+AC_CACHE_CHECK(
+ [for ifunc support],
+ [folly_cv_prog_cc_ifunc],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #pragma GCC diagnostic error "-Wattributes"
+ extern "C" void (*test_ifunc(void))() { return 0; }
+ void func() __attribute__((ifunc("test_ifunc")));]
+ ],
+ [folly_cv_prog_cc_ifunc=yes],
+ [folly_cv_prog_cc_ifunc=no])])
+
+if test "$folly_cv_prog_cc_ifunc" = "yes"; then
+ AC_DEFINE([HAVE_IFUNC], [1], [Define to 1 if the compiler supports ifunc])
+fi
+
+AC_CACHE_CHECK(
+ [for final and override support],
+ [folly_cv_c_final_override],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[class C { virtual void f() final {} virtual void g() {} };
+ class D : public C { virtual void g() override {} };]],
+ [folly_cv_c_final_override=yes],
+ [folly_cv_c_final_override=no])])
+
+if test "$folly_cv_c_final_override" = "yes"; then
+ final_val=final
+ override_val=override
+else
+ final_val=
+ override_val=
+fi
+
+AC_DEFINE_UNQUOTED(
+ [FINAL], [$final_val],
+ [Define to "final" if the compiler supports C++11 "final"])
+AC_DEFINE_UNQUOTED(
+ [OVERRIDE], [$override_val],
+ [Define to "override" if the compiler supports C++11 "override"])
+
+AC_CACHE_CHECK(
+ [for libc++],
+ [folly_cv_lib_libcpp],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <type_traits>
+ #if !_LIBCPP_VERSION
+ #error No libc++
+ #endif
+ void func() {}]
+ ],
+ [folly_cv_lib_libcpp=yes],
+ [folly_cv_lib_libcpp=no])])
+
+if test "$folly_cv_lib_libcpp" = yes; then
+ AC_DEFINE([USE_LIBCPP], [1], [Define to 1 if we are using libc++.])
+fi
+
+AC_CACHE_CHECK(
+ [for c++11 atomic support without GNU Atomic library],
+ [folly_cv_lib_libatomic],
+ [AC_LINK_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <atomic>
+ int main() {
+ struct Test { int val; };
+ std::atomic<Test> s;
+ s.is_lock_free();
+ }
+ ]],
+ [folly_cv_lib_libatomic=yes],
+ [folly_cv_lib_libatomic=no])])
+
+if test "$folly_cv_lib_libatomic" = no; then
+ AC_HAVE_LIBRARY([atomic],[],[AC_MSG_ERROR(
+ [Please install the GNU Atomic library])])
+fi
+
+if test "$build_os" = "linux-gnu"; then
+ AC_HAVE_LIBRARY([dl],[],[AC_MSG_ERROR(
+ [Folly depends on libdl])])
+fi
+
+AC_CACHE_CHECK(
+ [for liblinux-vdso support],
+ [folly_cv_lib_liblinux_vdso],
+ [AC_RUN_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <dlfcn.h>
+ int main() {
+ void *h = dlopen("linux-vdso.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+ if (h == nullptr) {
+ return -1;
+ }
+ dlclose(h);
+ return 0;
+ }
+ ]],
+ [folly_cv_lib_liblinux_vdso=yes],
+ [folly_cv_lib_liblinux_vdso=no])])
+
+if test "$folly_cv_lib_liblinux_vdso" = yes; then
+ AC_DEFINE([HAVE_LINUX_VDSO], [1], [Define to 1 if liblinux-vdso is available])
+fi
+
+AC_DEFINE([HAVE_PTHREAD], [1], [Define to 1 if pthread is avaliable])
+
+AC_CACHE_CHECK(
+ [for usable std::is_trivially_copyable],
+ [folly_cv_decl_std_is_trivially_copyable],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <type_traits>
+ const bool val = std::is_trivially_copyable<bool>::value;]
+ ],
+ [folly_cv_decl_std_is_trivially_copyable=yes],
+ [folly_cv_decl_std_is_trivially_copyable=no])])
+
+if test "$folly_cv_decl_std_is_trivially_copyable" = yes; then
+ AC_DEFINE([HAVE_STD__IS_TRIVIALLY_COPYABLE], [1],
+ [Define to 1 if we have a usable std::is_trivially_copyable<T>
+ implementation.])
+fi
+
+AC_CACHE_CHECK(
+ [gflags namespace],
+ [folly_cv_decl_gflags_namespace],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <gflags/gflags.h>
+ void foo() { gflags::GetArgv(); }]
+ ],
+ [folly_cv_decl_gflags_namespace=gflags],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <gflags/gflags.h>
+ void foo() { google::GetArgv(); }]
+ ],
+ [folly_cv_decl_gflags_namespace=google],
+ [folly_cv_decl_gflags_namespace=error])])])
+
+if test "$folly_cv_decl_gflags_namespace" = error; then
+ AC_MSG_ERROR([Cannot determine gflags namespace])
+else
+ AC_DEFINE_UNQUOTED(
+ [GFLAGS_NAMESPACE], [$folly_cv_decl_gflags_namespace],
+ [Define to gflags namespace (usually "google" or "gflags")])
+ if test "$folly_cv_decl_gflags_namespace" != gflags; then
+ AC_DEFINE([UNUSUAL_GFLAGS_NAMESPACE], [1],
+ [Define to 1 if the gflags namespace is not "gflags"])
+ fi
+fi