1 files changed, 14 insertions, 0 deletions
diff --git a/ext/fiddle/extconf.rb b/ext/fiddle/extconf.rb
index 03b0ac2765..95589028d0 100644
--- a/ext/fiddle/extconf.rb
+++ b/ext/fiddle/extconf.rb
@@ -19,6 +19,20 @@ end
 
 have_header 'sys/mman.h'
 
+config = File.read(RbConfig.expand(File.join($arch_hdrdir, "ruby/config.h")))
+types = {"SIZE_T"=>"SSIZE_T", "PTRDIFF_T"=>nil, "INTPTR_T"=>nil}
+types.each do |type, signed|
+  if /^\#define\s+SIZEOF_#{type}\s+(SIZEOF_(.+)|\d+)/ =~ config
+    if size = $2 and size != 'VOIDP'
+      size = types.fetch(size) {size}
+      $defs << format("-DTYPE_%s=TYPE_%s", signed||type, size)
+    end
+    if signed
+      check_signedness(type.downcase, "stddef.h")
+    end
+  end
+end
+
 create_makefile 'fiddle'
 
 # :startdoc: