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diff --git a/gcc-4.2.1/gcc/ada/sem_util.ads b/gcc-4.2.1/gcc/ada/sem_util.ads new file mode 100644 index 000000000..c6f847b11 --- /dev/null +++ b/gcc-4.2.1/gcc/ada/sem_util.ads @@ -0,0 +1,886 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- S E M _ U T I L -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2006, 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, 51 Franklin Street, Fifth Floor, -- +-- Boston, MA 02110-1301, 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_Obsolescent (Nam : Entity_Id; N : Node_Id); + -- Nam is either a subprogram or a (generic) package entity. This procedure + -- checks if the Is_Obsolescent flag is set and if so, outputs appropriate + -- diagnostics (it also checks the appropriate restriction). N is the node + -- to which error messages are attached. + + 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; + -- This is similar to Apply_Compile_Time_Constraint_Error in that it + -- generates a warning (or error) message in the same manner, but it does + -- not replace any nodes. 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 + (N : Node_Id) return Node_Id; + -- Returns the Node_Id associated with the innermost enclosing + -- generic body, if any. If none, then returns Empty. + + function Enclosing_Generic_Unit + (N : Node_Id) return Node_Id; + -- Returns the Node_Id associated with the innermost enclosing + -- generic unit, 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 : Entity_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. + -- The names in the string are generated by Namet.Get_Decoded_Name_String. + + 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_Discriminant_Dependent_Constraint + (Comp : Entity_Id) return Boolean; + -- Returns True if and only if Comp has a constrained subtype + -- that depends on a discriminant. + + 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_Controlling_Limited_Procedure + (Proc_Nam : Entity_Id) return Boolean; + -- Ada 2005 (AI-345): Determine whether Proc_Nam is a primitive procedure + -- of a limited interface with a controlling first parameter. + + 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_Potentially_Persistent_Type (T : Entity_Id) return Boolean; + -- Determines if type T is a potentially persistent type. A potentially + -- persistent type is defined (recursively) as a scalar type, a non-tagged + -- record whose components are all of a potentially persistent type, or an + -- array with all static constraints whose component type is potentially + -- persistent. A private type is potentially persistent if the full type + -- is potentially persistent. + + 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_Renamed_Entry (Proc_Nam : Entity_Id) return Boolean; + -- Return True if Proc_Nam is a procedure renaming of an entry + + 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_Current_Values (Ent : Entity_Id); + -- This performs the same processing as described above for the form with + -- no argument, but for the specific entity given. The call has no effect + -- if the entity Ent is not for an object. + + 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 that 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; |