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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C A S E -- -- -- -- B o d y -- -- -- -- Copyright (C) 1996-2010, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Einfo; use Einfo; with Errout; use Errout; with Namet; use Namet; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Util; use Sem_Util; with Sem_Type; use Sem_Type; with Snames; use Snames; with Stand; use Stand; with Sinfo; use Sinfo; with Tbuild; use Tbuild; with Uintp; use Uintp; with Ada.Unchecked_Deallocation; with GNAT.Heap_Sort_G; package body Sem_Case is type Choice_Bounds is record Lo : Node_Id; Hi : Node_Id; Node : Node_Id; end record; -- Represent one choice bounds entry with Lo and Hi values, Node points -- to the choice node itself. type Choice_Table_Type is array (Nat range <>) of Choice_Bounds; -- Table type used to sort the choices present in a case statement, array -- aggregate or record variant. The actual entries are stored in 1 .. Last, -- but we have a 0 entry for convenience in sorting. ----------------------- -- Local Subprograms -- ----------------------- procedure Check_Choices (Choice_Table : in out Choice_Table_Type; Bounds_Type : Entity_Id; Subtyp : Entity_Id; Others_Present : Boolean; Case_Node : Node_Id); -- This is the procedure which verifies that a set of case alternatives -- or record variant choices has no duplicates, and covers the range -- specified by Bounds_Type. Choice_Table contains the discrete choices -- to check. These must start at position 1. -- -- Furthermore Choice_Table (0) must exist. This element is used by -- the sorting algorithm as a temporary. Others_Present is a flag -- indicating whether or not an Others choice is present. Finally -- Msg_Sloc gives the source location of the construct containing the -- choices in the Choice_Table. -- -- Bounds_Type is the type whose range must be covered by the alternatives -- -- Subtyp is the subtype of the expression. If its bounds are non-static -- the alternatives must cover its base type. function Choice_Image (Value : Uint; Ctype : Entity_Id) return Name_Id; -- Given a Pos value of enumeration type Ctype, returns the name -- ID of an appropriate string to be used in error message output. procedure Expand_Others_Choice (Case_Table : Choice_Table_Type; Others_Choice : Node_Id; Choice_Type : Entity_Id); -- The case table is the table generated by a call to Analyze_Choices -- (with just 1 .. Last_Choice entries present). Others_Choice is a -- pointer to the N_Others_Choice node (this routine is only called if -- an others choice is present), and Choice_Type is the discrete type -- of the bounds. The effect of this call is to analyze the cases and -- determine the set of values covered by others. This choice list is -- set in the Others_Discrete_Choices field of the N_Others_Choice node. ------------------- -- Check_Choices -- ------------------- procedure Check_Choices (Choice_Table : in out Choice_Table_Type; Bounds_Type : Entity_Id; Subtyp : Entity_Id; Others_Present : Boolean; Case_Node : Node_Id) is procedure Explain_Non_Static_Bound; -- Called when we find a non-static bound, requiring the base type to -- be covered. Provides where possible a helpful explanation of why the -- bounds are non-static, since this is not always obvious. function Lt_Choice (C1, C2 : Natural) return Boolean; -- Comparison routine for comparing Choice_Table entries. Use the lower -- bound of each Choice as the key. procedure Move_Choice (From : Natural; To : Natural); -- Move routine for sorting the Choice_Table package Sorting is new GNAT.Heap_Sort_G (Move_Choice, Lt_Choice); procedure Issue_Msg (Value1 : Node_Id; Value2 : Node_Id); procedure Issue_Msg (Value1 : Node_Id; Value2 : Uint); procedure Issue_Msg (Value1 : Uint; Value2 : Node_Id); procedure Issue_Msg (Value1 : Uint; Value2 : Uint); -- Issue an error message indicating that there are missing choices, -- followed by the image of the missing choices themselves which lie -- between Value1 and Value2 inclusive. --------------- -- Issue_Msg -- --------------- procedure Issue_Msg (Value1 : Node_Id; Value2 : Node_Id) is begin Issue_Msg (Expr_Value (Value1), Expr_Value (Value2)); end Issue_Msg; procedure Issue_Msg (Value1 : Node_Id; Value2 : Uint) is begin Issue_Msg (Expr_Value (Value1), Value2); end Issue_Msg; procedure Issue_Msg (Value1 : Uint; Value2 : Node_Id) is begin Issue_Msg (Value1, Expr_Value (Value2)); end Issue_Msg; procedure Issue_Msg (Value1 : Uint; Value2 : Uint) is Msg_Sloc : constant Source_Ptr := Sloc (Case_Node); begin -- In some situations, we call this with a null range, and -- obviously we don't want to complain in this case! if Value1 > Value2 then return; end if; -- Case of only one value that is missing if Value1 = Value2 then if Is_Integer_Type (Bounds_Type) then Error_Msg_Uint_1 := Value1; Error_Msg ("missing case value: ^!", Msg_Sloc); else Error_Msg_Name_1 := Choice_Image (Value1, Bounds_Type); Error_Msg ("missing case value: %!", Msg_Sloc); end if; -- More than one choice value, so print range of values else if Is_Integer_Type (Bounds_Type) then Error_Msg_Uint_1 := Value1; Error_Msg_Uint_2 := Value2; Error_Msg ("missing case values: ^ .. ^!", Msg_Sloc); else Error_Msg_Name_1 := Choice_Image (Value1, Bounds_Type); Error_Msg_Name_2 := Choice_Image (Value2, Bounds_Type); Error_Msg ("missing case values: % .. %!", Msg_Sloc); end if; end if; end Issue_Msg; --------------- -- Lt_Choice -- --------------- function Lt_Choice (C1, C2 : Natural) return Boolean is begin return Expr_Value (Choice_Table (Nat (C1)).Lo) < Expr_Value (Choice_Table (Nat (C2)).Lo); end Lt_Choice; ----------------- -- Move_Choice -- ----------------- procedure Move_Choice (From : Natural; To : Natural) is begin Choice_Table (Nat (To)) := Choice_Table (Nat (From)); end Move_Choice; ------------------------------ -- Explain_Non_Static_Bound -- ------------------------------ procedure Explain_Non_Static_Bound is Expr : Node_Id; begin if Nkind (Case_Node) = N_Variant_Part then Expr := Name (Case_Node); else Expr := Expression (Case_Node); end if; if Bounds_Type /= Subtyp then -- If the case is a variant part, the expression is given by -- the discriminant itself, and the bounds are the culprits. if Nkind (Case_Node) = N_Variant_Part then Error_Msg_NE ("bounds of & are not static," & " alternatives must cover base type", Expr, Expr); -- If this is a case statement, the expression may be -- non-static or else the subtype may be at fault. elsif Is_Entity_Name (Expr) then Error_Msg_NE ("bounds of & are not static," & " alternatives must cover base type", Expr, Expr); else Error_Msg_N ("subtype of expression is not static," & " alternatives must cover base type!", Expr); end if; -- Otherwise the expression is not static, even if the bounds of the -- type are, or else there are missing alternatives. If both, the -- additional information may be redundant but harmless. elsif not Is_Entity_Name (Expr) then Error_Msg_N ("subtype of expression is not static, " & "alternatives must cover base type!", Expr); end if; end Explain_Non_Static_Bound; -- Variables local to Check_Choices Choice : Node_Id; Bounds_Lo : constant Node_Id := Type_Low_Bound (Bounds_Type); Bounds_Hi : constant Node_Id := Type_High_Bound (Bounds_Type); Prev_Choice : Node_Id; Hi : Uint; Lo : Uint; Prev_Hi : Uint; -- Start of processing for Check_Choices begin -- Choice_Table must start at 0 which is an unused location used -- by the sorting algorithm. However the first valid position for -- a discrete choice is 1. pragma Assert (Choice_Table'First = 0); if Choice_Table'Last = 0 then if not Others_Present then Issue_Msg (Bounds_Lo, Bounds_Hi); end if; return; end if; Sorting.Sort (Positive (Choice_Table'Last)); Lo := Expr_Value (Choice_Table (1).Lo); Hi := Expr_Value (Choice_Table (1).Hi); Prev_Hi := Hi; if not Others_Present and then Expr_Value (Bounds_Lo) < Lo then Issue_Msg (Bounds_Lo, Lo - 1); -- If values are missing outside of the subtype, add explanation. -- No additional message if only one value is missing. if Expr_Value (Bounds_Lo) < Lo - 1 then Explain_Non_Static_Bound; end if; end if; for J in 2 .. Choice_Table'Last loop Lo := Expr_Value (Choice_Table (J).Lo); Hi := Expr_Value (Choice_Table (J).Hi); if Lo <= Prev_Hi then Choice := Choice_Table (J).Node; -- Find first previous choice that overlaps for K in 1 .. J - 1 loop if Lo <= Expr_Value (Choice_Table (K).Hi) then Prev_Choice := Choice_Table (K).Node; exit; end if; end loop; if Sloc (Prev_Choice) <= Sloc (Choice) then Error_Msg_Sloc := Sloc (Prev_Choice); Error_Msg_N ("duplication of choice value#", Choice); else Error_Msg_Sloc := Sloc (Choice); Error_Msg_N ("duplication of choice value#", Prev_Choice); end if; elsif not Others_Present and then Lo /= Prev_Hi + 1 then Issue_Msg (Prev_Hi + 1, Lo - 1); end if; if Hi > Prev_Hi then Prev_Hi := Hi; end if; end loop; if not Others_Present and then Expr_Value (Bounds_Hi) > Hi then Issue_Msg (Hi + 1, Bounds_Hi); if Expr_Value (Bounds_Hi) > Hi + 1 then Explain_Non_Static_Bound; end if; end if; end Check_Choices; ------------------ -- Choice_Image -- ------------------ function Choice_Image (Value : Uint; Ctype : Entity_Id) return Name_Id is Rtp : constant Entity_Id := Root_Type (Ctype); Lit : Entity_Id; C : Int; begin -- For character, or wide [wide] character. If 7-bit ASCII graphic -- range, then build and return appropriate character literal name if Is_Standard_Character_Type (Ctype) then C := UI_To_Int (Value); if C in 16#20# .. 16#7E# then Set_Character_Literal_Name (Char_Code (UI_To_Int (Value))); return Name_Find; end if; -- For user defined enumeration type, find enum/char literal else Lit := First_Literal (Rtp); for J in 1 .. UI_To_Int (Value) loop Next_Literal (Lit); end loop; -- If enumeration literal, just return its value if Nkind (Lit) = N_Defining_Identifier then return Chars (Lit); -- For character literal, get the name and use it if it is -- for a 7-bit ASCII graphic character in 16#20#..16#7E#. else Get_Decoded_Name_String (Chars (Lit)); if Name_Len = 3 and then Name_Buffer (2) in Character'Val (16#20#) .. Character'Val (16#7E#) then return Chars (Lit); end if; end if; end if; -- If we fall through, we have a character literal which is not in -- the 7-bit ASCII graphic set. For such cases, we construct the -- name "type'val(nnn)" where type is the choice type, and nnn is -- the pos value passed as an argument to Choice_Image. Get_Name_String (Chars (First_Subtype (Ctype))); Add_Str_To_Name_Buffer ("'val("); UI_Image (Value); Add_Str_To_Name_Buffer (UI_Image_Buffer (1 .. UI_Image_Length)); Add_Char_To_Name_Buffer (')'); return Name_Find; end Choice_Image; -------------------------- -- Expand_Others_Choice -- -------------------------- procedure Expand_Others_Choice (Case_Table : Choice_Table_Type; Others_Choice : Node_Id; Choice_Type : Entity_Id) is Loc : constant Source_Ptr := Sloc (Others_Choice); Choice_List : constant List_Id := New_List; Choice : Node_Id; Exp_Lo : Node_Id; Exp_Hi : Node_Id; Hi : Uint; Lo : Uint; Previous_Hi : Uint; function Build_Choice (Value1, Value2 : Uint) return Node_Id; -- Builds a node representing the missing choices given by the -- Value1 and Value2. A N_Range node is built if there is more than -- one literal value missing. Otherwise a single N_Integer_Literal, -- N_Identifier or N_Character_Literal is built depending on what -- Choice_Type is. function Lit_Of (Value : Uint) return Node_Id; -- Returns the Node_Id for the enumeration literal corresponding to the -- position given by Value within the enumeration type Choice_Type. ------------------ -- Build_Choice -- ------------------ function Build_Choice (Value1, Value2 : Uint) return Node_Id is Lit_Node : Node_Id; Lo, Hi : Node_Id; begin -- If there is only one choice value missing between Value1 and -- Value2, build an integer or enumeration literal to represent it. if (Value2 - Value1) = 0 then if Is_Integer_Type (Choice_Type) then Lit_Node := Make_Integer_Literal (Loc, Value1); Set_Etype (Lit_Node, Choice_Type); else Lit_Node := Lit_Of (Value1); end if; -- Otherwise is more that one choice value that is missing between -- Value1 and Value2, therefore build a N_Range node of either -- integer or enumeration literals. else if Is_Integer_Type (Choice_Type) then Lo := Make_Integer_Literal (Loc, Value1); Set_Etype (Lo, Choice_Type); Hi := Make_Integer_Literal (Loc, Value2); Set_Etype (Hi, Choice_Type); Lit_Node := Make_Range (Loc, Low_Bound => Lo, High_Bound => Hi); else Lit_Node := Make_Range (Loc, Low_Bound => Lit_Of (Value1), High_Bound => Lit_Of (Value2)); end if; end if; return Lit_Node; end Build_Choice; ------------ -- Lit_Of -- ------------ function Lit_Of (Value : Uint) return Node_Id is Lit : Entity_Id; begin -- In the case where the literal is of type Character, there needs -- to be some special handling since there is no explicit chain -- of literals to search. Instead, a N_Character_Literal node -- is created with the appropriate Char_Code and Chars fields. if Is_Standard_Character_Type (Choice_Type) then Set_Character_Literal_Name (Char_Code (UI_To_Int (Value))); Lit := New_Node (N_Character_Literal, Loc); Set_Chars (Lit, Name_Find); Set_Char_Literal_Value (Lit, Value); Set_Etype (Lit, Choice_Type); Set_Is_Static_Expression (Lit, True); return Lit; -- Otherwise, iterate through the literals list of Choice_Type -- "Value" number of times until the desired literal is reached -- and then return an occurrence of it. else Lit := First_Literal (Choice_Type); for J in 1 .. UI_To_Int (Value) loop Next_Literal (Lit); end loop; return New_Occurrence_Of (Lit, Loc); end if; end Lit_Of; -- Start of processing for Expand_Others_Choice begin if Case_Table'Last = 0 then -- Special case: only an others case is present. -- The others case covers the full range of the type. if Is_Static_Subtype (Choice_Type) then Choice := New_Occurrence_Of (Choice_Type, Loc); else Choice := New_Occurrence_Of (Base_Type (Choice_Type), Loc); end if; Set_Others_Discrete_Choices (Others_Choice, New_List (Choice)); return; end if; -- Establish the bound values for the choice depending upon whether -- the type of the case statement is static or not. if Is_OK_Static_Subtype (Choice_Type) then Exp_Lo := Type_Low_Bound (Choice_Type); Exp_Hi := Type_High_Bound (Choice_Type); else Exp_Lo := Type_Low_Bound (Base_Type (Choice_Type)); Exp_Hi := Type_High_Bound (Base_Type (Choice_Type)); end if; Lo := Expr_Value (Case_Table (1).Lo); Hi := Expr_Value (Case_Table (1).Hi); Previous_Hi := Expr_Value (Case_Table (1).Hi); -- Build the node for any missing choices that are smaller than any -- explicit choices given in the case. if Expr_Value (Exp_Lo) < Lo then Append (Build_Choice (Expr_Value (Exp_Lo), Lo - 1), Choice_List); end if; -- Build the nodes representing any missing choices that lie between -- the explicit ones given in the case. for J in 2 .. Case_Table'Last loop Lo := Expr_Value (Case_Table (J).Lo); Hi := Expr_Value (Case_Table (J).Hi); if Lo /= (Previous_Hi + 1) then Append_To (Choice_List, Build_Choice (Previous_Hi + 1, Lo - 1)); end if; Previous_Hi := Hi; end loop; -- Build the node for any missing choices that are greater than any -- explicit choices given in the case. if Expr_Value (Exp_Hi) > Hi then Append (Build_Choice (Hi + 1, Expr_Value (Exp_Hi)), Choice_List); end if; Set_Others_Discrete_Choices (Others_Choice, Choice_List); -- Warn on null others list if warning option set if Warn_On_Redundant_Constructs and then Comes_From_Source (Others_Choice) and then Is_Empty_List (Choice_List) then Error_Msg_N ("?OTHERS choice is redundant", Others_Choice); Error_Msg_N ("\previous choices cover all values", Others_Choice); end if; end Expand_Others_Choice; ----------- -- No_OP -- ----------- procedure No_OP (C : Node_Id) is pragma Warnings (Off, C); begin null; end No_OP; -------------------------------- -- Generic_Choices_Processing -- -------------------------------- package body Generic_Choices_Processing is -- The following type is used to gather the entries for the choice -- table, so that we can then allocate the right length. type Link; type Link_Ptr is access all Link; type Link is record Val : Choice_Bounds; Nxt : Link_Ptr; end record; procedure Free is new Ada.Unchecked_Deallocation (Link, Link_Ptr); --------------------- -- Analyze_Choices -- --------------------- procedure Analyze_Choices (N : Node_Id; Subtyp : Entity_Id; Raises_CE : out Boolean; Others_Present : out Boolean) is E : Entity_Id; Enode : Node_Id; -- This is where we post error messages for bounds out of range Choice_List : Link_Ptr := null; -- Gather list of choices Num_Choices : Nat := 0; -- Number of entries in Choice_List Choice_Type : constant Entity_Id := Base_Type (Subtyp); -- The actual type against which the discrete choices are resolved. -- Note that this type is always the base type not the subtype of the -- ruling expression, index or discriminant. Bounds_Type : Entity_Id; -- The type from which are derived the bounds of the values covered -- by the discrete choices (see 3.8.1 (4)). If a discrete choice -- specifies a value outside of these bounds we have an error. Bounds_Lo : Uint; Bounds_Hi : Uint; -- The actual bounds of the above type Expected_Type : Entity_Id; -- The expected type of each choice. Equal to Choice_Type, except if -- the expression is universal, in which case the choices can be of -- any integer type. Alt : Node_Id; -- A case statement alternative or a variant in a record type -- declaration. Choice : Node_Id; Kind : Node_Kind; -- The node kind of the current Choice Delete_Choice : Boolean; -- Set to True to delete the current choice Others_Choice : Node_Id := Empty; -- Remember others choice if it is present (empty otherwise) procedure Check (Choice : Node_Id; Lo, Hi : Node_Id); -- Checks the validity of the bounds of a choice. When the bounds -- are static and no error occurred the bounds are collected for -- later entry into the choices table so that they can be sorted -- later on. ----------- -- Check -- ----------- procedure Check (Choice : Node_Id; Lo, Hi : Node_Id) is Lo_Val : Uint; Hi_Val : Uint; begin -- First check if an error was already detected on either bounds if Etype (Lo) = Any_Type or else Etype (Hi) = Any_Type then return; -- Do not insert non static choices in the table to be sorted elsif not Is_Static_Expression (Lo) or else not Is_Static_Expression (Hi) then Process_Non_Static_Choice (Choice); return; -- Ignore range which raise constraint error elsif Raises_Constraint_Error (Lo) or else Raises_Constraint_Error (Hi) then Raises_CE := True; return; -- Otherwise we have an OK static choice else Lo_Val := Expr_Value (Lo); Hi_Val := Expr_Value (Hi); -- Do not insert null ranges in the choices table if Lo_Val > Hi_Val then Process_Empty_Choice (Choice); return; end if; end if; -- Check for low bound out of range if Lo_Val < Bounds_Lo then -- If the choice is an entity name, then it is a type, and we -- want to post the message on the reference to this entity. -- Otherwise post it on the lower bound of the range. if Is_Entity_Name (Choice) then Enode := Choice; else Enode := Lo; end if; -- Specialize message for integer/enum type if Is_Integer_Type (Bounds_Type) then Error_Msg_Uint_1 := Bounds_Lo; Error_Msg_N ("minimum allowed choice value is^", Enode); else Error_Msg_Name_1 := Choice_Image (Bounds_Lo, Bounds_Type); Error_Msg_N ("minimum allowed choice value is%", Enode); end if; end if; -- Check for high bound out of range if Hi_Val > Bounds_Hi then -- If the choice is an entity name, then it is a type, and we -- want to post the message on the reference to this entity. -- Otherwise post it on the upper bound of the range. if Is_Entity_Name (Choice) then Enode := Choice; else Enode := Hi; end if; -- Specialize message for integer/enum type if Is_Integer_Type (Bounds_Type) then Error_Msg_Uint_1 := Bounds_Hi; Error_Msg_N ("maximum allowed choice value is^", Enode); else Error_Msg_Name_1 := Choice_Image (Bounds_Hi, Bounds_Type); Error_Msg_N ("maximum allowed choice value is%", Enode); end if; end if; -- Collect bounds in the list -- Note: we still store the bounds, even if they are out of range, -- since this may prevent unnecessary cascaded errors for values -- that are covered by such an excessive range. Choice_List := new Link'(Val => (Lo, Hi, Choice), Nxt => Choice_List); Num_Choices := Num_Choices + 1; end Check; -- Start of processing for Analyze_Choices begin Raises_CE := False; Others_Present := False; -- If Subtyp is not a static subtype Ada 95 requires then we use the -- bounds of its base type to determine the values covered by the -- discrete choices. if Is_OK_Static_Subtype (Subtyp) then Bounds_Type := Subtyp; else Bounds_Type := Choice_Type; end if; -- Obtain static bounds of type, unless this is a generic formal -- discrete type for which all choices will be non-static. if not Is_Generic_Type (Root_Type (Bounds_Type)) or else Ekind (Bounds_Type) /= E_Enumeration_Type then Bounds_Lo := Expr_Value (Type_Low_Bound (Bounds_Type)); Bounds_Hi := Expr_Value (Type_High_Bound (Bounds_Type)); end if; if Choice_Type = Universal_Integer then Expected_Type := Any_Integer; else Expected_Type := Choice_Type; end if; -- Now loop through the case alternatives or record variants Alt := First (Get_Alternatives (N)); while Present (Alt) loop -- If pragma, just analyze it if Nkind (Alt) = N_Pragma then Analyze (Alt); -- Otherwise check each choice against its base type else Choice := First (Get_Choices (Alt)); while Present (Choice) loop Delete_Choice := False; Analyze (Choice); Kind := Nkind (Choice); -- Choice is a Range if Kind = N_Range or else (Kind = N_Attribute_Reference and then Attribute_Name (Choice) = Name_Range) then Resolve (Choice, Expected_Type); Check (Choice, Low_Bound (Choice), High_Bound (Choice)); -- Choice is a subtype name elsif Is_Entity_Name (Choice) and then Is_Type (Entity (Choice)) then if not Covers (Expected_Type, Etype (Choice)) then Wrong_Type (Choice, Choice_Type); else E := Entity (Choice); -- Case of predicated subtype if Has_Predicates (E) then -- Use of non-static predicate is an error if not Is_Discrete_Type (E) or else No (Static_Predicate (E)) then Bad_Predicated_Subtype_Use ("cannot use subtype& with non-static " & "predicate as case alternative", Choice, E); -- Static predicate case else declare Copy : constant List_Id := Empty_List; P : Node_Id; C : Node_Id; begin -- Loop through entries in predicate list, -- converting to choices. Note that if the -- list is empty, corresponding to a False -- predicate, then no choices are inserted. P := First (Static_Predicate (E)); while Present (P) loop C := New_Copy (P); Set_Sloc (C, Sloc (Choice)); Append_To (Copy, C); Next (P); end loop; Insert_List_After (Choice, Copy); Delete_Choice := True; end; end if; -- Not predicated subtype case elsif not Is_Static_Subtype (E) then Process_Non_Static_Choice (Choice); else Check (Choice, Type_Low_Bound (E), Type_High_Bound (E)); end if; end if; -- Choice is a subtype indication elsif Kind = N_Subtype_Indication then Resolve_Discrete_Subtype_Indication (Choice, Expected_Type); -- Here for other than predicated subtype case if Etype (Choice) /= Any_Type then declare C : constant Node_Id := Constraint (Choice); R : constant Node_Id := Range_Expression (C); L : constant Node_Id := Low_Bound (R); H : constant Node_Id := High_Bound (R); begin E := Entity (Subtype_Mark (Choice)); if not Is_Static_Subtype (E) then Process_Non_Static_Choice (Choice); else if Is_OK_Static_Expression (L) and then Is_OK_Static_Expression (H) then if Expr_Value (L) > Expr_Value (H) then Process_Empty_Choice (Choice); else if Is_Out_Of_Range (L, E) then Apply_Compile_Time_Constraint_Error (L, "static value out of range", CE_Range_Check_Failed); end if; if Is_Out_Of_Range (H, E) then Apply_Compile_Time_Constraint_Error (H, "static value out of range", CE_Range_Check_Failed); end if; end if; end if; Check (Choice, L, H); end if; end; end if; -- The others choice is only allowed for the last -- alternative and as its only choice. elsif Kind = N_Others_Choice then if not (Choice = First (Get_Choices (Alt)) and then Choice = Last (Get_Choices (Alt)) and then Alt = Last (Get_Alternatives (N))) then Error_Msg_N ("the choice OTHERS must appear alone and last", Choice); return; end if; Others_Present := True; Others_Choice := Choice; -- Only other possibility is an expression else Resolve (Choice, Expected_Type); Check (Choice, Choice, Choice); end if; -- Move to next choice, deleting the current one if the -- flag requesting this deletion is set True. declare C : constant Node_Id := Choice; begin Next (Choice); if Delete_Choice then Remove (C); end if; end; end loop; Process_Associated_Node (Alt); end if; Next (Alt); end loop; -- Now we can create the Choice_Table, since we know how long -- it needs to be so we can allocate exactly the right length. declare Choice_Table : Choice_Table_Type (0 .. Num_Choices); begin -- Now copy the items we collected in the linked list into this -- newly allocated table (leave entry 0 unused for sorting). declare T : Link_Ptr; begin for J in 1 .. Num_Choices loop T := Choice_List; Choice_List := T.Nxt; Choice_Table (J) := T.Val; Free (T); end loop; end; Check_Choices (Choice_Table, Bounds_Type, Subtyp, Others_Present or else (Choice_Type = Universal_Integer), N); -- If no others choice we are all done, otherwise we have one more -- step, which is to set the Others_Discrete_Choices field of the -- others choice (to contain all otherwise unspecified choices). -- Skip this if CE is known to be raised. if Others_Present and not Raises_CE then Expand_Others_Choice (Case_Table => Choice_Table, Others_Choice => Others_Choice, Choice_Type => Bounds_Type); end if; end; end Analyze_Choices; end Generic_Choices_Processing; end Sem_Case;
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