build-sys: add autoconf macro to pick macro for x32 compatibility

[elogind.git] / m4 / sd_check_max_int_size.m4

diff --git a/m4/sd_check_max_int_size.m4 b/m4/sd_check_max_int_size.m4
new file mode 100644 (file)
index 0000000..a4230b5
--- /dev/null
+++ b/m4/sd_check_max_int_size.m4
@@ -0,0 +1,27 @@
+dnl Find what INT_MAX define to use for a type
+
+#serial 1
+
+ifdef([AC_TR_SH],[], [
+define([AC_TR_SH],
+       [patsubst(translit([[$1]], [*+], [pp]), [[^a-zA-Z0-9_]], [_])])
+define([AC_TR_CPP],
+       [patsubst(translit([[$1]],
+                          [*abcdefghijklmnopqrstuvwxyz],
+                          [PABCDEFGHIJKLMNOPQRSTUVWXYZ]),
+                 [[^A-Z0-9_]], [_])])
+])
+
+AC_DEFUN([SD_CHECK_MAX_INT_SIZE],
+        [AC_CHECK_SIZEOF([long],,)
+         AC_CHECK_SIZEOF([long long],,)
+         AC_CHECK_SIZEOF([$1],,[$2])
+         AS_CASE([$ac_cv_sizeof_[]AC_TR_SH($1)],
+                 [$ac_cv_sizeof_long], [sd_type_max=LONG_MAX],
+                 [$ac_cv_sizeof_long_long], [sd_type_max=LONG_LONG_MAX],
+                 [AC_MSG_ERROR([Don't know how to map $1 to an integer])])
+         AC_DEFINE_UNQUOTED(AC_TR_CPP($1_MAX), [$sd_type_max],
+                   [what int to use to maximize $1])
+         AC_MSG_CHECKING([what int to to use to maximize $1])
+         AC_MSG_RESULT([$sd_type_max])
+])