* give an error when calling a virtual constructor from another constructor

on the JVM target, because the generated code was invalid and I can't think
    of a generic way to solve it (see added comments in njvmcal.pas)

git-svn-id: branches/jvmbackend@19055 -

compiler/jvm/njvmcal.pas

@@ -51,6 +51,7 @@ interface
          function dispatch_procvar: tnode;
          procedure remove_hidden_paras;
         public
+         function pass_typecheck: tnode; override;
          function pass_1: tnode; override;
        end;
 
@@ -58,7 +59,7 @@ interface
 implementation
 
     uses
-      verbose,globtype,constexp,cutils,
+      verbose,globals,globtype,constexp,cutils,
       symconst,symtable,symsym,defutil,
       cgutils,tgobj,procinfo,htypechk,
       cpubase,aasmdata,aasmcpu,
@@ -454,6 +455,37 @@ implementation
     end;
 
 
+  function tjvmcallnode.pass_typecheck: tnode;
+    begin
+      result:=inherited pass_typecheck;
+      if assigned(result) or
+         codegenerror then
+        exit;
+      { unfortunately, we cannot handle a call to a virtual constructor for
+        the current instance from inside another constructor. The reason is
+        that these must be called via reflection, but before an instance has
+        been fully initialized (which can only be done by calling either an
+        inherited constructor or another constructor of this class) you can't
+        perform reflection.
+
+        Replacing virtual constructors with plain virtual methods that are
+        called after the instance has been initialized causes problems if they
+        in turn call plain constructors from inside the JDK (you cannot call
+        constructors anymore once the instance has been constructed). It also
+        causes problems regarding which other constructor to call then instead
+        before to initialize the instance (we could add dummy constructors for
+        that purpose to Pascal classes, but that scheme breaks when a class
+        inherits from a JDK class other than JLObject).
+      }
+      if (current_procinfo.procdef.proctypeoption=potype_constructor) and
+         not(cnf_inherited in callnodeflags) and
+         (procdefinition.proctypeoption=potype_constructor) and
+         (po_virtualmethod in procdefinition.procoptions) and
+         (cnf_member_call in callnodeflags) then
+        CGMessage(parser_e_jvm_invalid_virtual_constructor_call);
+    end;
+
+
   function tjvmcallnode.dispatch_procvar: tnode;
     var
       pdclass: tobjectdef;

compiler/msg/errore.msg

@@ -379,7 +379,7 @@ scanner_w_directive_ignored_on_target=02089_W_Directive "$1" is ignored for the
 #
 # Parser
 #
-# 03319 is the last used one
+# 03320 is the last used one
 #
 % \section{Parser messages}
 % This section lists all parser messages. The parser takes care of the
@@ -1426,6 +1426,11 @@ parser_d_internal_parser_string=03318_D_Parsing internally generated code: $1
 % with debugging errors in them.
 parser_e_feature_unsupported_for_vm=03319_E_This language feature is not supported on managed VM targets
 % Certain language features are not supported on targets that are managed virtual machines.
+parser_e_jvm_invalid_virtual_constructor_call=03320_E_Calling a virtual constructor for the current instance inside another constructor is not possible on the JVM target
+% The JVM does not natively support virtual constructor. Unforunately, we are not aware of a way to
+% emulate them in a way that makes it possible to support calling virtual constructors
+% for the current instance inside another constructor.
+%
 % \end{description}
 # Type Checking
 #

compiler/msgidx.inc

@@ -412,6 +412,7 @@ const
   parser_e_java_no_inherited_constructor=03317;
   parser_d_internal_parser_string=03318;
   parser_e_feature_unsupported_for_vm=03319;
+  parser_e_jvm_invalid_virtual_constructor_call=03320;
   type_e_mismatch=04000;
   type_e_incompatible_types=04001;
   type_e_not_equal_types=04002;
@@ -913,9 +914,9 @@ const
   option_info=11024;
   option_help_pages=11025;
 
-  MsgTxtSize = 62122;
+  MsgTxtSize = 62246;
 
   MsgIdxMax : array[1..20] of longint=(
-    26,90,320,107,87,54,111,23,202,63,
+    26,90,321,107,87,54,111,23,202,63,
     49,20,1,1,1,1,1,1,1,1
   );