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Diffstat (limited to 'gcc-4.9/gcc/ada/sem_aggr.adb')
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diff --git a/gcc-4.9/gcc/ada/sem_aggr.adb b/gcc-4.9/gcc/ada/sem_aggr.adb new file mode 100644 index 000000000..bb1794444 --- /dev/null +++ b/gcc-4.9/gcc/ada/sem_aggr.adb @@ -0,0 +1,4790 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ A G G R -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 1992-2013, 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 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. + + 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 Aggregate_Constraint_Checks + (Exp : Node_Id; + Check_Typ : Entity_Id); + -- Checks expression Exp against subtype Check_Typ. If Exp is an + -- aggregate and Check_Typ a constrained record type with discriminants, + -- we generate the appropriate discriminant checks. If Exp is an array + -- aggregate then emit the appropriate length checks. If Exp is a scalar + -- type, or a string literal, Exp is changed into Check_Typ'(Exp) to + -- ensure that range checks are performed at run time. + + 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. + + --------------------------------- + -- Aggregate_Constraint_Checks -- + --------------------------------- + + procedure Aggregate_Constraint_Checks + (Exp : Node_Id; + Check_Typ : Entity_Id) + is + Exp_Typ : constant Entity_Id := Etype (Exp); + + begin + if Raises_Constraint_Error (Exp) then + return; + end if; + + -- Ada 2005 (AI-230): Generate a conversion to an anonymous access + -- component's type to force the appropriate accessibility checks. + + -- Ada 2005 (AI-231): Generate conversion to the null-excluding + -- type to force the corresponding run-time check + + if Is_Access_Type (Check_Typ) + and then ((Is_Local_Anonymous_Access (Check_Typ)) + or else (Can_Never_Be_Null (Check_Typ) + and then not Can_Never_Be_Null (Exp_Typ))) + then + Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp))); + Analyze_And_Resolve (Exp, Check_Typ); + Check_Unset_Reference (Exp); + end if; + + -- This is really expansion activity, so make sure that expansion is + -- on and is allowed. In GNATprove mode, we also want check flags to + -- be added in the tree, so that the formal verification can rely on + -- those to be present. In GNATprove mode for formal verification, some + -- treatment typically only done during expansion needs to be performed + -- on the tree, but it should not be applied inside generics. Otherwise, + -- this breaks the name resolution mechanism for generic instances. + + if not Expander_Active + and (Inside_A_Generic or not Full_Analysis or not GNATprove_Mode) + then + return; + end if; + + -- First check if we have to insert discriminant checks + + if Has_Discriminants (Exp_Typ) then + Apply_Discriminant_Check (Exp, Check_Typ); + + -- Next emit length checks for array aggregates + + elsif Is_Array_Type (Exp_Typ) then + Apply_Length_Check (Exp, Check_Typ); + + -- Finally emit scalar and string checks. If we are dealing with a + -- scalar literal we need to check by hand because the Etype of + -- literals is not necessarily correct. + + elsif Is_Scalar_Type (Exp_Typ) + and then Compile_Time_Known_Value (Exp) + then + if Is_Out_Of_Range (Exp, Base_Type (Check_Typ)) then + Apply_Compile_Time_Constraint_Error + (Exp, "value not in range of}??", CE_Range_Check_Failed, + Ent => Base_Type (Check_Typ), + Typ => Base_Type (Check_Typ)); + + elsif Is_Out_Of_Range (Exp, Check_Typ) then + Apply_Compile_Time_Constraint_Error + (Exp, "value not in range of}??", CE_Range_Check_Failed, + Ent => Check_Typ, + Typ => Check_Typ); + + elsif not Range_Checks_Suppressed (Check_Typ) then + Apply_Scalar_Range_Check (Exp, Check_Typ); + end if; + + -- Verify that target type is also scalar, to prevent view anomalies + -- in instantiations. + + elsif (Is_Scalar_Type (Exp_Typ) + or else Nkind (Exp) = N_String_Literal) + and then Is_Scalar_Type (Check_Typ) + and then Exp_Typ /= Check_Typ + then + if Is_Entity_Name (Exp) + and then Ekind (Entity (Exp)) = E_Constant + then + -- If expression is a constant, it is worthwhile checking whether + -- it is a bound of the type. + + if (Is_Entity_Name (Type_Low_Bound (Check_Typ)) + and then Entity (Exp) = Entity (Type_Low_Bound (Check_Typ))) + or else (Is_Entity_Name (Type_High_Bound (Check_Typ)) + and then Entity (Exp) = Entity (Type_High_Bound (Check_Typ))) + then + return; + + else + Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp))); + Analyze_And_Resolve (Exp, Check_Typ); + Check_Unset_Reference (Exp); + end if; + else + Rewrite (Exp, Convert_To (Check_Typ, Relocate_Node (Exp))); + Analyze_And_Resolve (Exp, Check_Typ); + Check_Unset_Reference (Exp); + end if; + + end if; + end Aggregate_Constraint_Checks; + + ------------------------ + -- 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_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) + and then not In_Instance_Body + then + if 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_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_Restriction + ("array aggregate should have only OTHERS", N); + end if; + + elsif Is_Top_Level_Aggregate (N) then + Check_SPARK_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_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. + + 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_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. + + if Do_Range_Check (Expr) then + Set_Do_Range_Check (Expr, False); + 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; + pragma Warnings (Off, Discard); + + 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 the subtype has a static predicate, replace the + -- original choice with the list of individual values + -- covered by the predicate. + + if Present (Static_Predicate (E)) then + Delete_Choice := True; + + New_Cs := New_List; + P := First (Static_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); + + -- 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_Static_Expression (Choice) + or else (Nkind (Choice) = N_Range + and then Is_Static_Range (Choice))) + then + Check_SPARK_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 + Choice := Table (J).Lo; + + if Hi_Val + 1 = Lo_Val - 1 then + Error_Msg_N + ("missing index value in array aggregate!", + Choice); + else + Error_Msg_N + ("missing index values in array aggregate!", + Choice); + end if; + + Output_Bad_Choices + (Hi_Val + 1, Lo_Val - 1, Choice); + 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 not-known-at-compile-time values. + + -- 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; + + elsif Nkind_In (Anc, N_Aggregate, 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_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 + Assoc : Node_Id; + Expr : Node_Id := Empty; + Selector_Name : Node_Id; + + begin + Is_Box_Present := False; + + if Present (From) then + Assoc := First (From); + else + return Empty; + end if; + + 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 (Etype + (Compon)) + then + Error_Msg_N ("components in OTHERS choice must " & + "have same type", Selector_Name); + end if; + + Others_Etype := Etype (Compon); + + if Expander_Active then + 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. + + 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. + + if Do_Range_Check (Expr) then + Set_Do_Range_Check (Expr, False); + 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_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_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_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); + 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 + -- A type derived from an untagged private type whose full view + -- has discriminants is constructed as a record type but there + -- are no legal aggregates for it. + + if Is_Derived_Type (Typ) + and then Has_Private_Ancestor (Typ) + and then Nkind (N) /= N_Extension_Aggregate + then + Error_Msg_Node_2 := Base_Type (Etype (Typ)); + Error_Msg_NE + ("no aggregate available for type& derived from " + & "private type&", N, Typ); + return; + end if; + + 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_Active + then + if Is_Record_Type (Ctyp) + and then Has_Discriminants (Ctyp) + and then not Is_Private_Type (Ctyp) + then + -- We build a partially initialized aggregate with the + -- values of the discriminants and box initialization + -- for the rest, if other components are present. + + -- The type of the aggregate is the known subtype of + -- the component. The capture of discriminants must + -- be recursive because subcomponents may be constrained + -- (transitively) by discriminants of enclosing types. + -- For a private type with discriminants, a call to the + -- initialization procedure will be generated, and no + -- subaggregate is needed. + + Capture_Discriminants : declare + Loc : constant Source_Ptr := Sloc (N); + Expr : Node_Id; + + procedure Add_Discriminant_Values + (New_Aggr : Node_Id; + Assoc_List : List_Id); + -- The constraint to a component may be given by a + -- discriminant of the enclosing type, in which case + -- we have to retrieve its value, which is part of the + -- enclosing aggregate. Assoc_List provides the + -- discriminant associations of the current type or + -- of some enclosing record. + + procedure Propagate_Discriminants + (Aggr : Node_Id; + Assoc_List : List_Id); + -- Nested components may themselves be discriminated + -- types constrained by outer discriminants, whose + -- values must be captured before the aggregate is + -- expanded into assignments. + + ----------------------------- + -- Add_Discriminant_Values -- + ----------------------------- + + procedure Add_Discriminant_Values + (New_Aggr : Node_Id; + Assoc_List : List_Id) + is + Assoc : Node_Id; + Discr : Entity_Id; + Discr_Elmt : Elmt_Id; + Discr_Val : Node_Id; + Val : Entity_Id; + + begin + Discr := First_Discriminant (Etype (New_Aggr)); + Discr_Elmt := + First_Elmt + (Discriminant_Constraint (Etype (New_Aggr))); + while Present (Discr_Elmt) loop + Discr_Val := Node (Discr_Elmt); + + -- If the constraint is given by a discriminant + -- it is a discriminant of an enclosing record, + -- and its value has already been placed in the + -- association list. + + if Is_Entity_Name (Discr_Val) + and then + Ekind (Entity (Discr_Val)) = E_Discriminant + then + Val := Entity (Discr_Val); + + Assoc := First (Assoc_List); + while Present (Assoc) loop + if Present + (Entity (First (Choices (Assoc)))) + and then + Entity (First (Choices (Assoc))) + = Val + then + Discr_Val := Expression (Assoc); + exit; + end if; + Next (Assoc); + end loop; + end if; + + Add_Association + (Discr, New_Copy_Tree (Discr_Val), + Component_Associations (New_Aggr)); + + -- If the discriminant constraint is a current + -- instance, mark the current aggregate so that + -- the self-reference can be expanded later. + + if Nkind (Discr_Val) = N_Attribute_Reference + and then Is_Entity_Name (Prefix (Discr_Val)) + and then Is_Type (Entity (Prefix (Discr_Val))) + and then Etype (N) = + Entity (Prefix (Discr_Val)) + then + Set_Has_Self_Reference (N); + end if; + + Next_Elmt (Discr_Elmt); + Next_Discriminant (Discr); + end loop; + end Add_Discriminant_Values; + + ------------------------------ + -- Propagate_Discriminants -- + ------------------------------ + + procedure Propagate_Discriminants + (Aggr : Node_Id; + Assoc_List : List_Id) + is + Aggr_Type : constant Entity_Id := + Base_Type (Etype (Aggr)); + Def_Node : constant Node_Id := + Type_Definition + (Declaration_Node (Aggr_Type)); + + Comp : Node_Id; + Comp_Elmt : Elmt_Id; + Components : constant Elist_Id := New_Elmt_List; + Needs_Box : Boolean := False; + Errors : Boolean; + + procedure Process_Component (Comp : Entity_Id); + -- Add one component with a box association to the + -- inner aggregate, and recurse if component is + -- itself composite. + + ------------------------ + -- Process_Component -- + ------------------------ + + procedure Process_Component (Comp : Entity_Id) is + T : constant Entity_Id := Etype (Comp); + New_Aggr : Node_Id; + + begin + if Is_Record_Type (T) + and then Has_Discriminants (T) + then + New_Aggr := + Make_Aggregate (Loc, New_List, New_List); + Set_Etype (New_Aggr, T); + Add_Association + (Comp, New_Aggr, + Component_Associations (Aggr)); + + -- Collect discriminant values and recurse + + Add_Discriminant_Values + (New_Aggr, Assoc_List); + Propagate_Discriminants + (New_Aggr, Assoc_List); + + else + Needs_Box := True; + end if; + end Process_Component; + + -- Start of processing for Propagate_Discriminants + + begin + -- The component type may be a variant type, so + -- collect the components that are ruled by the + -- known values of the discriminants. Their values + -- have already been inserted into the component + -- list of the current aggregate. + + if Nkind (Def_Node) = N_Record_Definition + and then + Present (Component_List (Def_Node)) + and then + Present + (Variant_Part (Component_List (Def_Node))) + then + Gather_Components (Aggr_Type, + Component_List (Def_Node), + Governed_By => Component_Associations (Aggr), + Into => Components, + Report_Errors => Errors); + + Comp_Elmt := First_Elmt (Components); + while Present (Comp_Elmt) loop + if + Ekind (Node (Comp_Elmt)) /= E_Discriminant + then + Process_Component (Node (Comp_Elmt)); + end if; + + Next_Elmt (Comp_Elmt); + end loop; + + -- No variant part, iterate over all components + + else + Comp := First_Component (Etype (Aggr)); + while Present (Comp) loop + Process_Component (Comp); + Next_Component (Comp); + end loop; + end if; + + if Needs_Box then + Append + (Make_Component_Association (Loc, + Choices => + New_List (Make_Others_Choice (Loc)), + Expression => Empty, + Box_Present => True), + Component_Associations (Aggr)); + end if; + end Propagate_Discriminants; + + -- Start of processing for Capture_Discriminants + + begin + Expr := Make_Aggregate (Loc, New_List, New_List); + Set_Etype (Expr, Ctyp); + + -- If the enclosing type has discriminants, they have + -- been collected in the aggregate earlier, and they + -- may appear as constraints of subcomponents. + + -- Similarly if this component has discriminants, they + -- might in turn be propagated to their components. + + if Has_Discriminants (Typ) then + Add_Discriminant_Values (Expr, New_Assoc_List); + Propagate_Discriminants (Expr, New_Assoc_List); + + elsif Has_Discriminants (Ctyp) then + Add_Discriminant_Values + (Expr, Component_Associations (Expr)); + Propagate_Discriminants + (Expr, Component_Associations (Expr)); + + else + declare + Comp : Entity_Id; + + begin + -- If the type has additional components, create + -- an OTHERS box association for them. + + Comp := First_Component (Ctyp); + while Present (Comp) loop + if Ekind (Comp) = E_Component then + if not Is_Record_Type (Etype (Comp)) then + Append + (Make_Component_Association (Loc, + Choices => + New_List + (Make_Others_Choice (Loc)), + Expression => Empty, + Box_Present => True), + Component_Associations (Expr)); + end if; + exit; + end if; + + Next_Component (Comp); + end loop; + end; + end if; + + Add_Association + (Component => Component, + Expr => Expr, + Assoc_List => New_Assoc_List); + end Capture_Discriminants; + + else + Add_Association + (Component => Component, + Expr => Empty, + Assoc_List => New_Assoc_List, + Is_Box_Present => True); + end if; + + -- Otherwise we only need to resolve the expression if the + -- component has partially initialized values (required to + -- expand the corresponding assignments and run-time checks). + + elsif Present (Expr) + and then Is_Partially_Initialized_Type (Ctyp) + then + Resolve_Aggr_Expr (Expr, Component); + end if; + end Check_Box_Component; + + elsif No (Expr) then + + -- Ignore hidden components associated with the position of the + -- interface tags: these are initialized dynamically. + + if not Present (Related_Type (Component)) then + Error_Msg_NE + ("no value supplied for component &!", N, Component); + end if; + + else + Resolve_Aggr_Expr (Expr, Component); + end if; + + Next_Elmt (Component_Elmt); + end loop; + + -- STEP 7: check for invalid components + check type in choice list + + Step_7 : declare + Selectr : Node_Id; + -- Selector name + + Typech : Entity_Id; + -- Type of first component in choice list + + begin + if Present (Component_Associations (N)) then + Assoc := First (Component_Associations (N)); + else + Assoc := Empty; + end if; + + Verification : while Present (Assoc) loop + Selectr := First (Choices (Assoc)); + Typech := Empty; + + if Nkind (Selectr) = N_Others_Choice then + + -- Ada 2005 (AI-287): others choice may have expression or box + + if No (Others_Etype) + and then not Others_Box + then + Error_Msg_N + ("OTHERS must represent at least one component", Selectr); + end if; + + exit Verification; + end if; + + while Present (Selectr) loop + New_Assoc := First (New_Assoc_List); + while Present (New_Assoc) loop + Component := First (Choices (New_Assoc)); + + if Chars (Selectr) = Chars (Component) then + if Style_Check then + Check_Identifier (Selectr, Entity (Component)); + end if; + + exit; + end if; + + Next (New_Assoc); + end loop; + + -- If no association, this is not a legal component of the type + -- in question, unless its association is provided with a box. + + if No (New_Assoc) then + if Box_Present (Parent (Selectr)) then + + -- This may still be a bogus component with a box. Scan + -- list of components to verify that a component with + -- that name exists. + + declare + C : Entity_Id; + + begin + C := First_Component (Typ); + while Present (C) loop + if Chars (C) = Chars (Selectr) then + + -- If the context is an extension aggregate, + -- the component must not be inherited from + -- the ancestor part of the aggregate. + + if Nkind (N) /= N_Extension_Aggregate + or else + Scope (Original_Record_Component (C)) /= + Etype (Ancestor_Part (N)) + then + exit; + end if; + end if; + + Next_Component (C); + end loop; + + if No (C) then + Error_Msg_Node_2 := Typ; + Error_Msg_N ("& is not a component of}", Selectr); + end if; + end; + + elsif Chars (Selectr) /= Name_uTag + and then Chars (Selectr) /= Name_uParent + then + if not Has_Discriminants (Typ) then + Error_Msg_Node_2 := Typ; + Error_Msg_N ("& is not a component of}", Selectr); + else + Error_Msg_N + ("& is not a component of the aggregate subtype", + Selectr); + end if; + + Check_Misspelled_Component (Components, Selectr); + end if; + + elsif No (Typech) then + Typech := Base_Type (Etype (Component)); + + -- AI05-0199: In Ada 2012, several components of anonymous + -- access types can appear in a choice list, as long as the + -- designated types match. + + elsif Typech /= Base_Type (Etype (Component)) then + if Ada_Version >= Ada_2012 + and then Ekind (Typech) = E_Anonymous_Access_Type + and then + Ekind (Etype (Component)) = E_Anonymous_Access_Type + and then Base_Type (Designated_Type (Typech)) = + Base_Type (Designated_Type (Etype (Component))) + and then + Subtypes_Statically_Match (Typech, (Etype (Component))) + then + null; + + elsif not Box_Present (Parent (Selectr)) then + Error_Msg_N + ("components in choice list must have same type", + Selectr); + end if; + end if; + + Next (Selectr); + end loop; + + Next (Assoc); + end loop Verification; + end Step_7; + + -- STEP 8: replace the original aggregate + + Step_8 : declare + New_Aggregate : constant Node_Id := New_Copy (N); + + begin + Set_Expressions (New_Aggregate, No_List); + Set_Etype (New_Aggregate, Etype (N)); + Set_Component_Associations (New_Aggregate, New_Assoc_List); + + Rewrite (N, New_Aggregate); + end Step_8; + + -- Check the dimensions of the components in the record aggregate + + Analyze_Dimension_Extension_Or_Record_Aggregate (N); + end Resolve_Record_Aggregate; + + ----------------------------- + -- Check_Can_Never_Be_Null -- + ----------------------------- + + procedure Check_Can_Never_Be_Null (Typ : Entity_Id; Expr : Node_Id) is + Comp_Typ : Entity_Id; + + begin + pragma Assert + (Ada_Version >= Ada_2005 + and then Present (Expr) + and then Known_Null (Expr)); + + case Ekind (Typ) is + when E_Array_Type => + Comp_Typ := Component_Type (Typ); + + when E_Component | + E_Discriminant => + Comp_Typ := Etype (Typ); + + when others => + return; + end case; + + if Can_Never_Be_Null (Comp_Typ) then + + -- Here we know we have a constraint error. Note that we do not use + -- Apply_Compile_Time_Constraint_Error here to the Expr, which might + -- seem the more natural approach. That's because in some cases the + -- components are rewritten, and the replacement would be missed. + -- We do not mark the whole aggregate as raising a constraint error, + -- because the association may be a null array range. + + Error_Msg_N + ("(Ada 2005) null not allowed in null-excluding component??", Expr); + Error_Msg_N + ("\Constraint_Error will be raised at run time?", Expr); + + Rewrite (Expr, + Make_Raise_Constraint_Error + (Sloc (Expr), Reason => CE_Access_Check_Failed)); + Set_Etype (Expr, Comp_Typ); + Set_Analyzed (Expr); + end if; + end Check_Can_Never_Be_Null; + + --------------------- + -- Sort_Case_Table -- + --------------------- + + procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is + U : constant Int := Case_Table'Last; + K : Int; + J : Int; + T : Case_Bounds; + + begin + K := 1; + while K < U loop + T := Case_Table (K + 1); + + J := K + 1; + while J > 1 + and then Expr_Value (Case_Table (J - 1).Lo) > Expr_Value (T.Lo) + loop + Case_Table (J) := Case_Table (J - 1); + J := J - 1; + end loop; + + Case_Table (J) := T; + K := K + 1; + end loop; + end Sort_Case_Table; + +end Sem_Aggr; |