS_$2)
40   AC_SUBST(TOR_LDFLAGS_$2)
43 dnl 1:libname
44 AC_DEFUN([TOR_WARN_MISSING_LIB], [
45 h=""
46 if test x$2 = xdevpkg; then
47   h=" headers for"
49 if test -f /etc/debian_version && test x"$tor_$1_$2_debian" != x; then
50   AC_WARN([On Debian, you can install$h $1 using "apt-get install $tor_$1_$2_debian"])
51   if test x"$tor_$1_$2_debian" != x"$tor_$1_devpkg_debian"; then 
52     AC_WARN([   You will probably need $tor_$1_devpkg_debian too.])
53   fi 
55 if test -f /etc/fedora-release && test x"$tor_$1_$2_redhat" != x; then
56   AC_WARN([On Fedora Core, you can install$h $1 using "yum install $tor_$1_$2_redhat"])
57   if test x"$tor_$1_$2_redhat" != x"$tor_$1_devpkg_redhat"; then 
58     AC_WARN([   You will probably need to install $tor_$1_devpkg_redhat too.])
59   fi 
60 else
61   if test -f /etc/redhat-release && test x"$tor_$1_$2_redhat" != x; then
62     AC_WARN([On most Redhat-based systems, you can get$h $1 by installing the $tor_$1_$2_redhat" RPM package])
63     if test x"$tor_$1_$2_redhat" != x"$tor_$1_devpkg_redhat"; then 
64       AC_WARN([   You will probably need to install $tor_$1_devpkg_redhat too.])
65     fi 
66   fi
70 dnl Look for a library, and its associated includes, and how to link
71 dnl against it.
72 dnl
73 dnl TOR_SEARCH_LIBRARY(1:libname, 2:IGNORED, 3:linkargs, 4:headers,
74 dnl                    5:prototype,
75 dnl                    6:code, 7:optionname, 8:searchextra)
76 AC_DEFUN([TOR_SEARCH_LIBRARY], [
77 try$1dir=""
78 AC_ARG_WITH($1-dir,
79   [  --with-$1-dir=PATH    Specify path to $1 installation ],
80   [
81      if test x$withval != xno ; then
82         try$1dir="$withval"
83      fi
84   ])
85 tor_saved_LIBS="$LIBS"
86 tor_saved_LDFLAGS="$LDFLAGS"
87 tor_saved_CPPFLAGS="$CPPFLAGS"
88 AC_CACHE_CHECK([for $1 directory], tor_cv_library_$1_dir, [
89   tor_$1_dir_found=no
90   tor_$1_any_linkable=no
92   for tor_trydir in "$try$1dir" "(system)" "$prefix" /usr/local /usr/pkg $8; do
93     LDFLAGS="$tor_saved_LDFLAGS"
94     LIBS="$tor_saved_LIBS $3"
95     CPPFLAGS="$tor_saved_CPPFLAGS"
97     if test -z "$tor_trydir" ; then
98       continue;
99     fi
101     # Skip the directory if it isn't there.
102     if test ! -d "$tor_trydir" && test "$tor_trydir" != "(system)"; then
103       continue;
104     fi
106     # If this isn't blank, try adding the directory (or appropriate
107     # include/libs subdirectories) to the command line.
108     if test "$tor_trydir" != "(system)"; then
109       TOR_EXTEND_CODEPATH($tor_trydir)
110     fi
112     # Can we link against (but not necessarily run, or find the headers for)
113     # the binary?
114     AC_LINK_IFELSE(AC_LANG_PROGRAM([$5], [$6]),
115                    [linkable=yes], [linkable=no])
117     if test "$linkable" = yes; then
118       tor_$1_any_linkable=yes
119       # Okay, we can link against it.  Can we find the headers?
120       AC_COMPILE_IFELSE(AC_LANG_PROGRAM([$4], [$6]),
121                         [buildable=yes], [buildable=no])
122       if test "$buildable" = yes; then
123          tor_cv_library_$1_dir=$tor_trydir
124          tor_$1_dir_found=yes
125          break
126       fi
127     fi
128   done
130   if test "$tor_$1_dir_found" = no; then
131     if test "$tor_$1_any_linkable" = no ; then
132       AC_MSG_WARN([Could not find a linkable $1.  If you have it installed somewhere unusal, you can specify an explicit path using $7])
133       TOR_WARN_MISSING_LIB($1, pkg)
134       AC_MSG_ERROR([Missing libraries; unable to proceed.])
135     else
136       AC_MSG_WARN([We found the libraries for $1, but we could not find the C header files.  You may need to install a devel package.])
137       TOR_WARN_MISSING_LIB($1, devpkg)
138       AC_MSG_ERROR([Missing headers; unable to proceed.])
139     fi
140   fi
142   LDFLAGS="$tor_saved_LDFLAGS"
143   LIBS="$tor_saved_LIBS"
144   CPPFLAGS="$tor_saved_CPPFLAGS"
145 ]) dnl end cache check
147 LIBS="$LIBS $3"
148 if test "$tor_cv_library_$1_dir" != "(system)"; then
149    TOR_EXTEND_CODEPATH($tor_cv_library_$1_dir)
152 TOR_DEFINE_CODEPATH($tor_cv_library_$1_dir, $1)
154 if test "$cross_compiling" != yes; then
155   AC_CACHE_CHECK([whether we need extra options to link $1],
156                  tor_cv_library_$1_linker_option, [
157    orig_LDFLAGS="$LDFLAGS"
158    runs=no
159    linked_with=nothing
160    if test -d "$tor_cv_library_$1_dir/lib"; then
161      tor_trydir="$tor_cv_library_$1_dir/lib"
162    else
163      tor_trydir="$tor_cv_library_$1_dir"
164    fi
165    for tor_tryextra in "(none)" "-Wl,-R$tor_trydir" "-R$tor_trydir" \
166                        "-Wl,-rpath,$tor_trydir" ; do
167      if test "$tor_tryextra" = "(none)"; then
168        LDFLAGS="$orig_LDFLAGS"
169      else
170        LDFLAGS="$tor_tryextra $orig_LDFLAGS"
171      fi
172      AC_RUN_IFELSE(AC_LANG_PROGRAM([$5], [$6]),
173                    [runnable=yes], [runnable=no])
174      if test "$runnable" = yes; then
175         tor_cv_library_$1_linker_option=$tor_tryextra
176         break
177      fi
178    done
180    if test "$runnable" = no; then
181      AC_MSG_ERROR([Found linkable $1 in $tor_cv_library_$1_dir, but it does not seem to run, even with -R. Maybe specify another using $7}])
182    fi
183    LDFLAGS="$orig_LDFLAGS"
184   ]) dnl end cache check check for extra options.
186   if test "$tor_cv_library_$1_linker_option" != "(none)" ; then
187     TOR_LDFLAGS_$1="$TOR_LDFLAGS_$1 $tor_cv_library_$1_linker_option"
188   fi
189 fi # cross-compile
191 LIBS="$tor_saved_LIBS"
192 LDFLAGS="$tor_saved_LDFLAGS"
193 CPPFLAGS="$tor_saved_CPPFLAGS"
195 ]) dnl end defun
197 dnl Check whether the prototype for a function is present or missing.
198 dnl Apple has a nasty habit of putting functions in their libraries (so that
199 dnl AC_CHECK_FUNCS passes) but not actually declaring them in the headers.
201 dnl TOR_CHECK_PROTYPE(1:functionname, 2:macroname, 2: includes)
202 AC_DEFUN([TOR_CHECK_PROTOTYPE], [
203  AC_CACHE_CHECK([for declaration of $1], tor_cv_$1_declared, [
204    AC_COMPILE_IFELSE(AC_LANG_PROGRAM([$3],[void *ptr= $1 ;]),
205                      tor_cv_$1_declared=yes,tor_cv_$1_declared=no)])
206 if test x$tor_cv_$1_declared != xno ; then
207   AC_DEFINE($2, 1,
208        [Defined if the prototype for $1 seems to be present.])