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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ A G G R --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, 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 Aspects; use Aspects;
with Atree; use Atree;
with Checks; use Checks;
with Einfo; use Einfo;
with Elists; use Elists;
with Errout; use Errout;
with Expander; use Expander;
with Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Freeze; use Freeze;
with Itypes; use Itypes;
with Lib; use Lib;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Namet.Sp; use Namet.Sp;
with Nmake; use Nmake;
with Nlists; use Nlists;
with Opt; use Opt;
with Restrict; use Restrict;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch8; use Sem_Ch8;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Type; use Sem_Type;
with Sem_Warn; use Sem_Warn;
with Sinfo; use Sinfo;
with Snames; use Snames;
with Stringt; use Stringt;
with Stand; use Stand;
with Style; use Style;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Aggr is
type Case_Bounds is record
Lo : Node_Id;
-- Low bound of choice. Once we sort the Case_Table, then entries
-- will be in order of ascending Choice_Lo values.
Hi : Node_Id;
-- High Bound of choice. The sort does not pay any attention to the
-- high bound, so choices 1 .. 4 and 1 .. 5 could be in either order.
Highest : Uint;
-- If there are duplicates or missing entries, then in the sorted
-- table, this records the highest value among Choice_Hi values
-- seen so far, including this entry.
Choice : Node_Id;
-- The node of the choice
end record;
type Case_Table_Type is array (Nat range <>) of Case_Bounds;
-- Table type used by Check_Case_Choices procedure. Entry zero is not
-- used (reserved for the sort). Real entries start at one.
-----------------------
-- Local Subprograms --
-----------------------
procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
-- Sort the Case Table using the Lower Bound of each Choice as the key. A
-- simple insertion sort is used since the choices in a case statement will
-- usually be in near sorted order.
procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id);
-- Ada 2005 (AI-231): Check bad usage of null for a component for which
-- null exclusion (NOT NULL) is specified. Typ can be an E_Array_Type for
-- the array case (the component type of the array will be used) or an
-- E_Component/E_Discriminant entity in the record case, in which case the
-- type of the component will be used for the test. If Typ is any other
-- kind of entity, the call is ignored. Expr is the component node in the
-- aggregate which is known to have a null value. A warning message will be
-- issued if the component is null excluding.
--
-- It would be better to pass the proper type for Typ ???
procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id);
-- Check that Expr is either not limited or else is one of the cases of
-- expressions allowed for a limited component association (namely, an
-- aggregate, function call, or <> notation). Report error for violations.
-- Expression is also OK in an instance or inlining context, because we
-- have already pre-analyzed and it is known to be type correct.
procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id);
-- Given aggregate Expr, check that sub-aggregates of Expr that are nested
-- at Level are qualified. If Level = 0, this applies to Expr directly.
-- Only issue errors in formal verification mode.
function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean;
-- Return True of Expr is an aggregate not contained directly in another
-- aggregate.
------------------------------------------------------
-- Subprograms used for RECORD AGGREGATE Processing --
------------------------------------------------------
procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id);
-- This procedure performs all the semantic checks required for record
-- aggregates. Note that for aggregates analysis and resolution go
-- hand in hand. Aggregate analysis has been delayed up to here and
-- it is done while resolving the aggregate.
--
-- N is the N_Aggregate node.
-- Typ is the record type for the aggregate resolution
--
-- While performing the semantic checks, this procedure builds a new
-- Component_Association_List where each record field appears alone in a
-- Component_Choice_List along with its corresponding expression. The
-- record fields in the Component_Association_List appear in the same order
-- in which they appear in the record type Typ.
--
-- Once this new Component_Association_List is built and all the semantic
-- checks performed, the original aggregate subtree is replaced with the
-- new named record aggregate just built. Note that subtree substitution is
-- performed with Rewrite so as to be able to retrieve the original
-- aggregate.
--
-- The aggregate subtree manipulation performed by Resolve_Record_Aggregate
-- yields the aggregate format expected by Gigi. Typically, this kind of
-- tree manipulations are done in the expander. However, because the
-- semantic checks that need to be performed on record aggregates really go
-- hand in hand with the record aggregate normalization, the aggregate
-- subtree transformation is performed during resolution rather than
-- expansion. Had we decided otherwise we would have had to duplicate most
-- of the code in the expansion procedure Expand_Record_Aggregate. Note,
-- however, that all the expansion concerning aggregates for tagged records
-- is done in Expand_Record_Aggregate.
--
-- The algorithm of Resolve_Record_Aggregate proceeds as follows:
--
-- 1. Make sure that the record type against which the record aggregate
-- has to be resolved is not abstract. Furthermore if the type is a
-- null aggregate make sure the input aggregate N is also null.
--
-- 2. Verify that the structure of the aggregate is that of a record
-- aggregate. Specifically, look for component associations and ensure
-- that each choice list only has identifiers or the N_Others_Choice
-- node. Also make sure that if present, the N_Others_Choice occurs
-- last and by itself.
--
-- 3. If Typ contains discriminants, the values for each discriminant is
-- looked for. If the record type Typ has variants, we check that the
-- expressions corresponding to each discriminant ruling the (possibly
-- nested) variant parts of Typ, are static. This allows us to determine
-- the variant parts to which the rest of the aggregate must conform.
-- The names of discriminants with their values are saved in a new
-- association list, New_Assoc_List which is later augmented with the
-- names and values of the remaining components in the record type.
--
-- During this phase we also make sure that every discriminant is
-- assigned exactly one value. Note that when several values for a given
-- discriminant are found, semantic processing continues looking for
-- further errors. In this case it's the first discriminant value found
-- which we will be recorded.
--
-- IMPORTANT NOTE: For derived tagged types this procedure expects
-- First_Discriminant and Next_Discriminant to give the correct list
-- of discriminants, in the correct order.
--
-- 4. After all the discriminant values have been gathered, we can set the
-- Etype of the record aggregate. If Typ contains no discriminants this
-- is straightforward: the Etype of N is just Typ, otherwise a new
-- implicit constrained subtype of Typ is built to be the Etype of N.
--
-- 5. Gather the remaining record components according to the discriminant
-- values. This involves recursively traversing the record type
-- structure to see what variants are selected by the given discriminant
-- values. This processing is a little more convoluted if Typ is a
-- derived tagged types since we need to retrieve the record structure
-- of all the ancestors of Typ.
--
-- 6. After gathering the record components we look for their values in the
-- record aggregate and emit appropriate error messages should we not
-- find such values or should they be duplicated.
--
-- 7. We then make sure no illegal component names appear in the record
-- aggregate and make sure that the type of the record components
-- appearing in a same choice list is the same. Finally we ensure that
-- the others choice, if present, is used to provide the value of at
-- least a record component.
--
-- 8. The original aggregate node is replaced with the new named aggregate
-- built in steps 3 through 6, as explained earlier.
--
-- Given the complexity of record aggregate resolution, the primary goal of
-- this routine is clarity and simplicity rather than execution and storage
-- efficiency. If there are only positional components in the aggregate the
-- running time is linear. If there are associations the running time is
-- still linear as long as the order of the associations is not too far off
-- the order of the components in the record type. If this is not the case
-- the running time is at worst quadratic in the size of the association
-- list.
procedure Check_Misspelled_Component
(Elements : Elist_Id;
Component : Node_Id);
-- Give possible misspelling diagnostic if Component is likely to be a
-- misspelling of one of the components of the Assoc_List. This is called
-- by Resolve_Aggr_Expr after producing an invalid component error message.
procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id);
-- An optimization: determine whether a discriminated subtype has a static
-- constraint, and contains array components whose length is also static,
-- either because they are constrained by the discriminant, or because the
-- original component bounds are static.
-----------------------------------------------------
-- Subprograms used for ARRAY AGGREGATE Processing --
-----------------------------------------------------
function Resolve_Array_Aggregate
(N : Node_Id;
Index : Node_Id;
Index_Constr : Node_Id;
Component_Typ : Entity_Id;
Others_Allowed : Boolean) return Boolean;
-- This procedure performs the semantic checks for an array aggregate.
-- True is returned if the aggregate resolution succeeds.
--
-- The procedure works by recursively checking each nested aggregate.
-- Specifically, after checking a sub-aggregate nested at the i-th level
-- we recursively check all the subaggregates at the i+1-st level (if any).
-- Note that for aggregates analysis and resolution go hand in hand.
-- Aggregate analysis has been delayed up to here and it is done while
-- resolving the aggregate.
--
-- N is the current N_Aggregate node to be checked.
--
-- Index is the index node corresponding to the array sub-aggregate that
-- we are currently checking (RM 4.3.3 (8)). Its Etype is the
-- corresponding index type (or subtype).
--
-- Index_Constr is the node giving the applicable index constraint if
-- any (RM 4.3.3 (10)). It "is a constraint provided by certain
-- contexts [...] that can be used to determine the bounds of the array
-- value specified by the aggregate". If Others_Allowed below is False
-- there is no applicable index constraint and this node is set to Index.
--
-- Component_Typ is the array component type.
--
-- Others_Allowed indicates whether an others choice is allowed
-- in the context where the top-level aggregate appeared.
--
-- The algorithm of Resolve_Array_Aggregate proceeds as follows:
--
-- 1. Make sure that the others choice, if present, is by itself and
-- appears last in the sub-aggregate. Check that we do not have
-- positional and named components in the array sub-aggregate (unless
-- the named association is an others choice). Finally if an others
-- choice is present, make sure it is allowed in the aggregate context.
--
-- 2. If the array sub-aggregate contains discrete_choices:
--
-- (A) Verify their validity. Specifically verify that:
--
-- (a) If a null range is present it must be the only possible
-- choice in the array aggregate.
--
-- (b) Ditto for a non static range.
--
-- (c) Ditto for a non static expression.
--
-- In addition this step analyzes and resolves each discrete_choice,
-- making sure that its type is the type of the corresponding Index.
-- If we are not at the lowest array aggregate level (in the case of
-- multi-dimensional aggregates) then invoke Resolve_Array_Aggregate
-- recursively on each component expression. Otherwise, resolve the
-- bottom level component expressions against the expected component
-- type ONLY IF the component corresponds to a single discrete choice
-- which is not an others choice (to see why read the DELAYED
-- COMPONENT RESOLUTION below).
--
-- (B) Determine the bounds of the sub-aggregate and lowest and
-- highest choice values.
--
-- 3. For positional aggregates:
--
-- (A) Loop over the component expressions either recursively invoking
-- Resolve_Array_Aggregate on each of these for multi-dimensional
-- array aggregates or resolving the bottom level component
-- expressions against the expected component type.
--
-- (B) Determine the bounds of the positional sub-aggregates.
--
-- 4. Try to determine statically whether the evaluation of the array
-- sub-aggregate raises Constraint_Error. If yes emit proper
-- warnings. The precise checks are the following:
--
-- (A) Check that the index range defined by aggregate bounds is
-- compatible with corresponding index subtype.
-- We also check against the base type. In fact it could be that
-- Low/High bounds of the base type are static whereas those of
-- the index subtype are not. Thus if we can statically catch
-- a problem with respect to the base type we are guaranteed
-- that the same problem will arise with the index subtype
--
-- (B) If we are dealing with a named aggregate containing an others
-- choice and at least one discrete choice then make sure the range
-- specified by the discrete choices does not overflow the
-- aggregate bounds. We also check against the index type and base
-- type bounds for the same reasons given in (A).
--
-- (C) If we are dealing with a positional aggregate with an others
-- choice make sure the number of positional elements specified
-- does not overflow the aggregate bounds. We also check against
-- the index type and base type bounds as mentioned in (A).
--
-- Finally construct an N_Range node giving the sub-aggregate bounds.
-- Set the Aggregate_Bounds field of the sub-aggregate to be this
-- N_Range. The routine Array_Aggr_Subtype below uses such N_Ranges
-- to build the appropriate aggregate subtype. Aggregate_Bounds
-- information is needed during expansion.
--
-- DELAYED COMPONENT RESOLUTION: The resolution of bottom level component
-- expressions in an array aggregate may call Duplicate_Subexpr or some
-- other routine that inserts code just outside the outermost aggregate.
-- If the array aggregate contains discrete choices or an others choice,
-- this may be wrong. Consider for instance the following example.
--
-- type Rec is record
-- V : Integer := 0;
-- end record;
--
-- type Acc_Rec is access Rec;
-- Arr : array (1..3) of Acc_Rec := (1 .. 3 => new Rec);
--
-- Then the transformation of "new Rec" that occurs during resolution
-- entails the following code modifications
--
-- P7b : constant Acc_Rec := new Rec;
-- RecIP (P7b.all);
-- Arr : array (1..3) of Acc_Rec := (1 .. 3 => P7b);
--
-- This code transformation is clearly wrong, since we need to call
-- "new Rec" for each of the 3 array elements. To avoid this problem we
-- delay resolution of the components of non positional array aggregates
-- to the expansion phase. As an optimization, if the discrete choice
-- specifies a single value we do not delay resolution.
function Array_Aggr_Subtype (N : Node_Id; Typ : Node_Id) return Entity_Id;
-- This routine returns the type or subtype of an array aggregate.
--
-- N is the array aggregate node whose type we return.
--
-- Typ is the context type in which N occurs.
--
-- This routine creates an implicit array subtype whose bounds are
-- those defined by the aggregate. When this routine is invoked
-- Resolve_Array_Aggregate has already processed aggregate N. Thus the
-- Aggregate_Bounds of each sub-aggregate, is an N_Range node giving the
-- sub-aggregate bounds. When building the aggregate itype, this function
-- traverses the array aggregate N collecting such Aggregate_Bounds and
-- constructs the proper array aggregate itype.
--
-- Note that in the case of multidimensional aggregates each inner
-- sub-aggregate corresponding to a given array dimension, may provide a
-- different bounds. If it is possible to determine statically that
-- some sub-aggregates corresponding to the same index do not have the
-- same bounds, then a warning is emitted. If such check is not possible
-- statically (because some sub-aggregate bounds are dynamic expressions)
-- then this job is left to the expander. In all cases the particular
-- bounds that this function will chose for a given dimension is the first
-- N_Range node for a sub-aggregate corresponding to that dimension.
--
-- Note that the Raises_Constraint_Error flag of an array aggregate
-- whose evaluation is determined to raise CE by Resolve_Array_Aggregate,
-- is set in Resolve_Array_Aggregate but the aggregate is not
-- immediately replaced with a raise CE. In fact, Array_Aggr_Subtype must
-- first construct the proper itype for the aggregate (Gigi needs
-- this). After constructing the proper itype we will eventually replace
-- the top-level aggregate with a raise CE (done in Resolve_Aggregate).
-- Of course in cases such as:
--
-- type Arr is array (integer range <>) of Integer;
-- A : Arr := (positive range -1 .. 2 => 0);
--
-- The bounds of the aggregate itype are cooked up to look reasonable
-- (in this particular case the bounds will be 1 .. 2).
procedure Make_String_Into_Aggregate (N : Node_Id);
-- A string literal can appear in a context in which a one dimensional
-- array of characters is expected. This procedure simply rewrites the
-- string as an aggregate, prior to resolution.
------------------------
-- Array_Aggr_Subtype --
------------------------
function Array_Aggr_Subtype
(N : Node_Id;
Typ : Entity_Id) return Entity_Id
is
Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
-- Number of aggregate index dimensions
Aggr_Range : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
-- Constrained N_Range of each index dimension in our aggregate itype
Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
Aggr_High : array (1 .. Aggr_Dimension) of Node_Id := (others => Empty);
-- Low and High bounds for each index dimension in our aggregate itype
Is_Fully_Positional : Boolean := True;
procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos);
-- N is an array (sub-)aggregate. Dim is the dimension corresponding
-- to (sub-)aggregate N. This procedure collects and removes the side
-- effects of the constrained N_Range nodes corresponding to each index
-- dimension of our aggregate itype. These N_Range nodes are collected
-- in Aggr_Range above.
--
-- Likewise collect in Aggr_Low & Aggr_High above the low and high
-- bounds of each index dimension. If, when collecting, two bounds
-- corresponding to the same dimension are static and found to differ,
-- then emit a warning, and mark N as raising Constraint_Error.
-------------------------
-- Collect_Aggr_Bounds --
-------------------------
procedure Collect_Aggr_Bounds (N : Node_Id; Dim : Pos) is
This_Range : constant Node_Id := Aggregate_Bounds (N);
-- The aggregate range node of this specific sub-aggregate
This_Low : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
This_High : constant Node_Id := High_Bound (Aggregate_Bounds (N));
-- The aggregate bounds of this specific sub-aggregate
Assoc : Node_Id;
Expr : Node_Id;
begin
Remove_Side_Effects (This_Low, Variable_Ref => True);
Remove_Side_Effects (This_High, Variable_Ref => True);
-- Collect the first N_Range for a given dimension that you find.
-- For a given dimension they must be all equal anyway.
if No (Aggr_Range (Dim)) then
Aggr_Low (Dim) := This_Low;
Aggr_High (Dim) := This_High;
Aggr_Range (Dim) := This_Range;
else
if Compile_Time_Known_Value (This_Low) then
if not Compile_Time_Known_Value (Aggr_Low (Dim)) then
Aggr_Low (Dim) := This_Low;
elsif Expr_Value (This_Low) /= Expr_Value (Aggr_Low (Dim)) then
Set_Raises_Constraint_Error (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("sub-aggregate low bound mismatch<<", N);
Error_Msg_N ("\Constraint_Error [<<", N);
end if;
end if;
if Compile_Time_Known_Value (This_High) then
if not Compile_Time_Known_Value (Aggr_High (Dim)) then
Aggr_High (Dim) := This_High;
elsif
Expr_Value (This_High) /= Expr_Value (Aggr_High (Dim))
then
Set_Raises_Constraint_Error (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("sub-aggregate high bound mismatch<<", N);
Error_Msg_N ("\Constraint_Error [<<", N);
end if;
end if;
end if;
if Dim < Aggr_Dimension then
-- Process positional components
if Present (Expressions (N)) then
Expr := First (Expressions (N));
while Present (Expr) loop
Collect_Aggr_Bounds (Expr, Dim + 1);
Next (Expr);
end loop;
end if;
-- Process component associations
if Present (Component_Associations (N)) then
Is_Fully_Positional := False;
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Expr := Expression (Assoc);
Collect_Aggr_Bounds (Expr, Dim + 1);
Next (Assoc);
end loop;
end if;
end if;
end Collect_Aggr_Bounds;
-- Array_Aggr_Subtype variables
Itype : Entity_Id;
-- The final itype of the overall aggregate
Index_Constraints : constant List_Id := New_List;
-- The list of index constraints of the aggregate itype
-- Start of processing for Array_Aggr_Subtype
begin
-- Make sure that the list of index constraints is properly attached to
-- the tree, and then collect the aggregate bounds.
Set_Parent (Index_Constraints, N);
Collect_Aggr_Bounds (N, 1);
-- Build the list of constrained indexes of our aggregate itype
for J in 1 .. Aggr_Dimension loop
Create_Index : declare
Index_Base : constant Entity_Id :=
Base_Type (Etype (Aggr_Range (J)));
Index_Typ : Entity_Id;
begin
-- Construct the Index subtype, and associate it with the range
-- construct that generates it.
Index_Typ :=
Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J));
Set_Etype (Index_Typ, Index_Base);
if Is_Character_Type (Index_Base) then
Set_Is_Character_Type (Index_Typ);
end if;
Set_Size_Info (Index_Typ, (Index_Base));
Set_RM_Size (Index_Typ, RM_Size (Index_Base));
Set_First_Rep_Item (Index_Typ, First_Rep_Item (Index_Base));
Set_Scalar_Range (Index_Typ, Aggr_Range (J));
if Is_Discrete_Or_Fixed_Point_Type (Index_Typ) then
Set_RM_Size (Index_Typ, UI_From_Int (Minimum_Size (Index_Typ)));
end if;
Set_Etype (Aggr_Range (J), Index_Typ);
Append (Aggr_Range (J), To => Index_Constraints);
end Create_Index;
end loop;
-- Now build the Itype
Itype := Create_Itype (E_Array_Subtype, N);
Set_First_Rep_Item (Itype, First_Rep_Item (Typ));
Set_Convention (Itype, Convention (Typ));
Set_Depends_On_Private (Itype, Has_Private_Component (Typ));
Set_Etype (Itype, Base_Type (Typ));
Set_Has_Alignment_Clause (Itype, Has_Alignment_Clause (Typ));
Set_Is_Aliased (Itype, Is_Aliased (Typ));
Set_Depends_On_Private (Itype, Depends_On_Private (Typ));
Copy_Suppress_Status (Index_Check, Typ, Itype);
Copy_Suppress_Status (Length_Check, Typ, Itype);
Set_First_Index (Itype, First (Index_Constraints));
Set_Is_Constrained (Itype, True);
Set_Is_Internal (Itype, True);
-- A simple optimization: purely positional aggregates of static
-- components should be passed to gigi unexpanded whenever possible, and
-- regardless of the staticness of the bounds themselves. Subsequent
-- checks in exp_aggr verify that type is not packed, etc.
Set_Size_Known_At_Compile_Time
(Itype,
Is_Fully_Positional
and then Comes_From_Source (N)
and then Size_Known_At_Compile_Time (Component_Type (Typ)));
-- We always need a freeze node for a packed array subtype, so that we
-- can build the Packed_Array_Impl_Type corresponding to the subtype. If
-- expansion is disabled, the packed array subtype is not built, and we
-- must not generate a freeze node for the type, or else it will appear
-- incomplete to gigi.
if Is_Packed (Itype)
and then not In_Spec_Expression
and then Expander_Active
then
Freeze_Itype (Itype, N);
end if;
return Itype;
end Array_Aggr_Subtype;
--------------------------------
-- Check_Misspelled_Component --
--------------------------------
procedure Check_Misspelled_Component
(Elements : Elist_Id;
Component : Node_Id)
is
Max_Suggestions : constant := 2;
Nr_Of_Suggestions : Natural := 0;
Suggestion_1 : Entity_Id := Empty;
Suggestion_2 : Entity_Id := Empty;
Component_Elmt : Elmt_Id;
begin
-- All the components of List are matched against Component and a count
-- is maintained of possible misspellings. When at the end of the the
-- analysis there are one or two (not more) possible misspellings,
-- these misspellings will be suggested as possible correction.
Component_Elmt := First_Elmt (Elements);
while Nr_Of_Suggestions <= Max_Suggestions
and then Present (Component_Elmt)
loop
if Is_Bad_Spelling_Of
(Chars (Node (Component_Elmt)),
Chars (Component))
then
Nr_Of_Suggestions := Nr_Of_Suggestions + 1;
case Nr_Of_Suggestions is
when 1 => Suggestion_1 := Node (Component_Elmt);
when 2 => Suggestion_2 := Node (Component_Elmt);
when others => exit;
end case;
end if;
Next_Elmt (Component_Elmt);
end loop;
-- Report at most two suggestions
if Nr_Of_Suggestions = 1 then
Error_Msg_NE -- CODEFIX
("\possible misspelling of&", Component, Suggestion_1);
elsif Nr_Of_Suggestions = 2 then
Error_Msg_Node_2 := Suggestion_2;
Error_Msg_NE -- CODEFIX
("\possible misspelling of& or&", Component, Suggestion_1);
end if;
end Check_Misspelled_Component;
----------------------------------------
-- Check_Expr_OK_In_Limited_Aggregate --
----------------------------------------
procedure Check_Expr_OK_In_Limited_Aggregate (Expr : Node_Id) is
begin
if Is_Limited_Type (Etype (Expr))
and then Comes_From_Source (Expr)
then
if In_Instance_Body or else In_Inlined_Body then
null;
elsif not OK_For_Limited_Init (Etype (Expr), Expr) then
Error_Msg_N
("initialization not allowed for limited types", Expr);
Explain_Limited_Type (Etype (Expr), Expr);
end if;
end if;
end Check_Expr_OK_In_Limited_Aggregate;
-------------------------------
-- Check_Qualified_Aggregate --
-------------------------------
procedure Check_Qualified_Aggregate (Level : Nat; Expr : Node_Id) is
Comp_Expr : Node_Id;
Comp_Assn : Node_Id;
begin
if Level = 0 then
if Nkind (Parent (Expr)) /= N_Qualified_Expression then
Check_SPARK_05_Restriction ("aggregate should be qualified", Expr);
end if;
else
Comp_Expr := First (Expressions (Expr));
while Present (Comp_Expr) loop
if Nkind (Comp_Expr) = N_Aggregate then
Check_Qualified_Aggregate (Level - 1, Comp_Expr);
end if;
Comp_Expr := Next (Comp_Expr);
end loop;
Comp_Assn := First (Component_Associations (Expr));
while Present (Comp_Assn) loop
Comp_Expr := Expression (Comp_Assn);
if Nkind (Comp_Expr) = N_Aggregate then
Check_Qualified_Aggregate (Level - 1, Comp_Expr);
end if;
Comp_Assn := Next (Comp_Assn);
end loop;
end if;
end Check_Qualified_Aggregate;
----------------------------------------
-- Check_Static_Discriminated_Subtype --
----------------------------------------
procedure Check_Static_Discriminated_Subtype (T : Entity_Id; V : Node_Id) is
Disc : constant Entity_Id := First_Discriminant (T);
Comp : Entity_Id;
Ind : Entity_Id;
begin
if Has_Record_Rep_Clause (T) then
return;
elsif Present (Next_Discriminant (Disc)) then
return;
elsif Nkind (V) /= N_Integer_Literal then
return;
end if;
Comp := First_Component (T);
while Present (Comp) loop
if Is_Scalar_Type (Etype (Comp)) then
null;
elsif Is_Private_Type (Etype (Comp))
and then Present (Full_View (Etype (Comp)))
and then Is_Scalar_Type (Full_View (Etype (Comp)))
then
null;
elsif Is_Array_Type (Etype (Comp)) then
if Is_Bit_Packed_Array (Etype (Comp)) then
return;
end if;
Ind := First_Index (Etype (Comp));
while Present (Ind) loop
if Nkind (Ind) /= N_Range
or else Nkind (Low_Bound (Ind)) /= N_Integer_Literal
or else Nkind (High_Bound (Ind)) /= N_Integer_Literal
then
return;
end if;
Next_Index (Ind);
end loop;
else
return;
end if;
Next_Component (Comp);
end loop;
-- On exit, all components have statically known sizes
Set_Size_Known_At_Compile_Time (T);
end Check_Static_Discriminated_Subtype;
-------------------------
-- Is_Others_Aggregate --
-------------------------
function Is_Others_Aggregate (Aggr : Node_Id) return Boolean is
begin
return No (Expressions (Aggr))
and then
Nkind (First (Choices (First (Component_Associations (Aggr))))) =
N_Others_Choice;
end Is_Others_Aggregate;
----------------------------
-- Is_Top_Level_Aggregate --
----------------------------
function Is_Top_Level_Aggregate (Expr : Node_Id) return Boolean is
begin
return Nkind (Parent (Expr)) /= N_Aggregate
and then (Nkind (Parent (Expr)) /= N_Component_Association
or else Nkind (Parent (Parent (Expr))) /= N_Aggregate);
end Is_Top_Level_Aggregate;
--------------------------------
-- Make_String_Into_Aggregate --
--------------------------------
procedure Make_String_Into_Aggregate (N : Node_Id) is
Exprs : constant List_Id := New_List;
Loc : constant Source_Ptr := Sloc (N);
Str : constant String_Id := Strval (N);
Strlen : constant Nat := String_Length (Str);
C : Char_Code;
C_Node : Node_Id;
New_N : Node_Id;
P : Source_Ptr;
begin
P := Loc + 1;
for J in 1 .. Strlen loop
C := Get_String_Char (Str, J);
Set_Character_Literal_Name (C);
C_Node :=
Make_Character_Literal (P,
Chars => Name_Find,
Char_Literal_Value => UI_From_CC (C));
Set_Etype (C_Node, Any_Character);
Append_To (Exprs, C_Node);
P := P + 1;
-- Something special for wide strings???
end loop;
New_N := Make_Aggregate (Loc, Expressions => Exprs);
Set_Analyzed (New_N);
Set_Etype (New_N, Any_Composite);
Rewrite (N, New_N);
end Make_String_Into_Aggregate;
-----------------------
-- Resolve_Aggregate --
-----------------------
procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is
Loc : constant Source_Ptr := Sloc (N);
Pkind : constant Node_Kind := Nkind (Parent (N));
Aggr_Subtyp : Entity_Id;
-- The actual aggregate subtype. This is not necessarily the same as Typ
-- which is the subtype of the context in which the aggregate was found.
begin
-- Ignore junk empty aggregate resulting from parser error
if No (Expressions (N))
and then No (Component_Associations (N))
and then not Null_Record_Present (N)
then
return;
end if;
-- If the aggregate has box-initialized components, its type must be
-- frozen so that initialization procedures can properly be called
-- in the resolution that follows. The replacement of boxes with
-- initialization calls is properly an expansion activity but it must
-- be done during resolution.
if Expander_Active
and then Present (Component_Associations (N))
then
declare
Comp : Node_Id;
begin
Comp := First (Component_Associations (N));
while Present (Comp) loop
if Box_Present (Comp) then
Insert_Actions (N, Freeze_Entity (Typ, N));
exit;
end if;
Next (Comp);
end loop;
end;
end if;
-- An unqualified aggregate is restricted in SPARK to:
-- An aggregate item inside an aggregate for a multi-dimensional array
-- An expression being assigned to an unconstrained array, but only if
-- the aggregate specifies a value for OTHERS only.
if Nkind (Parent (N)) = N_Qualified_Expression then
if Is_Array_Type (Typ) then
Check_Qualified_Aggregate (Number_Dimensions (Typ), N);
else
Check_Qualified_Aggregate (1, N);
end if;
else
if Is_Array_Type (Typ)
and then Nkind (Parent (N)) = N_Assignment_Statement
and then not Is_Constrained (Etype (Name (Parent (N))))
then
if not Is_Others_Aggregate (N) then
Check_SPARK_05_Restriction
("array aggregate should have only OTHERS", N);
end if;
elsif Is_Top_Level_Aggregate (N) then
Check_SPARK_05_Restriction ("aggregate should be qualified", N);
-- The legality of this unqualified aggregate is checked by calling
-- Check_Qualified_Aggregate from one of its enclosing aggregate,
-- unless one of these already causes an error to be issued.
else
null;
end if;
end if;
-- Check for aggregates not allowed in configurable run-time mode.
-- We allow all cases of aggregates that do not come from source, since
-- these are all assumed to be small (e.g. bounds of a string literal).
-- We also allow aggregates of types we know to be small.
if not Support_Aggregates_On_Target
and then Comes_From_Source (N)
and then (not Known_Static_Esize (Typ) or else Esize (Typ) > 64)
then
Error_Msg_CRT ("aggregate", N);
end if;
-- Ada 2005 (AI-287): Limited aggregates allowed
-- In an instance, ignore aggregate subcomponents tnat may be limited,
-- because they originate in view conflicts. If the original aggregate
-- is legal and the actuals are legal, the aggregate itself is legal.
if Is_Limited_Type (Typ)
and then Ada_Version < Ada_2005
and then not In_Instance
then
Error_Msg_N ("aggregate type cannot be limited", N);
Explain_Limited_Type (Typ, N);
elsif Is_Class_Wide_Type (Typ) then
Error_Msg_N ("type of aggregate cannot be class-wide", N);
elsif Typ = Any_String
or else Typ = Any_Composite
then
Error_Msg_N ("no unique type for aggregate", N);
Set_Etype (N, Any_Composite);
elsif Is_Array_Type (Typ) and then Null_Record_Present (N) then
Error_Msg_N ("null record forbidden in array aggregate", N);
elsif Is_Record_Type (Typ) then
Resolve_Record_Aggregate (N, Typ);
elsif Is_Array_Type (Typ) then
-- First a special test, for the case of a positional aggregate
-- of characters which can be replaced by a string literal.
-- Do not perform this transformation if this was a string literal to
-- start with, whose components needed constraint checks, or if the
-- component type is non-static, because it will require those checks
-- and be transformed back into an aggregate.
if Number_Dimensions (Typ) = 1
and then Is_Standard_Character_Type (Component_Type (Typ))
and then No (Component_Associations (N))
and then not Is_Limited_Composite (Typ)
and then not Is_Private_Composite (Typ)
and then not Is_Bit_Packed_Array (Typ)
and then Nkind (Original_Node (Parent (N))) /= N_String_Literal
and then Is_OK_Static_Subtype (Component_Type (Typ))
then
declare
Expr : Node_Id;
begin
Expr := First (Expressions (N));
while Present (Expr) loop
exit when Nkind (Expr) /= N_Character_Literal;
Next (Expr);
end loop;
if No (Expr) then
Start_String;
Expr := First (Expressions (N));
while Present (Expr) loop
Store_String_Char (UI_To_CC (Char_Literal_Value (Expr)));
Next (Expr);
end loop;
Rewrite (N, Make_String_Literal (Loc, End_String));
Analyze_And_Resolve (N, Typ);
return;
end if;
end;
end if;
-- Here if we have a real aggregate to deal with
Array_Aggregate : declare
Aggr_Resolved : Boolean;
Aggr_Typ : constant Entity_Id := Etype (Typ);
-- This is the unconstrained array type, which is the type against
-- which the aggregate is to be resolved. Typ itself is the array
-- type of the context which may not be the same subtype as the
-- subtype for the final aggregate.
begin
-- In the following we determine whether an OTHERS choice is
-- allowed inside the array aggregate. The test checks the context
-- in which the array aggregate occurs. If the context does not
-- permit it, or the aggregate type is unconstrained, an OTHERS
-- choice is not allowed (except that it is always allowed on the
-- right-hand side of an assignment statement; in this case the
-- constrainedness of the type doesn't matter).
-- If expansion is disabled (generic context, or semantics-only
-- mode) actual subtypes cannot be constructed, and the type of an
-- object may be its unconstrained nominal type. However, if the
-- context is an assignment, we assume that OTHERS is allowed,
-- because the target of the assignment will have a constrained
-- subtype when fully compiled.
-- Note that there is no node for Explicit_Actual_Parameter.
-- To test for this context we therefore have to test for node
-- N_Parameter_Association which itself appears only if there is a
-- formal parameter. Consequently we also need to test for
-- N_Procedure_Call_Statement or N_Function_Call.
-- The context may be an N_Reference node, created by expansion.
-- Legality of the others clause was established in the source,
-- so the context is legal.
Set_Etype (N, Aggr_Typ); -- May be overridden later on
if Pkind = N_Assignment_Statement
or else (Is_Constrained (Typ)
and then
(Pkind = N_Parameter_Association or else
Pkind = N_Function_Call or else
Pkind = N_Procedure_Call_Statement or else
Pkind = N_Generic_Association or else
Pkind = N_Formal_Object_Declaration or else
Pkind = N_Simple_Return_Statement or else
Pkind = N_Object_Declaration or else
Pkind = N_Component_Declaration or else
Pkind = N_Parameter_Specification or else
Pkind = N_Qualified_Expression or else
Pkind = N_Reference or else
Pkind = N_Aggregate or else
Pkind = N_Extension_Aggregate or else
Pkind = N_Component_Association))
then
Aggr_Resolved :=
Resolve_Array_Aggregate
(N,
Index => First_Index (Aggr_Typ),
Index_Constr => First_Index (Typ),
Component_Typ => Component_Type (Typ),
Others_Allowed => True);
elsif not Expander_Active
and then Pkind = N_Assignment_Statement
then
Aggr_Resolved :=
Resolve_Array_Aggregate
(N,
Index => First_Index (Aggr_Typ),
Index_Constr => First_Index (Typ),
Component_Typ => Component_Type (Typ),
Others_Allowed => True);
else
Aggr_Resolved :=
Resolve_Array_Aggregate
(N,
Index => First_Index (Aggr_Typ),
Index_Constr => First_Index (Aggr_Typ),
Component_Typ => Component_Type (Typ),
Others_Allowed => False);
end if;
if not Aggr_Resolved then
-- A parenthesized expression may have been intended as an
-- aggregate, leading to a type error when analyzing the
-- component. This can also happen for a nested component
-- (see Analyze_Aggr_Expr).
if Paren_Count (N) > 0 then
Error_Msg_N
("positional aggregate cannot have one component", N);
end if;
Aggr_Subtyp := Any_Composite;
else
Aggr_Subtyp := Array_Aggr_Subtype (N, Typ);
end if;
Set_Etype (N, Aggr_Subtyp);
end Array_Aggregate;
elsif Is_Private_Type (Typ)
and then Present (Full_View (Typ))
and then (In_Inlined_Body or In_Instance_Body)
and then Is_Composite_Type (Full_View (Typ))
then
Resolve (N, Full_View (Typ));
else
Error_Msg_N ("illegal context for aggregate", N);
end if;
-- If we can determine statically that the evaluation of the aggregate
-- raises Constraint_Error, then replace the aggregate with an
-- N_Raise_Constraint_Error node, but set the Etype to the right
-- aggregate subtype. Gigi needs this.
if Raises_Constraint_Error (N) then
Aggr_Subtyp := Etype (N);
Rewrite (N,
Make_Raise_Constraint_Error (Loc, Reason => CE_Range_Check_Failed));
Set_Raises_Constraint_Error (N);
Set_Etype (N, Aggr_Subtyp);
Set_Analyzed (N);
end if;
Check_Function_Writable_Actuals (N);
end Resolve_Aggregate;
-----------------------------
-- Resolve_Array_Aggregate --
-----------------------------
function Resolve_Array_Aggregate
(N : Node_Id;
Index : Node_Id;
Index_Constr : Node_Id;
Component_Typ : Entity_Id;
Others_Allowed : Boolean) return Boolean
is
Loc : constant Source_Ptr := Sloc (N);
Failure : constant Boolean := False;
Success : constant Boolean := True;
Index_Typ : constant Entity_Id := Etype (Index);
Index_Typ_Low : constant Node_Id := Type_Low_Bound (Index_Typ);
Index_Typ_High : constant Node_Id := Type_High_Bound (Index_Typ);
-- The type of the index corresponding to the array sub-aggregate along
-- with its low and upper bounds.
Index_Base : constant Entity_Id := Base_Type (Index_Typ);
Index_Base_Low : constant Node_Id := Type_Low_Bound (Index_Base);
Index_Base_High : constant Node_Id := Type_High_Bound (Index_Base);
-- Ditto for the base type
function Add (Val : Uint; To : Node_Id) return Node_Id;
-- Creates a new expression node where Val is added to expression To.
-- Tries to constant fold whenever possible. To must be an already
-- analyzed expression.
procedure Check_Bound (BH : Node_Id; AH : in out Node_Id);
-- Checks that AH (the upper bound of an array aggregate) is less than
-- or equal to BH (the upper bound of the index base type). If the check
-- fails, a warning is emitted, the Raises_Constraint_Error flag of N is
-- set, and AH is replaced with a duplicate of BH.
procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id);
-- Checks that range AL .. AH is compatible with range L .. H. Emits a
-- warning if not and sets the Raises_Constraint_Error flag in N.
procedure Check_Length (L, H : Node_Id; Len : Uint);
-- Checks that range L .. H contains at least Len elements. Emits a
-- warning if not and sets the Raises_Constraint_Error flag in N.
function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean;
-- Returns True if range L .. H is dynamic or null
procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean);
-- Given expression node From, this routine sets OK to False if it
-- cannot statically evaluate From. Otherwise it stores this static
-- value into Value.
function Resolve_Aggr_Expr
(Expr : Node_Id;
Single_Elmt : Boolean) return Boolean;
-- Resolves aggregate expression Expr. Returns False if resolution
-- fails. If Single_Elmt is set to False, the expression Expr may be
-- used to initialize several array aggregate elements (this can happen
-- for discrete choices such as "L .. H => Expr" or the OTHERS choice).
-- In this event we do not resolve Expr unless expansion is disabled.
-- To know why, see the DELAYED COMPONENT RESOLUTION note above.
--
-- NOTE: In the case of "... => <>", we pass the in the
-- N_Component_Association node as Expr, since there is no Expression in
-- that case, and we need a Sloc for the error message.
---------
-- Add --
---------
function Add (Val : Uint; To : Node_Id) return Node_Id is
Expr_Pos : Node_Id;
Expr : Node_Id;
To_Pos : Node_Id;
begin
if Raises_Constraint_Error (To) then
return To;
end if;
-- First test if we can do constant folding
if Compile_Time_Known_Value (To)
or else Nkind (To) = N_Integer_Literal
then
Expr_Pos := Make_Integer_Literal (Loc, Expr_Value (To) + Val);
Set_Is_Static_Expression (Expr_Pos);
Set_Etype (Expr_Pos, Etype (To));
Set_Analyzed (Expr_Pos, Analyzed (To));
if not Is_Enumeration_Type (Index_Typ) then
Expr := Expr_Pos;
-- If we are dealing with enumeration return
-- Index_Typ'Val (Expr_Pos)
else
Expr :=
Make_Attribute_Reference
(Loc,
Prefix => New_Occurrence_Of (Index_Typ, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (Expr_Pos));
end if;
return Expr;
end if;
-- If we are here no constant folding possible
if not Is_Enumeration_Type (Index_Base) then
Expr :=
Make_Op_Add (Loc,
Left_Opnd => Duplicate_Subexpr (To),
Right_Opnd => Make_Integer_Literal (Loc, Val));
-- If we are dealing with enumeration return
-- Index_Typ'Val (Index_Typ'Pos (To) + Val)
else
To_Pos :=
Make_Attribute_Reference
(Loc,
Prefix => New_Occurrence_Of (Index_Typ, Loc),
Attribute_Name => Name_Pos,
Expressions => New_List (Duplicate_Subexpr (To)));
Expr_Pos :=
Make_Op_Add (Loc,
Left_Opnd => To_Pos,
Right_Opnd => Make_Integer_Literal (Loc, Val));
Expr :=
Make_Attribute_Reference
(Loc,
Prefix => New_Occurrence_Of (Index_Typ, Loc),
Attribute_Name => Name_Val,
Expressions => New_List (Expr_Pos));
-- If the index type has a non standard representation, the
-- attributes 'Val and 'Pos expand into function calls and the
-- resulting expression is considered non-safe for reevaluation
-- by the backend. Relocate it into a constant temporary in order
-- to make it safe for reevaluation.
if Has_Non_Standard_Rep (Etype (N)) then
declare
Def_Id : Entity_Id;
begin
Def_Id := Make_Temporary (Loc, 'R', Expr);
Set_Etype (Def_Id, Index_Typ);
Insert_Action (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Def_Id,
Object_Definition =>
New_Occurrence_Of (Index_Typ, Loc),
Constant_Present => True,
Expression => Relocate_Node (Expr)));
Expr := New_Occurrence_Of (Def_Id, Loc);
end;
end if;
end if;
return Expr;
end Add;
-----------------
-- Check_Bound --
-----------------
procedure Check_Bound (BH : Node_Id; AH : in out Node_Id) is
Val_BH : Uint;
Val_AH : Uint;
OK_BH : Boolean;
OK_AH : Boolean;
begin
Get (Value => Val_BH, From => BH, OK => OK_BH);
Get (Value => Val_AH, From => AH, OK => OK_AH);
if OK_BH and then OK_AH and then Val_BH < Val_AH then
Set_Raises_Constraint_Error (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("upper bound out of range<<", AH);
Error_Msg_N ("\Constraint_Error [<<", AH);
-- You need to set AH to BH or else in the case of enumerations
-- indexes we will not be able to resolve the aggregate bounds.
AH := Duplicate_Subexpr (BH);
end if;
end Check_Bound;
------------------
-- Check_Bounds --
------------------
procedure Check_Bounds (L, H : Node_Id; AL, AH : Node_Id) is
Val_L : Uint;
Val_H : Uint;
Val_AL : Uint;
Val_AH : Uint;
OK_L : Boolean;
OK_H : Boolean;
OK_AL : Boolean;
OK_AH : Boolean;
pragma Warnings (Off, OK_AL);
pragma Warnings (Off, OK_AH);
begin
if Raises_Constraint_Error (N)
or else Dynamic_Or_Null_Range (AL, AH)
then
return;
end if;
Get (Value => Val_L, From => L, OK => OK_L);
Get (Value => Val_H, From => H, OK => OK_H);
Get (Value => Val_AL, From => AL, OK => OK_AL);
Get (Value => Val_AH, From => AH, OK => OK_AH);
if OK_L and then Val_L > Val_AL then
Set_Raises_Constraint_Error (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("lower bound of aggregate out of range<<", N);
Error_Msg_N ("\Constraint_Error [<<", N);
end if;
if OK_H and then Val_H < Val_AH then
Set_Raises_Constraint_Error (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("upper bound of aggregate out of range<<", N);
Error_Msg_N ("\Constraint_Error [<<", N);
end if;
end Check_Bounds;
------------------
-- Check_Length --
------------------
procedure Check_Length (L, H : Node_Id; Len : Uint) is
Val_L : Uint;
Val_H : Uint;
OK_L : Boolean;
OK_H : Boolean;
Range_Len : Uint;
begin
if Raises_Constraint_Error (N) then
return;
end if;
Get (Value => Val_L, From => L, OK => OK_L);
Get (Value => Val_H, From => H, OK => OK_H);
if not OK_L or else not OK_H then
return;
end if;
-- If null range length is zero
if Val_L > Val_H then
Range_Len := Uint_0;
else
Range_Len := Val_H - Val_L + 1;
end if;
if Range_Len < Len then
Set_Raises_Constraint_Error (N);
Error_Msg_Warn := SPARK_Mode /= On;
Error_Msg_N ("too many elements<<", N);
Error_Msg_N ("\Constraint_Error [<<", N);
end if;
end Check_Length;
---------------------------
-- Dynamic_Or_Null_Range --
---------------------------
function Dynamic_Or_Null_Range (L, H : Node_Id) return Boolean is
Val_L : Uint;
Val_H : Uint;
OK_L : Boolean;
OK_H : Boolean;
begin
Get (Value => Val_L, From => L, OK => OK_L);
Get (Value => Val_H, From => H, OK => OK_H);
return not OK_L or else not OK_H
or else not Is_OK_Static_Expression (L)
or else not Is_OK_Static_Expression (H)
or else Val_L > Val_H;
end Dynamic_Or_Null_Range;
---------
-- Get --
---------
procedure Get (Value : out Uint; From : Node_Id; OK : out Boolean) is
begin
OK := True;
if Compile_Time_Known_Value (From) then
Value := Expr_Value (From);
-- If expression From is something like Some_Type'Val (10) then
-- Value = 10.
elsif Nkind (From) = N_Attribute_Reference
and then Attribute_Name (From) = Name_Val
and then Compile_Time_Known_Value (First (Expressions (From)))
then
Value := Expr_Value (First (Expressions (From)));
else
Value := Uint_0;
OK := False;
end if;
end Get;
-----------------------
-- Resolve_Aggr_Expr --
-----------------------
function Resolve_Aggr_Expr
(Expr : Node_Id;
Single_Elmt : Boolean) return Boolean
is
Nxt_Ind : constant Node_Id := Next_Index (Index);
Nxt_Ind_Constr : constant Node_Id := Next_Index (Index_Constr);
-- Index is the current index corresponding to the expression
Resolution_OK : Boolean := True;
-- Set to False if resolution of the expression failed
begin
-- Defend against previous errors
if Nkind (Expr) = N_Error
or else Error_Posted (Expr)
then
return True;
end if;
-- If the array type against which we are resolving the aggregate
-- has several dimensions, the expressions nested inside the
-- aggregate must be further aggregates (or strings).
if Present (Nxt_Ind) then
if Nkind (Expr) /= N_Aggregate then
-- A string literal can appear where a one-dimensional array
-- of characters is expected. If the literal looks like an
-- operator, it is still an operator symbol, which will be
-- transformed into a string when analyzed.
if Is_Character_Type (Component_Typ)
and then No (Next_Index (Nxt_Ind))
and then Nkind_In (Expr, N_String_Literal, N_Operator_Symbol)
then
-- A string literal used in a multidimensional array
-- aggregate in place of the final one-dimensional
-- aggregate must not be enclosed in parentheses.
if Paren_Count (Expr) /= 0 then
Error_Msg_N ("no parenthesis allowed here", Expr);
end if;
Make_String_Into_Aggregate (Expr);
else
Error_Msg_N ("nested array aggregate expected", Expr);
-- If the expression is parenthesized, this may be
-- a missing component association for a 1-aggregate.
if Paren_Count (Expr) > 0 then
Error_Msg_N
("\if single-component aggregate is intended, "
& "write e.g. (1 ='> ...)", Expr);
end if;
return Failure;
end if;
end if;
-- If it's "... => <>", nothing to resolve
if Nkind (Expr) = N_Component_Association then
pragma Assert (Box_Present (Expr));
return Success;
end if;
-- Ada 2005 (AI-231): Propagate the type to the nested aggregate.
-- Required to check the null-exclusion attribute (if present).
-- This value may be overridden later on.
Set_Etype (Expr, Etype (N));
Resolution_OK := Resolve_Array_Aggregate
(Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed);
else
-- If it's "... => <>", nothing to resolve
if Nkind (Expr) = N_Component_Association then
pragma Assert (Box_Present (Expr));
return Success;
end if;
-- Do not resolve the expressions of discrete or others choices
-- unless the expression covers a single component, or the
-- expander is inactive.
-- In SPARK mode, expressions that can perform side-effects will
-- be recognized by the gnat2why back-end, and the whole
-- subprogram will be ignored. So semantic analysis can be
-- performed safely.
if Single_Elmt
or else not Expander_Active
or else In_Spec_Expression
then
Analyze_And_Resolve (Expr, Component_Typ);
Check_Expr_OK_In_Limited_Aggregate (Expr);
Check_Non_Static_Context (Expr);
Aggregate_Constraint_Checks (Expr, Component_Typ);
Check_Unset_Reference (Expr);
end if;
end if;
-- If an aggregate component has a type with predicates, an explicit
-- predicate check must be applied, as for an assignment statement,
-- because the aggegate might not be expanded into individual
-- component assignments.
if Present (Predicate_Function (Component_Typ)) then
Apply_Predicate_Check (Expr, Component_Typ);
end if;
if Raises_Constraint_Error (Expr)
and then Nkind (Parent (Expr)) /= N_Component_Association
then
Set_Raises_Constraint_Error (N);
end if;
-- If the expression has been marked as requiring a range check,
-- then generate it here. It's a bit odd to be generating such
-- checks in the analyzer, but harmless since Generate_Range_Check
-- does nothing (other than making sure Do_Range_Check is set) if
-- the expander is not active.
if Do_Range_Check (Expr) then
Generate_Range_Check (Expr, Component_Typ, CE_Range_Check_Failed);
end if;
return Resolution_OK;
end Resolve_Aggr_Expr;
-- Variables local to Resolve_Array_Aggregate
Assoc : Node_Id;
Choice : Node_Id;
Expr : Node_Id;
Discard : Node_Id;
Delete_Choice : Boolean;
-- Used when replacing a subtype choice with predicate by a list
Aggr_Low : Node_Id := Empty;
Aggr_High : Node_Id := Empty;
-- The actual low and high bounds of this sub-aggregate
Choices_Low : Node_Id := Empty;
Choices_High : Node_Id := Empty;
-- The lowest and highest discrete choices values for a named aggregate
Nb_Elements : Uint := Uint_0;
-- The number of elements in a positional aggregate
Others_Present : Boolean := False;
Nb_Choices : Nat := 0;
-- Contains the overall number of named choices in this sub-aggregate
Nb_Discrete_Choices : Nat := 0;
-- The overall number of discrete choices (not counting others choice)
Case_Table_Size : Nat;
-- Contains the size of the case table needed to sort aggregate choices
-- Start of processing for Resolve_Array_Aggregate
begin
-- Ignore junk empty aggregate resulting from parser error
if No (Expressions (N))
and then No (Component_Associations (N))
and then not Null_Record_Present (N)
then
return False;
end if;
-- STEP 1: make sure the aggregate is correctly formatted
if Present (Component_Associations (N)) then
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Choice := First (Choices (Assoc));
Delete_Choice := False;
while Present (Choice) loop
if Nkind (Choice) = N_Others_Choice then
Others_Present := True;
if Choice /= First (Choices (Assoc))
or else Present (Next (Choice))
then
Error_Msg_N
("OTHERS must appear alone in a choice list", Choice);
return Failure;
end if;
if Present (Next (Assoc)) then
Error_Msg_N
("OTHERS must appear last in an aggregate", Choice);
return Failure;
end if;
if Ada_Version = Ada_83
and then Assoc /= First (Component_Associations (N))
and then Nkind_In (Parent (N), N_Assignment_Statement,
N_Object_Declaration)
then
Error_Msg_N
("(Ada 83) illegal context for OTHERS choice", N);
end if;
elsif Is_Entity_Name (Choice) then
Analyze (Choice);
declare
E : constant Entity_Id := Entity (Choice);
New_Cs : List_Id;
P : Node_Id;
C : Node_Id;
begin
if Is_Type (E) and then Has_Predicates (E) then
Freeze_Before (N, E);
if Has_Dynamic_Predicate_Aspect (E) then
Error_Msg_NE
("subtype& has dynamic predicate, not allowed "
& "in aggregate choice", Choice, E);
elsif not Is_OK_Static_Subtype (E) then
Error_Msg_NE
("non-static subtype& has predicate, not allowed "
& "in aggregate choice", Choice, E);
end if;
-- If the subtype has a static predicate, replace the
-- original choice with the list of individual values
-- covered by the predicate.
if Present (Static_Discrete_Predicate (E)) then
Delete_Choice := True;
New_Cs := New_List;
P := First (Static_Discrete_Predicate (E));
while Present (P) loop
C := New_Copy (P);
Set_Sloc (C, Sloc (Choice));
Append_To (New_Cs, C);
Next (P);
end loop;
Insert_List_After (Choice, New_Cs);
end if;
end if;
end;
end if;
Nb_Choices := Nb_Choices + 1;
declare
C : constant Node_Id := Choice;
begin
Next (Choice);
if Delete_Choice then
Remove (C);
Nb_Choices := Nb_Choices - 1;
Delete_Choice := False;
end if;
end;
end loop;
Next (Assoc);
end loop;
end if;
-- At this point we know that the others choice, if present, is by
-- itself and appears last in the aggregate. Check if we have mixed
-- positional and discrete associations (other than the others choice).
if Present (Expressions (N))
and then (Nb_Choices > 1
or else (Nb_Choices = 1 and then not Others_Present))
then
Error_Msg_N
("named association cannot follow positional association",
First (Choices (First (Component_Associations (N)))));
return Failure;
end if;
-- Test for the validity of an others choice if present
if Others_Present and then not Others_Allowed then
Error_Msg_N
("OTHERS choice not allowed here",
First (Choices (First (Component_Associations (N)))));
return Failure;
end if;
-- Protect against cascaded errors
if Etype (Index_Typ) = Any_Type then
return Failure;
end if;
-- STEP 2: Process named components
if No (Expressions (N)) then
if Others_Present then
Case_Table_Size := Nb_Choices - 1;
else
Case_Table_Size := Nb_Choices;
end if;
Step_2 : declare
Low : Node_Id;
High : Node_Id;
-- Denote the lowest and highest values in an aggregate choice
S_Low : Node_Id := Empty;
S_High : Node_Id := Empty;
-- if a choice in an aggregate is a subtype indication these
-- denote the lowest and highest values of the subtype
Table : Case_Table_Type (0 .. Case_Table_Size);
-- Used to sort all the different choice values. Entry zero is
-- reserved for sorting purposes.
Single_Choice : Boolean;
-- Set to true every time there is a single discrete choice in a
-- discrete association
Prev_Nb_Discrete_Choices : Nat;
-- Used to keep track of the number of discrete choices in the
-- current association.
Errors_Posted_On_Choices : Boolean := False;
-- Keeps track of whether any choices have semantic errors
function Empty_Range (A : Node_Id) return Boolean;
-- If an association covers an empty range, some warnings on the
-- expression of the association can be disabled.
-----------------
-- Empty_Range --
-----------------
function Empty_Range (A : Node_Id) return Boolean is
R : constant Node_Id := First (Choices (A));
begin
return No (Next (R))
and then Nkind (R) = N_Range
and then Compile_Time_Compare
(Low_Bound (R), High_Bound (R), False) = GT;
end Empty_Range;
-- Start of processing for Step_2
begin
-- STEP 2 (A): Check discrete choices validity
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
Prev_Nb_Discrete_Choices := Nb_Discrete_Choices;
Choice := First (Choices (Assoc));
loop
Analyze (Choice);
if Nkind (Choice) = N_Others_Choice then
Single_Choice := False;
exit;
-- Test for subtype mark without constraint
elsif Is_Entity_Name (Choice) and then
Is_Type (Entity (Choice))
then
if Base_Type (Entity (Choice)) /= Index_Base then
Error_Msg_N
("invalid subtype mark in aggregate choice",
Choice);
return Failure;
end if;
-- Case of subtype indication
elsif Nkind (Choice) = N_Subtype_Indication then
Resolve_Discrete_Subtype_Indication (Choice, Index_Base);
if Has_Dynamic_Predicate_Aspect
(Entity (Subtype_Mark (Choice)))
then
Error_Msg_NE
("subtype& has dynamic predicate, "
& "not allowed in aggregate choice",
Choice, Entity (Subtype_Mark (Choice)));
end if;
-- Does the subtype indication evaluation raise CE?
Get_Index_Bounds (Subtype_Mark (Choice), S_Low, S_High);
Get_Index_Bounds (Choice, Low, High);
Check_Bounds (S_Low, S_High, Low, High);
-- Case of range or expression
else
Resolve (Choice, Index_Base);
Check_Unset_Reference (Choice);
Check_Non_Static_Context (Choice);
-- If semantic errors were posted on the choice, then
-- record that for possible early return from later
-- processing (see handling of enumeration choices).
if Error_Posted (Choice) then
Errors_Posted_On_Choices := True;
end if;
-- Do not range check a choice. This check is redundant
-- since this test is already done when we check that the
-- bounds of the array aggregate are within range.
Set_Do_Range_Check (Choice, False);
-- In SPARK, the choice must be static
if not (Is_OK_Static_Expression (Choice)
or else (Nkind (Choice) = N_Range
and then Is_OK_Static_Range (Choice)))
then
Check_SPARK_05_Restriction
("choice should be static", Choice);
end if;
end if;
-- If we could not resolve the discrete choice stop here
if Etype (Choice) = Any_Type then
return Failure;
-- If the discrete choice raises CE get its original bounds
elsif Nkind (Choice) = N_Raise_Constraint_Error then
Set_Raises_Constraint_Error (N);
Get_Index_Bounds (Original_Node (Choice), Low, High);
-- Otherwise get its bounds as usual
else
Get_Index_Bounds (Choice, Low, High);
end if;
if (Dynamic_Or_Null_Range (Low, High)
or else (Nkind (Choice) = N_Subtype_Indication
and then
Dynamic_Or_Null_Range (S_Low, S_High)))
and then Nb_Choices /= 1
then
Error_Msg_N
("dynamic or empty choice in aggregate "
& "must be the only choice", Choice);
return Failure;
end if;
Nb_Discrete_Choices := Nb_Discrete_Choices + 1;
Table (Nb_Discrete_Choices).Lo := Low;
Table (Nb_Discrete_Choices).Hi := High;
Table (Nb_Discrete_Choices).Choice := Choice;
Next (Choice);
if No (Choice) then
-- Check if we have a single discrete choice and whether
-- this discrete choice specifies a single value.
Single_Choice :=
(Nb_Discrete_Choices = Prev_Nb_Discrete_Choices + 1)
and then (Low = High);
exit;
end if;
end loop;
-- Ada 2005 (AI-231)
if Ada_Version >= Ada_2005
and then Known_Null (Expression (Assoc))
and then not Empty_Range (Assoc)
then
Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
end if;
-- Ada 2005 (AI-287): In case of default initialized component
-- we delay the resolution to the expansion phase.
if Box_Present (Assoc) then
-- Ada 2005 (AI-287): In case of default initialization of a
-- component the expander will generate calls to the
-- corresponding initialization subprogram. We need to call
-- Resolve_Aggr_Expr to check the rules about
-- dimensionality.
if not Resolve_Aggr_Expr
(Assoc, Single_Elmt => Single_Choice)
then
return Failure;
end if;
elsif not Resolve_Aggr_Expr
(Expression (Assoc), Single_Elmt => Single_Choice)
then
return Failure;
-- Check incorrect use of dynamically tagged expression
-- We differentiate here two cases because the expression may
-- not be decorated. For example, the analysis and resolution
-- of the expression associated with the others choice will be
-- done later with the full aggregate. In such case we
-- duplicate the expression tree to analyze the copy and
-- perform the required check.
elsif not Present (Etype (Expression (Assoc))) then
declare
Save_Analysis : constant Boolean := Full_Analysis;
Expr : constant Node_Id :=
New_Copy_Tree (Expression (Assoc));
begin
Expander_Mode_Save_And_Set (False);
Full_Analysis := False;
-- Analyze the expression, making sure it is properly
-- attached to the tree before we do the analysis.
Set_Parent (Expr, Parent (Expression (Assoc)));
Analyze (Expr);
-- If the expression is a literal, propagate this info
-- to the expression in the association, to enable some
-- optimizations downstream.
if Is_Entity_Name (Expr)
and then Present (Entity (Expr))
and then Ekind (Entity (Expr)) = E_Enumeration_Literal
then
Analyze_And_Resolve
(Expression (Assoc), Component_Typ);
end if;
Full_Analysis := Save_Analysis;
Expander_Mode_Restore;
if Is_Tagged_Type (Etype (Expr)) then
Check_Dynamically_Tagged_Expression
(Expr => Expr,
Typ => Component_Type (Etype (N)),
Related_Nod => N);
end if;
end;
elsif Is_Tagged_Type (Etype (Expression (Assoc))) then
Check_Dynamically_Tagged_Expression
(Expr => Expression (Assoc),
Typ => Component_Type (Etype (N)),
Related_Nod => N);
end if;
Next (Assoc);
end loop;
-- If aggregate contains more than one choice then these must be
-- static. Check for duplicate and missing values.
-- Note: there is duplicated code here wrt Check_Choice_Set in
-- the body of Sem_Case, and it is possible we could just reuse
-- that procedure. To be checked ???
if Nb_Discrete_Choices > 1 then
Check_Choices : declare
Choice : Node_Id;
-- Location of choice for messages
Hi_Val : Uint;
Lo_Val : Uint;
-- High end of one range and Low end of the next. Should be
-- contiguous if there is no hole in the list of values.
Lo_Dup : Uint;
Hi_Dup : Uint;
-- End points of duplicated range
Missing_Or_Duplicates : Boolean := False;
-- Set True if missing or duplicate choices found
procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id);
-- Output continuation message with a representation of the
-- bounds (just Lo if Lo = Hi, else Lo .. Hi). C is the
-- choice node where the message is to be posted.
------------------------
-- Output_Bad_Choices --
------------------------
procedure Output_Bad_Choices (Lo, Hi : Uint; C : Node_Id) is
begin
-- Enumeration type case
if Is_Enumeration_Type (Index_Typ) then
Error_Msg_Name_1 :=
Chars (Get_Enum_Lit_From_Pos (Index_Typ, Lo, Loc));
Error_Msg_Name_2 :=
Chars (Get_Enum_Lit_From_Pos (Index_Typ, Hi, Loc));
if Lo = Hi then
Error_Msg_N ("\\ %!", C);
else
Error_Msg_N ("\\ % .. %!", C);
end if;
-- Integer types case
else
Error_Msg_Uint_1 := Lo;
Error_Msg_Uint_2 := Hi;
if Lo = Hi then
Error_Msg_N ("\\ ^!", C);
else
Error_Msg_N ("\\ ^ .. ^!", C);
end if;
end if;
end Output_Bad_Choices;
-- Start of processing for Check_Choices
begin
Sort_Case_Table (Table);
-- First we do a quick linear loop to find out if we have
-- any duplicates or missing entries (usually we have a
-- legal aggregate, so this will get us out quickly).
for J in 1 .. Nb_Discrete_Choices - 1 loop
Hi_Val := Expr_Value (Table (J).Hi);
Lo_Val := Expr_Value (Table (J + 1).Lo);
if Lo_Val <= Hi_Val
or else (Lo_Val > Hi_Val + 1
and then not Others_Present)
then
Missing_Or_Duplicates := True;
exit;
end if;
end loop;
-- If we have missing or duplicate entries, first fill in
-- the Highest entries to make life easier in the following
-- loops to detect bad entries.
if Missing_Or_Duplicates then
Table (1).Highest := Expr_Value (Table (1).Hi);
for J in 2 .. Nb_Discrete_Choices loop
Table (J).Highest :=
UI_Max
(Table (J - 1).Highest, Expr_Value (Table (J).Hi));
end loop;
-- Loop through table entries to find duplicate indexes
for J in 2 .. Nb_Discrete_Choices loop
Lo_Val := Expr_Value (Table (J).Lo);
Hi_Val := Expr_Value (Table (J).Hi);
-- Case where we have duplicates (the lower bound of
-- this choice is less than or equal to the highest
-- high bound found so far).
if Lo_Val <= Table (J - 1).Highest then
-- We move backwards looking for duplicates. We can
-- abandon this loop as soon as we reach a choice
-- highest value that is less than Lo_Val.
for K in reverse 1 .. J - 1 loop
exit when Table (K).Highest < Lo_Val;
-- Here we may have duplicates between entries
-- for K and J. Get range of duplicates.
Lo_Dup :=
UI_Max (Lo_Val, Expr_Value (Table (K).Lo));
Hi_Dup :=
UI_Min (Hi_Val, Expr_Value (Table (K).Hi));
-- Nothing to do if duplicate range is null
if Lo_Dup > Hi_Dup then
null;
-- Otherwise place proper message
else
-- We place message on later choice, with a
-- line reference to the earlier choice.
if Sloc (Table (J).Choice) <
Sloc (Table (K).Choice)
then
Choice := Table (K).Choice;
Error_Msg_Sloc := Sloc (Table (J).Choice);
else
Choice := Table (J).Choice;
Error_Msg_Sloc := Sloc (Table (K).Choice);
end if;
if Lo_Dup = Hi_Dup then
Error_Msg_N
("index value in array aggregate "
& "duplicates the one given#!", Choice);
else
Error_Msg_N
("index values in array aggregate "
& "duplicate those given#!", Choice);
end if;
Output_Bad_Choices (Lo_Dup, Hi_Dup, Choice);
end if;
end loop;
end if;
end loop;
-- Loop through entries in table to find missing indexes.
-- Not needed if others, since missing impossible.
if not Others_Present then
for J in 2 .. Nb_Discrete_Choices loop
Lo_Val := Expr_Value (Table (J).Lo);
Hi_Val := Table (J - 1).Highest;
if Lo_Val > Hi_Val + 1 then
declare
Error_Node : Node_Id;
begin
-- If the choice is the bound of a range in
-- a subtype indication, it is not in the
-- source lists for the aggregate itself, so
-- post the error on the aggregate. Otherwise
-- post it on choice itself.
Choice := Table (J).Choice;
if Is_List_Member (Choice) then
Error_Node := Choice;
else
Error_Node := N;
end if;
if Hi_Val + 1 = Lo_Val - 1 then
Error_Msg_N
("missing index value "
& "in array aggregate!", Error_Node);
else
Error_Msg_N
("missing index values "
& "in array aggregate!", Error_Node);
end if;
Output_Bad_Choices
(Hi_Val + 1, Lo_Val - 1, Error_Node);
end;
end if;
end loop;
end if;
-- If either missing or duplicate values, return failure
Set_Etype (N, Any_Composite);
return Failure;
end if;
end Check_Choices;
end if;
-- STEP 2 (B): Compute aggregate bounds and min/max choices values
if Nb_Discrete_Choices > 0 then
Choices_Low := Table (1).Lo;
Choices_High := Table (Nb_Discrete_Choices).Hi;
end if;
-- If Others is present, then bounds of aggregate come from the
-- index constraint (not the choices in the aggregate itself).
if Others_Present then
Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
-- No others clause present
else
-- Special processing if others allowed and not present. This
-- means that the bounds of the aggregate come from the index
-- constraint (and the length must match).
if Others_Allowed then
Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
-- If others allowed, and no others present, then the array
-- should cover all index values. If it does not, we will
-- get a length check warning, but there is two cases where
-- an additional warning is useful:
-- If we have no positional components, and the length is
-- wrong (which we can tell by others being allowed with
-- missing components), and the index type is an enumeration
-- type, then issue appropriate warnings about these missing
-- components. They are only warnings, since the aggregate
-- is fine, it's just the wrong length. We skip this check
-- for standard character types (since there are no literals
-- and it is too much trouble to concoct them), and also if
-- any of the bounds have values that are not known at
-- compile time.
-- Another case warranting a warning is when the length
-- is right, but as above we have an index type that is
-- an enumeration, and the bounds do not match. This is a
-- case where dubious sliding is allowed and we generate a
-- warning that the bounds do not match.
if No (Expressions (N))
and then Nkind (Index) = N_Range
and then Is_Enumeration_Type (Etype (Index))
and then not Is_Standard_Character_Type (Etype (Index))
and then Compile_Time_Known_Value (Aggr_Low)
and then Compile_Time_Known_Value (Aggr_High)
and then Compile_Time_Known_Value (Choices_Low)
and then Compile_Time_Known_Value (Choices_High)
then
-- If any of the expressions or range bounds in choices
-- have semantic errors, then do not attempt further
-- resolution, to prevent cascaded errors.
if Errors_Posted_On_Choices then
return Failure;
end if;
declare
ALo : constant Node_Id := Expr_Value_E (Aggr_Low);
AHi : constant Node_Id := Expr_Value_E (Aggr_High);
CLo : constant Node_Id := Expr_Value_E (Choices_Low);
CHi : constant Node_Id := Expr_Value_E (Choices_High);
Ent : Entity_Id;
begin
-- Warning case 1, missing values at start/end. Only
-- do the check if the number of entries is too small.
if (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
<
(Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
then
Error_Msg_N
("missing index value(s) in array aggregate??",
N);
-- Output missing value(s) at start
if Chars (ALo) /= Chars (CLo) then
Ent := Prev (CLo);
if Chars (ALo) = Chars (Ent) then
Error_Msg_Name_1 := Chars (ALo);
Error_Msg_N ("\ %??", N);
else
Error_Msg_Name_1 := Chars (ALo);
Error_Msg_Name_2 := Chars (Ent);
Error_Msg_N ("\ % .. %??", N);
end if;
end if;
-- Output missing value(s) at end
if Chars (AHi) /= Chars (CHi) then
Ent := Next (CHi);
if Chars (AHi) = Chars (Ent) then
Error_Msg_Name_1 := Chars (Ent);
Error_Msg_N ("\ %??", N);
else
Error_Msg_Name_1 := Chars (Ent);
Error_Msg_Name_2 := Chars (AHi);
Error_Msg_N ("\ % .. %??", N);
end if;
end if;
-- Warning case 2, dubious sliding. The First_Subtype
-- test distinguishes between a constrained type where
-- sliding is not allowed (so we will get a warning
-- later that Constraint_Error will be raised), and
-- the unconstrained case where sliding is permitted.
elsif (Enumeration_Pos (CHi) - Enumeration_Pos (CLo))
=
(Enumeration_Pos (AHi) - Enumeration_Pos (ALo))
and then Chars (ALo) /= Chars (CLo)
and then
not Is_Constrained (First_Subtype (Etype (N)))
then
Error_Msg_N
("bounds of aggregate do not match target??", N);
end if;
end;
end if;
end if;
-- If no others, aggregate bounds come from aggregate
Aggr_Low := Choices_Low;
Aggr_High := Choices_High;
end if;
end Step_2;
-- STEP 3: Process positional components
else
-- STEP 3 (A): Process positional elements
Expr := First (Expressions (N));
Nb_Elements := Uint_0;
while Present (Expr) loop
Nb_Elements := Nb_Elements + 1;
-- Ada 2005 (AI-231)
if Ada_Version >= Ada_2005 and then Known_Null (Expr) then
Check_Can_Never_Be_Null (Etype (N), Expr);
end if;
if not Resolve_Aggr_Expr (Expr, Single_Elmt => True) then
return Failure;
end if;
-- Check incorrect use of dynamically tagged expression
if Is_Tagged_Type (Etype (Expr)) then
Check_Dynamically_Tagged_Expression
(Expr => Expr,
Typ => Component_Type (Etype (N)),
Related_Nod => N);
end if;
Next (Expr);
end loop;
if Others_Present then
Assoc := Last (Component_Associations (N));
-- Ada 2005 (AI-231)
if Ada_Version >= Ada_2005 and then Known_Null (Assoc) then
Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
end if;
-- Ada 2005 (AI-287): In case of default initialized component,
-- we delay the resolution to the expansion phase.
if Box_Present (Assoc) then
-- Ada 2005 (AI-287): In case of default initialization of a
-- component the expander will generate calls to the
-- corresponding initialization subprogram. We need to call
-- Resolve_Aggr_Expr to check the rules about
-- dimensionality.
if not Resolve_Aggr_Expr (Assoc, Single_Elmt => False) then
return Failure;
end if;
elsif not Resolve_Aggr_Expr (Expression (Assoc),
Single_Elmt => False)
then
return Failure;
-- Check incorrect use of dynamically tagged expression. The
-- expression of the others choice has not been resolved yet.
-- In order to diagnose the semantic error we create a duplicate
-- tree to analyze it and perform the check.
else
declare
Save_Analysis : constant Boolean := Full_Analysis;
Expr : constant Node_Id :=
New_Copy_Tree (Expression (Assoc));
begin
Expander_Mode_Save_And_Set (False);
Full_Analysis := False;
Analyze (Expr);
Full_Analysis := Save_Analysis;
Expander_Mode_Restore;
if Is_Tagged_Type (Etype (Expr)) then
Check_Dynamically_Tagged_Expression
(Expr => Expr,
Typ => Component_Type (Etype (N)),
Related_Nod => N);
end if;
end;
end if;
end if;
-- STEP 3 (B): Compute the aggregate bounds
if Others_Present then
Get_Index_Bounds (Index_Constr, Aggr_Low, Aggr_High);
else
if Others_Allowed then
Get_Index_Bounds (Index_Constr, Aggr_Low, Discard);
else
Aggr_Low := Index_Typ_Low;
end if;
Aggr_High := Add (Nb_Elements - 1, To => Aggr_Low);
Check_Bound (Index_Base_High, Aggr_High);
end if;
end if;
-- STEP 4: Perform static aggregate checks and save the bounds
-- Check (A)
Check_Bounds (Index_Typ_Low, Index_Typ_High, Aggr_Low, Aggr_High);
Check_Bounds (Index_Base_Low, Index_Base_High, Aggr_Low, Aggr_High);
-- Check (B)
if Others_Present and then Nb_Discrete_Choices > 0 then
Check_Bounds (Aggr_Low, Aggr_High, Choices_Low, Choices_High);
Check_Bounds (Index_Typ_Low, Index_Typ_High,
Choices_Low, Choices_High);
Check_Bounds (Index_Base_Low, Index_Base_High,
Choices_Low, Choices_High);
-- Check (C)
elsif Others_Present and then Nb_Elements > 0 then
Check_Length (Aggr_Low, Aggr_High, Nb_Elements);
Check_Length (Index_Typ_Low, Index_Typ_High, Nb_Elements);
Check_Length (Index_Base_Low, Index_Base_High, Nb_Elements);
end if;
if Raises_Constraint_Error (Aggr_Low)
or else Raises_Constraint_Error (Aggr_High)
then
Set_Raises_Constraint_Error (N);
end if;
Aggr_Low := Duplicate_Subexpr (Aggr_Low);
-- Do not duplicate Aggr_High if Aggr_High = Aggr_Low + Nb_Elements
-- since the addition node returned by Add is not yet analyzed. Attach
-- to tree and analyze first. Reset analyzed flag to ensure it will get
-- analyzed when it is a literal bound whose type must be properly set.
if Others_Present or else Nb_Discrete_Choices > 0 then
Aggr_High := Duplicate_Subexpr (Aggr_High);
if Etype (Aggr_High) = Universal_Integer then
Set_Analyzed (Aggr_High, False);
end if;
end if;
-- If the aggregate already has bounds attached to it, it means this is
-- a positional aggregate created as an optimization by
-- Exp_Aggr.Convert_To_Positional, so we don't want to change those
-- bounds.
if Present (Aggregate_Bounds (N)) and then not Others_Allowed then
Aggr_Low := Low_Bound (Aggregate_Bounds (N));
Aggr_High := High_Bound (Aggregate_Bounds (N));
end if;
Set_Aggregate_Bounds
(N, Make_Range (Loc, Low_Bound => Aggr_Low, High_Bound => Aggr_High));
-- The bounds may contain expressions that must be inserted upwards.
-- Attach them fully to the tree. After analysis, remove side effects
-- from upper bound, if still needed.
Set_Parent (Aggregate_Bounds (N), N);
Analyze_And_Resolve (Aggregate_Bounds (N), Index_Typ);
Check_Unset_Reference (Aggregate_Bounds (N));
if not Others_Present and then Nb_Discrete_Choices = 0 then
Set_High_Bound
(Aggregate_Bounds (N),
Duplicate_Subexpr (High_Bound (Aggregate_Bounds (N))));
end if;
-- Check the dimensions of each component in the array aggregate
Analyze_Dimension_Array_Aggregate (N, Component_Typ);
return Success;
end Resolve_Array_Aggregate;
---------------------------------
-- Resolve_Extension_Aggregate --
---------------------------------
-- There are two cases to consider:
-- a) If the ancestor part is a type mark, the components needed are the
-- difference between the components of the expected type and the
-- components of the given type mark.
-- b) If the ancestor part is an expression, it must be unambiguous, and
-- once we have its type we can also compute the needed components as in
-- the previous case. In both cases, if the ancestor type is not the
-- immediate ancestor, we have to build this ancestor recursively.
-- In both cases, discriminants of the ancestor type do not play a role in
-- the resolution of the needed components, because inherited discriminants
-- cannot be used in a type extension. As a result we can compute
-- independently the list of components of the ancestor type and of the
-- expected type.
procedure Resolve_Extension_Aggregate (N : Node_Id; Typ : Entity_Id) is
A : constant Node_Id := Ancestor_Part (N);
A_Type : Entity_Id;
I : Interp_Index;
It : Interp;
function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean;
-- If the type is limited, verify that the ancestor part is a legal
-- expression (aggregate or function call, including 'Input)) that does
-- not require a copy, as specified in 7.5(2).
function Valid_Ancestor_Type return Boolean;
-- Verify that the type of the ancestor part is a non-private ancestor
-- of the expected type, which must be a type extension.
----------------------------
-- Valid_Limited_Ancestor --
----------------------------
function Valid_Limited_Ancestor (Anc : Node_Id) return Boolean is
begin
if Is_Entity_Name (Anc) and then Is_Type (Entity (Anc)) then
return True;
-- The ancestor must be a call or an aggregate, but a call may
-- have been expanded into a temporary, so check original node.
elsif Nkind_In (Anc, N_Aggregate,
N_Extension_Aggregate,
N_Function_Call)
then
return True;
elsif Nkind (Original_Node (Anc)) = N_Function_Call then
return True;
elsif Nkind (Anc) = N_Attribute_Reference
and then Attribute_Name (Anc) = Name_Input
then
return True;
elsif Nkind (Anc) = N_Qualified_Expression then
return Valid_Limited_Ancestor (Expression (Anc));
else
return False;
end if;
end Valid_Limited_Ancestor;
-------------------------
-- Valid_Ancestor_Type --
-------------------------
function Valid_Ancestor_Type return Boolean is
Imm_Type : Entity_Id;
begin
Imm_Type := Base_Type (Typ);
while Is_Derived_Type (Imm_Type) loop
if Etype (Imm_Type) = Base_Type (A_Type) then
return True;
-- The base type of the parent type may appear as a private
-- extension if it is declared as such in a parent unit of the
-- current one. For consistency of the subsequent analysis use
-- the partial view for the ancestor part.
elsif Is_Private_Type (Etype (Imm_Type))
and then Present (Full_View (Etype (Imm_Type)))
and then Base_Type (A_Type) = Full_View (Etype (Imm_Type))
then
A_Type := Etype (Imm_Type);
return True;
-- The parent type may be a private extension. The aggregate is
-- legal if the type of the aggregate is an extension of it that
-- is not a private extension.
elsif Is_Private_Type (A_Type)
and then not Is_Private_Type (Imm_Type)
and then Present (Full_View (A_Type))
and then Base_Type (Full_View (A_Type)) = Etype (Imm_Type)
then
return True;
else
Imm_Type := Etype (Base_Type (Imm_Type));
end if;
end loop;
-- If previous loop did not find a proper ancestor, report error
Error_Msg_NE ("expect ancestor type of &", A, Typ);
return False;
end Valid_Ancestor_Type;
-- Start of processing for Resolve_Extension_Aggregate
begin
-- Analyze the ancestor part and account for the case where it is a
-- parameterless function call.
Analyze (A);
Check_Parameterless_Call (A);
-- In SPARK, the ancestor part cannot be a type mark
if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
Check_SPARK_05_Restriction ("ancestor part cannot be a type mark", A);
-- AI05-0115: if the ancestor part is a subtype mark, the ancestor
-- must not have unknown discriminants.
if Has_Unknown_Discriminants (Root_Type (Typ)) then
Error_Msg_NE
("aggregate not available for type& whose ancestor "
& "has unknown discriminants", N, Typ);
end if;
end if;
if not Is_Tagged_Type (Typ) then
Error_Msg_N ("type of extension aggregate must be tagged", N);
return;
elsif Is_Limited_Type (Typ) then
-- Ada 2005 (AI-287): Limited aggregates are allowed
if Ada_Version < Ada_2005 then
Error_Msg_N ("aggregate type cannot be limited", N);
Explain_Limited_Type (Typ, N);
return;
elsif Valid_Limited_Ancestor (A) then
null;
else
Error_Msg_N
("limited ancestor part must be aggregate or function call", A);
end if;
elsif Is_Class_Wide_Type (Typ) then
Error_Msg_N ("aggregate cannot be of a class-wide type", N);
return;
end if;
if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
A_Type := Get_Full_View (Entity (A));
if Valid_Ancestor_Type then
Set_Entity (A, A_Type);
Set_Etype (A, A_Type);
Validate_Ancestor_Part (N);
Resolve_Record_Aggregate (N, Typ);
end if;
elsif Nkind (A) /= N_Aggregate then
if Is_Overloaded (A) then
A_Type := Any_Type;
Get_First_Interp (A, I, It);
while Present (It.Typ) loop
-- Only consider limited interpretations in the Ada 2005 case
if Is_Tagged_Type (It.Typ)
and then (Ada_Version >= Ada_2005
or else not Is_Limited_Type (It.Typ))
then
if A_Type /= Any_Type then
Error_Msg_N ("cannot resolve expression", A);
return;
else
A_Type := It.Typ;
end if;
end if;
Get_Next_Interp (I, It);
end loop;
if A_Type = Any_Type then
if Ada_Version >= Ada_2005 then
Error_Msg_N
("ancestor part must be of a tagged type", A);
else
Error_Msg_N
("ancestor part must be of a nonlimited tagged type", A);
end if;
return;
end if;
else
A_Type := Etype (A);
end if;
if Valid_Ancestor_Type then
Resolve (A, A_Type);
Check_Unset_Reference (A);
Check_Non_Static_Context (A);
-- The aggregate is illegal if the ancestor expression is a call
-- to a function with a limited unconstrained result, unless the
-- type of the aggregate is a null extension. This restriction
-- was added in AI05-67 to simplify implementation.
if Nkind (A) = N_Function_Call
and then Is_Limited_Type (A_Type)
and then not Is_Null_Extension (Typ)
and then not Is_Constrained (A_Type)
then
Error_Msg_N
("type of limited ancestor part must be constrained", A);
-- Reject the use of CPP constructors that leave objects partially
-- initialized. For example:
-- type CPP_Root is tagged limited record ...
-- pragma Import (CPP, CPP_Root);
-- type CPP_DT is new CPP_Root and Iface ...
-- pragma Import (CPP, CPP_DT);
-- type Ada_DT is new CPP_DT with ...
-- Obj : Ada_DT := Ada_DT'(New_CPP_Root with others => <>);
-- Using the constructor of CPP_Root the slots of the dispatch
-- table of CPP_DT cannot be set, and the secondary tag of
-- CPP_DT is unknown.
elsif Nkind (A) = N_Function_Call
and then Is_CPP_Constructor_Call (A)
and then Enclosing_CPP_Parent (Typ) /= A_Type
then
Error_Msg_NE
("??must use 'C'P'P constructor for type &", A,
Enclosing_CPP_Parent (Typ));
-- The following call is not needed if the previous warning
-- is promoted to an error.
Resolve_Record_Aggregate (N, Typ);
elsif Is_Class_Wide_Type (Etype (A))
and then Nkind (Original_Node (A)) = N_Function_Call
then
-- If the ancestor part is a dispatching call, it appears
-- statically to be a legal ancestor, but it yields any member
-- of the class, and it is not possible to determine whether
-- it is an ancestor of the extension aggregate (much less
-- which ancestor). It is not possible to determine the
-- components of the extension part.
-- This check implements AI-306, which in fact was motivated by
-- an AdaCore query to the ARG after this test was added.
Error_Msg_N ("ancestor part must be statically tagged", A);
else
Resolve_Record_Aggregate (N, Typ);
end if;
end if;
else
Error_Msg_N ("no unique type for this aggregate", A);
end if;
Check_Function_Writable_Actuals (N);
end Resolve_Extension_Aggregate;
------------------------------
-- Resolve_Record_Aggregate --
------------------------------
procedure Resolve_Record_Aggregate (N : Node_Id; Typ : Entity_Id) is
Assoc : Node_Id;
-- N_Component_Association node belonging to the input aggregate N
Expr : Node_Id;
Positional_Expr : Node_Id;
Component : Entity_Id;
Component_Elmt : Elmt_Id;
Components : constant Elist_Id := New_Elmt_List;
-- Components is the list of the record components whose value must be
-- provided in the aggregate. This list does include discriminants.
New_Assoc_List : constant List_Id := New_List;
New_Assoc : Node_Id;
-- New_Assoc_List is the newly built list of N_Component_Association
-- nodes. New_Assoc is one such N_Component_Association node in it.
-- Note that while Assoc and New_Assoc contain the same kind of nodes,
-- they are used to iterate over two different N_Component_Association
-- lists.
Others_Etype : Entity_Id := Empty;
-- This variable is used to save the Etype of the last record component
-- that takes its value from the others choice. Its purpose is:
--
-- (a) make sure the others choice is useful
--
-- (b) make sure the type of all the components whose value is
-- subsumed by the others choice are the same.
--
-- This variable is updated as a side effect of function Get_Value.
Is_Box_Present : Boolean := False;
Others_Box : Boolean := False;
-- Ada 2005 (AI-287): Variables used in case of default initialization
-- to provide a functionality similar to Others_Etype. Box_Present
-- indicates that the component takes its default initialization;
-- Others_Box indicates that at least one component takes its default
-- initialization. Similar to Others_Etype, they are also updated as a
-- side effect of function Get_Value.
procedure Add_Association
(Component : Entity_Id;
Expr : Node_Id;
Assoc_List : List_Id;
Is_Box_Present : Boolean := False);
-- Builds a new N_Component_Association node which associates Component
-- to expression Expr and adds it to the association list being built,
-- either New_Assoc_List, or the association being built for an inner
-- aggregate.
function Discr_Present (Discr : Entity_Id) return Boolean;
-- If aggregate N is a regular aggregate this routine will return True.
-- Otherwise, if N is an extension aggregate, Discr is a discriminant
-- whose value may already have been specified by N's ancestor part.
-- This routine checks whether this is indeed the case and if so returns
-- False, signaling that no value for Discr should appear in N's
-- aggregate part. Also, in this case, the routine appends to
-- New_Assoc_List the discriminant value specified in the ancestor part.
--
-- If the aggregate is in a context with expansion delayed, it will be
-- reanalyzed. The inherited discriminant values must not be reinserted
-- in the component list to prevent spurious errors, but they must be
-- present on first analysis to build the proper subtype indications.
-- The flag Inherited_Discriminant is used to prevent the re-insertion.
function Get_Value
(Compon : Node_Id;
From : List_Id;
Consider_Others_Choice : Boolean := False)
return Node_Id;
-- Given a record component stored in parameter Compon, this function
-- returns its value as it appears in the list From, which is a list
-- of N_Component_Association nodes.
--
-- If no component association has a choice for the searched component,
-- the value provided by the others choice is returned, if there is one,
-- and Consider_Others_Choice is set to true. Otherwise Empty is
-- returned. If there is more than one component association giving a
-- value for the searched record component, an error message is emitted
-- and the first found value is returned.
--
-- If Consider_Others_Choice is set and the returned expression comes
-- from the others choice, then Others_Etype is set as a side effect.
-- An error message is emitted if the components taking their value from
-- the others choice do not have same type.
function New_Copy_Tree_And_Copy_Dimensions
(Source : Node_Id;
Map : Elist_Id := No_Elist;
New_Sloc : Source_Ptr := No_Location;
New_Scope : Entity_Id := Empty) return Node_Id;
-- Same as New_Copy_Tree (defined in Sem_Util), except that this routine
-- also copies the dimensions of Source to the returned node.
procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id);
-- Analyzes and resolves expression Expr against the Etype of the
-- Component. This routine also applies all appropriate checks to Expr.
-- It finally saves a Expr in the newly created association list that
-- will be attached to the final record aggregate. Note that if the
-- Parent pointer of Expr is not set then Expr was produced with a
-- New_Copy_Tree or some such.
---------------------
-- Add_Association --
---------------------
procedure Add_Association
(Component : Entity_Id;
Expr : Node_Id;
Assoc_List : List_Id;
Is_Box_Present : Boolean := False)
is
Loc : Source_Ptr;
Choice_List : constant List_Id := New_List;
New_Assoc : Node_Id;
begin
-- If this is a box association the expression is missing, so
-- use the Sloc of the aggregate itself for the new association.
if Present (Expr) then
Loc := Sloc (Expr);
else
Loc := Sloc (N);
end if;
Append (New_Occurrence_Of (Component, Loc), Choice_List);
New_Assoc :=
Make_Component_Association (Loc,
Choices => Choice_List,
Expression => Expr,
Box_Present => Is_Box_Present);
Append (New_Assoc, Assoc_List);
end Add_Association;
-------------------
-- Discr_Present --
-------------------
function Discr_Present (Discr : Entity_Id) return Boolean is
Regular_Aggr : constant Boolean := Nkind (N) /= N_Extension_Aggregate;
Loc : Source_Ptr;
Ancestor : Node_Id;
Comp_Assoc : Node_Id;
Discr_Expr : Node_Id;
Ancestor_Typ : Entity_Id;
Orig_Discr : Entity_Id;
D : Entity_Id;
D_Val : Elmt_Id := No_Elmt; -- stop junk warning
Ancestor_Is_Subtyp : Boolean;
begin
if Regular_Aggr then
return True;
end if;
-- Check whether inherited discriminant values have already been
-- inserted in the aggregate. This will be the case if we are
-- re-analyzing an aggregate whose expansion was delayed.
if Present (Component_Associations (N)) then
Comp_Assoc := First (Component_Associations (N));
while Present (Comp_Assoc) loop
if Inherited_Discriminant (Comp_Assoc) then
return True;
end if;
Next (Comp_Assoc);
end loop;
end if;
Ancestor := Ancestor_Part (N);
Ancestor_Typ := Etype (Ancestor);
Loc := Sloc (Ancestor);
-- For a private type with unknown discriminants, use the underlying
-- record view if it is available.
if Has_Unknown_Discriminants (Ancestor_Typ)
and then Present (Full_View (Ancestor_Typ))
and then Present (Underlying_Record_View (Full_View (Ancestor_Typ)))
then
Ancestor_Typ := Underlying_Record_View (Full_View (Ancestor_Typ));
end if;
Ancestor_Is_Subtyp :=
Is_Entity_Name (Ancestor) and then Is_Type (Entity (Ancestor));
-- If the ancestor part has no discriminants clearly N's aggregate
-- part must provide a value for Discr.
if not Has_Discriminants (Ancestor_Typ) then
return True;
-- If the ancestor part is an unconstrained subtype mark then the
-- Discr must be present in N's aggregate part.
elsif Ancestor_Is_Subtyp
and then not Is_Constrained (Entity (Ancestor))
then
return True;
end if;
-- Now look to see if Discr was specified in the ancestor part
if Ancestor_Is_Subtyp then
D_Val := First_Elmt (Discriminant_Constraint (Entity (Ancestor)));
end if;
Orig_Discr := Original_Record_Component (Discr);
D := First_Discriminant (Ancestor_Typ);
while Present (D) loop
-- If Ancestor has already specified Disc value then insert its
-- value in the final aggregate.
if Original_Record_Component (D) = Orig_Discr then
if Ancestor_Is_Subtyp then
Discr_Expr := New_Copy_Tree (Node (D_Val));
else
Discr_Expr :=
Make_Selected_Component (Loc,
Prefix => Duplicate_Subexpr (Ancestor),
Selector_Name => New_Occurrence_Of (Discr, Loc));
end if;
Resolve_Aggr_Expr (Discr_Expr, Discr);
Set_Inherited_Discriminant (Last (New_Assoc_List));
return False;
end if;
Next_Discriminant (D);
if Ancestor_Is_Subtyp then
Next_Elmt (D_Val);
end if;
end loop;
return True;
end Discr_Present;
---------------
-- Get_Value --
---------------
function Get_Value
(Compon : Node_Id;
From : List_Id;
Consider_Others_Choice : Boolean := False)
return Node_Id
is
Typ : constant Entity_Id := Etype (Compon);
Assoc : Node_Id;
Expr : Node_Id := Empty;
Selector_Name : Node_Id;
begin
Is_Box_Present := False;
if No (From) then
return Empty;
end if;
Assoc := First (From);
while Present (Assoc) loop
Selector_Name := First (Choices (Assoc));
while Present (Selector_Name) loop
if Nkind (Selector_Name) = N_Others_Choice then
if Consider_Others_Choice and then No (Expr) then
-- We need to duplicate the expression for each
-- successive component covered by the others choice.
-- This is redundant if the others_choice covers only
-- one component (small optimization possible???), but
-- indispensable otherwise, because each one must be
-- expanded individually to preserve side-effects.
-- Ada 2005 (AI-287): In case of default initialization
-- of components, we duplicate the corresponding default
-- expression (from the record type declaration). The
-- copy must carry the sloc of the association (not the
-- original expression) to prevent spurious elaboration
-- checks when the default includes function calls.
if Box_Present (Assoc) then
Others_Box := True;
Is_Box_Present := True;
if Expander_Active then
return
New_Copy_Tree_And_Copy_Dimensions
(Expression (Parent (Compon)),
New_Sloc => Sloc (Assoc));
else
return Expression (Parent (Compon));
end if;
else
if Present (Others_Etype)
and then Base_Type (Others_Etype) /= Base_Type (Typ)
then
-- If the components are of an anonymous access
-- type they are distinct, but this is legal in
-- Ada 2012 as long as designated types match.
if (Ekind (Typ) = E_Anonymous_Access_Type
or else Ekind (Typ) =
E_Anonymous_Access_Subprogram_Type)
and then Designated_Type (Typ) =
Designated_Type (Others_Etype)
then
null;
else
Error_Msg_N
("components in OTHERS choice must "
& "have same type", Selector_Name);
end if;
end if;
Others_Etype := Typ;
-- Copy expression so that it is resolved
-- independently for each component, This is needed
-- for accessibility checks on compoents of anonymous
-- access types, even in compile_only mode.
if not Inside_A_Generic then
-- In ASIS mode, preanalyze the expression in an
-- others association before making copies for
-- separate resolution and accessibility checks.
-- This ensures that the type of the expression is
-- available to ASIS in all cases, in particular if
-- the expression is itself an aggregate.
if ASIS_Mode then
Preanalyze_And_Resolve (Expression (Assoc), Typ);
end if;
return
New_Copy_Tree_And_Copy_Dimensions
(Expression (Assoc));
else
return Expression (Assoc);
end if;
end if;
end if;
elsif Chars (Compon) = Chars (Selector_Name) then
if No (Expr) then
-- Ada 2005 (AI-231)
if Ada_Version >= Ada_2005
and then Known_Null (Expression (Assoc))
then
Check_Can_Never_Be_Null (Compon, Expression (Assoc));
end if;
-- We need to duplicate the expression when several
-- components are grouped together with a "|" choice.
-- For instance "filed1 | filed2 => Expr"
-- Ada 2005 (AI-287)
if Box_Present (Assoc) then
Is_Box_Present := True;
-- Duplicate the default expression of the component
-- from the record type declaration, so a new copy
-- can be attached to the association.
-- Note that we always copy the default expression,
-- even when the association has a single choice, in
-- order to create a proper association for the
-- expanded aggregate.
-- Component may have no default, in which case the
-- expression is empty and the component is default-
-- initialized, but an association for the component
-- exists, and it is not covered by an others clause.
-- Scalar and private types have no initialization
-- procedure, so they remain uninitialized. If the
-- target of the aggregate is a constant this
-- deserves a warning.
if No (Expression (Parent (Compon)))
and then not Has_Non_Null_Base_Init_Proc (Typ)
and then not Has_Aspect (Typ, Aspect_Default_Value)
and then not Is_Concurrent_Type (Typ)
and then Nkind (Parent (N)) = N_Object_Declaration
and then Constant_Present (Parent (N))
then
Error_Msg_Node_2 := Typ;
Error_Msg_NE
("component&? of type& is uninitialized",
Assoc, Selector_Name);
-- An additional reminder if the component type
-- is a generic formal.
if Is_Generic_Type (Base_Type (Typ)) then
Error_Msg_NE
("\instance should provide actual type with "
& "initialization for&", Assoc, Typ);
end if;
end if;
return
New_Copy_Tree_And_Copy_Dimensions
(Expression (Parent (Compon)));
else
if Present (Next (Selector_Name)) then
Expr := New_Copy_Tree_And_Copy_Dimensions
(Expression (Assoc));
else
Expr := Expression (Assoc);
end if;
end if;
Generate_Reference (Compon, Selector_Name, 'm');
else
Error_Msg_NE
("more than one value supplied for &",
Selector_Name, Compon);
end if;
end if;
Next (Selector_Name);
end loop;
Next (Assoc);
end loop;
return Expr;
end Get_Value;
---------------------------------------
-- New_Copy_Tree_And_Copy_Dimensions --
---------------------------------------
function New_Copy_Tree_And_Copy_Dimensions
(Source : Node_Id;
Map : Elist_Id := No_Elist;
New_Sloc : Source_Ptr := No_Location;
New_Scope : Entity_Id := Empty) return Node_Id
is
New_Copy : constant Node_Id :=
New_Copy_Tree (Source, Map, New_Sloc, New_Scope);
begin
-- Move the dimensions of Source to New_Copy
Copy_Dimensions (Source, New_Copy);
return New_Copy;
end New_Copy_Tree_And_Copy_Dimensions;
-----------------------
-- Resolve_Aggr_Expr --
-----------------------
procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id) is
Expr_Type : Entity_Id := Empty;
New_C : Entity_Id := Component;
New_Expr : Node_Id;
function Has_Expansion_Delayed (Expr : Node_Id) return Boolean;
-- If the expression is an aggregate (possibly qualified) then its
-- expansion is delayed until the enclosing aggregate is expanded
-- into assignments. In that case, do not generate checks on the
-- expression, because they will be generated later, and will other-
-- wise force a copy (to remove side-effects) that would leave a
-- dynamic-sized aggregate in the code, something that gigi cannot
-- handle.
Relocate : Boolean;
-- Set to True if the resolved Expr node needs to be relocated when
-- attached to the newly created association list. This node need not
-- be relocated if its parent pointer is not set. In fact in this
-- case Expr is the output of a New_Copy_Tree call. If Relocate is
-- True then we have analyzed the expression node in the original
-- aggregate and hence it needs to be relocated when moved over to
-- the new association list.
---------------------------
-- Has_Expansion_Delayed --
---------------------------
function Has_Expansion_Delayed (Expr : Node_Id) return Boolean is
Kind : constant Node_Kind := Nkind (Expr);
begin
return (Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate)
and then Present (Etype (Expr))
and then Is_Record_Type (Etype (Expr))
and then Expansion_Delayed (Expr))
or else (Kind = N_Qualified_Expression
and then Has_Expansion_Delayed (Expression (Expr)));
end Has_Expansion_Delayed;
-- Start of processing for Resolve_Aggr_Expr
begin
-- If the type of the component is elementary or the type of the
-- aggregate does not contain discriminants, use the type of the
-- component to resolve Expr.
if Is_Elementary_Type (Etype (Component))
or else not Has_Discriminants (Etype (N))
then
Expr_Type := Etype (Component);
-- Otherwise we have to pick up the new type of the component from
-- the new constrained subtype of the aggregate. In fact components
-- which are of a composite type might be constrained by a
-- discriminant, and we want to resolve Expr against the subtype were
-- all discriminant occurrences are replaced with their actual value.
else
New_C := First_Component (Etype (N));
while Present (New_C) loop
if Chars (New_C) = Chars (Component) then
Expr_Type := Etype (New_C);
exit;
end if;
Next_Component (New_C);
end loop;
pragma Assert (Present (Expr_Type));
-- For each range in an array type where a discriminant has been
-- replaced with the constraint, check that this range is within
-- the range of the base type. This checks is done in the init
-- proc for regular objects, but has to be done here for
-- aggregates since no init proc is called for them.
if Is_Array_Type (Expr_Type) then
declare
Index : Node_Id;
-- Range of the current constrained index in the array
Orig_Index : Node_Id := First_Index (Etype (Component));
-- Range corresponding to the range Index above in the
-- original unconstrained record type. The bounds of this
-- range may be governed by discriminants.
Unconstr_Index : Node_Id := First_Index (Etype (Expr_Type));
-- Range corresponding to the range Index above for the
-- unconstrained array type. This range is needed to apply
-- range checks.
begin
Index := First_Index (Expr_Type);
while Present (Index) loop
if Depends_On_Discriminant (Orig_Index) then
Apply_Range_Check (Index, Etype (Unconstr_Index));
end if;
Next_Index (Index);
Next_Index (Orig_Index);
Next_Index (Unconstr_Index);
end loop;
end;
end if;
end if;
-- If the Parent pointer of Expr is not set, Expr is an expression
-- duplicated by New_Tree_Copy (this happens for record aggregates
-- that look like (Field1 | Filed2 => Expr) or (others => Expr)).
-- Such a duplicated expression must be attached to the tree
-- before analysis and resolution to enforce the rule that a tree
-- fragment should never be analyzed or resolved unless it is
-- attached to the current compilation unit.
if No (Parent (Expr)) then
Set_Parent (Expr, N);
Relocate := False;
else
Relocate := True;
end if;
Analyze_And_Resolve (Expr, Expr_Type);
Check_Expr_OK_In_Limited_Aggregate (Expr);
Check_Non_Static_Context (Expr);
Check_Unset_Reference (Expr);
-- Check wrong use of class-wide types
if Is_Class_Wide_Type (Etype (Expr)) then
Error_Msg_N ("dynamically tagged expression not allowed", Expr);
end if;
if not Has_Expansion_Delayed (Expr) then
Aggregate_Constraint_Checks (Expr, Expr_Type);
end if;
-- If an aggregate component has a type with predicates, an explicit
-- predicate check must be applied, as for an assignment statement,
-- because the aggegate might not be expanded into individual
-- component assignments.
if Present (Predicate_Function (Expr_Type)) then
Apply_Predicate_Check (Expr, Expr_Type);
end if;
if Raises_Constraint_Error (Expr) then
Set_Raises_Constraint_Error (N);
end if;
-- If the expression has been marked as requiring a range check, then
-- generate it here. It's a bit odd to be generating such checks in
-- the analyzer, but harmless since Generate_Range_Check does nothing
-- (other than making sure Do_Range_Check is set) if the expander is
-- not active.
if Do_Range_Check (Expr) then
Generate_Range_Check (Expr, Expr_Type, CE_Range_Check_Failed);
end if;
if Relocate then
New_Expr := Relocate_Node (Expr);
-- Since New_Expr is not gonna be analyzed later on, we need to
-- propagate here the dimensions form Expr to New_Expr.
Copy_Dimensions (Expr, New_Expr);
else
New_Expr := Expr;
end if;
Add_Association (New_C, New_Expr, New_Assoc_List);
end Resolve_Aggr_Expr;
-- Start of processing for Resolve_Record_Aggregate
begin
-- A record aggregate is restricted in SPARK:
-- Each named association can have only a single choice.
-- OTHERS cannot be used.
-- Positional and named associations cannot be mixed.
if Present (Component_Associations (N))
and then Present (First (Component_Associations (N)))
then
if Present (Expressions (N)) then
Check_SPARK_05_Restriction
("named association cannot follow positional one",
First (Choices (First (Component_Associations (N)))));
end if;
declare
Assoc : Node_Id;
begin
Assoc := First (Component_Associations (N));
while Present (Assoc) loop
if List_Length (Choices (Assoc)) > 1 then
Check_SPARK_05_Restriction
("component association in record aggregate must "
& "contain a single choice", Assoc);
end if;
if Nkind (First (Choices (Assoc))) = N_Others_Choice then
Check_SPARK_05_Restriction
("record aggregate cannot contain OTHERS", Assoc);
end if;
Assoc := Next (Assoc);
end loop;
end;
end if;
-- We may end up calling Duplicate_Subexpr on expressions that are
-- attached to New_Assoc_List. For this reason we need to attach it
-- to the tree by setting its parent pointer to N. This parent point
-- will change in STEP 8 below.
Set_Parent (New_Assoc_List, N);
-- STEP 1: abstract type and null record verification
if Is_Abstract_Type (Typ) then
Error_Msg_N ("type of aggregate cannot be abstract", N);
end if;
if No (First_Entity (Typ)) and then Null_Record_Present (N) then
Set_Etype (N, Typ);
return;
elsif Present (First_Entity (Typ))
and then Null_Record_Present (N)
and then not Is_Tagged_Type (Typ)
then
Error_Msg_N ("record aggregate cannot be null", N);
return;
-- If the type has no components, then the aggregate should either
-- have "null record", or in Ada 2005 it could instead have a single
-- component association given by "others => <>". For Ada 95 we flag an
-- error at this point, but for Ada 2005 we proceed with checking the
-- associations below, which will catch the case where it's not an
-- aggregate with "others => <>". Note that the legality of a <>
-- aggregate for a null record type was established by AI05-016.
elsif No (First_Entity (Typ))
and then Ada_Version < Ada_2005
then
Error_Msg_N ("record aggregate must be null", N);
return;
end if;
-- STEP 2: Verify aggregate structure
Step_2 : declare
Selector_Name : Node_Id;
Bad_Aggregate : Boolean := False;
begin
if Present (Component_Associations (N)) then
Assoc := First (Component_Associations (N));
else
Assoc := Empty;
end if;
while Present (Assoc) loop
Selector_Name := First (Choices (Assoc));
while Present (Selector_Name) loop
if Nkind (Selector_Name) = N_Identifier then
null;
elsif Nkind (Selector_Name) = N_Others_Choice then
if Selector_Name /= First (Choices (Assoc))
or else Present (Next (Selector_Name))
then
Error_Msg_N
("OTHERS must appear alone in a choice list",
Selector_Name);
return;
elsif Present (Next (Assoc)) then
Error_Msg_N
("OTHERS must appear last in an aggregate",
Selector_Name);
return;
-- (Ada 2005): If this is an association with a box,
-- indicate that the association need not represent
-- any component.
elsif Box_Present (Assoc) then
Others_Box := True;
end if;
else
Error_Msg_N
("selector name should be identifier or OTHERS",
Selector_Name);
Bad_Aggregate := True;
end if;
Next (Selector_Name);
end loop;
Next (Assoc);
end loop;
if Bad_Aggregate then
return;
end if;
end Step_2;
-- STEP 3: Find discriminant Values
Step_3 : declare
Discrim : Entity_Id;
Missing_Discriminants : Boolean := False;
begin
if Present (Expressions (N)) then
Positional_Expr := First (Expressions (N));
else
Positional_Expr := Empty;
end if;
-- AI05-0115: if the ancestor part is a subtype mark, the ancestor
-- must not have unknown discriminants.
if Is_Derived_Type (Typ)
and then Has_Unknown_Discriminants (Root_Type (Typ))
and then Nkind (N) /= N_Extension_Aggregate
then
Error_Msg_NE
("aggregate not available for type& whose ancestor "
& "has unknown discriminants ", N, Typ);
end if;
if Has_Unknown_Discriminants (Typ)
and then Present (Underlying_Record_View (Typ))
then
Discrim := First_Discriminant (Underlying_Record_View (Typ));
elsif Has_Discriminants (Typ) then
Discrim := First_Discriminant (Typ);
else
Discrim := Empty;
end if;
-- First find the discriminant values in the positional components
while Present (Discrim) and then Present (Positional_Expr) loop
if Discr_Present (Discrim) then
Resolve_Aggr_Expr (Positional_Expr, Discrim);
-- Ada 2005 (AI-231)
if Ada_Version >= Ada_2005
and then Known_Null (Positional_Expr)
then
Check_Can_Never_Be_Null (Discrim, Positional_Expr);
end if;
Next (Positional_Expr);
end if;
if Present (Get_Value (Discrim, Component_Associations (N))) then
Error_Msg_NE
("more than one value supplied for discriminant&",
N, Discrim);
end if;
Next_Discriminant (Discrim);
end loop;
-- Find remaining discriminant values if any among named components
while Present (Discrim) loop
Expr := Get_Value (Discrim, Component_Associations (N), True);
if not Discr_Present (Discrim) then
if Present (Expr) then
Error_Msg_NE
("more than one value supplied for discriminant &",
N, Discrim);
end if;
elsif No (Expr) then
Error_Msg_NE
("no value supplied for discriminant &", N, Discrim);
Missing_Discriminants := True;
else
Resolve_Aggr_Expr (Expr, Discrim);
end if;
Next_Discriminant (Discrim);
end loop;
if Missing_Discriminants then
return;
end if;
-- At this point and until the beginning of STEP 6, New_Assoc_List
-- contains only the discriminants and their values.
end Step_3;
-- STEP 4: Set the Etype of the record aggregate
-- ??? This code is pretty much a copy of Sem_Ch3.Build_Subtype. That
-- routine should really be exported in sem_util or some such and used
-- in sem_ch3 and here rather than have a copy of the code which is a
-- maintenance nightmare.
-- ??? Performance WARNING. The current implementation creates a new
-- itype for all aggregates whose base type is discriminated. This means
-- that for record aggregates nested inside an array aggregate we will
-- create a new itype for each record aggregate if the array component
-- type has discriminants. For large aggregates this may be a problem.
-- What should be done in this case is to reuse itypes as much as
-- possible.
if Has_Discriminants (Typ)
or else (Has_Unknown_Discriminants (Typ)
and then Present (Underlying_Record_View (Typ)))
then
Build_Constrained_Itype : declare
Loc : constant Source_Ptr := Sloc (N);
Indic : Node_Id;
Subtyp_Decl : Node_Id;
Def_Id : Entity_Id;
C : constant List_Id := New_List;
begin
New_Assoc := First (New_Assoc_List);
while Present (New_Assoc) loop
Append (Duplicate_Subexpr (Expression (New_Assoc)), To => C);
Next (New_Assoc);
end loop;
if Has_Unknown_Discriminants (Typ)
and then Present (Underlying_Record_View (Typ))
then
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark =>
New_Occurrence_Of (Underlying_Record_View (Typ), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc, C));
else
Indic :=
Make_Subtype_Indication (Loc,
Subtype_Mark =>
New_Occurrence_Of (Base_Type (Typ), Loc),
Constraint =>
Make_Index_Or_Discriminant_Constraint (Loc, C));
end if;
Def_Id := Create_Itype (Ekind (Typ), N);
Subtyp_Decl :=
Make_Subtype_Declaration (Loc,
Defining_Identifier => Def_Id,
Subtype_Indication => Indic);
Set_Parent (Subtyp_Decl, Parent (N));
-- Itypes must be analyzed with checks off (see itypes.ads)
Analyze (Subtyp_Decl, Suppress => All_Checks);
Set_Etype (N, Def_Id);
Check_Static_Discriminated_Subtype
(Def_Id, Expression (First (New_Assoc_List)));
end Build_Constrained_Itype;
else
Set_Etype (N, Typ);
end if;
-- STEP 5: Get remaining components according to discriminant values
Step_5 : declare
Record_Def : Node_Id;
Parent_Typ : Entity_Id;
Root_Typ : Entity_Id;
Parent_Typ_List : Elist_Id;
Parent_Elmt : Elmt_Id;
Errors_Found : Boolean := False;
Dnode : Node_Id;
function Find_Private_Ancestor return Entity_Id;
-- AI05-0115: Find earlier ancestor in the derivation chain that is
-- derived from a private view. Whether the aggregate is legal
-- depends on the current visibility of the type as well as that
-- of the parent of the ancestor.
---------------------------
-- Find_Private_Ancestor --
---------------------------
function Find_Private_Ancestor return Entity_Id is
Par : Entity_Id;
begin
Par := Typ;
loop
if Has_Private_Ancestor (Par)
and then not Has_Private_Ancestor (Etype (Base_Type (Par)))
then
return Par;
elsif not Is_Derived_Type (Par) then
return Empty;
else
Par := Etype (Base_Type (Par));
end if;
end loop;
end Find_Private_Ancestor;
-- Start of processing for Step_5
begin
if Is_Derived_Type (Typ) and then Is_Tagged_Type (Typ) then
Parent_Typ_List := New_Elmt_List;
-- If this is an extension aggregate, the component list must
-- include all components that are not in the given ancestor type.
-- Otherwise, the component list must include components of all
-- ancestors, starting with the root.
if Nkind (N) = N_Extension_Aggregate then
Root_Typ := Base_Type (Etype (Ancestor_Part (N)));
else
-- AI05-0115: check legality of aggregate for type with
-- aa private ancestor.
Root_Typ := Root_Type (Typ);
if Has_Private_Ancestor (Typ) then
declare
Ancestor : constant Entity_Id :=
Find_Private_Ancestor;
Ancestor_Unit : constant Entity_Id :=
Cunit_Entity (Get_Source_Unit (Ancestor));
Parent_Unit : constant Entity_Id :=
Cunit_Entity
(Get_Source_Unit (Base_Type (Etype (Ancestor))));
begin
-- Check whether we are in a scope that has full view
-- over the private ancestor and its parent. This can
-- only happen if the derivation takes place in a child
-- unit of the unit that declares the parent, and we are
-- in the private part or body of that child unit, else
-- the aggregate is illegal.
if Is_Child_Unit (Ancestor_Unit)
and then Scope (Ancestor_Unit) = Parent_Unit
and then In_Open_Scopes (Scope (Ancestor))
and then
(In_Private_Part (Scope (Ancestor))
or else In_Package_Body (Scope (Ancestor)))
then
null;
else
Error_Msg_NE
("type of aggregate has private ancestor&!",
N, Root_Typ);
Error_Msg_N ("must use extension aggregate!", N);
return;
end if;
end;
end if;
Dnode := Declaration_Node (Base_Type (Root_Typ));
-- If we don't get a full declaration, then we have some error
-- which will get signalled later so skip this part. Otherwise
-- gather components of root that apply to the aggregate type.
-- We use the base type in case there is an applicable stored
-- constraint that renames the discriminants of the root.
if Nkind (Dnode) = N_Full_Type_Declaration then
Record_Def := Type_Definition (Dnode);
Gather_Components
(Base_Type (Typ),
Component_List (Record_Def),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
if Errors_Found then
Error_Msg_N
("discriminant controlling variant part is not static",
N);
return;
end if;
end if;
end if;
Parent_Typ := Base_Type (Typ);
while Parent_Typ /= Root_Typ loop
Prepend_Elmt (Parent_Typ, To => Parent_Typ_List);
Parent_Typ := Etype (Parent_Typ);
if Nkind (Parent (Base_Type (Parent_Typ))) =
N_Private_Type_Declaration
or else Nkind (Parent (Base_Type (Parent_Typ))) =
N_Private_Extension_Declaration
then
if Nkind (N) /= N_Extension_Aggregate then
Error_Msg_NE
("type of aggregate has private ancestor&!",
N, Parent_Typ);
Error_Msg_N ("must use extension aggregate!", N);
return;
elsif Parent_Typ /= Root_Typ then
Error_Msg_NE
("ancestor part of aggregate must be private type&",
Ancestor_Part (N), Parent_Typ);
return;
end if;
-- The current view of ancestor part may be a private type,
-- while the context type is always non-private.
elsif Is_Private_Type (Root_Typ)
and then Present (Full_View (Root_Typ))
and then Nkind (N) = N_Extension_Aggregate
then
exit when Base_Type (Full_View (Root_Typ)) = Parent_Typ;
end if;
end loop;
-- Now collect components from all other ancestors, beginning
-- with the current type. If the type has unknown discriminants
-- use the component list of the Underlying_Record_View, which
-- needs to be used for the subsequent expansion of the aggregate
-- into assignments.
Parent_Elmt := First_Elmt (Parent_Typ_List);
while Present (Parent_Elmt) loop
Parent_Typ := Node (Parent_Elmt);
if Has_Unknown_Discriminants (Parent_Typ)
and then Present (Underlying_Record_View (Typ))
then
Parent_Typ := Underlying_Record_View (Parent_Typ);
end if;
Record_Def := Type_Definition (Parent (Base_Type (Parent_Typ)));
Gather_Components (Empty,
Component_List (Record_Extension_Part (Record_Def)),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
Next_Elmt (Parent_Elmt);
end loop;
-- Typ is not a derived tagged type
else
Record_Def := Type_Definition (Parent (Base_Type (Typ)));
if Null_Present (Record_Def) then
null;
elsif not Has_Unknown_Discriminants (Typ) then
Gather_Components
(Base_Type (Typ),
Component_List (Record_Def),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
else
Gather_Components
(Base_Type (Underlying_Record_View (Typ)),
Component_List (Record_Def),
Governed_By => New_Assoc_List,
Into => Components,
Report_Errors => Errors_Found);
end if;
end if;
if Errors_Found then
return;
end if;
end Step_5;
-- STEP 6: Find component Values
Component := Empty;
Component_Elmt := First_Elmt (Components);
-- First scan the remaining positional associations in the aggregate.
-- Remember that at this point Positional_Expr contains the current
-- positional association if any is left after looking for discriminant
-- values in step 3.
while Present (Positional_Expr) and then Present (Component_Elmt) loop
Component := Node (Component_Elmt);
Resolve_Aggr_Expr (Positional_Expr, Component);
-- Ada 2005 (AI-231)
if Ada_Version >= Ada_2005 and then Known_Null (Positional_Expr) then
Check_Can_Never_Be_Null (Component, Positional_Expr);
end if;
if Present (Get_Value (Component, Component_Associations (N))) then
Error_Msg_NE
("more than one value supplied for Component &", N, Component);
end if;
Next (Positional_Expr);
Next_Elmt (Component_Elmt);
end loop;
if Present (Positional_Expr) then
Error_Msg_N
("too many components for record aggregate", Positional_Expr);
end if;
-- Now scan for the named arguments of the aggregate
while Present (Component_Elmt) loop
Component := Node (Component_Elmt);
Expr := Get_Value (Component, Component_Associations (N), True);
-- Note: The previous call to Get_Value sets the value of the
-- variable Is_Box_Present.
-- Ada 2005 (AI-287): Handle components with default initialization.
-- Note: This feature was originally added to Ada 2005 for limited
-- but it was finally allowed with any type.
if Is_Box_Present then
Check_Box_Component : declare
Ctyp : constant Entity_Id := Etype (Component);
begin
-- If there is a default expression for the aggregate, copy
-- it into a new association. This copy must modify the scopes
-- of internal types that may be attached to the expression
-- (e.g. index subtypes of arrays) because in general the type
-- declaration and the aggregate appear in different scopes,
-- and the backend requires the scope of the type to match the
-- point at which it is elaborated.
-- If the component has an initialization procedure (IP) we
-- pass the component to the expander, which will generate
-- the call to such IP.
-- If the component has discriminants, their values must
-- be taken from their subtype. This is indispensable for
-- constraints that are given by the current instance of an
-- enclosing type, to allow the expansion of the aggregate to
-- replace the reference to the current instance by the target
-- object of the aggregate.
if Present (Parent (Component))
and then
Nkind (Parent (Component)) = N_Component_Declaration
and then Present (Expression (Parent (Component)))
then
Expr :=
New_Copy_Tree_And_Copy_Dimensions
(Expression (Parent (Component)),
New_Scope => Current_Scope,
New_Sloc => Sloc (N));
Add_Association
(Component => Component,
Expr => Expr,
Assoc_List => New_Assoc_List);
Set_Has_Self_Reference (N);
-- A box-defaulted access component gets the value null. Also
-- included are components of private types whose underlying
-- type is an access type. In either case set the type of the
-- literal, for subsequent use in semantic checks.
elsif Present (Underlying_Type (Ctyp))
and then Is_Access_Type (Underlying_Type (Ctyp))
then
if not Is_Private_Type (Ctyp) then
Expr := Make_Null (Sloc (N));
Set_Etype (Expr, Ctyp);
Add_Association
(Component => Component,
Expr => Expr,
Assoc_List => New_Assoc_List);
-- If the component's type is private with an access type as
-- its underlying type then we have to create an unchecked
-- conversion to satisfy type checking.
else
declare
Qual_Null : constant Node_Id :=
Make_Qualified_Expression (Sloc (N),
Subtype_Mark =>
New_Occurrence_Of
(Underlying_Type (Ctyp), Sloc (N)),
Expression => Make_Null (Sloc (N)));
Convert_Null : constant Node_Id :=
Unchecked_Convert_To
(Ctyp, Qual_Null);
begin
Analyze_And_Resolve (Convert_Null, Ctyp);
Add_Association
(Component => Component,
Expr => Convert_Null,
Assoc_List => New_Assoc_List);
end;
end if;
-- Ada 2012: If component is scalar with default value, use it
elsif Is_Scalar_Type (Ctyp)
and then Has_Default_Aspect (Ctyp)
then
Add_Association
(Component => Component,
Expr => Default_Aspect_Value
(First_Subtype (Underlying_Type (Ctyp))),
Assoc_List => New_Assoc_List);
elsif Has_Non_Null_Base_Init_Proc (Ctyp)
or else not Expander_