[Ada] Wrong initialization of extended aggregates of CPP types

The code generated by the compiler to initialize extended aggregates
of imported C++ types leaves objects partially initialized. As a
result, dispatching calls using these objects have unexpected
results. The following test must execute fine and print "OK".

class Base {
  public:
  int My_V;
  Base ();
  virtual void Primitive ();
};

Base::Base ()  {
}

void Base::Primitive () {
}

with Interfaces.C; use Interfaces.C;
package file_cpp is
   package Class_Base is
      type Base is tagged limited record
         My_V : aliased int;
      end record;
      pragma Import (CPP, Base);

      function New_Base return Base;
      pragma CPP_Constructor (New_Base, "_ZN4BaseC1Ev");

      procedure Primitive (this : access Base);
      pragma Import (CPP, Primitive, "_ZN4Base9PrimitiveEv");
   end;
   use Class_Base;
end file_cpp;

with file_cpp; use file_cpp;
package Deriv is
   use file_cpp.Class_Base;
   type My_Class is new Base with null record;
   type My_Class_Access is access all My_Class'Class;

   overriding
   procedure Primitive (this : access My_Class);
end Deriv;

with Text_IO; use Text_IO;
package body Deriv is
   procedure Primitive (this : access My_Class) is
   begin
      Put_Line ("OK");
   end Primitive;
end Deriv;

with file_cpp; use file_cpp;
with Deriv; use Deriv;
procedure Main is
   use file_cpp.Class_Base;
   V : My_Class_Access :=
         new My_Class'(New_Base with others => <>);  --  Test
begin
   Primitive (V);                                     -- Test
end Main;

project Default is
   for Languages use ("Ada", "C++");
   for Main use ("main.adb");

   package Ide is
      for Vcs_Kind use "CVS";
      for Compiler_Command ("c") use "gcc";
   end Ide;

   package Compiler is
      for Default_Switches ("ada") use ("-O2", "-gnat05");
   end Compiler;
end Default;

Command: gprbuild -q -P default.gpr; ./main
Output:  OK

Tested on x86_64-pc-linux-gnu, committed on trunk

2010-08-10  Javier Miranda  <miranda@adacore.com>

	* sem_aggr.adb (Resolve_Extension_Aggregate): Warn on the use of C++
	constructors that leave the object partially initialized.
	* exp_atag.ads, exp_atags.adb (Build_Inherit_CPP_Prims): New subprogram
	that copies from parent of Typ the dispatch table slots of inherited
	C++ primitives. It handles primary and secondary dispatch tables.
	* einfo.adb (Related_Type): Moved from Node26 to Node27. Required to
	use this attribute with E_Variable entities.
	(Set_Is_Tag): Relax assertion to allow its use with variables that
	store tags.
	(Set_Related_Type): Relax assertion to allow its use with variables
	that store the tag of a C++ class.
	(Write_26_Field_Name): Remove Related_Type.
	(Write_27_Field_Name): Add Related_Type.
	* einfo.ads (Related_Type): Moved from Node26 to Node27. Available also
	with E_Variable entities.
	* sem_prag.adb (CPP_Constructor): Warn on duplicated occurrence of this
	pragma.
	* sem_util.adb (Search_Tag): Add missing support for CPP types.
	(Enclosing_CPP_Parent): New subprogram.
	(Has_Suffix): New subprogram.
	* sem_util.ads (Enclosing_CPP_Parent): New subprogram that returns the
	closest ancestor of a type that is a C++ type.
	(Has_Suffix): New subprogram. Used in assertions to check the suffix of
	internal entities.
	* sem_attr.adb (Analyze_Access_Attribute): Check wrong use of current
	instance in derivations of C++ types.
	* exp_tss.adb (CPP_Init_Proc): New subprogram.
	(Is_CPP_Init_Proc): New subprogram.
	(Set_TSS): Handle new C++ init routines.
	* exp_tss.ads (TSS_CPP_Init): New TSS name. For initialization of C++
	dispatch tables.
	(CPP_Init_Proc): New subprogram.
	(Is_CPP_Init_Proc): New subprogram.
	* exp_disp.adb (CPP_Num_Prims): New subprogram.
	(Has_CPP_Constructors): New subprogram.
	(Make_Secondary_DT, Make_DT): For derivations of CPP types, do not
	initialize slots located in the C++ part of the dispatch table.
	(Make_Tags): For CPP types declare variables used by the IP routine to
	store the C++ tag values after the first invocation of the C++
	constructor.
	(Build_CPP_Init_DT): New subprogram.
	(Set_CPP_Constructors): New implementation that builds an IP for each
	CPP constructor. These IP are wrappers of the C++ constructors that,
	after the first invocation of the constructor, read the C++ tags from
	the object and save them locally. These copies of the C++ tags are used
	by the IC routines to initialize tables of Ada derivations of CPP types.
	(Write_DT): Indicate what primitives are imported from C++
	* exp_disp.ads (CPP_Num_Prims): New subprogram.
	(Has_CPP_Constructors): New subprogram.
	* exp_aggr.adb (Build_Record_Aggr_Code): For derivations of C++ types
	invoke the IC routine to inherit the slots of the parents.
	* sem_ch13.adb (Analyze_Freeze_Entity): Add new warnings on CPP types.
	* exp_ch3.adb (Is_Variable_Size_Array): New subprogram.
	(Is_Variable_Size_Record): Factorize code calling
	Is_Variable_Size_Array.
	(Build_CPP_Init_Procedure): New subprogram that builds the tree
	corresponding to the procedure that initializes the C++ part of the
	dispatch table of an Ada tagged type that is a derivation of a CPP type.
	(Build_Init_Procedure): Adding documentation plus code reorganization to
	leave more clear the construction of the IP with C++ types.
	(Expand_Freeze_Record_Type): Delay call to Set_CPP_Constructors because
	it cannot be called after Make_Tags has been invoked.
	(Inherit_CPP_Tag): Removed.
	(Init_Secondary_Tags): For derivations of CPP types, warn on tags
	located at variable offset.
	* freeze.ads: Minor reformating.
	* sem_ch8.adb (Write_Scopes): Add pragma export. Required to have it
	available in gdb.
	* gcc-interface/Make-lang.in: Update dependencies.

[Ada] Wrong initialization of extended aggregates of CPP types

Commit Message

Patch