1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                                N A M E T                                 --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2015, 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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32with Alloc;
33with Table;
34with Hostparm; use Hostparm;
35with System;   use System;
36with Types;    use Types;
37
38package Namet is
39
40--  WARNING: There is a C version of this package. Any changes to this
41--  source file must be properly reflected in the C header file namet.h
42--  which is created manually from namet.ads and namet.adb.
43
44--  This package contains routines for handling the names table. The table
45--  is used to store character strings for identifiers and operator symbols,
46--  as well as other string values such as unit names and file names.
47
48--  The forms of the entries are as follows:
49
50--    Identifiers        Stored with upper case letters folded to lower case.
51--                       Upper half (16#80# bit set) and wide characters are
52--                       stored in an encoded form (Uhh for upper half char,
53--                       Whhhh for wide characters, WWhhhhhhhh as provided by
54--                       the routine Store_Encoded_Character, where hh are hex
55--                       digits for the character code using lower case a-f).
56--                       Normally the use of U or W in other internal names is
57--                       avoided, but these letters may be used in internal
58--                       names (without this special meaning), if they appear
59--                       as the last character of the name, or they are
60--                       followed by an upper case letter (other than the WW
61--                       sequence), or an underscore.
62
63--    Operator symbols   Stored with an initial letter O, and the remainder
64--                       of the name is the lower case characters XXX where
65--                       the name is Name_Op_XXX, see Snames spec for a full
66--                       list of the operator names. Normally the use of O
67--                       in other internal names is avoided, but it may be
68--                       used in internal names (without this special meaning)
69--                       if it is the last character of the name, or if it is
70--                       followed by an upper case letter or an underscore.
71
72--    Character literals Character literals have names that are used only for
73--                       debugging and error message purposes. The form is an
74--                       upper case Q followed by a single lower case letter,
75--                       or by a Uxx/Wxxxx/WWxxxxxxx encoding as described for
76--                       identifiers. The Set_Character_Literal_Name procedure
77--                       should be used to construct these encodings. Normally
78--                       the use of O in other internal names is avoided, but
79--                       it may be used in internal names (without this special
80--                       meaning) if it is the last character of the name, or
81--                       if it is followed by an upper case letter or an
82--                       underscore.
83
84--    Unit names         Stored with upper case letters folded to lower case,
85--                       using Uhh/Whhhh/WWhhhhhhhh encoding as described for
86--                       identifiers, and a %s or %b suffix for specs/bodies.
87--                       See package Uname for further details.
88
89--    File names         Are stored in the form provided by Osint. Typically
90--                       they may include wide character escape sequences and
91--                       upper case characters (in non-encoded form). Casing
92--                       is also derived from the external environment. Note
93--                       that file names provided by Osint must generally be
94--                       consistent with the names from Fname.Get_File_Name.
95
96--    Other strings      The names table is also used as a convenient storage
97--                       location for other variable length strings such as
98--                       error messages etc. There are no restrictions on what
99--                       characters may appear for such entries.
100
101--  Note: the encodings Uhh (upper half characters), Whhhh (wide characters),
102--  WWhhhhhhhh (wide wide characters) and Qx (character literal names) are
103--  described in the spec, since they are visible throughout the system (e.g.
104--  in debugging output). However, no code should depend on these particular
105--  encodings, so it should be possible to change the encodings by making
106--  changes only to the Namet specification (to change these comments) and the
107--  body (which actually implements the encodings).
108
109--  The names are hashed so that a given name appears only once in the table,
110--  except that names entered with Name_Enter as opposed to Name_Find are
111--  omitted from the hash table.
112
113--  The first 26 entries in the names table (with Name_Id values in the range
114--  First_Name_Id .. First_Name_Id + 25) represent names which are the one
115--  character lower case letters in the range a-z, and these names are created
116--  and initialized by the Initialize procedure.
117
118--  Five values, one of type Int, one of type Byte, and three of type Boolean,
119--  are stored with each names table entry and subprograms are provided for
120--  setting and retrieving these associated values. The usage of these values
121--  is up to the client:
122
123--    In the compiler we have the following uses:
124
125--      The Int field is used to point to a chain of potentially visible
126--      entities (see Sem.Ch8 for details).
127
128--      The Byte field is used to hold the Token_Type value for reserved words
129--      (see Sem for details).
130
131--      The Boolean1 field is used to mark address clauses to optimize the
132--      performance of the Exp_Util.Following_Address_Clause function.
133
134--      The Boolean2 field is used to mark simple names that appear in
135--      Restriction[_Warning]s pragmas for No_Use_Of_Entity. This avoids most
136--      unnecessary searches of the No_Use_Of_Entity table.
137
138--      The Boolean3 field is set for names of pragmas that are to be ignored
139--      because of the occurrence of a corresponding pragma Ignore_Pragma.
140
141--    In the binder, we have the following uses:
142
143--      The Int field is used in various ways depending on the name involved,
144--      see binder documentation for details.
145
146--      The Byte and Boolean fields are unused.
147
148--  Note that the value of the Int and Byte fields are initialized to zero,
149--  and the Boolean field is initialized to False, when a new Name table entry
150--  is created.
151
152   Name_Buffer : String (1 .. 4 * Max_Line_Length);
153   --  This buffer is used to set the name to be stored in the table for the
154   --  Name_Find call, and to retrieve the name for the Get_Name_String call.
155   --  The limit here is intended to be an infinite value that ensures that we
156   --  never overflow the buffer (names this long are too absurd to worry).
157
158   Name_Len : Natural := 0;
159   --  Length of name stored in Name_Buffer. Used as an input parameter for
160   --  Name_Find, and as an output value by Get_Name_String, or Write_Name.
161   --  Note: in normal usage, all users of Name_Buffer/Name_Len are expected
162   --  to initialize Name_Len appropriately. The reason we preinitialize to
163   --  zero here is that some circuitry (e.g. Osint.Write_Program_Name) does
164   --  a save/restore on Name_Len and Name_Buffer (1 .. Name_Len), and we do
165   --  not want some arbitrary junk value to result in saving an arbitrarily
166   --  long slice which would waste time and blow the stack.
167
168   -----------------------------
169   -- Types for Namet Package --
170   -----------------------------
171
172   --  Name_Id values are used to identify entries in the names table. Except
173   --  for the special values No_Name and Error_Name, they are subscript values
174   --  for the Names table defined in this package.
175
176   --  Note that with only a few exceptions, which are clearly documented, the
177   --  type Name_Id should be regarded as a private type. In particular it is
178   --  never appropriate to perform arithmetic operations using this type.
179
180   type Name_Id is range Names_Low_Bound .. Names_High_Bound;
181   for Name_Id'Size use 32;
182   --  Type used to identify entries in the names table
183
184   No_Name : constant Name_Id := Names_Low_Bound;
185   --  The special Name_Id value No_Name is used in the parser to indicate
186   --  a situation where no name is present (e.g. on a loop or block).
187
188   Error_Name : constant Name_Id := Names_Low_Bound +  1;
189   --  The special Name_Id value Error_Name is used in the parser to
190   --  indicate that some kind of error was encountered in scanning out
191   --  the relevant name, so it does not have a representable label.
192
193   subtype Error_Name_Or_No_Name is Name_Id range No_Name .. Error_Name;
194   --  Used to test for either error name or no name
195
196   First_Name_Id : constant Name_Id := Names_Low_Bound + 2;
197   --  Subscript of first entry in names table
198
199   ------------------------------
200   -- Name_Id Membership Tests --
201   ------------------------------
202
203   --  The following functions allow a convenient notation for testing whether
204   --  a Name_Id value matches any one of a list of possible values. In each
205   --  case True is returned if the given T argument is equal to any of the V
206   --  arguments. These essentially duplicate the Ada 2012 membership tests,
207   --  but we cannot use the latter (yet) in the compiler front end, because
208   --  of bootstrap considerations
209
210   function Nam_In
211     (T  : Name_Id;
212      V1 : Name_Id;
213      V2 : Name_Id) return Boolean;
214
215   function Nam_In
216     (T  : Name_Id;
217      V1 : Name_Id;
218      V2 : Name_Id;
219      V3 : Name_Id) return Boolean;
220
221   function Nam_In
222     (T  : Name_Id;
223      V1 : Name_Id;
224      V2 : Name_Id;
225      V3 : Name_Id;
226      V4 : Name_Id) return Boolean;
227
228   function Nam_In
229     (T  : Name_Id;
230      V1 : Name_Id;
231      V2 : Name_Id;
232      V3 : Name_Id;
233      V4 : Name_Id;
234      V5 : Name_Id) return Boolean;
235
236   function Nam_In
237     (T  : Name_Id;
238      V1 : Name_Id;
239      V2 : Name_Id;
240      V3 : Name_Id;
241      V4 : Name_Id;
242      V5 : Name_Id;
243      V6 : Name_Id) return Boolean;
244
245   function Nam_In
246     (T  : Name_Id;
247      V1 : Name_Id;
248      V2 : Name_Id;
249      V3 : Name_Id;
250      V4 : Name_Id;
251      V5 : Name_Id;
252      V6 : Name_Id;
253      V7 : Name_Id) return Boolean;
254
255   function Nam_In
256     (T  : Name_Id;
257      V1 : Name_Id;
258      V2 : Name_Id;
259      V3 : Name_Id;
260      V4 : Name_Id;
261      V5 : Name_Id;
262      V6 : Name_Id;
263      V7 : Name_Id;
264      V8 : Name_Id) return Boolean;
265
266   function Nam_In
267     (T  : Name_Id;
268      V1 : Name_Id;
269      V2 : Name_Id;
270      V3 : Name_Id;
271      V4 : Name_Id;
272      V5 : Name_Id;
273      V6 : Name_Id;
274      V7 : Name_Id;
275      V8 : Name_Id;
276      V9 : Name_Id) return Boolean;
277
278   function Nam_In
279     (T   : Name_Id;
280      V1  : Name_Id;
281      V2  : Name_Id;
282      V3  : Name_Id;
283      V4  : Name_Id;
284      V5  : Name_Id;
285      V6  : Name_Id;
286      V7  : Name_Id;
287      V8  : Name_Id;
288      V9  : Name_Id;
289      V10 : Name_Id) return Boolean;
290
291   function Nam_In
292     (T   : Name_Id;
293      V1  : Name_Id;
294      V2  : Name_Id;
295      V3  : Name_Id;
296      V4  : Name_Id;
297      V5  : Name_Id;
298      V6  : Name_Id;
299      V7  : Name_Id;
300      V8  : Name_Id;
301      V9  : Name_Id;
302      V10 : Name_Id;
303      V11 : Name_Id) return Boolean;
304
305   pragma Inline (Nam_In);
306   --  Inline all above functions
307
308   -----------------
309   -- Subprograms --
310   -----------------
311
312   procedure Add_Char_To_Name_Buffer (C : Character);
313   pragma Inline (Add_Char_To_Name_Buffer);
314   --  Add given character to the end of the string currently stored in the
315   --  Name_Buffer, incrementing Name_Len.
316
317   procedure Add_Nat_To_Name_Buffer (V : Nat);
318   --  Add decimal representation of given value to the end of the string
319   --  currently stored in Name_Buffer, incrementing Name_Len as required.
320
321   procedure Add_Str_To_Name_Buffer (S : String);
322   --  Add characters of string S to the end of the string currently stored in
323   --  the Name_Buffer, incrementing Name_Len by the length of the string.
324
325   procedure Finalize;
326   --  Called at the end of a use of the Namet package (before a subsequent
327   --  call to Initialize). Currently this routine is only used to generate
328   --  debugging output.
329
330   procedure Get_Decoded_Name_String (Id : Name_Id);
331   --  Same calling sequence an interface as Get_Name_String, except that the
332   --  result is decoded, so that upper half characters and wide characters
333   --  appear as originally found in the source program text, operators have
334   --  their source forms (special characters and enclosed in quotes), and
335   --  character literals appear surrounded by apostrophes.
336
337   procedure Get_Decoded_Name_String_With_Brackets (Id : Name_Id);
338   --  This routine is similar to Decoded_Name, except that the brackets
339   --  notation (Uhh replaced by ["hh"], Whhhh replaced by ["hhhh"],
340   --  WWhhhhhhhh replaced by ["hhhhhhhh"]) is used for all non-lower half
341   --  characters, regardless of how Opt.Wide_Character_Encoding_Method is
342   --  set, and also in that characters in the range 16#80# .. 16#FF# are
343   --  converted to brackets notation in all cases. This routine can be used
344   --  when there is a requirement for a canonical representation not affected
345   --  by the character set options (e.g. in the binder generation of
346   --  symbols).
347
348   procedure Get_Last_Two_Chars
349     (N  : Name_Id;
350      C1 : out Character;
351      C2 : out Character);
352   --  Obtains last two characters of a name. C1 is last but one character and
353   --  C2 is last character. If name is less than two characters long then both
354   --  C1 and C2 are set to ASCII.NUL on return.
355
356   procedure Get_Name_String (Id : Name_Id);
357   --  Get_Name_String is used to retrieve the string associated with an entry
358   --  in the names table. The resulting string is stored in Name_Buffer and
359   --  Name_Len is set. It is an error to call Get_Name_String with one of the
360   --  special name Id values (No_Name or Error_Name).
361
362   function Get_Name_String (Id : Name_Id) return String;
363   --  This functional form returns the result as a string without affecting
364   --  the contents of either Name_Buffer or Name_Len. The lower bound is 1.
365
366   procedure Get_Name_String_And_Append (Id : Name_Id);
367   --  Like Get_Name_String but the resulting characters are appended to the
368   --  current contents of the entry stored in Name_Buffer, and Name_Len is
369   --  incremented to include the added characters.
370
371   function Get_Name_Table_Boolean1 (Id : Name_Id) return Boolean;
372   function Get_Name_Table_Boolean2 (Id : Name_Id) return Boolean;
373   function Get_Name_Table_Boolean3 (Id : Name_Id) return Boolean;
374   --  Fetches the Boolean values associated with the given name
375
376   function Get_Name_Table_Byte (Id : Name_Id) return Byte;
377   pragma Inline (Get_Name_Table_Byte);
378   --  Fetches the Byte value associated with the given name
379
380   function Get_Name_Table_Int (Id : Name_Id) return Int;
381   pragma Inline (Get_Name_Table_Int);
382   --  Fetches the Int value associated with the given name
383
384   procedure Get_Unqualified_Decoded_Name_String (Id : Name_Id);
385   --  Similar to the above except that qualification (as defined in unit
386   --  Exp_Dbug) is removed (including both preceding __ delimited names, and
387   --  also the suffix used to indicate package body entities). Note that
388   --  names are not qualified until just before the call to gigi, so this
389   --  routine is only needed by processing that occurs after gigi has been
390   --  called. This includes all ASIS processing, since ASIS works on the tree
391   --  written after gigi has been called.
392
393   procedure Get_Unqualified_Name_String (Id : Name_Id);
394   --  Similar to the above except that qualification (as defined in unit
395   --  Exp_Dbug) is removed (including both preceding __ delimited names, and
396   --  also the suffixes used to indicate package body entities and to
397   --  distinguish between overloaded entities). Note that names are not
398   --  qualified until just before the call to gigi, so this routine is only
399   --  needed by processing that occurs after gigi has been called. This
400   --  includes all ASIS processing, since ASIS works on the tree written
401   --  after gigi has been called.
402
403   procedure Initialize;
404   --  This is a dummy procedure. It is retained for easy compatibility with
405   --  clients who used to call Initialize when this call was required. Now
406   --  initialization is performed automatically during package elaboration.
407   --  Note that this change fixes problems which existed prior to the change
408   --  of Initialize being called more than once. See also Reinitialize which
409   --  allows reinitialization of the tables.
410
411   procedure Insert_Str_In_Name_Buffer (S : String; Index : Positive);
412   --  Inserts given string in name buffer, starting at Index. Any existing
413   --  characters at or past this location get moved beyond the inserted string
414   --  and Name_Len is incremented by the length of the string.
415
416   function Is_Internal_Name return Boolean;
417   --  Like the form with an Id argument, except that the name to be tested is
418   --  passed in Name_Buffer and Name_Len (which are not affected by the call).
419   --  Name_Buffer (it loads these as for Get_Name_String).
420
421   function Is_Internal_Name (Id : Name_Id) return Boolean;
422   --  Returns True if the name is an internal name (i.e. contains a character
423   --  for which Is_OK_Internal_Letter is true, or if the name starts or ends
424   --  with an underscore. This call destroys the value of Name_Len and
425   --  Name_Buffer (it loads these as for Get_Name_String).
426   --
427   --  Note: if the name is qualified (has a double underscore), then only the
428   --  final entity name is considered, not the qualifying names. Consider for
429   --  example that the name:
430   --
431   --    pkg__B_1__xyz
432   --
433   --  is not an internal name, because the B comes from the internal name of
434   --  a qualifying block, but the xyz means that this was indeed a declared
435   --  identifier called "xyz" within this block and there is nothing internal
436   --  about that name.
437
438   function Is_OK_Internal_Letter (C : Character) return Boolean;
439   pragma Inline (Is_OK_Internal_Letter);
440   --  Returns true if C is a suitable character for using as a prefix or a
441   --  suffix of an internally generated name, i.e. it is an upper case letter
442   --  other than one of the ones used for encoding source names (currently the
443   --  set of reserved letters is O, Q, U, W) and also returns False for the
444   --  letter X, which is reserved for debug output (see Exp_Dbug).
445
446   function Is_Operator_Name (Id : Name_Id) return Boolean;
447   --  Returns True if name given is of the form of an operator (that is, it
448   --  starts with an upper case O).
449
450   function Is_Valid_Name (Id : Name_Id) return Boolean;
451   --  True if Id is a valid name - points to a valid entry in the Name_Entries
452   --  table.
453
454   function Length_Of_Name (Id : Name_Id) return Nat;
455   pragma Inline (Length_Of_Name);
456   --  Returns length of given name in characters. This is the length of the
457   --  encoded name, as stored in the names table, the result is equivalent to
458   --  calling Get_Name_String and reading Name_Len, except that a call to
459   --  Length_Of_Name does not affect the contents of Name_Len and Name_Buffer.
460
461   procedure Lock;
462   --  Lock name tables before calling back end. We reserve some extra space
463   --  before locking to avoid unnecessary inefficiencies when we unlock.
464
465   function Name_Chars_Address return System.Address;
466   --  Return starting address of name characters table (used in Back_End call
467   --  to Gigi).
468
469   function Name_Enter return Name_Id;
470   --  Name_Enter has the same calling interface as Name_Find. The difference
471   --  is that it does not search the table for an existing match, and also
472   --  subsequent Name_Find calls using the same name will not locate the
473   --  entry created by this call. Thus multiple calls to Name_Enter with the
474   --  same name will create multiple entries in the name table with different
475   --  Name_Id values. This is useful in the case of created names, which are
476   --  never expected to be looked up. Note: Name_Enter should never be used
477   --  for one character names, since these are efficiently located without
478   --  hashing by Name_Find in any case.
479
480   function Name_Entries_Address return System.Address;
481   --  Return starting address of Names table (used in Back_End call to Gigi)
482
483   function Name_Entries_Count return Nat;
484   --  Return current number of entries in the names table
485
486   function Name_Equals (N1 : Name_Id; N2 : Name_Id) return Boolean;
487   --  Return whether N1 and N2 denote the same character sequence
488
489   function Name_Find return Name_Id;
490   --  Name_Find is called with a string stored in Name_Buffer whose length is
491   --  in Name_Len (i.e. the characters of the name are in subscript positions
492   --  1 to Name_Len in Name_Buffer). It searches the names table to see if the
493   --  string has already been stored. If so the Id of the existing entry is
494   --  returned. Otherwise a new entry is created with its Name_Table_Int
495   --  fields set to zero/false. The contents of Name_Buffer and Name_Len are
496   --  not modified by this call. Note that it is permissible for Name_Len to
497   --  be set to zero to lookup the null name string.
498
499   function Name_Find_Str (S : String) return Name_Id;
500   --  Similar to Name_Find, except that the string is provided as an argument.
501   --  This call destroys the contents of Name_Buffer and Name_Len (by storing
502   --  the given string there.
503
504   procedure Reinitialize;
505   --  Clears the name tables and removes all existing entries from the table.
506
507   procedure Reset_Name_Table;
508   --  This procedure is used when there are multiple source files to reset the
509   --  name table info entries associated with current entries in the names
510   --  table. There is no harm in keeping the names entries themselves from one
511   --  compilation to another, but we can't keep the entity info, since this
512   --  refers to tree nodes, which are destroyed between each main source file.
513
514   procedure Set_Character_Literal_Name (C : Char_Code);
515   --  This procedure sets the proper encoded name for the character literal
516   --  for the given character code. On return Name_Buffer and Name_Len are
517   --  set to reflect the stored name.
518
519   procedure Set_Name_Table_Byte (Id : Name_Id; Val : Byte);
520   pragma Inline (Set_Name_Table_Byte);
521   --  Sets the Byte value associated with the given name
522
523   procedure Set_Name_Table_Int (Id : Name_Id; Val : Int);
524   pragma Inline (Set_Name_Table_Int);
525   --  Sets the Int value associated with the given name
526
527   procedure Set_Name_Table_Boolean1 (Id : Name_Id; Val : Boolean);
528   procedure Set_Name_Table_Boolean2 (Id : Name_Id; Val : Boolean);
529   procedure Set_Name_Table_Boolean3 (Id : Name_Id; Val : Boolean);
530   --  Sets the Boolean value associated with the given name
531
532   procedure Store_Encoded_Character (C : Char_Code);
533   --  Stores given character code at the end of Name_Buffer, updating the
534   --  value in Name_Len appropriately. Lower case letters and digits are
535   --  stored unchanged. Other 8-bit characters are stored using the Uhh
536   --  encoding (hh = hex code), other 16-bit wide character values are stored
537   --  using the Whhhh (hhhh = hex code) encoding, and other 32-bit wide wide
538   --  character values are stored using the WWhhhhhhhh (hhhhhhhh = hex code).
539   --  Note that this procedure does not fold upper case letters (they are
540   --  stored using the Uhh encoding). If folding is required, it must be done
541   --  by the caller prior to the call.
542
543   procedure Tree_Read;
544   --  Initializes internal tables from current tree file using the relevant
545   --  Table.Tree_Read routines. Note that Initialize should not be called if
546   --  Tree_Read is used. Tree_Read includes all necessary initialization.
547
548   procedure Tree_Write;
549   --  Writes out internal tables to current tree file using the relevant
550   --  Table.Tree_Write routines.
551
552   procedure Unlock;
553   --  Unlocks the name table to allow use of the extra space reserved by the
554   --  call to Lock. See gnat1drv for details of the need for this.
555
556   procedure Write_Name (Id : Name_Id);
557   --  Write_Name writes the characters of the specified name using the
558   --  standard output procedures in package Output. No end of line is
559   --  written, just the characters of the name. On return Name_Buffer and
560   --  Name_Len are set as for a call to Get_Name_String. The name is written
561   --  in encoded form (i.e. including Uhh, Whhh, Qx, _op as they appear in
562   --  the name table). If Id is Error_Name, or No_Name, no text is output.
563
564   procedure Write_Name_Decoded (Id : Name_Id);
565   --  Like Write_Name, except that the name written is the decoded name, as
566   --  described for Get_Decoded_Name_String, and the resulting value stored
567   --  in Name_Len and Name_Buffer is the decoded name.
568
569   ------------------------------
570   -- File and Unit Name Types --
571   ------------------------------
572
573   --  These are defined here in Namet rather than Fname and Uname to avoid
574   --  problems with dependencies, and to avoid dragging in Fname and Uname
575   --  into many more files, but it would be cleaner to move to Fname/Uname.
576
577   type File_Name_Type is new Name_Id;
578   --  File names are stored in the names table and this type is used to
579   --  indicate that a Name_Id value is being used to hold a simple file name
580   --  (which does not include any directory information).
581
582   No_File : constant File_Name_Type := File_Name_Type (No_Name);
583   --  Constant used to indicate no file is present (this is used for example
584   --  when a search for a file indicates that no file of the name exists).
585
586   Error_File_Name : constant File_Name_Type := File_Name_Type (Error_Name);
587   --  The special File_Name_Type value Error_File_Name is used to indicate
588   --  a unit name where some previous processing has found an error.
589
590   subtype Error_File_Name_Or_No_File is
591     File_Name_Type range No_File .. Error_File_Name;
592   --  Used to test for either error file name or no file
593
594   type Path_Name_Type is new Name_Id;
595   --  Path names are stored in the names table and this type is used to
596   --  indicate that a Name_Id value is being used to hold a path name (that
597   --  may contain directory information).
598
599   No_Path : constant Path_Name_Type := Path_Name_Type (No_Name);
600   --  Constant used to indicate no path name is present
601
602   type Unit_Name_Type is new Name_Id;
603   --  Unit names are stored in the names table and this type is used to
604   --  indicate that a Name_Id value is being used to hold a unit name, which
605   --  terminates in %b for a body or %s for a spec.
606
607   No_Unit_Name : constant Unit_Name_Type := Unit_Name_Type (No_Name);
608   --  Constant used to indicate no file name present
609
610   Error_Unit_Name : constant Unit_Name_Type := Unit_Name_Type (Error_Name);
611   --  The special Unit_Name_Type value Error_Unit_Name is used to indicate
612   --  a unit name where some previous processing has found an error.
613
614   subtype Error_Unit_Name_Or_No_Unit_Name is
615     Unit_Name_Type range No_Unit_Name .. Error_Unit_Name;
616
617   ------------------------
618   -- Debugging Routines --
619   ------------------------
620
621   procedure wn (Id : Name_Id);
622   pragma Export (Ada, wn);
623   --  This routine is intended for debugging use only (i.e. it is intended to
624   --  be called from the debugger). It writes the characters of the specified
625   --  name using the standard output procedures in package Output, followed by
626   --  a new line. The name is written in encoded form (i.e. including Uhh,
627   --  Whhh, Qx, _op as they appear in the name table). If Id is Error_Name,
628   --  No_Name, or invalid an appropriate string is written (<Error_Name>,
629   --  <No_Name>, <invalid name>). Unlike Write_Name, this call does not affect
630   --  the contents of Name_Buffer or Name_Len.
631
632   ---------------------------
633   -- Table Data Structures --
634   ---------------------------
635
636   --  The following declarations define the data structures used to store
637   --  names. The definitions are in the private part of the package spec,
638   --  rather than the body, since they are referenced directly by gigi.
639
640private
641
642   --  This table stores the actual string names. Although logically there is
643   --  no need for a terminating character (since the length is stored in the
644   --  name entry table), we still store a NUL character at the end of every
645   --  name (for convenience in interfacing to the C world).
646
647   package Name_Chars is new Table.Table (
648     Table_Component_Type => Character,
649     Table_Index_Type     => Int,
650     Table_Low_Bound      => 0,
651     Table_Initial        => Alloc.Name_Chars_Initial,
652     Table_Increment      => Alloc.Name_Chars_Increment,
653     Table_Name           => "Name_Chars");
654
655   type Name_Entry is record
656      Name_Chars_Index : Int;
657      --  Starting location of characters in the Name_Chars table minus one
658      --  (i.e. pointer to character just before first character). The reason
659      --  for the bias of one is that indexes in Name_Buffer are one's origin,
660      --  so this avoids unnecessary adds and subtracts of 1.
661
662      Name_Len : Short;
663      --  Length of this name in characters
664
665      Byte_Info : Byte;
666      --  Byte value associated with this name
667
668      Boolean1_Info : Boolean;
669      Boolean2_Info : Boolean;
670      Boolean3_Info : Boolean;
671      --  Boolean values associated with the name
672
673      Name_Has_No_Encodings : Boolean;
674      --  This flag is set True if the name entry is known not to contain any
675      --  special character encodings. This is used to speed up repeated calls
676      --  to Get_Decoded_Name_String. A value of False means that it is not
677      --  known whether the name contains any such encodings.
678
679      Hash_Link : Name_Id;
680      --  Link to next entry in names table for same hash code
681
682      Int_Info : Int;
683      --  Int Value associated with this name
684
685   end record;
686
687   for Name_Entry use record
688      Name_Chars_Index      at  0 range 0 .. 31;
689      Name_Len              at  4 range 0 .. 15;
690      Byte_Info             at  6 range 0 .. 7;
691      Boolean1_Info         at  7 range 0 .. 0;
692      Boolean2_Info         at  7 range 1 .. 1;
693      Boolean3_Info         at  7 range 2 .. 2;
694      Name_Has_No_Encodings at  7 range 3 .. 7;
695      Hash_Link             at  8 range 0 .. 31;
696      Int_Info              at 12 range 0 .. 31;
697   end record;
698
699   for Name_Entry'Size use 16 * 8;
700   --  This ensures that we did not leave out any fields
701
702   --  This is the table that is referenced by Name_Id entries.
703   --  It contains one entry for each unique name in the table.
704
705   package Name_Entries is new Table.Table (
706     Table_Component_Type => Name_Entry,
707     Table_Index_Type     => Name_Id'Base,
708     Table_Low_Bound      => First_Name_Id,
709     Table_Initial        => Alloc.Names_Initial,
710     Table_Increment      => Alloc.Names_Increment,
711     Table_Name           => "Name_Entries");
712
713end Namet;
714