+AC_CACHE_CHECK(
+ [for constexpr strlen],
+ [folly_cv_func_constexpr_strlen],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <cstring>
+ static constexpr int val = strlen("foo");]],
+ [folly_cv_func_constexpr_strlen=yes],
+ [folly_cv_func_constexpr_strlen=no])])
+
+if test "$folly_cv_func_constexpr_strlen" = yes; then
+ AC_DEFINE([HAVE_CONSTEXPR_STRLEN], [1],
+ [Define to 1 if strlen(3) is constexpr.])
+fi
+
+AC_CACHE_CHECK(
+ [for libc++],
+ [folly_cv_lib_libcpp],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <type_traits>
+ #if !_LIBCPP_VERSION
+ #error No libc++
+ #endif
+ void func() {}]
+ ],
+ [folly_cv_lib_libcpp=yes],
+ [folly_cv_lib_libcpp=no])])
+
+if test "$folly_cv_lib_libcpp" = yes; then
+ AC_DEFINE([USE_LIBCPP], [1], [Define to 1 if we're using libc++.])
+fi
+
+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
+
+# Figure out if we support weak symbols. If not, we will link in some null
+# stubs for functions that would otherwise be weak.
+AC_CACHE_CHECK(
+ [for weak symbol support],
+ [folly_cv_prog_cc_weak_symbols],
+ [AC_LINK_IFELSE(
+ [AC_LANG_SOURCE[
+ extern "C" void configure_link_extern_weak_test() __attribute__((weak));
+ int main(int argc, char** argv) {
+ return configure_link_extern_weak_test == nullptr;
+ }]],
+ [folly_cv_prog_cc_weak_symbols="yes"],
+ [folly_cv_prog_cc_weak_symbols="no"])])
+
+if test "$folly_cv_prog_cc_weak_symbols" = yes; then
+ AC_DEFINE([HAVE_WEAK_SYMBOLS], [1],
+ [Define to 1 if the linker supports weak symbols.])
+fi
+
+AC_CACHE_CHECK(
+ [for vsnprintf reporting bad format strings],
+ [folly_cv_prog_vsnprintf_bad_format],
+ [AC_RUN_IFELSE(
+ [AC_LANG_SOURCE[
+ #include <stdio.h>
+
+ int main(int argc, char** argv) {
+ char buf[256];
+ return vsnprintf(buf, sizeof(buf), "%", 1) < 0 ? 0 : 1;
+ }]],
+ [folly_cv_prog_vsnprintf_bad_format="yes"],
+ [folly_cv_prog_vsnprintf_bad_format="no"])])
+
+if test "$folly_cv_prog_vsnprintf_bad_format" = yes; then
+ AC_DEFINE([HAVE_VSNPRINTF_ERRORS], [1],
+ [Define to 1 if the vsnprintf supports returning errors on bad format strings.])
+fi
+
+AC_SEARCH_LIBS([cplus_demangle_v3_callback], [iberty_pic iberty])
+if test "$ac_cv_search_cplus_demangle_v3_callback" != "no" ; then
+ AC_DEFINE([HAVE_CPLUS_DEMANGLE_V3_CALLBACK], [1],
+ [Define to 1 if we have cplus_demangle_v3_callback.])
+fi