[Ada] Missing error on hidden state in instantiation

This patch modifies the analysis of package contracts to split processing
which is specific to package instantiations on its own. As a result, the
lack of indicator Part_Of can now be properly assessed.

------------
-- Source --
------------

--  gen_pack.ads

generic
package Gen_Pack is
   Pack_Var : Integer := 1;
end Gen_Pack;

--  gen_wrap.ads

with Gen_Pack;

generic
package Gen_Wrap is
   Wrap_Var : Integer := 1;

   package Inst is new Gen_Pack;
end Gen_Wrap;

--  pack.ads

with Gen_Pack;
with Gen_Wrap;

package Pack
  with SPARK_Mode     => On,
       Abstract_State => State
is
   procedure Force_Body;

private
   package OK_Inst_1 is new Gen_Pack                                 --  OK
     with Part_Of => State;                                          --  OK

   package OK_Inst_2 is new Gen_Pack;                                --  OK
   pragma Part_Of (State);                                           --  OK

   package OK_Inst_3 is new Gen_Wrap                                 --  OK
     with Part_Of => State;                                          --  OK

   package OK_Inst_4 is new Gen_Wrap;                                --  OK
   pragma Part_Of (State);

   package Error_Inst_1 is new Gen_Pack;                             --  Error
   package Error_Inst_2 is new Gen_Wrap;                             --  Error
end Pack;

--  pack.adb

package body Pack
  with SPARK_Mode    => On,
       Refined_State =>
         (State => (OK_Inst_1.Pack_Var, OK_Inst_2.Pack_Var,
                    OK_Inst_3.Wrap_Var, OK_Inst_3.Inst.Pack_Var,
                    OK_Inst_4.Wrap_Var, OK_Inst_4.Inst.Pack_Var))
is
   procedure Force_Body is null;
end Pack;

----------------------------
-- Compilation and output --
----------------------------

$ gcc -c pack.adb
pack.ads:23:12: indicator Part_Of is required in this context (SPARK RM
  7.2.6(2))
pack.ads:23:12: "Error_Inst_1" is declared in the private part of package
  "Pack"
pack.ads:24:12: indicator Part_Of is required in this context (SPARK RM
  7.2.6(2))
pack.ads:24:12: "Error_Inst_2" is declared in the private part of package
  "Pack"

2018-07-16  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* contracts.adb (Analyze_Contracts): Add specialized processing for
	package instantiation contracts.
	(Analyze_Package_Contract): Remove the verification of a missing
	Part_Of indicator.
	(Analyze_Package_Instantiation_Contract): New routine.
	* contracts.ads (Analyze_Package_Contract): Update the comment on
	usage.
	* sem_prag.adb (Check_Missing_Part_Of): Ensure that the entity of the
	instance is being examined when trying to determine whether a package
	instantiation needs a Part_Of indicator.

From-SVN: r262731

1 files changed, 8 insertions, 1 deletions

diff --git a/gcc/ada/contracts.ads b/gcc/ada/contracts.ads
index 4a0997f..46f52d1 100644
--- a/gcc/ada/contracts.ads
+++ b/gcc/ada/contracts.ads
@@ -35,6 +35,7 @@ package Contracts is
    --  [generic] package, package body, protected unit, [generic] subprogram,
    --  subprogram body, variable or task unit denoted by Id. The following are
    --  valid pragmas:
+   --
    --    Abstract_State
    --    Async_Readers
    --    Async_Writers
@@ -66,6 +67,7 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of entry or
    --  subprogram body Body_Id as if they appeared at the end of a declarative
    --  region. Pragmas in question are:
+   --
    --    Contract_Cases   (stand alone subprogram body)
    --    Depends          (stand alone subprogram body)
    --    Global           (stand alone subprogram body)
@@ -82,6 +84,7 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of entry or
    --  subprogram Subp_Id as if they appeared at the end of a declarative
    --  region. The pragmas in question are:
+   --
    --    Contract_Cases
    --    Depends
    --    Global
@@ -98,6 +101,7 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of object Obj_Id as
    --  if they appeared at the end of the declarative region. The pragmas to be
    --  considered are:
+   --
    --    Async_Readers
    --    Async_Writers
    --    Depends           (single concurrent object)
@@ -115,6 +119,7 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of package body
    --  Body_Id as if they appeared at the end of a declarative region. The
    --  pragmas that are considered are:
+   --
    --    Refined_State
    --
    --  Freeze_Id is the entity of a [generic] package body or a [generic]
@@ -124,9 +129,9 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of package Pack_Id
    --  as if they appeared at the end of a declarative region. The pragmas
    --  that are considered are:
+   --
    --    Initial_Condition
    --    Initializes
-   --    Part_Of
 
    procedure Analyze_Protected_Contract (Prot_Id : Entity_Id);
    --  Analyze all delayed pragmas chained on the contract of protected unit
@@ -137,6 +142,7 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of subprogram body
    --  stub Stub_Id as if they appeared at the end of a declarative region. The
    --  pragmas in question are:
+   --
    --    Contract_Cases
    --    Depends
    --    Global
@@ -151,6 +157,7 @@ package Contracts is
    --  Analyze all delayed pragmas chained on the contract of task unit Task_Id
    --  as if they appeared at the end of a declarative region. The pragmas in
    --  question are:
+   --
    --    Depends
    --    Global