1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1998-2009, 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 for collecting and outputting cross-reference
29 with Einfo; use Einfo;
33 -------------------------------------------------------
34 -- Format of Cross-Reference Information in ALI File --
35 -------------------------------------------------------
37 -- Cross-reference sections follow the dependency section (D lines) in
38 -- an ALI file, so that they need not be read by gnatbind, gnatmake etc.
40 -- A cross reference section has a header of the form
42 -- X dependency-number filename
44 -- This header precedes xref information (entities/references from
45 -- the unit), identified by dependency number and file name. The
46 -- dependency number is the index into the generated D lines and
47 -- is ones origin (i.e. 2 = reference to second generated D line).
49 -- Note that the filename here will reflect the original name if
50 -- a Source_Reference pragma was encountered (since all line number
51 -- references will be with respect to the original file).
53 -- The lines following the header look like
55 -- line type col level entity renameref instref typeref overref ref ref
57 -- line is the line number of the referenced entity. The name of
58 -- the entity starts in column col. Columns are numbered from one,
59 -- and if horizontal tab characters are present, the column number
60 -- is computed assuming standard 1,9,17,.. tab stops. For example,
61 -- if the entity is the first token on the line, and is preceded
62 -- by space-HT-space, then the column would be column 10.
64 -- type is a single letter identifying the type of the entity.
65 -- See next section (Cross-Reference Entity Identifiers) for a
66 -- full list of the characters used).
68 -- col is the column number of the referenced entity
70 -- level is a single character that separates the col and
71 -- entity fields. It is an asterisk for a top level library
72 -- entity that is publicly visible, as well for an entity declared
73 -- in the visible part of a generic package, and space otherwise.
75 -- entity is the name of the referenced entity, with casing in
76 -- the canonical casing for the source file where it is defined.
78 -- renameref provides information on renaming. If the entity is
79 -- a package, object or overloadable entity which is declared by
80 -- a renaming declaration, and the renaming refers to an entity
81 -- with a simple identifier or expanded name, then renameref has
86 -- Here line:col give the reference to the identifier that
87 -- appears in the renaming declaration. Note that we never need
88 -- a file entry, since this identifier is always in the current
89 -- file in which the entity is declared. Currently, renameref
90 -- appears only for the simple renaming case. If the renaming
91 -- reference is a complex expressions, then renameref is omitted.
92 -- Here line/col give line/column as defined above.
94 -- instref is only present for package and subprogram instances.
95 -- The information in instref is the location of the point of
96 -- declaration of the generic parent unit. This part has the form:
100 -- without column information, on the reasonable assumption that
101 -- there is only one unit per line (the same assumption is made
102 -- in references to entities that are declared within instances,
105 -- typeref is the reference for a related type. This part is
106 -- optional. It is present for the following cases:
108 -- derived types (points to the parent type) LR=<>
109 -- access types (points to designated type) LR=()
110 -- array types (points to component type) LR=()
111 -- subtypes (points to ancestor type) LR={}
112 -- functions (points to result type) LR={}
113 -- enumeration literals (points to enum type) LR={}
114 -- objects and components (points to type) LR={}
116 -- For a type that implements multiple interfaces, there is an
117 -- entry of the form LR=<> for each of the interfaces appearing
118 -- in the type declaration. In the data structures of ali.ads,
119 -- the type that the entity extends (or the first interface if
120 -- there is no such type) is stored in Xref_Entity_Record.Tref*,
121 -- additional interfaces are stored in the list of references
122 -- with a special type of Interface_Reference.
124 -- For an array type, there is an entry of the form LR=<> for
125 -- each of the index types appearing in the type declaration.
126 -- The index types follow the entry for the component type.
127 -- In the data structures of ali.ads, however, the list of index
128 -- types are output in the list of references with a special
129 -- Rtype set to Array_Index_Reference.
131 -- In the above list LR shows the brackets used in the output,
132 -- which has one of the two following forms:
134 -- L file | line type col R user entity
135 -- L name-in-lower-case R standard entity
137 -- For the form for a user entity, file is the dependency number
138 -- of the file containing the declaration of the related type.
139 -- This number and the following vertical bar are omitted if the
140 -- relevant type is defined in the same file as the current entity.
141 -- The line, type, col are defined as previously described, and
142 -- specify the location of the relevant type declaration in the
143 -- referenced file. For the standard entity form, the name between
144 -- the brackets is the normal name of the entity in lower case.
146 -- overref is present for overriding operations (procedures and
147 -- functions), and provides information on the operation that it
148 -- overrides. This information has the format:
150 -- '<' file | line 'o' col '>'
152 -- file is the dependency number of the file containing the
153 -- declaration of the overridden operation. It and the following
154 -- vertical bar are omitted if the file is the same as that of
155 -- the overriding operation.
157 -- There may be zero or more ref entries on each line
159 -- file | line type col [...]
161 -- file is the dependency number of the file with the reference.
162 -- It and the following vertical bar are omitted if the file is
163 -- the same as the previous ref, and the refs for the current
164 -- file are first (and do not need a bar).
166 -- line is the line number of the reference
168 -- col is the column number of the reference, as defined above
172 -- c = completion of private or incomplete type
173 -- d = discriminant of type
176 -- i = implicit reference
177 -- k = implicit reference to parent unit in child unit
178 -- l = label on END line
180 -- o = own variable reference (SPARK only)
181 -- p = primitive operation
182 -- P = overriding primitive operation
184 -- R = subprogram reference in dispatching call
187 -- x = type extension
188 -- z = generic formal parameter
189 -- > = subprogram IN parameter
190 -- = = subprogram IN OUT parameter
191 -- < = subprogram OUT parameter
192 -- ^ = subprogram ACCESS parameter
194 -- b is used for spec entities that are repeated in a body,
195 -- including the unit (subprogram, package, task, protected
196 -- body, protected entry) name itself, and in the case of a
197 -- subprogram, the formals. This letter is also used for the
198 -- occurrence of entry names in accept statements. Such entities
199 -- are not considered to be definitions for cross-referencing
200 -- purposes, but rather are considered to be references to the
201 -- corresponding spec entities, marked with this special type.
203 -- c is similar to b but is used to mark the completion of a
204 -- private or incomplete type. As with b, the completion is not
205 -- regarded as a separate definition, but rather a reference to
206 -- the initial declaration, marked with this special type.
208 -- d is used to identify a discriminant of a type. If this is
209 -- an incomplete or private type with discriminants, the entry
210 -- denotes the occurrence of the discriminant in the partial view
211 -- which is also the point of definition of the discriminant.
212 -- The occurrence of the same discriminant in the full view is
213 -- a regular reference to it.
215 -- e is used to identify the end of a construct in the following
218 -- Block Statement end [block_IDENTIFIER];
219 -- Loop Statement end loop [loop_IDENTIFIER];
220 -- Package Specification end [[PARENT_UNIT_NAME .] IDENTIFIER];
221 -- Task Definition end [task_IDENTIFIER];
222 -- Protected Definition end [protected_IDENTIFIER];
223 -- Record Definition end record;
224 -- Enumeration Definition );
226 -- Note that 'e' entries are special in that they appear even
227 -- in referencing units (normally xref entries appear only
228 -- for references in the extended main source unit (see Lib) to
229 -- which the ali applies. But 'e' entries are really structural
230 -- and simply indicate where packages end. This information can
231 -- be used to reconstruct scope information for any entities
232 -- referenced from within the package. The line/column values
233 -- for these entries point to the semicolon ending the construct.
235 -- i is used to identify a reference to the entity in a generic
236 -- actual or in a default in a call. The node that denotes the
237 -- entity does not come from source, but it has the Sloc of the
238 -- source node that generates the implicit reference, and it is
239 -- useful to record this one.
241 -- k is another non-standard reference type, used to record a
242 -- reference from a child unit to its parent. For various cross-
243 -- referencing tools, we need a pointer from the xref entries for
244 -- the child to the parent. This is the opposite way round from
245 -- normal xref entries, since the reference is *from* the child
246 -- unit *to* the parent unit, yet appears in the xref entries for
247 -- the child. Consider this example:
254 -- The ali file for q-r.ads has these entries
260 -- 1K9*q 2e4 2|1r9 2r5
262 -- 1K11*r 1|1k9 2|2l7 2e8
264 -- Here the 2|1r9 entry appearing in the section for the parent
265 -- is the normal reference from the child to the parent. The 1k9
266 -- entry in the section for the child duplicates this information
267 -- but appears in the child rather than the parent.
269 -- l is used to identify the occurrence in the source of the
270 -- name on an end line. This is just a syntactic reference
271 -- which can be ignored for semantic purposes (such as call
272 -- graph construction). Again, in the case of an accept there
273 -- can be multiple l lines.
275 -- o is used for variables referenced from a SPARK 'own'
276 -- definition. In the SPARK language, it is allowed to use a
277 -- variable before its actual declaration.
279 -- p is used to mark a primitive operation of the given entity.
280 -- For example, if we have a type Tx, and a primitive operation
281 -- Pq of this type, then an entry in the list of references to
282 -- Tx will point to the declaration of Pq. Note that this entry
283 -- type is unusual because it an implicit rather than explicit,
284 -- and the name of the reference does not match the name of the
285 -- entity for which a reference is generated. These entries are
286 -- generated only for entities declared in the extended main
287 -- source unit (main unit itself, its separate spec (if any).
288 -- and all subunits (considered recursively).
290 -- If the primitive operation overrides an inherited primitive
291 -- operation of the parent type, the letter 'P' is used in the
292 -- corresponding entry.
294 -- R is used to mark a dispatching call. The reference is to
295 -- the specification of the primitive operation of the root
296 -- type when the call has a controlling argument in its class.
298 -- t is similar to e. It identifies the end of a corresponding
299 -- body (such a reference always links up with a b reference)
301 -- Subprogram Body end [DESIGNATOR];
302 -- Package Body end [[PARENT_UNIT_NAME .] IDENTIFIER];
303 -- Task Body end [task_IDENTIFIER];
304 -- Entry Body end [entry_IDENTIFIER];
305 -- Protected Body end [protected_IDENTIFIER]
306 -- Accept Statement end [entry_IDENTIFIER]];
308 -- Note that in the case of accept statements, there can
309 -- be multiple b and t entries for the same entity.
311 -- x is used to identify the reference as the entity from which
312 -- a tagged type is extended. This allows immediate access to
313 -- the parent of a tagged type.
315 -- z is used on the cross-reference line for a generic unit, to
316 -- mark the definition of a generic formal of the unit.
317 -- This entry type is similar to 'k' and 'p' in that it is an
318 -- implicit reference for an entity with a different name.
320 -- The characters >, <. =, and ^ are used on the cross-reference
321 -- line for a subprogram, to denote formal parameters and their
322 -- modes. As with the 'z' and 'p' entries, each such entry is
323 -- an implicit reference to an entity with a different name.
325 -- [..] is used for generic instantiation references. These
326 -- references are present only if the entity in question is
327 -- a generic entity, and in that case the [..] contains the
328 -- reference for the instantiation. In the case of nested
329 -- instantiations, this can be nested [...[...[...]]] etc.
330 -- The reference is of the form [file|line] no column is
331 -- present since it is assumed that only one instantiation
332 -- appears on a single source line. Note that the appearance
333 -- of file numbers in such references follows the normal
334 -- rules (present only if needed, and resets the current
335 -- file for subsequent references).
339 -- 44B5*Flag_Type{boolean} 5r23 6m45 3|9r35 11r56
341 -- This line gives references for the publicly visible Boolean
342 -- type Flag_Type declared on line 44, column 5. There are four
345 -- a reference on line 5, column 23 of the current file
347 -- a modification on line 6, column 45 of the current file
349 -- a reference on line 9, column 35 of unit number 3
351 -- a reference on line 11, column 56 of unit number 3
353 -- 2U13 p3=2:35 5b13 8r4 12r13 12t15
355 -- This line gives references for the non-publicly visible
356 -- procedure p3 declared on line 2, column 13. This procedure
357 -- renames the procedure whose identifier reference is at
358 -- line 2 column 35. There are four references:
360 -- the corresponding body entity at line 5, column 13,
361 -- of the current file.
363 -- a reference (e.g. a call) at line 8 column 4 of the
364 -- of the current file.
366 -- the END line of the body has an explicit reference to
367 -- the name of the procedure at line 12, column 13.
369 -- the body ends at line 12, column 15, just past this label
371 -- 16I9*My_Type<2|4I9> 18r8
373 -- This line gives references for the publicly visible Integer
374 -- derived type My_Type declared on line 16, column 9. It also
375 -- gives references to the parent type declared in the unit
376 -- number 2 on line 4, column 9. There is one reference:
378 -- a reference (e.g. a variable declaration) at line 18 column
379 -- 4 of the current file.
381 -- 10I3*Genv{integer} 3|4I10[6|12]
383 -- This line gives a reference for the entity Genv in a generic
384 -- package. The reference in file 3, line 4, col 10, refers to
385 -- an instance of the generic where the instantiation can be
386 -- found in file 6 at line 12.
388 -- Continuation lines are used if the reference list gets too long,
389 -- a continuation line starts with a period, and then has references
390 -- continuing from the previous line. The references are sorted first
391 -- by unit, then by position in the source.
393 -- Note on handling of generic entities. The cross-reference is oriented
394 -- towards source references, so the entities in a generic instantiation
395 -- are not considered distinct from the entities in the template. All
396 -- definitions and references from generic instantiations are suppressed,
397 -- since they will be generated from the template. Any references to
398 -- entities in a generic instantiation from outside the instantiation
399 -- are considered to be references to the original template entity.
401 ----------------------------------------
402 -- Cross-Reference Entity Identifiers --
403 ----------------------------------------
405 -- In the cross-reference section of the ali file, entity types are
406 -- identified by a single letter, indicating the entity type. The
407 -- following table indicates the letter. A space for an entry is
408 -- used for entities that do not appear in the cross-reference table.
410 -- For objects, the character * appears in this table. In the xref
411 -- listing, this character is replaced by the lower case letter that
412 -- corresponds to the type of the object. For example, if a variable
413 -- is of a Float type, then, since the type is represented by an
414 -- upper case F, the object would be represented by a lower case f.
416 -- A special exception is the case of booleans, whose entities are
417 -- normal E_Enumeration_Type or E_Enumeration_Subtype entities, but
418 -- which appear as B/b in the xref lines, rather than E/e.
420 -- For private types, the character + appears in the table. In this
421 -- case the kind of the underlying type is used, if available, to
422 -- determine the character to use in the xref listing. The listing
423 -- will still include a '+' for a generic private type, for example,
424 -- but will retain the '*' for an object or formal parameter of such
427 -- For subprograms, the characters 'U' and 'V' appear in the table,
428 -- indicating procedures and functions. If the operation is abstract,
429 -- these letters are replaced in the xref by 'x' and 'y' respectively.
431 Xref_Entity_Letters : array (Entity_Kind) of Character :=
436 E_Discriminant => '*',
438 E_Loop_Parameter => '*',
439 E_In_Parameter => '*',
440 E_Out_Parameter => '*',
441 E_In_Out_Parameter => '*',
442 E_Generic_In_Out_Parameter => '*',
444 E_Generic_In_Parameter => '*',
445 E_Named_Integer => 'N',
447 E_Enumeration_Type => 'E', -- B for boolean
448 E_Enumeration_Subtype => 'E', -- B for boolean
450 E_Signed_Integer_Type => 'I',
451 E_Signed_Integer_Subtype => 'I',
452 E_Modular_Integer_Type => 'M',
453 E_Modular_Integer_Subtype => 'M',
454 E_Ordinary_Fixed_Point_Type => 'O',
456 E_Ordinary_Fixed_Point_Subtype => 'O',
457 E_Decimal_Fixed_Point_Type => 'D',
458 E_Decimal_Fixed_Point_Subtype => 'D',
459 E_Floating_Point_Type => 'F',
460 E_Floating_Point_Subtype => 'F',
462 E_Access_Type => 'P',
463 E_Access_Subtype => 'P',
464 E_Access_Attribute_Type => 'P',
465 E_Allocator_Type => ' ',
466 E_General_Access_Type => 'P',
468 E_Access_Subprogram_Type => 'P',
469 E_Access_Protected_Subprogram_Type => 'P',
470 E_Anonymous_Access_Subprogram_Type => ' ',
471 E_Anonymous_Access_Protected_Subprogram_Type => ' ',
472 E_Anonymous_Access_Type => ' ',
475 E_Array_Subtype => 'A',
476 E_String_Type => 'S',
477 E_String_Subtype => 'S',
478 E_String_Literal_Subtype => ' ',
480 E_Class_Wide_Type => 'C',
481 E_Class_Wide_Subtype => 'C',
482 E_Record_Type => 'R',
483 E_Record_Subtype => 'R',
484 E_Record_Type_With_Private => 'R',
486 E_Record_Subtype_With_Private => 'R',
487 E_Private_Type => '+',
488 E_Private_Subtype => '+',
489 E_Limited_Private_Type => '+',
490 E_Limited_Private_Subtype => '+',
492 E_Incomplete_Type => '+',
493 E_Incomplete_Subtype => '+',
495 E_Task_Subtype => 'T',
496 E_Protected_Type => 'W',
498 E_Protected_Subtype => 'W',
499 E_Exception_Type => ' ',
500 E_Subprogram_Type => ' ',
501 E_Enumeration_Literal => 'n',
507 E_Entry_Family => 'Y',
510 E_Entry_Index_Parameter => '*',
512 E_Generic_Function => 'v',
513 E_Generic_Package => 'k',
514 E_Generic_Procedure => 'u',
518 E_Return_Statement => ' ',
521 -- The following entities are not ones to which we gather
522 -- cross-references, since it does not make sense to do so
523 -- (e.g. references to a package are to the spec, not the body)
524 -- Indeed the occurrence of the body entity is considered to
525 -- be a reference to the spec entity.
527 E_Package_Body => ' ',
528 E_Protected_Object => ' ',
529 E_Protected_Body => ' ',
531 E_Subprogram_Body => ' ');
533 -- The following table is for information purposes. It shows the
534 -- use of each character appearing as an entity type.
536 -- letter lower case usage UPPER CASE USAGE
538 -- a array object (except string) array type (except string)
539 -- b Boolean object Boolean type
540 -- c class-wide object class-wide type
541 -- d decimal fixed-point object decimal fixed-point type
542 -- e non-Boolean enumeration object non_Boolean enumeration type
543 -- f floating-point object floating-point type
544 -- g (unused) (unused)
545 -- h Interface (Ada 2005) Abstract type
546 -- i signed integer object signed integer type
547 -- j (unused) (unused)
548 -- k generic package package
549 -- l label on loop label on statement
550 -- m modular integer object modular integer type
551 -- n enumeration literal named number
552 -- o ordinary fixed-point object ordinary fixed-point type
553 -- p access object access type
554 -- q label on block (unused)
555 -- r record object record type
556 -- s string object string type
557 -- t task object task type
558 -- u generic procedure procedure
559 -- v generic function or operator function or operator
560 -- w protected object protected type
561 -- x abstract procedure exception
562 -- y abstract function entry or entry family
563 -- z generic formal parameter (unused)
565 --------------------------------------
566 -- Handling of Imported Subprograms --
567 --------------------------------------
569 -- If a pragma Import or Interface applies to a subprogram, the
570 -- pragma is the completion of the subprogram. This is noted in
571 -- the ALI file by making the occurrence of the subprogram in the
572 -- pragma into a body reference ('b') and by including the external
573 -- name of the subprogram and its language, bracketed by '<' and '>'
574 -- in that reference. For example:
576 -- 3U13*elsewhere 4b<c,there>21
578 -- indicates that procedure elsewhere, declared at line 3, has a
579 -- pragma Import at line 4, that its body is in C, and that the link
580 -- name as given in the pragma is "there".
586 procedure Generate_Definition (E : Entity_Id);
587 -- Records the definition of an entity
589 procedure Generate_Operator_Reference
592 -- Node N is an operator node, whose entity has been set. If this entity
593 -- is a user defined operator (i.e. an operator not defined in package
594 -- Standard), then a reference to the operator is recorded at node N.
595 -- T is the operand type of the operator. A reference to the operator
596 -- is an implicit reference to the type, and that needs to be recorded
597 -- to avoid spurious warnings on unused entities, when the operator is
598 -- a renaming of a predefined operator.
600 procedure Generate_Reference
603 Typ : Character := 'r';
604 Set_Ref : Boolean := True;
605 Force : Boolean := False);
606 -- This procedure is called to record a reference. N is the location
607 -- of the reference and E is the referenced entity. Typ is one of:
610 -- 'c' completion of incomplete or private type (see below)
611 -- 'e' end of construct
612 -- 'i' implicit reference
613 -- 'l' label on end line
615 -- 'p' primitive operation
616 -- 'r' standard reference
618 -- 'x' type extension
619 -- ' ' dummy reference (see below)
621 -- Note: all references to incomplete or private types are to the
622 -- original (incomplete or private type) declaration. The full
623 -- declaration is treated as a reference with type 'c'.
625 -- Note: all references to packages or subprograms are to the entity
626 -- for the spec. The entity in the body is treated as a reference
627 -- with type 'b'. Similar handling for references to subprogram formals.
629 -- The call has no effect if N is not in the extended main source unit
630 -- This check is omitted for type 'e' references (where it is useful to
631 -- have structural scoping information for other than the main source),
632 -- and for 'p' (since we want to pick up inherited primitive operations
633 -- that are defined in other packages).
635 -- The call also has no effect if any of the following conditions hold:
637 -- cross-reference collection is disabled
638 -- entity does not come from source (and Force is False)
639 -- reference does not come from source (and Force is False)
640 -- the entity is not one for which xrefs are appropriate
641 -- the type letter is blank
642 -- the node N is not an identifier, defining identifier, or expanded name
643 -- the type is 'p' and the entity is not in the extended main source
645 -- If all these conditions are met, then the Is_Referenced flag of E is set
646 -- (unless Set_Ref is False) and a cross-reference entry is recorded for
647 -- later output when Output_References is called.
649 -- Note: the dummy space entry is for the convenience of some callers,
650 -- who find it easier to pass a space to suppress the entry than to do
651 -- a specific test. The call has no effect if the type is a space.
653 -- The parameter Set_Ref is normally True, and indicates that in addition
654 -- to generating a cross-reference, the Referenced flag of the specified
655 -- entity should be set. If this parameter is False, then setting of the
656 -- Referenced flag is inhibited.
658 -- The parameter Force is set to True to force a reference to be generated
659 -- even if Comes_From_Source is false. This is used for certain implicit
660 -- references, and also for end label references.
662 procedure Generate_Reference_To_Formals (E : Entity_Id);
663 -- Add a reference to the definition of each formal on the line for
666 procedure Generate_Reference_To_Generic_Formals (E : Entity_Id);
667 -- Add a reference to the definition of each generic formal on the line
668 -- for a generic unit.
670 procedure Output_References;
671 -- Output references to the current ali file
673 procedure Initialize;
674 -- Initialize internal tables
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