------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ U T I L -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2004, 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. -- -- -- ------------------------------------------------------------------------------ -- Package containing utility procedures used throughout the semantics with Einfo; use Einfo; with Types; use Types; with Uintp; use Uintp; with Urealp; use Urealp; package Sem_Util is procedure Add_Access_Type_To_Process (E : Entity_Id; A : Entity_Id); -- Add A to the list of access types to process when expanding the -- freeze node of E. function Alignment_In_Bits (E : Entity_Id) return Uint; -- If the alignment of the type or object E is currently known to the -- compiler, then this function returns the alignment value in bits. -- Otherwise Uint_0 is returned, indicating that the alignment of the -- entity is not yet known to the compiler. procedure Apply_Compile_Time_Constraint_Error (N : Node_Id; Msg : String; Reason : RT_Exception_Code; Ent : Entity_Id := Empty; Typ : Entity_Id := Empty; Loc : Source_Ptr := No_Location; Rep : Boolean := True; Warn : Boolean := False); -- N is a subexpression which will raise constraint error when evaluated -- at runtime. Msg is a message that explains the reason for raising the -- exception. The last character is ? if the message is always a warning, -- even in Ada 95, and is not a ? if the message represents an illegality -- (because of violation of static expression rules) in Ada 95 (but not -- in Ada 83). Typically this routine posts all messages at the Sloc of -- node N. However, if Loc /= No_Location, Loc is the Sloc used to output -- the message. After posting the appropriate message, and if the flag -- Rep is set, this routine replaces the expression with an appropriate -- N_Raise_Constraint_Error node using the given Reason code. This node -- is then marked as being static if the original node is static, but -- sets the flag Raises_Constraint_Error, preventing further evaluation. -- The error message may contain a } or & insertion character. This -- normally references Etype (N), unless the Ent argument is given -- explicitly, in which case it is used instead. The type of the raise -- node that is built is normally Etype (N), but if the Typ parameter -- is present, this is used instead. Warn is normally False. If it is -- True then the message is treated as a warning even though it does -- not end with a ? (this is used when the caller wants to parametrize -- whether an error or warning is given. function Build_Actual_Subtype (T : Entity_Id; N : Node_Or_Entity_Id) return Node_Id; -- Build an anonymous subtype for an entity or expression, using the -- bounds of the entity or the discriminants of the enclosing record. -- T is the type for which the actual subtype is required, and N is either -- a defining identifier, or any subexpression. function Build_Actual_Subtype_Of_Component (T : Entity_Id; N : Node_Id) return Node_Id; -- Determine whether a selected component has a type that depends on -- discriminants, and build actual subtype for it if so. function Build_Discriminal_Subtype_Of_Component (T : Entity_Id) return Node_Id; -- Determine whether a record component has a type that depends on -- discriminants, and build actual subtype for it if so. procedure Build_Elaboration_Entity (N : Node_Id; Spec_Id : Entity_Id); -- Given a compilation unit node N, allocate an elaboration boolean for -- the compilation unit, and install it in the Elaboration_Entity field -- of Spec_Id, the entity for the compilation unit. function Cannot_Raise_Constraint_Error (Expr : Node_Id) return Boolean; -- Returns True if the expression cannot possibly raise Constraint_Error. -- The response is conservative in the sense that a result of False does -- not necessarily mean that CE could be raised, but a response of True -- means that for sure CE cannot be raised. procedure Check_Fully_Declared (T : Entity_Id; N : Node_Id); -- Verify that the full declaration of type T has been seen. If not, -- place error message on node N. Used in object declarations, type -- conversions, qualified expressions. procedure Check_Potentially_Blocking_Operation (N : Node_Id); -- N is one of the statement forms that is a potentially blocking -- operation. If it appears within a protected action, emit warning. procedure Check_VMS (Construct : Node_Id); -- Check that this the target is OpenVMS, and if so, return with -- no effect, otherwise post an error noting this can only be used -- with OpenVMS ports. The argument is the construct in question -- and is used to post the error message. function Collect_Primitive_Operations (T : Entity_Id) return Elist_Id; -- Called upon type derivation and extension. We scan the declarative -- part in which the type appears, and collect subprograms that have -- one subsidiary subtype of the type. These subprograms can only -- appear after the type itself. function Compile_Time_Constraint_Error (N : Node_Id; Msg : String; Ent : Entity_Id := Empty; Loc : Source_Ptr := No_Location; Warn : Boolean := False) return Node_Id; -- Subsidiary to Apply_Compile_Time_Constraint_Error and Checks routines. -- Does not modify any nodes, but generates a warning (or error) message. -- For convenience, the function always returns its first argument. The -- message is a warning if the message ends with ?, or we are operating -- in Ada 83 mode, or if the Warn parameter is set to True. procedure Conditional_Delay (New_Ent, Old_Ent : Entity_Id); -- Sets the Has_Delayed_Freeze flag of New if the Delayed_Freeze flag -- of Old is set and Old has no yet been Frozen (i.e. Is_Frozen is false); function Current_Entity (N : Node_Id) return Entity_Id; -- Find the currently visible definition for a given identifier, that is to -- say the first entry in the visibility chain for the Chars of N. function Current_Entity_In_Scope (N : Node_Id) return Entity_Id; -- Find whether there is a previous definition for identifier N in the -- current scope. Because declarations for a scope are not necessarily -- contiguous (e.g. for packages) the first entry on the visibility chain -- for N is not necessarily in the current scope. function Current_Scope return Entity_Id; -- Get entity representing current scope function Current_Subprogram return Entity_Id; -- Returns current enclosing subprogram. If Current_Scope is a subprogram, -- then that is what is returned, otherwise the Enclosing_Subprogram of -- the Current_Scope is returned. The returned value is Empty if this -- is called from a library package which is not within any subprogram. function Defining_Entity (N : Node_Id) return Entity_Id; -- Given a declaration N, returns the associated defining entity. If -- the declaration has a specification, the entity is obtained from -- the specification. If the declaration has a defining unit name, -- then the defining entity is obtained from the defining unit name -- ignoring any child unit prefixes. function Denotes_Discriminant (N : Node_Id; Check_Protected : Boolean := False) return Boolean; -- Returns True if node N is an Entity_Name node for a discriminant. -- If the flag Check_Protected is true, function also returns true -- when N denotes the discriminal of the discriminant of a protected -- type. This is necessary to disable some optimizations on private -- components of protected types. function Depends_On_Discriminant (N : Node_Id) return Boolean; -- Returns True if N denotes a discriminant or if N is a range, a subtype -- indication or a scalar subtype where one of the bounds is a -- discriminant. function Designate_Same_Unit (Name1 : Node_Id; Name2 : Node_Id) return Boolean; -- Return true if Name1 and Name2 designate the same unit name; -- each of these names is supposed to be a selected component name, -- an expanded name, a defining program unit name or an identifier function Enclosing_Generic_Body (E : Entity_Id) return Node_Id; -- Returns the Node_Id associated with the innermost enclosing -- generic body, if any. If none, then returns Empty. function Enclosing_Lib_Unit_Entity return Entity_Id; -- Returns the entity of enclosing N_Compilation_Unit Node which is the -- root of the current scope (which must not be Standard_Standard, and -- the caller is responsible for ensuring this condition). function Enclosing_Lib_Unit_Node (N : Node_Id) return Node_Id; -- Returns the enclosing N_Compilation_Unit Node that is the root -- of a subtree containing N. function Enclosing_Subprogram (E : Entity_Id) return Entity_Id; -- Utility function to return the Ada entity of the subprogram enclosing -- the entity E, if any. Returns Empty if no enclosing subprogram. procedure Ensure_Freeze_Node (E : Entity_Id); -- Make sure a freeze node is allocated for entity E. If necessary, -- build and initialize a new freeze node and set Has_Delayed_Freeze -- true for entity E. procedure Enter_Name (Def_Id : Node_Id); -- Insert new name in symbol table of current scope with check for -- duplications (error message is issued if a conflict is found) -- Note: Enter_Name is not used for overloadable entities, instead -- these are entered using Sem_Ch6.Enter_Overloadable_Entity. procedure Explain_Limited_Type (T : Entity_Id; N : Node_Id); -- This procedure is called after issuing a message complaining -- about an inappropriate use of limited type T. If useful, it -- adds additional continuation lines to the message explaining -- why type T is limited. Messages are placed at node N. function Find_Corresponding_Discriminant (Id : Node_Id; Typ : Entity_Id) return Entity_Id; -- Because discriminants may have different names in a generic unit -- and in an instance, they are resolved positionally when possible. -- A reference to a discriminant carries the discriminant that it -- denotes when analyzed. Subsequent uses of this id on a different -- type denote the discriminant at the same position in this new type. function First_Actual (Node : Node_Id) return Node_Id; -- Node is an N_Function_Call or N_Procedure_Call_Statement node. The -- result returned is the first actual parameter in declaration order -- (not the order of parameters as they appeared in the source, which -- can be quite different as a result of the use of named parameters). -- Empty is returned for a call with no parameters. The procedure for -- iterating through the actuals in declaration order is to use this -- function to find the first actual, and then use Next_Actual to obtain -- the next actual in declaration order. Note that the value returned -- is always the expression (not the N_Parameter_Association nodes -- even if named association is used). function Full_Qualified_Name (E : Entity_Id) return String_Id; -- Generates the string literal corresponding to the E's full qualified -- name in upper case. An ASCII.NUL is appended as the last character function Find_Static_Alternative (N : Node_Id) return Node_Id; -- N is a case statement whose expression is a compile-time value. -- Determine the alternative chosen, so that the code of non-selected -- alternatives, and the warnings that may apply to them, are removed. procedure Gather_Components (Typ : Entity_Id; Comp_List : Node_Id; Governed_By : List_Id; Into : Elist_Id; Report_Errors : out Boolean); -- The purpose of this procedure is to gather the valid components in a -- record type according to the values of its discriminants, in order to -- validate the components of a record aggregate. -- -- Typ is the type of the aggregate when its constrained discriminants -- need to be collected, otherwise it is Empty. -- -- Comp_List is an N_Component_List node. -- -- Governed_By is a list of N_Component_Association nodes, where each -- choice list contains the name of a discriminant and the expression -- field gives its value. The values of the discriminants governing -- the (possibly nested) variant parts in Comp_List are found in this -- Component_Association List. -- -- Into is the list where the valid components are appended. Note that -- Into need not be an Empty list. If it's not, components are attached -- to its tail. -- -- Report_Errors is set to True if the values of the discriminants are -- non-static. -- -- This procedure is also used when building a record subtype. If the -- discriminant constraint of the subtype is static, the components of the -- subtype are only those of the variants selected by the values of the -- discriminants. Otherwise all components of the parent must be included -- in the subtype for semantic analysis. function Get_Actual_Subtype (N : Node_Id) return Entity_Id; -- Given a node for an expression, obtain the actual subtype of the -- expression. In the case of a parameter where the formal is an -- unconstrained array or discriminated type, this will be the -- previously constructed subtype of the actual. Note that this is -- not quite the "Actual Subtype" of the RM, since it is always -- a constrained type, i.e. it is the subtype of the value of the -- actual. The actual subtype is also returned in other cases where -- it has already been constructed for an object. Otherwise the -- expression type is returned unchanged, except for the case of an -- unconstrained array type, where an actual subtype is created, using -- Insert_Actions if necessary to insert any associated actions. function Get_Actual_Subtype_If_Available (N : Node_Id) return Entity_Id; -- This is like Get_Actual_Subtype, except that it never constructs an -- actual subtype. If an actual subtype is already available, i.e. the -- Actual_Subtype field of the corresponding entity is set, then it is -- returned. Otherwise the Etype of the node is returned. function Get_Default_External_Name (E : Node_Or_Entity_Id) return Node_Id; -- This is used to construct the string literal node representing a -- default external name, i.e. one that is constructed from the name -- of an entity, or (in the case of extended DEC import/export pragmas, -- an identifier provided as the external name. Letters in the name are -- according to the setting of Opt.External_Name_Default_Casing. function Get_Generic_Entity (N : Node_Id) return Entity_Id; -- Returns the true generic entity in an instantiation. If the name in -- the instantiation is a renaming, the function returns the renamed -- generic. procedure Get_Index_Bounds (N : Node_Id; L, H : out Node_Id); -- This procedure assigns to L and H respectively the values of the -- low and high bounds of node N, which must be a range, subtype -- indication, or the name of a scalar subtype. The result in L, H -- may be set to Error if there was an earlier error in the range. function Get_Enum_Lit_From_Pos (T : Entity_Id; Pos : Uint; Loc : Source_Ptr) return Entity_Id; -- This function obtains the E_Enumeration_Literal entity for the -- specified value from the enumneration type or subtype T. The -- second argument is the Pos value, which is assumed to be in range. -- The third argument supplies a source location for constructed -- nodes returned by this function. procedure Get_Library_Unit_Name_String (Decl_Node : Node_Id); -- Retrieve the fully expanded name of the library unit declared by -- Decl_Node into the name buffer. function Get_Name_Entity_Id (Id : Name_Id) return Entity_Id; -- An entity value is associated with each name in the name table. The -- Get_Name_Entity_Id function fetches the Entity_Id of this entity, -- which is the innermost visible entity with the given name. See the -- body of Sem_Ch8 for further details on handling of entity visibility. function Get_Referenced_Object (N : Node_Id) return Node_Id; -- Given a node, return the renamed object if the node represents -- a renamed object, otherwise return the node unchanged. The node -- may represent an arbitrary expression. function Get_Subprogram_Body (E : Entity_Id) return Node_Id; -- Given the entity for a subprogram (E_Function or E_Procedure), -- return the corresponding N_Subprogram_Body node. If the corresponding -- body of the declaration is missing (as for an imported subprogram) -- return Empty. function Get_Task_Body_Procedure (E : Entity_Id) return Node_Id; pragma Inline (Get_Task_Body_Procedure); -- Given an entity for a task type or subtype, retrieves the -- Task_Body_Procedure field from the corresponding task type -- declaration. function Has_Access_Values (T : Entity_Id) return Boolean; -- Returns true if type or subtype T is an access type, or has a -- component (at any recursive level) that is an access type. This -- is a conservative predicate, if it is not known whether or not -- T contains access values (happens for generic formals in some -- cases), then False is returned. function Has_Declarations (N : Node_Id) return Boolean; -- Determines if the node can have declarations function Has_Infinities (E : Entity_Id) return Boolean; -- Determines if the range of the floating-point type E includes -- infinities. Returns False if E is not a floating-point type. function Has_Private_Component (Type_Id : Entity_Id) return Boolean; -- Check if a type has a (sub)component of a private type that has not -- yet received a full declaration. function Has_Stream (T : Entity_Id) return Boolean; -- Tests if type T is derived from Ada.Streams.Root_Stream_Type, or -- in the case of a composite type, has a component for which this -- predicate is True, and if so returns True. Otherwise a result of -- False means that there is no Stream type in sight. For a private -- type, the test is applied to the underlying type (or returns False -- if there is no underlying type). function Has_Tagged_Component (Typ : Entity_Id) return Boolean; -- Typ must be a composite type (array or record). This function is used -- to check if '=' has to be expanded into a bunch component comparaisons. function In_Instance return Boolean; -- Returns True if the current scope is within a generic instance. function In_Instance_Body return Boolean; -- Returns True if current scope is within the body of an instance, where -- several semantic checks (e.g. accessibility checks) are relaxed. function In_Instance_Not_Visible return Boolean; -- Returns True if current scope is with the private part or the body of -- an instance. Other semantic checks are suppressed in this context. function In_Instance_Visible_Part return Boolean; -- Returns True if current scope is within the visible part of a package -- instance, where several additional semantic checks apply. function In_Package_Body return Boolean; -- Returns True if current scope is within a package body function In_Subprogram_Or_Concurrent_Unit return Boolean; -- Determines if the current scope is within a subprogram compilation -- unit (inside a subprogram declaration, subprogram body, or generic -- subprogram declaration) or within a task or protected body. The test -- is for appearing anywhere within such a construct (that is it does not -- need to be directly within). function In_Visible_Part (Scope_Id : Entity_Id) return Boolean; -- Determine whether a declaration occurs within the visible part of a -- package specification. The package must be on the scope stack, and the -- corresponding private part must not. procedure Insert_Explicit_Dereference (N : Node_Id); -- In a context that requires a composite or subprogram type and -- where a prefix is an access type, rewrite the access type node -- N (which is the prefix, e.g. of an indexed component) as an -- explicit dereference. function Is_AAMP_Float (E : Entity_Id) return Boolean; -- Defined for all type entities. Returns True only for the base type -- of float types with AAMP format. The particular format is determined -- by the Digits_Value value which is 6 for the 32-bit floating point type, -- or 9 for the 48-bit type. This is not an attribute function (like -- VAX_Float) in order to not use up an extra flag and to prevent -- the dependency of Einfo on Targparm which would be required for a -- synthesized attribute. function Is_Actual_Parameter (N : Node_Id) return Boolean; -- Determines if N is an actual parameter in a subprogram call. function Is_Aliased_View (Obj : Node_Id) return Boolean; -- Determine if Obj is an aliased view, i.e. the name of an -- object to which 'Access or 'Unchecked_Access can apply. function Is_Ancestor_Package (E1 : Entity_Id; E2 : Entity_Id) return Boolean; -- Determine whether package E1 is an ancestor of E2 function Is_Atomic_Object (N : Node_Id) return Boolean; -- Determines if the given node denotes an atomic object in the sense -- of the legality checks described in RM C.6(12). function Is_Dependent_Component_Of_Mutable_Object (Object : Node_Id) return Boolean; -- Returns True if Object is the name of a subcomponent that -- depends on discriminants of a variable whose nominal subtype -- is unconstrained and not indefinite, and the variable is -- not aliased. Otherwise returns False. The nodes passed -- to this function are assumed to denote objects. function Is_Dereferenced (N : Node_Id) return Boolean; -- N is a subexpression node of an access type. This function returns -- true if N appears as the prefix of a node that does a dereference -- of the access value (selected/indexed component, explicit dereference -- or a slice), and false otherwise. function Is_Descendent_Of (T1 : Entity_Id; T2 : Entity_Id) return Boolean; -- Returns True if type T1 is a descendent of type T2, and false otherwise. -- This is the RM definition, a type is a descendent of another type if it -- is the same type or is derived from a descendent of the other type. function Is_Descendent_Of_Address (T1 : Entity_Id) return Boolean; -- Returns True if type T1 is a descendent of Address or its base type. -- Similar to calling Is_Descendent_Of with Base_Type (RTE (RE_Address)) -- except that it avoids creating an unconditional dependency on System. function Is_False (U : Uint) return Boolean; -- The argument is a Uint value which is the Boolean'Pos value of a -- Boolean operand (i.e. is either 0 for False, or 1 for True). This -- function simply tests if it is False (i.e. zero) function Is_Fixed_Model_Number (U : Ureal; T : Entity_Id) return Boolean; -- Returns True iff the number U is a model number of the fixed- -- point type T, i.e. if it is an exact multiple of Small. function Is_Fully_Initialized_Type (Typ : Entity_Id) return Boolean; -- Typ is a type entity. This function returns true if this type is -- fully initialized, meaning that an object of the type is fully -- initialized. Note that initialization resulting from the use of -- pragma Normalized_Scalars does not count. Note that this is only -- used for the purpose of issuing warnings for objects that are -- potentially referenced uninitialized. This means that the result -- returned is not crucial, but probably should err on the side of -- thinking things are fully initialized if it does not know. function Is_Inherited_Operation (E : Entity_Id) return Boolean; -- E is a subprogram. Return True is E is an implicit operation inherited -- by a derived type declarations. function Is_Lvalue (N : Node_Id) return Boolean; -- Determines if N could be an lvalue (e.g. an assignment left hand side). -- This determination is conservative, it must never answer False if N is -- an lvalue, but it can answer True when N is not an lvalue. An lvalue is -- defined as any expression which appears in a context where a name is -- required by the syntax, and the identity, rather than merely the value -- of the node is needed (for example, the prefix of an Access attribute -- is in this category). function Is_Library_Level_Entity (E : Entity_Id) return Boolean; -- A library-level declaration is one that is accessible from Standard, -- i.e. a library unit or an entity declared in a library package. function Is_Local_Variable_Reference (Expr : Node_Id) return Boolean; -- Determines whether Expr is a refeference to a variable or IN OUT -- mode parameter of the current enclosing subprogram. -- Why are OUT parameters not considered here ??? function Is_Object_Reference (N : Node_Id) return Boolean; -- Determines if the tree referenced by N represents an object. Both -- variable and constant objects return True (compare Is_Variable). function Is_OK_Variable_For_Out_Formal (AV : Node_Id) return Boolean; -- Used to test if AV is an acceptable formal for an OUT or IN OUT -- formal. Note that the Is_Variable function is not quite the right -- test because this is a case in which conversions whose expression -- is a variable (in the Is_Variable sense) with a non-tagged type -- target are considered view conversions and hence variables. function Is_Partially_Initialized_Type (Typ : Entity_Id) return Boolean; -- Typ is a type entity. This function returns true if this type is -- partly initialized, meaning that an object of the type is at least -- partly initialized (in particular in the record case, that at least -- one field has an initialization expression). Note that initialization -- resulting from the use of pragma Normalized_Scalars does not count. function Is_RCI_Pkg_Spec_Or_Body (Cunit : Node_Id) return Boolean; -- Return True if a compilation unit is the specification or the -- body of a remote call interface package. function Is_Remote_Access_To_Class_Wide_Type (E : Entity_Id) return Boolean; -- Return True if E is a remote access-to-class-wide-limited_private type function Is_Remote_Access_To_Subprogram_Type (E : Entity_Id) return Boolean; -- Return True if E is a remote access to subprogram type. function Is_Remote_Call (N : Node_Id) return Boolean; -- Return True if N denotes a potentially remote call function Is_Selector_Name (N : Node_Id) return Boolean; -- Given an N_Identifier node N, determines if it is a Selector_Name. -- As described in Sinfo, Selector_Names are special because they -- represent use of the N_Identifier node for a true identifer, when -- normally such nodes represent a direct name. function Is_Statement (N : Node_Id) return Boolean; -- Check if the node N is a statement node. Note that this includes -- the case of procedure call statements (unlike the direct use of -- the N_Statement_Other_Than_Procedure_Call subtype from Sinfo). -- Note that a label is *not* a statement, and will return False. function Is_Transfer (N : Node_Id) return Boolean; -- Returns True if the node N is a statement which is known to cause -- an unconditional transfer of control at runtime, i.e. the following -- statement definitely will not be executed. function Is_True (U : Uint) return Boolean; -- The argument is a Uint value which is the Boolean'Pos value of a -- Boolean operand (i.e. is either 0 for False, or 1 for True). This -- function simply tests if it is True (i.e. non-zero) function Is_Variable (N : Node_Id) return Boolean; -- Determines if the tree referenced by N represents a variable, i.e. -- can appear on the left side of an assignment. There is one situation, -- namely formal parameters, in which non-tagged type conversions are -- also considered variables, but Is_Variable returns False for such -- cases, since it has no knowledge of the context. Note that this is -- the point at which Assignment_OK is checked, and True is returned -- for any tree thus marked. function Is_Volatile_Object (N : Node_Id) return Boolean; -- Determines if the given node denotes an volatile object in the sense -- of the legality checks described in RM C.6(12). Note that the test -- here is for something actually declared as volatile, not for an object -- that gets treated as volatile (see Einfo.Treat_As_Volatile). procedure Kill_Current_Values; -- This procedure is called to clear all constant indications from all -- entities in the current scope and in any parent scopes if the current -- scope is a block or a pacakage (and that recursion continues to the -- top scope that is not a block or a package). This is used when the -- sequential flow-of-control assumption is violated (occurence of a -- label, head of a loop, or start of an exception handler). The effect -- of the call is to clear the Constant_Value field (but we do not need -- to clear the Is_True_Constant flag, since that only gets reset if -- there really is an assignment somewhere in the entity scope). This -- procedure also calls Kill_All_Checks, since this is a special case -- of needing to forget saved values. This procedure also clears any -- Is_Known_Non_Null flags in variables, constants or parameters -- since these are also not known to be valid. procedure Kill_Size_Check_Code (E : Entity_Id); -- Called when an address clause or pragma Import is applied to an -- entity. If the entity is a variable or a constant, and size check -- code is present, this size check code is killed, since the object -- will not be allocated by the program. function New_External_Entity (Kind : Entity_Kind; Scope_Id : Entity_Id; Sloc_Value : Source_Ptr; Related_Id : Entity_Id; Suffix : Character; Suffix_Index : Nat := 0; Prefix : Character := ' ') return Entity_Id; -- This function creates an N_Defining_Identifier node for an internal -- created entity, such as an implicit type or subtype, or a record -- initialization procedure. The entity name is constructed with a call -- to New_External_Name (Related_Id, Suffix, Suffix_Index, Prefix), so -- that the generated name may be referenced as a public entry, and the -- Is_Public flag is set if needed (using Set_Public_Status). If the -- entity is for a type or subtype, the size/align fields are initialized -- to unknown (Uint_0). function New_Internal_Entity (Kind : Entity_Kind; Scope_Id : Entity_Id; Sloc_Value : Source_Ptr; Id_Char : Character) return Entity_Id; -- This function is similar to New_External_Entity, except that the -- name is constructed by New_Internal_Name (Id_Char). This is used -- when the resulting entity does not have to be referenced as a -- public entity (and in this case Is_Public is not set). procedure Next_Actual (Actual_Id : in out Node_Id); pragma Inline (Next_Actual); -- Next_Actual (N) is equivalent to N := Next_Actual (N) function Next_Actual (Actual_Id : Node_Id) return Node_Id; -- Find next actual parameter in declaration order. As described for -- First_Actual, this is the next actual in the declaration order, not -- the call order, so this does not correspond to simply taking the -- next entry of the Parameter_Associations list. The argument is an -- actual previously returned by a call to First_Actual or Next_Actual. -- Note tha the result produced is always an expression, not a parameter -- assciation node, even if named notation was used. procedure Normalize_Actuals (N : Node_Id; S : Entity_Id; Report : Boolean; Success : out Boolean); -- Reorders lists of actuals according to names of formals, value returned -- in Success indicates sucess of reordering. For more details, see body. -- Errors are reported only if Report is set to True. procedure Note_Possible_Modification (N : Node_Id); -- This routine is called if the sub-expression N maybe the target of -- an assignment (e.g. it is the left side of an assignment, used as -- an out parameters, or used as prefixes of access attributes). It -- sets May_Be_Modified in the associated entity if there is one, -- taking into account the rule that in the case of renamed objects, -- it is the flag in the renamed object that must be set. function Object_Access_Level (Obj : Node_Id) return Uint; -- Return the accessibility level of the view of the object Obj. -- For convenience, qualified expressions applied to object names -- are also allowed as actuals for this function. function Private_Component (Type_Id : Entity_Id) return Entity_Id; -- Returns some private component (if any) of the given Type_Id. -- Used to enforce the rules on visibility of operations on composite -- types, that depend on the full view of the component type. For a -- record type there may be several such components, we just return -- the first one. procedure Process_End_Label (N : Node_Id; Typ : Character; Ent : Entity_Id); -- N is a node whose End_Label is to be processed, generating all -- appropriate cross-reference entries, and performing style checks -- for any identifier references in the end label. Typ is either -- 'e' or 't indicating the type of the cross-reference entity -- (e for spec, t for body, see Lib.Xref spec for details). The -- parameter Ent gives the entity to which the End_Label refers, -- and to which cross-references are to be generated. function Real_Convert (S : String) return Node_Id; -- S is a possibly signed syntactically valid real literal. The result -- returned is an N_Real_Literal node representing the literal value. function Rep_To_Pos_Flag (E : Entity_Id; Loc : Source_Ptr) return Node_Id; -- This is used to construct the second argument in a call to Rep_To_Pos -- which is Standard_True if range checks are enabled (E is an entity to -- which the Range_Checks_Suppressed test is applied), and Standard_False -- if range checks are suppressed. Loc is the location for the node that -- is returned (which is a New_Occurrence of the appropriate entity). -- -- Note: one might think that it would be fine to always use True and -- to ignore the suppress in this case, but it is generally better to -- believe a request to suppress exceptions if possible, and further -- more there is at least one case in the generated code (the code for -- array assignment in a loop) that depends on this suppression. procedure Require_Entity (N : Node_Id); -- N is a node which should have an entity value if it is an entity name. -- If not, then check if there were previous errors. If so, just fill -- in with Any_Id and ignore. Otherwise signal a program error exception. -- This is used as a defense mechanism against ill-formed trees caused by -- previous errors (particularly in -gnatq mode). function Requires_Transient_Scope (Id : Entity_Id) return Boolean; -- E is a type entity. The result is True when temporaries of this -- type need to be wrapped in a transient scope to be reclaimed -- properly when a secondary stack is in use. Examples of types -- requiring such wrapping are controlled types and variable-sized -- types including unconstrained arrays procedure Reset_Analyzed_Flags (N : Node_Id); -- Reset the Analyzed flags in all nodes of the tree whose root is N function Safe_To_Capture_Value (N : Node_Id; Ent : Entity_Id) return Boolean; -- The caller is interested in capturing a value (either the current -- value, or an indication that the value is non-null) for the given -- entity Ent. This value can only be captured if sequential execution -- semantics can be properly guaranteed so that a subsequent reference -- will indeed be sure that this current value indication is correct. -- The node N is the construct which resulted in the possible capture -- of the value (this is used to check if we are in a conditional). function Same_Name (N1, N2 : Node_Id) return Boolean; -- Determine if two (possibly expanded) names are the same name function Same_Type (T1, T2 : Entity_Id) return Boolean; -- Determines if T1 and T2 represent exactly the same type. Two types -- are the same if they are identical, or if one is an unconstrained -- subtype of the other, or they are both common subtypes of the same -- type with identical constraints. The result returned is conservative. -- It is True if the types are known to be the same, but a result of -- False is indecisive (e.g. the compiler may not be able to tell that -- two constraints are identical). function Scope_Within_Or_Same (Scope1, Scope2 : Entity_Id) return Boolean; -- Determines if the entity Scope1 is the same as Scope2, or if it is -- inside it, where both entities represent scopes. Note that scopes -- are only partially ordered, so Scope_Within_Or_Same (A,B) and -- Scope_Within_Or_Same (B,A) can both be False for a given pair A,B. function Scope_Within (Scope1, Scope2 : Entity_Id) return Boolean; -- Like Scope_Within_Or_Same, except that this function returns -- False in the case where Scope1 and Scope2 are the same scope. procedure Set_Current_Entity (E : Entity_Id); -- Establish the entity E as the currently visible definition of its -- associated name (i.e. the Node_Id associated with its name) procedure Set_Entity_With_Style_Check (N : Node_Id; Val : Entity_Id); -- This procedure has the same calling sequence as Set_Entity, but -- if Style_Check is set, then it calls a style checking routine which -- can check identifier spelling style. procedure Set_Name_Entity_Id (Id : Name_Id; Val : Entity_Id); -- Sets the Entity_Id value associated with the given name, which is the -- Id of the innermost visible entity with the given name. See the body -- of package Sem_Ch8 for further details on the handling of visibility. procedure Set_Next_Actual (Ass1_Id : Node_Id; Ass2_Id : Node_Id); -- The arguments may be parameter associations, whose descendants -- are the optional formal name and the actual parameter. Positional -- parameters are already members of a list, and do not need to be -- chained separately. See also First_Actual and Next_Actual. procedure Set_Public_Status (Id : Entity_Id); -- If an entity (visible or otherwise) is defined in a library -- package, or a package that is itself public, then this subprogram -- labels the entity public as well. procedure Set_Scope_Is_Transient (V : Boolean := True); -- Set the flag Is_Transient of the current scope procedure Set_Size_Info (T1, T2 : Entity_Id); -- Copies the Esize field and Has_Biased_Representation flag from -- (sub)type entity T2 to (sub)type entity T1. Also copies the -- Is_Unsigned_Type flag in the fixed-point and discrete cases, -- and also copies the alignment value from T2 to T1. It does NOT -- copy the RM_Size field, which must be separately set if this -- is required to be copied also. function Scope_Is_Transient return Boolean; -- True if the current scope is transient. function Static_Integer (N : Node_Id) return Uint; -- This function analyzes the given expression node and then resolves it -- as any integer type. If the result is static, then the value of the -- universal expression is returned, otherwise an error message is output -- and a value of No_Uint is returned. function Statically_Different (E1, E2 : Node_Id) return Boolean; -- Return True if it can be statically determined that the Expressions -- E1 and E2 refer to different objects function Subprogram_Access_Level (Subp : Entity_Id) return Uint; -- Return the accessibility level of the view denoted by Subp. procedure Trace_Scope (N : Node_Id; E : Entity_Id; Msg : String); -- Print debugging information on entry to each unit being analyzed. procedure Transfer_Entities (From : Entity_Id; To : Entity_Id); -- Move a list of entities from one scope to another, and recompute -- Is_Public based upon the new scope. function Type_Access_Level (Typ : Entity_Id) return Uint; -- Return the accessibility level of Typ function Unit_Declaration_Node (Unit_Id : Entity_Id) return Node_Id; -- Unit_Id is the simple name of a program unit, this function returns -- the corresponding xxx_Declaration node for the entity. Also applies -- to the body entities for subprograms, tasks and protected units, in -- which case it returns the subprogram, task or protected body node -- for it. The unit may be a child unit with any number of ancestors. function Universal_Interpretation (Opnd : Node_Id) return Entity_Id; -- Yields universal_Integer or Universal_Real if this is a candidate. function Within_Init_Proc return Boolean; -- Determines if Current_Scope is within an init proc procedure Wrong_Type (Expr : Node_Id; Expected_Type : Entity_Id); -- Output error message for incorrectly typed expression. Expr is the -- node for the incorrectly typed construct (Etype (Expr) is the type -- found), and Expected_Type is the entity for the expected type. Note -- that Expr does not have to be a subexpression, anything with an -- Etype field may be used. private pragma Inline (Current_Entity); pragma Inline (Get_Name_Entity_Id); pragma Inline (Is_False); pragma Inline (Is_Statement); pragma Inline (Is_True); pragma Inline (Set_Current_Entity); pragma Inline (Set_Name_Entity_Id); pragma Inline (Set_Size_Info); end Sem_Util;