--          This file is part of SmartEiffel The GNU Eiffel Compiler.
--       Copyright (C) 1994-2002 LORIA - INRIA - U.H.P. Nancy 1 - FRANCE
--          Dominique COLNET and Suzanne COLLIN - SmartEiffel@loria.fr
--                       http://SmartEiffel.loria.fr
-- SmartEiffel is  free  software;  you can  redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the Free
-- Software  Foundation;  either  version  2, or (at your option)  any  later
-- version. SmartEiffel is distributed in the hope that it will be useful,but
-- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
-- or  FITNESS FOR A PARTICULAR PURPOSE.   See the GNU General Public License
-- for  more  details.  You  should  have  received a copy of the GNU General
-- Public  License  along  with  SmartEiffel;  see the file COPYING.  If not,
-- write to the  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-- Boston, MA 02111-1307, USA.
--
class IMPLICIT_CAST
   --
   -- To memorize an implicit legal cast from one type to another.
   -- This invisible expression is used for all kinds of implicit
   -- conversions:
   --   from INTEGER to REAL
   --   from INTEGER to DOUBLE,
   --   from REAL to DOUBLE,
   --   from INTEGER to reference INTEGER,
   --   from INTEGER_8 to reference INTEGER_8,
   --   ...
   --   from FOO to reference FOO,
   --   ...

inherit EXPRESSION

creation {ASSIGNMENT_HANDLER} make

feature

   is_manifest_string: BOOLEAN is
      do
         Result := expression.is_manifest_string
      end

   to_integer_or_error: INTEGER is
      do
	 to_integer_error
      end

   result_type: E_TYPE is
      do
         Result := destination_type
      end

   is_void: BOOLEAN is
      do
         Result := expression.is_void
      end

   start_lookup_class: BASE_CLASS is
      do
         Result := result_type.base_class
      end

   is_writable: BOOLEAN is
      do
         Result := expression.is_writable
      end

   is_result: BOOLEAN is
      do
         Result := expression.is_result
      end

   is_current: BOOLEAN is
      do
         Result := expression.is_current
      end

   assertion_check(tag: CHARACTER) is
      do
         expression.assertion_check(tag)
      end

   is_static: BOOLEAN is
      do
         Result := expression.is_static
      end

   static_value: INTEGER is
      do
         Result := expression.static_value
      end

   is_pre_computable: BOOLEAN is
      do
         Result := expression.is_pre_computable
      end

   isa_dca_inline_argument: INTEGER is
      do
         Result := expression.isa_dca_inline_argument
      end

   dca_inline_argument(formal_arg_type: E_TYPE) is
      do
         expression.dca_inline_argument(formal_arg_type)
      end

   compile_to_c is
      local
	 i: INTEGER
      do
         c_wrapper_opening
	 if source_type.is_reference then
	    -- To promote automatically reference INTEGER_* type:
	    cpp.put_character('(')
	    from
	       i := 1
	    until
	       conversion.item(i) = 't'
	    loop
	       cpp.put_character(conversion.item(i))
	       i := i + 1
	    end
	    cpp.put_string(fz_70)
	    expression.compile_to_c
	    cpp.put_character(')')
	 else
	    expression.mapping_c_target(source_type)
	 end
         c_wrapper_closing
      end

   mapping_c_target(target_type: E_TYPE) is
      do
	 compile_to_c
      end

   mapping_c_arg(formal_arg_type: E_TYPE) is
      do
	 compile_to_c
      end

   afd_check is
      do
         expression.afd_check
      end

   safety_check is
      do
         expression.safety_check
      end

   collect_c_tmp is
      do
          expression.collect_c_tmp
      end

   c_frame_descriptor(format, locals: STRING) is
      do
	 expression.c_frame_descriptor(format,locals)
      end

   compile_to_jvm is
      local
         space: INTEGER
      do
         expression.compile_to_jvm
         space := source_type.jvm_convert_to(destination_type)
      end

   compile_target_to_jvm is
      local
         space: INTEGER
      do
         expression.compile_target_to_jvm
         space := source_type.jvm_convert_to(destination_type)
      end

   compile_to_jvm_into(dest: E_TYPE): INTEGER is
      do
         compile_to_jvm
         Result := destination_type.jvm_convert_to(dest)
      end

   jvm_branch_if_false: INTEGER is
      do
         Result := expression.jvm_branch_if_false
      end

   jvm_branch_if_true: INTEGER is
      do
         Result := expression.jvm_branch_if_true
      end

   use_current: BOOLEAN is
      do
         Result := expression.use_current
      end

   stupid_switch(run_time_set: RUN_TIME_SET): BOOLEAN is
      do
         Result := expression.stupid_switch(run_time_set)
      end

   c_simple: BOOLEAN is
      do
         Result := expression.c_simple
      end

   can_be_dropped: BOOLEAN is
      do
         Result := expression.can_be_dropped
      end

   to_runnable(ct: E_TYPE): EXPRESSION is
      do
         Result := expression.to_runnable(ct)
      end

   start_position: POSITION is
      do
         Result := expression.start_position
      end

   bracketed_pretty_print, pretty_print is
      do
         expression.pretty_print
      end

   print_as_target is
      do
         expression.print_as_target
      end

   short is
      do
         expression.short
      end

   short_target is
      do
         expression.short_target
      end

   precedence: INTEGER is
      do
         Result := expression.precedence
      end

   jvm_assign_creation, jvm_assign is
      do
         expression.jvm_assign
      end

feature {C_PRETTY_PRINTER}

   original_expression: EXPRESSION is
      do
         Result := expression
      end

feature {NONE}

   expression : EXPRESSION
         -- The wrapped `expression' with it's `source_type'.

   source_type, destination_type: E_TYPE

   conversion: STRING
	 -- If mandatory, the name of the C conversion function (to 
	 -- avoid too many C code generation).
   
   make(e: like expression; dt: like destination_type) is
      require
         e.result_type.run_time_mark /= dt.run_time_mark
	 ; (e.result_type.is_integer and dt.is_integer)
	    or else
	   (e.result_type.is_a(dt))
      do
         expression := e
         source_type := e.result_type.run_type
         destination_type := dt.run_type
	 if source_type.is_expanded and then destination_type.is_expanded
	  then
	    -- May be two INTEGERs of different size or some REAL 
	    -- value converted into DOUBLE for example.
	 else
	    conversion := assignment_handler.register(source_type,
						      destination_type)
	 end
	 if source_type.is_bit and then destination_type.is_reference then
	    smart_eiffel.bit_n_ref_is_nyi_error(e.start_position)
	 end
      ensure
         expression = e
         source_type = e.result_type.run_type
         destination_type = dt.run_type
      end

   c_wrapper_opening is
      do
	 if conversion = Void then
	    cpp.put_string(once "/*IC*/")
	    destination_type.mapping_cast
	 else
	    cpp.put_string(conversion)
	 end
	 cpp.put_character('(')
      end

   c_wrapper_closing is
      do
	 cpp.put_character(')')
      end

end -- IMPLICIT_CAST