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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- L I B . X R E F . S P A R K _ S P E C I F I C --
-- --
-- B o d y --
-- --
-- Copyright (C) 2011-2016, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- http://www.gnu.org/licenses for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Einfo; use Einfo;
with Nmake; use Nmake;
with SPARK_Xrefs; use SPARK_Xrefs;
with GNAT.HTable;
separate (Lib.Xref)
package body SPARK_Specific is
---------------------
-- Local Constants --
---------------------
-- Table of SPARK_Entities, True for each entity kind used in SPARK
SPARK_Entities : constant array (Entity_Kind) of Boolean :=
(E_Constant => True,
E_Entry => True,
E_Function => True,
E_In_Out_Parameter => True,
E_In_Parameter => True,
E_Loop_Parameter => True,
E_Operator => True,
E_Out_Parameter => True,
E_Procedure => True,
E_Variable => True,
others => False);
-- True for each reference type used in SPARK
SPARK_References : constant array (Character) of Boolean :=
('m' => True,
'r' => True,
's' => True,
others => False);
type Entity_Hashed_Range is range 0 .. 255;
-- Size of hash table headers
---------------------
-- Local Variables --
---------------------
Heap : Entity_Id := Empty;
-- A special entity which denotes the heap object
package Drefs is new Table.Table (
Table_Component_Type => Xref_Entry,
Table_Index_Type => Xref_Entry_Number,
Table_Low_Bound => 1,
Table_Initial => Alloc.Drefs_Initial,
Table_Increment => Alloc.Drefs_Increment,
Table_Name => "Drefs");
-- Table of cross-references for reads and writes through explicit
-- dereferences, that are output as reads/writes to the special variable
-- "Heap". These references are added to the regular references when
-- computing SPARK cross-references.
-----------------------
-- Local Subprograms --
-----------------------
procedure Add_SPARK_File (Uspec, Ubody : Unit_Number_Type; Dspec : Nat);
-- Add file and corresponding scopes for unit to the tables
-- SPARK_File_Table and SPARK_Scope_Table. When two units are present
-- for the same compilation unit, as it happens for library-level
-- instantiations of generics, then Ubody is the number of the body
-- unit; otherwise it is No_Unit.
procedure Add_SPARK_Xrefs;
-- Filter table Xrefs to add all references used in SPARK to the table
-- SPARK_Xref_Table.
function Entity_Hash (E : Entity_Id) return Entity_Hashed_Range;
-- Hash function for hash table
--------------------
-- Add_SPARK_File --
--------------------
procedure Add_SPARK_File (Uspec, Ubody : Unit_Number_Type; Dspec : Nat) is
File : constant Source_File_Index := Source_Index (Uspec);
From : constant Scope_Index := SPARK_Scope_Table.Last + 1;
Scope_Id : Pos := 1;
procedure Add_SPARK_Scope (N : Node_Id);
-- Add scope N to the table SPARK_Scope_Table
procedure Detect_And_Add_SPARK_Scope (N : Node_Id);
-- Call Add_SPARK_Scope on scopes
---------------------
-- Add_SPARK_Scope --
---------------------
procedure Add_SPARK_Scope (N : Node_Id) is
E : constant Entity_Id := Defining_Entity (N);
Loc : constant Source_Ptr := Sloc (E);
-- The character describing the kind of scope is chosen to be the
-- same as the one describing the corresponding entity in cross
-- references, see Xref_Entity_Letters in lib-xrefs.ads
Typ : Character;
begin
-- Ignore scopes without a proper location
if Sloc (N) = No_Location then
return;
end if;
case Ekind (E) is
when E_Entry
| E_Entry_Family
| E_Generic_Function
| E_Generic_Package
| E_Generic_Procedure
| E_Package
| E_Protected_Type
| E_Task_Type
=>
Typ := Xref_Entity_Letters (Ekind (E));
when E_Function
| E_Procedure
=>
-- In SPARK we need to distinguish protected functions and
-- procedures from ordinary subprograms, but there are no
-- special Xref letters for them. Since this distiction is
-- only needed to detect protected calls, we pretend that
-- such calls are entry calls.
if Ekind (Scope (E)) = E_Protected_Type then
Typ := Xref_Entity_Letters (E_Entry);
else
Typ := Xref_Entity_Letters (Ekind (E));
end if;
when E_Package_Body
| E_Protected_Body
| E_Subprogram_Body
| E_Task_Body
=>
Typ := Xref_Entity_Letters (Ekind (Unique_Entity (E)));
when E_Void =>
-- Compilation of prj-attr.adb with -gnatn creates a node with
-- entity E_Void for the package defined at a-charac.ads16:13.
-- ??? TBD
return;
when others =>
raise Program_Error;
end case;
-- File_Num and Scope_Num are filled later. From_Xref and To_Xref
-- are filled even later, but are initialized to represent an empty
-- range.
SPARK_Scope_Table.Append
((Scope_Name => new String'(Unique_Name (E)),
File_Num => Dspec,
Scope_Num => Scope_Id,
Spec_File_Num => 0,
Spec_Scope_Num => 0,
Line => Nat (Get_Logical_Line_Number (Loc)),
Stype => Typ,
Col => Nat (Get_Column_Number (Loc)),
From_Xref => 1,
To_Xref => 0,
Scope_Entity => E));
Scope_Id := Scope_Id + 1;
end Add_SPARK_Scope;
--------------------------------
-- Detect_And_Add_SPARK_Scope --
--------------------------------
procedure Detect_And_Add_SPARK_Scope (N : Node_Id) is
begin
-- Entries
if Nkind_In (N, N_Entry_Body, N_Entry_Declaration)
-- Packages
or else Nkind_In (N, N_Package_Body,
N_Package_Body_Stub,
N_Package_Declaration)
-- Protected units
or else Nkind_In (N, N_Protected_Body,
N_Protected_Body_Stub,
N_Protected_Type_Declaration)
-- Subprograms
or else Nkind_In (N, N_Subprogram_Body,
N_Subprogram_Body_Stub,
N_Subprogram_Declaration)
-- Task units
or else Nkind_In (N, N_Task_Body,
N_Task_Body_Stub,
N_Task_Type_Declaration)
then
Add_SPARK_Scope (N);
end if;
end Detect_And_Add_SPARK_Scope;
procedure Traverse_Scopes is new
Traverse_Compilation_Unit (Detect_And_Add_SPARK_Scope);
-- Local variables
File_Name : String_Ptr;
Unit_File_Name : String_Ptr;
-- Start of processing for Add_SPARK_File
begin
-- Source file could be inexistant as a result of an error, if option
-- gnatQ is used.
if File = No_Source_File then
return;
end if;
-- Subunits are traversed as part of the top-level unit to which they
-- belong.
if Nkind (Unit (Cunit (Uspec))) = N_Subunit then
return;
end if;
Traverse_Scopes (CU => Cunit (Uspec), Inside_Stubs => True);
-- When two units are present for the same compilation unit, as it
-- happens for library-level instantiations of generics, then add all
-- scopes to the same SPARK file.
if Ubody /= No_Unit then
Traverse_Scopes (CU => Cunit (Ubody), Inside_Stubs => True);
end if;
-- Make entry for new file in file table
Get_Name_String (Reference_Name (File));
File_Name := new String'(Name_Buffer (1 .. Name_Len));
-- For subunits, also retrieve the file name of the unit. Only do so if
-- unit has an associated compilation unit.
if Present (Cunit (Unit (File)))
and then Nkind (Unit (Cunit (Unit (File)))) = N_Subunit
then
Get_Name_String (Reference_Name (Main_Source_File));
Unit_File_Name := new String'(Name_Buffer (1 .. Name_Len));
else
Unit_File_Name := null;
end if;
SPARK_File_Table.Append (
(File_Name => File_Name,
Unit_File_Name => Unit_File_Name,
File_Num => Dspec,
From_Scope => From,
To_Scope => SPARK_Scope_Table.Last));
end Add_SPARK_File;
---------------------
-- Add_SPARK_Xrefs --
---------------------
procedure Add_SPARK_Xrefs is
function Entity_Of_Scope (S : Scope_Index) return Entity_Id;
-- Return the entity which maps to the input scope index
function Get_Entity_Type (E : Entity_Id) return Character;
-- Return a character representing the type of entity
function Get_Scope_Num (N : Entity_Id) return Nat;
-- Return the scope number associated to entity N
function Is_Constant_Object_Without_Variable_Input
(E : Entity_Id) return Boolean;
-- Return True if E is known to have no variable input, as defined in
-- SPARK RM.
function Is_Future_Scope_Entity
(E : Entity_Id;
S : Scope_Index) return Boolean;
-- Check whether entity E is in SPARK_Scope_Table at index S or higher
function Is_SPARK_Reference
(E : Entity_Id;
Typ : Character) return Boolean;
-- Return whether entity reference E meets SPARK requirements. Typ is
-- the reference type.
function Is_SPARK_Scope (E : Entity_Id) return Boolean;
-- Return whether the entity or reference scope meets requirements for
-- being a SPARK scope.
function Lt (Op1 : Natural; Op2 : Natural) return Boolean;
-- Comparison function for Sort call
procedure Move (From : Natural; To : Natural);
-- Move procedure for Sort call
procedure Set_Scope_Num (N : Entity_Id; Num : Nat);
-- Associate entity N to scope number Num
procedure Update_Scope_Range
(S : Scope_Index;
From : Xref_Index;
To : Xref_Index);
-- Update the scope which maps to S with the new range From .. To
package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
No_Scope : constant Nat := 0;
-- Initial scope counter
type Scope_Rec is record
Num : Nat;
Entity : Entity_Id;
end record;
-- Type used to relate an entity and a scope number
package Scopes is new GNAT.HTable.Simple_HTable
(Header_Num => Entity_Hashed_Range,
Element => Scope_Rec,
No_Element => (Num => No_Scope, Entity => Empty),
Key => Entity_Id,
Hash => Entity_Hash,
Equal => "=");
-- Package used to build a correspondence between entities and scope
-- numbers used in SPARK cross references.
Nrefs : Nat := Xrefs.Last;
-- Number of references in table. This value may get reset (reduced)
-- when we eliminate duplicate reference entries as well as references
-- not suitable for local cross-references.
Nrefs_Add : constant Nat := Drefs.Last;
-- Number of additional references which correspond to dereferences in
-- the source code.
Rnums : array (0 .. Nrefs + Nrefs_Add) of Nat;
-- This array contains numbers of references in the Xrefs table. This
-- list is sorted in output order. The extra 0'th entry is convenient
-- for the call to sort. When we sort the table, we move the indices in
-- Rnums around, but we do not move the original table entries.
---------------------
-- Entity_Of_Scope --
---------------------
function Entity_Of_Scope (S : Scope_Index) return Entity_Id is
begin
return SPARK_Scope_Table.Table (S).Scope_Entity;
end Entity_Of_Scope;
---------------------
-- Get_Entity_Type --
---------------------
function Get_Entity_Type (E : Entity_Id) return Character is
begin
case Ekind (E) is
when E_Out_Parameter => return '<';
when E_In_Out_Parameter => return '=';
when E_In_Parameter => return '>';
when others => return '*';
end case;
end Get_Entity_Type;
-------------------
-- Get_Scope_Num --
-------------------
function Get_Scope_Num (N : Entity_Id) return Nat is
begin
return Scopes.Get (N).Num;
end Get_Scope_Num;
-----------------------------------------------
-- Is_Constant_Object_Without_Variable_Input --
-----------------------------------------------
function Is_Constant_Object_Without_Variable_Input
(E : Entity_Id) return Boolean
is
Result : Boolean;
begin
case Ekind (E) is
-- A constant is known to have no variable input if its
-- initializing expression is static (a value which is
-- compile-time-known is not guaranteed to have no variable input
-- as defined in the SPARK RM). Otherwise, the constant may or not
-- have variable input.
when E_Constant =>
declare
Decl : Node_Id;
begin
if Present (Full_View (E)) then
Decl := Parent (Full_View (E));
else
Decl := Parent (E);
end if;
if Is_Imported (E) then
Result := False;
else
pragma Assert (Present (Expression (Decl)));
Result := Is_Static_Expression (Expression (Decl));
end if;
end;
when E_In_Parameter
| E_Loop_Parameter
=>
Result := True;
when others =>
Result := False;
end case;
return Result;
end Is_Constant_Object_Without_Variable_Input;
----------------------------
-- Is_Future_Scope_Entity --
----------------------------
function Is_Future_Scope_Entity
(E : Entity_Id;
S : Scope_Index) return Boolean
is
function Is_Past_Scope_Entity return Boolean;
-- Check whether entity E is in SPARK_Scope_Table at index strictly
-- lower than S.
--------------------------
-- Is_Past_Scope_Entity --
--------------------------
function Is_Past_Scope_Entity return Boolean is
begin
for Index in SPARK_Scope_Table.First .. S - 1 loop
if SPARK_Scope_Table.Table (Index).Scope_Entity = E then
return True;
end if;
end loop;
return False;
end Is_Past_Scope_Entity;
-- Start of processing for Is_Future_Scope_Entity
begin
for Index in S .. SPARK_Scope_Table.Last loop
if SPARK_Scope_Table.Table (Index).Scope_Entity = E then
return True;
end if;
end loop;
-- If this assertion fails, this means that the scope which we are
-- looking for has been treated already, which reveals a problem in
-- the order of cross-references.
pragma Assert (not Is_Past_Scope_Entity);
return False;
end Is_Future_Scope_Entity;
------------------------
-- Is_SPARK_Reference --
------------------------
function Is_SPARK_Reference
(E : Entity_Id;
Typ : Character) return Boolean
is
begin
-- The only references of interest on callable entities are calls. On
-- uncallable entities, the only references of interest are reads and
-- writes.
if Ekind (E) in Overloadable_Kind then
return Typ = 's';
-- In all other cases, result is true for reference/modify cases,
-- and false for all other cases.
else
return Typ = 'r' or else Typ = 'm';
end if;
end Is_SPARK_Reference;
--------------------
-- Is_SPARK_Scope --
--------------------
function Is_SPARK_Scope (E : Entity_Id) return Boolean is
begin
return Present (E)
and then not Is_Generic_Unit (E)
and then Renamed_Entity (E) = Empty
and then Get_Scope_Num (E) /= No_Scope;
end Is_SPARK_Scope;
--------
-- Lt --
--------
function Lt (Op1 : Natural; Op2 : Natural) return Boolean is
T1 : constant Xref_Entry := Xrefs.Table (Rnums (Nat (Op1)));
T2 : constant Xref_Entry := Xrefs.Table (Rnums (Nat (Op2)));
begin
-- First test: if entity is in different unit, sort by unit. Note:
-- that we use Ent_Scope_File rather than Eun, as Eun may refer to
-- the file where the generic scope is defined, which may differ from
-- the file where the enclosing scope is defined. It is the latter
-- which matters for a correct order here.
if T1.Ent_Scope_File /= T2.Ent_Scope_File then
return Dependency_Num (T1.Ent_Scope_File) <
Dependency_Num (T2.Ent_Scope_File);
-- Second test: within same unit, sort by location of the scope of
-- the entity definition.
elsif Get_Scope_Num (T1.Key.Ent_Scope) /=
Get_Scope_Num (T2.Key.Ent_Scope)
then
return Get_Scope_Num (T1.Key.Ent_Scope) <
Get_Scope_Num (T2.Key.Ent_Scope);
-- Third test: within same unit and scope, sort by location of
-- entity definition.
elsif T1.Def /= T2.Def then
return T1.Def < T2.Def;
else
-- Both entities must be equal at this point
pragma Assert (T1.Key.Ent = T2.Key.Ent);
pragma Assert (T1.Key.Ent_Scope = T2.Key.Ent_Scope);
pragma Assert (T1.Ent_Scope_File = T2.Ent_Scope_File);
-- Fourth test: if reference is in same unit as entity definition,
-- sort first.
if T1.Key.Lun /= T2.Key.Lun
and then T1.Ent_Scope_File = T1.Key.Lun
then
return True;
elsif T1.Key.Lun /= T2.Key.Lun
and then T2.Ent_Scope_File = T2.Key.Lun
then
return False;
-- Fifth test: if reference is in same unit and same scope as
-- entity definition, sort first.
elsif T1.Ent_Scope_File = T1.Key.Lun
and then T1.Key.Ref_Scope /= T2.Key.Ref_Scope
and then T1.Key.Ent_Scope = T1.Key.Ref_Scope
then
return True;
elsif T2.Ent_Scope_File = T2.Key.Lun
and then T1.Key.Ref_Scope /= T2.Key.Ref_Scope
and then T2.Key.Ent_Scope = T2.Key.Ref_Scope
then
return False;
-- Sixth test: for same entity, sort by reference location unit
elsif T1.Key.Lun /= T2.Key.Lun then
return Dependency_Num (T1.Key.Lun) <
Dependency_Num (T2.Key.Lun);
-- Seventh test: for same entity, sort by reference location scope
elsif Get_Scope_Num (T1.Key.Ref_Scope) /=
Get_Scope_Num (T2.Key.Ref_Scope)
then
return Get_Scope_Num (T1.Key.Ref_Scope) <
Get_Scope_Num (T2.Key.Ref_Scope);
-- Eighth test: order of location within referencing unit
elsif T1.Key.Loc /= T2.Key.Loc then
return T1.Key.Loc < T2.Key.Loc;
-- Finally, for two locations at the same address prefer the one
-- that does NOT have the type 'r', so that a modification or
-- extension takes preference, when there are more than one
-- reference at the same location. As a result, in the case of
-- entities that are in-out actuals, the read reference follows
-- the modify reference.
else
return T2.Key.Typ = 'r';
end if;
end if;
end Lt;
----------
-- Move --
----------
procedure Move (From : Natural; To : Natural) is
begin
Rnums (Nat (To)) := Rnums (Nat (From));
end Move;
-------------------
-- Set_Scope_Num --
-------------------
procedure Set_Scope_Num (N : Entity_Id; Num : Nat) is
begin
Scopes.Set (K => N, E => Scope_Rec'(Num => Num, Entity => N));
end Set_Scope_Num;
------------------------
-- Update_Scope_Range --
------------------------
procedure Update_Scope_Range
(S : Scope_Index;
From : Xref_Index;
To : Xref_Index)
is
begin
SPARK_Scope_Table.Table (S).From_Xref := From;
SPARK_Scope_Table.Table (S).To_Xref := To;
end Update_Scope_Range;
-- Local variables
Col : Nat;
From_Index : Xref_Index;
Line : Nat;
Prev_Loc : Source_Ptr;
Prev_Typ : Character;
Ref_Count : Nat;
Ref_Id : Entity_Id;
Ref_Name : String_Ptr;
Scope_Id : Scope_Index;
-- Start of processing for Add_SPARK_Xrefs
begin
for Index in SPARK_Scope_Table.First .. SPARK_Scope_Table.Last loop
declare
S : SPARK_Scope_Record renames SPARK_Scope_Table.Table (Index);
begin
Set_Scope_Num (S.Scope_Entity, S.Scope_Num);
end;
end loop;
declare
Drefs_Table : Drefs.Table_Type
renames Drefs.Table (Drefs.First .. Drefs.Last);
begin
Xrefs.Append_All (Xrefs.Table_Type (Drefs_Table));
Nrefs := Nrefs + Drefs_Table'Length;
end;
-- Capture the definition Sloc values. As in the case of normal cross
-- references, we have to wait until now to get the correct value.
for Index in 1 .. Nrefs loop
Xrefs.Table (Index).Def := Sloc (Xrefs.Table (Index).Key.Ent);
end loop;
-- Eliminate entries not appropriate for SPARK. Done prior to sorting
-- cross-references, as it discards useless references which do not have
-- a proper format for the comparison function (like no location).
Ref_Count := Nrefs;
Nrefs := 0;
for Index in 1 .. Ref_Count loop
declare
Ref : Xref_Key renames Xrefs.Table (Index).Key;
begin
if SPARK_Entities (Ekind (Ref.Ent))
and then SPARK_References (Ref.Typ)
and then Is_SPARK_Scope (Ref.Ent_Scope)
and then Is_SPARK_Scope (Ref.Ref_Scope)
and then Is_SPARK_Reference (Ref.Ent, Ref.Typ)
-- Discard references from unknown scopes, e.g. generic scopes
and then Get_Scope_Num (Ref.Ent_Scope) /= No_Scope
and then Get_Scope_Num (Ref.Ref_Scope) /= No_Scope
then
Nrefs := Nrefs + 1;
Rnums (Nrefs) := Index;
end if;
end;
end loop;
-- Sort the references
Sorting.Sort (Integer (Nrefs));
-- Eliminate duplicate entries
-- We need this test for Ref_Count because if we force ALI file
-- generation in case of errors detected, it may be the case that
-- Nrefs is 0, so we should not reset it here.
if Nrefs >= 2 then
Ref_Count := Nrefs;
Nrefs := 1;
for Index in 2 .. Ref_Count loop
if Xrefs.Table (Rnums (Index)) /= Xrefs.Table (Rnums (Nrefs)) then
Nrefs := Nrefs + 1;
Rnums (Nrefs) := Rnums (Index);
end if;
end loop;
end if;
-- Eliminate the reference if it is at the same location as the previous
-- one, unless it is a read-reference indicating that the entity is an
-- in-out actual in a call.
Ref_Count := Nrefs;
Nrefs := 0;
Prev_Loc := No_Location;
Prev_Typ := 'm';
for Index in 1 .. Ref_Count loop
declare
Ref : Xref_Key renames Xrefs.Table (Rnums (Index)).Key;
begin
if Ref.Loc /= Prev_Loc
or else (Prev_Typ = 'm' and then Ref.Typ = 'r')
then
Prev_Loc := Ref.Loc;
Prev_Typ := Ref.Typ;
Nrefs := Nrefs + 1;
Rnums (Nrefs) := Rnums (Index);
end if;
end;
end loop;
-- The two steps have eliminated all references, nothing to do
if SPARK_Scope_Table.Last = 0 then
return;
end if;
Ref_Id := Empty;
Scope_Id := 1;
From_Index := 1;
-- Loop to output references
for Refno in 1 .. Nrefs loop
declare
Ref_Entry : Xref_Entry renames Xrefs.Table (Rnums (Refno));
Ref : Xref_Key renames Ref_Entry.Key;
Typ : Character;
begin
-- If this assertion fails, the scope which we are looking for is
-- not in SPARK scope table, which reveals either a problem in the
-- construction of the scope table, or an erroneous scope for the
-- current cross-reference.
pragma Assert (Is_Future_Scope_Entity (Ref.Ent_Scope, Scope_Id));
-- Update the range of cross references to which the current scope
-- refers to. This may be the empty range only for the first scope
-- considered.
if Ref.Ent_Scope /= Entity_Of_Scope (Scope_Id) then
Update_Scope_Range
(S => Scope_Id,
From => From_Index,
To => SPARK_Xref_Table.Last);
From_Index := SPARK_Xref_Table.Last + 1;
end if;
while Ref.Ent_Scope /= Entity_Of_Scope (Scope_Id) loop
Scope_Id := Scope_Id + 1;
pragma Assert (Scope_Id <= SPARK_Scope_Table.Last);
end loop;
if Ref.Ent /= Ref_Id then
Ref_Name := new String'(Unique_Name (Ref.Ent));
end if;
if Ref.Ent = Heap then
Line := 0;
Col := 0;
else
Line := Nat (Get_Logical_Line_Number (Ref_Entry.Def));
Col := Nat (Get_Column_Number (Ref_Entry.Def));
end if;
-- References to constant objects without variable inputs (see
-- SPARK RM 3.3.1) are considered specially in SPARK section,
-- because these will be translated as constants in the
-- intermediate language for formal verification, and should
-- therefore never appear in frame conditions. Other constants may
-- later be treated the same, up to GNATprove to decide based on
-- its flow analysis.
if Is_Constant_Object_Without_Variable_Input (Ref.Ent) then
Typ := 'c';
else
Typ := Ref.Typ;
end if;
SPARK_Xref_Table.Append (
(Entity_Name => Ref_Name,
Entity_Line => Line,
Etype => Get_Entity_Type (Ref.Ent),
Entity_Col => Col,
File_Num => Dependency_Num (Ref.Lun),
Scope_Num => Get_Scope_Num (Ref.Ref_Scope),
Line => Nat (Get_Logical_Line_Number (Ref.Loc)),
Rtype => Typ,
Col => Nat (Get_Column_Number (Ref.Loc))));
end;
end loop;
-- Update the range of cross references to which the scope refers to
Update_Scope_Range
(S => Scope_Id,
From => From_Index,
To => SPARK_Xref_Table.Last);
end Add_SPARK_Xrefs;
-------------------------
-- Collect_SPARK_Xrefs --
-------------------------
procedure Collect_SPARK_Xrefs
(Sdep_Table : Unit_Ref_Table;
Num_Sdep : Nat)
is
Sdep : Pos;
Sdep_Next : Pos;
-- Index of the current and next source dependency
Sdep_File : Pos;
-- Index of the file to which the scopes need to be assigned; for
-- library-level instances of generic units this points to the unit
-- of the body, because this is where references are assigned to.
Ubody : Unit_Number_Type;
Uspec : Unit_Number_Type;
-- Unit numbers for the dependency spec and possibly its body (only in
-- the case of library-level instance of a generic package).
begin
-- Cross-references should have been computed first
pragma Assert (Xrefs.Last /= 0);
Initialize_SPARK_Tables;
-- Generate file and scope SPARK cross-reference information
Sdep := 1;
while Sdep <= Num_Sdep loop
-- Skip dependencies with no entity node, e.g. configuration files
-- with pragmas (.adc) or target description (.atp), since they
-- present no interest for SPARK cross references.
if No (Cunit_Entity (Sdep_Table (Sdep))) then
Sdep_Next := Sdep + 1;
-- For library-level instantiation of a generic, two consecutive
-- units refer to the same compilation unit node and entity (one to
-- body, one to spec). In that case, treat them as a single unit for
-- the sake of SPARK cross references by passing to Add_SPARK_File.
else
if Sdep < Num_Sdep
and then Cunit_Entity (Sdep_Table (Sdep)) =
Cunit_Entity (Sdep_Table (Sdep + 1))
then
declare
Cunit1 : Node_Id renames Cunit (Sdep_Table (Sdep));
Cunit2 : Node_Id renames Cunit (Sdep_Table (Sdep + 1));
begin
-- Both Cunits point to compilation unit nodes
pragma Assert
(Nkind (Cunit1) = N_Compilation_Unit
and then Nkind (Cunit2) = N_Compilation_Unit);
-- Do not depend on the sorting order, which is based on
-- Unit_Name, and for library-level instances of nested
-- generic packages they are equal.
-- If declaration comes before the body
if Nkind (Unit (Cunit1)) = N_Package_Declaration
and then Nkind (Unit (Cunit2)) = N_Package_Body
then
Uspec := Sdep_Table (Sdep);
Ubody := Sdep_Table (Sdep + 1);
Sdep_File := Sdep + 1;
-- If body comes before declaration
elsif Nkind (Unit (Cunit1)) = N_Package_Body
and then Nkind (Unit (Cunit2)) = N_Package_Declaration
then
Uspec := Sdep_Table (Sdep + 1);
Ubody := Sdep_Table (Sdep);
Sdep_File := Sdep;
-- Otherwise it is an error
else
raise Program_Error;
end if;
Sdep_Next := Sdep + 2;
end;
-- ??? otherwise?
else
Uspec := Sdep_Table (Sdep);
Ubody := No_Unit;
Sdep_File := Sdep;
Sdep_Next := Sdep + 1;
end if;
Add_SPARK_File
(Uspec => Uspec,
Ubody => Ubody,
Dspec => Sdep_File);
end if;
Sdep := Sdep_Next;
end loop;
-- Fill in the spec information when relevant
declare
package Entity_Hash_Table is new
GNAT.HTable.Simple_HTable
(Header_Num => Entity_Hashed_Range,
Element => Scope_Index,
No_Element => 0,
Key => Entity_Id,
Hash => Entity_Hash,
Equal => "=");
begin
-- Fill in the hash-table
for S in SPARK_Scope_Table.First .. SPARK_Scope_Table.Last loop
declare
Srec : SPARK_Scope_Record renames SPARK_Scope_Table.Table (S);
begin
Entity_Hash_Table.Set (Srec.Scope_Entity, S);
end;
end loop;
-- Use the hash-table to locate spec entities
for S in SPARK_Scope_Table.First .. SPARK_Scope_Table.Last loop
declare
Srec : SPARK_Scope_Record renames SPARK_Scope_Table.Table (S);
Spec_Entity : constant Entity_Id :=
Unique_Entity (Srec.Scope_Entity);
Spec_Scope : constant Scope_Index :=
Entity_Hash_Table.Get (Spec_Entity);
begin
-- Generic spec may be missing in which case Spec_Scope is zero
if Spec_Entity /= Srec.Scope_Entity
and then Spec_Scope /= 0
then
Srec.Spec_File_Num :=
SPARK_Scope_Table.Table (Spec_Scope).File_Num;
Srec.Spec_Scope_Num :=
SPARK_Scope_Table.Table (Spec_Scope).Scope_Num;
end if;
end;
end loop;
end;
-- Generate SPARK cross-reference information
Add_SPARK_Xrefs;
end Collect_SPARK_Xrefs;
-------------------------------------
-- Enclosing_Subprogram_Or_Package --
-------------------------------------
function Enclosing_Subprogram_Or_Library_Package
(N : Node_Id) return Entity_Id
is
Context : Entity_Id;
begin
-- If N is the defining identifier for a subprogram, then return the
-- enclosing subprogram or package, not this subprogram.
if Nkind_In (N, N_Defining_Identifier, N_Defining_Operator_Symbol)
and then (Ekind (N) in Entry_Kind
or else Ekind (N) = E_Subprogram_Body
or else Ekind (N) in Generic_Subprogram_Kind
or else Ekind (N) in Subprogram_Kind)
then
Context := Parent (Unit_Declaration_Node (N));
-- If this was a library-level subprogram then replace Context with
-- its Unit, which points to N_Subprogram_* node.
if Nkind (Context) = N_Compilation_Unit then
Context := Unit (Context);
end if;
else
Context := N;
end if;
while Present (Context) loop
case Nkind (Context) is
when N_Package_Body
| N_Package_Specification
=>
-- Only return a library-level package
if Is_Library_Level_Entity (Defining_Entity (Context)) then
Context := Defining_Entity (Context);
exit;
else
Context := Parent (Context);
end if;
when N_Pragma =>
-- The enclosing subprogram for a precondition, postcondition,
-- or contract case should be the declaration preceding the
-- pragma (skipping any other pragmas between this pragma and
-- this declaration.
while Nkind (Context) = N_Pragma
and then Is_List_Member (Context)
and then Present (Prev (Context))
loop
Context := Prev (Context);
end loop;
if Nkind (Context) = N_Pragma then
Context := Parent (Context);
end if;
when N_Entry_Body
| N_Entry_Declaration
| N_Protected_Type_Declaration
| N_Subprogram_Body
| N_Subprogram_Declaration
| N_Subprogram_Specification
| N_Task_Body
| N_Task_Type_Declaration
=>
Context := Defining_Entity (Context);
exit;
when others =>
Context := Parent (Context);
end case;
end loop;
if Nkind (Context) = N_Defining_Program_Unit_Name then
Context := Defining_Identifier (Context);
end if;
-- Do not return a scope without a proper location
if Present (Context)
and then Sloc (Context) = No_Location
then
return Empty;
end if;
return Context;
end Enclosing_Subprogram_Or_Library_Package;
-----------------
-- Entity_Hash --
-----------------
function Entity_Hash (E : Entity_Id) return Entity_Hashed_Range is
begin
return
Entity_Hashed_Range (E mod (Entity_Id (Entity_Hashed_Range'Last) + 1));
end Entity_Hash;
--------------------------
-- Generate_Dereference --
--------------------------
procedure Generate_Dereference
(N : Node_Id;
Typ : Character := 'r')
is
procedure Create_Heap;
-- Create and decorate the special entity which denotes the heap
-----------------
-- Create_Heap --
-----------------
procedure Create_Heap is
begin
Name_Len := Name_Of_Heap_Variable'Length;
Name_Buffer (1 .. Name_Len) := Name_Of_Heap_Variable;
Heap := Make_Defining_Identifier (Standard_Location, Name_Enter);
Set_Ekind (Heap, E_Variable);
Set_Is_Internal (Heap, True);
Set_Has_Fully_Qualified_Name (Heap);
end Create_Heap;
-- Local variables
Loc : constant Source_Ptr := Sloc (N);
-- Start of processing for Generate_Dereference
begin
if Loc > No_Location then
Drefs.Increment_Last;
declare
Deref_Entry : Xref_Entry renames Drefs.Table (Drefs.Last);
Deref : Xref_Key renames Deref_Entry.Key;
begin
if No (Heap) then
Create_Heap;
end if;
Deref.Ent := Heap;
Deref.Loc := Loc;
Deref.Typ := Typ;
-- It is as if the special "Heap" was defined in the main unit,
-- in the scope of the entity for the main unit. This single
-- definition point is required to ensure that sorting cross
-- references works for "Heap" references as well.
Deref.Eun := Main_Unit;
Deref.Lun := Get_Top_Level_Code_Unit (Loc);
Deref.Ref_Scope := Enclosing_Subprogram_Or_Library_Package (N);
Deref.Ent_Scope := Cunit_Entity (Main_Unit);
Deref_Entry.Def := No_Location;
Deref_Entry.Ent_Scope_File := Main_Unit;
end;
end if;
end Generate_Dereference;
-------------------------------
-- Traverse_Compilation_Unit --
-------------------------------
procedure Traverse_Compilation_Unit
(CU : Node_Id;
Inside_Stubs : Boolean)
is
procedure Traverse_Block (N : Node_Id);
procedure Traverse_Declaration_Or_Statement (N : Node_Id);
procedure Traverse_Declarations_And_HSS (N : Node_Id);
procedure Traverse_Declarations_Or_Statements (L : List_Id);
procedure Traverse_Handled_Statement_Sequence (N : Node_Id);
procedure Traverse_Package_Body (N : Node_Id);
procedure Traverse_Visible_And_Private_Parts (N : Node_Id);
procedure Traverse_Protected_Body (N : Node_Id);
procedure Traverse_Subprogram_Body (N : Node_Id);
procedure Traverse_Task_Body (N : Node_Id);
-- Traverse corresponding construct, calling Process on all declarations
--------------------
-- Traverse_Block --
--------------------
procedure Traverse_Block (N : Node_Id) renames
Traverse_Declarations_And_HSS;
---------------------------------------
-- Traverse_Declaration_Or_Statement --
---------------------------------------
procedure Traverse_Declaration_Or_Statement (N : Node_Id) is
function Traverse_Stub (N : Node_Id) return Boolean;
-- Returns True iff stub N should be traversed
function Traverse_Stub (N : Node_Id) return Boolean is
begin
pragma Assert (Nkind_In (N, N_Package_Body_Stub,
N_Protected_Body_Stub,
N_Subprogram_Body_Stub,
N_Task_Body_Stub));
return Inside_Stubs and then Present (Library_Unit (N));
end Traverse_Stub;
-- Start of processing for Traverse_Declaration_Or_Statement
begin
case Nkind (N) is
when N_Package_Declaration =>
Traverse_Visible_And_Private_Parts (Specification (N));
when N_Package_Body =>
Traverse_Package_Body (N);
when N_Package_Body_Stub =>
if Traverse_Stub (N) then
Traverse_Package_Body (Get_Body_From_Stub (N));
end if;
when N_Subprogram_Body =>
Traverse_Subprogram_Body (N);
when N_Entry_Body =>
Traverse_Subprogram_Body (N);
when N_Subprogram_Body_Stub =>
if Traverse_Stub (N) then
Traverse_Subprogram_Body (Get_Body_From_Stub (N));
end if;
when N_Protected_Body =>
Traverse_Protected_Body (N);
when N_Protected_Body_Stub =>
if Traverse_Stub (N) then
Traverse_Protected_Body (Get_Body_From_Stub (N));
end if;
when N_Protected_Type_Declaration =>
Traverse_Visible_And_Private_Parts (Protected_Definition (N));
when N_Task_Definition =>
Traverse_Visible_And_Private_Parts (N);
when N_Task_Body =>
Traverse_Task_Body (N);
when N_Task_Body_Stub =>
if Traverse_Stub (N) then
Traverse_Task_Body (Get_Body_From_Stub (N));
end if;
when N_Block_Statement =>
Traverse_Block (N);
when N_If_Statement =>
-- Traverse the statements in the THEN part
Traverse_Declarations_Or_Statements (Then_Statements (N));
-- Loop through ELSIF parts if present
if Present (Elsif_Parts (N)) then
declare
Elif : Node_Id := First (Elsif_Parts (N));
begin
while Present (Elif) loop
Traverse_Declarations_Or_Statements
(Then_Statements (Elif));
Next (Elif);
end loop;
end;
end if;
-- Finally traverse the ELSE statements if present
Traverse_Declarations_Or_Statements (Else_Statements (N));
when N_Case_Statement =>
-- Process case branches
declare
Alt : Node_Id := First (Alternatives (N));
begin
loop
Traverse_Declarations_Or_Statements (Statements (Alt));
Next (Alt);
exit when No (Alt);
end loop;
end;
when N_Extended_Return_Statement =>
Traverse_Handled_Statement_Sequence
(Handled_Statement_Sequence (N));
when N_Loop_Statement =>
Traverse_Declarations_Or_Statements (Statements (N));
-- Generic declarations are ignored
when others =>
null;
end case;
end Traverse_Declaration_Or_Statement;
-----------------------------------
-- Traverse_Declarations_And_HSS --
-----------------------------------
procedure Traverse_Declarations_And_HSS (N : Node_Id) is
begin
Traverse_Declarations_Or_Statements (Declarations (N));
Traverse_Handled_Statement_Sequence (Handled_Statement_Sequence (N));
end Traverse_Declarations_And_HSS;
-----------------------------------------
-- Traverse_Declarations_Or_Statements --
-----------------------------------------
procedure Traverse_Declarations_Or_Statements (L : List_Id) is
N : Node_Id;
begin
-- Loop through statements or declarations
N := First (L);
while Present (N) loop
-- Call Process on all declarations
if Nkind (N) in N_Declaration
or else Nkind (N) in N_Later_Decl_Item
or else Nkind (N) = N_Entry_Body
then
Process (N);
end if;
Traverse_Declaration_Or_Statement (N);
Next (N);
end loop;
end Traverse_Declarations_Or_Statements;
-----------------------------------------
-- Traverse_Handled_Statement_Sequence --
-----------------------------------------
procedure Traverse_Handled_Statement_Sequence (N : Node_Id) is
Handler : Node_Id;
begin
if Present (N) then
Traverse_Declarations_Or_Statements (Statements (N));
if Present (Exception_Handlers (N)) then
Handler := First (Exception_Handlers (N));
while Present (Handler) loop
Traverse_Declarations_Or_Statements (Statements (Handler));
Next (Handler);
end loop;
end if;
end if;
end Traverse_Handled_Statement_Sequence;
---------------------------
-- Traverse_Package_Body --
---------------------------
procedure Traverse_Package_Body (N : Node_Id) is
Spec_E : constant Entity_Id := Unique_Defining_Entity (N);
begin
case Ekind (Spec_E) is
when E_Package =>
Traverse_Declarations_And_HSS (N);
when E_Generic_Package =>
null;
when others =>
raise Program_Error;
end case;
end Traverse_Package_Body;
-----------------------------
-- Traverse_Protected_Body --
-----------------------------
procedure Traverse_Protected_Body (N : Node_Id) is
begin
Traverse_Declarations_Or_Statements (Declarations (N));
end Traverse_Protected_Body;
------------------------------
-- Traverse_Subprogram_Body --
------------------------------
procedure Traverse_Subprogram_Body (N : Node_Id) is
Spec_E : constant Entity_Id := Unique_Defining_Entity (N);
begin
case Ekind (Spec_E) is
when Entry_Kind
| E_Function
| E_Procedure
=>
Traverse_Declarations_And_HSS (N);
when Generic_Subprogram_Kind =>
null;
when others =>
raise Program_Error;
end case;
end Traverse_Subprogram_Body;
------------------------
-- Traverse_Task_Body --
------------------------
procedure Traverse_Task_Body (N : Node_Id) renames
Traverse_Declarations_And_HSS;
----------------------------------------
-- Traverse_Visible_And_Private_Parts --
----------------------------------------
procedure Traverse_Visible_And_Private_Parts (N : Node_Id) is
begin
Traverse_Declarations_Or_Statements (Visible_Declarations (N));
Traverse_Declarations_Or_Statements (Private_Declarations (N));
end Traverse_Visible_And_Private_Parts;
-- Local variables
Lu : Node_Id;
-- Start of processing for Traverse_Compilation_Unit
begin
-- Get Unit (checking case of subunit)
Lu := Unit (CU);
if Nkind (Lu) = N_Subunit then
Lu := Proper_Body (Lu);
end if;
-- Do not add scopes for generic units
if Nkind (Lu) = N_Package_Body
and then Ekind (Corresponding_Spec (Lu)) in Generic_Unit_Kind
then
return;
end if;
-- Call Process on all declarations
if Nkind (Lu) in N_Declaration
or else Nkind (Lu) in N_Later_Decl_Item
then
Process (Lu);
end if;
-- Traverse the unit
Traverse_Declaration_Or_Statement (Lu);
end Traverse_Compilation_Unit;
end SPARK_Specific;