Reworked FFI generators.

lib/ffi/file_processor.rb

@@ -0,0 +1,87 @@
+require File.expand_path('../generators', __FILE__)
+
+module FFI
+
+  # Processes a file containing Ruby code with blocks of FFI definitions
+  # delimited by @@@. The blocks are replaced with Ruby code produced by
+  # running the FFI generators contained in the blocks. For example:
+  #
+  #   module Something
+  #     @@@
+  #     constants do |c|
+  #       c.include 'somefile.h'
+  #
+  #       c.const 'MAX'
+  #       c.const 'MIN'
+  #     end
+  #     @@@
+  #   end
+  #
+  # would be converted to:
+  #
+  #   module Something
+  #     MAX = 1
+  #     MIN = 2
+  #   end
+  #
+  # assuming that
+  # 
+  #   #define MAX 1
+  #   #define MIN 2
+  #
+  # was contained in the file 'something.h'.
+
+  class FileProcessor
+
+    def initialize(ffi_name, rb_name)
+      @name = File.basename rb_name, '.rb'
+
+      definitions = File.read ffi_name
+
+      replacement = definitions.gsub(/^( *)@@@(.*?)@@@/m) do
+        @constants = []
+        @structs = []
+
+        indent = $1
+        line_count = $2.count("\n") + 1
+
+        instance_eval $2
+
+        lines = []
+        @constants.each { |c| lines << c.to_ruby }
+        @structs.each { |s| lines << s.generate_layout }
+
+        # expand multiline blocks
+        lines = lines.join("\n").split "\n"
+        lines = lines.map { |line| indent + line }
+
+        # preserve source line numbers in output
+        padding = line_count - lines.length
+        lines += [nil] * padding if padding >= 0
+
+        lines.join "\n"
+      end
+
+      File.open rb_name, 'wb' do |f|
+        f.puts "# This file is generated #{self.class} from #{ffi_name}."
+        f.puts
+        f.puts replacement
+      end
+    end
+
+    def constants(options={}, &block)
+      @constants << FFI::ConstGenerator.new(@name, options, &block)
+    end
+
+    def struct(&block)
+      @structs << FFI::StructGenerator.new(@name, &block)
+    end
+
+    ##
+    # Utility converter for constants
+
+    def to_s
+      proc { |obj| obj.to_s.inspect }
+    end
+  end
+end

lib/ffi/generator.rb

@@ -1,58 +1,12 @@
+require File.expand_path('../file_processor', __FILE__)
+
 module FFI
   class Generator
-
     def initialize(ffi_name, rb_name)
-      @ffi_name = ffi_name
-      @rb_name = rb_name
-
-      @name = File.basename rb_name, '.rb'
-
-      file = File.read @ffi_name
-
-      new_file = file.gsub(/^( *)@@@(.*?)@@@/m) do
-        @constants = []
-        @structs = []
-
-        indent = $1
-        original_lines = $2.count "\n"
-
-        instance_eval $2
-
-        new_lines = []
-        @constants.each { |c| new_lines << c.to_ruby }
-        @structs.each { |s| new_lines << s.generate_layout }
-
-        new_lines = new_lines.join("\n").split "\n" # expand multiline blocks
-        new_lines = new_lines.map { |line| indent + line }
-
-        padding = original_lines - new_lines.length
-        new_lines += [nil] * padding if padding >= 0
+      STDERR.puts "FFI::Generator is deprecated. Use FFI::FileProcessor"
+      STDERR.puts "Called from: #{caller(1).first}"
 
-        new_lines.join "\n"
-      end
-
-      open @rb_name, 'w' do |f|
-        f.puts "# This file is generated by rake. Do not edit."
-        f.puts
-        f.puts new_file
-      end
-    end
-
-    def constants(options = {}, &block)
-      @constants << FFI::ConstGenerator.new(@name, options, &block)
-    end
-
-    def struct(&block)
-      @structs << FFI::StructGenerator.new(@name, &block)
+      FileProcessor.new ffi_name, rb_name
     end
-
-    ##
-    # Utility converter for constants
-
-    def to_s
-      proc { |obj| obj.to_s.inspect }
-    end
-
   end
 end
-