+ Objective-C category support (old and new ABI, both external and

implemented in Pascal). See
    http://wiki.freepascal.org/FPC_PasCocoa#Category_declaration for syntax
    details

git-svn-id: trunk@14196 -

.gitattributes

@@ -8963,6 +8963,13 @@ tests/test/tobjc20.pp svneol=native#text/plain
 tests/test/tobjc21.pp svneol=native#text/plain
 tests/test/tobjc22.pp svneol=native#text/plain
 tests/test/tobjc23.pp svneol=native#text/plain
+tests/test/tobjc24.pp svneol=native#text/plain
+tests/test/tobjc25.pp svneol=native#text/plain
+tests/test/tobjc26.pp svneol=native#text/plain
+tests/test/tobjc26a.pp svneol=native#text/plain
+tests/test/tobjc27a.pp svneol=native#text/plain
+tests/test/tobjc27b.pp svneol=native#text/plain
+tests/test/tobjc28.pp svneol=native#text/plain
 tests/test/tobjc3.pp svneol=native#text/plain
 tests/test/tobjc4.pp svneol=native#text/plain
 tests/test/tobjc4a.pp svneol=native#text/plain
@@ -9300,6 +9307,10 @@ tests/test/units/sysutils/tfloattostr.pp svneol=native#text/plain
 tests/test/units/sysutils/tlocale.pp svneol=native#text/plain
 tests/test/units/sysutils/tsscanf.pp svneol=native#text/plain
 tests/test/units/sysutils/tstrtobool.pp svneol=native#text/plain
+tests/test/uobjc24.pp svneol=native#text/plain
+tests/test/uobjc26.pp svneol=native#text/plain
+tests/test/uobjc27a.pp svneol=native#text/plain
+tests/test/uobjc27b.pp svneol=native#text/plain
 tests/test/uobjc7.pp svneol=native#text/plain
 tests/test/uobjcl1.pp svneol=native#text/plain
 tests/test/uprec6.pp svneol=native#text/plain

compiler/msg/errore.msg

@@ -366,7 +366,7 @@ scan_w_multiple_main_name_overrides=02086_W_Overriding name of "main" procedure
 #
 # Parser
 #
-# 03275 is the last used one
+# 03280 is the last used one
 #
 % \section{Parser messages}
 % This section lists all parser messages. The parser takes care of the
@@ -913,11 +913,11 @@ parser_e_no_con_des_in_interfaces=03171_E_Con- and destructors aren't allowed in
 % be used to create a new interface.
 parser_e_no_access_specifier_in_interfaces=03172_E_Access specifiers can't be used in INTERFACEs and OBJCPROTOCOLs
 % The access specifiers \var{public}, \var{private}, \var{protected} and
-% \var{published} can't be used in interfaces and Objective-C protocols because all methods
+% \var{published} can't be used in interfaces, Objective-C protocols and categories because all methods
-% of an interface/protocol must be public.
+% of an interface/protocol/category must be public.
-parser_e_no_vars_in_interfaces=03173_E_An interface or Objective-C protocol cannot contain fields
+parser_e_no_vars_in_interfaces=03173_E_An interface or Objective-C protocol or category cannot contain fields
-% Declarations of fields are not allowed in interfaces and Objective-C protocols. An interface/protocol
+% Declarations of fields are not allowed in interfaces and Objective-C protocols and categories.
-% can contain only methods and properties with method read/write specifiers.
+% An interface/protocol/category can contain only methods and properties with method read/write specifiers.
 parser_e_no_local_proc_external=03174_E_Can't declare local procedure as EXTERNAL
 % Declaring local procedures as external is not possible. Local procedures
 % get hidden parameters that will make the chance of errors very high.
@@ -992,7 +992,7 @@ parser_e_illegal_calling_convention=03195_W_Calling convention directive ignored
 % Some calling conventions are supported only by certain CPUs. I.e. most non-i386 ports support
 % only the standard ABI calling convention of the CPU.
 parser_e_no_object_reintroduce=03196_E_REINTRODUCE can't be used in objects
-% \var{reintroduce} is not supported for objects.
+% \var{reintroduce} is not supported for objects, Objective-C classes and Objective-C protocols.
 parser_e_paraloc_only_one_para=03197_E_Each argument must have its own location
 % If locations for arguments are specified explicitly as it is required by
 % some syscall conventions, each argument must have its own location. Things
@@ -1245,13 +1245,13 @@ parser_e_no_objc_published=03271_E_Objective-C classes cannot have published sec
 parser_f_need_objc=03272_F_This module requires an Objective-C mode switch to be compiled
 % This error indicates the use of Objective-C language features without an Objective-C mode switch
 % active. Enable one via the -M command line switch, or the {\$modeswitch x} directive.
-parser_e_must_use_override_objc=03273_E_Inherited methods can only be overridden in Objective-C, add ``override''.
+parser_e_must_use_override_objc=03273_E_Inherited methods can only be overridden in Objective-C, add "override".
-parser_h_should_use_override_objc=03274_H_Inherited methods can only be overridden in Objective-C, add ``override''.
+parser_h_should_use_override_objc=03274_H_Inherited methods can only be overridden in Objective-C, add "override".
-% It is not possible to ``reintroduce'' methods in Objective-C like in Object Pascal. Methods with the same
+% It is not possible to \var{reintroduce} methods in Objective-C like in Object Pascal. Methods with the same
 % name always map to the same virtual method entry. In order to make this clear in the source code,
-% the compiler always requires the ``override'' directive to be specified when implementing overriding
+% the compiler always requires the \var{override} directive to be specified when implementing overriding
 % Objective-C methods in Pascal. If the implementation is external, this rule is relaxed because Objective-C
-% does not have any ``override''-style keyword (since it's the default and only behaviour in that language),
+% does not have any \var{override}-style keyword (since it's the default and only behaviour in that language),
 % which makes it hard for automated header conversion tools to include it everywhere.
 parser_e_objc_message_name_changed=03275_E_Message name "$1" in inherited class is different from message name "$2" in current class.
 % An overriding Objective-C method cannot have a different message name than an inherited method. The reason
@@ -1260,11 +1260,24 @@ parser_e_objc_message_name_changed=03275_E_Message name "$1" in inherited class
 parser_e_no_objc_unique=03276_E_It is not yet possible to make unique copies of Objective-C types
 % Duplicating an Objective-C type using \var{type x = type y;} is not yet supported. You may be able to
 % obtain the desired effect using \var{type x = objcclass(y) end;} instead.
+parser_e_no_category_as_types=03277_E_Objective-C categories cannot be used as types
+% It is not possible to declare a variable as an instance of an Objective-C category. A
+% category adds methods to the scope of an existing class, but does not define a type by itself.
+parser_e_no_category_override=03278_E_Categories do not override, but replace methods. Use "reintroduce" instead.
+parser_e_must_use_reintroduce_objc=03279_E_Replaced methods can only be reintroduced in Objective-C, add "reintroduce".
+parser_h_should_use_reintroduce_objc=03280_H_Replaced methods can only be reintroduced in Objective-C, add "reintroduce".
+% A category replaces an existing method in an Objective-C class, rather than that it overrides it.
+% Calling an inherited method from an category method will call that method in
+% the extended class' parent, not in the extended class itself. The
+% replaced method in the original class is basically lost, and can no longer be
+% called or referred to. This behaviour corresponds somewhat more closely to
+% \var{reintroduce} than to \var{override} (although in case of \var{reintroduce}
+% in Object Pascal, hidden methods are still reachable via inherited).
 % \end{description}
 #
 # Type Checking
 #
-# 04093 is the last used one
+# 04094 is the last used one
 #
 % \section{Type checking errors}
 % This section lists all errors that can occur when type checking is
@@ -1578,7 +1591,9 @@ type_e_objc_type_unsupported=04092_E_The type "$1" is not supported for interact
 % interfaces) cannot be used as fields of Objective-C classes, cannot be
 % directly passed to Objective-C methods, and cannot be encoded using \var{objc_encode}.
 type_e_class_or_objcclass_type_expected=04093_E_Class or objcclass type expected, but got "$1"
-% It is only possible to create class reference types of \var{class} and
+% It is only possible to create class reference types of \var{class} and \var{objcclass}
+type_e_objcclass_type_expected=04094_E_Objcclass type expected
+% The compiler expected an Objc
 % \var{objcclass} types
 %
 % \end{description}

compiler/msgidx.inc

@@ -364,6 +364,10 @@ const
   parser_h_should_use_override_objc=03274;
   parser_e_objc_message_name_changed=03275;
   parser_e_no_objc_unique=03276;
+  parser_e_no_category_as_types=03277;
+  parser_e_no_category_override=03278;
+  parser_e_must_use_reintroduce_objc=03279;
+  parser_h_should_use_reintroduce_objc=03280;
   type_e_mismatch=04000;
   type_e_incompatible_types=04001;
   type_e_not_equal_types=04002;
@@ -448,6 +452,7 @@ const
   type_e_protocol_type_expected=04091;
   type_e_objc_type_unsupported=04092;
   type_e_class_or_objcclass_type_expected=04093;
+  type_e_objcclass_type_expected=04094;
   sym_e_id_not_found=05000;
   sym_f_internal_error_in_symtablestack=05001;
   sym_e_duplicate_id=05002;
@@ -827,9 +832,9 @@ const
   option_info=11024;
   option_help_pages=11025;
 
-  MsgTxtSize = 54197;
+  MsgTxtSize = 54546;
 
   MsgIdxMax : array[1..20] of longint=(
-    24,87,277,94,71,51,108,22,202,62,
+    24,87,281,95,71,51,108,22,202,62,
     48,20,1,1,1,1,1,1,1,1
   );

compiler/nobj.pas

@@ -281,8 +281,12 @@ implementation
             if (po_virtualmethod in vmtpd.procoptions) and
                (
                 not(po_virtualmethod in pd.procoptions) or
-                { new one has not override }
+                (
-                (is_class_or_interface_or_objc(_class) and not(po_overridingmethod in pd.procoptions))
+                 { new one does not have reintroduce in case of an objccategory }
+                 (is_objccategory(_class) and not(po_reintroduce in pd.procoptions)) or
+                 { new one does not have override in case of objpas/objc class/intf/proto }
+                 (is_class_or_interface_or_objc(_class) and not is_objccategory(_class) and not(po_overridingmethod in pd.procoptions))
+                )
                ) then
               begin
                 if (
@@ -305,12 +309,18 @@ implementation
                             because requiring override everywhere may make
                             automated header translation tools too complex.  }
                           if not(oo_is_external in _class.objectoptions) then
-                            MessagePos1(pd.fileinfo,parser_e_must_use_override_objc,pd.fullprocname(false))
+                            if not is_objccategory(_class) then
+                              MessagePos1(pd.fileinfo,parser_e_must_use_override_objc,pd.fullprocname(false))
+                            else
+                              MessagePos1(pd.fileinfo,parser_e_must_use_reintroduce_objc,pd.fullprocname(false))
                           { there may be a lot of these in auto-translated
                             heaeders, so only calculate the fullprocname if
                             the hint will be shown  }
                           else if CheckVerbosity(V_Hint) then
-                            MessagePos1(pd.fileinfo,parser_h_should_use_override_objc,pd.fullprocname(false));
+                            if not is_objccategory(_class) then
+                              MessagePos1(pd.fileinfo,parser_h_should_use_override_objc,pd.fullprocname(false))
+                            else
+                              MessagePos1(pd.fileinfo,parser_h_should_use_reintroduce_objc,pd.fullprocname(false));
                           { no new entry, but copy the message name if any from
                             the procdef in the parent class }
                           check_msg_str(vmtpd,pd);

compiler/objcgutl.pas

@@ -56,13 +56,16 @@ implementation
     tobjcrttiwriter = class
      protected
       fabi: tobjcabi;
-      classdefs: tfpobjectlist;
+      classdefs,
-      classsyms: tfpobjectlist;
+      catdefs: tfpobjectlist;
+      classsyms,
+      catsyms: tfpobjectlist;
       procedure gen_objc_methods(list: tasmlist; objccls: tobjectdef; out methodslabel: tasmlabel; classmethods, iscategory: Boolean);
       procedure gen_objc_protocol_list(list:TAsmList; protolist: TFPObjectList; out protolistsym: TAsmLabel);
       procedure gen_objc_cat_methods(list:TAsmList; items: TFPObjectList; section: tasmsectiontype;const sectname: string; out listsym: TAsmLabel);
 
       procedure gen_objc_protocol(list:TAsmList; protocol: tobjectdef; out protocollabel: TAsmSymbol);virtual;abstract;
+      procedure gen_objc_category_sections(list:TAsmList; objccat: tobjectdef; out catlabel: TAsmSymbol);virtual;abstract;
       procedure gen_objc_classes_sections(list:TAsmList; objclss: tobjectdef; out classlabel: TAsmSymbol);virtual;abstract;
       procedure gen_objc_info_sections(list: tasmlist);virtual;abstract;
      public
@@ -78,6 +81,7 @@ implementation
      protected
       procedure gen_objc_ivars(list: TAsmList; objccls: tobjectdef; out ivarslabel: TAsmLabel);
       procedure gen_objc_protocol(list:TAsmList; protocol: tobjectdef; out protocollabel: TAsmSymbol);override;
+      procedure gen_objc_category_sections(list:TAsmList; objccat: tobjectdef; out catlabel: TAsmSymbol);override;
       procedure gen_objc_classes_sections(list:TAsmList; objclss: tobjectdef; out classlabel: TAsmSymbol);override;
       procedure gen_objc_info_sections(list: tasmlist);override;
      public
@@ -96,6 +100,7 @@ implementation
 
       procedure gen_objc_ivars(list: TAsmList; objccls: tobjectdef; out ivarslabel: TAsmLabel);
       procedure gen_objc_protocol(list:TAsmList; protocol: tobjectdef; out protocollabel: TAsmSymbol);override;
+      procedure gen_objc_category_sections(list:TAsmList; objccat: tobjectdef; out catlabel: TAsmSymbol);override;
       procedure gen_objc_classes_sections(list:TAsmList; objclss: tobjectdef; out classlabel: TAsmSymbol);override;
       procedure gen_objc_info_sections(list: tasmlist);override;
      public
@@ -277,7 +282,7 @@ procedure tobjcrttiwriter.gen_objc_methods(list: tasmlist; objccls: tobjectdef;
     for i:=0 to objccls.vmtentries.count-1 do
       begin
         def:=pvmtentry(objccls.vmtentries[i])^.procdef;
-        if Assigned(def.procstarttai) and
+        if (def.owner.defowner=objccls) and
            (classmethods = (po_classmethod in def.procoptions)) then
           begin
             defs[mcnt].def:=def;
@@ -290,9 +295,9 @@ procedure tobjcrttiwriter.gen_objc_methods(list: tasmlist; objccls: tobjectdef;
       exit;
 
     if iscategory then
-      new_section(list,clsSectType[classmethods],clsSectName[classmethods],sizeof(ptrint))
+      new_section(list,catSectType[classmethods],catSectName[classmethods],sizeof(ptrint))
     else
-      new_section(list,catSectType[classmethods],catSectName[classmethods],sizeof(ptrint));
+      new_section(list,clsSectType[classmethods],clsSectName[classmethods],sizeof(ptrint));
 
     current_asmdata.getlabel(methodslabel,alt_data);
     list.Concat(tai_label.Create(methodslabel));
@@ -441,9 +446,18 @@ procedure tobjcrttiwriter.gen_objc_rtti_sections(list:TAsmList; st:TSymtable);
         if is_objcclass(def) and
            not(oo_is_external in tobjectdef(def).objectoptions) then
           begin
-            gen_objc_classes_sections(list,tobjectdef(def),sym);
+            if not(oo_is_classhelper in tobjectdef(def).objectoptions) then
-            classsyms.add(sym);
+              begin
-            classdefs.add(def);
+                gen_objc_classes_sections(list,tobjectdef(def),sym);
+                classsyms.add(sym);
+                classdefs.add(def);
+              end
+            else
+              begin
+                gen_objc_category_sections(list,tobjectdef(def),sym);
+                catsyms.add(sym);
+                catdefs.add(def);
+              end
           end;
       end;
   end;
@@ -454,6 +468,8 @@ constructor tobjcrttiwriter.create(_abi: tobjcabi);
     fabi:=_abi;
     classdefs:=tfpobjectlist.create(false);
     classsyms:=tfpobjectlist.create(false);
+    catdefs:=tfpobjectlist.create(false);
+    catsyms:=tfpobjectlist.create(false);
   end;
 
 
@@ -461,6 +477,8 @@ destructor tobjcrttiwriter.destroy;
   begin
     classdefs.free;
     classsyms.free;
+    catdefs.free;
+    catsyms.free;
     inherited destroy;
   end;
 
@@ -584,6 +602,61 @@ procedure tobjcrttiwriter_fragile.gen_objc_protocol(list:TAsmList; protocol: tob
   end;
 
 
+(*
+From Clang:
+
+  struct _objc_category {
+  char *category_name;
+  char *class_name;
+  struct _objc_method_list *instance_methods;
+  struct _objc_method_list *class_methods;
+  struct _objc_protocol_list *protocols;
+  uint32_t size; // <rdar://4585769>
+  struct _objc_property_list *instance_properties;
+  };
+*)
+
+{ Generate rtti for an Objective-C class and its meta-class. }
+procedure tobjcrttiwriter_fragile.gen_objc_category_sections(list:TAsmList; objccat: tobjectdef; out catlabel: TAsmSymbol);
+  var
+    instmthdlist,
+    clsmthdlist,
+    protolistsym  : TAsmLabel;
+    catstrsym,
+    clsstrsym,
+    catsym        : TAsmSymbol;
+  begin
+    { the category name }
+    catstrsym:=objcreatestringpoolentry(objccat.objextname^,sp_objcclassnames,sec_objc_class_names);
+
+    { the name of the class it extends }
+    clsstrsym:=objcreatestringpoolentry(objccat.childof.objextname^,sp_objcclassnames,sec_objc_class_names);
+
+    { generate the methods lists }
+    gen_objc_methods(list,objccat,instmthdlist,false,true);
+    gen_objc_methods(list,objccat,clsmthdlist,true,true);
+
+    { generate implemented protocols list }
+    gen_objc_protocol_list(list,objccat.ImplementedInterfaces,protolistsym);
+
+    { category declaration section }
+    new_section(list,sec_objc_category,'_OBJC_CATEGORY',sizeof(pint));
+    catsym:=current_asmdata.DefineAsmSymbol(objccat.rtti_mangledname(objcclassrtti),AB_LOCAL,AT_DATA);
+    list.Concat(tai_symbol.Create(catsym,0));
+
+    list.Concat(Tai_const.Create_sym(catstrsym));
+    list.Concat(Tai_const.Create_sym(clsstrsym));
+    ConcatSymOrNil(list,instmthdlist);
+    ConcatSymOrNil(list,clsmthdlist);
+    ConcatSymOrNil(list,protolistsym);
+    { size of this structure }
+    list.Concat(Tai_const.Create_32bit(28));
+    { properties, not yet supported }
+    list.Concat(Tai_const.Create_32bit(0));
+
+    catlabel:=catsym;
+  end;
+
 (*
 From Clang:
 
@@ -604,6 +677,8 @@ From Clang:
   };
 *)
 
+
+
 { Generate rtti for an Objective-C class and its meta-class. }
 procedure tobjcrttiwriter_fragile.gen_objc_classes_sections(list:TAsmList; objclss: tobjectdef; out classlabel: TAsmSymbol);
   const
@@ -705,7 +780,7 @@ procedure tobjcrttiwriter_fragile.gen_objc_classes_sections(list:TAsmList; objcl
     clssym:=current_asmdata.DefineAsmSymbol(objclss.rtti_mangledname(objcclassrtti),AB_LOCAL,AT_DATA);
     list.Concat(tai_symbol.Create(clssym,0));
 
-    { for class declaration: the is points to the meta-class declaration }
+    { for class declaration: the isa points to the meta-class declaration }
     list.Concat(Tai_const.Create_sym(metasym));
     { pointer to the super_class name if any, nil otherwise }
     if assigned(superStrSym) then
@@ -752,7 +827,8 @@ procedure tobjcrttiwriter_fragile.gen_objc_info_sections(list: tasmlist);
     parent: tobjectdef;
     superclasses: tfpobjectlist;
   begin
-    if (classsyms.count<>0) then
+    if (classsyms.count<>0) or
+       (catsyms.count<>0) then
       begin
         new_section(list,sec_objc_symbols,'_OBJC_SYMBOLS',sizeof(pint));
         sym := current_asmdata.DefineAsmSymbol(target_asm.labelprefix+'_OBJC_SYMBOLS_$',AB_LOCAL,AT_DATA);
@@ -766,11 +842,13 @@ procedure tobjcrttiwriter_fragile.gen_objc_info_sections(list: tasmlist);
         { From Clang: number of defined classes }
         list.Concat(Tai_const.Create_16bit(classsyms.count));
         { From Clang: number of defined categories }
-        list.Concat(Tai_const.Create_16bit(0));
+        list.Concat(Tai_const.Create_16bit(catsyms.count));
         { first all classes }
         for i:=0 to classsyms.count-1 do
           list.Concat(Tai_const.Create_sym(tasmsymbol(classsyms[i])));
         { then all categories }
+        for i:=0 to catsyms.count-1 do
+          list.Concat(Tai_const.Create_sym(tasmsymbol(catsyms[i])));
      end
     else
       sym:=nil;
@@ -801,10 +879,25 @@ procedure tobjcrttiwriter_fragile.gen_objc_info_sections(list: tasmlist);
             superclasses.add(parent);
           end;
       end;
+    for i:=0 to catdefs.count-1 do
+      begin
+        parent:=tobjectdef(catdefs[i]).childof;
+        { warning: linear search, performance hazard if large number of subclasses }
+        if assigned(parent) and
+           (superclasses.indexof(parent)=-1) then
+          begin
+            list.concat(tai_directive.create(asd_lazy_reference,'.objc_class_name_'+parent.objextname^));
+            superclasses.add(parent);
+          end;
+      end;
     superclasses.free;
-    { reference symbols for all classes defined in this unit }
+    { reference symbols for all classes and categories defined in this unit }
     for i:=0 to classdefs.count-1 do
       list.concat(tai_symbol.Createname_global_value('.objc_class_name_'+tobjectdef(classdefs[i]).objextname^,AT_DATA,0,0));
+    for i:=0 to catdefs.count-1 do
+      list.concat(tai_symbol.Createname_global_value('.objc_category_name_'+
+        tobjectdef(catdefs[i]).childof.objextname^+'_'+
+        tobjectdef(catdefs[i]).objextname^,AT_DATA,0,0));
   end;
 
 
@@ -1043,6 +1136,55 @@ procedure tobjcrttiwriter_nonfragile.gen_objc_protocol(list: tasmlist; protocol:
     list.Concat(tai_directive.Create(asd_weak_definition,listsym.name));
   end;
 
+(*
+From Clang:
+/// struct _category_t {
+///   const char * const name;
+///   struct _class_t *const cls;
+///   const struct _method_list_t * const instance_methods;
+///   const struct _method_list_t * const class_methods;
+///   const struct _protocol_list_t * const protocols;
+///   const struct _prop_list_t * const properties;
+/// }
+*)
+procedure tobjcrttiwriter_nonfragile.gen_objc_category_sections(list:TAsmList; objccat: tobjectdef; out catlabel: TAsmSymbol);
+  var
+    instmthdlist,
+    clsmthdlist,
+    protolistsym  : TAsmLabel;
+    catstrsym,
+    clssym,
+    catsym        : TAsmSymbol;
+  begin
+    { the category name }
+    catstrsym:=objcreatestringpoolentry(objccat.objextname^,sp_objcclassnames,sec_objc_class_names);
+
+    { the class it extends }
+    clssym:=current_asmdata.RefAsmSymbol(objccat.childof.rtti_mangledname(objcclassrtti));
+
+    { generate the methods lists }
+    gen_objc_methods(list,objccat,instmthdlist,false,true);
+    gen_objc_methods(list,objccat,clsmthdlist,true,true);
+
+    { generate implemented protocols list }
+    gen_objc_protocol_list(list,objccat.ImplementedInterfaces,protolistsym);
+
+    { category declaration section }
+    new_section(list,sec_objc_const,'_OBJC_CATEGORY',sizeof(pint));
+    catsym:=current_asmdata.DefineAsmSymbol(objccat.rtti_mangledname(objcclassrtti),AB_LOCAL,AT_DATA);
+    list.Concat(tai_symbol.Create(catsym,0));
+
+    list.Concat(Tai_const.Create_sym(catstrsym));
+    list.Concat(Tai_const.Create_sym(clssym));
+    ConcatSymOrNil(list,instmthdlist);
+    ConcatSymOrNil(list,clsmthdlist);
+    ConcatSymOrNil(list,protolistsym);
+    { properties, not yet supported }
+    list.Concat(Tai_const.Create_pint(0));
+
+    catlabel:=catsym;
+  end;
+
 
 (*
 From Clang:
@@ -1363,45 +1505,58 @@ procedure tobjcrttiwriter_nonfragile.addclasslist(list: tasmlist; section: tasms
 
 procedure tobjcrttiwriter_nonfragile.gen_objc_info_sections(list: tasmlist);
 
+  function collectnonlazyclasses(classes: tfpobjectlist): tfpobjectlist;
+    var
+      symentry : tsym;
+      procdef  : tprocdef;
+      i,j      : longint;
+    begin
+      { non-lazy classes are all classes that define a class method with the
+        selector called "load" (simply inheriting this class method is not enough,
+        they have to implement it themselves)
+
+        -- TODO: this currently only works if the Pascal identifier is also 'load'! }
+      result:=tfpobjectlist.create(false);
+      for i:=0 to classes.count-1 do
+        begin
+          symentry:=tsym(tobjectsymtable(tobjectdef(classes[i]).symtable).find('LOAD'));
+          if assigned(symentry) and
+             (symentry.typ=procsym) then
+            begin
+              for j:=0 to tprocsym(symentry).ProcdefList.count do
+                begin
+                  procdef:=tprocdef(tprocsym(symentry).ProcdefList[0]);
+                  if ((po_classmethod in procdef.procoptions) and
+                      (procdef.messageinf.str^='load')) then
+                    begin
+                      result.add(classes[i]);
+                      break;
+                    end;
+                end;
+            end;
+        end;
+    end;
+
   var
-    i,j            : longint;
+    nonlazyclasses,
-    symentry       : tsym;
+    nonlazycategories : tfpobjectlist;
-    procdef        : tprocdef;
-    nonlazyclasses : tfpobjectlist;
   begin
-    if (classsyms.count=0) then
+    if (classdefs.count=0) and
+       (catdefs.count=0) then
       exit;
 
-    { non-lazy classes are all classes that define a class method with the
+    nonlazyclasses:=collectnonlazyclasses(classdefs);
-      selector called "load" (simply inheriting this class method is not enough,
+    nonlazycategories:=collectnonlazyclasses(catdefs);
-      they have to implement it themselves)
-
-      -- TODO: this currently only works if the Pascal identifier is also 'load'! }
-    nonlazyclasses:=tfpobjectlist.create(false);
-    for i:=0 to classdefs.count-1 do
-      begin
-        symentry:=tsym(tobjectsymtable(tobjectdef(classdefs[i]).symtable).find('LOAD'));
-        if assigned(symentry) and
-           (symentry.typ=procsym) then
-          begin
-            for j:=0 to tprocsym(symentry).ProcdefList.count do
-              begin
-                procdef:=tprocdef(tprocsym(symentry).ProcdefList[0]);
-                if ((po_classmethod in procdef.procoptions) and
-                    (procdef.messageinf.str^='load')) then
-                  begin
-                    nonlazyclasses.add(classdefs[i]);
-                    break;
-                  end;
-              end;
-          end;
-      end;
 
     { this list has to include all classes, also the non-lazy ones }
     addclasslist(list,sec_objc_classlist,target_asm.labelprefix+'_OBJC_LABEL_CLASS_$',classdefs);
     addclasslist(list,sec_objc_nlclasslist,target_asm.labelprefix+'_OBJC_LABEL_NONLAZY_CLASS_$',nonlazyclasses);
-    { TODO: category and non-lazy category lists }
+    { category and non-lazy category lists }
+    addclasslist(list,sec_objc_catlist,target_asm.labelprefix+'_OBJC_LABEL_CATEGORY_$',catdefs);
+    addclasslist(list,sec_objc_nlcatlist,target_asm.labelprefix+'_OBJC_LABEL_NONLAZY_CATEGORY_$',nonlazycategories);
 
+    nonlazyclasses.free;
+    nonlazycategories.free;
     { the non-fragile abi doesn't have any module info, nor lazy references
       to used classes or to parent classes }
   end;
@@ -1431,7 +1586,7 @@ procedure MaybeGenerateObjectiveCImageInfo(globalst, localst: tsymtable);
         current_asmdata.asmlists[al_objc_data].concat(Tai_symbol.Createname(target_asm.labelprefix+'_OBJC_IMAGE_INFO',AT_LABEL,sizeof(pint)));
         current_asmdata.asmlists[al_objc_data].concat(Tai_const.Create_64bit(0));
 
-        { generate rtti for all obj-c classes, protocols and categories (todo)
+        { generate rtti for all obj-c classes, protocols and categories
           defined in this module. }
         if not(target_info.system in system_objc_nfabi) then
           objcrttiwriter:=tobjcrttiwriter_fragile.create

compiler/objcutil.pas

@@ -117,11 +117,22 @@ end;
                        objcsuperclassnode
 *******************************************************************}
 
+    function objcloadbasefield(n: tnode; const fieldname: string): tnode;
+      var
+        vs         : tsym;
+      begin
+        result:=ctypeconvnode.create_internal(cderefnode.create(ctypeconvnode.create_internal(n,voidpointertype)),objc_objecttype);
+        vs:=tsym(tabstractrecorddef(objc_objecttype).symtable.Find(fieldname));
+        if not assigned(vs) or
+           (vs.typ<>fieldvarsym) then
+          internalerror(200911301);
+        result:=csubscriptnode.create(vs,result);
+      end;
+
+
     function objcsuperclassnode(def: tdef): tnode;
       var
         para       : tcallparanode;
-        class_type : tdef;
-        vs         : tsym;
       begin
         { only valid for Objective-C classes and classrefs }
         if not is_objcclass(def) and
@@ -131,11 +142,30 @@ end;
           requires extra node types. Maybe later. }
         if is_objcclassref(def) then
           begin
-            para:=ccallparanode.create(cstringconstnode.createstr(tobjectdef(tclassrefdef(def).pointeddef).objextname^),nil);
+            if (oo_is_classhelper in tobjectdef(tclassrefdef(def).pointeddef).objectoptions) then
-            result:=ccallnode.createinternfromunit('OBJC','OBJC_GETMETACLASS',para);
+              begin
+                { in case we are in a category method, we need the metaclass of the
+                  superclass class extended by this category (= metaclass of superclass of superclass) }
+                result:=cloadvmtaddrnode.create(ctypenode.create(tobjectdef(tclassrefdef(def).pointeddef).childof.childof));
+                result:=objcloadbasefield(result,'ISA');
+                typecheckpass(result);
+                { we're done }
+                exit;
+              end
+            else
+              begin
+                { otherwise we need the superclass of the metaclass }
+                para:=ccallparanode.create(cstringconstnode.createstr(tobjectdef(tclassrefdef(def).pointeddef).objextname^),nil);
+                result:=ccallnode.createinternfromunit('OBJC','OBJC_GETMETACLASS',para);
+              end
           end
         else
-          result:=cloadvmtaddrnode.create(ctypenode.create(def));
+          begin
+            if not(oo_is_classhelper in tobjectdef(def).objectoptions) then
+              result:=cloadvmtaddrnode.create(ctypenode.create(def))
+            else
+              result:=cloadvmtaddrnode.create(ctypenode.create(tobjectdef(def).childof))
+          end;
 
 {$if defined(onlymacosx10_6) or defined(arm) }
         { For the non-fragile ABI, the superclass send2 method itself loads the
@@ -145,15 +175,7 @@ end;
             (but also on all iPhone SDK revisions we support) }
         if not(target_info.system in system_objc_nfabi) then
 {$endif onlymacosx10_6 or arm}
-          begin
+          result:=objcloadbasefield(result,'SUPERCLASS');
-            class_type:=search_named_unit_globaltype('OBJC','OBJC_OBJECT').typedef;
-            result:=ctypeconvnode.create_internal(cderefnode.create(ctypeconvnode.create_internal(result,voidpointertype)),class_type);
-            vs:=tsym(tabstractrecorddef(class_type).symtable.Find('SUPERCLASS'));
-            if not assigned(vs) or
-               (vs.typ<>fieldvarsym) then
-              internalerror(200909301);
-            result:=csubscriptnode.create(vs,result);
-          end;
         typecheckpass(result);
       end;
 

compiler/pdecl.pas

@@ -440,7 +440,8 @@ implementation
                      (token=_INTERFACE) or
                      (token=_DISPINTERFACE) or
                      (token=_OBJCCLASS) or
-                     (token=_OBJCPROTOCOL)) and
+                     (token=_OBJCPROTOCOL) or
+                     (token=_OBJCCATEGORY)) and
                     (assigned(ttypesym(sym).typedef)) and
                     is_class_or_interface_or_dispinterface_or_objc(ttypesym(sym).typedef) and
                     (oo_is_forward in tobjectdef(ttypesym(sym).typedef).objectoptions) then
@@ -455,7 +456,8 @@ implementation
                           objecttype:=odt_interfacecorba;
                       _DISPINTERFACE :
                         objecttype:=odt_dispinterface;
-                      _OBJCCLASS :
+                      _OBJCCLASS,
+                      _OBJCCATEGORY :
                         objecttype:=odt_objcclass;
                       _OBJCPROTOCOL :
                         objecttype:=odt_objcprotocol;

compiler/pdecobj.pas

@@ -313,15 +313,20 @@ implementation
         hasparentdefined:=false;
 
         { reads the parent class }
-        if try_to_consume(_LKLAMMER) then
+        if (token=_LKLAMMER) or
+           is_objccategory(current_objectdef) then
           begin
+            consume(_LKLAMMER);
             { use single_type instead of id_type for specialize support }
             single_type(hdef,false,false);
             if (not assigned(hdef)) or
                (hdef.typ<>objectdef) then
               begin
                 if assigned(hdef) then
-                  Message1(type_e_class_type_expected,hdef.typename);
+                  Message1(type_e_class_type_expected,hdef.typename)
+                else if is_objccategory(current_objectdef) then
+                  { a category must specify the class to extend }
+                  Message(type_e_objcclass_type_expected);
               end
             else
               begin
@@ -358,13 +363,20 @@ implementation
                      if not(is_cppclass(childof)) then
                        Message(parser_e_mix_of_classes_and_objects);
                    odt_objcclass:
-                     if not(is_objcclass(childof)) then
+                     if not(is_objcclass(childof) or
+                        is_objccategory(childof)) then
                        begin
                          if is_objcprotocol(childof) then
                            begin
-                             intfchildof:=childof;
+                             if not(oo_is_classhelper in current_objectdef.objectoptions) then
-                             childof:=nil;
+                               begin
-                             CGMessage(parser_h_no_objc_parent);
+                                 intfchildof:=childof;
+                                 childof:=nil;
+                                 CGMessage(parser_h_no_objc_parent);
+                               end
+                             else
+                               { a category must specify the class to extend }
+                               CGMessage(type_e_objcclass_type_expected);
                            end
                          else
                            Message(parser_e_mix_of_classes_and_objects);
@@ -562,7 +574,7 @@ implementation
                   _PRIVATE :
                     begin
                       if is_interface(current_objectdef) or
-                         is_objcprotocol(current_objectdef) then
+                         is_objc_protocol_or_category(current_objectdef) then
                         Message(parser_e_no_access_specifier_in_interfaces);
                        consume(_PRIVATE);
                        current_objectdef.symtable.currentvisibility:=vis_private;
@@ -572,7 +584,7 @@ implementation
                    _PROTECTED :
                      begin
                        if is_interface(current_objectdef) or
-                          is_objcprotocol(current_objectdef) then
+                          is_objc_protocol_or_category(current_objectdef) then
                          Message(parser_e_no_access_specifier_in_interfaces);
                        consume(_PROTECTED);
                        current_objectdef.symtable.currentvisibility:=vis_protected;
@@ -582,7 +594,7 @@ implementation
                    _PUBLIC :
                      begin
                        if is_interface(current_objectdef) or
-                          is_objcprotocol(current_objectdef) then
+                          is_objc_protocol_or_category(current_objectdef) then
                          Message(parser_e_no_access_specifier_in_interfaces);
                        consume(_PUBLIC);
                        current_objectdef.symtable.currentvisibility:=vis_public;
@@ -593,8 +605,7 @@ implementation
                        { we've to check for a pushlished section in non-  }
                        { publishable classes later, if a real declaration }
                        { this is the way, delphi does it                  }
-                       if is_interface(current_objectdef) or
+                       if is_interface(current_objectdef) then
-                          is_objcprotocol(current_objectdef) then
                          Message(parser_e_no_access_specifier_in_interfaces);
                        { Objective-C classes do not support "published",
                          as basically everything is published.  }
@@ -607,7 +618,7 @@ implementation
                    _STRICT :
                      begin
                        if is_interface(current_objectdef) or
-                          is_objcprotocol(current_objectdef) then
+                          is_objc_protocol_or_category(current_objectdef) then
                           Message(parser_e_no_access_specifier_in_interfaces);
                         consume(_STRICT);
                         if token=_ID then
@@ -638,7 +649,7 @@ implementation
                         if object_member_blocktype=bt_general then
                           begin
                             if is_interface(current_objectdef) or
-                               is_objcprotocol(current_objectdef) then
+                               is_objc_protocol_or_category(current_objectdef) then
                               Message(parser_e_no_vars_in_interfaces);
 
                             if (current_objectdef.symtable.currentvisibility=vis_published) and
@@ -871,6 +882,13 @@ implementation
           end
         else
           begin
+            { change objccategories into objcclass helpers }
+            if (objecttype=odt_objccategory) then
+              begin
+                current_objectdef.objecttype:=odt_objcclass;
+                include(current_objectdef.objectoptions,oo_is_classhelper);
+              end;
+
             { parse list of options (abstract / sealed) }
             parse_object_options;
 

compiler/pdecsub.pas

@@ -1413,7 +1413,9 @@ begin
   if pd.typ<>procdef then
     internalerror(2003042611);
   if not(is_class_or_interface_or_objc(tprocdef(pd)._class)) then
-    Message(parser_e_no_object_override);
+    Message(parser_e_no_object_override)
+  else if is_objccategory(tprocdef(pd)._class) then
+    Message(parser_e_no_category_override);
 end;
 
 procedure pd_overload(pd:tabstractprocdef);
@@ -1483,7 +1485,8 @@ procedure pd_reintroduce(pd:tabstractprocdef);
 begin
   if pd.typ<>procdef then
     internalerror(200401211);
-  if not(is_class_or_interface_or_object(tprocdef(pd)._class)) then
+  if not(is_class_or_interface_or_object(tprocdef(pd)._class)) and
+     not(is_objccategory(tprocdef(pd)._class)) then
     Message(parser_e_no_object_reintroduce);
 end;
 
@@ -2036,7 +2039,7 @@ const
       mutexclpo     : [po_external]
     ),(
       idtok:_REINTRODUCE;
-      pd_flags : [pd_interface,pd_object,pd_notobjintf];
+      pd_flags : [pd_interface,pd_object,pd_notobjintf,pd_objcclass];
       handler  : @pd_reintroduce;
       pocall   : pocall_none;
       pooption : [po_reintroduce];

compiler/ptype.pas

@@ -493,7 +493,12 @@ implementation
               begin
                 Message(parser_e_no_generics_as_types);
                 def:=generrordef;
-              end;
+              end
+            else if is_objccategory(def) then
+              begin
+                Message(parser_e_no_category_as_types);
+                def:=generrordef
+              end
           end;
       end;
 
@@ -622,7 +627,12 @@ implementation
                          begin
                            Message(parser_e_no_generics_as_types);
                            def:=generrordef;
-                         end;
+                         end
+                       else if is_objccategory(def) then
+                         begin
+                           Message(parser_e_no_category_as_types);
+                           def:=generrordef
+                         end
                      end;
                  end
                else
@@ -1023,6 +1033,14 @@ implementation
                 consume(token);
                 def:=object_dec(odt_objcprotocol,name,genericdef,genericlist,nil);
                end;
+            _OBJCCATEGORY :
+               begin
+                if not(m_objectivec1 in current_settings.modeswitches) then
+                  Message(parser_f_need_objc);
+
+                consume(token);
+                def:=object_dec(odt_objccategory,name,genericdef,genericlist,nil);
+               end;
             _OBJECT :
               begin
                 consume(token);

compiler/symconst.pas

@@ -117,6 +117,9 @@ const
   paranr_syscall_legacy   = high(word)-2;
   paranr_result_leftright = high(word)-1;
 
+  { prefix for names of class helper procsyms added to regular symtables }
+  class_helper_prefix = 'CH$';
+
 
 type
   { keep this in sync with TIntfFlag in rtl/objpas/typinfo.pp }
@@ -302,7 +305,8 @@ type
     odt_cppclass,
     odt_dispinterface,
     odt_objcclass,
-    odt_objcprotocol
+    odt_objcprotocol,
+    odt_objccategory { note that these are changed into odt_class afterwards }
   );
 
   { Variations in interfaces implementation }
@@ -335,7 +339,8 @@ type
     oo_has_enumerator_movenext,
     oo_has_enumerator_current,
     oo_is_external,       { the class is externally implemented (objcclass, cppclass) }
-    oo_is_anonymous       { the class is only formally defined in this module (objcclass x = class; external;) }
+    oo_is_anonymous,      { the class is only formally defined in this module (objcclass x = class; external;) }
+    oo_is_classhelper     { objcclasses that represent categories, and Delpi-style class helpers, are marked like this }
   );
   tobjectoptions=set of tobjectoption;
 

compiler/symdef.pas

@@ -685,6 +685,7 @@ interface
        objc_superclasstype,
        objc_idtype,
        objc_seltype         : tpointerdef;
+       objc_objecttype      : trecorddef;
        { base type of @protocol(protocolname) Objective-C statements }
        objc_protocoltype    : tobjectdef;
 
@@ -739,7 +740,9 @@ interface
     function is_objcclass(def: tdef): boolean;
     function is_objcclassref(def: tdef): boolean;
     function is_objcprotocol(def: tdef): boolean;
+    function is_objccategory(def: tdef): boolean;
     function is_objc_class_or_protocol(def: tdef): boolean;
+    function is_objc_protocol_or_category(def: tdef): boolean;
     function is_class_or_interface(def: tdef): boolean;
     function is_class_or_interface_or_objc(def: tdef): boolean;
     function is_class_or_interface_or_object(def: tdef): boolean;
@@ -3582,12 +3585,19 @@ implementation
 
 
     function  tprocdef.objcmangledname : string;
+      var
+        manglednamelen: longint;
+        iscatmethod   : boolean;
       begin
         if not (po_msgstr in procoptions) then
           internalerror(2009030901);
         { we may very well need longer strings to handle these... }
-        if ((255-length(tobjectdef(procsym.owner.defowner).objextname^)
+        manglednamelen:=length(tobjectdef(procsym.owner.defowner).objextname^)+
-             -length('+"[ ]"')-length(messageinf.str^)) < 0) then
+          length('+"[ ]"')+length(messageinf.str^);
+        iscatmethod:=oo_is_classhelper in tobjectdef(procsym.owner.defowner).objectoptions;
+        if (iscatmethod) then
+          inc(manglednamelen,length(tobjectdef(procsym.owner.defowner).childof.objextname^)+length('()'));
+        if manglednamelen>255 then
           Message1(parser_e_objc_message_name_too_long,messageinf.str^);
         if not(po_classmethod in procoptions) then
           result:='"-['
@@ -3596,9 +3606,12 @@ implementation
         { quotes are necessary because the +/- otherwise confuse the assembler
           into expecting a number
         }
-        result:=
+        if iscatmethod then
-          result+tobjectdef(procsym.owner.defowner).objextname^+' '+
+          result:=result+tobjectdef(procsym.owner.defowner).childof.objextname^+'(';
-          messageinf.str^+']"';
+        result:=result+tobjectdef(procsym.owner.defowner).objextname^;
+        if iscatmethod then
+          result:=result+')';
+        result:=result+' '+messageinf.str^+']"';
       end;
 
 
@@ -4082,6 +4095,36 @@ implementation
       end;
 
 
+    procedure create_class_helper_for_procdef(def: tobject; arg: pointer);
+      var
+        pd: tprocdef absolute def;
+        st: tsymtable;
+        psym: tsym;
+        nname: TIDString;
+      begin
+        if (tdef(def).typ<>procdef) then
+          exit;
+        { pd.owner = objcclass symtable -> defowner = objcclassdef ->
+          owner = symtable in which objcclassdef is defined
+        }
+        st:=pd.owner.defowner.owner;
+        nname:=class_helper_prefix+tprocsym(pd.procsym).name;
+        { check for an existing procsym with our special name }
+        psym:=tsym(st.find(nname));
+        if not assigned(psym) then
+          begin
+            psym:=tprocsym.create(nname);
+            { avoid warning about this symbol being unused }
+            psym.IncRefCount;
+            st.insert(psym,true);
+          end
+        else if (psym.typ<>procsym) then
+          internalerror(2009111501);
+        { add ourselves to this special procsym }
+        tprocsym(psym).procdeflist.add(def);
+      end;
+
+
     procedure tobjectdef.buildderefimpl;
       begin
          inherited buildderefimpl;
@@ -4095,6 +4138,10 @@ implementation
          inherited derefimpl;
          if not (df_copied_def in defoptions) then
            tstoredsymtable(symtable).derefimpl;
+         { the procdefs are not owned by the class helper procsyms, so they
+           are not stored/restored either -> re-add them here }
+         if (oo_is_classhelper in objectoptions) then
+           symtable.DefList.ForEachCall(@create_class_helper_for_procdef,nil);
       end;
 
 
@@ -4385,9 +4432,15 @@ implementation
                     begin
                       case rt of
                         objcclassrtti:
-                          result:=result+'_OBJC_CLASS_';
+                          if not(oo_is_classhelper in objectoptions) then
+                            result:=result+'_OBJC_CLASS_'
+                          else
+                            result:=result+'_OBJC_CATEGORY_';
                         objcmetartti:
-                          result:=result+'_OBJC_METACLASS_';
+                          if not(oo_is_classhelper in objectoptions) then
+                            result:=result+'_OBJC_METACLASS_'
+                          else
+                            internalerror(2009111511);
                         else
                          internalerror(2009092302);
                       end;
@@ -4401,9 +4454,15 @@ implementation
                 case objecttype of
                   odt_objcclass:
                     begin
+                      if (oo_is_classhelper in objectoptions) and
+                         (rt<>objcclassrtti) then
+                        internalerror(2009111512);
                       case rt of
                         objcclassrtti:
-                          result:='_OBJC_CLASS_$_';
+                          if not(oo_is_classhelper in objectoptions) then
+                            result:='_OBJC_CLASS_$_'
+                          else
+                            result:='_OBJC_$_CATEGORY_';
                         objcmetartti:
                           result:='_OBJC_METACLASS_$_';
                         objcclassrortti:
@@ -4656,35 +4715,43 @@ implementation
       begin
         if (def.typ=procdef) then
           begin
+            { add all messages also under a dummy name to the symtable in
+              which the objcclass/protocol/category is declared, so they can
+              be called via id.<name>
+            }
+            create_class_helper_for_procdef(pd,nil);
+
             { we have to wait until now to set the mangled name because it
               depends on the (possibly external) class name, which is defined
               at the very end.  }
-            if (po_msgstr in pd.procoptions) then
+            if not(po_msgstr in pd.procoptions) then
               begin
-                { Mangled name is already set in case this is a copy of
+                CGMessagePos(pd.fileinfo,parser_e_objc_requires_msgstr);
-                  another type.  }
+                { recover to avoid internalerror later on }
-                if not(po_has_mangledname in pd.procoptions) then
+                include(pd.procoptions,po_msgstr);
-                  begin
+                pd.messageinf.str:=stringdup('MissingDeclaration');
-                    { check whether the number of formal parameters is correct }
+              end;
-                    paracount:=0;
+            { Mangled name is already set in case this is a copy of
-                    for i:=1 to length(pd.messageinf.str^) do
+              another type.  }
-                      if pd.messageinf.str^[i]=':' then
+            if not(po_has_mangledname in pd.procoptions) then
-                        inc(paracount);
+              begin
-                    for i:=0 to pd.paras.count-1 do
+                { check whether the number of formal parameters is correct }
-                      if not(vo_is_hidden_para in tparavarsym(pd.paras[i]).varoptions) and
+                paracount:=0;
-                         not is_array_of_const(tparavarsym(pd.paras[i]).vardef) then
+                for i:=1 to length(pd.messageinf.str^) do
-                        dec(paracount);
+                  if pd.messageinf.str^[i]=':' then
-                    if (paracount<>0) then
+                    inc(paracount);
-                      MessagePos(pd.fileinfo,sym_e_objc_para_mismatch);
+                for i:=0 to pd.paras.count-1 do
+                  if not(vo_is_hidden_para in tparavarsym(pd.paras[i]).varoptions) and
+                     not is_array_of_const(tparavarsym(pd.paras[i]).vardef) then
+                    dec(paracount);
+                if (paracount<>0) then
+                  MessagePos(pd.fileinfo,sym_e_objc_para_mismatch);
 
-                    pd.setmangledname(pd.objcmangledname);
+                pd.setmangledname(pd.objcmangledname);
-                  end
-                else
-                  { all checks already done }
-                  exit;
               end
             else
-              MessagePos(pd.fileinfo,parser_e_objc_requires_msgstr);
+              { all checks already done }
+              exit;
             if not(oo_is_external in pd._class.objectoptions) then
               begin
                 if (po_varargs in pd.procoptions) then
@@ -5065,6 +5132,18 @@ implementation
       end;
 
 
+    function is_objccategory(def: tdef): boolean;
+      begin
+        result:=
+          assigned(def) and
+          (def.typ=objectdef) and
+          { if used as a forward type }
+          ((tobjectdef(def).objecttype=odt_objccategory) or
+          { if used as after it has been resolved }
+           ((tobjectdef(def).objecttype=odt_objcclass) and
+            (oo_is_classhelper in tobjectdef(def).objectoptions)));
+      end;
+
     function is_objc_class_or_protocol(def: tdef): boolean;
       begin
          result:=
@@ -5074,6 +5153,17 @@ implementation
       end;
 
 
+    function is_objc_protocol_or_category(def: tdef): boolean;
+      begin
+         result:=
+           assigned(def) and
+           (def.typ=objectdef) and
+           ((tobjectdef(def).objecttype = odt_objcprotocol) or
+            ((tobjectdef(def).objecttype = odt_objcclass) and
+             (oo_is_classhelper in tobjectdef(def).objectoptions)));
+      end;
+
+
     function is_class_or_interface(def: tdef): boolean;
       begin
         result:=
@@ -5125,6 +5215,7 @@ implementation
         objc_superclasstype:=tpointerdef(search_named_unit_globaltype('OBJC','POBJC_SUPER').typedef);
         objc_idtype:=tpointerdef(search_named_unit_globaltype('OBJC','ID').typedef);
         objc_seltype:=tpointerdef(search_named_unit_globaltype('OBJC','SEL').typedef);
+        objc_objecttype:=trecorddef(search_named_unit_globaltype('OBJC','OBJC_OBJECT').typedef);
       end;
 
 

compiler/symtable.pas

@@ -204,6 +204,7 @@ interface
     function  search_class_member(pd : tobjectdef;const s : string):tsym;
     function  search_assignment_operator(from_def,to_def:Tdef):Tprocdef;
     function  search_enumerator_operator(type_def:Tdef):Tprocdef;
+    function  search_class_helper(pd : tobjectdef;const s : string; out srsym: tsym; out srsymtable: tsymtable):boolean;
     {Looks for macro s (must be given in upper case) in the macrosymbolstack, }
     {and returns it if found. Returns nil otherwise.}
     function  search_macro(const s : string):tsym;
@@ -1674,6 +1675,16 @@ implementation
                     exit;
                   end;
               end;
+            { also search for class helpers }
+            if (srsymtable.symtabletype=objectsymtable) and
+               is_objcclass(tdef(srsymtable.defowner)) then
+              begin
+                if search_class_helper(tobjectdef(srsymtable.defowner),s,srsym,srsymtable) then
+                  begin
+                    result:=true;
+                    exit;
+                  end;
+              end;
             stackitem:=stackitem^.next;
           end;
         srsym:=nil;
@@ -1810,7 +1821,9 @@ implementation
     function searchsym_in_class(classh,contextclassh:tobjectdef;const s : TIDString;out srsym:tsym;out srsymtable:TSymtable):boolean;
       var
         hashedid : THashedIDString;
+        orgclass : tobjectdef;
       begin
+        orgclass:=classh;
         { The contextclassh is used for visibility. The classh must be equal to
           or be a parent of contextclassh. E.g. for inherited searches the classh is the
           parent. }
@@ -1832,8 +1845,13 @@ implementation
               end;
             classh:=classh.childof;
           end;
-        srsym:=nil;
+        if is_objcclass(orgclass) then
-        srsymtable:=nil;
+          result:=search_class_helper(orgclass,s,srsym,srsymtable)
+        else
+          begin
+            srsym:=nil;
+            srsymtable:=nil;
+          end;
       end;
 
 
@@ -1993,8 +2011,6 @@ implementation
 
     function search_named_unit_globaltype(const unitname, typename: TIDString): ttypesym;
       var
-        contextobjdef : tobjectdef;
-        stackitem  : psymtablestackitem;
         srsymtable: tsymtable;
         sym: tsym;
       begin
@@ -2012,14 +2028,71 @@ implementation
       end;
 
 
+    function search_class_helper(pd : tobjectdef;const s : string; out srsym: tsym; out srsymtable: tsymtable):boolean;
+      var
+        hashedid   : THashedIDString;
+        stackitem  : psymtablestackitem;
+        i          : longint;
+      begin
+        hashedid.id:=class_helper_prefix+s;
+        stackitem:=symtablestack.stack;
+        while assigned(stackitem) do
+          begin
+            srsymtable:=stackitem^.symtable;
+            srsym:=tsym(srsymtable.FindWithHash(hashedid));
+            if assigned(srsym) then
+              begin
+                if not(srsymtable.symtabletype in [globalsymtable,staticsymtable]) or
+                   not(srsym.owner.symtabletype in [globalsymtable,staticsymtable]) or
+                   (srsym.typ<>procsym) then
+                  internalerror(2009111505);
+                { check whether this procsym includes a helper for this particular class }
+                for i:=0 to tprocsym(srsym).procdeflist.count-1 do
+                  begin
+                    { does pd inherit from (or is the same as) the class
+                      that this method's category extended?
+                    }
+                    if pd.is_related(tobjectdef(tprocdef(tprocsym(srsym).procdeflist[i]).owner.defowner).childof) then
+                      begin
+                        { no need to keep looking. There might be other
+                          categories that extend this, a parent or child
+                          class with a method with the same name (either
+                          overriding this one, or overridden by this one),
+                          but that doesn't matter as far as the basic
+                          procsym is concerned.
+                        }
+                        srsym:=tprocdef(tprocsym(srsym).procdeflist[i]).procsym;
+                        srsymtable:=srsym.owner;
+                        { we need to know if a procedure references symbols
+                          in the static symtable, because then it can't be
+                          inlined from outside this unit }
+                        if assigned(current_procinfo) and
+                           (srsym.owner.symtabletype=staticsymtable) then
+                          include(current_procinfo.flags,pi_uses_static_symtable);
+                        addsymref(srsym);
+                        result:=true;
+                        exit;
+                      end;
+                  end;
+              end;
+            stackitem:=stackitem^.next;
+          end;
+        srsym:=nil;
+        srsymtable:=nil;
+        result:=false;
+      end;
+
 
     function search_class_member(pd : tobjectdef;const s : string):tsym;
     { searches n in symtable of pd and all anchestors }
       var
-        hashedid : THashedIDString;
+        hashedid   : THashedIDString;
         srsym      : tsym;
+        orgpd      : tobjectdef;
+        srsymtable : tsymtable;
       begin
         hashedid.id:=s;
+        orgpd:=pd;
         while assigned(pd) do
          begin
            srsym:=tsym(pd.symtable.FindWithHash(hashedid));
@@ -2030,9 +2103,15 @@ implementation
             end;
            pd:=pd.childof;
          end;
-        search_class_member:=nil;
+
+        { not found, now look for class helpers }
+        if is_objcclass(pd) then
+          search_class_helper(orgpd,s,result,srsymtable)
+        else
+          result:=nil;
       end;
 
+
     function search_macro(const s : string):tsym;
       var
         stackitem  : psymtablestackitem;

compiler/tokens.pas

@@ -250,6 +250,7 @@ type
     _EXPERIMENTAL,
     _FINALIZATION,
     _NOSTACKFRAME,
+    _OBJCCATEGORY,
     _OBJCPROTOCOL,
     _WEAKEXTERNAL,
     _DISPINTERFACE,
@@ -510,6 +511,7 @@ const
       (str:'EXPERIMENTAL'  ;special:false;keyword:m_all;op:NOTOKEN),
       (str:'FINALIZATION'  ;special:false;keyword:m_initfinal;op:NOTOKEN),
       (str:'NOSTACKFRAME'  ;special:false;keyword:m_none;op:NOTOKEN),
+      (str:'OBJCCATEGORY'  ;special:false;keyword:m_objectivec1;op:NOTOKEN), { Objective-C category }
       (str:'OBJCPROTOCOL'  ;special:false;keyword:m_objectivec1;op:NOTOKEN), { Objective-C protocol }
       (str:'WEAKEXTERNAL'  ;special:false;keyword:m_none;op:NOTOKEN),
       (str:'DISPINTERFACE' ;special:false;keyword:m_class;op:NOTOKEN),

compiler/utils/ppudump.pp

@@ -1390,7 +1390,8 @@ type
     oo_has_enumerator_movenext,
     oo_has_enumerator_current,
     oo_is_external,       { the class is externally implemented (objcclass, cppclass) }
-    oo_is_anonymous       { the class is only formally defined in this module (objcclass x = class; external;) }
+    oo_is_anonymous,      { the class is only formally defined in this module (objcclass x = class; external;) }
+    oo_is_classhelper     { objcclasses that represent categories, and Delpi-style class helpers, are marked like this }
   );
   tobjectoptions=set of tobjectoption;
   tsymopt=record
@@ -1418,7 +1419,8 @@ const
      (mask:oo_has_enumerator_movenext; str:'HasEnumeratorMoveNext'),
      (mask:oo_has_enumerator_current;  str:'HasEnumeratorCurrent'),
      (mask:oo_is_external;        str:'External'),
-     (mask:oo_is_anonymous;       str:'Anonymous'));
+     (mask:oo_is_anonymous;       str:'Anonymous'),
+     (mask:oo_is_classhelper;     str:'Class Helper/Category'));
 var
   symoptions : tobjectoptions;
   i      : longint;

tests/test/tobjc24.pp

@@ -0,0 +1,16 @@
+{ %fail }
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+
+{$modeswitch objectivec1}
+
+uses
+  uobjc24;
+
+var
+  a: ta;
+
+begin
+  { category is in implementation -> should not be visible here }
+  ta.implementationcategorymethod;
+end.

tests/test/tobjc25.pp

@@ -0,0 +1,122 @@
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+
+{$mode objfpc}
+{$modeswitch objectivec1}
+
+type
+  tbaseclass = objccategory(NSObject)
+    function tabaseproc(cp: longint): double; message 'tabaseproc:';
+    class function taclassproc: longint; message 'taclassproc';
+  end;
+
+  ta = objcclass(NSObject)
+    a: longint;
+    procedure taproc; message 'taproc';
+    function tabaseproc(cp: longint): double; message 'tabaseproc:'; //override; -- override doesn't work, the compiler doesn't treat the category as part of NSObject
+    class function taclassproc: longint; message 'taclassproc'; //override; -- idem
+  end;
+
+  ca = objccategory(ta)
+    procedure categorymethod; message 'categorymethod';
+    function tabaseproc(cp: longint): double; reintroduce;
+  end;
+
+  da = objccategory(ta)
+    procedure anothercategorymethod; message 'anothercategorymethod';
+    class function taclassproc: longint; reintroduce;
+  end;
+
+class function tbaseclass.taclassproc: longint;
+begin
+  writeln('tbaseclass.taclassproc');
+  result:=654321;
+end;
+
+function tbaseclass.tabaseproc(cp: longint): double;
+begin
+  writeln('tbaseclass.tabaseproc');
+  if (cp<>98765) then
+    halt(12);
+  result:=1234.875;
+end;
+
+procedure ta.taproc;
+begin
+  a:=0;
+  categorymethod;
+  if (a<>1) then
+    halt(1);
+  anothercategorymethod;
+  if (a<>2) then
+    halt(2);
+  if taclassproc<>123456 then
+    halt(5);
+end;
+
+function ta.tabaseproc(cp: longint): double;
+begin
+  { should be replaced/hidden by ca.tabaseproc }
+  halt(9);
+  result:=-1.0;
+end;
+
+class function ta.taclassproc: longint;
+begin
+  { should be replaced/hidden by da.taclassproc }
+  halt(3);
+  result:=0;
+end;
+
+procedure ca.categorymethod;
+begin
+  a:=1;
+  if tabaseproc(555) <> 1.0 then
+    halt(16);
+end;
+
+function ca.tabaseproc(cp: longint): double;
+begin
+  writeln('start ca.tabaseproc');
+  if (cp<>555) then
+    halt(13);
+  if inherited tabaseproc(98765)<>1234.875 then
+    halt(11);
+  writeln('end ca.tabaseproc');
+  result:=1.0;
+end;
+
+procedure da.anothercategorymethod;
+begin
+  a:=2;
+  if tabaseproc(555)<>1.0 then
+    halt(15);
+end;
+
+class function da.taclassproc: longint;
+begin
+  writeln('start da.taclassproc, calling inherited');
+  if inherited taclassproc<>654321 then
+    halt(4);
+  writeln('end da.taclassproc');
+  result:=123456;
+end;
+
+var
+  a: ta;
+begin
+  a:=ta(ta.alloc).init;
+  a.taproc;
+  a.a:=0;
+  a.categorymethod;
+  if (a.a<>1) then
+    halt(6);
+  a.anothercategorymethod;
+  if (a.a<>2) then
+    halt(7);
+  if a.taclassproc<>123456 then
+    halt(8);
+  if (a.tabaseproc(555)<>1.0) then
+    halt(14);
+  a.release;
+end.

tests/test/tobjc26.pp

@@ -0,0 +1,18 @@
+{ %fail }
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+
+{$modeswitch objectivec1}
+
+uses
+  uobjc26;
+
+var
+  a: ta;
+
+begin
+  a:=ta(ta.alloc).init;
+  // should not be visible
+  a.implementationcategorymethod;
+  a.release
+end.

tests/test/tobjc26a.pp

@@ -0,0 +1,16 @@
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+
+{$modeswitch objectivec1}
+
+uses
+  uobjc26;
+
+var
+  a: ta;
+
+begin
+  a:=ta(ta.alloc).init;
+  a.taproc;
+  a.release
+end.

tests/test/tobjc27a.pp

@@ -0,0 +1,26 @@
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+{ %recompile }
+
+{$modeswitch objectivec1}
+
+uses
+  uobjc27a,uobjc27b;
+
+var
+  a: ta;
+  c: tachild;
+
+begin
+  a:=ta(ta.alloc).init;
+  if a.da_categorymethod<>2 then
+    halt(1);
+  a.release;
+
+  c:=tachild(tachild.alloc).init;
+  if c.da_categorymethod<>2 then
+    halt(2);
+  if c.eachild_categorymethod<>3 then
+    halt(3);
+  c.release;
+end.

tests/test/tobjc27b.pp

@@ -0,0 +1,17 @@
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+{ %fail }
+
+{$modeswitch objectivec1}
+
+uses
+  uobjc27a;
+
+var
+  a: ta;
+
+begin
+  { da_category method is declared in uobjc27a, which is used in the
+    implementation of uobjc27b -> should not be visible here }
+  a.da_categorymethod;
+end.

tests/test/tobjc28.pp

@@ -0,0 +1,25 @@
+{ %target=darwin }
+{ %cpu=powerpc,powerpc64,i386,x86_64,arm }
+{ %fail }
+
+{$modeswitch objectivec1}
+
+type
+  ta = objcclass(NSObject)
+  end;
+
+  ca = objccategory(ta)
+    procedure categorymethod; message 'categorymethod';
+  end;
+
+procedure ca.categorymethod;
+begin
+end;
+
+var
+  a: NSObject;
+begin
+  a:=ta(ta.alloc).init;
+  { should fail because the category is for ta, not for nsobject }
+  a.categorymethod;
+end.

tests/test/uobjc24.pp

@@ -0,0 +1,22 @@
+{$modeswitch objectivec1}
+
+unit uobjc24;
+
+interface
+
+type
+  ta = objcclass(NSObject)
+  end;
+
+implementation
+
+type
+  ca = objccategory(ta)
+    procedure implementationcategorymethod;
+  end;
+
+procedure ca.implementationcategorymethod;
+begin
+end;
+
+end.

tests/test/uobjc26.pp

@@ -0,0 +1,33 @@
+{$modeswitch objectivec1}
+
+unit uobjc26;
+
+interface
+
+type
+  ta = objcclass(NSObject)
+    l: longint;
+    procedure taproc; message 'taproc';
+  end;
+
+implementation
+
+type
+  ca = objccategory(ta)
+    procedure implementationcategorymethod; message 'implementationcategorymethod';
+  end;
+
+procedure ca.implementationcategorymethod;
+begin
+  l:=1;
+end;
+
+procedure ta.taproc;
+begin
+  l:=0;
+  implementationcategorymethod;
+  if l<>1 then
+    halt(1);
+end;
+
+end.

tests/test/uobjc27a.pp

@@ -0,0 +1,27 @@
+{$mode objfpc}
+{$modeswitch objectivec1}
+
+unit uobjc27a;
+
+interface
+
+type
+  ta = objcclass(NSObject)
+  end;
+
+type
+  ca = objccategory(ta)
+    function ca_categorymethod: longint; message 'ca_categorymethod';
+  end;
+
+implementation
+
+uses
+  uobjc27b;
+
+function ca.ca_categorymethod: longint;
+begin
+  result:=da_categorymethod-1;
+end;
+
+end.

tests/test/uobjc27b.pp

@@ -0,0 +1,35 @@
+{$mode objfpc}
+{$modeswitch objectivec1}
+
+unit uobjc27b;
+
+interface
+
+uses uobjc27a;
+
+type
+  tachild = objcclass(ta)
+  end;
+
+type
+  eachild = objccategory(tachild)
+    function eachild_categorymethod: longint; message 'eachild_categorymethod';
+  end;
+
+  da = objccategory(ta)
+    function da_categorymethod: longint; message 'da_categorymethod';
+  end;
+
+implementation
+
+function eachild.eachild_categorymethod: longint;
+begin
+  result:=ca_categorymethod+2;
+end;
+
+function da.da_categorymethod: longint;
+begin
+  result:=2;
+end;
+
+end.