diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_LONG.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_LONG.h
new file mode 100644
index 0000000..7bf85ee
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_LONG.h
@@ -0,0 +1,16 @@
+// SIZEOF_LONG
+
+#undef SIZEOF_LONG
+
+#ifdef _MSC_VER
+#  define SIZEOF_LONG 4
+#else
+/* Both GCC and Clang (and maybe others) define __SIZEOF_LONG__. */
+#  ifdef __SIZEOF_LONG__
+#    define SIZEOF_LONG __SIZEOF_LONG__
+#  endif
+#endif
+
+#ifndef SIZEOF_LONG
+#  error unable to determine size of long int
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_POINTER.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_POINTER.h
new file mode 100644
index 0000000..b832971
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_POINTER.h
@@ -0,0 +1,23 @@
+// SIZEOF_POINTER
+
+/* See also SIZEOF_SIZE_T (the two may not be the same). */
+
+#undef SIZEOF_POINTER
+
+#ifdef _MSC_VER
+/* _WIN64 is defined for both x64 (x86_64) and ARM64 (aarch64). */
+#  ifdef _WIN64
+#    define SIZEOF_POINTER 8
+#  else
+#    define SIZEOF_POINTER 4
+#  endif
+#else
+/* Both GCC and Clang (and maybe others) define __SIZEOF_POINTER__. */
+#  ifdef __SIZEOF_POINTER__
+#    define SIZEOF_POINTER __SIZEOF_POINTER__
+#  endif
+#endif
+
+#ifndef SIZEOF_POINTER
+#  error unable to determine size of pointer
+#endif
diff --git a/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_SIZE_T.h b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_SIZE_T.h
new file mode 100644
index 0000000..11c1a95
--- /dev/null
+++ b/libbuild2-autoconf/libbuild2/autoconf/checks/SIZEOF_SIZE_T.h
@@ -0,0 +1,23 @@
+// SIZEOF_SIZE_T
+
+/* See also SIZEOF_POINTER (the two may not be the same). */
+
+#undef SIZEOF_SIZE_T
+
+#ifdef _MSC_VER
+/* _WIN64 is defined for both x64 (x86_64) and ARM64 (aarch64). */
+#  ifdef _WIN64
+#    define SIZEOF_SIZE_T 8
+#  else
+#    define SIZEOF_SIZE_T 4
+#  endif
+#else
+/* Both GCC and Clang (and maybe others) define __SIZEOF_SIZE_T__. */
+#  ifdef __SIZEOF_SIZE_T__
+#    define SIZEOF_SIZE_T __SIZEOF_SIZE_T__
+#  endif
+#endif
+
+#ifndef SIZEOF_SIZE_T
+#  error unable to determine size of size_t
+#endif