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) 1992-2018, 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 emulate an Ada 2012 aspect 37 38 Aspect_Specifying_Pragma : constant array (Pragma_Id) of Boolean := 39 (Pragma_Abstract_State => True, 40 Pragma_All_Calls_Remote => True, 41 Pragma_Annotate => True, 42 Pragma_Async_Readers => True, 43 Pragma_Async_Writers => True, 44 Pragma_Asynchronous => True, 45 Pragma_Atomic => True, 46 Pragma_Atomic_Components => True, 47 Pragma_Attach_Handler => True, 48 Pragma_Constant_After_Elaboration => True, 49 Pragma_Contract_Cases => True, 50 Pragma_Convention => True, 51 Pragma_CPU => True, 52 Pragma_Default_Initial_Condition => True, 53 Pragma_Default_Storage_Pool => True, 54 Pragma_Depends => True, 55 Pragma_Discard_Names => True, 56 Pragma_Dispatching_Domain => True, 57 Pragma_Effective_Reads => True, 58 Pragma_Effective_Writes => True, 59 Pragma_Elaborate_Body => True, 60 Pragma_Export => True, 61 Pragma_Extensions_Visible => True, 62 Pragma_Favor_Top_Level => True, 63 Pragma_Ghost => True, 64 Pragma_Global => True, 65 Pragma_Import => True, 66 Pragma_Independent => True, 67 Pragma_Independent_Components => True, 68 Pragma_Initial_Condition => True, 69 Pragma_Initializes => True, 70 Pragma_Inline => True, 71 Pragma_Inline_Always => True, 72 Pragma_Interrupt_Handler => True, 73 Pragma_Interrupt_Priority => True, 74 Pragma_Invariant => True, 75 Pragma_Linker_Section => True, 76 Pragma_Lock_Free => True, 77 Pragma_No_Elaboration_Code_All => True, 78 Pragma_No_Return => True, 79 Pragma_Obsolescent => True, 80 Pragma_Pack => True, 81 Pragma_Part_Of => True, 82 Pragma_Persistent_BSS => True, 83 Pragma_Post => True, 84 Pragma_Post_Class => True, 85 Pragma_Postcondition => True, 86 Pragma_Pre => True, 87 Pragma_Pre_Class => True, 88 Pragma_Precondition => True, 89 Pragma_Predicate => True, 90 Pragma_Preelaborable_Initialization => True, 91 Pragma_Preelaborate => True, 92 Pragma_Priority => True, 93 Pragma_Pure => True, 94 Pragma_Pure_Function => True, 95 Pragma_Refined_Depends => True, 96 Pragma_Refined_Global => True, 97 Pragma_Refined_Post => True, 98 Pragma_Refined_State => True, 99 Pragma_Relative_Deadline => True, 100 Pragma_Remote_Access_Type => True, 101 Pragma_Remote_Call_Interface => True, 102 Pragma_Remote_Types => True, 103 Pragma_Secondary_Stack_Size => True, 104 Pragma_Shared => True, 105 Pragma_Shared_Passive => True, 106 Pragma_Simple_Storage_Pool_Type => True, 107 Pragma_SPARK_Mode => True, 108 Pragma_Storage_Size => True, 109 Pragma_Suppress => True, 110 Pragma_Suppress_Debug_Info => True, 111 Pragma_Suppress_Initialization => True, 112 Pragma_Test_Case => True, 113 Pragma_Thread_Local_Storage => True, 114 Pragma_Type_Invariant => True, 115 Pragma_Unchecked_Union => True, 116 Pragma_Universal_Aliasing => True, 117 Pragma_Universal_Data => True, 118 Pragma_Unmodified => True, 119 Pragma_Unreferenced => True, 120 Pragma_Unreferenced_Objects => True, 121 Pragma_Unsuppress => True, 122 Pragma_Volatile => True, 123 Pragma_Volatile_Components => True, 124 Pragma_Volatile_Full_Access => True, 125 Pragma_Warnings => True, 126 others => False); 127 128 -- The following table lists all pragmas that act as an assertion 129 -- expression. 130 131 Assertion_Expression_Pragma : constant array (Pragma_Id) of Boolean := 132 (Pragma_Assert => True, 133 Pragma_Assert_And_Cut => True, 134 Pragma_Assume => True, 135 Pragma_Check => True, 136 Pragma_Contract_Cases => True, 137 Pragma_Default_Initial_Condition => True, 138 Pragma_Initial_Condition => True, 139 Pragma_Invariant => True, 140 Pragma_Loop_Invariant => True, 141 Pragma_Loop_Variant => True, 142 Pragma_Post => True, 143 Pragma_Post_Class => True, 144 Pragma_Postcondition => True, 145 Pragma_Pre => True, 146 Pragma_Pre_Class => True, 147 Pragma_Precondition => True, 148 Pragma_Predicate => True, 149 Pragma_Refined_Post => True, 150 Pragma_Test_Case => True, 151 Pragma_Type_Invariant => True, 152 Pragma_Type_Invariant_Class => True, 153 others => False); 154 155 -- The following table lists all the implementation-defined pragmas that 156 -- should apply to the anonymous object produced by the analysis of a 157 -- single protected or task type. The table should be synchronized with 158 -- Aspect_On_Anonymous_Object_OK in unit Aspects. 159 160 Pragma_On_Anonymous_Object_OK : constant array (Pragma_Id) of Boolean := 161 (Pragma_Depends => True, 162 Pragma_Global => True, 163 Pragma_Part_Of => True, 164 others => False); 165 166 -- The following table lists all the implementation-defined pragmas that 167 -- may apply to a body stub (no language defined pragmas apply). The table 168 -- should be synchronized with Aspect_On_Body_Or_Stub_OK in unit Aspects. 169 170 Pragma_On_Body_Or_Stub_OK : constant array (Pragma_Id) of Boolean := 171 (Pragma_Refined_Depends => True, 172 Pragma_Refined_Global => True, 173 Pragma_Refined_Post => True, 174 Pragma_SPARK_Mode => True, 175 Pragma_Warnings => True, 176 others => False); 177 178 -- The following table lists all pragmas which are significant in SPARK and 179 -- as a result get translated into verification conditions. The table is an 180 -- amalgamation of the pragmas listed in SPARK RM 16.1 and internally added 181 -- entries. 182 183 Pragma_Significant_In_SPARK : constant array (Pragma_Id) of Boolean := 184 (Pragma_All_Calls_Remote => False, 185 Pragma_Asynchronous => False, 186 Pragma_Default_Storage_Pool => False, 187 Pragma_Discard_Names => False, 188 Pragma_Dispatching_Domain => False, 189 Pragma_Priority_Specific_Dispatching => False, 190 Pragma_Remote_Call_Interface => False, 191 Pragma_Remote_Types => False, 192 Pragma_Shared_Passive => False, 193 Pragma_Task_Dispatching_Policy => False, 194 Pragma_Unmodified => False, 195 Pragma_Unreferenced => False, 196 Pragma_Warnings => False, 197 others => True); 198 199 ----------------- 200 -- Subprograms -- 201 ----------------- 202 203 procedure Analyze_Pragma (N : Node_Id); 204 -- Analyze procedure for pragma reference node N 205 206 procedure Analyze_Contract_Cases_In_Decl_Part 207 (N : Node_Id; 208 Freeze_Id : Entity_Id := Empty); 209 -- Perform full analysis of delayed pragma Contract_Cases. Freeze_Id is the 210 -- entity of [generic] package body or [generic] subprogram body which 211 -- caused "freezing" of the related contract where the pragma resides. 212 213 procedure Analyze_Depends_In_Decl_Part (N : Node_Id); 214 -- Perform full analysis of delayed pragma Depends. This routine is also 215 -- capable of performing basic analysis of pragma Refined_Depends. 216 217 procedure Analyze_External_Property_In_Decl_Part 218 (N : Node_Id; 219 Expr_Val : out Boolean); 220 -- Perform full analysis of delayed pragmas Async_Readers, Async_Writers, 221 -- Effective_Reads and Effective_Writes. Flag Expr_Val contains the Boolean 222 -- argument of the pragma or a default True if no argument is present. 223 224 procedure Analyze_Global_In_Decl_Part (N : Node_Id); 225 -- Perform full analysis of delayed pragma Global. This routine is also 226 -- capable of performing basic analysis of pragma Refined_Global. 227 228 procedure Analyze_Initial_Condition_In_Decl_Part (N : Node_Id); 229 -- Perform full analysis of delayed pragma Initial_Condition 230 231 procedure Analyze_Initializes_In_Decl_Part (N : Node_Id); 232 -- Perform full analysis of delayed pragma Initializes 233 234 procedure Analyze_Part_Of_In_Decl_Part 235 (N : Node_Id; 236 Freeze_Id : Entity_Id := Empty); 237 -- Perform full analysis of delayed pragma Part_Of. Freeze_Id is the entity 238 -- of [generic] package body or [generic] subprogram body which caused the 239 -- "freezing" of the related contract where the pragma resides. 240 241 procedure Analyze_Pre_Post_Condition_In_Decl_Part 242 (N : Node_Id; 243 Freeze_Id : Entity_Id := Empty); 244 -- Perform full analysis of pragmas Precondition and Postcondition. 245 -- Freeze_Id denotes the entity of [generic] package body or [generic] 246 -- subprogram body which caused "freezing" of the related contract where 247 -- the pragma resides. 248 249 procedure Analyze_Refined_Depends_In_Decl_Part (N : Node_Id); 250 -- Preform full analysis of delayed pragma Refined_Depends. This routine 251 -- uses Analyze_Depends_In_Decl_Part as a starting point, then performs 252 -- various consistency checks between Depends and Refined_Depends. 253 254 procedure Analyze_Refined_Global_In_Decl_Part (N : Node_Id); 255 -- Perform full analysis of delayed pragma Refined_Global. This routine 256 -- uses Analyze_Global_In_Decl_Part as a starting point, then performs 257 -- various consistency checks between Global and Refined_Global. 258 259 procedure Analyze_Refined_State_In_Decl_Part 260 (N : Node_Id; 261 Freeze_Id : Entity_Id := Empty); 262 -- Perform full analysis of delayed pragma Refined_State. Freeze_Id denotes 263 -- the entity of [generic] package body or [generic] subprogram body which 264 -- caused "freezing" of the related contract where the pragma resides. 265 266 procedure Analyze_Test_Case_In_Decl_Part (N : Node_Id); 267 -- Perform preanalysis of pragma Test_Case 268 269 function Build_Pragma_Check_Equivalent 270 (Prag : Node_Id; 271 Subp_Id : Entity_Id := Empty; 272 Inher_Id : Entity_Id := Empty; 273 Keep_Pragma_Id : Boolean := False) return Node_Id; 274 -- Transform a pre- or [refined] postcondition denoted by Prag into an 275 -- equivalent pragma Check. When the pre- or postcondition is inherited, 276 -- the routine replaces the references of all formals of Inher_Id 277 -- and primitive operations of its controlling type by references 278 -- to the corresponding entities of Subp_Id and the descendant type. 279 -- Keep_Pragma_Id is True when the newly created pragma should be 280 -- in fact of the same kind as the source pragma Prag. This is used 281 -- in GNATprove_Mode to generate the inherited pre- and postconditions. 282 283 procedure Check_Applicable_Policy (N : Node_Id); 284 -- N is either an N_Aspect or an N_Pragma node. There are two cases. If 285 -- the name of the aspect or pragma is not one of those recognized as 286 -- an assertion kind by an Assertion_Policy pragma, then the call has 287 -- no effect. Note that in the case of a pragma derived from an aspect, 288 -- the name we use for the purpose of this procedure is the aspect name, 289 -- which may be different from the pragma name (e.g. Precondition for 290 -- Pre aspect). In addition, 'Class aspects are recognized (and the 291 -- corresponding special names used in the processing). 292 -- 293 -- If the name is a valid assertion kind name, then the Check_Policy pragma 294 -- chain is checked for a matching entry (or for an Assertion entry which 295 -- matches all possibilities). If a matching entry is found then the policy 296 -- is checked. If it is On or Check, then the Is_Checked flag is set in 297 -- the aspect or pragma node. If it is Off, Ignore, or Disable, then the 298 -- Is_Ignored flag is set in the aspect or pragma node. Additionally for 299 -- policy Disable, the Is_Disabled flag is set. 300 -- 301 -- If no matching Check_Policy pragma is found then the effect depends on 302 -- whether -gnata was used, if so, then the call has no effect, otherwise 303 -- Is_Ignored (but not Is_Disabled) is set True. 304 305 procedure Check_External_Properties 306 (Item : Node_Id; 307 AR : Boolean; 308 AW : Boolean; 309 ER : Boolean; 310 EW : Boolean); 311 -- Flags AR, AW, ER and EW denote the static values of external properties 312 -- Async_Readers, Async_Writers, Effective_Reads and Effective_Writes. Item 313 -- is the related variable or state. Ensure legality of the combination and 314 -- issue an error for an illegal combination. 315 316 function Check_Kind (Nam : Name_Id) return Name_Id; 317 -- This function is used in connection with pragmas Assert, Check, 318 -- and assertion aspects and pragmas, to determine if Check pragmas 319 -- (or corresponding assertion aspects or pragmas) are currently active 320 -- as determined by the presence of -gnata on the command line (which 321 -- sets the default), and the appearance of pragmas Check_Policy and 322 -- Assertion_Policy as configuration pragmas either in a configuration 323 -- pragma file, or at the start of the current unit, or locally given 324 -- Check_Policy and Assertion_Policy pragmas that are currently active. 325 -- 326 -- The value returned is one of the names Check, Ignore, Disable (On 327 -- returns Check, and Off returns Ignore). 328 -- 329 -- Note: for assertion kinds Pre'Class, Post'Class, Invariant'Class, 330 -- and Type_Invariant'Class, the name passed is Name_uPre, Name_uPost, 331 -- Name_uInvariant, or Name_uType_Invariant, which corresponds to _Pre, 332 -- _Post, _Invariant, or _Type_Invariant, which are special names used 333 -- in identifiers to represent these attribute references. 334 335 procedure Check_Missing_Part_Of (Item_Id : Entity_Id); 336 -- Determine whether the placement within the state space of an abstract 337 -- state, variable or package instantiation denoted by Item_Id requires the 338 -- use of indicator/option Part_Of. If this is the case, emit an error. 339 340 procedure Collect_Inherited_Class_Wide_Conditions (Subp : Entity_Id); 341 -- In GNATprove mode, when analyzing an overriding subprogram, check 342 -- whether the overridden operations have class-wide pre/postconditions, 343 -- and generate the corresponding pragmas. The pragmas are inserted after 344 -- the subprogram declaration, together with those generated for other 345 -- aspects of the subprogram. 346 347 procedure Collect_Subprogram_Inputs_Outputs 348 (Subp_Id : Entity_Id; 349 Synthesize : Boolean := False; 350 Subp_Inputs : in out Elist_Id; 351 Subp_Outputs : in out Elist_Id; 352 Global_Seen : out Boolean); 353 -- Subsidiary to the analysis of pragmas Depends, Global, Refined_Depends 354 -- and Refined_Global. The routine is also used by GNATprove. Collect all 355 -- inputs and outputs of subprogram Subp_Id in lists Subp_Inputs (inputs) 356 -- and Subp_Outputs (outputs). The inputs and outputs are gathered from: 357 -- 1) The formal parameters of the subprogram 358 -- 2) The generic formal parameters of the generic subprogram 359 -- 3) The current instance of a concurrent type 360 -- 4) The items of pragma [Refined_]Global 361 -- or 362 -- 5) The items of pragma [Refined_]Depends if there is no pragma 363 -- [Refined_]Global present and flag Synthesize is set to True. 364 -- If the subprogram has no inputs and/or outputs, then the returned list 365 -- is No_Elist. Flag Global_Seen is set when the related subprogram has 366 -- pragma [Refined_]Global. 367 368 function Delay_Config_Pragma_Analyze (N : Node_Id) return Boolean; 369 -- N is a pragma appearing in a configuration pragma file. Most such 370 -- pragmas are analyzed when the file is read, before parsing and analyzing 371 -- the main unit. However, the analysis of certain pragmas results in 372 -- adding information to the compiled main unit, and this cannot be done 373 -- till the main unit is processed. Such pragmas return True from this 374 -- function and in Frontend pragmas where Delay_Config_Pragma_Analyze is 375 -- True have their analysis delayed until after the main program is parsed 376 -- and analyzed. 377 378 function Find_Related_Package_Or_Body 379 (Prag : Node_Id; 380 Do_Checks : Boolean := False) return Node_Id; 381 -- Subsidiary to the analysis of pragmas 382 -- Abstract_State 383 -- Initial_Condition 384 -- Initializes 385 -- Refined_State 386 -- Find the declaration of the related package [body] subject to pragma 387 -- Prag. The return value is either N_Package_Declaration, N_Package_Body, 388 -- or Empty if the placement of the pragma is illegal. If flag Do_Checks is 389 -- set, the routine reports duplicate pragmas. 390 391 function Find_Related_Declaration_Or_Body 392 (Prag : Node_Id; 393 Do_Checks : Boolean := False) return Node_Id; 394 -- Subsidiary to the analysis of pragmas 395 -- Contract_Cases 396 -- Depends 397 -- Extensions_Visible 398 -- Global 399 -- Initializes 400 -- Max_Queue_Length 401 -- Post 402 -- Post_Class 403 -- Postcondition 404 -- Pre 405 -- Pre_Class 406 -- Precondition 407 -- Refined_Depends 408 -- Refined_Global 409 -- Refined_Post 410 -- Refined_State 411 -- Test_Case 412 -- Volatile_Function 413 -- as well as attributes 'Old and 'Result. Find the declaration of the 414 -- related entry, subprogram or task type [body] subject to pragma Prag. 415 -- If flag Do_Checks is set, the routine reports duplicate pragmas and 416 -- detects improper use of refinement pragmas in stand alone expression 417 -- functions. 418 419 function Get_Argument 420 (Prag : Node_Id; 421 Context_Id : Node_Id := Empty) return Node_Id; 422 -- Obtain the argument of pragma Prag depending on context and the nature 423 -- of the pragma. The argument is extracted in the following manner: 424 -- 425 -- When the pragma is generated from an aspect, return the corresponding 426 -- aspect for ASIS or when Context_Id denotes a generic unit. 427 -- 428 -- Otherwise return the first argument of Prag 429 -- 430 -- Context denotes the entity of the function, package or procedure where 431 -- Prag resides. 432 433 function Get_SPARK_Mode_From_Annotation 434 (N : Node_Id) return SPARK_Mode_Type; 435 -- Given an aspect or pragma SPARK_Mode node, return corresponding mode id 436 437 procedure Initialize; 438 -- Initializes data structures used for pragma processing. Must be called 439 -- before analyzing each new main source program. 440 441 function Is_Config_Static_String (Arg : Node_Id) return Boolean; 442 -- This is called for a configuration pragma that requires either string 443 -- literal or a concatenation of string literals. We cannot use normal 444 -- static string processing because it is too early in the case of the 445 -- pragma appearing in a configuration pragmas file. If Arg is of an 446 -- appropriate form, then this call obtains the string (doing any necessary 447 -- concatenations) and places it in Name_Buffer, setting Name_Len to its 448 -- length, and then returns True. If it is not of the correct form, then an 449 -- appropriate error message is posted, and False is returned. 450 451 function Is_Elaboration_SPARK_Mode (N : Node_Id) return Boolean; 452 -- Determine whether pragma SPARK_Mode appears in the statement part of a 453 -- package body. 454 455 function Is_Enabled_Pragma (Prag : Node_Id) return Boolean; 456 -- Determine whether a Boolean-like SPARK pragma Prag is enabled. To be 457 -- considered enabled, the pragma must either: 458 -- * Appear without its Boolean expression 459 -- * The Boolean expression evaluates to "True" 460 -- 461 -- Boolean-like SPARK pragmas differ from pure Boolean Ada pragmas in that 462 -- their optional Boolean expression must be static and cannot benefit from 463 -- forward references. The following are Boolean-like SPARK pragmas: 464 -- Async_Readers 465 -- Async_Writers 466 -- Constant_After_Elaboration 467 -- Effective_Reads 468 -- Effective_Writes 469 -- Extensions_Visible 470 -- Volatile_Function 471 472 function Is_Non_Significant_Pragma_Reference (N : Node_Id) return Boolean; 473 -- The node N is a node for an entity and the issue is whether the 474 -- occurrence is a reference for the purposes of giving warnings about 475 -- unreferenced variables. This function returns True if the reference is 476 -- not a reference from this point of view (e.g. the occurrence in a pragma 477 -- Pack) and False if it is a real reference (e.g. the occurrence in a 478 -- pragma Export); 479 480 function Is_Pragma_String_Literal (Par : Node_Id) return Boolean; 481 -- Given an N_Pragma_Argument_Association node, Par, which has the form of 482 -- an operator symbol, determines whether or not it should be treated as an 483 -- string literal. This is called by Sem_Ch6.Analyze_Operator_Symbol. If 484 -- True is returned, the argument is converted to a string literal. If 485 -- False is returned, then the argument is treated as an entity reference 486 -- to the operator. 487 488 function Is_Private_SPARK_Mode (N : Node_Id) return Boolean; 489 -- Determine whether pragma SPARK_Mode appears in the private part of a 490 -- package. 491 492 function Is_Valid_Assertion_Kind (Nam : Name_Id) return Boolean; 493 -- Returns True if Nam is one of the names recognized as a valid assertion 494 -- kind by the Assertion_Policy pragma. Note that the 'Class cases are 495 -- represented by the corresponding special names Name_uPre, Name_uPost, 496 -- Name_uInvariant, and Name_uType_Invariant (_Pre, _Post, _Invariant, 497 -- and _Type_Invariant). 498 499 procedure Process_Compile_Time_Warning_Or_Error 500 (N : Node_Id; 501 Eloc : Source_Ptr); 502 -- Common processing for Compile_Time_Error and Compile_Time_Warning of 503 -- pragma N. Called when the pragma is processed as part of its regular 504 -- analysis but also called after calling the back end to validate these 505 -- pragmas for size and alignment appropriateness. 506 507 procedure Process_Compilation_Unit_Pragmas (N : Node_Id); 508 -- Called at the start of processing compilation unit N to deal with any 509 -- special issues regarding pragmas. In particular, we have to deal with 510 -- Suppress_All at this stage, since it can appear after the unit instead 511 -- of before (actually we allow it to appear anywhere). 512 513 procedure Relocate_Pragmas_To_Anonymous_Object 514 (Typ_Decl : Node_Id; 515 Obj_Decl : Node_Id); 516 -- Relocate all pragmas that appear in the visible declarations of task or 517 -- protected type declaration Typ_Decl after the declaration of anonymous 518 -- object Obj_Decl. Table Pragmas_On_Anonymous_Object_OK contains the list 519 -- of candidate pragmas. 520 521 procedure Relocate_Pragmas_To_Body 522 (Subp_Body : Node_Id; 523 Target_Body : Node_Id := Empty); 524 -- Resocate all pragmas that follow and apply to subprogram body Subp_Body 525 -- to its own declaration list. Candidate pragmas are classified in table 526 -- Pragma_On_Body_Or_Stub_OK. If Target_Body is set, the pragma are moved 527 -- to the declarations of Target_Body. This formal should be set when 528 -- dealing with subprogram body stubs or expression functions. 529 530 procedure Set_Encoded_Interface_Name (E : Entity_Id; S : Node_Id); 531 -- This routine is used to set an encoded interface name. The node S is 532 -- an N_String_Literal node for the external name to be set, and E is an 533 -- entity whose Interface_Name field is to be set. In the normal case where 534 -- S contains a name that is a valid C identifier, then S is simply set as 535 -- the value of the Interface_Name. Otherwise it is encoded as needed by 536 -- particular operating systems. See the body for details of the encoding. 537 538 function Test_Case_Arg 539 (Prag : Node_Id; 540 Arg_Nam : Name_Id; 541 From_Aspect : Boolean := False) return Node_Id; 542 -- Obtain argument "Name", "Mode", "Ensures" or "Requires" from Test_Case 543 -- pragma Prag as denoted by Arg_Nam. When From_Aspect is set, an attempt 544 -- is made to retrieve the argument from the corresponding aspect if there 545 -- is one. The returned argument has several formats: 546 -- 547 -- N_Pragma_Argument_Association if retrieved directly from the pragma 548 -- 549 -- N_Component_Association if retrieved from the corresponding aspect and 550 -- the argument appears in a named association form. 551 -- 552 -- An arbitrary expression if retrieved from the corresponding aspect and 553 -- the argument appears in positional form. 554 -- 555 -- Empty if there is no such argument 556 557end Sem_Prag; 558