+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S E M _ C H 6 --
--- --
--- B o d y --
--- --
--- $Revision: 1.2.12.1 $
--- --
--- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
--- --
--- GNAT is free software; you can redistribute it and/or modify it under --
--- terms of the GNU General Public License as published by the Free Soft- --
--- ware Foundation; either version 2, or (at your option) any later ver- --
--- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
--- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
--- --
--- GNAT was originally developed by the GNAT team at New York University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-with Atree; use Atree;
-with Checks; use Checks;
-with Debug; use Debug;
-with Einfo; use Einfo;
-with Elists; use Elists;
-with Errout; use Errout;
-with Expander; use Expander;
-with Exp_Ch7; use Exp_Ch7;
-with Fname; use Fname;
-with Freeze; use Freeze;
-with Lib.Xref; use Lib.Xref;
-with Namet; use Namet;
-with Lib; use Lib;
-with Nlists; use Nlists;
-with Nmake; use Nmake;
-with Opt; use Opt;
-with Output; use Output;
-with Rtsfind; use Rtsfind;
-with Sem; use Sem;
-with Sem_Cat; use Sem_Cat;
-with Sem_Ch3; use Sem_Ch3;
-with Sem_Ch4; use Sem_Ch4;
-with Sem_Ch5; use Sem_Ch5;
-with Sem_Ch8; use Sem_Ch8;
-with Sem_Ch12; use Sem_Ch12;
-with Sem_Disp; use Sem_Disp;
-with Sem_Dist; use Sem_Dist;
-with Sem_Elim; use Sem_Elim;
-with Sem_Eval; use Sem_Eval;
-with Sem_Mech; use Sem_Mech;
-with Sem_Prag; use Sem_Prag;
-with Sem_Res; use Sem_Res;
-with Sem_Util; use Sem_Util;
-with Sem_Type; use Sem_Type;
-with Sem_Warn; use Sem_Warn;
-with Sinput; use Sinput;
-with Stand; use Stand;
-with Sinfo; use Sinfo;
-with Sinfo.CN; use Sinfo.CN;
-with Snames; use Snames;
-with Stringt; use Stringt;
-with Style;
-with Stylesw; use Stylesw;
-with Tbuild; use Tbuild;
-with Uintp; use Uintp;
-with Urealp; use Urealp;
-with Validsw; use Validsw;
-
-package body Sem_Ch6 is
-
- -----------------------
- -- Local Subprograms --
- -----------------------
-
- procedure Analyze_Generic_Subprogram_Body (N : Node_Id; Gen_Id : Entity_Id);
- -- Analyze a generic subprogram body
-
- function Build_Body_To_Inline
- (N : Node_Id;
- Subp : Entity_Id;
- Orig_Body : Node_Id)
- return Boolean;
- -- If a subprogram has pragma Inline and inlining is active, use generic
- -- machinery to build an unexpanded body for the subprogram. This body is
- -- subsequenty used for inline expansions at call sites. If subprogram can
- -- be inlined (depending on size and nature of local declarations) this
- -- function returns true. Otherwise subprogram body is treated normally.
-
- type Conformance_Type is
- (Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
-
- procedure Check_Conformance
- (New_Id : Entity_Id;
- Old_Id : Entity_Id;
- Ctype : Conformance_Type;
- Errmsg : Boolean;
- Conforms : out Boolean;
- Err_Loc : Node_Id := Empty;
- Get_Inst : Boolean := False);
- -- Given two entities, this procedure checks that the profiles associated
- -- with these entities meet the conformance criterion given by the third
- -- parameter. If they conform, Conforms is set True and control returns
- -- to the caller. If they do not conform, Conforms is set to False, and
- -- in addition, if Errmsg is True on the call, proper messages are output
- -- to complain about the conformance failure. If Err_Loc is non_Empty
- -- the error messages are placed on Err_Loc, if Err_Loc is empty, then
- -- error messages are placed on the appropriate part of the construct
- -- denoted by New_Id. If Get_Inst is true, then this is a mode conformance
- -- against a formal access-to-subprogram type so Get_Instance_Of must
- -- be called.
-
- procedure Check_Subprogram_Order (N : Node_Id);
- -- N is the N_Subprogram_Body node for a subprogram. This routine applies
- -- the alpha ordering rule for N if this ordering requirement applicable.
-
- function Is_Non_Overriding_Operation
- (Prev_E : Entity_Id;
- New_E : Entity_Id)
- return Boolean;
- -- Enforce the rule given in 12.3(18): a private operation in an instance
- -- overrides an inherited operation only if the corresponding operation
- -- was overriding in the generic. This can happen for primitive operations
- -- of types derived (in the generic unit) from formal private or formal
- -- derived types.
-
- procedure Check_Returns
- (HSS : Node_Id;
- Mode : Character;
- Err : out Boolean);
- -- Called to check for missing return statements in a function body,
- -- or for returns present in a procedure body which has No_Return set.
- -- L is the handled statement sequence for the subprogram body. This
- -- procedure checks all flow paths to make sure they either have a
- -- return (Mode = 'F') or do not have a return (Mode = 'P'). The flag
- -- Err is set if there are any control paths not explicitly terminated
- -- by a return in the function case, and is True otherwise.
-
- function Conforming_Types
- (T1 : Entity_Id;
- T2 : Entity_Id;
- Ctype : Conformance_Type;
- Get_Inst : Boolean := False)
- return Boolean;
- -- Check that two formal parameter types conform, checking both
- -- for equality of base types, and where required statically
- -- matching subtypes, depending on the setting of Ctype.
-
- procedure Enter_Overloaded_Entity (S : Entity_Id);
- -- This procedure makes S, a new overloaded entity, into the first
- -- visible entity with that name.
-
- procedure Install_Entity (E : Entity_Id);
- -- Make single entity visible. Used for generic formals as well.
-
- procedure Install_Formals (Id : Entity_Id);
- -- On entry to a subprogram body, make the formals visible. Note
- -- that simply placing the subprogram on the scope stack is not
- -- sufficient: the formals must become the current entities for
- -- their names.
-
- procedure Make_Inequality_Operator (S : Entity_Id);
- -- Create the declaration for an inequality operator that is implicitly
- -- created by a user-defined equality operator that yields a boolean.
-
- procedure May_Need_Actuals (Fun : Entity_Id);
- -- Flag functions that can be called without parameters, i.e. those that
- -- have no parameters, or those for which defaults exist for all parameters
-
- procedure Set_Formal_Validity (Formal_Id : Entity_Id);
- -- Formal_Id is an formal parameter entity. This procedure deals with
- -- setting the proper validity status for this entity, which depends
- -- on the kind of parameter and the validity checking mode.
-
- ---------------------------------------------
- -- Analyze_Abstract_Subprogram_Declaration --
- ---------------------------------------------
-
- procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id) is
- Designator : constant Entity_Id := Analyze_Spec (Specification (N));
- Scop : constant Entity_Id := Current_Scope;
-
- begin
- Generate_Definition (Designator);
- Set_Is_Abstract (Designator);
- New_Overloaded_Entity (Designator);
- Check_Delayed_Subprogram (Designator);
-
- Set_Is_Pure (Designator,
- Is_Pure (Scop) and then Is_Library_Level_Entity (Designator));
- Set_Is_Remote_Call_Interface (
- Designator, Is_Remote_Call_Interface (Scop));
- Set_Is_Remote_Types (Designator, Is_Remote_Types (Scop));
-
- if Ekind (Scope (Designator)) = E_Protected_Type then
- Error_Msg_N
- ("abstract subprogram not allowed in protected type", N);
- end if;
- end Analyze_Abstract_Subprogram_Declaration;
-
- ----------------------------
- -- Analyze_Function_Call --
- ----------------------------
-
- procedure Analyze_Function_Call (N : Node_Id) is
- P : constant Node_Id := Name (N);
- L : constant List_Id := Parameter_Associations (N);
- Actual : Node_Id;
-
- begin
- Analyze (P);
-
- -- If error analyzing name, then set Any_Type as result type and return
-
- if Etype (P) = Any_Type then
- Set_Etype (N, Any_Type);
- return;
- end if;
-
- -- Otherwise analyze the parameters
-
- if Present (L) then
- Actual := First (L);
-
- while Present (Actual) loop
- Analyze (Actual);
- Check_Parameterless_Call (Actual);
- Next (Actual);
- end loop;
- end if;
-
- Analyze_Call (N);
-
- end Analyze_Function_Call;
-
- -------------------------------------
- -- Analyze_Generic_Subprogram_Body --
- -------------------------------------
-
- procedure Analyze_Generic_Subprogram_Body
- (N : Node_Id;
- Gen_Id : Entity_Id)
- is
- Gen_Decl : constant Node_Id := Unit_Declaration_Node (Gen_Id);
- Spec : Node_Id;
- Kind : constant Entity_Kind := Ekind (Gen_Id);
- Nam : Entity_Id;
- New_N : Node_Id;
-
- begin
- -- Copy body and disable expansion while analyzing the generic
- -- For a stub, do not copy the stub (which would load the proper body),
- -- this will be done when the proper body is analyzed.
-
- if Nkind (N) /= N_Subprogram_Body_Stub then
- New_N := Copy_Generic_Node (N, Empty, Instantiating => False);
- Rewrite (N, New_N);
- Start_Generic;
- end if;
-
- Spec := Specification (N);
-
- -- Within the body of the generic, the subprogram is callable, and
- -- behaves like the corresponding non-generic unit.
-
- Nam := Defining_Entity (Spec);
-
- if Kind = E_Generic_Procedure
- and then Nkind (Spec) /= N_Procedure_Specification
- then
- Error_Msg_N ("invalid body for generic procedure ", Nam);
- return;
-
- elsif Kind = E_Generic_Function
- and then Nkind (Spec) /= N_Function_Specification
- then
- Error_Msg_N ("invalid body for generic function ", Nam);
- return;
- end if;
-
- Set_Corresponding_Body (Gen_Decl, Nam);
-
- if Has_Completion (Gen_Id)
- and then Nkind (Parent (N)) /= N_Subunit
- then
- Error_Msg_N ("duplicate generic body", N);
- return;
- else
- Set_Has_Completion (Gen_Id);
- end if;
-
- if Nkind (N) = N_Subprogram_Body_Stub then
- Set_Ekind (Defining_Entity (Specification (N)), Kind);
- else
- Set_Corresponding_Spec (N, Gen_Id);
- end if;
-
- if Nkind (Parent (N)) = N_Compilation_Unit then
- Set_Cunit_Entity (Current_Sem_Unit, Defining_Entity (N));
- end if;
-
- -- Make generic parameters immediately visible in the body. They are
- -- needed to process the formals declarations. Then make the formals
- -- visible in a separate step.
-
- New_Scope (Gen_Id);
-
- declare
- E : Entity_Id;
- First_Ent : Entity_Id;
-
- begin
- First_Ent := First_Entity (Gen_Id);
-
- E := First_Ent;
- while Present (E) and then not Is_Formal (E) loop
- Install_Entity (E);
- Next_Entity (E);
- end loop;
-
- Set_Use (Generic_Formal_Declarations (Gen_Decl));
-
- -- Now generic formals are visible, and the specification can be
- -- analyzed, for subsequent conformance check.
-
- Nam := Analyze_Spec (Spec);
-
- if Nkind (N) = N_Subprogram_Body_Stub then
-
- -- Nothing to do if no body to process
-
- Set_Ekind (Nam, Kind);
- End_Scope;
- return;
- end if;
-
- if Present (E) then
-
- -- E is the first formal parameter, which must be the first
- -- entity in the subprogram body.
-
- Set_First_Entity (Gen_Id, E);
-
- -- Now make formal parameters visible
-
- while Present (E) loop
- Install_Entity (E);
- Next_Formal (E);
- end loop;
- end if;
-
- -- Visible generic entity is callable within its own body.
-
- Set_Ekind (Gen_Id, Ekind (Nam));
- Set_Convention (Nam, Convention (Gen_Id));
- Set_Scope (Nam, Scope (Gen_Id));
- Check_Fully_Conformant (Nam, Gen_Id, Nam);
-
- -- If this is a compilation unit, it must be made visible
- -- explicitly, because the compilation of the declaration,
- -- unlike other library unit declarations, does not. If it
- -- is not a unit, the following is redundant but harmless.
-
- Set_Is_Immediately_Visible (Gen_Id);
-
- Set_Actual_Subtypes (N, Current_Scope);
- Analyze_Declarations (Declarations (N));
- Check_Completion;
- Analyze (Handled_Statement_Sequence (N));
-
- Save_Global_References (Original_Node (N));
-
- -- Prior to exiting the scope, include generic formals again
- -- (if any are present) in the set of local entities.
-
- if Present (First_Ent) then
- Set_First_Entity (Gen_Id, First_Ent);
- end if;
-
- end;
-
- End_Scope;
- Check_Subprogram_Order (N);
-
- -- Outside of its body, unit is generic again.
-
- Set_Ekind (Gen_Id, Kind);
- Set_Ekind (Nam, E_Subprogram_Body);
- Generate_Reference (Gen_Id, Nam, 'b');
- Style.Check_Identifier (Nam, Gen_Id);
- End_Generic;
-
- end Analyze_Generic_Subprogram_Body;
-
- -----------------------------
- -- Analyze_Operator_Symbol --
- -----------------------------
-
- -- An operator symbol such as "+" or "and" may appear in context where
- -- the literal denotes an entity name, such as "+"(x, y) or in a
- -- context when it is just a string, as in (conjunction = "or"). In
- -- these cases the parser generates this node, and the semantics does
- -- the disambiguation. Other such case are actuals in an instantiation,
- -- the generic unit in an instantiation, and pragma arguments.
-
- procedure Analyze_Operator_Symbol (N : Node_Id) is
- Par : constant Node_Id := Parent (N);
-
- begin
- if (Nkind (Par) = N_Function_Call and then N = Name (Par))
- or else Nkind (Par) = N_Function_Instantiation
- or else (Nkind (Par) = N_Indexed_Component and then N = Prefix (Par))
- or else (Nkind (Par) = N_Pragma_Argument_Association
- and then not Is_Pragma_String_Literal (Par))
- or else Nkind (Par) = N_Subprogram_Renaming_Declaration
- or else (Nkind (Par) = N_Attribute_Reference
- and then Attribute_Name (Par) /= Name_Value)
- then
- Find_Direct_Name (N);
-
- else
- Change_Operator_Symbol_To_String_Literal (N);
- Analyze (N);
- end if;
- end Analyze_Operator_Symbol;
-
- -----------------------------------
- -- Analyze_Parameter_Association --
- -----------------------------------
-
- procedure Analyze_Parameter_Association (N : Node_Id) is
- begin
- Analyze (Explicit_Actual_Parameter (N));
- end Analyze_Parameter_Association;
-
- ----------------------------
- -- Analyze_Procedure_Call --
- ----------------------------
-
- procedure Analyze_Procedure_Call (N : Node_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- P : constant Node_Id := Name (N);
- Actuals : constant List_Id := Parameter_Associations (N);
- Actual : Node_Id;
- New_N : Node_Id;
-
- procedure Analyze_Call_And_Resolve;
- -- Do Analyze and Resolve calls for procedure call
-
- procedure Analyze_Call_And_Resolve is
- begin
- if Nkind (N) = N_Procedure_Call_Statement then
- Analyze_Call (N);
- Resolve (N, Standard_Void_Type);
- else
- Analyze (N);
- end if;
- end Analyze_Call_And_Resolve;
-
- -- Start of processing for Analyze_Procedure_Call
-
- begin
- -- The syntactic construct: PREFIX ACTUAL_PARAMETER_PART can denote
- -- a procedure call or an entry call. The prefix may denote an access
- -- to subprogram type, in which case an implicit dereference applies.
- -- If the prefix is an indexed component (without implicit defererence)
- -- then the construct denotes a call to a member of an entire family.
- -- If the prefix is a simple name, it may still denote a call to a
- -- parameterless member of an entry family. Resolution of these various
- -- interpretations is delicate.
-
- Analyze (P);
-
- -- If error analyzing prefix, then set Any_Type as result and return
-
- if Etype (P) = Any_Type then
- Set_Etype (N, Any_Type);
- return;
- end if;
-
- -- Otherwise analyze the parameters
-
- if Present (Actuals) then
- Actual := First (Actuals);
-
- while Present (Actual) loop
- Analyze (Actual);
- Check_Parameterless_Call (Actual);
- Next (Actual);
- end loop;
- end if;
-
- -- Special processing for Elab_Spec and Elab_Body calls
-
- if Nkind (P) = N_Attribute_Reference
- and then (Attribute_Name (P) = Name_Elab_Spec
- or else Attribute_Name (P) = Name_Elab_Body)
- then
- if Present (Actuals) then
- Error_Msg_N
- ("no parameters allowed for this call", First (Actuals));
- return;
- end if;
-
- Set_Etype (N, Standard_Void_Type);
- Set_Analyzed (N);
-
- elsif Is_Entity_Name (P)
- and then Is_Record_Type (Etype (Entity (P)))
- and then Remote_AST_I_Dereference (P)
- then
- return;
-
- elsif Is_Entity_Name (P)
- and then Ekind (Entity (P)) /= E_Entry_Family
- then
- if Is_Access_Type (Etype (P))
- and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
- and then No (Actuals)
- and then Comes_From_Source (N)
- then
- Error_Msg_N ("missing explicit dereference in call", N);
- end if;
-
- Analyze_Call_And_Resolve;
-
- -- If the prefix is the simple name of an entry family, this is
- -- a parameterless call from within the task body itself.
-
- elsif Is_Entity_Name (P)
- and then Nkind (P) = N_Identifier
- and then Ekind (Entity (P)) = E_Entry_Family
- and then Present (Actuals)
- and then No (Next (First (Actuals)))
- then
- -- Can be call to parameterless entry family. What appears to be
- -- the sole argument is in fact the entry index. Rewrite prefix
- -- of node accordingly. Source representation is unchanged by this
- -- transformation.
-
- New_N :=
- Make_Indexed_Component (Loc,
- Prefix =>
- Make_Selected_Component (Loc,
- Prefix => New_Occurrence_Of (Scope (Entity (P)), Loc),
- Selector_Name => New_Occurrence_Of (Entity (P), Loc)),
- Expressions => Actuals);
- Set_Name (N, New_N);
- Set_Etype (New_N, Standard_Void_Type);
- Set_Parameter_Associations (N, No_List);
- Analyze_Call_And_Resolve;
-
- elsif Nkind (P) = N_Explicit_Dereference then
- if Ekind (Etype (P)) = E_Subprogram_Type then
- Analyze_Call_And_Resolve;
- else
- Error_Msg_N ("expect access to procedure in call", P);
- end if;
-
- -- The name can be a selected component or an indexed component
- -- that yields an access to subprogram. Such a prefix is legal if
- -- the call has parameter associations.
-
- elsif Is_Access_Type (Etype (P))
- and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type
- then
- if Present (Actuals) then
- Analyze_Call_And_Resolve;
- else
- Error_Msg_N ("missing explicit dereference in call ", N);
- end if;
-
- -- If not an access to subprogram, then the prefix must resolve to
- -- the name of an entry, entry family, or protected operation.
-
- -- For the case of a simple entry call, P is a selected component
- -- where the prefix is the task and the selector name is the entry.
- -- A call to a protected procedure will have the same syntax. If
- -- the protected object contains overloaded operations, the entity
- -- may appear as a function, the context will select the operation
- -- whose type is Void.
-
- elsif Nkind (P) = N_Selected_Component
- and then (Ekind (Entity (Selector_Name (P))) = E_Entry
- or else
- Ekind (Entity (Selector_Name (P))) = E_Procedure
- or else
- Ekind (Entity (Selector_Name (P))) = E_Function)
- then
- Analyze_Call_And_Resolve;
-
- elsif Nkind (P) = N_Selected_Component
- and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family
- and then Present (Actuals)
- and then No (Next (First (Actuals)))
- then
- -- Can be call to parameterless entry family. What appears to be
- -- the sole argument is in fact the entry index. Rewrite prefix
- -- of node accordingly. Source representation is unchanged by this
- -- transformation.
-
- New_N :=
- Make_Indexed_Component (Loc,
- Prefix => New_Copy (P),
- Expressions => Actuals);
- Set_Name (N, New_N);
- Set_Etype (New_N, Standard_Void_Type);
- Set_Parameter_Associations (N, No_List);
- Analyze_Call_And_Resolve;
-
- -- For the case of a reference to an element of an entry family, P is
- -- an indexed component whose prefix is a selected component (task and
- -- entry family), and whose index is the entry family index.
-
- elsif Nkind (P) = N_Indexed_Component
- and then Nkind (Prefix (P)) = N_Selected_Component
- and then Ekind (Entity (Selector_Name (Prefix (P)))) = E_Entry_Family
- then
- Analyze_Call_And_Resolve;
-
- -- If the prefix is the name of an entry family, it is a call from
- -- within the task body itself.
-
- elsif Nkind (P) = N_Indexed_Component
- and then Nkind (Prefix (P)) = N_Identifier
- and then Ekind (Entity (Prefix (P))) = E_Entry_Family
- then
- New_N :=
- Make_Selected_Component (Loc,
- Prefix => New_Occurrence_Of (Scope (Entity (Prefix (P))), Loc),
- Selector_Name => New_Occurrence_Of (Entity (Prefix (P)), Loc));
- Rewrite (Prefix (P), New_N);
- Analyze (P);
- Analyze_Call_And_Resolve;
-
- -- Anything else is an error.
-
- else
- Error_Msg_N ("Invalid procedure or entry call", N);
- end if;
- end Analyze_Procedure_Call;
-
- ------------------------------
- -- Analyze_Return_Statement --
- ------------------------------
-
- procedure Analyze_Return_Statement (N : Node_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- Expr : Node_Id;
- Scope_Id : Entity_Id;
- Kind : Entity_Kind;
- R_Type : Entity_Id;
-
- begin
- -- Find subprogram or accept statement enclosing the return statement
-
- Scope_Id := Empty;
- for J in reverse 0 .. Scope_Stack.Last loop
- Scope_Id := Scope_Stack.Table (J).Entity;
- exit when Ekind (Scope_Id) /= E_Block and then
- Ekind (Scope_Id) /= E_Loop;
- end loop;
-
- pragma Assert (Present (Scope_Id));
-
- Kind := Ekind (Scope_Id);
- Expr := Expression (N);
-
- if Kind /= E_Function
- and then Kind /= E_Generic_Function
- and then Kind /= E_Procedure
- and then Kind /= E_Generic_Procedure
- and then Kind /= E_Entry
- and then Kind /= E_Entry_Family
- then
- Error_Msg_N ("illegal context for return statement", N);
-
- elsif Present (Expr) then
- if Kind = E_Function or else Kind = E_Generic_Function then
- Set_Return_Present (Scope_Id);
- R_Type := Etype (Scope_Id);
- Set_Return_Type (N, R_Type);
- Analyze_And_Resolve (Expr, R_Type);
-
- if (Is_Class_Wide_Type (Etype (Expr))
- or else Is_Dynamically_Tagged (Expr))
- and then not Is_Class_Wide_Type (R_Type)
- then
- Error_Msg_N
- ("dynamically tagged expression not allowed!", Expr);
- end if;
-
- Apply_Constraint_Check (Expr, R_Type);
-
- -- ??? A real run-time accessibility check is needed
- -- in cases involving dereferences of access parameters.
- -- For now we just check the static cases.
-
- if Is_Return_By_Reference_Type (Etype (Scope_Id))
- and then Object_Access_Level (Expr)
- > Subprogram_Access_Level (Scope_Id)
- then
- Rewrite (N, Make_Raise_Program_Error (Loc));
- Analyze (N);
-
- Error_Msg_N
- ("cannot return a local value by reference?", N);
- Error_Msg_NE
- ("& will be raised at run time?!",
- N, Standard_Program_Error);
- end if;
-
- elsif Kind = E_Procedure or else Kind = E_Generic_Procedure then
- Error_Msg_N ("procedure cannot return value (use function)", N);
-
- else
- Error_Msg_N ("accept statement cannot return value", N);
- end if;
-
- -- No expression present
-
- else
- if Kind = E_Function or Kind = E_Generic_Function then
- Error_Msg_N ("missing expression in return from function", N);
- end if;
-
- if (Ekind (Scope_Id) = E_Procedure
- or else Ekind (Scope_Id) = E_Generic_Procedure)
- and then No_Return (Scope_Id)
- then
- Error_Msg_N
- ("RETURN statement not allowed (No_Return)", N);
- end if;
- end if;
-
- Check_Unreachable_Code (N);
- end Analyze_Return_Statement;
-
- ------------------
- -- Analyze_Spec --
- ------------------
-
- function Analyze_Spec (N : Node_Id) return Entity_Id is
- Designator : constant Entity_Id := Defining_Entity (N);
- Formals : constant List_Id := Parameter_Specifications (N);
- Typ : Entity_Id;
-
- begin
- Generate_Definition (Designator);
-
- if Nkind (N) = N_Function_Specification then
- Set_Ekind (Designator, E_Function);
- Set_Mechanism (Designator, Default_Mechanism);
-
- if Subtype_Mark (N) /= Error then
- Find_Type (Subtype_Mark (N));
- Typ := Entity (Subtype_Mark (N));
- Set_Etype (Designator, Typ);
-
- if (Ekind (Typ) = E_Incomplete_Type
- or else (Is_Class_Wide_Type (Typ)
- and then
- Ekind (Root_Type (Typ)) = E_Incomplete_Type))
- then
- Error_Msg_N
- ("invalid use of incomplete type", Subtype_Mark (N));
- end if;
-
- else
- Set_Etype (Designator, Any_Type);
- end if;
-
- else
- Set_Ekind (Designator, E_Procedure);
- Set_Etype (Designator, Standard_Void_Type);
- end if;
-
- if Present (Formals) then
- Set_Scope (Designator, Current_Scope);
- New_Scope (Designator);
- Process_Formals (Designator, Formals, N);
- End_Scope;
- end if;
-
- if Nkind (N) = N_Function_Specification then
- if Nkind (Designator) = N_Defining_Operator_Symbol then
- Valid_Operator_Definition (Designator);
- end if;
-
- May_Need_Actuals (Designator);
-
- if Is_Abstract (Etype (Designator))
- and then Nkind (Parent (N)) /= N_Abstract_Subprogram_Declaration
- then
- Error_Msg_N
- ("function that returns abstract type must be abstract", N);
- end if;
- end if;
-
- return Designator;
- end Analyze_Spec;
-
- -----------------------------
- -- Analyze_Subprogram_Body --
- -----------------------------
-
- -- This procedure is called for regular subprogram bodies, generic bodies,
- -- and for subprogram stubs of both kinds. In the case of stubs, only the
- -- specification matters, and is used to create a proper declaration for
- -- the subprogram, or to perform conformance checks.
-
- procedure Analyze_Subprogram_Body (N : Node_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- Body_Spec : constant Node_Id := Specification (N);
- Body_Id : Entity_Id := Defining_Entity (Body_Spec);
- Prev_Id : constant Entity_Id := Current_Entity_In_Scope (Body_Id);
-
- HSS : Node_Id;
- Spec_Id : Entity_Id;
- Spec_Decl : Node_Id := Empty;
- Last_Formal : Entity_Id := Empty;
- Conformant : Boolean;
- Missing_Ret : Boolean;
- Body_Deleted : Boolean := False;
-
- begin
- if Debug_Flag_C then
- Write_Str ("==== Compiling subprogram body ");
- Write_Name (Chars (Body_Id));
- Write_Str (" from ");
- Write_Location (Loc);
- Write_Eol;
- end if;
-
- Trace_Scope (N, Body_Id, " Analyze subprogram");
-
- -- Generic subprograms are handled separately. They always have
- -- a generic specification. Determine whether current scope has
- -- a previous declaration.
-
- -- If the subprogram body is defined within an instance of the
- -- same name, the instance appears as a package renaming, and
- -- will be hidden within the subprogram.
-
- if Present (Prev_Id)
- and then not Is_Overloadable (Prev_Id)
- and then (Nkind (Parent (Prev_Id)) /= N_Package_Renaming_Declaration
- or else Comes_From_Source (Prev_Id))
- then
- if Ekind (Prev_Id) = E_Generic_Procedure
- or else Ekind (Prev_Id) = E_Generic_Function
- then
- Spec_Id := Prev_Id;
- Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
- Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
-
- Analyze_Generic_Subprogram_Body (N, Spec_Id);
- return;
-
- else
- -- Previous entity conflicts with subprogram name.
- -- Attempting to enter name will post error.
-
- Enter_Name (Body_Id);
- return;
- end if;
-
- -- Non-generic case, find the subprogram declaration, if one was
- -- seen, or enter new overloaded entity in the current scope.
- -- If the current_entity is the body_id itself, the unit is being
- -- analyzed as part of the context of one of its subunits. No need
- -- to redo the analysis.
-
- elsif Prev_Id = Body_Id
- and then Has_Completion (Body_Id)
- then
- return;
-
- else
- Body_Id := Analyze_Spec (Body_Spec);
-
- if Nkind (N) = N_Subprogram_Body_Stub
- or else No (Corresponding_Spec (N))
- then
- Spec_Id := Find_Corresponding_Spec (N);
-
- -- If this is a duplicate body, no point in analyzing it
-
- if Error_Posted (N) then
- return;
- end if;
-
- -- A subprogram body should cause freezing of its own
- -- declaration, but if there was no previous explicit
- -- declaration, then the subprogram will get frozen too
- -- late (there may be code within the body that depends
- -- on the subprogram having been frozen, such as uses of
- -- extra formals), so we force it to be frozen here.
- -- Same holds if the body and the spec are compilation units.
-
- if No (Spec_Id) then
- Freeze_Before (N, Body_Id);
-
- elsif Nkind (Parent (N)) = N_Compilation_Unit then
- Freeze_Before (N, Spec_Id);
- end if;
- else
- Spec_Id := Corresponding_Spec (N);
- end if;
- end if;
-
- if No (Spec_Id)
- and then Comes_From_Source (N)
- and then Is_Protected_Type (Current_Scope)
- then
- -- Fully private operation in the body of the protected type. We
- -- must create a declaration for the subprogram, in order to attach
- -- the protected subprogram that will be used in internal calls.
-
- declare
- Decl : Node_Id;
- Plist : List_Id;
- Formal : Entity_Id;
- New_Spec : Node_Id;
-
- begin
- Formal := First_Formal (Body_Id);
-
- -- The protected operation always has at least one formal,
- -- namely the object itself, but it is only placed in the
- -- parameter list if expansion is enabled.
-
- if Present (Formal)
- or else Expander_Active
- then
- Plist := New_List;
-
- else
- Plist := No_List;
- end if;
-
- while Present (Formal) loop
- Append
- (Make_Parameter_Specification (Loc,
- Defining_Identifier =>
- Make_Defining_Identifier (Sloc (Formal),
- Chars => Chars (Formal)),
- In_Present => In_Present (Parent (Formal)),
- Out_Present => Out_Present (Parent (Formal)),
- Parameter_Type =>
- New_Reference_To (Etype (Formal), Loc),
- Expression =>
- New_Copy_Tree (Expression (Parent (Formal)))),
- Plist);
-
- Next_Formal (Formal);
- end loop;
-
- if Nkind (Body_Spec) = N_Procedure_Specification then
- New_Spec :=
- Make_Procedure_Specification (Loc,
- Defining_Unit_Name =>
- Make_Defining_Identifier (Sloc (Body_Id),
- Chars => Chars (Body_Id)),
- Parameter_Specifications => Plist);
- else
- New_Spec :=
- Make_Function_Specification (Loc,
- Defining_Unit_Name =>
- Make_Defining_Identifier (Sloc (Body_Id),
- Chars => Chars (Body_Id)),
- Parameter_Specifications => Plist,
- Subtype_Mark => New_Occurrence_Of (Etype (Body_Id), Loc));
- end if;
-
- Decl :=
- Make_Subprogram_Declaration (Loc,
- Specification => New_Spec);
- Insert_Before (N, Decl);
- Analyze (Decl);
- Spec_Id := Defining_Unit_Name (New_Spec);
- Set_Has_Completion (Spec_Id);
- Set_Convention (Spec_Id, Convention_Protected);
- end;
-
- elsif Present (Spec_Id) then
- Spec_Decl := Unit_Declaration_Node (Spec_Id);
- end if;
-
- -- Place subprogram on scope stack, and make formals visible. If there
- -- is a spec, the visible entity remains that of the spec.
-
- if Present (Spec_Id) then
- Generate_Reference (Spec_Id, Body_Id, 'b');
- Style.Check_Identifier (Body_Id, Spec_Id);
-
- Set_Is_Compilation_Unit (Body_Id, Is_Compilation_Unit (Spec_Id));
- Set_Is_Child_Unit (Body_Id, Is_Child_Unit (Spec_Id));
-
- if Is_Abstract (Spec_Id) then
- Error_Msg_N ("an abstract subprogram cannot have a body", N);
- return;
- else
- Set_Convention (Body_Id, Convention (Spec_Id));
- Set_Has_Completion (Spec_Id);
-
- if Is_Protected_Type (Scope (Spec_Id)) then
- Set_Privals_Chain (Spec_Id, New_Elmt_List);
- end if;
-
- -- If this is a body generated for a renaming, do not check for
- -- full conformance. The check is redundant, because the spec of
- -- the body is a copy of the spec in the renaming declaration,
- -- and the test can lead to spurious errors on nested defaults.
-
- if Present (Spec_Decl)
- and then Nkind (Original_Node (Spec_Decl)) =
- N_Subprogram_Renaming_Declaration
- and then not Comes_From_Source (N)
- then
- Conformant := True;
- else
- Check_Conformance
- (Body_Id, Spec_Id,
- Fully_Conformant, True, Conformant, Body_Id);
- end if;
-
- -- If the body is not fully conformant, we have to decide if we
- -- should analyze it or not. If it has a really messed up profile
- -- then we probably should not analyze it, since we will get too
- -- many bogus messages.
-
- -- Our decision is to go ahead in the non-fully conformant case
- -- only if it is at least mode conformant with the spec. Note
- -- that the call to Check_Fully_Conformant has issued the proper
- -- error messages to complain about the lack of conformance.
-
- if not Conformant
- and then not Mode_Conformant (Body_Id, Spec_Id)
- then
- return;
- end if;
- end if;
-
- -- Generate references from body formals to spec formals
- -- and also set the Spec_Entity fields for all formals
-
- if Spec_Id /= Body_Id then
- declare
- Fs : Entity_Id;
- Fb : Entity_Id;
-
- begin
- Fs := First_Formal (Spec_Id);
- Fb := First_Formal (Body_Id);
- while Present (Fs) loop
- Generate_Reference (Fs, Fb, 'b');
- Style.Check_Identifier (Fb, Fs);
- Set_Spec_Entity (Fb, Fs);
- Next_Formal (Fs);
- Next_Formal (Fb);
- end loop;
- end;
- end if;
-
- if Nkind (N) /= N_Subprogram_Body_Stub then
- Set_Corresponding_Spec (N, Spec_Id);
- Install_Formals (Spec_Id);
- Last_Formal := Last_Entity (Spec_Id);
- New_Scope (Spec_Id);
-
- -- Make sure that the subprogram is immediately visible. For
- -- child units that have no separate spec this is indispensable.
- -- Otherwise it is safe albeit redundant.
-
- Set_Is_Immediately_Visible (Spec_Id);
- end if;
-
- Set_Corresponding_Body (Unit_Declaration_Node (Spec_Id), Body_Id);
- Set_Ekind (Body_Id, E_Subprogram_Body);
- Set_Scope (Body_Id, Scope (Spec_Id));
-
- -- Case of subprogram body with no previous spec
-
- else
- if Style_Check
- and then Comes_From_Source (Body_Id)
- and then not Suppress_Style_Checks (Body_Id)
- and then not In_Instance
- then
- Style.Body_With_No_Spec (N);
- end if;
-
- New_Overloaded_Entity (Body_Id);
-
- if Nkind (N) /= N_Subprogram_Body_Stub then
- Set_Acts_As_Spec (N);
- Generate_Definition (Body_Id);
- Install_Formals (Body_Id);
- New_Scope (Body_Id);
- end if;
- end if;
-
- -- If this is the proper body of a stub, we must verify that the stub
- -- conforms to the body, and to the previous spec if one was present.
- -- we know already that the body conforms to that spec. This test is
- -- only required for subprograms that come from source.
-
- if Nkind (Parent (N)) = N_Subunit
- and then Comes_From_Source (N)
- and then not Error_Posted (Body_Id)
- then
- declare
- Conformant : Boolean := False;
- Old_Id : Entity_Id :=
- Defining_Entity
- (Specification (Corresponding_Stub (Parent (N))));
-
- begin
- if No (Spec_Id) then
- Check_Fully_Conformant (Body_Id, Old_Id);
-
- else
- Check_Conformance
- (Body_Id, Old_Id, Fully_Conformant, False, Conformant);
-
- if not Conformant then
-
- -- The stub was taken to be a new declaration. Indicate
- -- that it lacks a body.
-
- Set_Has_Completion (Old_Id, False);
- end if;
- end if;
- end;
- end if;
-
- Set_Has_Completion (Body_Id);
- Check_Eliminated (Body_Id);
-
- if Nkind (N) = N_Subprogram_Body_Stub then
- return;
-
- elsif Present (Spec_Id)
- and then Expander_Active
- and then Has_Pragma_Inline (Spec_Id)
- and then (Front_End_Inlining
- or else
- (No_Run_Time and then Is_Always_Inlined (Spec_Id)))
- then
- if Build_Body_To_Inline (N, Spec_Id, Copy_Separate_Tree (N)) then
- null;
- end if;
- end if;
-
- -- Here we have a real body, not a stub. First step is to null out
- -- the subprogram body if we have the special case of no run time
- -- mode with a predefined unit, and the subprogram is not marked
- -- as Inline_Always. The reason is that we should never call such
- -- a routine in no run time mode, and it may in general have some
- -- statements that we cannot handle in no run time mode.
-
- -- ASIS note: we do a replace here, because we are really NOT going
- -- to analyze the original body and declarations at all, so it is
- -- useless to keep them around, we really are obliterating the body,
- -- basically creating a specialized no run time version on the fly
- -- in which the bodies *are* null.
-
- if No_Run_Time
- and then Present (Spec_Id)
- and then Is_Predefined_File_Name
- (Unit_File_Name (Get_Source_Unit (Loc)))
- and then not Is_Always_Inlined (Spec_Id)
- then
- Replace (N,
- Make_Subprogram_Body (Loc,
- Specification => Specification (N),
- Declarations => Empty_List,
- Handled_Statement_Sequence =>
- Make_Handled_Sequence_Of_Statements (Loc,
- Statements => New_List (
- Make_Null_Statement (Loc)),
- End_Label =>
- End_Label (Handled_Statement_Sequence (N)))));
- Set_Corresponding_Spec (N, Spec_Id);
- Body_Deleted := True;
- end if;
-
- -- Now we can go on to analyze the body
-
- HSS := Handled_Statement_Sequence (N);
- Set_Actual_Subtypes (N, Current_Scope);
- Analyze_Declarations (Declarations (N));
- Check_Completion;
- Analyze (HSS);
- Process_End_Label (HSS, 't');
- End_Scope;
- Check_Subprogram_Order (N);
-
- -- If we have a separate spec, then the analysis of the declarations
- -- caused the entities in the body to be chained to the spec id, but
- -- we want them chained to the body id. Only the formal parameters
- -- end up chained to the spec id in this case.
-
- if Present (Spec_Id) then
-
- -- If a parent unit is categorized, the context of a subunit
- -- must conform to the categorization. Conversely, if a child
- -- unit is categorized, the parents themselves must conform.
-
- if Nkind (Parent (N)) = N_Subunit then
- Validate_Categorization_Dependency (N, Spec_Id);
-
- elsif Is_Child_Unit (Spec_Id) then
- Validate_Categorization_Dependency
- (Unit_Declaration_Node (Spec_Id), Spec_Id);
- end if;
-
- if Present (Last_Formal) then
- Set_Next_Entity
- (Last_Entity (Body_Id), Next_Entity (Last_Formal));
- Set_Next_Entity (Last_Formal, Empty);
- Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
- Set_Last_Entity (Spec_Id, Last_Formal);
-
- else
- Set_First_Entity (Body_Id, First_Entity (Spec_Id));
- Set_Last_Entity (Body_Id, Last_Entity (Spec_Id));
- Set_First_Entity (Spec_Id, Empty);
- Set_Last_Entity (Spec_Id, Empty);
- end if;
- end if;
-
- -- If function, check return statements
-
- if Nkind (Body_Spec) = N_Function_Specification then
- declare
- Id : Entity_Id;
-
- begin
- if Present (Spec_Id) then
- Id := Spec_Id;
- else
- Id := Body_Id;
- end if;
-
- if Return_Present (Id) then
- Check_Returns (HSS, 'F', Missing_Ret);
-
- if Missing_Ret then
- Set_Has_Missing_Return (Id);
- end if;
-
- elsif not Is_Machine_Code_Subprogram (Id)
- and then not Body_Deleted
- then
- Error_Msg_N ("missing RETURN statement in function body", N);
- end if;
- end;
-
- -- If procedure with No_Return, check returns
-
- elsif Nkind (Body_Spec) = N_Procedure_Specification
- and then Present (Spec_Id)
- and then No_Return (Spec_Id)
- then
- Check_Returns (HSS, 'P', Missing_Ret);
- end if;
-
- -- Don't worry about checking for variables that are never modified
- -- if the first statement of the body is a raise statement, since
- -- we assume this is some kind of stub. We ignore a label generated
- -- by the exception stuff for the purpose of this test.
-
- declare
- Stm : Node_Id := First (Statements (HSS));
-
- begin
- if Nkind (Stm) = N_Label then
- Next (Stm);
- end if;
-
- if Nkind (Original_Node (Stm)) = N_Raise_Statement then
- return;
- end if;
- end;
-
- -- Check for variables that are never modified
-
- declare
- E1, E2 : Entity_Id;
-
- begin
- -- If there is a separate spec, then transfer Not_Source_Assigned
- -- flags from out parameters to the corresponding entities in the
- -- body. The reason we do that is we want to post error flags on
- -- the body entities, not the spec entities.
-
- if Present (Spec_Id) then
- E1 := First_Entity (Spec_Id);
-
- while Present (E1) loop
- if Ekind (E1) = E_Out_Parameter then
- E2 := First_Entity (Body_Id);
-
- loop
- -- If no matching body entity, then we already had
- -- a detected error of some kind, so just forget
- -- about worrying about these warnings.
-
- if No (E2) then
- return;
- end if;
-
- exit when Chars (E1) = Chars (E2);
- Next_Entity (E2);
- end loop;
-
- Set_Not_Source_Assigned (E2, Not_Source_Assigned (E1));
- end if;
-
- Next_Entity (E1);
- end loop;
- end if;
-
- -- Check references in body unless it was deleted. Note that the
- -- check of Body_Deleted here is not just for efficiency, it is
- -- necessary to avoid junk warnings on formal parameters.
-
- if not Body_Deleted then
- Check_References (Body_Id);
- end if;
- end;
- end Analyze_Subprogram_Body;
-
- ------------------------------------
- -- Analyze_Subprogram_Declaration --
- ------------------------------------
-
- procedure Analyze_Subprogram_Declaration (N : Node_Id) is
- Designator : constant Entity_Id := Analyze_Spec (Specification (N));
- Scop : constant Entity_Id := Current_Scope;
-
- -- Start of processing for Analyze_Subprogram_Declaration
-
- begin
- Generate_Definition (Designator);
-
- -- Check for RCI unit subprogram declarations against in-lined
- -- subprograms and subprograms having access parameter or limited
- -- parameter without Read and Write (RM E.2.3(12-13)).
-
- Validate_RCI_Subprogram_Declaration (N);
-
- Trace_Scope
- (N,
- Defining_Entity (N),
- " Analyze subprogram spec. ");
-
- if Debug_Flag_C then
- Write_Str ("==== Compiling subprogram spec ");
- Write_Name (Chars (Designator));
- Write_Str (" from ");
- Write_Location (Sloc (N));
- Write_Eol;
- end if;
-
- New_Overloaded_Entity (Designator);
- Check_Delayed_Subprogram (Designator);
- Set_Suppress_Elaboration_Checks
- (Designator, Elaboration_Checks_Suppressed (Designator));
-
- if Scop /= Standard_Standard
- and then not Is_Child_Unit (Designator)
- then
- Set_Is_Pure (Designator,
- Is_Pure (Scop) and then Is_Library_Level_Entity (Designator));
- Set_Is_Remote_Call_Interface (
- Designator, Is_Remote_Call_Interface (Scop));
- Set_Is_Remote_Types (Designator, Is_Remote_Types (Scop));
-
- else
- -- For a compilation unit, check for library-unit pragmas.
-
- New_Scope (Designator);
- Set_Categorization_From_Pragmas (N);
- Validate_Categorization_Dependency (N, Designator);
- Pop_Scope;
- end if;
-
- -- For a compilation unit, set body required. This flag will only be
- -- reset if a valid Import or Interface pragma is processed later on.
-
- if Nkind (Parent (N)) = N_Compilation_Unit then
- Set_Body_Required (Parent (N), True);
- end if;
-
- Check_Eliminated (Designator);
- end Analyze_Subprogram_Declaration;
-
- --------------------------
- -- Build_Body_To_Inline --
- --------------------------
-
- function Build_Body_To_Inline
- (N : Node_Id;
- Subp : Entity_Id;
- Orig_Body : Node_Id) return Boolean
- is
- Decl : constant Node_Id := Unit_Declaration_Node (Subp);
- Original_Body : Node_Id;
- Body_To_Analyze : Node_Id;
- Max_Size : constant := 10;
- Stat_Count : Integer := 0;
-
- function Has_Excluded_Declaration (Decls : List_Id) return Boolean;
- -- Check for declarations that make inlining not worthwhile.
-
- function Has_Excluded_Statement (Stats : List_Id) return Boolean;
- -- Check for statements that make inlining not worthwhile: any
- -- tasking statement, nested at any level. Keep track of total
- -- number of elementary statements, as a measure of acceptable size.
-
- function Has_Pending_Instantiation return Boolean;
- -- If some enclosing body contains instantiations that appear before
- -- the corresponding generic body, the enclosing body has a freeze node
- -- so that it can be elaborated after the generic itself. This might
- -- conflict with subsequent inlinings, so that it is unsafe to try to
- -- inline in such a case.
-
- -------------------
- -- Cannot_Inline --
- -------------------
-
- procedure Cannot_Inline (Msg : String; N : Node_Id);
- -- If subprogram has pragma Inline_Always, it is an error if
- -- it cannot be inlined. Otherwise, emit a warning.
-
- procedure Cannot_Inline (Msg : String; N : Node_Id) is
- begin
- if Is_Always_Inlined (Subp) then
- Error_Msg_NE (Msg (1 .. Msg'Length - 1), N, Subp);
-
- elsif Ineffective_Inline_Warnings then
- Error_Msg_NE (Msg, N, Subp);
- end if;
- end Cannot_Inline;
-
- ------------------------------
- -- Has_Excluded_Declaration --
- ------------------------------
-
- function Has_Excluded_Declaration (Decls : List_Id) return Boolean is
- D : Node_Id;
-
- begin
- D := First (Decls);
-
- while Present (D) loop
- if Nkind (D) = N_Function_Instantiation
- or else Nkind (D) = N_Protected_Type_Declaration
- or else Nkind (D) = N_Package_Declaration
- or else Nkind (D) = N_Package_Instantiation
- or else Nkind (D) = N_Subprogram_Body
- or else Nkind (D) = N_Procedure_Instantiation
- or else Nkind (D) = N_Task_Type_Declaration
- then
- Cannot_Inline
- ("\declaration prevents front-end inlining of&?", D);
- return True;
- end if;
-
- Next (D);
- end loop;
-
- return False;
-
- end Has_Excluded_Declaration;
-
- ----------------------------
- -- Has_Excluded_Statement --
- ----------------------------
-
- function Has_Excluded_Statement (Stats : List_Id) return Boolean is
- S : Node_Id;
- E : Node_Id;
-
- begin
- S := First (Stats);
-
- while Present (S) loop
- Stat_Count := Stat_Count + 1;
-
- if Nkind (S) = N_Abort_Statement
- or else Nkind (S) = N_Asynchronous_Select
- or else Nkind (S) = N_Conditional_Entry_Call
- or else Nkind (S) = N_Delay_Relative_Statement
- or else Nkind (S) = N_Delay_Until_Statement
- or else Nkind (S) = N_Selective_Accept
- or else Nkind (S) = N_Timed_Entry_Call
- then
- Cannot_Inline
- ("\statement prevents front-end inlining of&?", S);
- return True;
-
- elsif Nkind (S) = N_Block_Statement then
- if Present (Declarations (S))
- and then Has_Excluded_Declaration (Declarations (S))
- then
- return True;
-
- elsif Present (Handled_Statement_Sequence (S))
- and then
- (Present
- (Exception_Handlers (Handled_Statement_Sequence (S)))
- or else
- Has_Excluded_Statement
- (Statements (Handled_Statement_Sequence (S))))
- then
- return True;
- end if;
-
- elsif Nkind (S) = N_Case_Statement then
- E := First (Alternatives (S));
-
- while Present (E) loop
- if Has_Excluded_Statement (Statements (E)) then
- return True;
- end if;
-
- Next (E);
- end loop;
-
- elsif Nkind (S) = N_If_Statement then
- if Has_Excluded_Statement (Then_Statements (S)) then
- return True;
- end if;
-
- if Present (Elsif_Parts (S)) then
- E := First (Elsif_Parts (S));
-
- while Present (E) loop
- if Has_Excluded_Statement (Then_Statements (E)) then
- return True;
- end if;
- Next (E);
- end loop;
- end if;
-
- if Present (Else_Statements (S))
- and then Has_Excluded_Statement (Else_Statements (S))
- then
- return True;
- end if;
-
- elsif Nkind (S) = N_Loop_Statement
- and then Has_Excluded_Statement (Statements (S))
- then
- return True;
- end if;
-
- Next (S);
- end loop;
-
- return False;
- end Has_Excluded_Statement;
-
- -------------------------------
- -- Has_Pending_Instantiation --
- -------------------------------
-
- function Has_Pending_Instantiation return Boolean is
- S : Entity_Id := Current_Scope;
-
- begin
- while Present (S) loop
- if Is_Compilation_Unit (S)
- or else Is_Child_Unit (S)
- then
- return False;
- elsif Ekind (S) = E_Package
- and then Has_Forward_Instantiation (S)
- then
- return True;
- end if;
-
- S := Scope (S);
- end loop;
-
- return False;
- end Has_Pending_Instantiation;
-
- -- Start of processing for Build_Body_To_Inline
-
- begin
- if Nkind (Decl) = N_Subprogram_Declaration
- and then Present (Body_To_Inline (Decl))
- then
- return True; -- Done already.
-
- -- Functions that return unconstrained composite types will require
- -- secondary stack handling, and cannot currently be inlined.
-
- elsif Ekind (Subp) = E_Function
- and then not Is_Scalar_Type (Etype (Subp))
- and then not Is_Access_Type (Etype (Subp))
- and then not Is_Constrained (Etype (Subp))
- then
- Cannot_Inline
- ("unconstrained return type prevents front-end inlining of&?", N);
- return False;
- end if;
-
- -- We need to capture references to the formals in order to substitute
- -- the actuals at the point of inlining, i.e. instantiation. To treat
- -- the formals as globals to the body to inline, we nest it within
- -- a dummy parameterless subprogram, declared within the real one.
-
- Original_Body := Orig_Body;
-
- -- Within an instance, the current tree is already the result of
- -- a generic copy, and not what we need for subsequent inlining.
- -- We create the required body by doing an instantiating copy, to
- -- obtain the proper partially analyzed tree.
-
- if In_Instance then
- if No (Generic_Parent (Specification (N))) then
- return False;
-
- elsif Is_Child_Unit (Scope (Current_Scope)) then
- return False;
-
- elsif Scope (Current_Scope) = Cunit_Entity (Main_Unit) then
-
- -- compiling an instantiation. There is no point in generating
- -- bodies to inline, because they will not be used.
-
- return False;
-
- else
- Body_To_Analyze :=
- Copy_Generic_Node
- (Generic_Parent (Specification (N)), Empty,
- Instantiating => True);
- end if;
- else
- Body_To_Analyze :=
- Copy_Generic_Node (Original_Body, Empty,
- Instantiating => False);
- end if;
-
- Set_Parameter_Specifications (Specification (Original_Body), No_List);
- Set_Defining_Unit_Name (Specification (Original_Body),
- Make_Defining_Identifier (Sloc (N), New_Internal_Name ('S')));
- Set_Corresponding_Spec (Original_Body, Empty);
-
- if Ekind (Subp) = E_Function then
- Set_Subtype_Mark (Specification (Original_Body),
- New_Occurrence_Of (Etype (Subp), Sloc (N)));
- end if;
-
- if Present (Declarations (Orig_Body))
- and then Has_Excluded_Declaration (Declarations (Orig_Body))
- then
- return False;
- end if;
-
- if Present (Handled_Statement_Sequence (N)) then
- if
- (Present (Exception_Handlers (Handled_Statement_Sequence (N))))
- then
- Cannot_Inline ("handler prevents front-end inlining of&?",
- First (Exception_Handlers (Handled_Statement_Sequence (N))));
- return False;
- elsif
- Has_Excluded_Statement
- (Statements (Handled_Statement_Sequence (N)))
- then
- return False;
- end if;
- end if;
-
- -- We do not inline a subprogram that is too large, unless it is
- -- marked Inline_Always. This pragma does not suppress the other
- -- checks on inlining (forbidden declarations, handlers, etc).
-
- if Stat_Count > Max_Size
- and then not Is_Always_Inlined (Subp)
- then
- Cannot_Inline ("body is too large for front-end inlining of&?", N);
- return False;
- end if;
-
- if Has_Pending_Instantiation then
- Cannot_Inline
- ("cannot inline& because of forward instance within enclosing body",
- N);
- return False;
- end if;
-
- Body_To_Analyze := Copy_Generic_Node (Original_Body, Empty, False);
-
- -- Set return type of function, which is also global and does not need
- -- to be resolved.
-
- if Ekind (Subp) = E_Function then
- Set_Subtype_Mark (Specification (Body_To_Analyze),
- New_Occurrence_Of (Etype (Subp), Sloc (N)));
- end if;
-
- if No (Declarations (N)) then
- Set_Declarations (N, New_List (Body_To_Analyze));
- else
- Append (Body_To_Analyze, Declarations (N));
- end if;
-
- Expander_Mode_Save_And_Set (False);
-
- Analyze (Body_To_Analyze);
- New_Scope (Defining_Entity (Body_To_Analyze));
- Save_Global_References (Original_Body);
- End_Scope;
- Remove (Body_To_Analyze);
-
- Expander_Mode_Restore;
- Set_Body_To_Inline (Decl, Original_Body);
- Set_Is_Inlined (Subp);
- return True;
-
- end Build_Body_To_Inline;
-
- -----------------------
- -- Check_Conformance --
- -----------------------
-
- procedure Check_Conformance
- (New_Id : Entity_Id;
- Old_Id : Entity_Id;
- Ctype : Conformance_Type;
- Errmsg : Boolean;
- Conforms : out Boolean;
- Err_Loc : Node_Id := Empty;
- Get_Inst : Boolean := False)
- is
- Old_Type : constant Entity_Id := Etype (Old_Id);
- New_Type : constant Entity_Id := Etype (New_Id);
- Old_Formal : Entity_Id;
- New_Formal : Entity_Id;
-
- procedure Conformance_Error (Msg : String; N : Node_Id := New_Id);
- -- Post error message for conformance error on given node.
- -- Two messages are output. The first points to the previous
- -- declaration with a general "no conformance" message.
- -- The second is the detailed reason, supplied as Msg. The
- -- parameter N provide information for a possible & insertion
- -- in the message, and also provides the location for posting
- -- the message in the absence of a specified Err_Loc location.
-
- -----------------------
- -- Conformance_Error --
- -----------------------
-
- procedure Conformance_Error (Msg : String; N : Node_Id := New_Id) is
- Enode : Node_Id;
-
- begin
- Conforms := False;
-
- if Errmsg then
- if No (Err_Loc) then
- Enode := N;
- else
- Enode := Err_Loc;
- end if;
-
- Error_Msg_Sloc := Sloc (Old_Id);
-
- case Ctype is
- when Type_Conformant =>
- Error_Msg_N
- ("not type conformant with declaration#!", Enode);
-
- when Mode_Conformant =>
- Error_Msg_N
- ("not mode conformant with declaration#!", Enode);
-
- when Subtype_Conformant =>
- Error_Msg_N
- ("not subtype conformant with declaration#!", Enode);
-
- when Fully_Conformant =>
- Error_Msg_N
- ("not fully conformant with declaration#!", Enode);
- end case;
-
- Error_Msg_NE (Msg, Enode, N);
- end if;
- end Conformance_Error;
-
- -- Start of processing for Check_Conformance
-
- begin
- Conforms := True;
-
- -- We need a special case for operators, since they don't
- -- appear explicitly.
-
- if Ctype = Type_Conformant then
- if Ekind (New_Id) = E_Operator
- and then Operator_Matches_Spec (New_Id, Old_Id)
- then
- return;
- end if;
- end if;
-
- -- If both are functions/operators, check return types conform
-
- if Old_Type /= Standard_Void_Type
- and then New_Type /= Standard_Void_Type
- then
- if not Conforming_Types (Old_Type, New_Type, Ctype, Get_Inst) then
- Conformance_Error ("return type does not match!", New_Id);
- return;
- end if;
-
- -- If either is a function/operator and the other isn't, error
-
- elsif Old_Type /= Standard_Void_Type
- or else New_Type /= Standard_Void_Type
- then
- Conformance_Error ("functions can only match functions!", New_Id);
- return;
- end if;
-
- -- In subtype conformant case, conventions must match (RM 6.3.1(16))
- -- If this is a renaming as body, refine error message to indicate that
- -- the conflict is with the original declaration. If the entity is not
- -- frozen, the conventions don't have to match, the one of the renamed
- -- entity is inherited.
-
- if Ctype >= Subtype_Conformant then
-
- if Convention (Old_Id) /= Convention (New_Id) then
-
- if not Is_Frozen (New_Id) then
- null;
-
- elsif Present (Err_Loc)
- and then Nkind (Err_Loc) = N_Subprogram_Renaming_Declaration
- and then Present (Corresponding_Spec (Err_Loc))
- then
- Error_Msg_Name_1 := Chars (New_Id);
- Error_Msg_Name_2 :=
- Name_Ada + Convention_Id'Pos (Convention (New_Id));
-
- Conformance_Error ("prior declaration for% has convention %!");
-
- else
- Conformance_Error ("calling conventions do not match!");
- end if;
-
- return;
-
- elsif Is_Formal_Subprogram (Old_Id)
- or else Is_Formal_Subprogram (New_Id)
- then
- Conformance_Error ("formal subprograms not allowed!");
- return;
- end if;
- end if;
-
- -- Deal with parameters
-
- -- Note: we use the entity information, rather than going directly
- -- to the specification in the tree. This is not only simpler, but
- -- absolutely necessary for some cases of conformance tests between
- -- operators, where the declaration tree simply does not exist!
-
- Old_Formal := First_Formal (Old_Id);
- New_Formal := First_Formal (New_Id);
-
- while Present (Old_Formal) and then Present (New_Formal) loop
-
- -- Types must always match. In the visible part of an instance,
- -- usual overloading rules for dispatching operations apply, and
- -- we check base types (not the actual subtypes).
-
- if In_Instance_Visible_Part
- and then Is_Dispatching_Operation (New_Id)
- then
- if not Conforming_Types
- (Base_Type (Etype (Old_Formal)),
- Base_Type (Etype (New_Formal)), Ctype, Get_Inst)
- then
- Conformance_Error ("type of & does not match!", New_Formal);
- return;
- end if;
-
- elsif not Conforming_Types
- (Etype (Old_Formal), Etype (New_Formal), Ctype, Get_Inst)
- then
- Conformance_Error ("type of & does not match!", New_Formal);
- return;
- end if;
-
- -- For mode conformance, mode must match
-
- if Ctype >= Mode_Conformant
- and then Parameter_Mode (Old_Formal) /= Parameter_Mode (New_Formal)
- then
- Conformance_Error ("mode of & does not match!", New_Formal);
- return;
- end if;
-
- -- Full conformance checks
-
- if Ctype = Fully_Conformant then
-
- -- Names must match
-
- if Chars (Old_Formal) /= Chars (New_Formal) then
- Conformance_Error ("name & does not match!", New_Formal);
- return;
-
- -- And default expressions for in parameters
-
- elsif Parameter_Mode (Old_Formal) = E_In_Parameter then
- declare
- NewD : constant Boolean :=
- Present (Default_Value (New_Formal));
- OldD : constant Boolean :=
- Present (Default_Value (Old_Formal));
- begin
- if NewD or OldD then
-
- -- The old default value has been analyzed and expanded,
- -- because the current full declaration will have frozen
- -- everything before. The new default values have not
- -- been expanded, so expand now to check conformance.
-
- if NewD then
- New_Scope (New_Id);
- Analyze_Default_Expression
- (Default_Value (New_Formal), Etype (New_Formal));
- End_Scope;
- end if;
-
- if not (NewD and OldD)
- or else not Fully_Conformant_Expressions
- (Default_Value (Old_Formal),
- Default_Value (New_Formal))
- then
- Conformance_Error
- ("default expression for & does not match!",
- New_Formal);
- return;
- end if;
- end if;
- end;
- end if;
- end if;
-
- -- A couple of special checks for Ada 83 mode. These checks are
- -- skipped if either entity is an operator in package Standard.
- -- or if either old or new instance is not from the source program.
-
- if Ada_83
- and then Sloc (Old_Id) > Standard_Location
- and then Sloc (New_Id) > Standard_Location
- and then Comes_From_Source (Old_Id)
- and then Comes_From_Source (New_Id)
- then
- declare
- Old_Param : constant Node_Id := Declaration_Node (Old_Formal);
- New_Param : constant Node_Id := Declaration_Node (New_Formal);
-
- begin
- -- Explicit IN must be present or absent in both cases. This
- -- test is required only in the full conformance case.
-
- if In_Present (Old_Param) /= In_Present (New_Param)
- and then Ctype = Fully_Conformant
- then
- Conformance_Error
- ("(Ada 83) IN must appear in both declarations",
- New_Formal);
- return;
- end if;
-
- -- Grouping (use of comma in param lists) must be the same
- -- This is where we catch a misconformance like:
-
- -- A,B : Integer
- -- A : Integer; B : Integer
-
- -- which are represented identically in the tree except
- -- for the setting of the flags More_Ids and Prev_Ids.
-
- if More_Ids (Old_Param) /= More_Ids (New_Param)
- or else Prev_Ids (Old_Param) /= Prev_Ids (New_Param)
- then
- Conformance_Error
- ("grouping of & does not match!", New_Formal);
- return;
- end if;
- end;
- end if;
-
- Next_Formal (Old_Formal);
- Next_Formal (New_Formal);
- end loop;
-
- if Present (Old_Formal) then
- Conformance_Error ("too few parameters!");
- return;
-
- elsif Present (New_Formal) then
- Conformance_Error ("too many parameters!", New_Formal);
- return;
- end if;
-
- end Check_Conformance;
-
- ------------------------------
- -- Check_Delayed_Subprogram --
- ------------------------------
-
- procedure Check_Delayed_Subprogram (Designator : Entity_Id) is
- F : Entity_Id;
-
- procedure Possible_Freeze (T : Entity_Id);
- -- T is the type of either a formal parameter or of the return type.
- -- If T is not yet frozen and needs a delayed freeze, then the
- -- subprogram itself must be delayed.
-
- procedure Possible_Freeze (T : Entity_Id) is
- begin
- if Has_Delayed_Freeze (T)
- and then not Is_Frozen (T)
- then
- Set_Has_Delayed_Freeze (Designator);
-
- elsif Is_Access_Type (T)
- and then Has_Delayed_Freeze (Designated_Type (T))
- and then not Is_Frozen (Designated_Type (T))
- then
- Set_Has_Delayed_Freeze (Designator);
- end if;
- end Possible_Freeze;
-
- -- Start of processing for Check_Delayed_Subprogram
-
- begin
- -- Never need to freeze abstract subprogram
-
- if Is_Abstract (Designator) then
- null;
- else
- -- Need delayed freeze if return type itself needs a delayed
- -- freeze and is not yet frozen.
-
- Possible_Freeze (Etype (Designator));
- Possible_Freeze (Base_Type (Etype (Designator))); -- needed ???
-
- -- Need delayed freeze if any of the formal types themselves need
- -- a delayed freeze and are not yet frozen.
-
- F := First_Formal (Designator);
- while Present (F) loop
- Possible_Freeze (Etype (F));
- Possible_Freeze (Base_Type (Etype (F))); -- needed ???
- Next_Formal (F);
- end loop;
- end if;
-
- -- Mark functions that return by reference. Note that it cannot be
- -- done for delayed_freeze subprograms because the underlying
- -- returned type may not be known yet (for private types)
-
- if not Has_Delayed_Freeze (Designator)
- and then Expander_Active
- then
- declare
- Typ : constant Entity_Id := Etype (Designator);
- Utyp : constant Entity_Id := Underlying_Type (Typ);
-
- begin
- if Is_Return_By_Reference_Type (Typ) then
- Set_Returns_By_Ref (Designator);
-
- elsif Present (Utyp) and then Controlled_Type (Utyp) then
- Set_Returns_By_Ref (Designator);
- end if;
- end;
- end if;
- end Check_Delayed_Subprogram;
-
- ------------------------------------
- -- Check_Discriminant_Conformance --
- ------------------------------------
-
- procedure Check_Discriminant_Conformance
- (N : Node_Id;
- Prev : Entity_Id;
- Prev_Loc : Node_Id)
- is
- Old_Discr : Entity_Id := First_Discriminant (Prev);
- New_Discr : Node_Id := First (Discriminant_Specifications (N));
- New_Discr_Id : Entity_Id;
- New_Discr_Type : Entity_Id;
-
- procedure Conformance_Error (Msg : String; N : Node_Id);
- -- Post error message for conformance error on given node.
- -- Two messages are output. The first points to the previous
- -- declaration with a general "no conformance" message.
- -- The second is the detailed reason, supplied as Msg. The
- -- parameter N provide information for a possible & insertion
- -- in the message.
-
- -----------------------
- -- Conformance_Error --
- -----------------------
-
- procedure Conformance_Error (Msg : String; N : Node_Id) is
- begin
- Error_Msg_Sloc := Sloc (Prev_Loc);
- Error_Msg_N ("not fully conformant with declaration#!", N);
- Error_Msg_NE (Msg, N, N);
- end Conformance_Error;
-
- -- Start of processing for Check_Discriminant_Conformance
-
- begin
- while Present (Old_Discr) and then Present (New_Discr) loop
-
- New_Discr_Id := Defining_Identifier (New_Discr);
-
- -- The subtype mark of the discriminant on the full type
- -- has not been analyzed so we do it here. For an access
- -- discriminant a new type is created.
-
- if Nkind (Discriminant_Type (New_Discr)) = N_Access_Definition then
- New_Discr_Type :=
- Access_Definition (N, Discriminant_Type (New_Discr));
-
- else
- Analyze (Discriminant_Type (New_Discr));
- New_Discr_Type := Etype (Discriminant_Type (New_Discr));
- end if;
-
- if not Conforming_Types
- (Etype (Old_Discr), New_Discr_Type, Fully_Conformant)
- then
- Conformance_Error ("type of & does not match!", New_Discr_Id);
- return;
- end if;
-
- -- Names must match
-
- if Chars (Old_Discr) /= Chars (Defining_Identifier (New_Discr)) then
- Conformance_Error ("name & does not match!", New_Discr_Id);
- return;
- end if;
-
- -- Default expressions must match
-
- declare
- NewD : constant Boolean :=
- Present (Expression (New_Discr));
- OldD : constant Boolean :=
- Present (Expression (Parent (Old_Discr)));
-
- begin
- if NewD or OldD then
-
- -- The old default value has been analyzed and expanded,
- -- because the current full declaration will have frozen
- -- everything before. The new default values have not
- -- been expanded, so expand now to check conformance.
-
- if NewD then
- Analyze_Default_Expression
- (Expression (New_Discr), New_Discr_Type);
- end if;
-
- if not (NewD and OldD)
- or else not Fully_Conformant_Expressions
- (Expression (Parent (Old_Discr)),
- Expression (New_Discr))
-
- then
- Conformance_Error
- ("default expression for & does not match!",
- New_Discr_Id);
- return;
- end if;
- end if;
- end;
-
- -- In Ada 83 case, grouping must match: (A,B : X) /= (A : X; B : X)
-
- if Ada_83 then
- declare
- Old_Disc : constant Node_Id := Declaration_Node (Old_Discr);
-
- begin
- -- Grouping (use of comma in param lists) must be the same
- -- This is where we catch a misconformance like:
-
- -- A,B : Integer
- -- A : Integer; B : Integer
-
- -- which are represented identically in the tree except
- -- for the setting of the flags More_Ids and Prev_Ids.
-
- if More_Ids (Old_Disc) /= More_Ids (New_Discr)
- or else Prev_Ids (Old_Disc) /= Prev_Ids (New_Discr)
- then
- Conformance_Error
- ("grouping of & does not match!", New_Discr_Id);
- return;
- end if;
- end;
- end if;
-
- Next_Discriminant (Old_Discr);
- Next (New_Discr);
- end loop;
-
- if Present (Old_Discr) then
- Conformance_Error ("too few discriminants!", Defining_Identifier (N));
- return;
-
- elsif Present (New_Discr) then
- Conformance_Error
- ("too many discriminants!", Defining_Identifier (New_Discr));
- return;
- end if;
- end Check_Discriminant_Conformance;
-
- ----------------------------
- -- Check_Fully_Conformant --
- ----------------------------
-
- procedure Check_Fully_Conformant
- (New_Id : Entity_Id;
- Old_Id : Entity_Id;
- Err_Loc : Node_Id := Empty)
- is
- Result : Boolean;
-
- begin
- Check_Conformance
- (New_Id, Old_Id, Fully_Conformant, True, Result, Err_Loc);
- end Check_Fully_Conformant;
-
- ---------------------------
- -- Check_Mode_Conformant --
- ---------------------------
-
- procedure Check_Mode_Conformant
- (New_Id : Entity_Id;
- Old_Id : Entity_Id;
- Err_Loc : Node_Id := Empty;
- Get_Inst : Boolean := False)
- is
- Result : Boolean;
-
- begin
- Check_Conformance
- (New_Id, Old_Id, Mode_Conformant, True, Result, Err_Loc, Get_Inst);
- end Check_Mode_Conformant;
-
- -------------------
- -- Check_Returns --
- -------------------
-
- procedure Check_Returns
- (HSS : Node_Id;
- Mode : Character;
- Err : out Boolean)
- is
- Handler : Node_Id;
-
- procedure Check_Statement_Sequence (L : List_Id);
- -- Internal recursive procedure to check a list of statements for proper
- -- termination by a return statement (or a transfer of control or a
- -- compound statement that is itself internally properly terminated).
-
- ------------------------------
- -- Check_Statement_Sequence --
- ------------------------------
-
- procedure Check_Statement_Sequence (L : List_Id) is
- Last_Stm : Node_Id;
- Kind : Node_Kind;
-
- Raise_Exception_Call : Boolean;
- -- Set True if statement sequence terminated by Raise_Exception call
- -- or a Reraise_Occurrence call.
-
- begin
- Raise_Exception_Call := False;
-
- -- Get last real statement
-
- Last_Stm := Last (L);
-
- -- Don't count pragmas
-
- while Nkind (Last_Stm) = N_Pragma
-
- -- Don't count call to SS_Release (can happen after Raise_Exception)
-
- or else
- (Nkind (Last_Stm) = N_Procedure_Call_Statement
- and then
- Nkind (Name (Last_Stm)) = N_Identifier
- and then
- Is_RTE (Entity (Name (Last_Stm)), RE_SS_Release))
-
- -- Don't count exception junk
-
- or else
- ((Nkind (Last_Stm) = N_Goto_Statement
- or else Nkind (Last_Stm) = N_Label
- or else Nkind (Last_Stm) = N_Object_Declaration)
- and then Exception_Junk (Last_Stm))
- loop
- Prev (Last_Stm);
- end loop;
-
- -- Here we have the "real" last statement
-
- Kind := Nkind (Last_Stm);
-
- -- Transfer of control, OK. Note that in the No_Return procedure
- -- case, we already diagnosed any explicit return statements, so
- -- we can treat them as OK in this context.
-
- if Is_Transfer (Last_Stm) then
- return;
-
- -- Check cases of explicit non-indirect procedure calls
-
- elsif Kind = N_Procedure_Call_Statement
- and then Is_Entity_Name (Name (Last_Stm))
- then
- -- Check call to Raise_Exception procedure which is treated
- -- specially, as is a call to Reraise_Occurrence.
-
- -- We suppress the warning in these cases since it is likely that
- -- the programmer really does not expect to deal with the case
- -- of Null_Occurrence, and thus would find a warning about a
- -- missing return curious, and raising Program_Error does not
- -- seem such a bad behavior if this does occur.
-
- if Is_RTE (Entity (Name (Last_Stm)), RE_Raise_Exception)
- or else
- Is_RTE (Entity (Name (Last_Stm)), RE_Reraise_Occurrence)
- then
- Raise_Exception_Call := True;
-
- -- For Raise_Exception call, test first argument, if it is
- -- an attribute reference for a 'Identity call, then we know
- -- that the call cannot possibly return.
-
- declare
- Arg : constant Node_Id :=
- Original_Node (First_Actual (Last_Stm));
-
- begin
- if Nkind (Arg) = N_Attribute_Reference
- and then Attribute_Name (Arg) = Name_Identity
- then
- return;
- end if;
- end;
- end if;
-
- -- If statement, need to look inside if there is an else and check
- -- each constituent statement sequence for proper termination.
-
- elsif Kind = N_If_Statement
- and then Present (Else_Statements (Last_Stm))
- then
- Check_Statement_Sequence (Then_Statements (Last_Stm));
- Check_Statement_Sequence (Else_Statements (Last_Stm));
-
- if Present (Elsif_Parts (Last_Stm)) then
- declare
- Elsif_Part : Node_Id := First (Elsif_Parts (Last_Stm));
-
- begin
- while Present (Elsif_Part) loop
- Check_Statement_Sequence (Then_Statements (Elsif_Part));
- Next (Elsif_Part);
- end loop;
- end;
- end if;
-
- return;
-
- -- Case statement, check each case for proper termination
-
- elsif Kind = N_Case_Statement then
- declare
- Case_Alt : Node_Id;
-
- begin
- Case_Alt := First_Non_Pragma (Alternatives (Last_Stm));
- while Present (Case_Alt) loop
- Check_Statement_Sequence (Statements (Case_Alt));
- Next_Non_Pragma (Case_Alt);
- end loop;
- end;
-
- return;
-
- -- Block statement, check its handled sequence of statements
-
- elsif Kind = N_Block_Statement then
- declare
- Err1 : Boolean;
-
- begin
- Check_Returns
- (Handled_Statement_Sequence (Last_Stm), Mode, Err1);
-
- if Err1 then
- Err := True;
- end if;
-
- return;
- end;
-
- -- Loop statement. If there is an iteration scheme, we can definitely
- -- fall out of the loop. Similarly if there is an exit statement, we
- -- can fall out. In either case we need a following return.
-
- elsif Kind = N_Loop_Statement then
- if Present (Iteration_Scheme (Last_Stm))
- or else Has_Exit (Entity (Identifier (Last_Stm)))
- then
- null;
-
- -- A loop with no exit statement or iteration scheme if either
- -- an inifite loop, or it has some other exit (raise/return).
- -- In either case, no warning is required.
-
- else
- return;
- end if;
-
- -- Timed entry call, check entry call and delay alternatives
-
- -- Note: in expanded code, the timed entry call has been converted
- -- to a set of expanded statements on which the check will work
- -- correctly in any case.
-
- elsif Kind = N_Timed_Entry_Call then
- declare
- ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
- DCA : constant Node_Id := Delay_Alternative (Last_Stm);
-
- begin
- -- If statement sequence of entry call alternative is missing,
- -- then we can definitely fall through, and we post the error
- -- message on the entry call alternative itself.
-
- if No (Statements (ECA)) then
- Last_Stm := ECA;
-
- -- If statement sequence of delay alternative is missing, then
- -- we can definitely fall through, and we post the error
- -- message on the delay alternative itself.
-
- -- Note: if both ECA and DCA are missing the return, then we
- -- post only one message, should be enough to fix the bugs.
- -- If not we will get a message next time on the DCA when the
- -- ECA is fixed!
-
- elsif No (Statements (DCA)) then
- Last_Stm := DCA;
-
- -- Else check both statement sequences
-
- else
- Check_Statement_Sequence (Statements (ECA));
- Check_Statement_Sequence (Statements (DCA));
- return;
- end if;
- end;
-
- -- Conditional entry call, check entry call and else part
-
- -- Note: in expanded code, the conditional entry call has been
- -- converted to a set of expanded statements on which the check
- -- will work correctly in any case.
-
- elsif Kind = N_Conditional_Entry_Call then
- declare
- ECA : constant Node_Id := Entry_Call_Alternative (Last_Stm);
-
- begin
- -- If statement sequence of entry call alternative is missing,
- -- then we can definitely fall through, and we post the error
- -- message on the entry call alternative itself.
-
- if No (Statements (ECA)) then
- Last_Stm := ECA;
-
- -- Else check statement sequence and else part
-
- else
- Check_Statement_Sequence (Statements (ECA));
- Check_Statement_Sequence (Else_Statements (Last_Stm));
- return;
- end if;
- end;
- end if;
-
- -- If we fall through, issue appropriate message
-
- if Mode = 'F' then
-
- if not Raise_Exception_Call then
- Error_Msg_N
- ("?RETURN statement missing following this statement!",
- Last_Stm);
- Error_Msg_N
- ("\?Program_Error may be raised at run time",
- Last_Stm);
- end if;
-
- -- Note: we set Err even though we have not issued a warning
- -- because we still have a case of a missing return. This is
- -- an extremely marginal case, probably will never be noticed
- -- but we might as well get it right.
-
- Err := True;
-
- else
- Error_Msg_N
- ("implied return after this statement not allowed (No_Return)",
- Last_Stm);
- end if;
- end Check_Statement_Sequence;
-
- -- Start of processing for Check_Returns
-
- begin
- Err := False;
- Check_Statement_Sequence (Statements (HSS));
-
- if Present (Exception_Handlers (HSS)) then
- Handler := First_Non_Pragma (Exception_Handlers (HSS));
- while Present (Handler) loop
- Check_Statement_Sequence (Statements (Handler));
- Next_Non_Pragma (Handler);
- end loop;
- end if;
- end Check_Returns;
-
- ----------------------------
- -- Check_Subprogram_Order --
- ----------------------------
-
- procedure Check_Subprogram_Order (N : Node_Id) is
-
- function Subprogram_Name_Greater (S1, S2 : String) return Boolean;
- -- This is used to check if S1 > S2 in the sense required by this
- -- test, for example nameab < namec, but name2 < name10.
-
- function Subprogram_Name_Greater (S1, S2 : String) return Boolean is
- L1, L2 : Positive;
- N1, N2 : Natural;
-
- begin
- -- Remove trailing numeric parts
-
- L1 := S1'Last;
- while S1 (L1) in '0' .. '9' loop
- L1 := L1 - 1;
- end loop;
-
- L2 := S2'Last;
- while S2 (L2) in '0' .. '9' loop
- L2 := L2 - 1;
- end loop;
-
- -- If non-numeric parts non-equal, that's decisive
-
- if S1 (S1'First .. L1) < S2 (S2'First .. L2) then
- return False;
-
- elsif S1 (S1'First .. L1) > S2 (S2'First .. L2) then
- return True;
-
- -- If non-numeric parts equal, compare suffixed numeric parts. Note
- -- that a missing suffix is treated as numeric zero in this test.
-
- else
- N1 := 0;
- while L1 < S1'Last loop
- L1 := L1 + 1;
- N1 := N1 * 10 + Character'Pos (S1 (L1)) - Character'Pos ('0');
- end loop;
-
- N2 := 0;
- while L2 < S2'Last loop
- L2 := L2 + 1;
- N2 := N2 * 10 + Character'Pos (S2 (L2)) - Character'Pos ('0');
- end loop;
-
- return N1 > N2;
- end if;
- end Subprogram_Name_Greater;
-
- -- Start of processing for Check_Subprogram_Order
-
- begin
- -- Check body in alpha order if this is option
-
- if Style_Check_Subprogram_Order
- and then Nkind (N) = N_Subprogram_Body
- and then Comes_From_Source (N)
- and then In_Extended_Main_Source_Unit (N)
- then
- declare
- LSN : String_Ptr
- renames Scope_Stack.Table
- (Scope_Stack.Last).Last_Subprogram_Name;
-
- Body_Id : constant Entity_Id :=
- Defining_Entity (Specification (N));
-
- begin
- Get_Decoded_Name_String (Chars (Body_Id));
-
- if LSN /= null then
- if Subprogram_Name_Greater
- (LSN.all, Name_Buffer (1 .. Name_Len))
- then
- Style.Subprogram_Not_In_Alpha_Order (Body_Id);
- end if;
-
- Free (LSN);
- end if;
-
- LSN := new String'(Name_Buffer (1 .. Name_Len));
- end;
- end if;
- end Check_Subprogram_Order;
-
- ------------------------------
- -- Check_Subtype_Conformant --
- ------------------------------
-
- procedure Check_Subtype_Conformant
- (New_Id : Entity_Id;
- Old_Id : Entity_Id;
- Err_Loc : Node_Id := Empty)
- is
- Result : Boolean;
-
- begin
- Check_Conformance
- (New_Id, Old_Id, Subtype_Conformant, True, Result, Err_Loc);
- end Check_Subtype_Conformant;
-
- ---------------------------
- -- Check_Type_Conformant --
- ---------------------------
-
- procedure Check_Type_Conformant
- (New_Id : Entity_Id;
- Old_Id : Entity_Id;
- Err_Loc : Node_Id := Empty)
- is
- Result : Boolean;
-
- begin
- Check_Conformance
- (New_Id, Old_Id, Type_Conformant, True, Result, Err_Loc);
- end Check_Type_Conformant;
-
- ----------------------
- -- Conforming_Types --
- ----------------------
-
- function Conforming_Types
- (T1 : Entity_Id;
- T2 : Entity_Id;
- Ctype : Conformance_Type;
- Get_Inst : Boolean := False)
- return Boolean
- is
- Type_1 : Entity_Id := T1;
- Type_2 : Entity_Id := T2;
-
- function Base_Types_Match (T1, T2 : Entity_Id) return Boolean;
- -- If neither T1 nor T2 are generic actual types, then verify
- -- that the base types are equal. Otherwise T1 and T2 must be
- -- on the same subtype chain. The whole purpose of this procedure
- -- is to prevent spurious ambiguities in an instantiation that may
- -- arise if two distinct generic types are instantiated with the
- -- same actual.
-
- ----------------------
- -- Base_Types_Match --
- ----------------------
-
- function Base_Types_Match (T1, T2 : Entity_Id) return Boolean is
- begin
- if T1 = T2 then
- return True;
-
- elsif Base_Type (T1) = Base_Type (T2) then
-
- -- The following is too permissive. A more precise test must
- -- check that the generic actual is an ancestor subtype of the
- -- other ???.
-
- return not Is_Generic_Actual_Type (T1)
- or else not Is_Generic_Actual_Type (T2);
-
- else
- return False;
- end if;
- end Base_Types_Match;
-
- begin
- -- The context is an instance association for a formal
- -- access-to-subprogram type; the formal parameter types
- -- require mapping because they may denote other formal
- -- parameters of the generic unit.
-
- if Get_Inst then
- Type_1 := Get_Instance_Of (T1);
- Type_2 := Get_Instance_Of (T2);
- end if;
-
- -- First see if base types match
-
- if Base_Types_Match (Type_1, Type_2) then
- return Ctype <= Mode_Conformant
- or else Subtypes_Statically_Match (Type_1, Type_2);
-
- elsif Is_Incomplete_Or_Private_Type (Type_1)
- and then Present (Full_View (Type_1))
- and then Base_Types_Match (Full_View (Type_1), Type_2)
- then
- return Ctype <= Mode_Conformant
- or else Subtypes_Statically_Match (Full_View (Type_1), Type_2);
-
- elsif Ekind (Type_2) = E_Incomplete_Type
- and then Present (Full_View (Type_2))
- and then Base_Types_Match (Type_1, Full_View (Type_2))
- then
- return Ctype <= Mode_Conformant
- or else Subtypes_Statically_Match (Type_1, Full_View (Type_2));
- end if;
-
- -- Test anonymous access type case. For this case, static subtype
- -- matching is required for mode conformance (RM 6.3.1(15))
-
- if Ekind (Type_1) = E_Anonymous_Access_Type
- and then Ekind (Type_2) = E_Anonymous_Access_Type
- then
- declare
- Desig_1 : Entity_Id;
- Desig_2 : Entity_Id;
-
- begin
- Desig_1 := Directly_Designated_Type (Type_1);
-
- -- An access parameter can designate an incomplete type.
-
- if Ekind (Desig_1) = E_Incomplete_Type
- and then Present (Full_View (Desig_1))
- then
- Desig_1 := Full_View (Desig_1);
- end if;
-
- Desig_2 := Directly_Designated_Type (Type_2);
-
- if Ekind (Desig_2) = E_Incomplete_Type
- and then Present (Full_View (Desig_2))
- then
- Desig_2 := Full_View (Desig_2);
- end if;
-
- -- The context is an instance association for a formal
- -- access-to-subprogram type; formal access parameter
- -- designated types require mapping because they may
- -- denote other formal parameters of the generic unit.
-
- if Get_Inst then
- Desig_1 := Get_Instance_Of (Desig_1);
- Desig_2 := Get_Instance_Of (Desig_2);
- end if;
-
- -- It is possible for a Class_Wide_Type to be introduced for
- -- an incomplete type, in which case there is a separate class_
- -- wide type for the full view. The types conform if their
- -- Etypes conform, i.e. one may be the full view of the other.
- -- This can only happen in the context of an access parameter,
- -- other uses of an incomplete Class_Wide_Type are illegal.
-
- if Ekind (Desig_1) = E_Class_Wide_Type
- and then Ekind (Desig_2) = E_Class_Wide_Type
- then
- return
- Conforming_Types (Etype (Desig_1), Etype (Desig_2), Ctype);
- else
- return Base_Type (Desig_1) = Base_Type (Desig_2)
- and then (Ctype = Type_Conformant
- or else
- Subtypes_Statically_Match (Desig_1, Desig_2));
- end if;
- end;
-
- -- Otherwise definitely no match
-
- else
- return False;
- end if;
-
- end Conforming_Types;
-
- --------------------------
- -- Create_Extra_Formals --
- --------------------------
-
- procedure Create_Extra_Formals (E : Entity_Id) is
- Formal : Entity_Id;
- Last_Formal : Entity_Id;
- Last_Extra : Entity_Id;
- Formal_Type : Entity_Id;
- P_Formal : Entity_Id := Empty;
-
- function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id;
- -- Add an extra formal, associated with the current Formal. The
- -- extra formal is added to the list of extra formals, and also
- -- returned as the result. These formals are always of mode IN.
-
- function Add_Extra_Formal (Typ : Entity_Id) return Entity_Id is
- EF : constant Entity_Id :=
- Make_Defining_Identifier (Sloc (Formal),
- Chars => New_External_Name (Chars (Formal), 'F'));
-
- begin
- -- We never generate extra formals if expansion is not active
- -- because we don't need them unless we are generating code.
-
- if not Expander_Active then
- return Empty;
- end if;
-
- -- A little optimization. Never generate an extra formal for
- -- the _init operand of an initialization procedure, since it
- -- could never be used.
-
- if Chars (Formal) = Name_uInit then
- return Empty;
- end if;
-
- Set_Ekind (EF, E_In_Parameter);
- Set_Actual_Subtype (EF, Typ);
- Set_Etype (EF, Typ);
- Set_Scope (EF, Scope (Formal));
- Set_Mechanism (EF, Default_Mechanism);
- Set_Formal_Validity (EF);
-
- Set_Extra_Formal (Last_Extra, EF);
- Last_Extra := EF;
- return EF;
- end Add_Extra_Formal;
-
- -- Start of processing for Create_Extra_Formals
-
- begin
- -- If this is a derived subprogram then the subtypes of the
- -- parent subprogram's formal parameters will be used to
- -- to determine the need for extra formals.
-
- if Is_Overloadable (E) and then Present (Alias (E)) then
- P_Formal := First_Formal (Alias (E));
- end if;
-
- Last_Extra := Empty;
- Formal := First_Formal (E);
- while Present (Formal) loop
- Last_Extra := Formal;
- Next_Formal (Formal);
- end loop;
-
- -- If Extra_formals where already created, don't do it again
- -- This situation may arise for subprogram types created as part
- -- of dispatching calls (see Expand_Dispatch_Call)
-
- if Present (Last_Extra) and then
- Present (Extra_Formal (Last_Extra))
- then
- return;
- end if;
-
- Formal := First_Formal (E);
-
- while Present (Formal) loop
-
- -- Create extra formal for supporting the attribute 'Constrained.
- -- The case of a private type view without discriminants also
- -- requires the extra formal if the underlying type has defaulted
- -- discriminants.
-
- if Ekind (Formal) /= E_In_Parameter then
- if Present (P_Formal) then
- Formal_Type := Etype (P_Formal);
- else
- Formal_Type := Etype (Formal);
- end if;
-
- if not Has_Discriminants (Formal_Type)
- and then Ekind (Formal_Type) in Private_Kind
- and then Present (Underlying_Type (Formal_Type))
- then
- Formal_Type := Underlying_Type (Formal_Type);
- end if;
-
- if Has_Discriminants (Formal_Type)
- and then
- ((not Is_Constrained (Formal_Type)
- and then not Is_Indefinite_Subtype (Formal_Type))
- or else Present (Extra_Formal (Formal)))
- then
- Set_Extra_Constrained
- (Formal, Add_Extra_Formal (Standard_Boolean));
- end if;
- end if;
-
- -- Create extra formal for supporting accessibility checking
-
- -- This is suppressed if we specifically suppress accessibility
- -- checks for either the subprogram, or the package in which it
- -- resides. However, we do not suppress it simply if the scope
- -- has accessibility checks suppressed, since this could cause
- -- trouble when clients are compiled with a different suppression
- -- setting. The explicit checks are safe from this point of view.
-
- if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
- and then not
- (Suppress_Accessibility_Checks (E)
- or else
- Suppress_Accessibility_Checks (Scope (E)))
- and then
- (not Present (P_Formal)
- or else Present (Extra_Accessibility (P_Formal)))
- then
- -- Temporary kludge: for now we avoid creating the extra
- -- formal for access parameters of protected operations
- -- because of problem with the case of internal protected
- -- calls. ???
-
- if Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Definition
- and then Nkind (Parent (Parent (Parent (E)))) /= N_Protected_Body
- then
- Set_Extra_Accessibility
- (Formal, Add_Extra_Formal (Standard_Natural));
- end if;
- end if;
-
- if Present (P_Formal) then
- Next_Formal (P_Formal);
- end if;
-
- Last_Formal := Formal;
- Next_Formal (Formal);
- end loop;
- end Create_Extra_Formals;
-
- -----------------------------
- -- Enter_Overloaded_Entity --
- -----------------------------
-
- procedure Enter_Overloaded_Entity (S : Entity_Id) is
- E : Entity_Id := Current_Entity_In_Scope (S);
- C_E : Entity_Id := Current_Entity (S);
-
- begin
- if Present (E) then
- Set_Has_Homonym (E);
- Set_Has_Homonym (S);
- end if;
-
- Set_Is_Immediately_Visible (S);
- Set_Scope (S, Current_Scope);
-
- -- Chain new entity if front of homonym in current scope, so that
- -- homonyms are contiguous.
-
- if Present (E)
- and then E /= C_E
- then
- while Homonym (C_E) /= E loop
- C_E := Homonym (C_E);
- end loop;
-
- Set_Homonym (C_E, S);
-
- else
- E := C_E;
- Set_Current_Entity (S);
- end if;
-
- Set_Homonym (S, E);
-
- Append_Entity (S, Current_Scope);
- Set_Public_Status (S);
-
- if Debug_Flag_E then
- Write_Str ("New overloaded entity chain: ");
- Write_Name (Chars (S));
- E := S;
-
- while Present (E) loop
- Write_Str (" "); Write_Int (Int (E));
- E := Homonym (E);
- end loop;
-
- Write_Eol;
- end if;
-
- -- Generate warning for hiding
-
- if Warn_On_Hiding
- and then Comes_From_Source (S)
- and then In_Extended_Main_Source_Unit (S)
- then
- E := S;
- loop
- E := Homonym (E);
- exit when No (E);
-
- -- Warn unless genuine overloading
-
- if (not Is_Overloadable (E))
- or else Subtype_Conformant (E, S)
- then
- Error_Msg_Sloc := Sloc (E);
- Error_Msg_N ("declaration of & hides one#?", S);
- end if;
- end loop;
- end if;
- end Enter_Overloaded_Entity;
-
- -----------------------------
- -- Find_Corresponding_Spec --
- -----------------------------
-
- function Find_Corresponding_Spec (N : Node_Id) return Entity_Id is
- Spec : constant Node_Id := Specification (N);
- Designator : constant Entity_Id := Defining_Entity (Spec);
-
- E : Entity_Id;
-
- begin
- E := Current_Entity (Designator);
-
- while Present (E) loop
-
- -- We are looking for a matching spec. It must have the same scope,
- -- and the same name, and either be type conformant, or be the case
- -- of a library procedure spec and its body (which belong to one
- -- another regardless of whether they are type conformant or not).
-
- if Scope (E) = Current_Scope then
- if (Current_Scope = Standard_Standard
- or else (Ekind (E) = Ekind (Designator)
- and then
- Type_Conformant (E, Designator)))
- then
- -- Within an instantiation, we know that spec and body are
- -- subtype conformant, because they were subtype conformant
- -- in the generic. We choose the subtype-conformant entity
- -- here as well, to resolve spurious ambiguities in the
- -- instance that were not present in the generic (i.e. when
- -- two different types are given the same actual). If we are
- -- looking for a spec to match a body, full conformance is
- -- expected.
-
- if In_Instance then
- Set_Convention (Designator, Convention (E));
-
- if Nkind (N) = N_Subprogram_Body
- and then Present (Homonym (E))
- and then not Fully_Conformant (E, Designator)
- then
- goto Next_Entity;
-
- elsif not Subtype_Conformant (E, Designator) then
- goto Next_Entity;
- end if;
- end if;
-
- if not Has_Completion (E) then
-
- if Nkind (N) /= N_Subprogram_Body_Stub then
- Set_Corresponding_Spec (N, E);
- end if;
-
- Set_Has_Completion (E);
- return E;
-
- elsif Nkind (Parent (N)) = N_Subunit then
-
- -- If this is the proper body of a subunit, the completion
- -- flag is set when analyzing the stub.
-
- return E;
-
- -- If body already exists, this is an error unless the
- -- previous declaration is the implicit declaration of
- -- a derived subprogram, or this is a spurious overloading
- -- in an instance.
-
- elsif No (Alias (E))
- and then not Is_Intrinsic_Subprogram (E)
- and then not In_Instance
- then
- Error_Msg_Sloc := Sloc (E);
- Error_Msg_NE ("duplicate body for & declared#", N, E);
- end if;
-
- elsif Is_Child_Unit (E)
- and then
- Nkind (Unit_Declaration_Node (Designator)) = N_Subprogram_Body
- and then
- Nkind (Parent (Unit_Declaration_Node (Designator)))
- = N_Compilation_Unit
- then
-
- -- Child units cannot be overloaded, so a conformance mismatch
- -- between body and a previous spec is an error.
-
- Error_Msg_N
- ("body of child unit does not match previous declaration", N);
- end if;
- end if;
-
- <<Next_Entity>>
- E := Homonym (E);
- end loop;
-
- -- On exit, we know that no previous declaration of subprogram exists
-
- return Empty;
- end Find_Corresponding_Spec;
-
- ----------------------
- -- Fully_Conformant --
- ----------------------
-
- function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
- Result : Boolean;
-
- begin
- Check_Conformance (New_Id, Old_Id, Fully_Conformant, False, Result);
- return Result;
- end Fully_Conformant;
-
- ----------------------------------
- -- Fully_Conformant_Expressions --
- ----------------------------------
-
- function Fully_Conformant_Expressions
- (Given_E1 : Node_Id;
- Given_E2 : Node_Id)
- return Boolean
- is
- E1 : constant Node_Id := Original_Node (Given_E1);
- E2 : constant Node_Id := Original_Node (Given_E2);
- -- We always test conformance on original nodes, since it is possible
- -- for analysis and/or expansion to make things look as though they
- -- conform when they do not, e.g. by converting 1+2 into 3.
-
- function FCE (Given_E1, Given_E2 : Node_Id) return Boolean
- renames Fully_Conformant_Expressions;
-
- function FCL (L1, L2 : List_Id) return Boolean;
- -- Compare elements of two lists for conformance. Elements have to
- -- be conformant, and actuals inserted as default parameters do not
- -- match explicit actuals with the same value.
-
- function FCO (Op_Node, Call_Node : Node_Id) return Boolean;
- -- Compare an operator node with a function call.
-
- ---------
- -- FCL --
- ---------
-
- function FCL (L1, L2 : List_Id) return Boolean is
- N1, N2 : Node_Id;
-
- begin
- if L1 = No_List then
- N1 := Empty;
- else
- N1 := First (L1);
- end if;
-
- if L2 = No_List then
- N2 := Empty;
- else
- N2 := First (L2);
- end if;
-
- -- Compare two lists, skipping rewrite insertions (we want to
- -- compare the original trees, not the expanded versions!)
-
- loop
- if Is_Rewrite_Insertion (N1) then
- Next (N1);
- elsif Is_Rewrite_Insertion (N2) then
- Next (N2);
- elsif No (N1) then
- return No (N2);
- elsif No (N2) then
- return False;
- elsif not FCE (N1, N2) then
- return False;
- else
- Next (N1);
- Next (N2);
- end if;
- end loop;
- end FCL;
-
- ---------
- -- FCO --
- ---------
-
- function FCO (Op_Node, Call_Node : Node_Id) return Boolean is
- Actuals : constant List_Id := Parameter_Associations (Call_Node);
- Act : Node_Id;
-
- begin
- if No (Actuals)
- or else Entity (Op_Node) /= Entity (Name (Call_Node))
- then
- return False;
-
- else
- Act := First (Actuals);
-
- if Nkind (Op_Node) in N_Binary_Op then
-
- if not FCE (Left_Opnd (Op_Node), Act) then
- return False;
- end if;
-
- Next (Act);
- end if;
-
- return Present (Act)
- and then FCE (Right_Opnd (Op_Node), Act)
- and then No (Next (Act));
- end if;
- end FCO;
-
- -- Start of processing for Fully_Conformant_Expressions
-
- begin
- -- Non-conformant if paren count does not match. Note: if some idiot
- -- complains that we don't do this right for more than 3 levels of
- -- parentheses, they will be treated with the respect they deserve :-)
-
- if Paren_Count (E1) /= Paren_Count (E2) then
- return False;
-
- -- If same entities are referenced, then they are conformant
- -- even if they have different forms (RM 8.3.1(19-20)).
-
- elsif Is_Entity_Name (E1) and then Is_Entity_Name (E2) then
- if Present (Entity (E1)) then
- return Entity (E1) = Entity (E2)
- or else (Chars (Entity (E1)) = Chars (Entity (E2))
- and then Ekind (Entity (E1)) = E_Discriminant
- and then Ekind (Entity (E2)) = E_In_Parameter);
-
- elsif Nkind (E1) = N_Expanded_Name
- and then Nkind (E2) = N_Expanded_Name
- and then Nkind (Selector_Name (E1)) = N_Character_Literal
- and then Nkind (Selector_Name (E2)) = N_Character_Literal
- then
- return Chars (Selector_Name (E1)) = Chars (Selector_Name (E2));
-
- else
- -- Identifiers in component associations don't always have
- -- entities, but their names must conform.
-
- return Nkind (E1) = N_Identifier
- and then Nkind (E2) = N_Identifier
- and then Chars (E1) = Chars (E2);
- end if;
-
- elsif Nkind (E1) = N_Character_Literal
- and then Nkind (E2) = N_Expanded_Name
- then
- return Nkind (Selector_Name (E2)) = N_Character_Literal
- and then Chars (E1) = Chars (Selector_Name (E2));
-
- elsif Nkind (E2) = N_Character_Literal
- and then Nkind (E1) = N_Expanded_Name
- then
- return Nkind (Selector_Name (E1)) = N_Character_Literal
- and then Chars (E2) = Chars (Selector_Name (E1));
-
- elsif Nkind (E1) in N_Op
- and then Nkind (E2) = N_Function_Call
- then
- return FCO (E1, E2);
-
- elsif Nkind (E2) in N_Op
- and then Nkind (E1) = N_Function_Call
- then
- return FCO (E2, E1);
-
- -- Otherwise we must have the same syntactic entity
-
- elsif Nkind (E1) /= Nkind (E2) then
- return False;
-
- -- At this point, we specialize by node type
-
- else
- case Nkind (E1) is
-
- when N_Aggregate =>
- return
- FCL (Expressions (E1), Expressions (E2))
- and then FCL (Component_Associations (E1),
- Component_Associations (E2));
-
- when N_Allocator =>
- if Nkind (Expression (E1)) = N_Qualified_Expression
- or else
- Nkind (Expression (E2)) = N_Qualified_Expression
- then
- return FCE (Expression (E1), Expression (E2));
-
- -- Check that the subtype marks and any constraints
- -- are conformant
-
- else
- declare
- Indic1 : constant Node_Id := Expression (E1);
- Indic2 : constant Node_Id := Expression (E2);
- Elt1 : Node_Id;
- Elt2 : Node_Id;
-
- begin
- if Nkind (Indic1) /= N_Subtype_Indication then
- return
- Nkind (Indic2) /= N_Subtype_Indication
- and then Entity (Indic1) = Entity (Indic2);
-
- elsif Nkind (Indic2) /= N_Subtype_Indication then
- return
- Nkind (Indic1) /= N_Subtype_Indication
- and then Entity (Indic1) = Entity (Indic2);
-
- else
- if Entity (Subtype_Mark (Indic1)) /=
- Entity (Subtype_Mark (Indic2))
- then
- return False;
- end if;
-
- Elt1 := First (Constraints (Constraint (Indic1)));
- Elt2 := First (Constraints (Constraint (Indic2)));
-
- while Present (Elt1) and then Present (Elt2) loop
- if not FCE (Elt1, Elt2) then
- return False;
- end if;
-
- Next (Elt1);
- Next (Elt2);
- end loop;
-
- return True;
- end if;
- end;
- end if;
-
- when N_Attribute_Reference =>
- return
- Attribute_Name (E1) = Attribute_Name (E2)
- and then FCL (Expressions (E1), Expressions (E2));
-
- when N_Binary_Op =>
- return
- Entity (E1) = Entity (E2)
- and then FCE (Left_Opnd (E1), Left_Opnd (E2))
- and then FCE (Right_Opnd (E1), Right_Opnd (E2));
-
- when N_And_Then | N_Or_Else | N_In | N_Not_In =>
- return
- FCE (Left_Opnd (E1), Left_Opnd (E2))
- and then
- FCE (Right_Opnd (E1), Right_Opnd (E2));
-
- when N_Character_Literal =>
- return
- Char_Literal_Value (E1) = Char_Literal_Value (E2);
-
- when N_Component_Association =>
- return
- FCL (Choices (E1), Choices (E2))
- and then FCE (Expression (E1), Expression (E2));
-
- when N_Conditional_Expression =>
- return
- FCL (Expressions (E1), Expressions (E2));
-
- when N_Explicit_Dereference =>
- return
- FCE (Prefix (E1), Prefix (E2));
-
- when N_Extension_Aggregate =>
- return
- FCL (Expressions (E1), Expressions (E2))
- and then Null_Record_Present (E1) =
- Null_Record_Present (E2)
- and then FCL (Component_Associations (E1),
- Component_Associations (E2));
-
- when N_Function_Call =>
- return
- FCE (Name (E1), Name (E2))
- and then FCL (Parameter_Associations (E1),
- Parameter_Associations (E2));
-
- when N_Indexed_Component =>
- return
- FCE (Prefix (E1), Prefix (E2))
- and then FCL (Expressions (E1), Expressions (E2));
-
- when N_Integer_Literal =>
- return (Intval (E1) = Intval (E2));
-
- when N_Null =>
- return True;
-
- when N_Operator_Symbol =>
- return
- Chars (E1) = Chars (E2);
-
- when N_Others_Choice =>
- return True;
-
- when N_Parameter_Association =>
- return
-
- Chars (Selector_Name (E1)) = Chars (Selector_Name (E2))
- and then FCE (Explicit_Actual_Parameter (E1),
- Explicit_Actual_Parameter (E2));
-
- when N_Qualified_Expression =>
- return
- FCE (Subtype_Mark (E1), Subtype_Mark (E2))
- and then FCE (Expression (E1), Expression (E2));
-
- when N_Range =>
- return
- FCE (Low_Bound (E1), Low_Bound (E2))
- and then FCE (High_Bound (E1), High_Bound (E2));
-
- when N_Real_Literal =>
- return (Realval (E1) = Realval (E2));
-
- when N_Selected_Component =>
- return
- FCE (Prefix (E1), Prefix (E2))
- and then FCE (Selector_Name (E1), Selector_Name (E2));
-
- when N_Slice =>
- return
- FCE (Prefix (E1), Prefix (E2))
- and then FCE (Discrete_Range (E1), Discrete_Range (E2));
-
- when N_String_Literal =>
- declare
- S1 : constant String_Id := Strval (E1);
- S2 : constant String_Id := Strval (E2);
- L1 : constant Nat := String_Length (S1);
- L2 : constant Nat := String_Length (S2);
-
- begin
- if L1 /= L2 then
- return False;
-
- else
- for J in 1 .. L1 loop
- if Get_String_Char (S1, J) /=
- Get_String_Char (S2, J)
- then
- return False;
- end if;
- end loop;
-
- return True;
- end if;
- end;
-
- when N_Type_Conversion =>
- return
- FCE (Subtype_Mark (E1), Subtype_Mark (E2))
- and then FCE (Expression (E1), Expression (E2));
-
- when N_Unary_Op =>
- return
- Entity (E1) = Entity (E2)
- and then FCE (Right_Opnd (E1), Right_Opnd (E2));
-
- when N_Unchecked_Type_Conversion =>
- return
- FCE (Subtype_Mark (E1), Subtype_Mark (E2))
- and then FCE (Expression (E1), Expression (E2));
-
- -- All other node types cannot appear in this context. Strictly
- -- we should raise a fatal internal error. Instead we just ignore
- -- the nodes. This means that if anyone makes a mistake in the
- -- expander and mucks an expression tree irretrievably, the
- -- result will be a failure to detect a (probably very obscure)
- -- case of non-conformance, which is better than bombing on some
- -- case where two expressions do in fact conform.
-
- when others =>
- return True;
-
- end case;
- end if;
- end Fully_Conformant_Expressions;
-
- --------------------
- -- Install_Entity --
- --------------------
-
- procedure Install_Entity (E : Entity_Id) is
- Prev : constant Entity_Id := Current_Entity (E);
-
- begin
- Set_Is_Immediately_Visible (E);
- Set_Current_Entity (E);
- Set_Homonym (E, Prev);
- end Install_Entity;
-
- ---------------------
- -- Install_Formals --
- ---------------------
-
- procedure Install_Formals (Id : Entity_Id) is
- F : Entity_Id;
-
- begin
- F := First_Formal (Id);
-
- while Present (F) loop
- Install_Entity (F);
- Next_Formal (F);
- end loop;
- end Install_Formals;
-
- ---------------------------------
- -- Is_Non_Overriding_Operation --
- ---------------------------------
-
- function Is_Non_Overriding_Operation
- (Prev_E : Entity_Id;
- New_E : Entity_Id)
- return Boolean
- is
- Formal : Entity_Id;
- F_Typ : Entity_Id;
- G_Typ : Entity_Id := Empty;
-
- function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id;
- -- If F_Type is a derived type associated with a generic actual
- -- subtype, then return its Generic_Parent_Type attribute, else
- -- return Empty.
-
- function Types_Correspond
- (P_Type : Entity_Id;
- N_Type : Entity_Id)
- return Boolean;
- -- Returns true if and only if the types (or designated types
- -- in the case of anonymous access types) are the same or N_Type
- -- is derived directly or indirectly from P_Type.
-
- -----------------------------
- -- Get_Generic_Parent_Type --
- -----------------------------
-
- function Get_Generic_Parent_Type (F_Typ : Entity_Id) return Entity_Id is
- G_Typ : Entity_Id;
- Indic : Node_Id;
-
- begin
- if Is_Derived_Type (F_Typ)
- and then Nkind (Parent (F_Typ)) = N_Full_Type_Declaration
- then
- -- The tree must be traversed to determine the parent
- -- subtype in the generic unit, which unfortunately isn't
- -- always available via semantic attributes. ???
- -- (Note: The use of Original_Node is needed for cases
- -- where a full derived type has been rewritten.)
-
- Indic := Subtype_Indication
- (Type_Definition (Original_Node (Parent (F_Typ))));
-
- if Nkind (Indic) = N_Subtype_Indication then
- G_Typ := Entity (Subtype_Mark (Indic));
- else
- G_Typ := Entity (Indic);
- end if;
-
- if Nkind (Parent (G_Typ)) = N_Subtype_Declaration
- and then Present (Generic_Parent_Type (Parent (G_Typ)))
- then
- return Generic_Parent_Type (Parent (G_Typ));
- end if;
- end if;
-
- return Empty;
- end Get_Generic_Parent_Type;
-
- ----------------------
- -- Types_Correspond --
- ----------------------
-
- function Types_Correspond
- (P_Type : Entity_Id;
- N_Type : Entity_Id)
- return Boolean
- is
- Prev_Type : Entity_Id := Base_Type (P_Type);
- New_Type : Entity_Id := Base_Type (N_Type);
-
- begin
- if Ekind (Prev_Type) = E_Anonymous_Access_Type then
- Prev_Type := Designated_Type (Prev_Type);
- end if;
-
- if Ekind (New_Type) = E_Anonymous_Access_Type then
- New_Type := Designated_Type (New_Type);
- end if;
-
- if Prev_Type = New_Type then
- return True;
-
- elsif not Is_Class_Wide_Type (New_Type) then
- while Etype (New_Type) /= New_Type loop
- New_Type := Etype (New_Type);
- if New_Type = Prev_Type then
- return True;
- end if;
- end loop;
- end if;
- return False;
- end Types_Correspond;
-
- -- Start of processing for Is_Non_Overriding_Operation
-
- begin
- -- In the case where both operations are implicit derived
- -- subprograms then neither overrides the other. This can
- -- only occur in certain obscure cases (e.g., derivation
- -- from homographs created in a generic instantiation).
-
- if Present (Alias (Prev_E)) and then Present (Alias (New_E)) then
- return True;
-
- elsif Ekind (Current_Scope) = E_Package
- and then Is_Generic_Instance (Current_Scope)
- and then In_Private_Part (Current_Scope)
- and then Comes_From_Source (New_E)
- then
- -- We examine the formals and result subtype of the inherited
- -- operation, to determine whether their type is derived from
- -- (the instance of) a generic type.
-
- Formal := First_Formal (Prev_E);
-
- while Present (Formal) loop
- F_Typ := Base_Type (Etype (Formal));
-
- if Ekind (F_Typ) = E_Anonymous_Access_Type then
- F_Typ := Designated_Type (F_Typ);
- end if;
-
- G_Typ := Get_Generic_Parent_Type (F_Typ);
-
- Next_Formal (Formal);
- end loop;
-
- if not Present (G_Typ) and then Ekind (Prev_E) = E_Function then
- G_Typ := Get_Generic_Parent_Type (Base_Type (Etype (Prev_E)));
- end if;
-
- if No (G_Typ) then
- return False;
- end if;
-
- -- If the generic type is a private type, then the original
- -- operation was not overriding in the generic, because there was
- -- no primitive operation to override.
-
- if Nkind (Parent (G_Typ)) = N_Formal_Type_Declaration
- and then Nkind (Formal_Type_Definition (Parent (G_Typ))) =
- N_Formal_Private_Type_Definition
- then
- return True;
-
- -- The generic parent type is the ancestor of a formal derived
- -- type declaration. We need to check whether it has a primitive
- -- operation that should be overridden by New_E in the generic.
-
- else
- declare
- P_Formal : Entity_Id;
- N_Formal : Entity_Id;
- P_Typ : Entity_Id;
- N_Typ : Entity_Id;
- P_Prim : Entity_Id;
- Prim_Elt : Elmt_Id := First_Elmt (Primitive_Operations (G_Typ));
-
- begin
- while Present (Prim_Elt) loop
- P_Prim := Node (Prim_Elt);
- if Chars (P_Prim) = Chars (New_E)
- and then Ekind (P_Prim) = Ekind (New_E)
- then
- P_Formal := First_Formal (P_Prim);
- N_Formal := First_Formal (New_E);
- while Present (P_Formal) and then Present (N_Formal) loop
- P_Typ := Etype (P_Formal);
- N_Typ := Etype (N_Formal);
-
- if not Types_Correspond (P_Typ, N_Typ) then
- exit;
- end if;
-
- Next_Entity (P_Formal);
- Next_Entity (N_Formal);
- end loop;
-
- -- Found a matching primitive operation belonging to
- -- the formal ancestor type, so the new subprogram
- -- is overriding.
-
- if not Present (P_Formal)
- and then not Present (N_Formal)
- and then (Ekind (New_E) /= E_Function
- or else
- Types_Correspond
- (Etype (P_Prim), Etype (New_E)))
- then
- return False;
- end if;
- end if;
-
- Next_Elmt (Prim_Elt);
- end loop;
-
- -- If no match found, then the new subprogram does
- -- not override in the generic (nor in the instance).
-
- return True;
- end;
- end if;
- else
- return False;
- end if;
- end Is_Non_Overriding_Operation;
-
- ------------------------------
- -- Make_Inequality_Operator --
- ------------------------------
-
- -- S is the defining identifier of an equality operator. We build a
- -- subprogram declaration with the right signature. This operation is
- -- intrinsic, because it is always expanded as the negation of the
- -- call to the equality function.
-
- procedure Make_Inequality_Operator (S : Entity_Id) is
- Loc : constant Source_Ptr := Sloc (S);
- Decl : Node_Id;
- Formals : List_Id;
- Op_Name : Entity_Id;
-
- A : Entity_Id;
- B : Entity_Id;
-
- begin
- -- Check that equality was properly defined.
-
- if No (Next_Formal (First_Formal (S))) then
- return;
- end if;
-
- A := Make_Defining_Identifier (Loc, Chars (First_Formal (S)));
- B := Make_Defining_Identifier (Loc,
- Chars (Next_Formal (First_Formal (S))));
-
- Op_Name := Make_Defining_Operator_Symbol (Loc, Name_Op_Ne);
-
- Formals := New_List (
- Make_Parameter_Specification (Loc,
- Defining_Identifier => A,
- Parameter_Type =>
- New_Reference_To (Etype (First_Formal (S)), Loc)),
-
- Make_Parameter_Specification (Loc,
- Defining_Identifier => B,
- Parameter_Type =>
- New_Reference_To (Etype (Next_Formal (First_Formal (S))), Loc)));
-
- Decl :=
- Make_Subprogram_Declaration (Loc,
- Specification =>
- Make_Function_Specification (Loc,
- Defining_Unit_Name => Op_Name,
- Parameter_Specifications => Formals,
- Subtype_Mark => New_Reference_To (Standard_Boolean, Loc)));
-
- -- Insert inequality right after equality if it is explicit or after
- -- the derived type when implicit. These entities are created only
- -- for visibility purposes, and eventually replaced in the course of
- -- expansion, so they do not need to be attached to the tree and seen
- -- by the back-end. Keeping them internal also avoids spurious freezing
- -- problems. The parent field is set simply to make analysis safe.
-
- if No (Alias (S)) then
- Set_Parent (Decl, Parent (Unit_Declaration_Node (S)));
- else
- Set_Parent (Decl, Parent (Parent (Etype (First_Formal (S)))));
- end if;
-
- Mark_Rewrite_Insertion (Decl);
- Set_Is_Intrinsic_Subprogram (Op_Name);
- Analyze (Decl);
- Set_Has_Completion (Op_Name);
- Set_Corresponding_Equality (Op_Name, S);
- Set_Is_Abstract (Op_Name, Is_Abstract (S));
-
- end Make_Inequality_Operator;
-
- ----------------------
- -- May_Need_Actuals --
- ----------------------
-
- procedure May_Need_Actuals (Fun : Entity_Id) is
- F : Entity_Id;
- B : Boolean;
-
- begin
- F := First_Formal (Fun);
- B := True;
-
- while Present (F) loop
- if No (Default_Value (F)) then
- B := False;
- exit;
- end if;
-
- Next_Formal (F);
- end loop;
-
- Set_Needs_No_Actuals (Fun, B);
- end May_Need_Actuals;
-
- ---------------------
- -- Mode_Conformant --
- ---------------------
-
- function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
- Result : Boolean;
-
- begin
- Check_Conformance (New_Id, Old_Id, Mode_Conformant, False, Result);
- return Result;
- end Mode_Conformant;
-
- ---------------------------
- -- New_Overloaded_Entity --
- ---------------------------
-
- procedure New_Overloaded_Entity
- (S : Entity_Id;
- Derived_Type : Entity_Id := Empty)
- is
- E : Entity_Id := Current_Entity_In_Scope (S);
- Prev_Vis : Entity_Id := Empty;
-
- function Is_Private_Declaration (E : Entity_Id) return Boolean;
- -- Check that E is declared in the private part of the current package,
- -- or in the package body, where it may hide a previous declaration.
- -- We can' use In_Private_Part by itself because this flag is also
- -- set when freezing entities, so we must examine the place of the
- -- declaration in the tree, and recognize wrapper packages as well.
-
- procedure Maybe_Primitive_Operation (Overriding : Boolean := False);
- -- If the subprogram being analyzed is a primitive operation of
- -- the type of one of its formals, set the corresponding flag.
-
- ----------------------------
- -- Is_Private_Declaration --
- ----------------------------
-
- function Is_Private_Declaration (E : Entity_Id) return Boolean is
- Priv_Decls : List_Id;
- Decl : constant Node_Id := Unit_Declaration_Node (E);
-
- begin
- if Is_Package (Current_Scope)
- and then In_Private_Part (Current_Scope)
- then
- Priv_Decls :=
- Private_Declarations (
- Specification (Unit_Declaration_Node (Current_Scope)));
-
- return In_Package_Body (Current_Scope)
- or else List_Containing (Decl) = Priv_Decls
- or else (Nkind (Parent (Decl)) = N_Package_Specification
- and then not Is_Compilation_Unit (
- Defining_Entity (Parent (Decl)))
- and then List_Containing (Parent (Parent (Decl)))
- = Priv_Decls);
- else
- return False;
- end if;
- end Is_Private_Declaration;
-
- -------------------------------
- -- Maybe_Primitive_Operation --
- -------------------------------
-
- procedure Maybe_Primitive_Operation (Overriding : Boolean := False) is
- Formal : Entity_Id;
- F_Typ : Entity_Id;
-
- function Visible_Part_Type (T : Entity_Id) return Boolean;
- -- Returns true if T is declared in the visible part of
- -- the current package scope; otherwise returns false.
- -- Assumes that T is declared in a package.
-
- procedure Check_Private_Overriding (T : Entity_Id);
- -- Checks that if a primitive abstract subprogram of a visible
- -- abstract type is declared in a private part, then it must
- -- override an abstract subprogram declared in the visible part.
- -- Also checks that if a primitive function with a controlling
- -- result is declared in a private part, then it must override
- -- a function declared in the visible part.
-
- ------------------------------
- -- Check_Private_Overriding --
- ------------------------------
-
- procedure Check_Private_Overriding (T : Entity_Id) is
- begin
- if Ekind (Current_Scope) = E_Package
- and then In_Private_Part (Current_Scope)
- and then Visible_Part_Type (T)
- and then not In_Instance
- then
- if Is_Abstract (T)
- and then Is_Abstract (S)
- and then (not Overriding or else not Is_Abstract (E))
- then
- Error_Msg_N ("abstract subprograms must be visible "
- & "('R'M 3.9.3(10))!", S);
-
- elsif Ekind (S) = E_Function
- and then Is_Tagged_Type (T)
- and then T = Base_Type (Etype (S))
- and then not Overriding
- then
- Error_Msg_N
- ("private function with tagged result must"
- & " override visible-part function", S);
- Error_Msg_N
- ("\move subprogram to the visible part"
- & " ('R'M 3.9.3(10))", S);
- end if;
- end if;
- end Check_Private_Overriding;
-
- -----------------------
- -- Visible_Part_Type --
- -----------------------
-
- function Visible_Part_Type (T : Entity_Id) return Boolean is
- P : Node_Id := Unit_Declaration_Node (Scope (T));
- N : Node_Id := First (Visible_Declarations (Specification (P)));
-
- begin
- -- If the entity is a private type, then it must be
- -- declared in a visible part.
-
- if Ekind (T) in Private_Kind then
- return True;
- end if;
-
- -- Otherwise, we traverse the visible part looking for its
- -- corresponding declaration. We cannot use the declaration
- -- node directly because in the private part the entity of a
- -- private type is the one in the full view, which does not
- -- indicate that it is the completion of something visible.
-
- while Present (N) loop
- if Nkind (N) = N_Full_Type_Declaration
- and then Present (Defining_Identifier (N))
- and then T = Defining_Identifier (N)
- then
- return True;
-
- elsif (Nkind (N) = N_Private_Type_Declaration
- or else
- Nkind (N) = N_Private_Extension_Declaration)
- and then Present (Defining_Identifier (N))
- and then T = Full_View (Defining_Identifier (N))
- then
- return True;
- end if;
-
- Next (N);
- end loop;
-
- return False;
- end Visible_Part_Type;
-
- -- Start of processing for Maybe_Primitive_Operation
-
- begin
- if not Comes_From_Source (S) then
- null;
-
- elsif (Ekind (Current_Scope) = E_Package
- and then not In_Package_Body (Current_Scope))
- or else Overriding
- then
-
- if Ekind (S) = E_Function
- and then Scope (Base_Type (Etype (S))) = Current_Scope
- then
- Set_Has_Primitive_Operations (Base_Type (Etype (S)));
- Check_Private_Overriding (Base_Type (Etype (S)));
- end if;
-
- Formal := First_Formal (S);
-
- while Present (Formal) loop
- if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
- F_Typ := Designated_Type (Etype (Formal));
- else
- F_Typ := Etype (Formal);
- end if;
-
- if Scope (Base_Type (F_Typ)) = Current_Scope then
- Set_Has_Primitive_Operations (Base_Type (F_Typ));
- Check_Private_Overriding (Base_Type (F_Typ));
- end if;
-
- Next_Formal (Formal);
- end loop;
-
- end if;
- end Maybe_Primitive_Operation;
-
- -- Start of processing for New_Overloaded_Entity
-
- begin
- if No (E) then
- Enter_Overloaded_Entity (S);
- Check_Dispatching_Operation (S, Empty);
- Maybe_Primitive_Operation;
-
- elsif not Is_Overloadable (E) then
-
- -- Check for spurious conflict produced by a subprogram that has the
- -- same name as that of the enclosing generic package. The conflict
- -- occurs within an instance, between the subprogram and the renaming
- -- declaration for the package. After the subprogram, the package
- -- renaming declaration becomes hidden.
-
- if Ekind (E) = E_Package
- and then Present (Renamed_Object (E))
- and then Renamed_Object (E) = Current_Scope
- and then Nkind (Parent (Renamed_Object (E))) =
- N_Package_Specification
- and then Present (Generic_Parent (Parent (Renamed_Object (E))))
- then
- Set_Is_Hidden (E);
- Set_Is_Immediately_Visible (E, False);
- Enter_Overloaded_Entity (S);
- Set_Homonym (S, Homonym (E));
- Check_Dispatching_Operation (S, Empty);
-
- -- If the subprogram is implicit it is hidden by the previous
- -- declaration. However if it is dispatching, it must appear in
- -- the dispatch table anyway, because it can be dispatched to
- -- even if it cannot be called directly.
-
- elsif Present (Alias (S))
- and then not Comes_From_Source (S)
- then
- Set_Scope (S, Current_Scope);
-
- if Is_Dispatching_Operation (Alias (S)) then
- Check_Dispatching_Operation (S, Empty);
- end if;
-
- return;
-
- else
- Error_Msg_Sloc := Sloc (E);
- Error_Msg_N ("& conflicts with declaration#", S);
-
- -- Useful additional warning.
-
- if Is_Generic_Unit (E) then
- Error_Msg_N ("\previous generic unit cannot be overloaded", S);
- end if;
-
- return;
- end if;
-
- else
- -- E exists and is overloadable. Determine whether S is the body
- -- of E, a new overloaded entity with a different signature, or
- -- an error altogether.
-
- while Present (E) loop
- if Scope (E) /= Current_Scope then
- null;
-
- elsif Type_Conformant (E, S) then
-
- -- If the old and new entities have the same profile and
- -- one is not the body of the other, then this is an error,
- -- unless one of them is implicitly declared.
-
- -- There are some cases when both can be implicit, for example
- -- when both a literal and a function that overrides it are
- -- inherited in a derivation, or when an inhertited operation
- -- of a tagged full type overrides the ineherited operation of
- -- a private extension. Ada 83 had a special rule for the
- -- the literal case. In Ada95, the later implicit operation
- -- hides the former, and the literal is always the former.
- -- In the odd case where both are derived operations declared
- -- at the same point, both operations should be declared,
- -- and in that case we bypass the following test and proceed
- -- to the next part (this can only occur for certain obscure
- -- cases involving homographs in instances and can't occur for
- -- dispatching operations ???). Note that the following
- -- condition is less than clear. For example, it's not at
- -- all clear why there's a test for E_Entry here. ???
-
- if Present (Alias (S))
- and then (No (Alias (E))
- or else Comes_From_Source (E)
- or else Is_Dispatching_Operation (E))
- and then
- (Ekind (E) = E_Entry
- or else Ekind (E) /= E_Enumeration_Literal)
- then
- -- When an derived operation is overloaded it may be due
- -- to the fact that the full view of a private extension
- -- re-inherits. It has to be dealt with.
-
- if Is_Package (Current_Scope)
- and then In_Private_Part (Current_Scope)
- then
- Check_Operation_From_Private_View (S, E);
- end if;
-
- -- In any case the implicit operation remains hidden by
- -- the existing declaration.
-
- return;
-
- -- Within an instance, the renaming declarations for
- -- actual subprograms may become ambiguous, but they do
- -- not hide each other.
-
- elsif Ekind (E) /= E_Entry
- and then not Comes_From_Source (E)
- and then not Is_Generic_Instance (E)
- and then (Present (Alias (E))
- or else Is_Intrinsic_Subprogram (E))
- and then (not In_Instance
- or else No (Parent (E))
- or else Nkind (Unit_Declaration_Node (E)) /=
- N_Subprogram_Renaming_Declaration)
- then
- -- A subprogram child unit is not allowed to override
- -- an inherited subprogram (10.1.1(20)).
-
- if Is_Child_Unit (S) then
- Error_Msg_N
- ("child unit overrides inherited subprogram in parent",
- S);
- return;
- end if;
-
- if Is_Non_Overriding_Operation (E, S) then
- Enter_Overloaded_Entity (S);
- if not Present (Derived_Type)
- or else Is_Tagged_Type (Derived_Type)
- then
- Check_Dispatching_Operation (S, Empty);
- end if;
-
- return;
- end if;
-
- -- E is a derived operation or an internal operator which
- -- is being overridden. Remove E from further visibility.
- -- Furthermore, if E is a dispatching operation, it must be
- -- replaced in the list of primitive operations of its type
- -- (see Override_Dispatching_Operation).
-
- declare
- Prev : Entity_Id;
-
- begin
- Prev := First_Entity (Current_Scope);
-
- while Present (Prev)
- and then Next_Entity (Prev) /= E
- loop
- Next_Entity (Prev);
- end loop;
-
- -- It is possible for E to be in the current scope and
- -- yet not in the entity chain. This can only occur in a
- -- generic context where E is an implicit concatenation
- -- in the formal part, because in a generic body the
- -- entity chain starts with the formals.
-
- pragma Assert
- (Present (Prev) or else Chars (E) = Name_Op_Concat);
-
- -- E must be removed both from the entity_list of the
- -- current scope, and from the visibility chain
-
- if Debug_Flag_E then
- Write_Str ("Override implicit operation ");
- Write_Int (Int (E));
- Write_Eol;
- end if;
-
- -- If E is a predefined concatenation, it stands for four
- -- different operations. As a result, a single explicit
- -- declaration does not hide it. In a possible ambiguous
- -- situation, Disambiguate chooses the user-defined op,
- -- so it is correct to retain the previous internal one.
-
- if Chars (E) /= Name_Op_Concat
- or else Ekind (E) /= E_Operator
- then
- -- For nondispatching derived operations that are
- -- overridden by a subprogram declared in the private
- -- part of a package, we retain the derived subprogram
- -- but mark it as not immediately visible. If the
- -- derived operation was declared in the visible part
- -- then this ensures that it will still be visible
- -- outside the package with the proper signature
- -- (calls from outside must also be directed to this
- -- version rather than the overriding one, unlike the
- -- dispatching case). Calls from inside the package
- -- will still resolve to the overriding subprogram
- -- since the derived one is marked as not visible
- -- within the package.
-
- -- If the private operation is dispatching, we achieve
- -- the overriding by keeping the implicit operation
- -- but setting its alias to be the overring one. In
- -- this fashion the proper body is executed in all
- -- cases, but the original signature is used outside
- -- of the package.
-
- -- If the overriding is not in the private part, we
- -- remove the implicit operation altogether.
-
- if Is_Private_Declaration (S) then
-
- if not Is_Dispatching_Operation (E) then
- Set_Is_Immediately_Visible (E, False);
- else
-
- -- work done in Override_Dispatching_Operation.
-
- null;
- end if;
- else
-
- -- Find predecessor of E in Homonym chain.
-
- if E = Current_Entity (E) then
- Prev_Vis := Empty;
- else
- Prev_Vis := Current_Entity (E);
- while Homonym (Prev_Vis) /= E loop
- Prev_Vis := Homonym (Prev_Vis);
- end loop;
- end if;
-
- if Prev_Vis /= Empty then
-
- -- Skip E in the visibility chain
-
- Set_Homonym (Prev_Vis, Homonym (E));
-
- else
- Set_Name_Entity_Id (Chars (E), Homonym (E));
- end if;
-
- Set_Next_Entity (Prev, Next_Entity (E));
-
- if No (Next_Entity (Prev)) then
- Set_Last_Entity (Current_Scope, Prev);
- end if;
-
- end if;
- end if;
-
- Enter_Overloaded_Entity (S);
-
- if Is_Dispatching_Operation (E) then
- -- An overriding dispatching subprogram inherits
- -- the convention of the overridden subprogram
- -- (by AI-117).
-
- Set_Convention (S, Convention (E));
-
- Check_Dispatching_Operation (S, E);
- else
- Check_Dispatching_Operation (S, Empty);
- end if;
-
- Maybe_Primitive_Operation (Overriding => True);
- goto Check_Inequality;
- end;
-
- -- Apparent redeclarations in instances can occur when two
- -- formal types get the same actual type. The subprograms in
- -- in the instance are legal, even if not callable from the
- -- outside. Calls from within are disambiguated elsewhere.
- -- For dispatching operations in the visible part, the usual
- -- rules apply, and operations with the same profile are not
- -- legal (B830001).
-
- elsif (In_Instance_Visible_Part
- and then not Is_Dispatching_Operation (E))
- or else In_Instance_Not_Visible
- then
- null;
-
- -- Here we have a real error (identical profile)
-
- else
- Error_Msg_Sloc := Sloc (E);
-
- -- Avoid cascaded errors if the entity appears in
- -- subsequent calls.
-
- Set_Scope (S, Current_Scope);
-
- Error_Msg_N ("& conflicts with declaration#", S);
-
- if Is_Generic_Instance (S)
- and then not Has_Completion (E)
- then
- Error_Msg_N
- ("\instantiation cannot provide body for it", S);
- end if;
-
- return;
- end if;
-
- else
- null;
- end if;
-
- Prev_Vis := E;
- E := Homonym (E);
- end loop;
-
- -- On exit, we know that S is a new entity
-
- Enter_Overloaded_Entity (S);
- Maybe_Primitive_Operation;
-
- -- If S is a derived operation for an untagged type then
- -- by definition it's not a dispatching operation (even
- -- if the parent operation was dispatching), so we don't
- -- call Check_Dispatching_Operation in that case.
-
- if not Present (Derived_Type)
- or else Is_Tagged_Type (Derived_Type)
- then
- Check_Dispatching_Operation (S, Empty);
- end if;
- end if;
-
- -- If this is a user-defined equality operator that is not
- -- a derived subprogram, create the corresponding inequality.
- -- If the operation is dispatching, the expansion is done
- -- elsewhere, and we do not create an explicit inequality
- -- operation.
-
- <<Check_Inequality>>
- if Chars (S) = Name_Op_Eq
- and then Etype (S) = Standard_Boolean
- and then Present (Parent (S))
- and then not Is_Dispatching_Operation (S)
- then
- Make_Inequality_Operator (S);
- end if;
-
- end New_Overloaded_Entity;
-
- ---------------------
- -- Process_Formals --
- ---------------------
-
- procedure Process_Formals
- (S : Entity_Id;
- T : List_Id;
- Related_Nod : Node_Id)
- is
- Param_Spec : Node_Id;
- Formal : Entity_Id;
- Formal_Type : Entity_Id;
- Default : Node_Id;
- Ptype : Entity_Id;
-
- begin
- -- In order to prevent premature use of the formals in the same formal
- -- part, the Ekind is left undefined until all default expressions are
- -- analyzed. The Ekind is established in a separate loop at the end.
-
- Param_Spec := First (T);
-
- while Present (Param_Spec) loop
-
- Formal := Defining_Identifier (Param_Spec);
- Enter_Name (Formal);
-
- -- Case of ordinary parameters
-
- if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
- Find_Type (Parameter_Type (Param_Spec));
- Ptype := Parameter_Type (Param_Spec);
-
- if Ptype = Error then
- goto Continue;
- end if;
-
- Formal_Type := Entity (Ptype);
-
- if Ekind (Formal_Type) = E_Incomplete_Type
- or else (Is_Class_Wide_Type (Formal_Type)
- and then Ekind (Root_Type (Formal_Type)) =
- E_Incomplete_Type)
- then
- if Nkind (Parent (T)) /= N_Access_Function_Definition
- and then Nkind (Parent (T)) /= N_Access_Procedure_Definition
- then
- Error_Msg_N ("invalid use of incomplete type", Param_Spec);
- end if;
-
- elsif Ekind (Formal_Type) = E_Void then
- Error_Msg_NE ("premature use of&",
- Parameter_Type (Param_Spec), Formal_Type);
- end if;
-
- -- An access formal type
-
- else
- Formal_Type :=
- Access_Definition (Related_Nod, Parameter_Type (Param_Spec));
- end if;
-
- Set_Etype (Formal, Formal_Type);
-
- Default := Expression (Param_Spec);
-
- if Present (Default) then
- if Out_Present (Param_Spec) then
- Error_Msg_N
- ("default initialization only allowed for IN parameters",
- Param_Spec);
- end if;
-
- -- Do the special preanalysis of the expression (see section on
- -- "Handling of Default Expressions" in the spec of package Sem).
-
- Analyze_Default_Expression (Default, Formal_Type);
-
- -- Check that the designated type of an access parameter's
- -- default is not a class-wide type unless the parameter's
- -- designated type is also class-wide.
-
- if Ekind (Formal_Type) = E_Anonymous_Access_Type
- and then Is_Class_Wide_Type (Designated_Type (Etype (Default)))
- and then not Is_Class_Wide_Type (Designated_Type (Formal_Type))
- then
- Wrong_Type (Default, Formal_Type);
- end if;
- end if;
-
- <<Continue>>
- Next (Param_Spec);
- end loop;
-
- -- Now set the kind (mode) of each formal
-
- Param_Spec := First (T);
-
- while Present (Param_Spec) loop
- Formal := Defining_Identifier (Param_Spec);
- Set_Formal_Mode (Formal);
-
- if Ekind (Formal) = E_In_Parameter then
- Set_Default_Value (Formal, Expression (Param_Spec));
-
- if Present (Expression (Param_Spec)) then
- Default := Expression (Param_Spec);
-
- if Is_Scalar_Type (Etype (Default)) then
- if Nkind
- (Parameter_Type (Param_Spec)) /= N_Access_Definition
- then
- Formal_Type := Entity (Parameter_Type (Param_Spec));
-
- else
- Formal_Type := Access_Definition
- (Related_Nod, Parameter_Type (Param_Spec));
- end if;
-
- Apply_Scalar_Range_Check (Default, Formal_Type);
- end if;
-
- end if;
- end if;
-
- Next (Param_Spec);
- end loop;
-
- end Process_Formals;
-
- -------------------------
- -- Set_Actual_Subtypes --
- -------------------------
-
- procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id) is
- Loc : constant Source_Ptr := Sloc (N);
- Decl : Node_Id;
- Formal : Entity_Id;
- T : Entity_Id;
- First_Stmt : Node_Id := Empty;
- AS_Needed : Boolean;
-
- begin
- Formal := First_Formal (Subp);
- while Present (Formal) loop
- T := Etype (Formal);
-
- -- We never need an actual subtype for a constrained formal.
-
- if Is_Constrained (T) then
- AS_Needed := False;
-
- -- If we have unknown discriminants, then we do not need an
- -- actual subtype, or more accurately we cannot figure it out!
- -- Note that all class-wide types have unknown discriminants.
-
- elsif Has_Unknown_Discriminants (T) then
- AS_Needed := False;
-
- -- At this stage we have an unconstrained type that may need
- -- an actual subtype. For sure the actual subtype is needed
- -- if we have an unconstrained array type.
-
- elsif Is_Array_Type (T) then
- AS_Needed := True;
-
- -- The only other case which needs an actual subtype is an
- -- unconstrained record type which is an IN parameter (we
- -- cannot generate actual subtypes for the OUT or IN OUT case,
- -- since an assignment can change the discriminant values.
- -- However we exclude the case of initialization procedures,
- -- since discriminants are handled very specially in this context,
- -- see the section entitled "Handling of Discriminants" in Einfo.
- -- We also exclude the case of Discrim_SO_Functions (functions
- -- used in front end layout mode for size/offset values), since
- -- in such functions only discriminants are referenced, and not
- -- only are such subtypes not needed, but they cannot always
- -- be generated, because of order of elaboration issues.
-
- elsif Is_Record_Type (T)
- and then Ekind (Formal) = E_In_Parameter
- and then Chars (Formal) /= Name_uInit
- and then not Is_Discrim_SO_Function (Subp)
- then
- AS_Needed := True;
-
- -- All other cases do not need an actual subtype
-
- else
- AS_Needed := False;
- end if;
-
- -- Generate actual subtypes for unconstrained arrays and
- -- unconstrained discriminated records.
-
- if AS_Needed then
- Decl := Build_Actual_Subtype (T, Formal);
-
- if Nkind (N) = N_Accept_Statement then
- if Present (Handled_Statement_Sequence (N)) then
- First_Stmt :=
- First (Statements (Handled_Statement_Sequence (N)));
- Prepend (Decl, Statements (Handled_Statement_Sequence (N)));
- Mark_Rewrite_Insertion (Decl);
- else
- -- If the accept statement has no body, there will be
- -- no reference to the actuals, so no need to compute
- -- actual subtypes.
-
- return;
- end if;
-
- else
- Prepend (Decl, Declarations (N));
- Mark_Rewrite_Insertion (Decl);
- end if;
-
- Analyze (Decl);
-
- -- We need to freeze manually the generated type when it is
- -- inserted anywhere else than in a declarative part.
-
- if Present (First_Stmt) then
- Insert_List_Before_And_Analyze (First_Stmt,
- Freeze_Entity (Defining_Identifier (Decl), Loc));
- end if;
-
- Set_Actual_Subtype (Formal, Defining_Identifier (Decl));
- end if;
-
- Next_Formal (Formal);
- end loop;
- end Set_Actual_Subtypes;
-
- ---------------------
- -- Set_Formal_Mode --
- ---------------------
-
- procedure Set_Formal_Mode (Formal_Id : Entity_Id) is
- Spec : constant Node_Id := Parent (Formal_Id);
-
- begin
- -- Note: we set Is_Known_Valid for IN parameters and IN OUT parameters
- -- since we ensure that corresponding actuals are always valid at the
- -- point of the call.
-
- if Out_Present (Spec) then
-
- if Ekind (Scope (Formal_Id)) = E_Function
- or else Ekind (Scope (Formal_Id)) = E_Generic_Function
- then
- Error_Msg_N ("functions can only have IN parameters", Spec);
- Set_Ekind (Formal_Id, E_In_Parameter);
-
- elsif In_Present (Spec) then
- Set_Ekind (Formal_Id, E_In_Out_Parameter);
-
- else
- Set_Ekind (Formal_Id, E_Out_Parameter);
- Set_Not_Source_Assigned (Formal_Id);
- end if;
-
- else
- Set_Ekind (Formal_Id, E_In_Parameter);
- end if;
-
- Set_Mechanism (Formal_Id, Default_Mechanism);
- Set_Formal_Validity (Formal_Id);
- end Set_Formal_Mode;
-
- -------------------------
- -- Set_Formal_Validity --
- -------------------------
-
- procedure Set_Formal_Validity (Formal_Id : Entity_Id) is
- begin
- -- If in full validity checking mode, then we can assume that
- -- an IN or IN OUT parameter is valid (see Exp_Ch5.Expand_Call)
-
- if not Validity_Checks_On then
- return;
-
- elsif Ekind (Formal_Id) = E_In_Parameter
- and then Validity_Check_In_Params
- then
- Set_Is_Known_Valid (Formal_Id, True);
-
- elsif Ekind (Formal_Id) = E_In_Out_Parameter
- and then Validity_Check_In_Out_Params
- then
- Set_Is_Known_Valid (Formal_Id, True);
- end if;
- end Set_Formal_Validity;
-
- ------------------------
- -- Subtype_Conformant --
- ------------------------
-
- function Subtype_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
- Result : Boolean;
-
- begin
- Check_Conformance (New_Id, Old_Id, Subtype_Conformant, False, Result);
- return Result;
- end Subtype_Conformant;
-
- ---------------------
- -- Type_Conformant --
- ---------------------
-
- function Type_Conformant (New_Id, Old_Id : Entity_Id) return Boolean is
- Result : Boolean;
-
- begin
- Check_Conformance (New_Id, Old_Id, Type_Conformant, False, Result);
- return Result;
- end Type_Conformant;
-
- -------------------------------
- -- Valid_Operator_Definition --
- -------------------------------
-
- procedure Valid_Operator_Definition (Designator : Entity_Id) is
- N : Integer := 0;
- F : Entity_Id;
- Id : constant Name_Id := Chars (Designator);
- N_OK : Boolean;
-
- begin
- F := First_Formal (Designator);
-
- while Present (F) loop
- N := N + 1;
-
- if Present (Default_Value (F)) then
- Error_Msg_N
- ("default values not allowed for operator parameters",
- Parent (F));
- end if;
-
- Next_Formal (F);
- end loop;
-
- -- Verify that user-defined operators have proper number of arguments
- -- First case of operators which can only be unary
-
- if Id = Name_Op_Not
- or else Id = Name_Op_Abs
- then
- N_OK := (N = 1);
-
- -- Case of operators which can be unary or binary
-
- elsif Id = Name_Op_Add
- or Id = Name_Op_Subtract
- then
- N_OK := (N in 1 .. 2);
-
- -- All other operators can only be binary
-
- else
- N_OK := (N = 2);
- end if;
-
- if not N_OK then
- Error_Msg_N
- ("incorrect number of arguments for operator", Designator);
- end if;
-
- if Id = Name_Op_Ne
- and then Base_Type (Etype (Designator)) = Standard_Boolean
- and then not Is_Intrinsic_Subprogram (Designator)
- then
- Error_Msg_N
- ("explicit definition of inequality not allowed", Designator);
- end if;
- end Valid_Operator_Definition;
-
-end Sem_Ch6;
projects / msp430-gcc.git / blobdiff