+# Make sure the C compiler supports C99
+AS_IF([test "$ac_cv_prog_cc_c99" = "no"], [AC_MSG_ERROR([The compiler does not support C99])])
+
+# Enable available system extensions and LFS support
+AC_USE_SYSTEM_EXTENSIONS
+AC_SYS_LARGEFILE
+
+## ##
+## C++ compiler checks ##
+## ##
+
+# Require a C++11 compiler without GNU extensions (-std=c++11)
+AX_CXX_COMPILE_STDCXX([11], [noext], [mandatory])
+
+# Make sure the C compiler supports __attribute__
+AX_C___ATTRIBUTE__
+AS_IF([test "x$ax_cv___attribute__" != "xyes"],
+ [AC_MSG_ERROR([The compiler does not support __attribute__ extensions])])
+
+# Make sure we have pthread support
+AX_PTHREAD([], [AC_MSG_ERROR([Could not configure pthread support])])
+
+# Checks for typedefs, structures, and compiler characteristics.
+AC_C_INLINE
+AC_C_TYPEOF
+AC_TYPE_INT32_T
+AC_TYPE_PID_T
+AC_TYPE_SIZE_T
+AC_TYPE_SSIZE_T
+AC_TYPE_UINT16_T
+AC_TYPE_UINT32_T
+AC_TYPE_UINT64_T
+AC_TYPE_UINT8_T
+
+# Detect warning flags supported by the C compiler and append them to
+# WARN_CFLAGS.
+m4_define([WARN_FLAGS_LIST], [ dnl
+ -Wall dnl
+ -Wextra dnl
+ -Wmissing-prototypes dnl
+ -Wmissing-declarations dnl
+ -Wnull-dereference dnl
+ -Wundef dnl
+ -Wshadow dnl
+ -Wjump-misses-init dnl
+ -Wsuggest-attribute=format dnl
+ -Wtautological-constant-out-of-range-compare dnl
+ -Wnested-externs dnl
+ -Wwrite-strings dnl
+ -Wformat=2 dnl
+ -Wstrict-aliasing dnl
+ -Wmissing-noreturn dnl
+ -Winit-self dnl
+ -Wduplicated-cond dnl
+ -Wduplicated-branches dnl
+ -Wlogical-op dnl
+ dnl
+ dnl-Wredundant-decls dnl
+ -Wno-null-dereference dnl
+])
+
+# Pass -Werror as an extra flag during the test: this is needed to make the
+# -Wunknown-warning-option diagnostic fatal with clang.
+AC_LANG_PUSH([C])
+AX_APPEND_COMPILE_FLAGS([WARN_FLAGS_LIST], [WARN_CFLAGS], [-Werror])
+AC_LANG_POP([C])
+
+AC_LANG_PUSH([C++])
+AX_APPEND_COMPILE_FLAGS([WARN_FLAGS_LIST], [WARN_CXXFLAGS], [-Werror])
+AC_LANG_POP([C++])
+
+AE_IF_FEATURE_ENABLED([Werror], [WARN_CFLAGS="${WARN_CFLAGS} -Werror"])
+AE_IF_FEATURE_ENABLED([Werror], [WARN_CXXFLAGS="${WARN_CXXFLAGS} -Werror"])
+
+
+## ##
+## Header checks ##
+## ##
+
+AC_HEADER_STDBOOL
+AC_CHECK_HEADERS([ \
+ limits.h \
+ stddef.h \
+ sys/param.h \
+ sys/time.h \
+])
+
+
+## ##
+## Programs checks ##
+## ##
+