[ruby/fiddle] ffi_backend: convert numeric function args to pointers

(https://github.com/ruby/fiddle/pull/162)

This allows for passing integers as pointer arguments to functions when
using the FFI backend. This is a workaround until we can get JRuby's FFI
implementation to allow for it directly (see also
https://github.com/jruby/jruby/pull/8423)

---------

https://github.com/ruby/fiddle/commit/e2f0952e9b

Co-authored-by: Benoit Daloze <eregontp@gmail.com>

2 files changed, 16 insertions, 1 deletions

diff --git a/test/fiddle/test_function.rb b/test/fiddle/test_function.rb
index 146dcc7205..b408a14ccd 100644
--- a/test/fiddle/test_function.rb
+++ b/test/fiddle/test_function.rb
@@ -98,6 +98,15 @@ module Fiddle
       assert_in_delta 1.0, func.call(90 * Math::PI / 180), 0.0001
     end
 
+    def test_integer_pointer_conversion
+      func = Function.new(@libc['memcpy'], [TYPE_VOIDP, TYPE_VOIDP, TYPE_SIZE_T], TYPE_VOIDP)
+      str = 'hello'
+      Pointer.malloc(str.bytesize, Fiddle::RUBY_FREE) do |dst|
+        func.call(dst.to_i, str, dst.size)
+        assert_equal(str, dst.to_str)
+      end
+    end
+
     def test_argument_count
       closure_class = Class.new(Closure) do
         def call one
diff --git a/test/fiddle/test_pointer.rb b/test/fiddle/test_pointer.rb
index 673e7ca445..9d490f9f26 100644
--- a/test/fiddle/test_pointer.rb
+++ b/test/fiddle/test_pointer.rb
@@ -157,11 +157,17 @@ module Fiddle
       end
     end
 
-    def test_to_ptr_with_num
+    def test_to_ptr_with_int
       ptr = Pointer.new 0
       assert_equal ptr, Pointer[0]
     end
 
+    MimicInteger = Struct.new(:to_int)
+    def test_to_ptr_with_to_int
+      ptr = Pointer.new 0
+      assert_equal ptr, Pointer[MimicInteger.new(0)]
+    end
+
     def test_equals
       ptr   = Pointer.new 0
       ptr2  = Pointer.new 0