diff options
author | Aaron Patterson <tenderlove@ruby-lang.org> | 2021-06-30 17:35:04 -0700 |
---|---|---|
committer | Nobuyoshi Nakada <nobu@ruby-lang.org> | 2021-07-13 19:37:46 +0900 |
commit | 5c0d8c6369f92915bf99924f58f0763abe4f493e (patch) | |
tree | 1b26c487b766527a3e5d3c4fcba89ab961952b94 /test | |
parent | a2c9e1b58a9bc1da0533171236da43fcb556ead7 (diff) |
[ruby/fiddle] Add "offsetof" to Struct classes (https://github.com/ruby/fiddle/pull/83)
* Add "offsetof" to Struct classes
I need to get the offset of a member inside a struct without allocating
the struct. This patch adds an "offsetof" class method to structs that
are generated.
The usage is like this:
```ruby
MyStruct = struct [
"int64_t i",
"char c",
]
MyStruct.offsetof("i") # => 0
MyStruct.offsetof("c") # => 8
```
* Update test/fiddle/test_c_struct_builder.rb
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
https://github.com/ruby/fiddle/commit/4e3b60c5b6
Co-authored-by: Sutou Kouhei <kou@cozmixng.org>
Diffstat (limited to 'test')
-rw-r--r-- | test/fiddle/test_c_struct_builder.rb | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/test/fiddle/test_c_struct_builder.rb b/test/fiddle/test_c_struct_builder.rb new file mode 100644 index 0000000000..187424c92d --- /dev/null +++ b/test/fiddle/test_c_struct_builder.rb @@ -0,0 +1,36 @@ +# frozen_string_literal: true +begin + require_relative 'helper' + require 'fiddle/struct' + require 'fiddle/cparser' +rescue LoadError +end + +module Fiddle + class TestCStructBuilder < TestCase + include Fiddle::CParser + + def test_offsetof + types, members = parse_struct_signature(['int64_t i','char c']) + my_struct = Fiddle::CStructBuilder.create(Fiddle::CStruct, types, members) + assert_equal 0, my_struct.offsetof("i") + assert_equal Fiddle::SIZEOF_INT64_T, my_struct.offsetof("c") + end + + def test_offset_with_gap + types, members = parse_struct_signature(['void *p', 'char c', 'long x']) + my_struct = Fiddle::CStructBuilder.create(Fiddle::CStruct, types, members) + + assert_equal PackInfo.align(0, ALIGN_VOIDP), my_struct.offsetof("p") + assert_equal PackInfo.align(SIZEOF_VOIDP, ALIGN_CHAR), my_struct.offsetof("c") + assert_equal SIZEOF_VOIDP + PackInfo.align(SIZEOF_CHAR, ALIGN_LONG), my_struct.offsetof("x") + end + + def test_union_offsetof + types, members = parse_struct_signature(['int64_t i','char c']) + my_struct = Fiddle::CStructBuilder.create(Fiddle::CUnion, types, members) + assert_equal 0, my_struct.offsetof("i") + assert_equal 0, my_struct.offsetof("c") + end + end +end if defined?(Fiddle) |