[Ada] Resolution of parameterless calls that return arrays

[Arnaud Charlet <charlet at adacore dot com>]

This patch handles properly additional constructs of the form F.all (I), where
F is an access_to_function that can be called without parameters, and  that
returns an array type.

Compiling err.adb must yield:

err.adb:23:09: too many arguments in call to "A"
err.adb:24:09: too many arguments in call

---
procedure Err is
   function F return String is
   begin      
      return "ABCD";
   end F;
   
   type Acc_F is access function return String;
   
   function A return Acc_F Is
   begin
      return F'Access;
   end A;

   function AA (I : Integer) return Acc_F Is
   begin
      return F'Access;
   end AA;

   B : Integer := 1;
   C : Character;

begin
   C := A (B);           -- (1) too many arguments in call
   C := AA(1) (B);       -- (3) too many arguments in call
end Err;
---

Executing essai.adb must yield:

'A'
'B'
'C'

---
with Text_IO; use Text_IO;
procedure Essai is
   function F return String is
   begin      
      return "ABCD";
   end F;
   
   type Acc_F is access function return String;
   
   function A return Acc_F Is
   begin
      return F'Access;
   end A;

   function AA (I : Integer) return Acc_F Is
   begin
      return F'Access;
   end AA;

   B : Integer := 1;
   C : Character;

begin
   C := A.all (B);
   Put_Line (Character'image (C)); B := B+1;
   C := AA(1).all (B);
   Put_Line (Character'image (C)); B := B+1;
   C := F(B);
   Put_Line (Character'image (C)); B := B+1;
end Essai;

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

2013-09-10  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch3.adb (Access_Subprogram_Declaration): Check whether the
	designated type can appear in a parameterless call.
	* sem_ch4.adb (Analyze_Call): Do not insert an explicit dereference
	in the case of an indirect call through an access function that
	returns an array type.
	(Analyze_One_Call): Handle properly legal parameterless calls
	whose result is indexed, in constructs of the for F.all (I)
	* sem_ch6.ads (May_Need_Actuals): Make public, for use on access
	to subprogram types.
	* sem_res.adb (Resolve_Call): If the call is indirect, there is
	no entity to set on the name in the call.

Attachment: difs
Description: Text document