gcc/ada/impunit.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              I M P U N I T                               --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --           Copyright (C) 2000-2012, 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 with Atree;    use Atree;
  27 with Errout;   use Errout;
  28 with Sinfo;    use Sinfo;
  29 with Fname.UF; use Fname.UF;
  30 with Lib;      use Lib;
  31 with Namet;    use Namet;
  32 with Opt;      use Opt;
  33 with Uname;    use Uname;
  34
  35 --  Note: this package body is used by GPS and GNATBench to supply a list of
  36 --  entries for help on available library routines.
  37
  38 package body Impunit is
  39
  40    subtype File_Name_8 is String (1 .. 8);
  41
  42    type File_Name_Record is record
  43       Fname : File_Name_8;
  44       --  8 character name of unit
  45
  46       RMdef : Boolean;
  47       --  True if unit is RM defined. False for any unit that is implementation
  48       --  defined (and thus not with'able in No_Implementation_Units mode).
  49    end record;
  50
  51    type File_List is array (Nat range <>) of File_Name_Record;
  52
  53    T : constant Boolean := True;
  54    F : constant Boolean := False;
  55    --  Short hand for RM_Defined values in lists below
  56
  57    ------------------
  58    -- Ada 95 Units --
  59    ------------------
  60
  61    --  The following is a giant string list containing the names of all non-
  62    --  implementation internal files, i.e. the complete list of files for
  63    --  internal units which a program may legitimately WITH when operating in
  64    --  either Ada 95 or Ada 2005 mode.
  65
  66    --  Note that this list should match the list of units documented in the
  67    --  "GNAT Library" section of the GNAT Reference Manual. A unit listed here
  68    --  must either be documented in that section or described in the Ada RM.
  69
  70    Non_Imp_File_Names_95 : constant File_List := (
  71
  72    ------------------------------------------------------
  73    -- Ada Hierarchy Units from Ada-95 Reference Manual --
  74    ------------------------------------------------------
  75
  76     ("a-astaco", T),  -- Ada.Asynchronous_Task_Control
  77     ("a-calend", T),  -- Ada.Calendar
  78     ("a-chahan", T),  -- Ada.Characters.Handling
  79     ("a-charac", T),  -- Ada.Characters
  80     ("a-chlat1", T),  -- Ada.Characters.Latin_1
  81     ("a-comlin", T),  -- Ada.Command_Line
  82     ("a-decima", T),  -- Ada.Decimal
  83     ("a-direio", T),  -- Ada.Direct_IO
  84     ("a-dynpri", T),  -- Ada.Dynamic_Priorities
  85     ("a-except", T),  -- Ada.Exceptions
  86     ("a-finali", T),  -- Ada.Finalization
  87     ("a-flteio", T),  -- Ada.Float_Text_IO
  88     ("a-fwteio", T),  -- Ada.Float_Wide_Text_IO
  89     ("a-inteio", T),  -- Ada.Integer_Text_IO
  90     ("a-interr", T),  -- Ada.Interrupts
  91     ("a-intnam", T),  -- Ada.Interrupts.Names
  92     ("a-ioexce", T),  -- Ada.IO_Exceptions
  93     ("a-iwteio", T),  -- Ada.Integer_Wide_Text_IO
  94     ("a-ncelfu", T),  -- Ada.Numerics.Complex_Elementary_Functions
  95     ("a-ngcefu", T),  -- Ada.Numerics.Generic_Complex_Elementary_Functions
  96     ("a-ngcoty", T),  -- Ada.Numerics.Generic_Complex_Types
  97     ("a-ngelfu", T),  -- Ada.Numerics.Generic_Elementary_Functions
  98     ("a-nucoty", T),  -- Ada.Numerics.Complex_Types
  99     ("a-nudira", T),  -- Ada.Numerics.Discrete_Random
 100     ("a-nuelfu", T),  -- Ada.Numerics.Elementary_Functions
 101     ("a-nuflra", T),  -- Ada.Numerics.Float_Random
 102     ("a-numeri", T),  -- Ada.Numerics
 103     ("a-reatim", T),  -- Ada.Real_Time
 104     ("a-sequio", T),  -- Ada.Sequential_IO
 105     ("a-stmaco", T),  -- Ada.Strings.Maps.Constants
 106     ("a-storio", T),  -- Ada.Storage_IO
 107     ("a-strbou", T),  -- Ada.Strings.Bounded
 108     ("a-stream", T),  -- Ada.Streams
 109     ("a-strfix", T),  -- Ada.Strings.Fixed
 110     ("a-string", T),  -- Ada.Strings
 111     ("a-strmap", T),  -- Ada.Strings.Maps
 112     ("a-strunb", T),  -- Ada.Strings.Unbounded
 113     ("a-ststio", T),  -- Ada.Streams.Stream_IO
 114     ("a-stwibo", T),  -- Ada.Strings.Wide_Bounded
 115     ("a-stwifi", T),  -- Ada.Strings.Wide_Fixed
 116     ("a-stwima", T),  -- Ada.Strings.Wide_Maps
 117     ("a-stwiun", T),  -- Ada.Strings.Wide_Unbounded
 118     ("a-swmwco", T),  -- Ada.Strings.Wide_Maps.Wide_Constants
 119     ("a-sytaco", T),  -- Ada.Synchronous_Task_Control
 120     ("a-tags  ", T),  -- Ada.Tags
 121     ("a-tasatt", T),  -- Ada.Task_Attributes
 122     ("a-taside", T),  -- Ada.Task_Identification
 123     ("a-teioed", T),  -- Ada.Text_IO.Editing
 124     ("a-textio", T),  -- Ada.Text_IO
 125     ("a-ticoio", T),  -- Ada.Text_IO.Complex_IO
 126     ("a-titest", T),  -- Ada.Text_IO.Text_Streams
 127     ("a-unccon", T),  -- Ada.Unchecked_Conversion
 128     ("a-uncdea", T),  -- Ada.Unchecked_Deallocation
 129     ("a-witeio", T),  -- Ada.Wide_Text_IO
 130     ("a-wtcoio", T),  -- Ada.Wide_Text_IO.Complex_IO
 131     ("a-wtedit", T),  -- Ada.Wide_Text_IO.Editing
 132     ("a-wttest", T),  -- Ada.Wide_Text_IO.Text_Streams
 133
 134    -------------------------------------------------
 135    -- RM Required Additions to Ada for GNAT Types --
 136    -------------------------------------------------
 137
 138    --  Note: Long versions are considered RM defined, but not the Long Long,
 139    --  Short, or Short_Short versions.
 140
 141     ("a-lfteio", T),  -- Ada.Long_Float_Text_IO
 142     ("a-lfwtio", T),  -- Ada.Long_Float_Wide_Text_IO
 143     ("a-liteio", T),  -- Ada.Long_Integer_Text_IO
 144     ("a-liwtio", T),  -- Ada.Long_Integer_Wide_Text_IO
 145     ("a-llftio", T),  -- Ada.Long_Long_Float_Text_IO
 146     ("a-llfwti", T),  -- Ada.Long_Long_Float_Wide_Text_IO
 147     ("a-llitio", T),  -- Ada.Long_Long_Integer_Text_IO
 148     ("a-lliwti", F),  -- Ada.Long_Long_Integer_Wide_Text_IO
 149     ("a-nlcefu", F),  -- Ada.Long_Complex_Elementary_Functions
 150     ("a-nlcoty", T),  -- Ada.Numerics.Long_Complex_Types
 151     ("a-nlelfu", T),  -- Ada.Numerics.Long_Elementary_Functions
 152     ("a-nllcef", F),  -- Ada.Long_Long_Complex_Elementary_Functions
 153     ("a-nllefu", F),  -- Ada.Numerics.Long_Long_Elementary_Functions
 154     ("a-nllcty", F),  -- Ada.Numerics.Long_Long_Complex_Types
 155     ("a-nscefu", F),  -- Ada.Short_Complex_Elementary_Functions
 156     ("a-nscoty", F),  -- Ada.Numerics.Short_Complex_Types
 157     ("a-nselfu", F),  -- Ada.Numerics.Short_Elementary_Functions
 158     ("a-sfteio", F),  -- Ada.Short_Float_Text_IO
 159     ("a-sfwtio", F),  -- Ada.Short_Float_Wide_Text_IO
 160     ("a-siteio", F),  -- Ada.Short_Integer_Text_IO
 161     ("a-siwtio", F),  -- Ada.Short_Integer_Wide_Text_IO
 162     ("a-ssitio", F),  -- Ada.Short_Short_Integer_Text_IO
 163     ("a-ssiwti", F),  -- Ada.Short_Short_Integer_Wide_Text_IO
 164
 165    -----------------------------------
 166    -- GNAT Defined Additions to Ada --
 167    -----------------------------------
 168
 169     ("a-calcon", F),  -- Ada.Calendar.Conversions
 170     ("a-chlat9", F),  -- Ada.Characters.Latin_9
 171     ("a-clrefi", F),  -- Ada.Command_Line.Response_File
 172     ("a-colien", F),  -- Ada.Command_Line.Environment
 173     ("a-colire", F),  -- Ada.Command_Line.Remove
 174     ("a-cwila1", F),  -- Ada.Characters.Wide_Latin_1
 175     ("a-cwila9", F),  -- Ada.Characters.Wide_Latin_9
 176     ("a-diocst", F),  -- Ada.Direct_IO.C_Streams
 177     ("a-einuoc", F),  -- Ada.Exceptions.Is_Null_Occurrence
 178     ("a-elchha", F),  -- Ada.Exceptions.Last_Chance_Handler
 179     ("a-exctra", F),  -- Ada.Exceptions.Traceback
 180     ("a-siocst", F),  -- Ada.Sequential_IO.C_Streams
 181     ("a-ssicst", F),  -- Ada.Streams.Stream_IO.C_Streams
 182     ("a-suteio", F),  -- Ada.Strings.Unbounded.Text_IO
 183     ("a-swuwti", F),  -- Ada.Strings.Wide_Unbounded.Wide_Text_IO
 184     ("a-tiocst", F),  -- Ada.Text_IO.C_Streams
 185     ("a-wtcstr", F),  -- Ada.Wide_Text_IO.C_Streams
 186
 187       --  Note: strictly the next two should be Ada 2005 units, but it seems
 188       --  harmless (and useful) to make then available in Ada 95 mode, since
 189       --  they only deal with Wide_Character, not Wide_Wide_Character.
 190
 191     ("a-wichun", F),  -- Ada.Wide_Characters.Unicode
 192     ("a-widcha", F),  -- Ada.Wide_Characters
 193
 194       --  Note: strictly the following should be Ada 2012 units, but it seems
 195       --  harmless (and useful) to make then available in Ada 95 mode, since
 196       --  they do not deal with Wide_Wide_Character.
 197
 198     ("a-wichha", F),  -- Ada.Wide_Characters.Handling
 199     ("a-stuten", F),  -- Ada.Strings.UTF_Encoding
 200     ("a-suenco", F),  -- Ada.Strings.UTF_Encoding.Conversions
 201     ("a-suenst", F),  -- Ada.Strings.UTF_Encoding.Strings
 202     ("a-suewst", F),  -- Ada.Strings.UTF_Encoding.Wide_Strings
 203
 204    ---------------------------
 205    -- GNAT Special IO Units --
 206    ---------------------------
 207
 208    --  As further explained elsewhere (see Sem_Ch10), the internal packages of
 209    --  Text_IO and Wide_Text_IO are actually implemented as separate children,
 210    --  but this fact is intended to be hidden from the user completely. Any
 211    --  attempt to WITH one of these units will be diagnosed as an error later
 212    --  on, but for now we do not consider these internal implementation units
 213    --  (if we did, then we would get a junk warning which would be confusing
 214    --  and unnecessary, given that we generate a clear error message).
 215
 216     ("a-tideio", F),  -- Ada.Text_IO.Decimal_IO
 217     ("a-tienio", F),  -- Ada.Text_IO.Enumeration_IO
 218     ("a-tifiio", F),  -- Ada.Text_IO.Fixed_IO
 219     ("a-tiflio", F),  -- Ada.Text_IO.Float_IO
 220     ("a-tiinio", F),  -- Ada.Text_IO.Integer_IO
 221     ("a-tiinio", F),  -- Ada.Text_IO.Integer_IO
 222     ("a-timoio", F),  -- Ada.Text_IO.Modular_IO
 223     ("a-wtdeio", F),  -- Ada.Wide_Text_IO.Decimal_IO
 224     ("a-wtenio", F),  -- Ada.Wide_Text_IO.Enumeration_IO
 225     ("a-wtfiio", F),  -- Ada.Wide_Text_IO.Fixed_IO
 226     ("a-wtflio", F),  -- Ada.Wide_Text_IO.Float_IO
 227     ("a-wtinio", F),  -- Ada.Wide_Text_IO.Integer_IO
 228     ("a-wtmoio", F),  -- Ada.Wide_Text_IO.Modular_IO
 229
 230    ------------------------
 231    -- GNAT Library Units --
 232    ------------------------
 233
 234     ("g-altive", F),  -- GNAT.Altivec
 235     ("g-altcon", F),  -- GNAT.Altivec.Conversions
 236     ("g-alveop", F),  -- GNAT.Altivec.Vector_Operations
 237     ("g-alvety", F),  -- GNAT.Altivec.Vector_Types
 238     ("g-alvevi", F),  -- GNAT.Altivec.Vector_Views
 239     ("g-arrspl", F),  -- GNAT.Array_Split
 240     ("g-awk   ", F),  -- GNAT.AWK
 241     ("g-boubuf", F),  -- GNAT.Bounded_Buffers
 242     ("g-boumai", F),  -- GNAT.Bounded_Mailboxes
 243     ("g-bubsor", F),  -- GNAT.Bubble_Sort
 244     ("g-busora", F),  -- GNAT.Bubble_Sort_A
 245     ("g-busorg", F),  -- GNAT.Bubble_Sort_G
 246     ("g-byorma", F),  -- GNAT.Byte_Order_Mark
 247     ("g-bytswa", F),  -- GNAT.Byte_Swapping
 248     ("g-calend", F),  -- GNAT.Calendar
 249     ("g-catiio", F),  -- GNAT.Calendar.Time_IO
 250     ("g-casuti", F),  -- GNAT.Case_Util
 251     ("g-cgi   ", F),  -- GNAT.CGI
 252     ("g-cgicoo", F),  -- GNAT.CGI.Cookie
 253     ("g-cgideb", F),  -- GNAT.CGI.Debug
 254     ("g-comlin", F),  -- GNAT.Command_Line
 255     ("g-comver", F),  -- GNAT.Compiler_Version
 256     ("g-crc32 ", F),  -- GNAT.CRC32
 257     ("g-ctrl_c", F),  -- GNAT.Ctrl_C
 258     ("g-curexc", F),  -- GNAT.Current_Exception
 259     ("g-debpoo", F),  -- GNAT.Debug_Pools
 260     ("g-debuti", F),  -- GNAT.Debug_Utilities
 261     ("g-decstr", F),  -- GNAT.Decode_String
 262     ("g-deutst", F),  -- GNAT.Decode_UTF8_String
 263     ("g-dirope", F),  -- GNAT.Directory_Operations
 264     ("g-diopit", F),  -- GNAT.Directory_Operations.Iteration
 265     ("g-dynhta", F),  -- GNAT.Dynamic_HTables
 266     ("g-dyntab", F),  -- GNAT.Dynamic_Tables
 267     ("g-encstr", F),  -- GNAT.Encode_String
 268     ("g-enutst", F),  -- GNAT.Encode_UTF8_String
 269     ("g-excact", F),  -- GNAT.Exception_Actions
 270     ("g-except", F),  -- GNAT.Exceptions
 271     ("g-exctra", F),  -- GNAT.Exception_Traces
 272     ("g-expect", F),  -- GNAT.Expect
 273     ("g-exptty", F),  -- GNAT.Expect.TTY
 274     ("g-flocon", F),  -- GNAT.Float_Control
 275     ("g-heasor", F),  -- GNAT.Heap_Sort
 276     ("g-hesora", F),  -- GNAT.Heap_Sort_A
 277     ("g-hesorg", F),  -- GNAT.Heap_Sort_G
 278     ("g-htable", F),  -- GNAT.Htable
 279     ("g-io    ", F),  -- GNAT.IO
 280     ("g-io_aux", F),  -- GNAT.IO_Aux
 281     ("g-locfil", F),  -- GNAT.Lock_Files
 282     ("g-mbdira", F),  -- GNAT.MBBS_Discrete_Random
 283     ("g-mbflra", F),  -- GNAT.MBBS_Float_Random
 284     ("g-md5   ", F),  -- GNAT.MD5
 285     ("g-memdum", F),  -- GNAT.Memory_Dump
 286     ("g-moreex", F),  -- GNAT.Most_Recent_Exception
 287     ("g-os_lib", F),  -- GNAT.Os_Lib
 288     ("g-pehage", F),  -- GNAT.Perfect_Hash_Generators
 289     ("g-rannum", F),  -- GNAT.Random_Numbers
 290     ("g-regexp", F),  -- GNAT.Regexp
 291     ("g-regist", F),  -- GNAT.Registry
 292     ("g-regpat", F),  -- GNAT.Regpat
 293     ("g-semaph", F),  -- GNAT.Semaphores
 294     ("g-sercom", F),  -- GNAT.Serial_Communications
 295     ("g-sestin", F),  -- GNAT.Secondary_Stack_Info
 296     ("g-sha1  ", F),  -- GNAT.SHA1
 297     ("g-sha224", F),  -- GNAT.SHA224
 298     ("g-sha256", F),  -- GNAT.SHA256
 299     ("g-sha384", F),  -- GNAT.SHA384
 300     ("g-sha512", F),  -- GNAT.SHA512
 301     ("g-signal", F),  -- GNAT.Signals
 302     ("g-socket", F),  -- GNAT.Sockets
 303     ("g-souinf", F),  -- GNAT.Source_Info
 304     ("g-speche", F),  -- GNAT.Spell_Checker
 305     ("g-spchge", F),  -- GNAT.Spell_Checker_Generic
 306     ("g-spitbo", F),  -- GNAT.Spitbol
 307     ("g-spipat", F),  -- GNAT.Spitbol.Patterns
 308     ("g-sptabo", F),  -- GNAT.Spitbol.Table_Boolean
 309     ("g-sptain", F),  -- GNAT.Spitbol.Table_Integer
 310     ("g-sptavs", F),  -- GNAT.Spitbol.Table_Vstring
 311     ("g-string", F),  -- GNAT.Strings
 312     ("g-strspl", F),  -- GNAT.String_Split
 313     ("g-sse   ", F),  -- GNAT.SSE
 314     ("g-ssvety", F),  -- GNAT.SSE.Vector_Types
 315     ("g-table ", F),  -- GNAT.Table
 316     ("g-tasloc", F),  -- GNAT.Task_Lock
 317     ("g-tastus", F),  -- GNAT.Task_Stack_Usage
 318     ("g-thread", F),  -- GNAT.Threads
 319     ("g-timsta", F),  -- GNAT.Time_Stamp
 320     ("g-traceb", F),  -- GNAT.Traceback
 321     ("g-trasym", F),  -- GNAT.Traceback.Symbolic
 322     ("g-tty   ", F),  -- GNAT.TTY
 323     ("g-utf_32", F),  -- GNAT.UTF_32
 324     ("g-u3spch", F),  -- GNAT.UTF_32_Spelling_Checker
 325     ("g-wispch", F),  -- GNAT.Wide_Spelling_Checker
 326     ("g-wistsp", F),  -- GNAT.Wide_String_Split
 327
 328    -----------------------------------------------------
 329    -- Interface Hierarchy Units from Reference Manual --
 330    -----------------------------------------------------
 331
 332     ("i-c     ", T),  -- Interfaces.C
 333     ("i-cobol ", T),  -- Interfaces.Cobol
 334     ("i-cpoint", T),  -- Interfaces.C.Pointers
 335     ("i-cstrin", T),  -- Interfaces.C.Strings
 336     ("i-fortra", T),  -- Interfaces.Fortran
 337
 338    ------------------------------------------
 339    -- GNAT Defined Additions to Interfaces --
 340    ------------------------------------------
 341
 342     ("i-cexten", F),  -- Interfaces.C.Extensions
 343     ("i-cil   ", F),  -- Interfaces.CIL
 344     ("i-cilobj", F),  -- Interfaces.CIL.Object
 345     ("i-cpp   ", F),  -- Interfaces.CPP
 346     ("i-cstrea", F),  -- Interfaces.C.Streams
 347     ("i-java  ", F),  -- Interfaces.Java
 348     ("i-javjni", F),  -- Interfaces.Java.JNI
 349     ("i-pacdec", F),  -- Interfaces.Packed_Decimal
 350     ("i-vxwoio", F),  -- Interfaces.VxWorks.IO
 351     ("i-vxwork", F),  -- Interfaces.VxWorks
 352
 353    --------------------------------------------------
 354    -- System Hierarchy Units from Reference Manual --
 355    --------------------------------------------------
 356
 357     ("s-atacco", T),  -- System.Address_To_Access_Conversions
 358     ("s-maccod", T),  -- System.Machine_Code
 359     ("s-rpc   ", T),  -- System.Rpc
 360     ("s-stoele", T),  -- System.Storage_Elements
 361     ("s-stopoo", T),  -- System.Storage_Pools
 362
 363    --------------------------------------
 364    -- GNAT Defined Additions to System --
 365    --------------------------------------
 366
 367     ("s-addima", F),  -- System.Address_Image
 368     ("s-assert", F),  -- System.Assertions
 369     ("s-diflio", F),  -- System.Dim.Float_IO
 370     ("s-diinio", F),  -- System.Dim.Integer_IO
 371     ("s-dimkio", F),  -- System.Dim.Mks_IO
 372     ("s-dimmks", F),  -- System.Dim.Mks
 373     ("s-dmotpr", F),  -- System.Dim.Mks.Other_Prefixes
 374     ("s-memory", F),  -- System.Memory
 375     ("s-parint", F),  -- System.Partition_Interface
 376     ("s-pooglo", F),  -- System.Pool_Global
 377     ("s-pooloc", F),  -- System.Pool_Local
 378     ("s-restri", F),  -- System.Restrictions
 379     ("s-rident", F),  -- System.Rident
 380     ("s-ststop", F),  -- System.Strings.Stream_Ops
 381     ("s-tasinf", F),  -- System.Task_Info
 382     ("s-wchcnv", F),  -- System.Wch_Cnv
 383     ("s-wchcon", F)); -- System.Wch_Con
 384
 385    --------------------
 386    -- Ada 2005 Units --
 387    --------------------
 388
 389    --  The following units should be used only in Ada 05 mode
 390
 391    Non_Imp_File_Names_05 : constant File_List := (
 392
 393    --------------------------------------------------------
 394    -- Ada Hierarchy Units from Ada 2005 Reference Manual --
 395    --------------------------------------------------------
 396
 397     ("a-assert", T),  -- Ada.Assertions
 398     ("a-calari", T),  -- Ada.Calendar.Arithmetic
 399     ("a-calfor", T),  -- Ada.Calendar.Formatting
 400     ("a-catizo", T),  -- Ada.Calendar.Time_Zones
 401     ("a-cdlili", T),  -- Ada.Containers.Doubly_Linked_Lists
 402     ("a-cgarso", T),  -- Ada.Containers.Generic_Array_Sort
 403     ("a-cgcaso", T),  -- Ada.Containers.Generic_Constrained_Array_Sort
 404     ("a-chacon", T),  -- Ada.Characters.Conversions
 405     ("a-cidlli", T),  -- Ada.Containers.Indefinite_Doubly_Linked_Lists
 406     ("a-cihama", T),  -- Ada.Containers.Indefinite_Hashed_Maps
 407     ("a-cihase", T),  -- Ada.Containers.Indefinite_Hashed_Sets
 408     ("a-ciorma", T),  -- Ada.Containers.Indefinite_Ordered_Maps
 409     ("a-ciorse", T),  -- Ada.Containers.Indefinite_Ordered_Sets
 410     ("a-cohama", T),  -- Ada.Containers.Hashed_Maps
 411     ("a-cohase", T),  -- Ada.Containers.Hashed_Sets
 412     ("a-coinve", T),  -- Ada.Containers.Indefinite_Vectors
 413     ("a-contai", T),  -- Ada.Containers
 414     ("a-convec", T),  -- Ada.Containers.Vectors
 415     ("a-coorma", T),  -- Ada.Containers.Ordered_Maps
 416     ("a-coorse", T),  -- Ada.Containers.Ordered_Sets
 417     ("a-coteio", T),  -- Ada.Complex_Text_IO
 418     ("a-direct", T),  -- Ada.Directories
 419     ("a-diroro", T),  -- Ada.Dispatching.Round_Robin
 420     ("a-disedf", T),  -- Ada.Dispatching.EDF
 421     ("a-dispat", T),  -- Ada.Dispatching
 422     ("a-envvar", T),  -- Ada.Environment_Variables
 423     ("a-etgrbu", T),  -- Ada.Execution_Time.Group_Budgets
 424     ("a-exetim", T),  -- Ada.Execution_Time
 425     ("a-extiti", T),  -- Ada.Execution_Time.Timers
 426     ("a-izteio", T),  -- Ada.Integer_Wide_Wide_Text_IO
 427     ("a-rttiev", T),  -- Ada.Real_Time.Timing_Events
 428     ("a-ngcoar", T),  -- Ada.Numerics.Generic_Complex_Arrays
 429     ("a-ngrear", T),  -- Ada.Numerics.Generic_Real_Arrays
 430     ("a-nucoar", T),  -- Ada.Numerics.Complex_Arrays
 431     ("a-nurear", T),  -- Ada.Numerics.Real_Arrays
 432     ("a-stboha", T),  -- Ada.Strings.Bounded.Hash
 433     ("a-stfiha", T),  -- Ada.Strings.Fixed.Hash
 434     ("a-strhas", T),  -- Ada.Strings.Hash
 435     ("a-stunha", T),  -- Ada.Strings.Unbounded.Hash
 436     ("a-stwiha", T),  -- Ada.Strings.Wide_Hash
 437     ("a-stzbou", T),  -- Ada.Strings.Wide_Wide_Bounded
 438     ("a-stzfix", T),  -- Ada.Strings.Wide_Wide_Fixed
 439     ("a-stzhas", T),  -- Ada.Strings.Wide_Wide_Hash
 440     ("a-stzmap", T),  -- Ada.Strings.Wide_Wide_Maps
 441     ("a-stzunb", T),  -- Ada.Strings.Wide_Wide_Unbounded
 442     ("a-swbwha", T),  -- Ada.Strings.Wide_Bounded.Wide_Hash
 443     ("a-swfwha", T),  -- Ada.Strings.Wide_Fixed.Wide_Hash
 444     ("a-swuwha", T),  -- Ada.Strings.Wide_Unbounded.Wide_Hash
 445     ("a-szbzha", T),  -- Ada.Strings.Wide_Wide_Bounded.Wide_Wide_Hash
 446     ("a-szfzha", T),  -- Ada.Strings.Wide_Wide_Fixed.Wide_Wide_Hash
 447     ("a-szmzco", T),  -- Ada.Strings.Wide_Wide_Maps.Wide_Wide_Constants
 448     ("a-szuzha", T),  -- Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Hash
 449     ("a-taster", T),  -- Ada.Task_Termination
 450     ("a-tgdico", T),  -- Ada.Tags.Generic_Dispatching_Constructor
 451     ("a-tiboio", T),  -- Ada.Text_IO.Bounded_IO
 452     ("a-tiunio", T),  -- Ada.Text_IO.Unbounded_IO
 453     ("a-wichun", T),  -- Ada.Wide_Characters.Unicode
 454     ("a-wwboio", T),  -- Ada.Wide_Text_IO.Wide_Bounded_IO
 455     ("a-wwunio", T),  -- Ada.Wide_Text_IO.Wide_Unbounded_IO
 456     ("a-zchara", T),  -- Ada.Wide_Wide_Characters
 457     ("a-zchhan", T),  -- Ada.Wide_Wide_Characters.Handling
 458     ("a-ztcoio", T),  -- Ada.Wide_Wide_Text_IO.Complex_IO
 459     ("a-ztedit", T),  -- Ada.Wide_Wide_Text_IO.Editing
 460     ("a-zttest", T),  -- Ada.Wide_Wide_Text_IO.Text_Streams
 461     ("a-ztexio", T),  -- Ada.Wide_Wide_Text_IO
 462     ("a-zzboio", T),  -- Ada.Wide_Wide_Text_IO.Wide_Wide_Bounded_IO
 463     ("a-zzunio", T),  -- Ada.Wide_Wide_Text_IO.Wide_Wide_Unbounded_IO
 464
 465    ------------------------------------------------------
 466    -- RM Required Additions to Ada 2005 for GNAT Types --
 467    ------------------------------------------------------
 468
 469    --  Note: Long versions are considered RM defined, but not the Long Long,
 470    --  Short, or Short_Short versions.
 471
 472     ("a-lcteio", T),  -- Ada.Long_Complex_Text_IO
 473     ("a-lfztio", T),  -- Ada.Long_Float_Wide_Wide_Text_IO
 474     ("a-liztio", T),  -- Ada.Long_Integer_Wide_Wide_Text_IO
 475     ("a-llctio", T),  -- Ada.Long_Long_Complex_Text_IO
 476     ("a-llfzti", T),  -- Ada.Long_Long_Float_Wide_Wide_Text_IO
 477     ("a-llizti", T),  -- Ada.Long_Long_Integer_Wide_Wide_Text_IO
 478     ("a-nlcoar", T),  -- Ada.Numerics.Long_Complex_Arrays
 479     ("a-nllcar", T),  -- Ada.Numerics.Long_Long_Complex_Arrays
 480     ("a-nllrar", T),  -- Ada.Numerics.Long_Long_Real_Arrays
 481     ("a-nlrear", T),  -- Ada.Numerics.Long_Real_Arrays
 482     ("a-scteio", F),  -- Ada.Short_Complex_Text_IO
 483     ("a-sfztio", F),  -- Ada.Short_Float_Wide_Wide_Text_IO
 484     ("a-siztio", F),  -- Ada.Short_Integer_Wide_Wide_Text_IO
 485     ("a-ssizti", F),  -- Ada.Short_Short_Integer_Wide_Wide_Text_IO
 486
 487    ----------------------------------------
 488    -- GNAT Defined Additions to Ada 2005 --
 489    ----------------------------------------
 490
 491     ("a-cgaaso", F),  -- Ada.Containers.Generic_Anonymous_Array_Sort
 492     ("a-chzla1", F),  -- Ada.Characters.Wide_Wide_Latin_1
 493     ("a-chzla9", F),  -- Ada.Characters.Wide_Wide_Latin_9
 494     ("a-ciormu", F),  -- Ada.Containers.Indefinite_Ordered_Multisets
 495     ("a-coormu", F),  -- Ada.Containers.Ordered_Multisets
 496     ("a-crdlli", F),  -- Ada.Containers.Restricted_Doubly_Linked_Lists
 497     ("a-szuzti", F),  -- Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO
 498     ("a-zchuni", F),  -- Ada.Wide_Wide_Characters.Unicode
 499     ("a-ztcstr", F),  -- Ada.Wide_Wide_Text_IO.C_Streams
 500
 501       --  Note: strictly the following should be Ada 2012 units, but it seems
 502       --  harmless (and useful) to make then available in Ada 2005 mode.
 503
 504     ("a-cogeso", T),  -- Ada.Containers.Generic_Sort
 505     ("a-secain", T),  -- Ada.Strings.Equal_Case_Insensitive
 506     ("a-shcain", T),  -- Ada.Strings.Hash_Case_Insensitive
 507     ("a-slcain", T),  -- Ada.Strings.Less_Case_Insensitive
 508     ("a-sfecin", T),  -- Ada.Strings.Fixed.Equal_Case_Insensitive
 509     ("a-sfhcin", T),  -- Ada.Strings.Fixed.Hash_Case_Insensitive
 510     ("a-sflcin", T),  -- Ada.Strings.Fixed.Less_Case_Insensitive
 511     ("a-sbecin", T),  -- Ada.Strings.Bounded.Equal_Case_Insensitive
 512     ("a-sbhcin", T),  -- Ada.Strings.Bounded.Hash_Case_Insensitive
 513     ("a-sblcin", T),  -- Ada.Strings.Bounded.Less_Case_Insensitive
 514     ("a-suecin", T),  -- Ada.Strings.Unbounded.Equal_Case_Insensitive
 515     ("a-suhcin", T),  -- Ada.Strings.Unbounded.Hash_Case_Insensitive
 516     ("a-sulcin", T),  -- Ada.Strings.Unbounded.Less_Case_Insensitive
 517     ("a-suezst", T),  -- Ada.Strings.UTF_Encoding.Wide_Wide_Strings
 518
 519    ---------------------------
 520    -- GNAT Special IO Units --
 521    ---------------------------
 522
 523    --  See Ada 95 section for further information. These packages are for the
 524    --  implementation of the Wide_Wide_Text_IO generic packages.
 525
 526     ("a-ztdeio", F),  -- Ada.Wide_Wide_Text_IO.Decimal_IO
 527     ("a-ztenio", F),  -- Ada.Wide_Wide_Text_IO.Enumeration_IO
 528     ("a-ztfiio", F),  -- Ada.Wide_Wide_Text_IO.Fixed_IO
 529     ("a-ztflio", F),  -- Ada.Wide_Wide_Text_IO.Float_IO
 530     ("a-ztinio", F),  -- Ada.Wide_Wide_Text_IO.Integer_IO
 531     ("a-ztmoio", F),  -- Ada.Wide_Wide_Text_IO.Modular_IO
 532
 533    ------------------------
 534    -- GNAT Library Units --
 535    ------------------------
 536
 537     ("g-zspche", F),  -- GNAT.Wide_Wide_Spelling_Checker
 538     ("g-zstspl", F)); -- GNAT.Wide_Wide_String_Split
 539
 540    --------------------
 541    -- Ada 2012 Units --
 542    --------------------
 543
 544    --  The following units should be used only in Ada 2012 mode
 545
 546    Non_Imp_File_Names_12 : constant File_List := (
 547     ("s-multip", T),  -- System.Multiprocessors
 548     ("s-mudido", T),  -- System.Multiprocessors.Dispatching_Domains
 549     ("s-stposu", T),  -- System.Storage_Pools.Subpools
 550     ("a-cobove", T),  -- Ada.Containers.Bounded_Vectors
 551     ("a-cbdlli", T),  -- Ada.Containers.Bounded_Doubly_Linked_Lists
 552     ("a-cborse", T),  -- Ada.Containers.Bounded_Ordered_Sets
 553     ("a-cborma", T),  -- Ada.Containers.Bounded_Ordered_Maps
 554     ("a-cbhase", T),  -- Ada.Containers.Bounded_Hashed_Sets
 555     ("a-cbhama", T),  -- Ada.Containers.Bounded_Hashed_Maps
 556     ("a-coinho", T),  -- Ada.Containers.Indefinite_Holders
 557     ("a-comutr", T),  -- Ada.Containers.Multiway_Trees
 558     ("a-cimutr", T),  -- Ada.Containers.Indefinite_Multiway_Trees
 559     ("a-cbmutr", T),  -- Ada.Containers.Bounded_Multiway_Trees
 560     ("a-csquin", T),  -- Ada.Containers.Synchronized_Queue_Interfaces
 561     ("a-cusyqu", T),  -- Ada.Containers.Unbounded_Synchronized_Queues
 562     ("a-cuprqu", T),  -- Ada.Containers.Unbounded_Priority_Queues
 563     ("a-cbsyqu", T),  -- Ada.Containers.Bounded_Synchronized_Queues
 564     ("a-cbprqu", T),  -- Ada.Containers.Bounded_Priority_Queues
 565     ("a-extiin", T),  -- Ada.Execution_Time.Interrupts
 566     ("a-iteint", T),  -- Ada.Iterator_Interfaces
 567     ("a-locale", T),  -- Ada.Locales
 568     ("a-synbar", T),  -- Ada.Synchronous_Barriers
 569     ("a-undesu", T),  -- Ada.Unchecked_Deallocate_Subpool
 570
 571    ----------------------------------------
 572    -- GNAT Defined Additions to Ada 2012 --
 573    ----------------------------------------
 574
 575     ("a-cofove", F),  -- Ada.Containers.Formal_Vectors
 576     ("a-cfdlli", F),  -- Ada.Containers.Formal_Doubly_Linked_Lists
 577     ("a-cforse", F),  -- Ada.Containers.Formal_Ordered_Sets
 578     ("a-cforma", F),  -- Ada.Containers.Formal_Ordered_Maps
 579     ("a-cfhase", F),  -- Ada.Containers.Formal_Hashed_Sets
 580     ("a-cfhama", F)); -- Ada.Containers.Formal_Hashed_Maps
 581
 582    -----------------------
 583    -- Alternative Units --
 584    -----------------------
 585
 586    --  For some implementation units, there is a unit in the GNAT library
 587    --  that has identical functionality that is usable. If we have such a
 588    --  case we record the appropriate Unit name in Error_Msg_String.
 589
 590    type Aunit_Record is record
 591       Fname : String (1 .. 6);
 592       Aname : String_Ptr;
 593    end record;
 594
 595    --  Array of alternative unit names
 596
 597    Scasuti : aliased String := "GNAT.Case_Util";
 598    Scrc32  : aliased String := "GNAT.CRC32";
 599    Shtable : aliased String := "GNAT.HTable";
 600    Sos_lib : aliased String := "GNAT.OS_Lib";
 601    Sregexp : aliased String := "GNAT.Regexp";
 602    Sregpat : aliased String := "GNAT.Regpat";
 603    Sstring : aliased String := "GNAT.Strings";
 604    Sstusta : aliased String := "GNAT.Task_Stack_Usage";
 605    Stasloc : aliased String := "GNAT.Task_Lock";
 606    Sutf_32 : aliased String := "GNAT.UTF_32";
 607
 608    --  Array giving mapping
 609
 610    Map_Array : constant array (1 .. 10) of Aunit_Record := (
 611                  ("casuti", Scasuti'Access),
 612                  ("crc32 ", Scrc32 'Access),
 613                  ("htable", Shtable'Access),
 614                  ("os_lib", Sos_lib'Access),
 615                  ("regexp", Sregexp'Access),
 616                  ("regpat", Sregpat'Access),
 617                  ("string", Sstring'Access),
 618                  ("stusta", Sstusta'Access),
 619                  ("tasloc", Stasloc'Access),
 620                  ("utf_32", Sutf_32'Access));
 621
 622    ----------------------
 623    -- Get_Kind_Of_Unit --
 624    ----------------------
 625
 626    function Get_Kind_Of_Unit (U : Unit_Number_Type) return Kind_Of_Unit is
 627       Fname : constant File_Name_Type := Unit_File_Name (U);
 628
 629    begin
 630       Error_Msg_Strlen := 0;
 631       Get_Name_String (Fname);
 632
 633       --  Ada/System/Interfaces are all Ada 95 units
 634
 635       if (Name_Len =  7 and then Name_Buffer (1 ..  7) = "ada.ads")
 636            or else
 637          (Name_Len = 10 and then Name_Buffer (1 .. 10) = "system.ads")
 638            or else
 639          (Name_Len = 12 and then Name_Buffer (1 .. 12) = "interfac.ads")
 640       then
 641          return Ada_95_Unit;
 642       end if;
 643
 644       --  If length of file name is greater than 12, not predefined. The value
 645       --  12 here is an 8 char name with extension .ads.
 646
 647       if Name_Len > 12 then
 648          return Not_Predefined_Unit;
 649       end if;
 650
 651       --  Not predefined if file name does not start with a- g- s- i-
 652
 653       if Name_Len < 3
 654         or else Name_Buffer (2) /= '-'
 655         or else (Name_Buffer (1) /= 'a'
 656                    and then
 657                  Name_Buffer (1) /= 'g'
 658                    and then
 659                  Name_Buffer (1) /= 'i'
 660                    and then
 661                  Name_Buffer (1) /= 's')
 662       then
 663          return Not_Predefined_Unit;
 664       end if;
 665
 666       --  To be considered predefined, the file name must end in .ads or .adb.
 667       --  File names with other extensions (coming from the use of non-standard
 668       --  file naming schemes) can never be predefined.
 669
 670       --  Note that in the context of a compiler, the .adb case will never
 671       --  arise. However it can arise for other tools, e.g. gnatprove uses
 672       --  this routine to detect when a construct comes from an instance of
 673       --  a generic defined in a predefined unit.
 674
 675       if Name_Buffer (Name_Len - 3 .. Name_Len) /= ".ads"
 676            and then
 677          Name_Buffer (Name_Len - 3 .. Name_Len) /= ".adb"
 678       then
 679          return Not_Predefined_Unit;
 680       end if;
 681
 682       --  Otherwise normalize file name to 8 characters
 683
 684       Name_Len := Name_Len - 4;
 685       while Name_Len < 8 loop
 686          Name_Len := Name_Len + 1;
 687          Name_Buffer (Name_Len) := ' ';
 688       end loop;
 689
 690       --  See if name is in 95 list
 691
 692       for J in Non_Imp_File_Names_95'Range loop
 693          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_95 (J).Fname then
 694             return Ada_95_Unit;
 695          end if;
 696       end loop;
 697
 698       --  See if name is in 2005 list
 699
 700       for J in Non_Imp_File_Names_05'Range loop
 701          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_05 (J).Fname then
 702             return Ada_2005_Unit;
 703          end if;
 704       end loop;
 705
 706       --  See if name is in 2012 list
 707
 708       for J in Non_Imp_File_Names_12'Range loop
 709          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_12 (J).Fname then
 710             return Ada_2012_Unit;
 711          end if;
 712       end loop;
 713
 714       --  Only remaining special possibilities are children of System.RPC and
 715       --  System.Garlic and special files of the form System.Aux...
 716
 717       Get_Name_String (Unit_Name (U));
 718
 719       if Name_Len > 12
 720         and then Name_Buffer (1 .. 11) = "system.rpc."
 721       then
 722          return Ada_95_Unit;
 723       end if;
 724
 725       if Name_Len > 15
 726         and then Name_Buffer (1 .. 14) = "system.garlic."
 727       then
 728          return Ada_95_Unit;
 729       end if;
 730
 731       if Name_Len > 11
 732         and then Name_Buffer (1 .. 10) = "system.aux"
 733       then
 734          return Ada_95_Unit;
 735       end if;
 736
 737       --  All tests failed, this is definitely an implementation unit. See if
 738       --  we have an alternative name.
 739
 740       Get_Name_String (Fname);
 741
 742       if Name_Len in 11 .. 12
 743         and then Name_Buffer (1 .. 2) = "s-"
 744         and then Name_Buffer (Name_Len - 3 .. Name_Len) = ".ads"
 745       then
 746          for J in Map_Array'Range loop
 747             if (Name_Len = 12 and then
 748                  Name_Buffer (3 .. 8) = Map_Array (J).Fname)
 749               or else
 750                (Name_Len = 11 and then
 751                  Name_Buffer (3 .. 7) = Map_Array (J).Fname (1 .. 5))
 752             then
 753                Error_Msg_Strlen := Map_Array (J).Aname'Length;
 754                Error_Msg_String (1 .. Error_Msg_Strlen) :=
 755                  Map_Array (J).Aname.all;
 756             end if;
 757          end loop;
 758       end if;
 759
 760       return Implementation_Unit;
 761    end Get_Kind_Of_Unit;
 762
 763    -------------------
 764    -- Is_Known_Unit --
 765    -------------------
 766
 767    function Is_Known_Unit (Nam : Node_Id) return Boolean is
 768       Unam : Unit_Name_Type;
 769       Fnam : File_Name_Type;
 770
 771    begin
 772       --  If selector is not an identifier (e.g. it is a character literal or
 773       --  some junk from a previous error), then definitely not a known unit.
 774
 775       if Nkind (Selector_Name (Nam)) /= N_Identifier then
 776          return False;
 777       end if;
 778
 779       --  Otherwise get corresponding file name
 780
 781       Unam := Get_Unit_Name (Nam);
 782       Fnam := Get_File_Name (Unam, Subunit => False);
 783       Get_Name_String (Fnam);
 784
 785       Error_Msg_Strlen := 0;
 786
 787       --  Ada/System/Interfaces are all Ada 95 units
 788
 789       if (Name_Len =  7 and then Name_Buffer (1 ..  7) = "ada.ads")
 790            or else
 791          (Name_Len = 10 and then Name_Buffer (1 .. 10) = "system.ads")
 792            or else
 793          (Name_Len = 12 and then Name_Buffer (1 .. 12) = "interfac.ads")
 794       then
 795          return True;
 796       end if;
 797
 798       --  Remove extension from file name
 799
 800       if Name_Buffer (Name_Len - 3 .. Name_Len) = ".adb"
 801            or else
 802          Name_Buffer (Name_Len - 3 .. Name_Len) = ".ads"
 803       then
 804          Name_Len := Name_Len - 4;
 805       else
 806          return False;
 807       end if;
 808
 809       --  Pad name to 8 characters
 810
 811       while Name_Len < 8 loop
 812          Name_Len := Name_Len + 1;
 813          Name_Buffer (Name_Len) := ' ';
 814       end loop;
 815
 816       --  If length more than 8, definitely not a match
 817
 818       if Name_Len /= 8 then
 819          return False;
 820       end if;
 821
 822       --  If length is 8, search our tables
 823
 824       for J in Non_Imp_File_Names_95'Range loop
 825          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_95 (J).Fname then
 826             return True;
 827          end if;
 828       end loop;
 829
 830       for J in Non_Imp_File_Names_05'Range loop
 831          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_05 (J).Fname then
 832             return True;
 833          end if;
 834       end loop;
 835
 836       for J in Non_Imp_File_Names_12'Range loop
 837          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_12 (J).Fname then
 838             return True;
 839          end if;
 840       end loop;
 841
 842       --  If not found, not known
 843
 844       return False;
 845
 846    --  A safety guard, if we get an exception during this processing then it
 847    --  is most likely the result of a previous error, or a peculiar case we
 848    --  have not thought of. Since this routine is only used for error message
 849    --  refinement, we will just return False.
 850
 851    exception
 852       when others =>
 853          return False;
 854    end Is_Known_Unit;
 855
 856    ---------------------------
 857    -- Not_Impl_Defined_Unit --
 858    ---------------------------
 859
 860    function Not_Impl_Defined_Unit (U : Unit_Number_Type) return Boolean is
 861       Fname : constant File_Name_Type := Unit_File_Name (U);
 862
 863    begin
 864       Error_Msg_Strlen := 0;
 865       Get_Name_String (Fname);
 866
 867       --  Ada/System/Interfaces are all RM-defined Ada 95 units
 868
 869       if (Name_Len =  7 and then Name_Buffer (1 ..  7) = "ada.ads")
 870            or else
 871          (Name_Len = 10 and then Name_Buffer (1 .. 10) = "system.ads")
 872            or else
 873          (Name_Len = 12 and then Name_Buffer (1 .. 12) = "interfac.ads")
 874       then
 875          return True;
 876       end if;
 877
 878       --  If length of file name is greater than 12, then it's a user unit
 879       --  and not a GNAT implementation defined unit.
 880
 881       if Name_Len > 12 then
 882          return True;
 883       end if;
 884
 885       --  Implementation defined if unit in the gnat hierarchy
 886
 887       if (Name_Len = 8 and then Name_Buffer (1 .. 8) = "gnat.ads")
 888         or else (Name_Len > 2 and then Name_Buffer (1 .. 2) = "g-")
 889       then
 890          return False;
 891       end if;
 892
 893       --  Not implementation defined if file name does not start with a- s- i-
 894
 895       if Name_Len < 3
 896         or else Name_Buffer (2) /= '-'
 897         or else (Name_Buffer (1) /= 'a'
 898                    and then
 899                  Name_Buffer (1) /= 'i'
 900                    and then
 901                  Name_Buffer (1) /= 's')
 902       then
 903          return True;
 904       end if;
 905
 906       --  Not impl-defined if file name does not end in .ads. This can happen
 907       --  when non-standard file names are being used.
 908
 909       if Name_Buffer (Name_Len - 3 .. Name_Len) /= ".ads" then
 910          return True;
 911       end if;
 912
 913       --  Otherwise normalize file name to 8 characters
 914
 915       Name_Len := Name_Len - 4;
 916       while Name_Len < 8 loop
 917          Name_Len := Name_Len + 1;
 918          Name_Buffer (Name_Len) := ' ';
 919       end loop;
 920
 921       --  Check our lists of names, if we find a match, return corresponding
 922       --  indication of whether the file is RM defined, respecting the RM
 923       --  version in which it is defined.
 924
 925       for J in Non_Imp_File_Names_95'Range loop
 926          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_95 (J).Fname then
 927             return Non_Imp_File_Names_95 (J).RMdef;
 928          end if;
 929       end loop;
 930
 931       for J in Non_Imp_File_Names_05'Range loop
 932          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_05 (J).Fname then
 933             return Non_Imp_File_Names_05 (J).RMdef
 934               and then Ada_Version >= Ada_2005;
 935          end if;
 936       end loop;
 937
 938       for J in Non_Imp_File_Names_12'Range loop
 939          if Name_Buffer (1 .. 8) = Non_Imp_File_Names_12 (J).Fname then
 940             return Non_Imp_File_Names_95 (J).RMdef
 941               and then Ada_Version >= Ada_2012;
 942          end if;
 943       end loop;
 944
 945       --  If unit is in System, Ada or Interfaces hierarchies and did not match
 946       --  any entry in the list, means it is an internal implementation defined
 947       --  unit which the restriction should definition forbid.
 948
 949       return True;
 950    end Not_Impl_Defined_Unit;
 951
 952 end Impunit;