1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- S E M _ P R A G -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2013, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- 17-- for more details. You should have received a copy of the GNU General -- 18-- Public License distributed with GNAT; see file COPYING3. If not, go to -- 19-- http://www.gnu.org/licenses for a complete copy of the license. -- 20-- -- 21-- GNAT was originally developed by the GNAT team at New York University. -- 22-- Extensive contributions were provided by Ada Core Technologies Inc. -- 23-- -- 24------------------------------------------------------------------------------ 25 26-- Pragma handling is isolated in a separate package 27-- (logically this processing belongs in chapter 4) 28 29with Namet; use Namet; 30with Opt; use Opt; 31with Snames; use Snames; 32with Types; use Types; 33 34package Sem_Prag is 35 36 -- The following table lists all pragmas that act as an assertion 37 -- expression. 38 39 Assertion_Expression_Pragma : constant array (Pragma_Id) of Boolean := 40 (Pragma_Assert => True, 41 Pragma_Assert_And_Cut => True, 42 Pragma_Assume => True, 43 Pragma_Check => True, 44 Pragma_Contract_Cases => True, 45 Pragma_Initial_Condition => True, 46 Pragma_Invariant => True, 47 Pragma_Loop_Invariant => True, 48 Pragma_Loop_Variant => True, 49 Pragma_Post => True, 50 Pragma_Post_Class => True, 51 Pragma_Postcondition => True, 52 Pragma_Pre => True, 53 Pragma_Pre_Class => True, 54 Pragma_Precondition => True, 55 Pragma_Predicate => True, 56 Pragma_Refined_Post => True, 57 Pragma_Test_Case => True, 58 Pragma_Type_Invariant => True, 59 Pragma_Type_Invariant_Class => True, 60 others => False); 61 62 -- The following table lists all the implementation-defined pragmas that 63 -- may apply to a body stub (no language defined pragmas apply). The table 64 -- should be synchronized with Aspect_On_Body_Or_Stub_OK in unit Aspects if 65 -- the pragmas below implement an aspect. 66 67 Pragma_On_Body_Or_Stub_OK : constant array (Pragma_Id) of Boolean := 68 (Pragma_Refined_Depends => True, 69 Pragma_Refined_Global => True, 70 Pragma_Refined_Post => True, 71 Pragma_SPARK_Mode => True, 72 Pragma_Warnings => True, 73 others => False); 74 75 ----------------- 76 -- Subprograms -- 77 ----------------- 78 79 procedure Analyze_Pragma (N : Node_Id); 80 -- Analyze procedure for pragma reference node N 81 82 procedure Analyze_Contract_Cases_In_Decl_Part (N : Node_Id); 83 -- Perform full analysis and expansion of delayed pragma Contract_Cases 84 85 procedure Analyze_Depends_In_Decl_Part (N : Node_Id); 86 -- Perform full analysis of delayed pragma Depends. This routine is also 87 -- capable of performing basic analysis of pragma Refined_Depends. 88 89 procedure Analyze_External_Property_In_Decl_Part 90 (N : Node_Id; 91 Expr_Val : out Boolean); 92 -- Perform full analysis of delayed pragmas Async_Readers, Async_Writers, 93 -- Effective_Reads and Effective_Writes. Flag Expr_Val contains the Boolean 94 -- argument of the pragma or a default True if no argument is present. 95 96 procedure Analyze_Global_In_Decl_Part (N : Node_Id); 97 -- Perform full analysis of delayed pragma Global. This routine is also 98 -- capable of performing basic analysis of pragma Refind_Global. 99 100 procedure Analyze_Initial_Condition_In_Decl_Part (N : Node_Id); 101 -- Perform full analysis of delayed pragma Initial_Condition 102 103 procedure Analyze_Initializes_In_Decl_Part (N : Node_Id); 104 -- Perform full analysis of delayed pragma Initializes 105 106 procedure Analyze_Pre_Post_Condition_In_Decl_Part 107 (Prag : Node_Id; 108 Subp_Id : Entity_Id); 109 -- Perform preanalysis of a [refined] precondition or postcondition that 110 -- appears on a subprogram declaration or body [stub]. Prag denotes the 111 -- pragma, Subp_Id is the entity of the related subprogram. The preanalysis 112 -- of the expression is done as "spec expression" (see section "Handling 113 -- of Default and Per-Object Expressions in Sem). 114 115 procedure Analyze_Refined_Depends_In_Decl_Part (N : Node_Id); 116 -- Preform full analysis of delayed pragma Refined_Depends. This routine 117 -- uses Analyze_Depends_In_Decl_Part as a starting point, then performs 118 -- various consistency checks between Depends and Refined_Depends. 119 120 procedure Analyze_Refined_Global_In_Decl_Part (N : Node_Id); 121 -- Perform full analysis of delayed pragma Refined_Global. This routine 122 -- uses Analyze_Global_In_Decl_Part as a starting point, then performs 123 -- various consistency checks between Global and Refined_Global. 124 125 procedure Analyze_Refined_State_In_Decl_Part (N : Node_Id); 126 -- Perform full analysis of delayed pragma Refined_State 127 128 procedure Analyze_Test_Case_In_Decl_Part (N : Node_Id; S : Entity_Id); 129 -- Perform preanalysis of pragma Test_Case that applies to a subprogram 130 -- declaration. Parameter N denotes the pragma, S is the entity of the 131 -- related subprogram. The preanalysis of the expression is done as "spec 132 -- expression" (see section "Handling of Default and Per-Object Expressions 133 -- in Sem). 134 135 procedure Check_Applicable_Policy (N : Node_Id); 136 -- N is either an N_Aspect or an N_Pragma node. There are two cases. If 137 -- the name of the aspect or pragma is not one of those recognized as 138 -- an assertion kind by an Assertion_Policy pragma, then the call has 139 -- no effect. Note that in the case of a pragma derived from an aspect, 140 -- the name we use for the purpose of this procedure is the aspect name, 141 -- which may be different from the pragma name (e.g. Precondition for 142 -- Pre aspect). In addition, 'Class aspects are recognized (and the 143 -- corresponding special names used in the processing). 144 -- 145 -- If the name is a valid assertion kind name, then the Check_Policy pragma 146 -- chain is checked for a matching entry (or for an Assertion entry which 147 -- matches all possibilities). If a matching entry is found then the policy 148 -- is checked. If it is On or Check, then the Is_Checked flag is set in 149 -- the aspect or pragma node. If it is Off, Ignore, or Disable, then the 150 -- Is_Ignored flag is set in the aspect or pragma node. Additionally for 151 -- policy Disable, the Is_Disabled flag is set. 152 -- 153 -- If no matching Check_Policy pragma is found then the effect depends on 154 -- whether -gnata was used, if so, then the call has no effect, otherwise 155 -- Is_Ignored (but not Is_Disabled) is set True. 156 157 procedure Check_External_Properties 158 (Item : Node_Id; 159 AR : Boolean; 160 AW : Boolean; 161 ER : Boolean; 162 EW : Boolean); 163 -- Flags AR, AW, ER and EW denote the static values of external properties 164 -- Async_Readers, Async_Writers, Effective_Reads and Effective_Writes. Item 165 -- is the related variable or state. Ensure legality of the combination and 166 -- issue an error for an illegal combination. 167 168 procedure Check_Missing_Part_Of (Item_Id : Entity_Id); 169 -- Determine whether the placement within the state space of an abstract 170 -- state, variable or package instantiation denoted by Item_Id requires the 171 -- use of indicator/option Part_Of. If this is the case, emit an error. 172 173 function Delay_Config_Pragma_Analyze (N : Node_Id) return Boolean; 174 -- N is a pragma appearing in a configuration pragma file. Most such 175 -- pragmas are analyzed when the file is read, before parsing and analyzing 176 -- the main unit. However, the analysis of certain pragmas results in 177 -- adding information to the compiled main unit, and this cannot be done 178 -- till the main unit is processed. Such pragmas return True from this 179 -- function and in Frontend pragmas where Delay_Config_Pragma_Analyze is 180 -- True have their analysis delayed until after the main program is parsed 181 -- and analyzed. 182 183 function Get_SPARK_Mode_From_Pragma (N : Node_Id) return SPARK_Mode_Type; 184 -- Given a pragma SPARK_Mode node, return corresponding mode id 185 186 procedure Initialize; 187 -- Initializes data structures used for pragma processing. Must be called 188 -- before analyzing each new main source program. 189 190 function Is_Config_Static_String (Arg : Node_Id) return Boolean; 191 -- This is called for a configuration pragma that requires either string 192 -- literal or a concatenation of string literals. We cannot use normal 193 -- static string processing because it is too early in the case of the 194 -- pragma appearing in a configuration pragmas file. If Arg is of an 195 -- appropriate form, then this call obtains the string (doing any necessary 196 -- concatenations) and places it in Name_Buffer, setting Name_Len to its 197 -- length, and then returns True. If it is not of the correct form, then an 198 -- appropriate error message is posted, and False is returned. 199 200 function Is_Elaboration_SPARK_Mode (N : Node_Id) return Boolean; 201 -- Determine whether pragma SPARK_Mode appears in the statement part of a 202 -- package body. 203 204 function Is_Non_Significant_Pragma_Reference (N : Node_Id) return Boolean; 205 -- The node N is a node for an entity and the issue is whether the 206 -- occurrence is a reference for the purposes of giving warnings about 207 -- unreferenced variables. This function returns True if the reference is 208 -- not a reference from this point of view (e.g. the occurrence in a pragma 209 -- Pack) and False if it is a real reference (e.g. the occurrence in a 210 -- pragma Export); 211 212 function Is_Pragma_String_Literal (Par : Node_Id) return Boolean; 213 -- Given an N_Pragma_Argument_Association node, Par, which has the form of 214 -- an operator symbol, determines whether or not it should be treated as an 215 -- string literal. This is called by Sem_Ch6.Analyze_Operator_Symbol. If 216 -- True is returned, the argument is converted to a string literal. If 217 -- False is returned, then the argument is treated as an entity reference 218 -- to the operator. 219 220 function Is_Private_SPARK_Mode (N : Node_Id) return Boolean; 221 -- Determine whether pragma SPARK_Mode appears in the private part of a 222 -- package. 223 224 function Is_Valid_Assertion_Kind (Nam : Name_Id) return Boolean; 225 -- Returns True if Nam is one of the names recognized as a valid assertion 226 -- kind by the Assertion_Policy pragma. Note that the 'Class cases are 227 -- represented by the corresponding special names Name_uPre, Name_uPost, 228 -- Name_uInviarnat, and Name_uType_Invariant (_Pre, _Post, _Invariant, 229 -- and _Type_Invariant). 230 231 procedure Make_Aspect_For_PPC_In_Gen_Sub_Decl (Decl : Node_Id); 232 -- This routine makes aspects from precondition or postcondition pragmas 233 -- that appear within a generic subprogram declaration. Decl is the generic 234 -- subprogram declaration node. Note that the aspects are attached to the 235 -- generic copy and also to the orginal tree. 236 237 procedure Process_Compilation_Unit_Pragmas (N : Node_Id); 238 -- Called at the start of processing compilation unit N to deal with any 239 -- special issues regarding pragmas. In particular, we have to deal with 240 -- Suppress_All at this stage, since it can appear after the unit instead 241 -- of before (actually we allow it to appear anywhere). 242 243 procedure Relocate_Pragmas_To_Body 244 (Subp_Body : Node_Id; 245 Target_Body : Node_Id := Empty); 246 -- Resocate all pragmas that follow and apply to subprogram body Subp_Body 247 -- to its own declaration list. Candidate pragmas are classified in table 248 -- Pragma_On_Body_Or_Stub_OK. If Target_Body is set, the pragma are moved 249 -- to the declarations of Target_Body. This formal should be set when 250 -- dealing with subprogram body stubs or expression functions. 251 252 procedure Set_Encoded_Interface_Name (E : Entity_Id; S : Node_Id); 253 -- This routine is used to set an encoded interface name. The node S is an 254 -- N_String_Literal node for the external name to be set, and E is an 255 -- entity whose Interface_Name field is to be set. In the normal case where 256 -- S contains a name that is a valid C identifier, then S is simply set as 257 -- the value of the Interface_Name. Otherwise it is encoded. See the body 258 -- for details of the encoding. This encoding is only done on VMS systems, 259 -- since it seems pretty silly, but is needed to pass some dubious tests in 260 -- the test suite. 261 262end Sem_Prag; 263