protobuf/m4/stl_hash.m4
2010-12-07 06:23:55 +00:00

73 lines
3.3 KiB
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# 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
])