------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ P R A G -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2014, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- Pragma handling is isolated in a separate package -- (logically this processing belongs in chapter 4) with Namet; use Namet; with Opt; use Opt; with Snames; use Snames; with Types; use Types; package Sem_Prag is -- The following table lists all pragmas that act as an assertion -- expression. Assertion_Expression_Pragma : constant array (Pragma_Id) of Boolean := (Pragma_Assert => True, Pragma_Assert_And_Cut => True, Pragma_Assume => True, Pragma_Check => True, Pragma_Contract_Cases => True, Pragma_Initial_Condition => True, Pragma_Invariant => True, Pragma_Loop_Invariant => True, Pragma_Loop_Variant => True, Pragma_Post => True, Pragma_Post_Class => True, Pragma_Postcondition => True, Pragma_Pre => True, Pragma_Pre_Class => True, Pragma_Precondition => True, Pragma_Predicate => True, Pragma_Refined_Post => True, Pragma_Test_Case => True, Pragma_Type_Invariant => True, Pragma_Type_Invariant_Class => True, others => False); -- The following table lists all the implementation-defined pragmas that -- may apply to a body stub (no language defined pragmas apply). The table -- should be synchronized with Aspect_On_Body_Or_Stub_OK in unit Aspects if -- the pragmas below implement an aspect. Pragma_On_Body_Or_Stub_OK : constant array (Pragma_Id) of Boolean := (Pragma_Refined_Depends => True, Pragma_Refined_Global => True, Pragma_Refined_Post => True, Pragma_SPARK_Mode => True, Pragma_Warnings => True, others => False); ----------------- -- Subprograms -- ----------------- procedure Analyze_Pragma (N : Node_Id); -- Analyze procedure for pragma reference node N procedure Analyze_Contract_Cases_In_Decl_Part (N : Node_Id); -- Perform full analysis and expansion of delayed pragma Contract_Cases procedure Analyze_Depends_In_Decl_Part (N : Node_Id); -- Perform full analysis of delayed pragma Depends. This routine is also -- capable of performing basic analysis of pragma Refined_Depends. procedure Analyze_External_Property_In_Decl_Part (N : Node_Id; Expr_Val : out Boolean); -- Perform full analysis of delayed pragmas Async_Readers, Async_Writers, -- Effective_Reads and Effective_Writes. Flag Expr_Val contains the Boolean -- argument of the pragma or a default True if no argument is present. procedure Analyze_Global_In_Decl_Part (N : Node_Id); -- Perform full analysis of delayed pragma Global. This routine is also -- capable of performing basic analysis of pragma Refind_Global. procedure Analyze_Initial_Condition_In_Decl_Part (N : Node_Id); -- Perform full analysis of delayed pragma Initial_Condition procedure Analyze_Initializes_In_Decl_Part (N : Node_Id); -- Perform full analysis of delayed pragma Initializes procedure Analyze_Pre_Post_Condition_In_Decl_Part (Prag : Node_Id; Subp_Id : Entity_Id); -- Perform preanalysis of a [refined] precondition or postcondition that -- appears on a subprogram declaration or body [stub]. Prag denotes the -- pragma, Subp_Id is the entity of the related subprogram. The preanalysis -- of the expression is done as "spec expression" (see section "Handling -- of Default and Per-Object Expressions in Sem). procedure Analyze_Refined_Depends_In_Decl_Part (N : Node_Id); -- Preform full analysis of delayed pragma Refined_Depends. This routine -- uses Analyze_Depends_In_Decl_Part as a starting point, then performs -- various consistency checks between Depends and Refined_Depends. procedure Analyze_Refined_Global_In_Decl_Part (N : Node_Id); -- Perform full analysis of delayed pragma Refined_Global. This routine -- uses Analyze_Global_In_Decl_Part as a starting point, then performs -- various consistency checks between Global and Refined_Global. procedure Analyze_Refined_State_In_Decl_Part (N : Node_Id); -- Perform full analysis of delayed pragma Refined_State procedure Analyze_Test_Case_In_Decl_Part (N : Node_Id; S : Entity_Id); -- Perform preanalysis of pragma Test_Case that applies to a subprogram -- declaration. Parameter N denotes the pragma, S is the entity of the -- related subprogram. The preanalysis of the expression is done as "spec -- expression" (see section "Handling of Default and Per-Object Expressions -- in Sem). procedure Check_Applicable_Policy (N : Node_Id); -- N is either an N_Aspect or an N_Pragma node. There are two cases. If -- the name of the aspect or pragma is not one of those recognized as -- an assertion kind by an Assertion_Policy pragma, then the call has -- no effect. Note that in the case of a pragma derived from an aspect, -- the name we use for the purpose of this procedure is the aspect name, -- which may be different from the pragma name (e.g. Precondition for -- Pre aspect). In addition, 'Class aspects are recognized (and the -- corresponding special names used in the processing). -- -- If the name is a valid assertion kind name, then the Check_Policy pragma -- chain is checked for a matching entry (or for an Assertion entry which -- matches all possibilities). If a matching entry is found then the policy -- is checked. If it is On or Check, then the Is_Checked flag is set in -- the aspect or pragma node. If it is Off, Ignore, or Disable, then the -- Is_Ignored flag is set in the aspect or pragma node. Additionally for -- policy Disable, the Is_Disabled flag is set. -- -- If no matching Check_Policy pragma is found then the effect depends on -- whether -gnata was used, if so, then the call has no effect, otherwise -- Is_Ignored (but not Is_Disabled) is set True. procedure Check_External_Properties (Item : Node_Id; AR : Boolean; AW : Boolean; ER : Boolean; EW : Boolean); -- Flags AR, AW, ER and EW denote the static values of external properties -- Async_Readers, Async_Writers, Effective_Reads and Effective_Writes. Item -- is the related variable or state. Ensure legality of the combination and -- issue an error for an illegal combination. procedure Check_Missing_Part_Of (Item_Id : Entity_Id); -- Determine whether the placement within the state space of an abstract -- state, variable or package instantiation denoted by Item_Id requires the -- use of indicator/option Part_Of. If this is the case, emit an error. procedure Collect_Subprogram_Inputs_Outputs (Subp_Id : Entity_Id; Synthesize : Boolean := False; Subp_Inputs : in out Elist_Id; Subp_Outputs : in out Elist_Id; Global_Seen : out Boolean); -- Subsidiary to the analysis of pragmas Depends, Global, Refined_Depends -- and Refined_Global. The routine is also used by GNATprove. Collect all -- inputs and outputs of subprogram Subp_Id in lists Subp_Inputs (inputs) -- and Subp_Outputs (outputs). The inputs and outputs are gathered from: -- 1) The formal parameters of the subprogram -- 2) The items of pragma [Refined_]Global -- or -- 3) The items of pragma [Refined_]Depends if there is no pragma -- [Refined_]Global present and flag Synthesize is set to True. -- If the subprogram has no inputs and/or outputs, then the returned list -- is No_Elist. Flag Global_Seen is set when the related subprogram has -- pragma [Refined_]Global. function Delay_Config_Pragma_Analyze (N : Node_Id) return Boolean; -- N is a pragma appearing in a configuration pragma file. Most such -- pragmas are analyzed when the file is read, before parsing and analyzing -- the main unit. However, the analysis of certain pragmas results in -- adding information to the compiled main unit, and this cannot be done -- till the main unit is processed. Such pragmas return True from this -- function and in Frontend pragmas where Delay_Config_Pragma_Analyze is -- True have their analysis delayed until after the main program is parsed -- and analyzed. function Get_SPARK_Mode_From_Pragma (N : Node_Id) return SPARK_Mode_Type; -- Given a pragma SPARK_Mode node, return corresponding mode id procedure Initialize; -- Initializes data structures used for pragma processing. Must be called -- before analyzing each new main source program. function Is_Config_Static_String (Arg : Node_Id) return Boolean; -- This is called for a configuration pragma that requires either string -- literal or a concatenation of string literals. We cannot use normal -- static string processing because it is too early in the case of the -- pragma appearing in a configuration pragmas file. If Arg is of an -- appropriate form, then this call obtains the string (doing any necessary -- concatenations) and places it in Name_Buffer, setting Name_Len to its -- length, and then returns True. If it is not of the correct form, then an -- appropriate error message is posted, and False is returned. function Is_Elaboration_SPARK_Mode (N : Node_Id) return Boolean; -- Determine whether pragma SPARK_Mode appears in the statement part of a -- package body. function Is_Non_Significant_Pragma_Reference (N : Node_Id) return Boolean; -- The node N is a node for an entity and the issue is whether the -- occurrence is a reference for the purposes of giving warnings about -- unreferenced variables. This function returns True if the reference is -- not a reference from this point of view (e.g. the occurrence in a pragma -- Pack) and False if it is a real reference (e.g. the occurrence in a -- pragma Export); function Is_Pragma_String_Literal (Par : Node_Id) return Boolean; -- Given an N_Pragma_Argument_Association node, Par, which has the form of -- an operator symbol, determines whether or not it should be treated as an -- string literal. This is called by Sem_Ch6.Analyze_Operator_Symbol. If -- True is returned, the argument is converted to a string literal. If -- False is returned, then the argument is treated as an entity reference -- to the operator. function Is_Private_SPARK_Mode (N : Node_Id) return Boolean; -- Determine whether pragma SPARK_Mode appears in the private part of a -- package. function Is_Valid_Assertion_Kind (Nam : Name_Id) return Boolean; -- Returns True if Nam is one of the names recognized as a valid assertion -- kind by the Assertion_Policy pragma. Note that the 'Class cases are -- represented by the corresponding special names Name_uPre, Name_uPost, -- Name_uInviarnat, and Name_uType_Invariant (_Pre, _Post, _Invariant, -- and _Type_Invariant). procedure Make_Aspect_For_PPC_In_Gen_Sub_Decl (Decl : Node_Id); -- This routine makes aspects from precondition or postcondition pragmas -- that appear within a generic subprogram declaration. Decl is the generic -- subprogram declaration node. Note that the aspects are attached to the -- generic copy and also to the orginal tree. procedure Process_Compilation_Unit_Pragmas (N : Node_Id); -- Called at the start of processing compilation unit N to deal with any -- special issues regarding pragmas. In particular, we have to deal with -- Suppress_All at this stage, since it can appear after the unit instead -- of before (actually we allow it to appear anywhere). procedure Relocate_Pragmas_To_Body (Subp_Body : Node_Id; Target_Body : Node_Id := Empty); -- Resocate all pragmas that follow and apply to subprogram body Subp_Body -- to its own declaration list. Candidate pragmas are classified in table -- Pragma_On_Body_Or_Stub_OK. If Target_Body is set, the pragma are moved -- to the declarations of Target_Body. This formal should be set when -- dealing with subprogram body stubs or expression functions. procedure Set_Encoded_Interface_Name (E : Entity_Id; S : Node_Id); -- This routine is used to set an encoded interface name. The node S is -- an N_String_Literal node for the external name to be set, and E is an -- entity whose Interface_Name field is to be set. In the normal case where -- S contains a name that is a valid C identifier, then S is simply set as -- the value of the Interface_Name. Otherwise it is encoded as needed by -- particular operating systems. See the body for details of the encoding. end Sem_Prag;