Added accessors for members Data_Wrap_Structs

[git-p4: depot-paths = "//src/RubyInline/dev/": change = 4354]

History.txt

@@ -5,6 +5,7 @@
   * Inline::C now uses ZenTestMapping to automatically map C functions to ruby
     names.
   * Inline::C#map_c_const can now map to a ruby constant name.
+  * Added accessors for members of Data_Wrap_Structs.  See Inline::C#accessor.
 
 === 3.7.0 / 2008-06-09
 

lib/inline.rb

@@ -114,6 +114,7 @@ def self.directory
     @@directory
   end
 
+  ##
   # Inline::C is the default builder used and the only one provided by
   # Inline. It can be used as a template to write builders for other
   # languages. It understands type-conversions for the basic types and
@@ -123,8 +124,6 @@ class C
 
     include ZenTestMapping
 
-    protected unless $TESTING
-
     MAGIC_ARITY_THRESHOLD = 15
     MAGIC_ARITY = -1
 
@@ -275,12 +274,14 @@ def so_name
     end
 
     attr_reader :rb_file, :mod
-    if $TESTING then
-      attr_writer :mod
-      attr_accessor :src, :sig, :flags, :libs, :init_extra
-    end
+    attr_writer :mod
+    attr_accessor :src, :sig, :flags, :libs, :init_extra
 
-    public
+    ##
+    # Sets the name of the C struct for generating accessors.  Used with
+    # #accessor, #reader, #writer.
+
+    attr_accessor :struct_name
 
     def initialize(mod)
       raise ArgumentError, "Class/Module arg is required" unless Module === mod
@@ -305,6 +306,67 @@ def initialize(mod)
       @inherited_methods = {}
     end
 
+    ##
+    # Adds a #reader and #writer for a C struct member wrapped via
+    # Data_Wrap_Struct.  +method+ is the ruby name to give the accessor,
+    # +type+ is the C type.  Unless the C member name is overridden with
+    # +member+, the method name is used as the struct member.
+    #
+    #   builder.struct_name = 'MyStruct'
+    #   builder.accessor :title,        'char *'
+    #   builder.accessor :stream_index, 'int',   :index
+    #
+    # The latter accesses MyStruct->index via the stream_index method.
+
+    def accessor(method, type, member = method)
+      reader method, type, member
+      writer method, type, member
+    end
+
+    ##
+    # Adds a reader for a C struct member wrapped via Data_Wrap_Struct.
+    # +method+ is the ruby name to give the reader, +type+ is the C type.
+    # Unless the C member name is overridden with +member+, the method
+    # name is used as the struct member.  See #accessor for an example.
+
+    def reader(method, type, member = method)
+      raise "struct name not set for reader #{method} #{type}" unless
+        @struct_name
+
+      c <<-C
+VALUE #{method}() {
+  #{@struct_name} *pointer;
+
+  Data_Get_Struct(self, #{@struct_name}, pointer);
+
+  return #{c2ruby type}(pointer->#{member});
+}
+      C
+    end
+
+    ##
+    # Adds a writer for a C struct member wrapped via Data_Get_Struct.
+    # +method+ is the ruby name to give the writer, +type+ is the C type.
+    # Unless the C member name is overridden with +member+, the method
+    # name is used as the struct member.  See #accessor for an example.
+
+    def writer(method, type, member = method)
+      raise "struct name not set for writer #{method} #{type}" unless
+        @struct_name
+
+      c <<-C
+VALUE #{method}_equals(VALUE value) {
+  #{@struct_name} *pointer;
+
+  Data_Get_Struct(self, #{@struct_name}, pointer);
+
+  pointer->#{member} = #{ruby2c type}(value);
+
+  return value;
+}
+      C
+    end
+
     ##
     # Converts ruby type +type+ to a C type
 

test/test_inline.rb

@@ -101,6 +101,216 @@ def test_initialize
     assert_equal [], x.libs
   end
 
+  def test_accessor
+    builder = Inline::C.new self.class
+
+    builder.struct_name = 'MyStruct'
+    builder.accessor 'method_name', 'int'
+
+    source = util_strip_lines builder.src
+
+    expected = []
+    expected << <<-READER
+# line N "./lib/inline.rb"
+static VALUE method_name(VALUE self) {
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  return (INT2FIX(pointer->method_name));
+}
+    READER
+
+    expected << <<-WRITER
+# line N "./lib/inline.rb"
+static VALUE method_name_equals(VALUE self, VALUE _value) {
+  VALUE value = (_value);
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  pointer->method_name = FIX2INT(value);
+
+  return (value);
+}
+    WRITER
+
+    assert_equal expected, source
+  end
+
+  def test_accessor_member_name
+    builder = Inline::C.new self.class
+
+    builder.struct_name = 'MyStruct'
+    builder.accessor 'method_name', 'int', 'member_name'
+
+    source = util_strip_lines builder.src
+
+    expected = []
+    expected << <<-READER
+# line N "./lib/inline.rb"
+static VALUE method_name(VALUE self) {
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  return (INT2FIX(pointer->member_name));
+}
+    READER
+
+    expected << <<-WRITER
+# line N "./lib/inline.rb"
+static VALUE method_name_equals(VALUE self, VALUE _value) {
+  VALUE value = (_value);
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  pointer->member_name = FIX2INT(value);
+
+  return (value);
+}
+    WRITER
+
+    assert_equal expected, source
+  end
+
+  def test_accessor_no_struct_name
+    builder = Inline::C.new self.class
+
+    e = assert_raises RuntimeError do
+      builder.accessor 'method_name', 'int'
+    end
+
+    assert_equal "struct name not set for reader method_name int", e.message
+  end
+
+  def test_reader
+    builder = Inline::C.new self.class
+
+    builder.struct_name = 'MyStruct'
+    builder.reader 'method_name', 'int'
+
+    source = util_strip_lines builder.src
+
+    expected = []
+    expected << <<-READER
+# line N "./lib/inline.rb"
+static VALUE method_name(VALUE self) {
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  return (INT2FIX(pointer->method_name));
+}
+    READER
+
+    assert_equal expected, source
+  end
+
+  def test_reader_member_name
+    builder = Inline::C.new self.class
+
+    builder.struct_name = 'MyStruct'
+    builder.reader 'method_name', 'int', 'member_name'
+
+    source = util_strip_lines builder.src
+
+    expected = []
+    expected << <<-READER
+# line N "./lib/inline.rb"
+static VALUE method_name(VALUE self) {
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  return (INT2FIX(pointer->member_name));
+}
+    READER
+
+    assert_equal expected, source
+  end
+
+  def test_reader_no_struct_name
+    builder = Inline::C.new self.class
+
+    e = assert_raises RuntimeError do
+      builder.reader 'method_name', 'int'
+    end
+
+    assert_equal "struct name not set for reader method_name int", e.message
+  end
+
+  def test_writer
+    builder = Inline::C.new self.class
+
+    builder.struct_name = 'MyStruct'
+    builder.writer 'method_name', 'int'
+
+    source = util_strip_lines builder.src
+
+    expected = []
+    expected << <<-WRITER
+# line N "./lib/inline.rb"
+static VALUE method_name_equals(VALUE self, VALUE _value) {
+  VALUE value = (_value);
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  pointer->method_name = FIX2INT(value);
+
+  return (value);
+}
+    WRITER
+
+    assert_equal expected, source
+  end
+
+  def test_writer_member_name
+    builder = Inline::C.new self.class
+
+    builder.struct_name = 'MyStruct'
+    builder.writer 'method_name', 'int', 'member_name'
+
+    source = util_strip_lines builder.src
+
+    expected = []
+    expected << <<-WRITER
+# line N "./lib/inline.rb"
+static VALUE method_name_equals(VALUE self, VALUE _value) {
+  VALUE value = (_value);
+
+  MyStruct *pointer;
+
+  Data_Get_Struct(self, MyStruct, pointer);
+
+  pointer->member_name = FIX2INT(value);
+
+  return (value);
+}
+    WRITER
+
+    assert_equal expected, source
+  end
+
+  def test_writer_no_struct_name
+    builder = Inline::C.new self.class
+
+    e = assert_raises RuntimeError do
+      builder.writer 'method_name', 'int'
+    end
+
+    assert_equal "struct name not set for writer method_name int", e.message
+  end
+
   def test_ruby2c
     x = Inline::C.new(self.class)
     assert_equal 'NUM2CHR',        x.ruby2c("char")
@@ -249,6 +459,7 @@ def test_parse_signature_register
 
   def util_generate(src, expected, expand_types=true)
     result = @builder.generate src, expand_types
+    result = util_strip_lines result
     result.gsub!(/\# line \d+/, '# line N')
     expected = "# line N \"#{$0}\"\n" + expected
     assert_equal(expected, result)
@@ -258,6 +469,17 @@ def util_generate_raw(src, expected)
     util_generate(src, expected, false)
   end
 
+  def util_strip_lines(src)
+    case src
+    when String then
+      src.gsub(/\# line \d+/, '# line N')
+    when Array then
+      src.map do |chunk|
+        util_strip_lines chunk
+      end
+    end
+  end
+
   # Ruby Arity Rules, from the mouth of Matz:
   # -2 = ruby array argv
   # -1 = c array argv