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gnu / gcc / 19220ca6aa79921cc431e41f25986e16410c7a6a / . / gcc / ada / sem_elab.adb
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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ E L A B --
-- --
-- B o d y --
-- --
-- Copyright (C) 1997-2004 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 2, 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 COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with Atree; use Atree;
with Checks; use Checks;
with Debug; use Debug;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Expander; use Expander;
with Fname; use Fname;
with Lib; use Lib;
with Lib.Load; use Lib.Load;
with Namet; use Namet;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Sem; use Sem;
with Sem_Cat; use Sem_Cat;
with Sem_Ch7; use Sem_Ch7;
with Sem_Ch8; use Sem_Ch8;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sinfo; use Sinfo;
with Sinput; use Sinput;
with Snames; use Snames;
with Stand; use Stand;
with Table;
with Tbuild; use Tbuild;
with Uname; use Uname;
package body Sem_Elab is
-- The following table records the recursive call chain for output
-- in the Output routine. Each entry records the call node and the
-- entity of the called routine. The number of entries in the table
-- (i.e. the value of Elab_Call.Last) indicates the current depth
-- of recursion and is used to identify the outer level.
type Elab_Call_Entry is record
Cloc : Source_Ptr;
Ent : Entity_Id;
end record;
package Elab_Call is new Table.Table (
Table_Component_Type => Elab_Call_Entry,
Table_Index_Type => Int,
Table_Low_Bound => 1,
Table_Initial => 50,
Table_Increment => 100,
Table_Name => "Elab_Call");
-- This table is initialized at the start of each outer level call.
-- It holds the entities for all subprograms that have been examined
-- for this particular outer level call, and is used to prevent both
-- infinite recursion, and useless reanalysis of bodies already seen
package Elab_Visited is new Table.Table (
Table_Component_Type => Entity_Id,
Table_Index_Type => Int,
Table_Low_Bound => 1,
Table_Initial => 200,
Table_Increment => 100,
Table_Name => "Elab_Visited");
-- This table stores calls to Check_Internal_Call that are delayed
-- until all generics are instantiated, and in particular that all
-- generic bodies have been inserted. We need to delay, because we
-- need to be able to look through the inserted bodies.
type Delay_Element is record
N : Node_Id;
-- The parameter N from the call to Check_Internal_Call. Note that
-- this node may get rewritten over the delay period by expansion
-- in the call case (but not in the instantiation case).
E : Entity_Id;
-- The parameter E from the call to Check_Internal_Call
Orig_Ent : Entity_Id;
-- The parameter Orig_Ent from the call to Check_Internal_Call
Curscop : Entity_Id;
-- The current scope of the call. This is restored when we complete
-- the delayed call, so that we do this in the right scope.
From_Elab_Code : Boolean;
-- Save indication of whether this call is from elaboration code
Outer_Scope : Entity_Id;
-- Save scope of outer level call
end record;
package Delay_Check is new Table.Table (
Table_Component_Type => Delay_Element,
Table_Index_Type => Int,
Table_Low_Bound => 1,
Table_Initial => 1000,
Table_Increment => 100,
Table_Name => "Delay_Check");
C_Scope : Entity_Id;
-- Top level scope of current scope. We need to compute this only
-- once at the outer level, i.e. for a call to Check_Elab_Call from
-- outside this unit.
Outer_Level_Sloc : Source_Ptr;
-- Save Sloc value for outer level call node for comparisons of source
-- locations. A body is too late if it appears after the *outer* level
-- call, not the particular call that is being analyzed.
From_Elab_Code : Boolean;
-- This flag shows whether the outer level call currently being examined
-- is or is not in elaboration code. We are only interested in calls to
-- routines in other units if this flag is True.
In_Task_Activation : Boolean := False;
-- This flag indicates whether we are performing elaboration checks on
-- task procedures, at the point of activation. If true, we do not trace
-- internal calls in these procedures, because all local bodies are known
-- to be elaborated.
Delaying_Elab_Checks : Boolean := True;
-- This is set True till the compilation is complete, including the
-- insertion of all instance bodies. Then when Check_Elab_Calls is
-- called, the delay table is used to make the delayed calls and
-- this flag is reset to False, so that the calls are processed
-----------------------
-- Local Subprograms --
-----------------------
-- Note: Outer_Scope in all these calls represents the scope of
-- interest of the outer level call. If it is set to Standard_Standard,
-- then it means the outer level call was at elaboration level, and that
-- thus all calls are of interest. If it was set to some other scope,
-- then the original call was an inner call, and we are not interested
-- in calls that go outside this scope.
procedure Check_A_Call
(N : Node_Id;
E : Entity_Id;
Outer_Scope : Entity_Id;
Inter_Unit_Only : Boolean;
Generate_Warnings : Boolean := True);
-- This is the internal recursive routine that is called to check for
-- a possible elaboration error. The argument N is a subprogram call
-- or generic instantiation to be checked, and E is the entity of
-- the called subprogram, or instantiated generic unit. The flag
-- Outer_Scope is the outer level scope for the original call.
-- Inter_Unit_Only is set if the call is only to be checked in the
-- case where it is to another unit (and skipped if within a unit).
-- Generate_Warnings is set to False to suppress warning messages
-- about missing pragma Elaborate_All's. These messages are not
-- wanted for inner calls in the dynamic model.
procedure Check_Bad_Instantiation (N : Node_Id);
-- N is a node for an instantiation (if called with any other node kind,
-- Check_Bad_Instantiation ignores the call). This subprogram checks for
-- the special case of a generic instantiation of a generic spec in the
-- same declarative part as the instantiation where a body is present and
-- has not yet been seen. This is an obvious error, but needs to be checked
-- specially at the time of the instantiation, since it is a case where we
-- cannot insert the body anywhere. If this case is detected, warnings are
-- generated, and a raise of Program_Error is inserted. In addition any
-- subprograms in the generic spec are stubbed, and the Bad_Instantiation
-- flag is set on the instantiation node. The caller in Sem_Ch12 uses this
-- flag as an indication that no attempt should be made to insert an
-- instance body.
procedure Check_Internal_Call
(N : Node_Id;
E : Entity_Id;
Outer_Scope : Entity_Id;
Orig_Ent : Entity_Id);
-- N is a function call or procedure statement call node and E is
-- the entity of the called function, which is within the current
-- compilation unit (where subunits count as part of the parent).
-- This call checks if this call, or any call within any accessed
-- body could cause an ABE, and if so, outputs a warning. Orig_Ent
-- differs from E only in the case of renamings, and points to the
-- original name of the entity. This is used for error messages.
-- Outer_Scope is the outer level scope for the original call.
procedure Check_Internal_Call_Continue
(N : Node_Id;
E : Entity_Id;
Outer_Scope : Entity_Id;
Orig_Ent : Entity_Id);
-- The processing for Check_Internal_Call is divided up into two phases,
-- and this represents the second phase. The second phase is delayed if
-- Delaying_Elab_Calls is set to True. In this delayed case, the first
-- phase makes an entry in the Delay_Check table, which is processed
-- when Check_Elab_Calls is called. N, E and Orig_Ent are as for the call
-- to Check_Internal_Call. Outer_Scope is the outer level scope for
-- the original call.
function Has_Generic_Body (N : Node_Id) return Boolean;
-- N is a generic package instantiation node, and this routine determines
-- if this package spec does in fact have a generic body. If so, then
-- True is returned, otherwise False. Note that this is not at all the
-- same as checking if the unit requires a body, since it deals with
-- the case of optional bodies accurately (i.e. if a body is optional,
-- then it looks to see if a body is actually present). Note: this
-- function can only do a fully correct job if in generating code mode
-- where all bodies have to be present. If we are operating in semantics
-- check only mode, then in some cases of optional bodies, a result of
-- False may incorrectly be given. In practice this simply means that
-- some cases of warnings for incorrect order of elaboration will only
-- be given when generating code, which is not a big problem (and is
-- inevitable, given the optional body semantics of Ada).
procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty);
-- Given code for an elaboration check (or unconditional raise if
-- the check is not needed), inserts the code in the appropriate
-- place. N is the call or instantiation node for which the check
-- code is required. C is the test whose failure triggers the raise.
procedure Output_Calls (N : Node_Id);
-- Outputs chain of calls stored in the Elab_Call table. The caller
-- has already generated the main warning message, so the warnings
-- generated are all continuation messages. The argument is the
-- call node at which the messages are to be placed.
function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean;
-- Given two scopes, determine whether they are the same scope from an
-- elaboration point of view, i.e. packages and blocks are ignored.
procedure Set_C_Scope;
-- On entry C_Scope is set to some scope. On return, C_Scope is reset
-- to be the enclosing compilation unit of this scope.
function Spec_Entity (E : Entity_Id) return Entity_Id;
-- Given a compilation unit entity, if it is a spec entity, it is
-- returned unchanged. If it is a body entity, then the spec for
-- the corresponding spec is returned
procedure Supply_Bodies (N : Node_Id);
-- Given a node, N, that is either a subprogram declaration or a package
-- declaration, this procedure supplies dummy bodies for the subprogram
-- or for all subprograms in the package. If the given node is not one
-- of these two possibilities, then Supply_Bodies does nothing. The
-- dummy body is supplied by setting the subprogram to be Imported with
-- convention Stubbed.
procedure Supply_Bodies (L : List_Id);
-- Calls Supply_Bodies for all elements of the given list L.
function Within (E1, E2 : Entity_Id) return Boolean;
-- Given two scopes E1 and E2, returns True if E1 is equal to E2, or
-- is one of its contained scopes, False otherwise.
function Within_Elaborate_All (E : Entity_Id) return Boolean;
-- Before emitting a warning on a scope E for a missing elaborate_all,
-- check whether E may be in the context of a directly visible unit
-- U to which the pragma applies. This prevents spurious warnings when
-- the called entity is renamed within U.
------------------
-- Check_A_Call --
------------------
procedure Check_A_Call
(N : Node_Id;
E : Entity_Id;
Outer_Scope : Entity_Id;
Inter_Unit_Only : Boolean;
Generate_Warnings : Boolean := True)
is
Loc : constant Source_Ptr := Sloc (N);
Ent : Entity_Id;
Decl : Node_Id;
E_Scope : Entity_Id;
-- Top level scope of entity for called subprogram. This
-- value includes following renamings and derivations, so
-- this scope can be in a non-visible unit. This is the
-- scope that is to be investigated to see whether an
-- elaboration check is required.
W_Scope : Entity_Id;
-- Top level scope of directly called entity for subprogram.
-- This differs from E_Scope in the case where renamings or
-- derivations are involved, since it does not follow these
-- links, thus W_Scope is always in a visible unit. This is
-- the scope for the Elaborate_All if one is needed.
Body_Acts_As_Spec : Boolean;
-- Set to true if call is to body acting as spec (no separate spec)
Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation;
-- Indicates if we have instantiation case
Caller_Unit_Internal : Boolean;
Callee_Unit_Internal : Boolean;
Inst_Caller : Source_Ptr;
Inst_Callee : Source_Ptr;
Unit_Caller : Unit_Number_Type;
Unit_Callee : Unit_Number_Type;
Cunit_SC : Boolean := False;
-- Set to suppress dynamic elaboration checks where one of the
-- enclosing scopes has Elaboration_Checks_Suppressed set, or else
-- if a pragma Elaborate (_All) applies to that scope, in which case
-- warnings on the scope are also suppressed. For the internal case,
-- we ignore this flag.
begin
-- If the call is known to be within a local Suppress Elaboration
-- pragma, nothing to check. This can happen in task bodies.
if (Nkind (N) = N_Function_Call
or else Nkind (N) = N_Procedure_Call_Statement)
and then No_Elaboration_Check (N)
then
return;
end if;
-- Go to parent for derived subprogram, or to original subprogram
-- in the case of a renaming (Alias covers both these cases)
Ent := E;
loop
if (Suppress_Elaboration_Warnings (Ent)
or else Elaboration_Checks_Suppressed (Ent))
and then (Inst_Case or else No (Alias (Ent)))
then
return;
end if;
-- Nothing to do for imported entities,
if Is_Imported (Ent) then
return;
end if;
exit when Inst_Case or else No (Alias (Ent));
Ent := Alias (Ent);
end loop;
Decl := Unit_Declaration_Node (Ent);
if Nkind (Decl) = N_Subprogram_Body then
Body_Acts_As_Spec := True;
elsif Nkind (Decl) = N_Subprogram_Declaration
or else Nkind (Decl) = N_Subprogram_Body_Stub
or else Inst_Case
then
Body_Acts_As_Spec := False;
-- If we have none of an instantiation, subprogram body or
-- subprogram declaration, then it is not a case that we want
-- to check. (One case is a call to a generic formal subprogram,
-- where we do not want the check in the template).
else
return;
end if;
E_Scope := Ent;
loop
if Elaboration_Checks_Suppressed (E_Scope)
or else Suppress_Elaboration_Warnings (E_Scope)
then
Cunit_SC := True;
end if;
-- Exit when we get to compilation unit, not counting subunits
exit when Is_Compilation_Unit (E_Scope)
and then (Is_Child_Unit (E_Scope)
or else Scope (E_Scope) = Standard_Standard);
-- If we did not find a compilation unit, other than standard,
-- then nothing to check (happens in some instantiation cases)
if E_Scope = Standard_Standard then
return;
-- Otherwise move up a scope looking for compilation unit
else
E_Scope := Scope (E_Scope);
end if;
end loop;
-- No checks needed for pure or preelaborated compilation units
if Is_Pure (E_Scope)
or else Is_Preelaborated (E_Scope)
then
return;
end if;
-- If the generic entity is within a deeper instance than we are, then
-- either the instantiation to which we refer itself caused an ABE, in
-- which case that will be handled separately. Otherwise, we know that
-- the body we need appears as needed at the point of the instantiation.
-- However, this assumption is only valid if we are in static mode.
if not Dynamic_Elaboration_Checks
and then Instantiation_Depth (Sloc (Ent)) >
Instantiation_Depth (Sloc (N))
then
return;
end if;
-- Do not give a warning for a package with no body
if Ekind (Ent) = E_Generic_Package
and then not Has_Generic_Body (N)
then
return;
end if;
-- Case of entity is not in current unit (i.e. with'ed unit case)
if E_Scope /= C_Scope then
-- We are only interested in such calls if the outer call was from
-- elaboration code, or if we are in Dynamic_Elaboration_Checks mode.
if not From_Elab_Code and then not Dynamic_Elaboration_Checks then
return;
end if;
-- Nothing to do if some scope said that no checks were required
if Cunit_SC then
return;
end if;
-- Nothing to do for a generic instance, because in this case
-- the checking was at the point of instantiation of the generic
-- However, this shortcut is only applicable in static mode.
if Is_Generic_Instance (Ent) and not Dynamic_Elaboration_Checks then
return;
end if;
-- Nothing to do if subprogram with no separate spec. However,
-- a call to Deep_Initialize may result in a call to a user-defined
-- Initialize procedure, which imposes a body dependency. This
-- happens only if the type is controlled and the Initialize
-- procedure is not inherited.
if Body_Acts_As_Spec then
if Is_TSS (Ent, TSS_Deep_Initialize) then
declare
Typ : Entity_Id;
Init : Entity_Id;
begin
Typ := Etype (Next_Formal (First_Formal (Ent)));
if not Is_Controlled (Typ) then
return;
else
Init := Find_Prim_Op (Typ, Name_Initialize);
if Comes_From_Source (Init) then
Ent := Init;
else
return;
end if;
end if;
end;
else
return;
end if;
end if;
-- Check cases of internal units
Callee_Unit_Internal :=
Is_Internal_File_Name
(Unit_File_Name (Get_Source_Unit (E_Scope)));
-- Do not give a warning if the with'ed unit is internal
-- and this is the generic instantiation case (this saves a
-- lot of hassle dealing with the Text_IO special child units)
if Callee_Unit_Internal and Inst_Case then
return;
end if;
if C_Scope = Standard_Standard then
Caller_Unit_Internal := False;
else
Caller_Unit_Internal :=
Is_Internal_File_Name
(Unit_File_Name (Get_Source_Unit (C_Scope)));
end if;
-- Do not give a warning if the with'ed unit is internal
-- and the caller is not internal (since the binder always
-- elaborates internal units first).
if Callee_Unit_Internal and (not Caller_Unit_Internal) then
return;
end if;
-- For now, if debug flag -gnatdE is not set, do no checking for
-- one internal unit withing another. This fixes the problem with
-- the sgi build and storage errors. To be resolved later ???
if (Callee_Unit_Internal and Caller_Unit_Internal)
and then not Debug_Flag_EE
then
return;
end if;
if Is_TSS (E, TSS_Deep_Initialize) then
Ent := E;
end if;
-- If the call is in an instance, and the called entity is not
-- defined in the same instance, then the elaboration issue
-- focuses around the unit containing the template, it is
-- this unit which requires an Elaborate_All.
-- However, if we are doing dynamic elaboration, we need to
-- chase the call in the usual manner.
-- We do not handle the case of calling a generic formal correctly
-- in the static case. See test 4703-004 to explore this gap ???
Inst_Caller := Instantiation (Get_Source_File_Index (Sloc (N)));
Inst_Callee := Instantiation (Get_Source_File_Index (Sloc (Ent)));
if Inst_Caller = No_Location then
Unit_Caller := No_Unit;
else
Unit_Caller := Get_Source_Unit (N);
end if;
if Inst_Callee = No_Location then
Unit_Callee := No_Unit;
else
Unit_Callee := Get_Source_Unit (Ent);
end if;
if Unit_Caller /= No_Unit
and then Unit_Callee /= Unit_Caller
and then not Dynamic_Elaboration_Checks
then
E_Scope := Spec_Entity (Cunit_Entity (Unit_Caller));
-- If we don't get a spec entity, just ignore call. Not
-- quite clear why this check is necessary.
if No (E_Scope) then
return;
end if;
-- Otherwise step to enclosing compilation unit
while not Is_Compilation_Unit (E_Scope) loop
E_Scope := Scope (E_Scope);
end loop;
-- For the case N is not an instance, or a call within instance
-- We recompute E_Scope for the error message, since we
-- do NOT want to go to the unit which has the ultimate
-- declaration in the case of renaming and derivation and
-- we also want to go to the generic unit in the case of
-- an instance, and no further.
else
-- Loop to carefully follow renamings and derivations
-- one step outside the current unit, but not further.
if not Inst_Case
and then Present (Alias (Ent))
then
E_Scope := Alias (Ent);
else
E_Scope := Ent;
end if;
loop
while not Is_Compilation_Unit (E_Scope) loop
E_Scope := Scope (E_Scope);
end loop;
-- If E_Scope is the same as C_Scope, it means that there
-- definitely was a local renaming or derivation, and we
-- are not yet out of the current unit.
exit when E_Scope /= C_Scope;
Ent := Alias (Ent);
E_Scope := Ent;
-- If no alias, there is a previous error
if No (Ent) then
return;
end if;
end loop;
end if;
if Within_Elaborate_All (E_Scope) then
return;
end if;
-- Find top level scope for called entity (not following renamings
-- or derivations). This is where the Elaborate_All will go if it
-- is needed. We start with the called entity, except in the case
-- of initialization procedures, where the init proc is in the root
-- package, where we start fromn the entity of the name in the call.
if Is_Entity_Name (Name (N))
and then Is_Init_Proc (Entity (Name (N)))
then
W_Scope := Scope (Entity (Name (N)));
else
W_Scope := E;
end if;
while not Is_Compilation_Unit (W_Scope) loop
W_Scope := Scope (W_Scope);
end loop;
-- Now check if an elaborate_all (or dynamic check) is needed
if not Suppress_Elaboration_Warnings (Ent)
and then not Elaboration_Checks_Suppressed (Ent)
and then not Suppress_Elaboration_Warnings (E_Scope)
and then not Elaboration_Checks_Suppressed (E_Scope)
and then Elab_Warnings
and then Generate_Warnings
then
if Inst_Case then
Error_Msg_NE
("instantiation of& may raise Program_Error?", N, Ent);
else
if Is_Init_Proc (Entity (Name (N)))
and then Comes_From_Source (Ent)
then
Error_Msg_NE
("implicit call to & may raise Program_Error?", N, Ent);
else
Error_Msg_NE
("call to & may raise Program_Error?", N, Ent);
end if;
end if;
Error_Msg_Qual_Level := Nat'Last;
Error_Msg_NE
("\missing pragma Elaborate_All for&?", N, W_Scope);
Error_Msg_Qual_Level := 0;
Output_Calls (N);
-- Set flag to prevent further warnings for same unit
-- unless in All_Errors_Mode.
if not All_Errors_Mode and not Dynamic_Elaboration_Checks then
Set_Suppress_Elaboration_Warnings (W_Scope, True);
end if;
end if;
-- Check for runtime elaboration check required
if Dynamic_Elaboration_Checks then
if not Elaboration_Checks_Suppressed (Ent)
and then not Elaboration_Checks_Suppressed (W_Scope)
and then not Elaboration_Checks_Suppressed (E_Scope)
and then not Cunit_SC
then
-- Runtime elaboration check required. Generate check of the
-- elaboration Boolean for the unit containing the entity.
-- Note that for this case, we do check the real unit (the
-- one from following renamings, since that is the issue!)
-- Could this possibly miss a useless but required PE???
Insert_Elab_Check (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Elaborated,
Prefix =>
New_Occurrence_Of
(Spec_Entity (E_Scope), Loc)));
end if;
-- Case of static elaboration model
else
-- Do not do anything if elaboration checks suppressed. Note
-- that we check Ent here, not E, since we want the real entity
-- for the body to see if checks are suppressed for it, not the
-- dummy entry for renamings or derivations.
if Elaboration_Checks_Suppressed (Ent)
or else Elaboration_Checks_Suppressed (E_Scope)
or else Elaboration_Checks_Suppressed (W_Scope)
then
null;
-- Here we need to generate an implicit elaborate all
else
-- Generate elaborate_all warning unless suppressed
if (Elab_Warnings and Generate_Warnings and not Inst_Case)
and then not Suppress_Elaboration_Warnings (Ent)
and then not Suppress_Elaboration_Warnings (E_Scope)
and then not Suppress_Elaboration_Warnings (W_Scope)
then
Error_Msg_Node_2 := W_Scope;
Error_Msg_NE
("call to& in elaboration code " &
"requires pragma Elaborate_All on&?", N, E);
end if;
-- Set indication for binder to generate Elaborate_All
Set_Elaborate_All_Desirable (W_Scope);
Set_Suppress_Elaboration_Warnings (W_Scope, True);
end if;
end if;
-- Case of entity is in same unit as call or instantiation
elsif not Inter_Unit_Only then
Check_Internal_Call (N, Ent, Outer_Scope, E);
end if;
end Check_A_Call;
-----------------------------
-- Check_Bad_Instantiation --
-----------------------------
procedure Check_Bad_Instantiation (N : Node_Id) is
Ent : Entity_Id;
begin
-- Nothing to do if we do not have an instantiation (happens in some
-- error cases, and also in the formal package declaration case)
if Nkind (N) not in N_Generic_Instantiation then
return;
-- Nothing to do if serious errors detected (avoid cascaded errors)
elsif Serious_Errors_Detected /= 0 then
return;
-- Nothing to do if not in full analysis mode
elsif not Full_Analysis then
return;
-- Nothing to do if inside a generic template
elsif Inside_A_Generic then
return;
-- Nothing to do if a library level instantiation
elsif Nkind (Parent (N)) = N_Compilation_Unit then
return;
-- Nothing to do if we are compiling a proper body for semantic
-- purposes only. The generic body may be in another proper body.
elsif
Nkind (Parent (Unit_Declaration_Node (Main_Unit_Entity))) = N_Subunit
then
return;
end if;
Ent := Get_Generic_Entity (N);
-- The case we are interested in is when the generic spec is in the
-- current declarative part
if not Same_Elaboration_Scope (Current_Scope, Scope (Ent))
or else not In_Same_Extended_Unit (Sloc (N), Sloc (Ent))
then
return;
end if;
-- If the generic entity is within a deeper instance than we are, then
-- either the instantiation to which we refer itself caused an ABE, in
-- which case that will be handled separately. Otherwise, we know that
-- the body we need appears as needed at the point of the instantiation.
-- If they are both at the same level but not within the same instance
-- then the body of the generic will be in the earlier instance.
declare
D1 : constant Int := Instantiation_Depth (Sloc (Ent));
D2 : constant Int := Instantiation_Depth (Sloc (N));
begin
if D1 > D2 then
return;
elsif D1 = D2
and then Is_Generic_Instance (Scope (Ent))
and then not In_Open_Scopes (Scope (Ent))
then
return;
end if;
end;
-- Now we can proceed, if the entity being called has a completion,
-- then we are definitely OK, since we have already seen the body.
if Has_Completion (Ent) then
return;
end if;
-- If there is no body, then nothing to do
if not Has_Generic_Body (N) then
return;
end if;
-- Here we definitely have a bad instantiation
Error_Msg_NE
("?cannot instantiate& before body seen", N, Ent);
if Present (Instance_Spec (N)) then
Supply_Bodies (Instance_Spec (N));
end if;
Error_Msg_N
("\?Program_Error will be raised at run time", N);
Insert_Elab_Check (N);
Set_ABE_Is_Certain (N);
end Check_Bad_Instantiation;
---------------------
-- Check_Elab_Call --
---------------------
procedure Check_Elab_Call
(N : Node_Id;
Outer_Scope : Entity_Id := Empty)
is
Ent : Entity_Id;
P : Node_Id;
function Get_Called_Ent return Entity_Id;
-- Retrieve called entity. If this is a call to a protected subprogram,
-- entity is a selected component. The callable entity may be absent,
-- in which case there is no check to perform. This happens with
-- non-analyzed calls in nested generics.
--------------------
-- Get_Called_Ent --
--------------------
function Get_Called_Ent return Entity_Id is
Nam : Node_Id;
begin
Nam := Name (N);
if No (Nam) then
return Empty;
elsif Nkind (Nam) = N_Selected_Component then
return Entity (Selector_Name (Nam));
elsif not Is_Entity_Name (Nam) then
return Empty;
else
return Entity (Nam);
end if;
end Get_Called_Ent;
-- Start of processing for Check_Elab_Call
begin
-- For an entry call, check relevant restriction
if Nkind (N) = N_Entry_Call_Statement
and then not In_Subprogram_Or_Concurrent_Unit
then
Check_Restriction (No_Entry_Calls_In_Elaboration_Code, N);
-- Nothing to do if this is not a call (happens in some error
-- conditions, and in some cases where rewriting occurs).
elsif Nkind (N) /= N_Function_Call
and then Nkind (N) /= N_Procedure_Call_Statement
then
return;
-- Nothing to do if this is a call already rewritten for elab checking.
elsif Nkind (Parent (N)) = N_Conditional_Expression then
return;
-- Nothing to do if inside a generic template
elsif Inside_A_Generic
and then not Present (Enclosing_Generic_Body (N))
then
return;
end if;
-- Here we have a call at elaboration time which must be checked
if Debug_Flag_LL then
Write_Str (" Check_Elab_Call: ");
if No (Name (N))
or else not Is_Entity_Name (Name (N))
then
Write_Str ("<<not entity name>> ");
else
Write_Name (Chars (Entity (Name (N))));
end if;
Write_Str (" call at ");
Write_Location (Sloc (N));
Write_Eol;
end if;
-- Climb up the tree to make sure we are not inside a
-- default expression of a parameter specification or
-- a record component, since in both these cases, we
-- will be doing the actual call later, not now, and it
-- is at the time of the actual call (statically speaking)
-- that we must do our static check, not at the time of
-- its initial analysis).
P := Parent (N);
while Present (P) loop
if Nkind (P) = N_Parameter_Specification
or else
Nkind (P) = N_Component_Declaration
then
return;
else
P := Parent (P);
end if;
end loop;
-- Stuff that happens only at the outer level
if No (Outer_Scope) then
Elab_Visited.Set_Last (0);
-- Nothing to do if current scope is Standard (this is a bit
-- odd, but it happens in the case of generic instantiations).
C_Scope := Current_Scope;
if C_Scope = Standard_Standard then
return;
end if;
-- First case, we are in elaboration code
From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit;
if From_Elab_Code then
-- Complain if call that comes from source in preelaborated
-- unit and we are not inside a subprogram (i.e. we are in
-- elab code)
if Comes_From_Source (N)
and then In_Preelaborated_Unit
and then not In_Inlined_Body
then
Error_Msg_N
("non-static call not allowed in preelaborated unit", N);
return;
end if;
-- Second case, we are inside a subprogram or concurrent unit
-- i.e, we are not in elaboration code.
else
-- In this case, the issue is whether we are inside the
-- declarative part of the unit in which we live, or inside
-- its statements. In the latter case, there is no issue of
-- ABE calls at this level (a call from outside to the unit
-- in which we live might cause an ABE, but that will be
-- detected when we analyze that outer level call, as it
-- recurses into the called unit).
-- Climb up the tree, doing this test, and also testing
-- for being inside a default expression, which, as
-- discussed above, is not checked at this stage.
declare
P : Node_Id;
L : List_Id;
begin
P := N;
loop
-- If we find a parentless subtree, it seems safe to
-- assume that we are not in a declarative part and
-- that no checking is required.
if No (P) then
return;
end if;
if Is_List_Member (P) then
L := List_Containing (P);
P := Parent (L);
else
L := No_List;
P := Parent (P);
end if;
exit when Nkind (P) = N_Subunit;
-- Filter out case of default expressions, where
-- we do not do the check at this stage.
if Nkind (P) = N_Parameter_Specification
or else
Nkind (P) = N_Component_Declaration
then
return;
end if;
if Nkind (P) = N_Subprogram_Body
or else
Nkind (P) = N_Protected_Body
or else
Nkind (P) = N_Task_Body
or else
Nkind (P) = N_Block_Statement
then
if L = Declarations (P) then
exit;
-- We are not in elaboration code, but we are doing
-- dynamic elaboration checks, in this case, we still
-- need to do the call, since the subprogram we are in
-- could be called from another unit, also in dynamic
-- elaboration check mode, at elaboration time.
elsif Dynamic_Elaboration_Checks then
-- This is a rather new check, going into version
-- 3.14a1 for the first time (V1.80 of this unit),
-- so we provide a debug flag to enable it. That
-- way we have an easy work around for regressions
-- that are caused by this new check. This debug
-- flag can be removed later.
if Debug_Flag_DD then
return;
end if;
-- Do the check in this case
exit;
elsif Nkind (P) = N_Task_Body then
-- The check is deferred until Check_Task_Activation
-- but we need to capture local suppress pragmas
-- that may inhibit checks on this call.
Ent := Get_Called_Ent;
if No (Ent) then
return;
elsif Elaboration_Checks_Suppressed (Current_Scope)
or else Elaboration_Checks_Suppressed (Ent)
or else Elaboration_Checks_Suppressed (Scope (Ent))
then
Set_No_Elaboration_Check (N);
end if;
return;
-- Static model, call is not in elaboration code, we
-- never need to worry, because in the static model
-- the top level caller always takes care of things.
else
return;
end if;
end if;
end loop;
end;
end if;
end if;
Ent := Get_Called_Ent;
if No (Ent) then
return;
end if;
-- Nothing to do if this is a recursive call (i.e. a call to
-- an entity that is already in the Elab_Call stack)
for J in 1 .. Elab_Visited.Last loop
if Ent = Elab_Visited.Table (J) then
return;
end if;
end loop;
-- See if we need to analyze this call. We analyze it if either of
-- the following conditions is met:
-- It is an inner level call (since in this case it was triggered
-- by an outer level call from elaboration code), but only if the
-- call is within the scope of the original outer level call.
-- It is an outer level call from elaboration code, or the called
-- entity is in the same elaboration scope.
-- And in these cases, we will check both inter-unit calls and
-- intra-unit (within a single unit) calls.
C_Scope := Current_Scope;
-- If not outer level call, then we follow it if it is within
-- the original scope of the outer call.
if Present (Outer_Scope)
and then Within (Scope (Ent), Outer_Scope)
then
Set_C_Scope;
Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False);
elsif Elaboration_Checks_Suppressed (Current_Scope) then
null;
elsif From_Elab_Code then
Set_C_Scope;
Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False);
elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then
Set_C_Scope;
Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False);
-- If none of those cases holds, but Dynamic_Elaboration_Checks mode
-- is set, then we will do the check, but only in the inter-unit case
-- (this is to accommodate unguarded elaboration calls from other units
-- in which this same mode is set). We don't want warnings in this case,
-- it would generate warnings having nothing to do with elaboration.
elsif Dynamic_Elaboration_Checks then
Set_C_Scope;
Check_A_Call
(N,
Ent,
Standard_Standard,
Inter_Unit_Only => True,
Generate_Warnings => False);
-- Otherwise nothing to do
else
return;
end if;
-- A call to an Init_Proc in elaboration code may bring additional
-- dependencies, if some of the record components thereof have
-- initializations that are function calls that come from source.
-- We treat the current node as a call to each of these functions,
-- to check their elaboration impact.
if Is_Init_Proc (Ent)
and then From_Elab_Code
then
Process_Init_Proc : declare
Unit_Decl : constant Node_Id := Unit_Declaration_Node (Ent);
function Process (Nod : Node_Id) return Traverse_Result;
-- Find subprogram calls within body of init_proc for
-- Traverse instantiation below.
function Process (Nod : Node_Id) return Traverse_Result is
Func : Entity_Id;
begin
if (Nkind (Nod) = N_Function_Call
or else Nkind (Nod) = N_Procedure_Call_Statement)
and then Is_Entity_Name (Name (Nod))
then
Func := Entity (Name (Nod));
if Comes_From_Source (Func) then
Check_A_Call
(N, Func, Standard_Standard, Inter_Unit_Only => True);
end if;
return OK;
else
return OK;
end if;
end Process;
procedure Traverse_Body is new Traverse_Proc (Process);
-- Start of processing for Process_Init_Proc
begin
if Nkind (Unit_Decl) = N_Subprogram_Body then
Traverse_Body (Handled_Statement_Sequence (Unit_Decl));
end if;
end Process_Init_Proc;
end if;
end Check_Elab_Call;
----------------------
-- Check_Elab_Calls --
----------------------
procedure Check_Elab_Calls is
begin
-- If expansion is disabled, do not generate any checks. Also
-- skip checks if any subunits are missing because in either
-- case we lack the full information that we need, and no object
-- file will be created in any case.
if not Expander_Active
or else Is_Generic_Unit (Cunit_Entity (Main_Unit))
or else Subunits_Missing
then
return;
end if;
-- Skip delayed calls if we had any errors
if Serious_Errors_Detected = 0 then
Delaying_Elab_Checks := False;
Expander_Mode_Save_And_Set (True);
for J in Delay_Check.First .. Delay_Check.Last loop
New_Scope (Delay_Check.Table (J).Curscop);
From_Elab_Code := Delay_Check.Table (J).From_Elab_Code;
Check_Internal_Call_Continue (
N => Delay_Check.Table (J).N,
E => Delay_Check.Table (J).E,
Outer_Scope => Delay_Check.Table (J).Outer_Scope,
Orig_Ent => Delay_Check.Table (J).Orig_Ent);
Pop_Scope;
end loop;
-- Set Delaying_Elab_Checks back on for next main compilation
Expander_Mode_Restore;
Delaying_Elab_Checks := True;
end if;
end Check_Elab_Calls;
------------------------------
-- Check_Elab_Instantiation --
------------------------------
procedure Check_Elab_Instantiation
(N : Node_Id;
Outer_Scope : Entity_Id := Empty)
is
Ent : Entity_Id;
begin
-- Check for and deal with bad instantiation case. There is some
-- duplicated code here, but we will worry about this later ???
Check_Bad_Instantiation (N);
if ABE_Is_Certain (N) then
return;
end if;
-- Nothing to do if we do not have an instantiation (happens in some
-- error cases, and also in the formal package declaration case)
if Nkind (N) not in N_Generic_Instantiation then
return;
end if;
-- Nothing to do if inside a generic template
if Inside_A_Generic then
return;
end if;
Ent := Get_Generic_Entity (N);
From_Elab_Code := not In_Subprogram_Or_Concurrent_Unit;
-- See if we need to analyze this instantiation. We analyze it if
-- either of the following conditions is met:
-- It is an inner level instantiation (since in this case it was
-- triggered by an outer level call from elaboration code), but
-- only if the instantiation is within the scope of the original
-- outer level call.
-- It is an outer level instantiation from elaboration code, or the
-- instantiated entity is in the same elaboratoin scope.
-- And in these cases, we will check both the inter-unit case and
-- the intra-unit (within a single unit) case.
C_Scope := Current_Scope;
if Present (Outer_Scope)
and then Within (Scope (Ent), Outer_Scope)
then
Set_C_Scope;
Check_A_Call (N, Ent, Outer_Scope, Inter_Unit_Only => False);
elsif From_Elab_Code then
Set_C_Scope;
Check_A_Call (N, Ent, Standard_Standard, Inter_Unit_Only => False);
elsif Same_Elaboration_Scope (C_Scope, Scope (Ent)) then
Set_C_Scope;
Check_A_Call (N, Ent, Scope (Ent), Inter_Unit_Only => False);
-- If none of those cases holds, but Dynamic_Elaboration_Checks mode
-- is set, then we will do the check, but only in the inter-unit case
-- (this is to accommodate unguarded elaboration calls from other units
-- in which this same mode is set). We inhibit warnings in this case,
-- since this instantiation is not occurring in elaboration code.
elsif Dynamic_Elaboration_Checks then
Set_C_Scope;
Check_A_Call
(N,
Ent,
Standard_Standard,
Inter_Unit_Only => True,
Generate_Warnings => False);
else
return;
end if;
end Check_Elab_Instantiation;
-------------------------
-- Check_Internal_Call --
-------------------------
procedure Check_Internal_Call
(N : Node_Id;
E : Entity_Id;
Outer_Scope : Entity_Id;
Orig_Ent : Entity_Id)
is
Inst_Case : constant Boolean := Nkind (N) in N_Generic_Instantiation;
begin
-- If not function or procedure call or instantiation, then ignore
-- call (this happens in some error case and rewriting cases)
if Nkind (N) /= N_Function_Call
and then
Nkind (N) /= N_Procedure_Call_Statement
and then
not Inst_Case
then
return;
-- Nothing to do if this is a call or instantiation that has
-- already been found to be a sure ABE
elsif ABE_Is_Certain (N) then
return;
-- Nothing to do if errors already detected (avoid cascaded errors)
elsif Serious_Errors_Detected /= 0 then
return;
-- Nothing to do if not in full analysis mode
elsif not Full_Analysis then
return;
-- Nothing to do if within a default expression, since the call
-- is not actualy being made at this time.
elsif In_Default_Expression then
return;
-- Nothing to do for call to intrinsic subprogram
elsif Is_Intrinsic_Subprogram (E) then
return;
-- No need to trace local calls if checking task activation, because
-- other local bodies are elaborated already.
elsif In_Task_Activation then
return;
end if;
-- Delay this call if we are still delaying calls
if Delaying_Elab_Checks then
Delay_Check.Increment_Last;
Delay_Check.Table (Delay_Check.Last) :=
(N => N,
E => E,
Orig_Ent => Orig_Ent,
Curscop => Current_Scope,
Outer_Scope => Outer_Scope,
From_Elab_Code => From_Elab_Code);
return;
-- Otherwise, call phase 2 continuation right now
else
Check_Internal_Call_Continue (N, E, Outer_Scope, Orig_Ent);
end if;
end Check_Internal_Call;
----------------------------------
-- Check_Internal_Call_Continue --
----------------------------------
procedure Check_Internal_Call_Continue
(N : Node_Id;
E : Entity_Id;
Outer_Scope : Entity_Id;
Orig_Ent : Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
Inst_Case : constant Boolean := Is_Generic_Unit (E);
Sbody : Node_Id;
Ebody : Entity_Id;
function Process (N : Node_Id) return Traverse_Result;
-- Function applied to each node as we traverse the body.
-- Checks for call that needs checking, and if so checks
-- it. Always returns OK, so entire tree is traversed.
-------------
-- Process --
-------------
function Process (N : Node_Id) return Traverse_Result is
begin
-- If user has specified that there are no entry calls in elaboration
-- code, do not trace past an accept statement, because the rendez-
-- vous will happen after elaboration.
if (Nkind (Original_Node (N)) = N_Accept_Statement
or else Nkind (Original_Node (N)) = N_Selective_Accept)
and then Restrictions (No_Entry_Calls_In_Elaboration_Code)
then
return Abandon;
-- If we have a subprogram call, check it
elsif Nkind (N) = N_Function_Call
or else Nkind (N) = N_Procedure_Call_Statement
then
Check_Elab_Call (N, Outer_Scope);
return OK;
-- If we have a generic instantiation, check it
elsif Nkind (N) in N_Generic_Instantiation then
Check_Elab_Instantiation (N, Outer_Scope);
return OK;
-- Skip subprogram bodies that come from source (wait for
-- call to analyze these). The reason for the come from
-- source test is to avoid catching task bodies.
-- For task bodies, we should really avoid these too, waiting
-- for the task activation, but that's too much trouble to
-- catch for now, so we go in unconditionally. This is not
-- so terrible, it means the error backtrace is not quite
-- complete, and we are too eager to scan bodies of tasks
-- that are unused, but this is hardly very significant!
elsif Nkind (N) = N_Subprogram_Body
and then Comes_From_Source (N)
then
return Skip;
else
return OK;
end if;
end Process;
procedure Traverse is new Atree.Traverse_Proc;
-- Traverse procedure using above Process function
-- Start of processing for Check_Internal_Call_Continue
begin
-- Save outer level call if at outer level
if Elab_Call.Last = 0 then
Outer_Level_Sloc := Loc;
end if;
Elab_Visited.Increment_Last;
Elab_Visited.Table (Elab_Visited.Last) := E;
-- If the call is to a function that renames a literal, no check
-- is needed.
if Ekind (E) = E_Enumeration_Literal then
return;
end if;
Sbody := Unit_Declaration_Node (E);
if Nkind (Sbody) /= N_Subprogram_Body
and then
Nkind (Sbody) /= N_Package_Body
then
Ebody := Corresponding_Body (Sbody);
if No (Ebody) then
return;
else
Sbody := Unit_Declaration_Node (Ebody);
end if;
end if;
-- If the body appears after the outer level call or
-- instantiation then we have an error case handled below.
if Earlier_In_Extended_Unit (Outer_Level_Sloc, Sloc (Sbody))
and then not In_Task_Activation
then
null;
-- If we have the instantiation case we are done, since we now
-- know that the body of the generic appeared earlier.
elsif Inst_Case then
return;
-- Otherwise we have a call, so we trace through the called
-- body to see if it has any problems ..
else
pragma Assert (Nkind (Sbody) = N_Subprogram_Body);
Elab_Call.Increment_Last;
Elab_Call.Table (Elab_Call.Last).Cloc := Loc;
Elab_Call.Table (Elab_Call.Last).Ent := E;
if Debug_Flag_LL then
Write_Str ("Elab_Call.Last = ");
Write_Int (Int (Elab_Call.Last));
Write_Str (" Ent = ");
Write_Name (Chars (E));
Write_Str (" at ");
Write_Location (Sloc (N));
Write_Eol;
end if;
-- Now traverse declarations and statements of subprogram body.
-- Note that we cannot simply Traverse (Sbody), since traverse
-- does not normally visit subprogram bodies.
declare
Decl : Node_Id := First (Declarations (Sbody));
begin
while Present (Decl) loop
Traverse (Decl);
Next (Decl);
end loop;
end;
Traverse (Handled_Statement_Sequence (Sbody));
Elab_Call.Decrement_Last;
return;
end if;
-- Here is the case of calling a subprogram where the body has
-- not yet been encountered, a warning message is needed.
-- If we have nothing in the call stack, then this is at the
-- outer level, and the ABE is bound to occur.
if Elab_Call.Last = 0 then
if Inst_Case then
Error_Msg_NE
("?cannot instantiate& before body seen", N, Orig_Ent);
else
Error_Msg_NE
("?cannot call& before body seen", N, Orig_Ent);
end if;
Error_Msg_N
("\?Program_Error will be raised at run time", N);
Insert_Elab_Check (N);
-- Call is not at outer level
else
-- Deal with dynamic elaboration check
if not Elaboration_Checks_Suppressed (E) then
Set_Elaboration_Entity_Required (E);
-- Case of no elaboration entity allocated yet
if No (Elaboration_Entity (E)) then
-- Create object declaration for elaboration entity, and put it
-- just in front of the spec of the subprogram or generic unit,
-- in the same scope as this unit.
declare
Loce : constant Source_Ptr := Sloc (E);
Ent : constant Entity_Id :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (E), 'E'));
begin
Set_Elaboration_Entity (E, Ent);
New_Scope (Scope (E));
Insert_Action (Declaration_Node (E),
Make_Object_Declaration (Loce,
Defining_Identifier => Ent,
Object_Definition =>
New_Occurrence_Of (Standard_Boolean, Loce),
Expression => New_Occurrence_Of (Standard_False, Loce)));
-- Set elaboration flag at the point of the body
Set_Elaboration_Flag (Sbody, E);
-- Kill current value indication. This is necessary
-- because the tests of this flag are inserted out of
-- sequence and must not pick up bogus indications of
-- the wrong constant value. Also, this is never a true
-- constant, since one way or another, it gets reset.
Set_Current_Value (Ent, Empty);
Set_Is_True_Constant (Ent, False);
Pop_Scope;
end;
end if;
-- Generate check of the elaboration Boolean
Insert_Elab_Check (N,
New_Occurrence_Of (Elaboration_Entity (E), Loc));
end if;
-- Generate the warning
if not Suppress_Elaboration_Warnings (E)
and then not Elaboration_Checks_Suppressed (E)
then
if Inst_Case then
Error_Msg_NE
("instantiation of& may occur before body is seen?",
N, Orig_Ent);
else
Error_Msg_NE
("call to& may occur before body is seen?", N, Orig_Ent);
end if;
Error_Msg_N
("\Program_Error may be raised at run time?", N);
Output_Calls (N);
end if;
end if;
-- Set flag to suppress further warnings on same subprogram
-- unless in all errors mode
if not All_Errors_Mode then
Set_Suppress_Elaboration_Warnings (E);
end if;
end Check_Internal_Call_Continue;
---------------------------
-- Check_Task_Activation --
---------------------------
procedure Check_Task_Activation (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Inter_Procs : constant Elist_Id := New_Elmt_List;
Intra_Procs : constant Elist_Id := New_Elmt_List;
Ent : Entity_Id;
P : Entity_Id;
Task_Scope : Entity_Id;
Cunit_SC : Boolean := False;
Decl : Node_Id;
Elmt : Elmt_Id;
Enclosing : Entity_Id;
procedure Add_Task_Proc (Typ : Entity_Id);
-- Add to Task_Procs the task body procedure(s) of task types in Typ.
-- For record types, this procedure recurses over component types.
procedure Collect_Tasks (Decls : List_Id);
-- Collect the types of the tasks that are to be activated in the given
-- list of declarations, in order to perform elaboration checks on the
-- corresponding task procedures which are called implicitly here.
function Outer_Unit (E : Entity_Id) return Entity_Id;
-- find enclosing compilation unit of Entity, ignoring subunits, or
-- else enclosing subprogram. If E is not a package, there is no need
-- for inter-unit elaboration checks.
-------------------
-- Add_Task_Proc --
-------------------
procedure Add_Task_Proc (Typ : Entity_Id) is
Comp : Entity_Id;
Proc : Entity_Id := Empty;
begin
if Is_Task_Type (Typ) then
Proc := Get_Task_Body_Procedure (Typ);
elsif Is_Array_Type (Typ)
and then Has_Task (Base_Type (Typ))
then
Add_Task_Proc (Component_Type (Typ));
elsif Is_Record_Type (Typ)
and then Has_Task (Base_Type (Typ))
then
Comp := First_Component (Typ);
while Present (Comp) loop
Add_Task_Proc (Etype (Comp));
Comp := Next_Component (Comp);
end loop;
end if;
-- If the task type is another unit, we will perform the usual
-- elaboration check on its enclosing unit. If the type is in the
-- same unit, we can trace the task body as for an internal call,
-- but we only need to examine other external calls, because at
-- the point the task is activated, internal subprogram bodies
-- will have been elaborated already. We keep separate lists for
-- each kind of task.
-- Skip this test if errors have occurred, since in this case
-- we can get false indications.
if Serious_Errors_Detected /= 0 then
return;
end if;
if Present (Proc) then
if Outer_Unit (Scope (Proc)) = Enclosing then
if No (Corresponding_Body (Unit_Declaration_Node (Proc)))
and then
(not Is_Generic_Instance (Scope (Proc))
or else
Scope (Proc) = Scope (Defining_Identifier (Decl)))
then
Error_Msg_N
("task will be activated before elaboration of its body?",
Decl);
Error_Msg_N
("Program_Error will be raised at run-time?", Decl);
elsif
Present (Corresponding_Body (Unit_Declaration_Node (Proc)))
then
Append_Elmt (Proc, Intra_Procs);
end if;
else
Elmt := First_Elmt (Inter_Procs);
-- No need for multiple entries of the same type.
while Present (Elmt) loop
if Node (Elmt) = Proc then
return;
end if;
Next_Elmt (Elmt);
end loop;
Append_Elmt (Proc, Inter_Procs);
end if;
end if;
end Add_Task_Proc;
-------------------
-- Collect_Tasks --
-------------------
procedure Collect_Tasks (Decls : List_Id) is
begin
if Present (Decls) then
Decl := First (Decls);
while Present (Decl) loop
if Nkind (Decl) = N_Object_Declaration
and then Has_Task (Etype (Defining_Identifier (Decl)))
then
Add_Task_Proc (Etype (Defining_Identifier (Decl)));
end if;
Next (Decl);
end loop;
end if;
end Collect_Tasks;
----------------
-- Outer_Unit --
----------------
function Outer_Unit (E : Entity_Id) return Entity_Id is
Outer : Entity_Id := E;
begin
while Present (Outer) loop
if Elaboration_Checks_Suppressed (Outer) then
Cunit_SC := True;
end if;
exit when Is_Child_Unit (Outer)
or else Scope (Outer) = Standard_Standard
or else Ekind (Outer) /= E_Package;
Outer := Scope (Outer);
end loop;
return Outer;
end Outer_Unit;
-- Start of processing for Check_Task_Activation
begin
Enclosing := Outer_Unit (Current_Scope);
-- Find all tasks declared in the current unit.
if Nkind (N) = N_Package_Body then
P := Unit_Declaration_Node (Corresponding_Spec (N));
Collect_Tasks (Declarations (N));
Collect_Tasks (Visible_Declarations (Specification (P)));
Collect_Tasks (Private_Declarations (Specification (P)));
elsif Nkind (N) = N_Package_Declaration then
Collect_Tasks (Visible_Declarations (Specification (N)));
Collect_Tasks (Private_Declarations (Specification (N)));
else
Collect_Tasks (Declarations (N));
end if;
-- We only perform detailed checks in all tasks are library level
-- entities. If the master is a subprogram or task, activation will
-- depend on the activation of the master itself.
-- Should dynamic checks be added in the more general case???
if Ekind (Enclosing) /= E_Package then
return;
end if;
-- For task types defined in other units, we want the unit containing
-- the task body to be elaborated before the current one.
Elmt := First_Elmt (Inter_Procs);
while Present (Elmt) loop
Ent := Node (Elmt);
Task_Scope := Outer_Unit (Scope (Ent));
if not Is_Compilation_Unit (Task_Scope) then
null;
elsif Suppress_Elaboration_Warnings (Task_Scope)
or else Elaboration_Checks_Suppressed (Task_Scope)
then
null;
elsif Dynamic_Elaboration_Checks then
if not Elaboration_Checks_Suppressed (Ent)
and then not Cunit_SC
and then not Restrictions (No_Entry_Calls_In_Elaboration_Code)
then
-- Runtime elaboration check required. generate check of the
-- elaboration Boolean for the unit containing the entity.
Insert_Elab_Check (N,
Make_Attribute_Reference (Loc,
Attribute_Name => Name_Elaborated,
Prefix =>
New_Occurrence_Of
(Spec_Entity (Task_Scope), Loc)));
end if;
else
-- Force the binder to elaborate other unit first
if not Suppress_Elaboration_Warnings (Ent)
and then not Elaboration_Checks_Suppressed (Ent)
and then Elab_Warnings
and then not Suppress_Elaboration_Warnings (Task_Scope)
and then not Elaboration_Checks_Suppressed (Task_Scope)
then
Error_Msg_Node_2 := Task_Scope;
Error_Msg_NE ("activation of an instance of task type&" &
" requires pragma Elaborate_All on &?", N, Ent);
end if;
Set_Elaborate_All_Desirable (Task_Scope);
Set_Suppress_Elaboration_Warnings (Task_Scope);
end if;
Next_Elmt (Elmt);
end loop;
-- For tasks declared in the current unit, trace other calls within
-- the task procedure bodies, which are available.
In_Task_Activation := True;
Elmt := First_Elmt (Intra_Procs);
while Present (Elmt) loop
Ent := Node (Elmt);
Check_Internal_Call_Continue (N, Ent, Enclosing, Ent);
Next_Elmt (Elmt);
end loop;
In_Task_Activation := False;
end Check_Task_Activation;
----------------------
-- Has_Generic_Body --
----------------------
function Has_Generic_Body (N : Node_Id) return Boolean is
Ent : constant Entity_Id := Get_Generic_Entity (N);
Decl : constant Node_Id := Unit_Declaration_Node (Ent);
Scop : Entity_Id;
function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id;
-- Determine if the list of nodes headed by N and linked by Next
-- contains a package body for the package spec entity E, and if
-- so return the package body. If not, then returns Empty.
function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id;
-- This procedure is called load the unit whose name is given by Nam.
-- This unit is being loaded to see whether it contains an optional
-- generic body. The returned value is the loaded unit, which is
-- always a package body (only package bodies can contain other
-- entities in the sense in which Has_Generic_Body is interested).
-- We only attempt to load bodies if we are generating code. If we
-- are in semantics check only mode, then it would be wrong to load
-- bodies that are not required from a semantic point of view, so
-- in this case we return Empty. The result is that the caller may
-- incorrectly decide that a generic spec does not have a body when
-- in fact it does, but the only harm in this is that some warnings
-- on elaboration problems may be lost in semantic checks only mode,
-- which is not big loss. We also return Empty if we go for a body
-- and it is not there.
function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id;
-- PE is the entity for a package spec. This function locates the
-- corresponding package body, returning Empty if none is found.
-- The package body returned is fully parsed but may not yet be
-- analyzed, so only syntactic fields should be referenced.
------------------
-- Find_Body_In --
------------------
function Find_Body_In (E : Entity_Id; N : Node_Id) return Node_Id is
Nod : Node_Id;
begin
Nod := N;
while Present (Nod) loop
-- If we found the package body we are looking for, return it
if Nkind (Nod) = N_Package_Body
and then Chars (Defining_Unit_Name (Nod)) = Chars (E)
then
return Nod;
-- If we found the stub for the body, go after the subunit,
-- loading it if necessary.
elsif Nkind (Nod) = N_Package_Body_Stub
and then Chars (Defining_Identifier (Nod)) = Chars (E)
then
if Present (Library_Unit (Nod)) then
return Unit (Library_Unit (Nod));
else
return Load_Package_Body (Get_Unit_Name (Nod));
end if;
-- If neither package body nor stub, keep looking on chain
else
Next (Nod);
end if;
end loop;
return Empty;
end Find_Body_In;
-----------------------
-- Load_Package_Body --
-----------------------
function Load_Package_Body (Nam : Unit_Name_Type) return Node_Id is
U : Unit_Number_Type;
begin
if Operating_Mode /= Generate_Code then
return Empty;
else
U :=
Load_Unit
(Load_Name => Nam,
Required => False,
Subunit => False,
Error_Node => N);
if U = No_Unit then
return Empty;
else
return Unit (Cunit (U));
end if;
end if;
end Load_Package_Body;
-------------------------------
-- Locate_Corresponding_Body --
-------------------------------
function Locate_Corresponding_Body (PE : Entity_Id) return Node_Id is
Spec : constant Node_Id := Declaration_Node (PE);
Decl : constant Node_Id := Parent (Spec);
Scop : constant Entity_Id := Scope (PE);
PBody : Node_Id;
begin
if Is_Library_Level_Entity (PE) then
-- If package is a library unit that requires a body, we have
-- no choice but to go after that body because it might contain
-- an optional body for the original generic package.
if Unit_Requires_Body (PE) then
-- Load the body. Note that we are a little careful here to
-- use Spec to get the unit number, rather than PE or Decl,
-- since in the case where the package is itself a library
-- level instantiation, Spec will properly reference the
-- generic template, which is what we really want.
return
Load_Package_Body
(Get_Body_Name (Unit_Name (Get_Source_Unit (Spec))));
-- But if the package is a library unit that does NOT require
-- a body, then no body is permitted, so we are sure that there
-- is no body for the original generic package.
else
return Empty;
end if;
-- Otherwise look and see if we are embedded in a further package
elsif Is_Package (Scop) then
-- If so, get the body of the enclosing package, and look in
-- its package body for the package body we are looking for.
PBody := Locate_Corresponding_Body (Scop);
if No (PBody) then
return Empty;
else
return Find_Body_In (PE, First (Declarations (PBody)));
end if;
-- If we are not embedded in a further package, then the body
-- must be in the same declarative part as we are.
else
return Find_Body_In (PE, Next (Decl));
end if;
end Locate_Corresponding_Body;
-- Start of processing for Has_Generic_Body
begin
if Present (Corresponding_Body (Decl)) then
return True;
elsif Unit_Requires_Body (Ent) then
return True;
-- Compilation units cannot have optional bodies
elsif Is_Compilation_Unit (Ent) then
return False;
-- Otherwise look at what scope we are in
else
Scop := Scope (Ent);
-- Case of entity is in other than a package spec, in this case
-- the body, if present, must be in the same declarative part.
if not Is_Package (Scop) then
declare
P : Node_Id;
begin
P := Declaration_Node (Ent);
-- Declaration node may get us a spec, so if so, go to
-- the parent declaration.
while not Is_List_Member (P) loop
P := Parent (P);
end loop;
return Present (Find_Body_In (Ent, Next (P)));
end;
-- If the entity is in a package spec, then we have to locate
-- the corresponding package body, and look there.
else
declare
PBody : constant Node_Id := Locate_Corresponding_Body (Scop);
begin
if No (PBody) then
return False;
else
return
Present
(Find_Body_In (Ent, (First (Declarations (PBody)))));
end if;
end;
end if;
end if;
end Has_Generic_Body;
-----------------------
-- Insert_Elab_Check --
-----------------------
procedure Insert_Elab_Check (N : Node_Id; C : Node_Id := Empty) is
Nod : Node_Id;
Loc : constant Source_Ptr := Sloc (N);
begin
-- If expansion is disabled, do not generate any checks. Also
-- skip checks if any subunits are missing because in either
-- case we lack the full information that we need, and no object
-- file will be created in any case.
if not Expander_Active or else Subunits_Missing then
return;
end if;
-- If we have a generic instantiation, where Instance_Spec is set,
-- then this field points to a generic instance spec that has
-- been inserted before the instantiation node itself, so that
-- is where we want to insert a check.
if Nkind (N) in N_Generic_Instantiation
and then Present (Instance_Spec (N))
then
Nod := Instance_Spec (N);
else
Nod := N;
end if;
-- If we are inserting at the top level, insert in Aux_Decls
if Nkind (Parent (Nod)) = N_Compilation_Unit then
declare
ADN : constant Node_Id := Aux_Decls_Node (Parent (Nod));
R : Node_Id;
begin
if No (C) then
R :=
Make_Raise_Program_Error (Loc,
Reason => PE_Access_Before_Elaboration);
else
R :=
Make_Raise_Program_Error (Loc,
Condition => Make_Op_Not (Loc, C),
Reason => PE_Access_Before_Elaboration);
end if;
if No (Declarations (ADN)) then
Set_Declarations (ADN, New_List (R));
else
Append_To (Declarations (ADN), R);
end if;
Analyze (R);
end;
-- Otherwise just insert before the node in question. However, if
-- the context of the call has already been analyzed, an insertion
-- will not work if it depends on subsequent expansion (e.g. a call in
-- a branch of a short-circuit). In that case we replace the call with
-- a conditional expression, or with a Raise if it is unconditional.
-- Unfortunately this does not work if the call has a dynamic size,
-- because gigi regards it as a dynamic-sized temporary. If such a call
-- appears in a short-circuit expression, the elaboration check will be
-- missed (rare enough ???). Otherwise, the code below inserts the check
-- at the appropriate place before the call. Same applies in the even
-- rarer case the return type has a known size but is unconstrained.
else
if Nkind (N) = N_Function_Call
and then Analyzed (Parent (N))
and then Size_Known_At_Compile_Time (Etype (N))
and then
(not Has_Discriminants (Etype (N))
or else Is_Constrained (Etype (N)))
then
declare
Typ : constant Entity_Id := Etype (N);
Chk : constant Boolean := Do_Range_Check (N);
R : constant Node_Id :=
Make_Raise_Program_Error (Loc,
Reason => PE_Access_Before_Elaboration);
begin
Set_Etype (R, Typ);
if No (C) then
Rewrite (N, R);
else
Rewrite (N,
Make_Conditional_Expression (Loc,
Expressions => New_List (C, Relocate_Node (N), R)));
end if;
Analyze_And_Resolve (N, Typ);
-- If the original call requires a range check, so does the
-- conditional expression.
if Chk then
Enable_Range_Check (N);
else
Set_Do_Range_Check (N, False);
end if;
end;
else
if No (C) then
Insert_Action (Nod,
Make_Raise_Program_Error (Loc,
Reason => PE_Access_Before_Elaboration));
else
Insert_Action (Nod,
Make_Raise_Program_Error (Loc,
Condition =>
Make_Op_Not (Loc,
Right_Opnd => C),
Reason => PE_Access_Before_Elaboration));
end if;
end if;
end if;
end Insert_Elab_Check;
------------------
-- Output_Calls --
------------------
procedure Output_Calls (N : Node_Id) is
Ent : Entity_Id;
function Is_Printable_Error_Name (Nm : Name_Id) return Boolean;
-- An internal function, used to determine if a name, Nm, is either
-- a non-internal name, or is an internal name that is printable
-- by the error message circuits (i.e. it has a single upper
-- case letter at the end).
function Is_Printable_Error_Name (Nm : Name_Id) return Boolean is
begin
if not Is_Internal_Name (Nm) then
return True;
elsif Name_Len = 1 then
return False;
else
Name_Len := Name_Len - 1;
return not Is_Internal_Name;
end if;
end Is_Printable_Error_Name;
-- Start of processing for Output_Calls
begin
for J in reverse 1 .. Elab_Call.Last loop
Error_Msg_Sloc := Elab_Call.Table (J).Cloc;
Ent := Elab_Call.Table (J).Ent;
if Is_Generic_Unit (Ent) then
Error_Msg_NE ("\?& instantiated #", N, Ent);
elsif Is_Init_Proc (Ent) then
Error_Msg_N ("\?initialization procedure called #", N);
elsif Is_Printable_Error_Name (Chars (Ent)) then
Error_Msg_NE ("\?& called #", N, Ent);
else
Error_Msg_N ("\? called #", N);
end if;
end loop;
end Output_Calls;
----------------------------
-- Same_Elaboration_Scope --
----------------------------
function Same_Elaboration_Scope (Scop1, Scop2 : Entity_Id) return Boolean is
S1 : Entity_Id := Scop1;
S2 : Entity_Id := Scop2;
begin
while S1 /= Standard_Standard
and then (Ekind (S1) = E_Package
or else
Ekind (S1) = E_Block)
loop
S1 := Scope (S1);
end loop;
while S2 /= Standard_Standard
and then (Ekind (S2) = E_Package
or else
Ekind (S2) = E_Protected_Type
or else
Ekind (S2) = E_Block)
loop
S2 := Scope (S2);
end loop;
return S1 = S2;
end Same_Elaboration_Scope;
-----------------
-- Set_C_Scope --
-----------------
procedure Set_C_Scope is
begin
while not Is_Compilation_Unit (C_Scope) loop
C_Scope := Scope (C_Scope);
end loop;
end Set_C_Scope;
-----------------
-- Spec_Entity --
-----------------
function Spec_Entity (E : Entity_Id) return Entity_Id is
Decl : Node_Id;
begin
-- Check for case of body entity
-- Why is the check for E_Void needed???
if Ekind (E) = E_Void
or else Ekind (E) = E_Subprogram_Body
or else Ekind (E) = E_Package_Body
then
Decl := E;
loop
Decl := Parent (Decl);
exit when Nkind (Decl) in N_Proper_Body;
end loop;
return Corresponding_Spec (Decl);
else
return E;
end if;
end Spec_Entity;
-------------------
-- Supply_Bodies --
-------------------
procedure Supply_Bodies (N : Node_Id) is
begin
if Nkind (N) = N_Subprogram_Declaration then
declare
Ent : constant Entity_Id := Defining_Unit_Name (Specification (N));
begin
Set_Is_Imported (Ent);
Set_Convention (Ent, Convention_Stubbed);
end;
elsif Nkind (N) = N_Package_Declaration then
declare
Spec : constant Node_Id := Specification (N);
begin
New_Scope (Defining_Unit_Name (Spec));
Supply_Bodies (Visible_Declarations (Spec));
Supply_Bodies (Private_Declarations (Spec));
Pop_Scope;
end;
end if;
end Supply_Bodies;
procedure Supply_Bodies (L : List_Id) is
Elmt : Node_Id;
begin
if Present (L) then
Elmt := First (L);
while Present (Elmt) loop
Supply_Bodies (Elmt);
Next (Elmt);
end loop;
end if;
end Supply_Bodies;
------------
-- Within --
------------
function Within (E1, E2 : Entity_Id) return Boolean is
Scop : Entity_Id;
begin
Scop := E1;
loop
if Scop = E2 then
return True;
elsif Scop = Standard_Standard then
return False;
else
Scop := Scope (Scop);
end if;
end loop;
raise Program_Error;
end Within;
--------------------------
-- Within_Elaborate_All --
--------------------------
function Within_Elaborate_All (E : Entity_Id) return Boolean is
Item : Node_Id;
Item2 : Node_Id;
Elab_Id : Entity_Id;
Par : Node_Id;
begin
Item := First (Context_Items (Cunit (Current_Sem_Unit)));
while Present (Item) loop
if Nkind (Item) = N_Pragma
and then Get_Pragma_Id (Chars (Item)) = Pragma_Elaborate_All
then
if Error_Posted (Item) then
-- Some previous error on the pragma itself
return False;
end if;
Elab_Id :=
Entity (
Expression (First (Pragma_Argument_Associations (Item))));
Par := Parent (Unit_Declaration_Node (Elab_Id));
Item2 := First (Context_Items (Par));
while Present (Item2) loop
if Nkind (Item2) = N_With_Clause
and then Entity (Name (Item2)) = E
then
return True;
end if;
Next (Item2);
end loop;
end if;
Next (Item);
end loop;
return False;
end Within_Elaborate_All;
end Sem_Elab;