--          This file is part of SmallEiffel The GNU Eiffel Compiler.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - colnet@loria.fr 
--                       http://www.loria.fr/SmallEiffel
-- SmallEiffel 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. SmallEiffel 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  SmallEiffel;  see the file COPYING.  If not,
-- write to the  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-- Boston, MA 02111-1307, USA.
--
class CONSTANT_POOL
   -- 
   -- Unique Global Object in charge of the CONSTANT_POOL 
   -- handling (the CONSTANT_POOL is an important part of a 
   -- JVM *.class file).
   --

inherit CP_INFO_TAGS;

feature {NONE}

   cp_up: INTEGER;
   
   cp: FIXED_ARRAY[CP_INFO] is
	 -- Range [1.. `cp_up'] has no Void elements.
	 -- By the way, index 0 is not used and elements
	 -- are recycled.
      once
	 !!Result.make(1);
      end;

feature {NONE}

   fz_java_lang_object       : STRING is "java/lang/Object";

feature {PRINT_JVM_CLASS}

   reset(new_upper: INTEGER) is
      require
	 new_upper > 0
      local
	 cp_info: CP_INFO;
	 i: INTEGER;
      do
	 from
	    cp_up := 0;
	 until
	    i = new_upper
	 loop
	    add_last.clear;
	    i := i + 1;
	 end;
      ensure
	 cp_up = new_upper
      end;

feature {JVM}

   clear is
      local
	 idx: INTEGER;
      do
	 cp_up := 0;
	 -- Compute minimum standard idx :
	 idx_java_lang_object := idx_class2(fz_java_lang_object);
	 idx_jvm_root_class := idx_class2(jvm_root_class);
	 idx_uft8_code := idx_uft8("Code");
      end;

   write_bytes is
      local
	 i: INTEGER;
      do
	 echo.put_string("Constant pool: ");
	 echo.put_integer(cp_up);
	 echo.put_new_line;
	 jvm.b_put_u2(cp_up + 1);
	 from
	    i := 1;
	 until
	    i > cp_up
	 loop
	    cp.item(i).b_put;
	    i := i + 1;
	 end;
      end;

feature -- Acces to some common idx :

   idx_uft8_code: INTEGER;

   idx_java_lang_object: INTEGER;

   idx_jvm_root_class: INTEGER;

feature 

   valid_index(idx: INTEGER): BOOLEAN is
      do
	 Result := (1 <= idx) and then (idx <= cp_up);
      end;

feature {PRINT_JVM_CLASS} -- Setting :

   set_class(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_class(info);
      end;

   set_fieldref(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_fieldref(info);
      end;

   set_methodref(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_methodref(info);
      end;

   set_interface_methodref(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_interface_methodref(info);
      end;

   set_string(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_string(info);
      end;

   set_integer(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_integer(info);
      end;

   set_float(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_float(info);
      end;

   set_long(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_long(info);
      end;

   set_double(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_double(info);
      end;

   set_name_and_type(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_name_and_type(info);
      end;

   set_uft8(i: INTEGER; info: STRING) is
      do
	 cp.item(i).set_uft8(info);
      end;

feature -- Testing :

   is_class(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_class;
      end;

   is_fieldref(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_fieldref;
      end;

   is_methodref(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_methodref;
      end;

   is_interface_methodref(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_interface_methodref;
      end;

   is_string(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_string;
      end;

   is_integer(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_integer;
      end;

   is_float(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_float;
      end;

   is_long(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_long;
      end;

   is_double(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_double;
      end;

   is_name_and_type(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_name_and_type;
      end;

   is_uft8(idx: INTEGER): BOOLEAN is
      do
	 Result := cp.item(idx).is_uft8;
      end;

feature -- Update and search :
   
   idx_class2(name: STRING): INTEGER is
	 -- Where `name' can be fully qualified or unqualified.
      local
	 uft8: INTEGER;
      do
	 uft8 := idx_uft8(name);
	 from
	    Result := cp_up;
	 until
	    Result = 0 or else cp.item(Result).is_class_idx(uft8)
	 loop
	    Result := Result - 1;
	 end;
	 if Result = 0 then
	    tmp_info.clear;
	    tmp_info_append_u2(uft8);
	    add_last.set_class(tmp_info);
	    Result := cp_up;
	 end;
      end;

   idx_fieldref_for_manifest_string(key: STRING): INTEGER is
      require
	 key /= Void
      local
	 c, nt: INTEGER;
      do
	 c := idx_class2(jvm_root_class);
	 nt := idx_name_and_type2(key,jvm_string_descriptor);
	 Result := idx_fieldref2(c,nt);
      ensure
	 valid_index(Result)
      end;

   idx_fieldref(rf: RUN_FEATURE): INTEGER is
      require
	 rf /= Void
      local
	 c, nt: INTEGER;
      do
	 c := rf.run_class.fully_qualified_constant_pool_index;
	 nt := idx_name_and_type(rf);
	 Result := idx_fieldref2(c,nt);
      ensure
	 valid_index(Result)
      end;

   idx_fieldref2(c, nt: INTEGER): INTEGER is
      require
	 valid_index(c);
	 valid_index(nt)
      do
	 from
	    Result := cp_up;
	 until
	    Result = 0 or else cp.item(Result).is_fieldref_idx(c,nt)
	 loop
	    Result := Result - 1;
	 end;
	 if Result = 0 then
	    tmp_info.clear;
	    tmp_info_append_u2(c);
	    tmp_info_append_u2(nt);
	    add_last.set_fieldref(tmp_info);
	    Result := cp_up;
	 end;
      ensure
	 valid_index(Result)
      end;

   idx_fieldref3(class_name, field_name, descriptor: STRING): INTEGER is
	 -- Where `class_name' is the fully qualified name.
      require
	 not class_name.empty;
	 not field_name.empty;
	 not descriptor.empty
      local
	 c: INTEGER;
      do
	 c := idx_class2(class_name);
	 Result := idx_fieldref4(c,field_name,descriptor);
      end;

   idx_fieldref4(c: INTEGER; field_name, descriptor: STRING): INTEGER is
      local
	 nt: INTEGER;
      do
	 nt := idx_name_and_type2(field_name,descriptor);
	 Result := idx_fieldref2(c,nt);
      end;

   idx_fieldref5(c, n, t: INTEGER): INTEGER is
      local
	 nt: INTEGER;
      do
	 nt := idx_name_and_type3(n,t);
	 Result := idx_fieldref2(c,nt);
      end;

   idx_methodref(rf: RUN_FEATURE): INTEGER is
      require
	 rf /= Void
      local
	 c, nt: INTEGER;
      do
	 c := rf.run_class.fully_qualified_constant_pool_index;
	 nt := idx_name_and_type(rf);
	 Result := idx_methodref2(c,nt);
      ensure
	 valid_index(Result)
      end;

   idx_methodref1(c: INTEGER; method_name, descriptor: STRING): INTEGER is
      require
	 valid_index(c);
	 not method_name.empty;
	 not descriptor.empty
      local
	 nt: INTEGER;
      do
	 nt := idx_name_and_type2(method_name,descriptor);
	 Result := idx_methodref2(c,nt);
      end;

   idx_methodref2(c, nt: INTEGER): INTEGER is
      require
	 valid_index(c);
	 valid_index(nt)
      do
	 from
	    Result := cp_up;
	 until
	    Result = 0 or else cp.item(Result).is_methodref_idx(c,nt)
	 loop
	    Result := Result - 1;
	 end;
	 if Result = 0 then
	    tmp_info.clear;
	    tmp_info_append_u2(c);
	    tmp_info_append_u2(nt);
	    add_last.set_methodref(tmp_info);
	    Result := cp_up;
	 end;
      ensure
	 valid_index(Result)
      end;

   idx_methodref3(class_name, method_name, descriptor: STRING): INTEGER is
	 -- Where `class_name' is the fully qualified name.
      require
	 not class_name.empty;
	 not method_name.empty;
	 not descriptor.empty
      local
	 c: INTEGER;
      do
	 c := idx_class2(class_name);
	 Result := idx_methodref1(c,method_name,descriptor);
      end;

   idx_string(str: STRING): INTEGER is
	 -- Assume `str' has no '%/0/' and no ['%/128/'..'%/255/']
      local
	 uft8: INTEGER;
      do
	 uft8 := idx_uft8(str);
	 from
	    Result := cp_up;
	 until
	    Result = 0 or else cp.item(Result).is_string_idx(uft8)
	 loop
	    Result := Result - 1;
	 end;
	 if Result = 0 then
	    tmp_info.clear;
	    tmp_info_append_u2(uft8);
	    add_last.set_string(tmp_info);
	    Result := cp_up;
	 end;
      end;

   idx_string2(str: STRING): INTEGER is
	 -- For all kinds of STRINGs (see idx_string)
      local
	 i: INTEGER;
	 c: CHARACTER;
      do
	 from
	    tmp_uft8.clear;
	    i := 1;
	 until
	    i > str.count
	 loop
	    c := str.item(i);
	    inspect
	       c.to_integer
	    when 0 then
	       tmp_uft8.extend((192).to_character);
	       tmp_uft8.extend((128).to_character);
	    when 1 .. 127 then
	       tmp_uft8.extend(c);
	    when 128 .. 191 then
	       tmp_uft8.extend((194).to_character);
	       tmp_uft8.extend(c);
	    when 192 .. 255 then
	       tmp_uft8.extend((195).to_character);
	       tmp_uft8.extend((c.to_integer - 64).to_character);
	    end;
	    i := i + 1;
	 end;
	 Result := idx_string(tmp_uft8);
      end;

   idx_name_and_type2(name, descriptor: STRING): INTEGER is
      local
	 d: INTEGER;
      do
	 d := idx_uft8(descriptor);
	 Result := idx_name_and_type1(name,d);
      ensure
	 valid_index(Result)
      end;

   idx_name_and_type3(n, d: INTEGER): INTEGER is
      do
	 from
	    Result := cp_up;
	 until
	    Result = 0 or else cp.item(Result).is_name_and_type_idx(n,d)
	 loop
	    Result := Result - 1;
	 end;
	 if Result = 0 then
	    tmp_info.clear;
	    tmp_info_append_u2(n);
	    tmp_info_append_u2(d);
	    add_last.set_name_and_type(tmp_info);
	    Result := cp_up;
	 end;
      ensure
	 valid_index(Result)
      end;

   idx_name_and_type1(name: STRING; d: INTEGER): INTEGER is
      local
	 n: INTEGER;
      do
	 n := idx_uft8(name);
	 Result := idx_name_and_type3(n,d);
      ensure
	 valid_index(Result)
      end;

   idx_name_and_type(rf: RUN_FEATURE): INTEGER is
      do
	 Result := idx_name_and_type2(rf.name.to_key,rf.jvm_descriptor);
      ensure
	 valid_index(Result)
      end;

   idx_uft8(contents: STRING): INTEGER is
      do
	 from
	    Result := cp_up;
	 until
	    Result = 0 or else cp.item(Result).is_uft8_idx(contents)
	 loop
	    Result := Result - 1;
	 end;
	 if Result = 0 then
	    string_to_uft8(contents,tmp_info);
	    add_last.set_uft8(tmp_info);
	    Result := cp_up;
	 end;
      ensure
	 valid_index(Result)
      end;

feature

   idx_fieldref_generating_type(c: INTEGER): INTEGER is
      local
	 idx, nt: INTEGER;
      do
	 idx := idx_eiffel_string_descriptor;
	 nt := idx_name_and_type1(us_generating_type,idx);
	 Result := idx_fieldref2(c,nt);
      end;

   idx_fieldref_generator(c: INTEGER): INTEGER is
      local
	 idx, nt: INTEGER;
      do
	 idx := idx_eiffel_string_descriptor;
	 nt := idx_name_and_type1(us_generator,idx);
	 Result := idx_fieldref2(c,nt);
      end;
   
feature {PRINT_JVM_CLASS,CP_INFO}

   view_in(str: STRING; idx: INTEGER) is
	 -- Append in `str' a human readable version.
      require
	 valid_index(idx);
	 str /= Void
      do
	 cp.item(idx).view_in(str);
      end;

feature {CODE_ATTRIBUTE}

   idx_eiffel_string_class: INTEGER is
      do
	 Result := idx_class2(jvm_string_class);
      end;

   idx_eiffel_string_count_fieldref: INTEGER is
      local
	 idx: INTEGER;
      do
	 idx := idx_name_and_type2(us_count,fz_30);
	 Result := idx_fieldref2(idx_eiffel_string_class,idx);
      end;

   idx_eiffel_string_capacity_fieldref: INTEGER is
      local
	 idx: INTEGER;
      do
	 idx := idx_name_and_type2(us_capacity,fz_30);
	 Result := idx_fieldref2(idx_eiffel_string_class,idx);
      end;

   idx_eiffel_string_storage_fieldref: INTEGER is
      local
	 idx: INTEGER;
      do
	 idx := idx_name_and_type2(us_storage,fz_31);
	 Result := idx_fieldref2(idx_eiffel_string_class,idx);
      end;

feature 

   idx_eiffel_string_descriptor: INTEGER is
      do
	 Result := idx_uft8(jvm_string_descriptor);
      end;

feature {NONE}

   add_last: CP_INFO is
      do
	 if cp.upper > cp_up then
	    cp_up := cp_up + 1;
	    Result := cp.item(cp_up);
	 else
	    !!Result.clear;
	    cp.add_last(Result);
	    cp_up := cp_up + 1;
	 end;
      ensure
	 cp_up = 1 + old cp_up
      end;

   tmp_uft8: STRING is
      once
	 !!Result.make(32);
      end;

   tmp_info: STRING is
      once
	 !!Result.make(32);
      end;

   tmp_info_append_u2(u2: INTEGER) is
      do
	 append_u2(tmp_info,u2);
      end;

feature {NONE}

   jvm_string_descriptor: STRING is
      	 -- Descriptor for class STRING: "L<Package>/string;"
      once
	 !!Result.make(12);
	 Result.extend('L');
	 Result.append(jvm_string_class);
	 Result.extend(';');
      end;

   jvm_string_class: STRING is
      	 -- Fully qualified name for class STRING
      once
	 !!Result.make(12);
	 Result.append(jvm.output_name);
	 Result.extend('/');
	 Result.append(fz_24);
      end;

invariant

   cp_up <= cp.upper;
   
end -- CONSTANT_POOL