1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
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. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 -- This package contains the input routines used for reading the
27 -- input source file. The actual I/O routines are in OS_Interface,
28 -- with this module containing only the system independent processing.
30 -- General Note: throughout the compiler, we use the term line or source
31 -- line to refer to a physical line in the source, terminated by the end of
32 -- physical line sequence.
34 -- There are two distinct concepts of line terminator in GNAT
36 -- A logical line terminator is what corresponds to the "end of a line" as
37 -- described in RM 2.2 (13). Any of the characters FF, LF, CR or VT or any
38 -- wide character that is a Line or Paragraph Separator acts as an end of
39 -- logical line in this sense, and it is essentially irrelevant whether one
40 -- or more appears in sequence (since if a sequence of such characters is
41 -- regarded as separate ends of line, then the intervening logical lines
42 -- are null in any case).
44 -- A physical line terminator is a sequence of format effectors that is
45 -- treated as ending a physical line. Physical lines have no Ada semantic
46 -- significance, but they are significant for error reporting purposes,
47 -- since errors are identified by line and column location.
49 -- In GNAT, a physical line is ended by any of the sequences LF, CR/LF, or
50 -- CR. LF is used in typical Unix systems, CR/LF in DOS systems, and CR
51 -- alone in System 7. In addition, we recognize any of these sequences in
52 -- any of the operating systems, for better behavior in treating foreign
53 -- files (e.g. a Unix file with LF terminators transferred to a DOS system).
54 -- Finally, wide character codes in categories Separator, Line and Separator,
55 -- Paragraph are considered to be physical line terminators.
58 with Casing; use Casing;
59 with Namet; use Namet;
62 with Types; use Types;
66 type Type_Of_File is (
67 -- Indicates type of file being read
70 -- Normal Ada source file
73 -- Configuration pragma file
76 -- Preprocessing definition file
79 -- Source file with preprocessing commands to be preprocessed
81 type Instance_Id is new Nat;
82 No_Instance_Id : constant Instance_Id;
84 ----------------------------
85 -- Source License Control --
86 ----------------------------
88 -- The following type indicates the license state of a source if it
93 -- Licensing status of this source unit is unknown
96 -- This is a non-GPL'ed unit that is restricted from depending
97 -- on GPL'ed units (e.g. proprietary code is in this category)
100 -- This file is licensed under the unmodified GPL. It is not allowed
101 -- to depend on Non_GPL units, and Non_GPL units may not depend on
105 -- This file is licensed under the GNAT modified GPL (see header of
106 -- This file for wording of the modification). It may depend on other
107 -- Modified_GPL units or on unrestricted units.
110 -- The license on this file is permitted to depend on any other
111 -- units, or have other units depend on it, without violating the
112 -- license of this unit. Examples are public domain units, and
113 -- units defined in the RM).
115 -- The above license status is checked when the appropriate check is
116 -- activated and one source depends on another, and the licensing state
117 -- of both files is known:
119 -- The prohibited combinations are:
121 -- Restricted file may not depend on GPL file
123 -- GPL file may not depend on Restricted file
125 -- Modified GPL file may not depend on Restricted file
126 -- Modified_GPL file may not depend on GPL file
128 -- The reason for the last restriction here is that a client depending
129 -- on a modified GPL file must be sure that the license condition is
130 -- correct considered transitively.
132 -- The licensing status is determined either by the presence of a
133 -- specific pragma License, or by scanning the header for a predefined
134 -- statement, or any file if compiling in -gnatg mode.
136 -----------------------
137 -- Source File Table --
138 -----------------------
140 -- The source file table has an entry for each source file read in for
141 -- this run of the compiler. This table is (default) initialized when
142 -- the compiler is loaded, and simply accumulates entries as compilation
143 -- proceeds and various routines in Sinput and its child packages are
144 -- called to load required source files.
146 -- Virtual entries are also created for generic templates when they are
147 -- instantiated, as described in a separate section later on.
149 -- In the case where there are multiple main units (e.g. in the case of
150 -- the cross-reference tool), this table is not reset between these units,
151 -- so that a given source file is only read once if it is used by two
152 -- separate main units.
154 -- The entries in the table are accessed using a Source_File_Index that
155 -- ranges from 1 to Last_Source_File. Each entry has the following fields.
157 -- Note: fields marked read-only are set by Sinput or one of its child
158 -- packages when a source file table entry is created, and cannot be
159 -- subsequently modified, or alternatively are set only by very special
160 -- circumstances, documented in the comments.
162 -- File_Name : File_Name_Type (read-only)
163 -- Name of the source file (simple name with no directory information)
165 -- Full_File_Name : File_Name_Type (read-only)
166 -- Full file name (full name with directory info), used for generation
167 -- of error messages, etc.
169 -- File_Type : Type_Of_File (read-only)
170 -- Indicates type of file (source file, configuration pragmas file,
171 -- preprocessor definition file, preprocessor input file).
173 -- Reference_Name : File_Name_Type (read-only)
174 -- Name to be used for source file references in error messages where
175 -- only the simple name of the file is required. Identical to File_Name
176 -- unless pragma Source_Reference is used to change it. Only processing
177 -- for the Source_Reference pragma circuit may set this field.
179 -- Full_Ref_Name : File_Name_Type (read-only)
180 -- Name to be used for source file references in error messages where
181 -- the full name of the file is required. Identical to Full_File_Name
182 -- unless pragma Source_Reference is used to change it. Only processing
183 -- for the Source_Reference pragma may set this field.
185 -- Debug_Source_Name : File_Name_Type (read-only)
186 -- Name to be used for source file references in debugging information
187 -- where only the simple name of the file is required. Identical to
188 -- Reference_Name unless the -gnatD (debug source file) switch is used.
189 -- Only processing in Sprint that generates this file is permitted to
192 -- Full_Debug_Name : File_Name_Type (read-only)
193 -- Name to be used for source file references in debugging information
194 -- where the full name of the file is required. This is identical to
195 -- Full_Ref_Name unless the -gnatD (debug source file) switch is used.
196 -- Only processing in Sprint that generates this file is permitted to
199 -- Instance : Instance_Id (read-only)
200 -- For entries corresponding to a generic instantiation, unique
201 -- identifier denoting the full chain of nested instantiations. Set to
202 -- No_Instance_Id for the case of a normal, non-instantiation entry.
203 -- See below for details on the handling of generic instantiations.
205 -- License : License_Type;
206 -- License status of source file
208 -- Num_SRef_Pragmas : Nat;
209 -- Number of source reference pragmas present in source file
211 -- First_Mapped_Line : Logical_Line_Number;
212 -- This field stores logical line number of the first line in the
213 -- file that is not a Source_Reference pragma. If no source reference
214 -- pragmas are used, then the value is set to No_Line_Number.
216 -- Source_Text : Source_Buffer_Ptr (read-only)
217 -- Text of source file. Every source file has a distinct set of
218 -- nonoverlapping bounds, so it is possible to determine which
219 -- file is referenced from a given subscript (Source_Ptr) value.
221 -- Source_First : Source_Ptr; (read-only)
222 -- This is always equal to Source_Text'First, except during
223 -- construction of a debug output file (*.dg), when Source_Text = null,
224 -- and Source_First is the size so far. Likewise for Last.
226 -- Source_Last : Source_Ptr; (read-only)
227 -- Same idea as Source_Last, but for Last
229 -- Time_Stamp : Time_Stamp_Type; (read-only)
230 -- Time stamp of the source file
232 -- Source_Checksum : Word;
233 -- Computed checksum for contents of source file. See separate section
234 -- later on in this spec for a description of the checksum algorithm.
236 -- Last_Source_Line : Physical_Line_Number;
237 -- Physical line number of last source line. While a file is being
238 -- read, this refers to the last line scanned. Once a file has been
239 -- completely scanned, it is the number of the last line in the file,
240 -- and hence also gives the number of source lines in the file.
242 -- Keyword_Casing : Casing_Type;
243 -- Casing style used in file for keyword casing. This is initialized
244 -- to Unknown, and then set from the first occurrence of a keyword.
245 -- This value is used only for formatting of error messages.
247 -- Identifier_Casing : Casing_Type;
248 -- Casing style used in file for identifier casing. This is initialized
249 -- to Unknown, and then set from an identifier in the program as soon as
250 -- one is found whose casing is sufficiently clear to make a decision.
251 -- This value is used for formatting of error messages, and also is used
252 -- in the detection of keywords misused as identifiers.
254 -- Inlined_Call : Source_Ptr;
255 -- Source file location of the subprogram call if this source file entry
256 -- represents an inlined body or an inherited pragma. Set to No_Location
257 -- otherwise. This field is read-only for clients.
259 -- Inlined_Body : Boolean;
260 -- This can only be set True if Instantiation has a value other than
261 -- No_Location. If true it indicates that the instantiation is actually
262 -- an instance of an inlined body.
264 -- Inherited_Pragma : Boolean;
265 -- This can only be set True if Instantiation has a value other than
266 -- No_Location. If true it indicates that the instantiation is actually
267 -- an inherited class-wide pre- or postcondition.
269 -- Template : Source_File_Index; (read-only)
270 -- Source file index of the source file containing the template if this
271 -- is a generic instantiation. Set to No_Source_File for the normal case
272 -- of a non-instantiation entry. See Sinput-L for details.
274 -- Unit : Unit_Number_Type;
275 -- Identifies the unit contained in this source file. Set by
276 -- Initialize_Scanner, must not be subsequently altered.
278 -- The source file table is accessed by clients using the following
279 -- subprogram interface:
281 subtype SFI is Source_File_Index;
283 System_Source_File_Index : SFI;
284 -- The file system.ads is always read by the compiler to determine the
285 -- settings of the target parameters in the private part of System. This
286 -- variable records the source file index of system.ads. Typically this
287 -- will be 1 since system.ads is read first.
289 function Debug_Source_Name (S : SFI) return File_Name_Type;
290 -- WARNING: There is a matching C declaration of this subprogram in fe.h
292 function File_Name (S : SFI) return File_Name_Type;
293 function File_Type (S : SFI) return Type_Of_File;
294 function First_Mapped_Line (S : SFI) return Logical_Line_Number;
295 function Full_Debug_Name (S : SFI) return File_Name_Type;
296 function Full_File_Name (S : SFI) return File_Name_Type;
297 function Full_Ref_Name (S : SFI) return File_Name_Type;
298 function Identifier_Casing (S : SFI) return Casing_Type;
299 function Inlined_Body (S : SFI) return Boolean;
300 function Inherited_Pragma (S : SFI) return Boolean;
301 function Inlined_Call (S : SFI) return Source_Ptr;
302 function Instance (S : SFI) return Instance_Id;
303 function Keyword_Casing (S : SFI) return Casing_Type;
304 function Last_Source_Line (S : SFI) return Physical_Line_Number;
305 function License (S : SFI) return License_Type;
306 function Num_SRef_Pragmas (S : SFI) return Nat;
307 function Reference_Name (S : SFI) return File_Name_Type;
308 function Source_Checksum (S : SFI) return Word;
309 function Source_First (S : SFI) return Source_Ptr;
310 function Source_Last (S : SFI) return Source_Ptr;
311 function Source_Text (S : SFI) return Source_Buffer_Ptr;
312 function Template (S : SFI) return Source_File_Index;
313 function Unit (S : SFI) return Unit_Number_Type;
314 function Time_Stamp (S : SFI) return Time_Stamp_Type;
316 procedure Set_Keyword_Casing (S : SFI; C : Casing_Type);
317 procedure Set_Identifier_Casing (S : SFI; C : Casing_Type);
318 procedure Set_License (S : SFI; L : License_Type);
319 procedure Set_Unit (S : SFI; U : Unit_Number_Type);
321 function Last_Source_File return Source_File_Index;
322 -- Index of last source file table entry
324 function Num_Source_Files return Nat;
325 -- Number of source file table entries
327 procedure Initialize;
328 -- Initialize internal tables
331 -- Lock internal tables
334 -- Unlock internal tables
336 Main_Source_File : Source_File_Index := No_Source_File;
337 -- This is set to the source file index of the main unit
339 -----------------------
340 -- Checksum Handling --
341 -----------------------
343 -- As a source file is scanned, a checksum is computed by taking all the
344 -- non-blank characters in the file, excluding comment characters, the
345 -- minus-minus sequence starting a comment, and all control characters
348 -- The checksum algorithm used is the standard CRC-32 algorithm, as
349 -- implemented by System.CRC32, except that we do not bother with the
350 -- final XOR with all 1 bits.
352 -- This algorithm ensures that the checksum includes all semantically
353 -- significant aspects of the program represented by the source file,
354 -- but is insensitive to layout, presence or contents of comments, wide
355 -- character representation method, or casing conventions outside strings.
357 -- Scans.Checksum is initialized appropriately at the start of scanning
358 -- a file, and copied into the Source_Checksum field of the file table
359 -- entry when the end of file is encountered.
361 -------------------------------------
362 -- Handling Generic Instantiations --
363 -------------------------------------
365 -- As described in Sem_Ch12, a generic instantiation involves making a
366 -- copy of the tree of the generic template. The source locations in
367 -- this tree directly reference the source of the template. However, it
368 -- is also possible to find the location of the instantiation.
370 -- This is achieved as follows. When an instantiation occurs, a new entry
371 -- is made in the source file table. The Source_Text of the instantiation
372 -- points to the same Source_Buffer as the Source_Text of the template, but
373 -- with different bounds. The separate range of Sloc values avoids
374 -- confusion, and means that the Sloc values can still be used to uniquely
375 -- identify the source file table entry. See Set_Dope below for the
376 -- low-level trickery that allows two different pointers to point at the
377 -- same array, but with different bounds.
379 -- The Instantiation_Id field of this source file index entry, set
380 -- to No_Instance_Id for normal entries, instead contains a value that
381 -- uniquely identifies a particular instantiation, and the associated
382 -- entry in the Instances table. The source location of the instantiation
383 -- can be retrieved using function Instantiation below. In the case of
384 -- nested instantiations, the Instances table can be used to trace the
385 -- complete chain of nested instantiations.
387 -- Two routines are used to build the special instance entries in the
388 -- source file table. Create_Instantiation_Source is first called to build
389 -- the virtual source table entry for the instantiation, and then the
390 -- Sloc values in the copy are adjusted using Adjust_Instantiation_Sloc.
391 -- See child unit Sinput.L for details on these two routines.
394 with procedure Process (Id : Instance_Id; Inst_Sloc : Source_Ptr);
395 procedure Iterate_On_Instances;
396 -- Execute Process for each entry in the instance table
398 function Instantiation (S : SFI) return Source_Ptr;
399 -- For a source file entry that represents an inlined body, source location
400 -- of the inlined call. For a source file entry that represents an
401 -- inherited pragma, source location of the declaration to which the
402 -- overriding subprogram for the inherited pragma is attached. Otherwise,
403 -- for a source file entry that represents a generic instantiation, source
404 -- location of the instantiation. Returns No_Location in all other cases.
410 Current_Source_File : Source_File_Index := No_Source_File;
411 -- Source_File table index of source file currently being scanned.
412 -- Initialized so that some tools (such as gprbuild) can be built with
413 -- -gnatVa and pragma Initialize_Scalars without problems.
415 Current_Source_Unit : Unit_Number_Type;
416 -- Unit number of source file currently being scanned. The special value
417 -- of No_Unit indicates that the configuration pragma file is currently
418 -- being scanned (this has no entry in the unit table).
420 Source_gnat_adc : Source_File_Index := No_Source_File;
421 -- This is set if a gnat.adc file is present to reference this file
423 Source : Source_Buffer_Ptr;
424 -- Current source (copy of Source_File.Table (Current_Source_Unit).Source)
426 -----------------------------------------
427 -- Handling of Source Line Terminators --
428 -----------------------------------------
430 -- In this section we discuss in detail the issue of terminators used to
431 -- terminate source lines. The RM says that one or more format effectors
432 -- (other than horizontal tab) end a source line, and defines the set of
433 -- such format effectors, but does not talk about exactly how they are
434 -- represented in the source program (since in general the RM is not in
435 -- the business of specifying source program formats).
437 -- The type Types.Line_Terminator is defined as a subtype of Character
438 -- that includes CR/LF/VT/FF. The most common line enders in practice
439 -- are CR (some MAC systems), LF (Unix systems), and CR/LF (DOS/Windows
440 -- systems). Any of these sequences is recognized as ending a physical
441 -- source line, and if multiple such terminators appear (e.g. LF/LF),
442 -- then we consider we have an extra blank line.
444 -- VT and FF are recognized as terminating source lines, but they are
445 -- considered to end a logical line instead of a physical line, so that
446 -- the line numbering ignores such terminators. The use of VT and FF is
447 -- mandated by the standard, and correctly handled in a conforming manner
448 -- by GNAT, but their use is not recommended.
450 -- In addition to the set of characters defined by the type in Types, in
451 -- wide character encoding, then the codes returning True for a call to
452 -- System.UTF_32.Is_UTF_32_Line_Terminator are also recognized as ending a
453 -- source line. This includes the standard codes defined above in addition
454 -- to NEL (NEXT LINE), LINE SEPARATOR and PARAGRAPH SEPARATOR. Again, as in
455 -- the case of VT and FF, the standard requires we recognize these as line
456 -- terminators, but we consider them to be logical line terminators. The
457 -- only physical line terminators recognized are the standard ones (CR,
460 -- However, we do not recognize the NEL (16#85#) character as having the
461 -- significance of an end of line character when operating in normal 8-bit
462 -- Latin-n input mode for the compiler. Instead the rule in this mode is
463 -- that all upper half control codes (16#80# .. 16#9F#) are illegal if they
464 -- occur in program text, and are ignored if they appear in comments.
466 -- First, note that this behavior is fully conforming with the standard.
467 -- The standard has nothing whatever to say about source representation
468 -- and implementations are completely free to make there own rules. In
469 -- this case, in 8-bit mode, GNAT decides that the 16#0085# character is
470 -- not a representation of the NEL character, even though it looks like it.
471 -- If you have NEL's in your program, which you expect to be treated as
472 -- end of line characters, you must use a wide character encoding such as
473 -- UTF-8 for this code to be recognized.
475 -- Second, an explanation of why we take this slightly surprising choice.
476 -- We have never encountered anyone actually using the NEL character to
477 -- end lines. One user raised the issue as a result of some experiments,
478 -- but no one has ever submitted a program encoded this way, in any of
479 -- the possible encodings. It seems that even when using wide character
480 -- codes extensively, the normal approach is to use standard line enders
481 -- (LF or CR/LF). So the failure to recognize NEL in this mode seems to
482 -- have no practical downside.
484 -- Moreover, what we have seen in a significant number of programs from
485 -- multiple sources is the practice of writing all program text in lower
486 -- half (ASCII) form, but using UTF-8 encoded wide characters freely in
487 -- comments, where the comments are terminated by normal line endings
488 -- (LF or CR/LF). The comments do not contain NEL codes, but they can and
489 -- do contain other UTF-8 encoding sequences where one of the bytes is the
490 -- NEL code. Now such programs can of course be compiled in UTF-8 mode,
491 -- but in practice they also compile fine in standard 8-bit mode without
492 -- specifying a character encoding. Since this is common practice, it would
493 -- be a significant upwards incompatibility to recognize NEL in 8-bit mode.
499 procedure Backup_Line (P : in out Source_Ptr);
500 -- Back up the argument pointer to the start of the previous line. On
501 -- entry, P points to the start of a physical line in the source buffer.
502 -- On return, P is updated to point to the start of the previous line.
503 -- The caller has checked that a Line_Terminator character precedes P so
504 -- that there definitely is a previous line in the source buffer.
506 procedure Build_Location_String
507 (Buf : in out Bounded_String;
509 -- This function builds a string literal of the form "name:line", where
510 -- name is the file name corresponding to Loc, and line is the line number.
511 -- If instantiations are involved, additional suffixes of the same form are
512 -- appended after the separating string " instantiated at ". The returned
513 -- string is appended to Buf.
515 function Build_Location_String (Loc : Source_Ptr) return String;
516 -- Functional form returning a String
518 procedure Check_For_BOM;
519 -- Check if the current source starts with a BOM. Scan_Ptr needs to be at
520 -- the start of the current source. If the current source starts with a
521 -- recognized BOM, then some flags such as Wide_Character_Encoding_Method
522 -- are set accordingly, and the Scan_Ptr on return points past this BOM.
523 -- An error message is output and Unrecoverable_Error raised if an
524 -- unrecognized BOM is detected. The call has no effect if no BOM is found.
526 function Get_Column_Number (P : Source_Ptr) return Column_Number;
527 -- The ones-origin column number of the specified Source_Ptr value is
528 -- determined and returned. Tab characters if present are assumed to
529 -- represent the standard 1,9,17.. spacing pattern.
531 -- WARNING: There is a matching C declaration of this subprogram in fe.h
533 function Get_Logical_Line_Number
534 (P : Source_Ptr) return Logical_Line_Number;
535 -- The line number of the specified source position is obtained by
536 -- doing a binary search on the source positions in the lines table
537 -- for the unit containing the given source position. The returned
538 -- value is the logical line number, already adjusted for the effect
539 -- of source reference pragmas. If P refers to the line of a source
540 -- reference pragma itself, then No_Line is returned. If no source
541 -- reference pragmas have been encountered, the value returned is
542 -- the same as the physical line number.
544 -- WARNING: There is a matching C declaration of this subprogram in fe.h
546 function Get_Logical_Line_Number_Img
547 (P : Source_Ptr) return String;
548 -- Same as above function, but returns the line number as a string of
549 -- decimal digits, with no leading space. Destroys Name_Buffer.
551 function Get_Physical_Line_Number
552 (P : Source_Ptr) return Physical_Line_Number;
553 -- The line number of the specified source position is obtained by
554 -- doing a binary search on the source positions in the lines table
555 -- for the unit containing the given source position. The returned
556 -- value is the physical line number in the source being compiled.
558 function Get_Source_File_Index (S : Source_Ptr) return Source_File_Index;
559 pragma Inline (Get_Source_File_Index);
560 -- Return file table index of file identified by given source pointer
561 -- value. This call must always succeed, since any valid source pointer
562 -- value belongs to some previously loaded source file.
564 -- WARNING: There is a matching C declaration of this subprogram in fe.h
566 function Instantiation_Depth (S : Source_Ptr) return Nat;
567 -- Determine instantiation depth for given Sloc value. A value of
568 -- zero means that the given Sloc is not in an instantiation.
570 function Line_Start (P : Source_Ptr) return Source_Ptr;
571 -- Finds the source position of the start of the line containing the
572 -- given source location.
575 (L : Physical_Line_Number;
576 S : Source_File_Index) return Source_Ptr;
577 -- Finds the source position of the start of the given line in the
578 -- given source file, using a physical line number to identify the line.
580 function Num_Source_Lines (S : Source_File_Index) return Nat;
581 -- Returns the number of source lines (this is equivalent to reading
582 -- the value of Last_Source_Line, but returns Nat rather than a
583 -- physical line number).
585 procedure Register_Source_Ref_Pragma
586 (File_Name : File_Name_Type;
587 Stripped_File_Name : File_Name_Type;
589 Line_After_Pragma : Physical_Line_Number);
590 -- Register a source reference pragma, the parameter File_Name is the
591 -- file name from the pragma, and Stripped_File_Name is this name with
592 -- the directory information stripped. Both these parameters are set
593 -- to No_Name if no file name parameter was given in the pragma.
594 -- (which can only happen for the second and subsequent pragmas).
595 -- Mapped_Line is the line number parameter from the pragma, and
596 -- Line_After_Pragma is the physical line number of the line that
597 -- follows the line containing the Source_Reference pragma.
599 function Original_Location (S : Source_Ptr) return Source_Ptr;
600 -- Given a source pointer S, returns the corresponding source pointer
601 -- value ignoring instantiation copies. For locations that do not
602 -- correspond to instantiation copies of templates, the argument is
603 -- returned unchanged. For locations that do correspond to copies of
604 -- templates from instantiations, the location within the original
605 -- template is returned. This is useful in canonicalizing locations.
607 function Instantiation_Location (S : Source_Ptr) return Source_Ptr;
608 pragma Inline (Instantiation_Location);
609 -- Given a source pointer S, returns the corresponding source pointer
610 -- value of the instantiation if this location is within an instance.
611 -- If S is not within an instance, then this returns No_Location.
613 function Comes_From_Inlined_Body (S : Source_Ptr) return Boolean;
614 pragma Inline (Comes_From_Inlined_Body);
615 -- Given a source pointer S, returns whether it comes from an inlined body.
616 -- This allows distinguishing these source pointers from those that come
617 -- from instantiation of generics, since Instantiation_Location returns a
618 -- valid location in both cases.
620 function Comes_From_Inherited_Pragma (S : Source_Ptr) return Boolean;
621 pragma Inline (Comes_From_Inherited_Pragma);
622 -- Given a source pointer S, returns whether it comes from an inherited
623 -- pragma. This allows distinguishing these source pointers from those
624 -- that come from instantiation of generics, since Instantiation_Location
625 -- returns a valid location in both cases.
627 function Top_Level_Location (S : Source_Ptr) return Source_Ptr;
628 -- Given a source pointer S, returns the argument unchanged if it is
629 -- not in an instantiation. If S is in an instantiation, then it returns
630 -- the location of the top level instantiation, i.e. the outer level
631 -- instantiation in the nested case.
633 function Physical_To_Logical
634 (Line : Physical_Line_Number;
635 S : Source_File_Index) return Logical_Line_Number;
636 -- Given a physical line number in source file whose source index is S,
637 -- return the corresponding logical line number. If the physical line
638 -- number is one containing a Source_Reference pragma, the result will
639 -- be No_Line_Number.
641 procedure Skip_Line_Terminators
642 (P : in out Source_Ptr;
643 Physical : out Boolean);
644 -- On entry, P points to a line terminator that has been encountered,
645 -- which is one of FF,LF,VT,CR or a wide character sequence whose value is
646 -- in category Separator,Line or Separator,Paragraph. P points just past
647 -- the character that was scanned. The purpose of this routine is to
648 -- distinguish physical and logical line endings. A physical line ending
651 -- CR on its own (MAC System 7)
652 -- LF on its own (Unix and unix-like systems)
653 -- CR/LF (DOS, Windows)
654 -- Wide character in Separator,Line or Separator,Paragraph category
656 -- Note: we no longer recognize LF/CR (which we did in some earlier
657 -- versions of GNAT. The reason for this is that this sequence is not
658 -- used and recognizing it generated confusion. For example given the
659 -- sequence LF/CR/LF we were interpreting that as (LF/CR) ending the
660 -- first line and a blank line ending with CR following, but it is
661 -- clearly better to interpret this as LF, with a blank line terminated
662 -- by CR/LF, given that LF and CR/LF are both in common use, but no
663 -- system we know of uses LF/CR.
665 -- A logical line ending (that is not a physical line ending) is one of:
670 -- On return, P is bumped past the line ending sequence (one of the above
671 -- seven possibilities). Physical is set to True to indicate that a
672 -- physical end of line was encountered, in which case this routine also
673 -- makes sure that the lines table for the current source file has an
674 -- appropriate entry for the start of the new physical line.
676 procedure Sloc_Range (N : Node_Id; Min, Max : out Source_Ptr);
677 -- Given a node, returns the minimum and maximum source locations of any
678 -- node in the syntactic subtree for the node. This is not quite the same
679 -- as the locations of the first and last token in the node construct
680 -- because parentheses at the outer level do not have a recorded Sloc.
682 -- Note: At each step of the tree traversal, we make sure to go back to
683 -- the Original_Node, since this function is concerned about original
684 -- (source) locations.
686 -- Note: if the tree for the expression contains no "real" Sloc values,
687 -- i.e. values > No_Location, then both Min and Max are set to
688 -- Sloc (Original_Node (N)).
690 function Source_Offset (S : Source_Ptr) return Nat;
691 -- Returns the zero-origin offset of the given source location from the
692 -- start of its corresponding unit. This is used for creating canonical
693 -- names in some situations.
695 procedure Write_Location (P : Source_Ptr);
696 -- Writes out a string of the form fff:nn:cc, where fff, nn, cc are the
697 -- file name, line number and column corresponding to the given source
698 -- location. No_Location and Standard_Location appear as the strings
699 -- <no location> and <standard location>. If the location is within an
700 -- instantiation, then the instance location is appended, enclosed in
701 -- square brackets (which can nest if necessary). Note that this routine
702 -- is used only for internal compiler debugging output purposes (which
703 -- is why the somewhat cryptic use of brackets is acceptable).
705 procedure wl (P : Source_Ptr);
706 pragma Export (Ada, wl);
707 -- Equivalent to Write_Location (P); Write_Eol; for calls from GDB
709 procedure Write_Time_Stamp (S : Source_File_Index);
710 -- Writes time stamp of specified file in YY-MM-DD HH:MM.SS format
712 procedure Clear_Source_File_Table;
713 -- This procedure frees memory allocated in the Source_File table (in the
714 -- private). It should only be used when it is guaranteed that all source
715 -- files that have been loaded so far will not be accessed before being
716 -- reloaded. It is intended for tools that parse several times sources,
717 -- to avoid memory leaks.
720 pragma Inline (File_Name);
721 pragma Inline (Full_File_Name);
722 pragma Inline (File_Type);
723 pragma Inline (Reference_Name);
724 pragma Inline (Full_Ref_Name);
725 pragma Inline (Debug_Source_Name);
726 pragma Inline (Full_Debug_Name);
727 pragma Inline (Instance);
728 pragma Inline (License);
729 pragma Inline (Num_SRef_Pragmas);
730 pragma Inline (First_Mapped_Line);
731 pragma Inline (Source_Text);
732 pragma Inline (Source_First);
733 pragma Inline (Source_Last);
734 pragma Inline (Time_Stamp);
735 pragma Inline (Source_Checksum);
736 pragma Inline (Last_Source_Line);
737 pragma Inline (Keyword_Casing);
738 pragma Inline (Identifier_Casing);
739 pragma Inline (Inlined_Call);
740 pragma Inline (Inlined_Body);
741 pragma Inline (Inherited_Pragma);
742 pragma Inline (Template);
743 pragma Inline (Unit);
745 pragma Inline (Set_Keyword_Casing);
746 pragma Inline (Set_Identifier_Casing);
748 pragma Inline (Last_Source_File);
749 pragma Inline (Num_Source_Files);
750 pragma Inline (Num_Source_Lines);
752 pragma Inline (Line_Start);
754 No_Instance_Id : constant Instance_Id := 0;
756 -------------------------
757 -- Source_Lines Tables --
758 -------------------------
760 type Lines_Table_Type is
761 array (Physical_Line_Number) of Source_Ptr;
762 -- Type used for lines table. The entries are indexed by physical line
763 -- numbers. The values are the starting Source_Ptr values for the start
764 -- of the corresponding physical line. Note that we make this a bogus
765 -- big array, sized as required, so that we avoid the use of fat pointers.
767 type Lines_Table_Ptr is access all Lines_Table_Type;
768 -- Type used for pointers to line tables
770 type Logical_Lines_Table_Type is
771 array (Physical_Line_Number) of Logical_Line_Number;
772 -- Type used for logical lines table. This table is used if a source
773 -- reference pragma is present. It is indexed by physical line numbers,
774 -- and contains the corresponding logical line numbers. An entry that
775 -- corresponds to a source reference pragma is set to No_Line_Number.
776 -- Note that we make this a bogus big array, sized as required, so that
777 -- we avoid the use of fat pointers.
779 type Logical_Lines_Table_Ptr is access all Logical_Lines_Table_Type;
780 -- Type used for pointers to logical line tables
782 -----------------------
783 -- Source_File Table --
784 -----------------------
786 -- See earlier descriptions for meanings of public fields
788 type Source_File_Record is record
789 File_Name : File_Name_Type;
790 Reference_Name : File_Name_Type;
791 Debug_Source_Name : File_Name_Type;
792 Full_Debug_Name : File_Name_Type;
793 Full_File_Name : File_Name_Type;
794 Full_Ref_Name : File_Name_Type;
795 Instance : Instance_Id;
796 Num_SRef_Pragmas : Nat;
797 First_Mapped_Line : Logical_Line_Number;
798 Source_Text : Source_Buffer_Ptr;
799 Source_First : Source_Ptr;
800 Source_Last : Source_Ptr;
801 Source_Checksum : Word;
802 Last_Source_Line : Physical_Line_Number;
803 Template : Source_File_Index;
804 Unit : Unit_Number_Type;
805 Time_Stamp : Time_Stamp_Type;
806 File_Type : Type_Of_File;
807 Inlined_Call : Source_Ptr;
808 Inlined_Body : Boolean;
809 Inherited_Pragma : Boolean;
810 License : License_Type;
811 Keyword_Casing : Casing_Type;
812 Identifier_Casing : Casing_Type;
814 -- The following fields are for internal use only (i.e. only in the
815 -- body of Sinput or its children, with no direct access by clients).
817 Sloc_Adjust : Source_Ptr;
818 -- A value to be added to Sloc values for this file to reference the
819 -- corresponding lines table. This is zero for the non-instantiation
820 -- case, and set so that the addition references the ultimate template
821 -- for the instantiation case. See Sinput-L for further details.
823 Lines_Table : Lines_Table_Ptr;
824 -- Pointer to lines table for this source. Updated as additional
825 -- lines are accessed using the Skip_Line_Terminators procedure.
826 -- Note: the lines table for an instantiation entry refers to the
827 -- original line numbers of the template see Sinput-L for details.
829 Logical_Lines_Table : Logical_Lines_Table_Ptr;
830 -- Pointer to logical lines table for this source. Non-null only if
831 -- a source reference pragma has been processed. Updated as lines
832 -- are accessed using the Skip_Line_Terminators procedure.
834 Lines_Table_Max : Physical_Line_Number;
835 -- Maximum subscript values for currently allocated Lines_Table
836 -- and (if present) the allocated Logical_Lines_Table. The value
837 -- Max_Source_Line gives the maximum used value, this gives the
838 -- maximum allocated value.
840 Index : Source_File_Index := 123456789; -- for debugging
843 -- The following representation clause ensures that the above record
844 -- has no holes. We do this so that when instances of this record are
845 -- written by Tree_Gen, we do not write uninitialized values to the file.
847 AS : constant Pos := Standard'Address_Size;
849 for Source_File_Record use record
850 File_Name at 0 range 0 .. 31;
851 Reference_Name at 4 range 0 .. 31;
852 Debug_Source_Name at 8 range 0 .. 31;
853 Full_Debug_Name at 12 range 0 .. 31;
854 Full_File_Name at 16 range 0 .. 31;
855 Full_Ref_Name at 20 range 0 .. 31;
856 Instance at 48 range 0 .. 31;
857 Num_SRef_Pragmas at 24 range 0 .. 31;
858 First_Mapped_Line at 28 range 0 .. 31;
859 Source_First at 32 range 0 .. 31;
860 Source_Last at 36 range 0 .. 31;
861 Source_Checksum at 40 range 0 .. 31;
862 Last_Source_Line at 44 range 0 .. 31;
863 Template at 52 range 0 .. 31;
864 Unit at 56 range 0 .. 31;
865 Time_Stamp at 60 range 0 .. 8 * Time_Stamp_Length - 1;
866 File_Type at 74 range 0 .. 7;
867 Inlined_Call at 88 range 0 .. 31;
868 Inlined_Body at 75 range 0 .. 0;
869 Inherited_Pragma at 75 range 1 .. 1;
870 License at 76 range 0 .. 7;
871 Keyword_Casing at 77 range 0 .. 7;
872 Identifier_Casing at 78 range 0 .. 15;
873 Sloc_Adjust at 80 range 0 .. 31;
874 Lines_Table_Max at 84 range 0 .. 31;
875 Index at 92 range 0 .. 31;
877 -- The following fields are pointers, so we have to specialize their
878 -- lengths using pointer size, obtained above as Standard'Address_Size.
879 -- Note that Source_Text is a fat pointer, so it has size = AS*2.
881 Source_Text at 96 range 0 .. AS * 2 - 1;
882 Lines_Table at 96 range AS * 2 .. AS * 3 - 1;
883 Logical_Lines_Table at 96 range AS * 3 .. AS * 4 - 1;
884 end record; -- Source_File_Record
886 for Source_File_Record'Size use 96 * 8 + AS * 4;
887 -- This ensures that we did not leave out any fields
889 package Source_File is new Table.Table
890 (Table_Component_Type => Source_File_Record,
891 Table_Index_Type => Source_File_Index,
892 Table_Low_Bound => 1,
893 Table_Initial => Alloc.Source_File_Initial,
894 Table_Increment => Alloc.Source_File_Increment,
895 Table_Name => "Source_File");
897 -- Auxiliary table containing source location of instantiations. Index 0
898 -- is used for code that does not come from an instance.
900 package Instances is new Table.Table
901 (Table_Component_Type => Source_Ptr,
902 Table_Index_Type => Instance_Id,
903 Table_Low_Bound => 0,
904 Table_Initial => Alloc.Source_File_Initial,
905 Table_Increment => Alloc.Source_File_Increment,
906 Table_Name => "Instances");
912 procedure Alloc_Line_Tables
913 (S : in out Source_File_Record;
915 -- Allocate or reallocate the lines table for the given source file so
916 -- that it can accommodate at least New_Max lines. Also allocates or
917 -- reallocates logical lines table if source ref pragmas are present.
919 procedure Add_Line_Tables_Entry
920 (S : in out Source_File_Record;
922 -- Increment line table size by one (reallocating the lines table if
923 -- needed) and set the new entry to contain the value P. Also bumps
924 -- the Source_Line_Count field. If source reference pragmas are
925 -- present, also increments logical lines table size by one, and
928 procedure Trim_Lines_Table (S : Source_File_Index);
929 -- Set lines table size for entry S in the source file table to
930 -- correspond to the current value of Num_Source_Lines, releasing
931 -- any unused storage. This is used by Sinput.L and Sinput.D.
933 procedure Set_Source_File_Index_Table (Xnew : Source_File_Index);
934 -- Sets entries in the Source_File_Index_Table for the newly created
935 -- Source_File table entry whose index is Xnew. The Source_First and
936 -- Source_Last fields of this entry must be set before the call.
937 -- See package body for details.
939 type Dope_Rec is record
940 First, Last : Source_Ptr'Base;
942 Dope_Rec_Size : constant := 2 * Source_Ptr'Base'Size;
943 for Dope_Rec'Size use Dope_Rec_Size;
944 for Dope_Rec'Alignment use Dope_Rec_Size / 8;
945 type Dope_Ptr is access all Dope_Rec;
948 (Src : System.Address; New_Dope : Dope_Ptr);
949 -- Src is the address of a variable of type Source_Buffer_Ptr, which is a
950 -- fat pointer. This sets the dope part of the fat pointer to point to the
951 -- specified New_Dope. This low-level processing is used to make the
952 -- Source_Text of an instance point to the same text as the template, but
953 -- with different bounds.
955 procedure Free_Dope (Src : System.Address);
956 -- Calls Unchecked_Deallocation on the dope part of the fat pointer Src
958 procedure Free_Source_Buffer (Src : in out Source_Buffer_Ptr);
959 -- Deallocates the source buffer
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