diff options
Diffstat (limited to 'm4/stl_hash.m4')
-rw-r--r-- | m4/stl_hash.m4 | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/m4/stl_hash.m4 b/m4/stl_hash.m4 new file mode 100644 index 00000000..0722b14a --- /dev/null +++ b/m4/stl_hash.m4 @@ -0,0 +1,72 @@ +# We check two things: where the include file is for +# unordered_map/hash_map (we prefer the first form), and what +# namespace unordered/hash_map lives in within that include file. We +# include AC_TRY_COMPILE for all the combinations we've seen in the +# wild. We define HASH_MAP_H to the location of the header file, and +# HASH_NAMESPACE to the namespace the class (unordered_map or +# hash_map) is in. We define HAVE_UNORDERED_MAP if the class we found +# is named unordered_map, or leave it undefined if not. + +# This also checks if unordered map exists. +AC_DEFUN([AC_CXX_STL_HASH], + [ + AC_MSG_CHECKING(the location of hash_map) + AC_LANG_SAVE + AC_LANG_CPLUSPLUS + ac_cv_cxx_hash_map="" + # First try unordered_map, but not on gcc's before 4.2 -- I've + # seen unexplainable unordered_map bugs with -O2 on older gcc's. + AC_TRY_COMPILE([#if defined(__GNUC__) && (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 2)) + # error GCC too old for unordered_map + #endif + ], + [/* no program body necessary */], + [stl_hash_old_gcc=no], + [stl_hash_old_gcc=yes]) + for location in unordered_map tr1/unordered_map; do + for namespace in std std::tr1; do + if test -z "$ac_cv_cxx_hash_map" -a "$stl_hash_old_gcc" != yes; then + # Some older gcc's have a buggy tr1, so test a bit of code. + AC_TRY_COMPILE([#include <$location>], + [const ${namespace}::unordered_map<int, int> t; + return t.find(5) == t.end();], + [ac_cv_cxx_hash_map="<$location>"; + ac_cv_cxx_hash_namespace="$namespace"; + ac_cv_cxx_hash_map_class="unordered_map";]) + fi + done + done + # Now try hash_map + for location in ext/hash_map hash_map; do + for namespace in __gnu_cxx "" std stdext; do + if test -z "$ac_cv_cxx_hash_map"; then + AC_TRY_COMPILE([#include <$location>], + [${namespace}::hash_map<int, int> t], + [ac_cv_cxx_hash_map="<$location>"; + ac_cv_cxx_hash_namespace="$namespace"; + ac_cv_cxx_hash_map_class="hash_map";]) + fi + done + done + ac_cv_cxx_hash_set=`echo "$ac_cv_cxx_hash_map" | sed s/map/set/`; + ac_cv_cxx_hash_set_class=`echo "$ac_cv_cxx_hash_map_class" | sed s/map/set/`; + if test -n "$ac_cv_cxx_hash_map"; then + AC_DEFINE(HAVE_HASH_MAP, 1, [define if the compiler has hash_map]) + AC_DEFINE(HAVE_HASH_SET, 1, [define if the compiler has hash_set]) + AC_DEFINE_UNQUOTED(HASH_MAP_H,$ac_cv_cxx_hash_map, + [the location of <unordered_map> or <hash_map>]) + AC_DEFINE_UNQUOTED(HASH_SET_H,$ac_cv_cxx_hash_set, + [the location of <unordered_set> or <hash_set>]) + AC_DEFINE_UNQUOTED(HASH_NAMESPACE,$ac_cv_cxx_hash_namespace, + [the namespace of hash_map/hash_set]) + AC_DEFINE_UNQUOTED(HASH_MAP_CLASS,$ac_cv_cxx_hash_map_class, + [the name of <hash_map>]) + AC_DEFINE_UNQUOTED(HASH_SET_CLASS,$ac_cv_cxx_hash_set_class, + [the name of <hash_set>]) + AC_MSG_RESULT([$ac_cv_cxx_hash_map]) + else + AC_MSG_RESULT() + AC_MSG_WARN([could not find an STL hash_map]) + fi +]) + |