X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fada%2Fsem_aggr.adb;h=993235210bba9983b74836808a32719b714c83ef;hb=e3a07cda8df51224d900667a50dc87bfffde1fa9;hp=21d620716f0437869de348f692a868a5bdc36e1e;hpb=521e4f857cbe98c35d2522b42680a70cfbab96bc;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/ada/sem_aggr.adb b/gcc/ada/sem_aggr.adb index 21d620716f0..993235210bb 100644 --- a/gcc/ada/sem_aggr.adb +++ b/gcc/ada/sem_aggr.adb @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2008, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2012, 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- -- @@ -28,6 +28,7 @@ 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; @@ -39,9 +40,12 @@ 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_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; @@ -52,6 +56,7 @@ 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; @@ -94,6 +99,15 @@ package body Sem_Aggr is -- 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 -- ------------------------------------------------------ @@ -133,8 +147,8 @@ package body Sem_Aggr is -- 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. + -- 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 @@ -142,31 +156,29 @@ package body Sem_Aggr is -- 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. + -- 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. + -- 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. + -- 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 @@ -175,41 +187,40 @@ package body Sem_Aggr is -- 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. + -- 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. + -- 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. + -- 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. + -- 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. + (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. + -- 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 -- @@ -414,6 +425,22 @@ package body Sem_Aggr is 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. @@ -486,20 +513,6 @@ package body Sem_Aggr is Check_Unset_Reference (Exp); 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 - - elsif 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; end Aggregate_Constraint_Checks; @@ -508,9 +521,8 @@ package body Sem_Aggr is ------------------------ function Array_Aggr_Subtype - (N : Node_Id; - Typ : Entity_Id) - return Entity_Id + (N : Node_Id; + Typ : Entity_Id) return Entity_Id is Aggr_Dimension : constant Pos := Number_Dimensions (Typ); -- Number of aggregate index dimensions @@ -525,10 +537,11 @@ package body Sem_Aggr is 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 the constrained N_Range - -- nodes corresponding to each index dimension of our aggregate itype. - -- These N_Range nodes are collected in Aggr_Range above. + -- 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 @@ -551,6 +564,9 @@ package body Sem_Aggr is 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. @@ -568,7 +584,7 @@ package body Sem_Aggr is Set_Raises_Constraint_Error (N); Error_Msg_N ("sub-aggregate low bound mismatch?", N); Error_Msg_N - ("\Constraint_Error will be raised at run-time?", N); + ("\Constraint_Error will be raised at run time?", N); end if; end if; @@ -582,7 +598,7 @@ package body Sem_Aggr is Set_Raises_Constraint_Error (N); Error_Msg_N ("sub-aggregate high bound mismatch?", N); Error_Msg_N - ("\Constraint_Error will be raised at run-time?", N); + ("\Constraint_Error will be raised at run time?", N); end if; end if; end if; @@ -617,7 +633,7 @@ package body Sem_Aggr is -- Array_Aggr_Subtype variables Itype : Entity_Id; - -- the final itype of the overall aggregate + -- The final itype of the overall aggregate Index_Constraints : constant List_Id := New_List; -- The list of index constraints of the aggregate itype @@ -625,13 +641,13 @@ package body Sem_Aggr is -- 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. + -- 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 indices of our aggregate itype + -- Build the list of constrained indexes of our aggregate itype for J in 1 .. Aggr_Dimension loop Create_Index : declare @@ -671,13 +687,13 @@ package body Sem_Aggr is 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)); + 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); @@ -687,22 +703,23 @@ package body Sem_Aggr is 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. Subse- - -- quent checks in exp_aggr verify that type is not packed, etc. + -- 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. + -- 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 + if Is_Packed (Itype) + and then not In_Spec_Expression and then Expander_Active then Freeze_Itype (Itype, N); @@ -716,8 +733,8 @@ package body Sem_Aggr is -------------------------------- procedure Check_Misspelled_Component - (Elements : Elist_Id; - Component : Node_Id) + (Elements : Elist_Id; + Component : Node_Id) is Max_Suggestions : constant := 2; @@ -727,11 +744,10 @@ package body Sem_Aggr is 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 analysis there are one or two (not more!) possible - -- misspellings, these misspellings will be suggested as - -- possible correction. + -- 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 @@ -756,12 +772,12 @@ package body Sem_Aggr is -- Report at most two suggestions if Nr_Of_Suggestions = 1 then - Error_Msg_NE + 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 + Error_Msg_NE -- CODEFIX ("\possible misspelling of& or&", Component, Suggestion_1); end if; end Check_Misspelled_Component; @@ -776,13 +792,50 @@ package body Sem_Aggr is and then Comes_From_Source (Expr) and then not In_Instance_Body then - if not OK_For_Limited_Init (Expr) 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 -- ---------------------------------------- @@ -843,6 +896,29 @@ package body Sem_Aggr is 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 -- -------------------------------- @@ -871,7 +947,7 @@ package body Sem_Aggr is Append_To (Exprs, C_Node); P := P + 1; - -- something special for wide strings ??? + -- Something special for wide strings??? end loop; New_N := Make_Aggregate (Loc, Expressions => Exprs); @@ -886,17 +962,87 @@ package body Sem_Aggr is ----------------------- procedure Resolve_Aggregate (N : Node_Id; Typ : Entity_Id) is - Pkind : constant Node_Kind := Nkind (Parent (N)); + 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 revolution. + + 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. + -- 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) @@ -907,7 +1053,14 @@ package body Sem_Aggr is -- Ada 2005 (AI-287): Limited aggregates allowed - if Is_Limited_Type (Typ) and then Ada_Version < Ada_05 then + -- 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); @@ -931,10 +1084,10 @@ package body Sem_Aggr is -- 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. + -- 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)) @@ -964,8 +1117,7 @@ package body Sem_Aggr is Next (Expr); end loop; - Rewrite (N, - Make_String_Literal (Sloc (N), End_String)); + Rewrite (N, Make_String_Literal (Loc, End_String)); Analyze_And_Resolve (N, Typ); return; @@ -979,24 +1131,26 @@ package body Sem_Aggr is 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. + -- 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 + -- 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. + -- 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. + -- 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 @@ -1004,23 +1158,24 @@ package body Sem_Aggr is -- 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 Is_Constrained (Typ) and then - (Pkind = N_Assignment_Statement or else - 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) + 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 @@ -1040,6 +1195,7 @@ package body Sem_Aggr is Index_Constr => First_Index (Typ), Component_Typ => Component_Type (Typ), Others_Allowed => True); + else Aggr_Resolved := Resolve_Array_Aggregate @@ -1051,7 +1207,19 @@ package body Sem_Aggr is 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; @@ -1061,7 +1229,7 @@ package body Sem_Aggr is elsif Is_Private_Type (Typ) and then Present (Full_View (Typ)) - and then In_Inlined_Body + and then (In_Inlined_Body or In_Instance_Body) and then Is_Composite_Type (Full_View (Typ)) then Resolve (N, Full_View (Typ)); @@ -1070,16 +1238,15 @@ package body Sem_Aggr is 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 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 (Sloc (N), - Reason => CE_Range_Check_Failed)); + Make_Raise_Constraint_Error (Loc, Reason => CE_Range_Check_Failed)); Set_Raises_Constraint_Error (N); Set_Etype (N, Aggr_Subtyp); Set_Analyzed (N); @@ -1105,13 +1272,13 @@ package body Sem_Aggr is 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 + -- 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 + -- 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. @@ -1119,18 +1286,18 @@ package body Sem_Aggr is -- analyzed expression. procedure Check_Bound (BH : Node_Id; AH : in out Node_Id); - -- Checks that AH (the upper bound of an array aggregate) is <= 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. + -- 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. + -- 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. + -- 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 @@ -1145,11 +1312,14 @@ package body Sem_Aggr is 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. + -- 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 -- @@ -1198,8 +1368,8 @@ package body Sem_Aggr is 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)); + 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) @@ -1223,6 +1393,30 @@ package body Sem_Aggr is Prefix => New_Reference_To (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_Reference_To (Index_Typ, Loc), + Constant_Present => True, + Expression => Relocate_Node (Expr))); + + Expr := New_Reference_To (Def_Id, Loc); + end; + end if; end if; return Expr; @@ -1246,10 +1440,10 @@ package body Sem_Aggr is if OK_BH and then OK_AH and then Val_BH < Val_AH then Set_Raises_Constraint_Error (N); Error_Msg_N ("upper bound out of range?", AH); - Error_Msg_N ("\Constraint_Error will be raised at run-time?", AH); + Error_Msg_N ("\Constraint_Error will be raised at run time?", AH); -- You need to set AH to BH or else in the case of enumerations - -- indices we will not be able to resolve the aggregate bounds. + -- indexes we will not be able to resolve the aggregate bounds. AH := Duplicate_Subexpr (BH); end if; @@ -1289,13 +1483,13 @@ package body Sem_Aggr is if OK_L and then Val_L > Val_AL then Set_Raises_Constraint_Error (N); Error_Msg_N ("lower bound of aggregate out of range?", N); - Error_Msg_N ("\Constraint_Error will be raised at run-time?", N); + Error_Msg_N ("\Constraint_Error will be raised at run time?", N); end if; if OK_H and then Val_H < Val_AH then Set_Raises_Constraint_Error (N); Error_Msg_N ("upper bound of aggregate out of range?", N); - Error_Msg_N ("\Constraint_Error will be raised at run-time?", N); + Error_Msg_N ("\Constraint_Error will be raised at run time?", N); end if; end Check_Bounds; @@ -1335,7 +1529,7 @@ package body Sem_Aggr is if Range_Len < Len then Set_Raises_Constraint_Error (N); Error_Msg_N ("too many elements?", N); - Error_Msg_N ("\Constraint_Error will be raised at run-time?", N); + Error_Msg_N ("\Constraint_Error will be raised at run time?", N); end if; end Check_Length; @@ -1402,6 +1596,14 @@ package body Sem_Aggr is -- 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). @@ -1430,10 +1632,27 @@ package body Sem_Aggr is 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. @@ -1443,19 +1662,42 @@ package body Sem_Aggr is Resolution_OK := Resolve_Array_Aggregate (Expr, Nxt_Ind, Nxt_Ind_Constr, Component_Typ, Others_Allowed); - -- Do not resolve the expressions of discrete or others choices - -- unless the expression covers a single component, or the expander - -- is inactive. + else + + -- If it's "... => <>", nothing to resolve - elsif 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); + 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 Alfa 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 Full_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) @@ -1464,6 +1706,14 @@ package body Sem_Aggr is 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; @@ -1501,6 +1751,15 @@ package body Sem_Aggr is -- 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 @@ -1566,6 +1825,31 @@ package body Sem_Aggr is return Failure; end if; + if Others_Present + and then Nkind (Parent (N)) /= N_Component_Association + and then No (Expressions (N)) + and then + Nkind (First (Choices (First (Component_Associations (N))))) + = N_Others_Choice + and then Is_Elementary_Type (Component_Typ) + and then False + then + declare + Assoc : constant Node_Id := First (Component_Associations (N)); + begin + Rewrite (Assoc, + Make_Component_Association (Loc, + Choices => + New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Index_Typ, Loc), + Attribute_Name => Name_Range)), + Expression => Relocate_Node (Expression (Assoc)))); + return Resolve_Array_Aggregate + (N, Index, Index_Constr, Component_Typ, Others_Allowed); + end; + end if; + -- Protect against cascaded errors if Etype (Index_Typ) = Any_Type then @@ -1607,8 +1891,11 @@ package body Sem_Aggr is -- discrete association Prev_Nb_Discrete_Choices : Nat; - -- Used to keep track of the number of discrete choices - -- in the current association. + -- 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 begin -- STEP 2 (A): Check discrete choices validity @@ -1654,12 +1941,29 @@ package body Sem_Aggr is 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 performed when we check - -- that the bounds of the array aggregate are within - -- range. + -- 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 @@ -1712,34 +2016,94 @@ package body Sem_Aggr is -- Ada 2005 (AI-231) - if Ada_Version >= Ada_05 + if Ada_Version >= Ada_2005 and then Known_Null (Expression (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 + -- 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. + -- 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. - null; + 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. Sort them and check that they are contiguous + -- static. Sort them and check that they are contiguous. if Nb_Discrete_Choices > 1 then Sort_Case_Table (Table); @@ -1868,6 +2232,14 @@ package body Sem_Aggr is 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); @@ -1877,7 +2249,7 @@ package body Sem_Aggr is Ent : Entity_Id; begin - -- Warning case one, missing values at start/end. Only + -- 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)) @@ -1956,7 +2328,7 @@ package body Sem_Aggr is -- Ada 2005 (AI-231) - if Ada_Version >= Ada_05 + if Ada_Version >= Ada_2005 and then Known_Null (Expr) then Check_Can_Never_Be_Null (Etype (N), Expr); @@ -1966,6 +2338,15 @@ package body Sem_Aggr is 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; @@ -1974,27 +2355,57 @@ package body Sem_Aggr is -- Ada 2005 (AI-231) - if Ada_Version >= Ada_05 + 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 + -- 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. + -- 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. - null; + 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; @@ -2049,7 +2460,7 @@ package body Sem_Aggr is -- 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 insure it will get + -- 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 @@ -2060,6 +2471,16 @@ package body Sem_Aggr is 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)); @@ -2085,20 +2506,20 @@ package body Sem_Aggr is -- 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 + -- 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. + -- 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. + -- 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); @@ -2108,8 +2529,8 @@ package body Sem_Aggr is 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). + -- 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 @@ -2134,9 +2555,7 @@ package body Sem_Aggr is then return True; - elsif - Nkind (Anc) = N_Qualified_Expression - then + elsif Nkind (Anc) = N_Qualified_Expression then return Valid_Limited_Ancestor (Expression (Anc)); else @@ -2153,26 +2572,69 @@ package body Sem_Aggr is begin Imm_Type := Base_Type (Typ); - while Is_Derived_Type (Imm_Type) - and then Etype (Imm_Type) /= Base_Type (A_Type) - loop - Imm_Type := Etype (Base_Type (Imm_Type)); + 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 not Is_Derived_Type (Base_Type (Typ)) - or else Etype (Imm_Type) /= Base_Type (A_Type) - then - Error_Msg_NE ("expect ancestor type of &", A, Typ); - return False; - else - return True; - end if; + -- 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); @@ -2182,7 +2644,7 @@ package body Sem_Aggr is -- Ada 2005 (AI-287): Limited aggregates are allowed - if Ada_Version < Ada_05 then + if Ada_Version < Ada_2005 then Error_Msg_N ("aggregate type cannot be limited", N); Explain_Limited_Type (Typ, N); return; @@ -2219,8 +2681,11 @@ package body Sem_Aggr is 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 not Is_Limited_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); @@ -2234,8 +2699,13 @@ package body Sem_Aggr is end loop; if A_Type = Any_Type then - Error_Msg_N - ("ancestor part must be non-limited tagged type", A); + 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; @@ -2248,18 +2718,61 @@ package body Sem_Aggr is Check_Unset_Reference (A); Check_Non_Static_Context (A); - if Is_Class_Wide_Type (Etype (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 - -- required components of the extension part. + -- 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 ACT query to the ARG after this test was added. + -- 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 @@ -2286,16 +2799,16 @@ package body Sem_Aggr is 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. + -- 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. - -- Please 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. + -- 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 @@ -2306,7 +2819,7 @@ package body Sem_Aggr is -- (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 + -- This variable is updated as a side effect of function Get_Value. Is_Box_Present : Boolean := False; Others_Box : Boolean := False; @@ -2320,40 +2833,48 @@ package body Sem_Aggr is 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 new association - -- list New_Assoc_List being built. + -- 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 the - -- N's aggregate part. Also, in this case, the routine appends to - -- New_Assoc_List Discr the discriminant value specified in the ancestor - -- part. + -- 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, the - -- following 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. + -- 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. + -- An error message is emitted if the components taking their value from + -- the others choice do not have same type. procedure Resolve_Aggr_Expr (Expr : Node_Id; Component : Node_Id); -- Analyzes and resolves expression Expr against the Etype of the @@ -2370,19 +2891,30 @@ package body Sem_Aggr is 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 - Append (New_Occurrence_Of (Component, Sloc (Expr)), Choice_List); + -- 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 (Sloc (Expr), + Make_Component_Association (Loc, Choices => Choice_List, Expression => Expr, Box_Present => Is_Box_Present); - Append (New_Assoc, New_Assoc_List); + Append (New_Assoc, Assoc_List); end Add_Association; ------------------- @@ -2395,6 +2927,7 @@ package body Sem_Aggr is Loc : Source_Ptr; Ancestor : Node_Id; + Comp_Assoc : Node_Id; Discr_Expr : Node_Id; Ancestor_Typ : Entity_Id; @@ -2409,10 +2942,35 @@ package body Sem_Aggr is 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)); @@ -2442,7 +3000,7 @@ package body Sem_Aggr is D := First_Discriminant (Ancestor_Typ); while Present (D) loop - -- If Ancestor has already specified Disc value than insert its + -- If Ancestor has already specified Disc value then insert its -- value in the final aggregate. if Original_Record_Component (D) = Orig_Discr then @@ -2456,6 +3014,7 @@ package body Sem_Aggr is end if; Resolve_Aggr_Expr (Discr_Expr, Discr); + Set_Inherited_Discriminant (Last (New_Assoc_List)); return False; end if; @@ -2549,7 +3108,7 @@ package body Sem_Aggr is -- Ada 2005 (AI-231) - if Ada_Version >= Ada_05 + if Ada_Version >= Ada_2005 and then Known_Null (Expression (Assoc)) then Check_Can_Never_Be_Null (Compon, Expression (Assoc)); @@ -2575,6 +3134,13 @@ package body Sem_Aggr is Expr := New_Copy_Tree (Expression (Parent (Compon))); + -- 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 Expr; + else if Present (Next (Selector_Name)) then Expr := New_Copy_Tree (Expression (Assoc)); @@ -2583,7 +3149,7 @@ package body Sem_Aggr is end if; end if; - Generate_Reference (Compon, Selector_Name); + Generate_Reference (Compon, Selector_Name, 'm'); else Error_Msg_NE @@ -2619,14 +3185,18 @@ package body Sem_Aggr is -- 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 the new association list. + 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); @@ -2639,7 +3209,7 @@ package body Sem_Aggr is and then Has_Expansion_Delayed (Expression (Expr))); end Has_Expansion_Delayed; - -- Start of processing for Resolve_Aggr_Expr + -- Start of processing for Resolve_Aggr_Expr begin -- If the type of the component is elementary or the type of the @@ -2726,24 +3296,84 @@ package body Sem_Aggr is 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 - Add_Association (New_C, Relocate_Node (Expr)); + Add_Association (New_C, Relocate_Node (Expr), New_Assoc_List); else - Add_Association (New_C, Expr); + Add_Association (New_C, Expr, New_Assoc_List); end if; 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 @@ -2768,7 +3398,17 @@ package body Sem_Aggr is Error_Msg_N ("record aggregate cannot be null", N); return; - elsif No (First_Entity (Typ)) then + -- 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; @@ -2796,16 +3436,18 @@ package body Sem_Aggr is 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); + 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); + Error_Msg_N + ("OTHERS must appear last in an aggregate", + Selector_Name); return; - -- (Ada2005): If this is an association with a box, + -- (Ada 2005): If this is an association with a box, -- indicate that the association need not represent -- any component. @@ -2844,7 +3486,23 @@ package body Sem_Aggr is Positional_Expr := Empty; end if; - if Has_Discriminants (Typ) then + -- AI05-0115: if the ancestor part is a subtype mark, the ancestor + -- must npt 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; @@ -2858,7 +3516,7 @@ package body Sem_Aggr is -- Ada 2005 (AI-231) - if Ada_Version >= Ada_05 + if Ada_Version >= Ada_2005 and then Known_Null (Positional_Expr) then Check_Can_Never_Be_Null (Discrim, Positional_Expr); @@ -2876,7 +3534,7 @@ package body Sem_Aggr is Next_Discriminant (Discrim); end loop; - -- Find remaining discriminant values, if any, among named components + -- Find remaining discriminant values if any among named components while Present (Discrim) loop Expr := Get_Value (Discrim, Component_Associations (N), True); @@ -2917,14 +3575,17 @@ package body Sem_Aggr is -- 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) then + -- 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; @@ -2940,10 +3601,23 @@ package body Sem_Aggr is Next (New_Assoc); end loop; - Indic := - Make_Subtype_Indication (Loc, - Subtype_Mark => New_Occurrence_Of (Base_Type (Typ), Loc), - Constraint => Make_Index_Or_Discriminant_Constraint (Loc, C)); + 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); @@ -2977,38 +3651,96 @@ package body Sem_Aggr is 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; + 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. + -- 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; - if Nkind (Parent (Base_Type (Root_Typ))) = - N_Private_Type_Declaration - then - Error_Msg_NE - ("type of aggregate has private ancestor&!", - N, Root_Typ); - Error_Msg_N ("must use extension aggregate!", N); - return; + 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 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); @@ -3020,7 +3752,7 @@ package body Sem_Aggr is end if; end if; - Parent_Typ := Base_Type (Typ); + Parent_Typ := Base_Type (Typ); while Parent_Typ /= Root_Typ loop Prepend_Elmt (Parent_Typ, To => Parent_Typ_List); Parent_Typ := Etype (Parent_Typ); @@ -3043,14 +3775,34 @@ package body Sem_Aggr is 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 + -- 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)), @@ -3066,12 +3818,21 @@ package body Sem_Aggr is if Null_Present (Record_Def) then null; - else + + 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; @@ -3096,7 +3857,7 @@ package body Sem_Aggr is -- Ada 2005 (AI-231) - if Ada_Version >= Ada_05 + if Ada_Version >= Ada_2005 and then Known_Null (Positional_Expr) then Check_Can_Never_Be_Null (Component, Positional_Expr); @@ -3135,7 +3896,12 @@ package body Sem_Aggr is begin -- If there is a default expression for the aggregate, copy - -- it into a new association. + -- 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 @@ -3144,9 +3910,9 @@ package body Sem_Aggr is -- 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. + -- 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 @@ -3154,12 +3920,15 @@ package body Sem_Aggr is and then Present (Expression (Parent (Component))) then Expr := - New_Copy_Tree (Expression (Parent (Component)), - New_Sloc => Sloc (N)); + New_Copy_Tree + (Expression (Parent (Component)), + New_Scope => Current_Scope, + New_Sloc => Sloc (N)); Add_Association - (Component => Component, - Expr => Expr); + (Component => Component, + Expr => Expr, + Assoc_List => New_Assoc_List); Set_Has_Self_Reference (N); -- A box-defaulted access component gets the value null. Also @@ -3174,8 +3943,9 @@ package body Sem_Aggr is Expr := Make_Null (Sloc (N)); Set_Etype (Expr, Ctyp); Add_Association - (Component => Component, - Expr => Expr); + (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 @@ -3197,7 +3967,9 @@ package body Sem_Aggr is begin Analyze_And_Resolve (Convert_Null, Ctyp); Add_Association - (Component => Component, Expr => Convert_Null); + (Component => Component, + Expr => Convert_Null, + Assoc_List => New_Assoc_List); end; end if; @@ -3206,103 +3978,284 @@ package body Sem_Aggr is 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; - declare - Loc : constant Source_Ptr := Sloc (N); - Assoc : Node_Id; - Discr : Entity_Id; - Discr_Elmt : Elmt_Id; - Discr_Val : Node_Id; - Expr : Node_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; - begin - Expr := Make_Aggregate (Loc, New_List, New_List); + 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. - Discr_Elmt := - First_Elmt (Discriminant_Constraint (Ctyp)); - while Present (Discr_Elmt) loop - Discr_Val := Node (Discr_Elmt); + 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 - -- The constraint may be given by a discriminant - -- of the enclosing type, in which case we have - -- to retrieve its value, which is part of the - -- current aggregate. + 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 Is_Entity_Name (Discr_Val) + if Nkind (Def_Node) = N_Record_Definition and then - Ekind (Entity (Discr_Val)) = E_Discriminant + Present (Component_List (Def_Node)) + and then + Present + (Variant_Part (Component_List (Def_Node))) then - Discr := Entity (Discr_Val); - - Assoc := First (New_Assoc_List); - while Present (Assoc) loop - if Present - (Entity (First (Choices (Assoc)))) - and then - Entity (First (Choices (Assoc))) = Discr + 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 - Discr_Val := Expression (Assoc); - exit; + Process_Component (Node (Comp_Elmt)); end if; - Next (Assoc); + + Next_Elmt (Comp_Elmt); end loop; - end if; - Append - (New_Copy_Tree (Discr_Val), Expressions (Expr)); + -- No variant part, iterate over all components - -- If the discriminant constraint is a current - -- instance, mark the current aggregate so that - -- the self-reference can be expanded later. + else + Comp := First_Component (Etype (Aggr)); + while Present (Comp) loop + Process_Component (Comp); + Next_Component (Comp); + end loop; + end if; - 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); + 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; - Next_Elmt (Discr_Elmt); - end loop; + -- Start of processing for Capture_Discriminants + + begin + Expr := Make_Aggregate (Loc, New_List, New_List); + Set_Etype (Expr, Ctyp); - declare - Comp : Entity_Id; + -- If the enclosing type has discriminants, they have + -- been collected in the aggregate earlier, and they + -- may appear as constraints of subcomponents. - begin - -- Look for a component that is not a discriminant - -- before creating an others box association. - - Comp := First_Component (Ctyp); - while Present (Comp) loop - if Ekind (Comp) = E_Component then - Append - (Make_Component_Association (Loc, - Choices => - New_List (Make_Others_Choice (Loc)), - Expression => Empty, - Box_Present => True), - Component_Associations (Expr)); - exit; - end if; + -- Similarly if this component has discriminants, they + -- might in turn be propagated to their components. - Next_Component (Comp); - end loop; - end; + 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); - end; + (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; @@ -3372,7 +4325,15 @@ package body Sem_Aggr is New_Assoc := First (New_Assoc_List); while Present (New_Assoc) loop Component := First (Choices (New_Assoc)); - exit when Chars (Selectr) = Chars (Component); + + 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; @@ -3419,7 +4380,6 @@ package body Sem_Aggr is elsif Chars (Selectr) /= Name_uTag and then Chars (Selectr) /= Name_uParent - and then Chars (Selectr) /= Name_uController then if not Has_Discriminants (Typ) then Error_Msg_Node_2 := Typ; @@ -3436,8 +4396,23 @@ package body Sem_Aggr is 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 not Box_Present (Parent (Selectr)) 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); @@ -3474,7 +4449,7 @@ package body Sem_Aggr is begin pragma Assert - (Ada_Version >= Ada_05 + (Ada_Version >= Ada_2005 and then Present (Expr) and then Known_Null (Expr));