------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- L I B . X R E F -- -- -- -- S p e c -- -- -- -- Copyright (C) 1998-2022, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package contains for collecting and outputting cross-reference -- information. with Einfo.Entities; use Einfo.Entities; with SPARK_Xrefs; package Lib.Xref is ------------------------------------------------------- -- Format of Cross-Reference Information in ALI File -- ------------------------------------------------------- -- Cross-reference sections follow the dependency section (D lines) in -- an ALI file, so that they need not be read by gnatbind, gnatmake etc. -- A cross reference section has a header of the form -- X dependency-number filename -- This header precedes xref information (entities/references from -- the unit), identified by dependency number and file name. The -- dependency number is the index into the generated D lines and -- is ones origin (e.g. 2 = reference to second generated D line). -- Note that the filename here will reflect the original name if -- a Source_Reference pragma was encountered (since all line number -- references will be with respect to the original file). -- The lines following the header look like -- line type col level entity renameref instref typeref overref ref ref -- line is the line number of the referenced entity. The name of -- the entity starts in column col. Columns are numbered from one, -- and if horizontal tab characters are present, the column number -- is computed assuming standard 1,9,17,.. tab stops. For example, -- if the entity is the first token on the line, and is preceded -- by space-HT-space, then the column would be column 10. -- type is a single letter identifying the type of the entity. See -- next section (Cross-Reference Entity Identifiers) for a full list -- of the characters used). -- col is the column number of the referenced entity -- level is a single character that separates the col and entity -- fields. It is an asterisk (*) for a top level library entity that -- is publicly visible, as well for an entity declared in the visible -- part of a generic package, the plus sign (+) for a C/C++ static -- entity, and space otherwise. -- entity is the name of the referenced entity, with casing in -- the canonical casing for the source file where it is defined. -- renameref provides information on renaming. If the entity is -- a package, object or overloadable entity which is declared by -- a renaming declaration, and the renaming refers to an entity -- with a simple identifier or expanded name, then renameref has -- the form: -- =line:col -- Here line:col give the reference to the identifier that appears -- in the renaming declaration. Note that we never need a file entry, -- since this identifier is always in the current file in which the -- entity is declared. Currently, renameref appears only for the -- simple renaming case. If the renaming reference is a complex -- expressions, then renameref is omitted. Here line/col give -- line/column as defined above. -- instref is only present for package and subprogram instances. The -- information in instref is the location of the point of declaration -- of the generic parent unit. This part has the form: -- [file|line] -- without column information, on the reasonable assumption that -- there is only one unit per line (the same assumption is made in -- references to entities declared within instances, see below). -- typeref is the reference for a related type. This part is -- optional. It is present for the following cases: -- derived types (points to the parent type) LR=<> -- access types (points to designated type) LR=() -- array types (points to component type) LR=() -- subtypes (points to ancestor type) LR={} -- functions (points to result type) LR={} -- enumeration literals (points to enum type) LR={} -- objects and components (points to type) LR={} -- For a type that implements multiple interfaces, there is an -- entry of the form LR=<> for each of the interfaces appearing -- in the type declaration. In the data structures of ali.ads, -- the type that the entity extends (or the first interface if -- there is no such type) is stored in Xref_Entity_Record.Tref*, -- additional interfaces are stored in the list of references -- with a special type of Interface_Reference. -- For an array type, there is an entry of the form LR=<> for each -- of the index types appearing in the type declaration. The index -- types follow the entry for the component type. In the data -- structures of ali.ads, however, the list of index types are -- output in the list of references with a special Rtype set to -- Array_Index_Reference. -- In the above list LR shows the brackets used in the output which -- has one of the two following forms: -- L file | line type col R user entity -- L name-in-lower-case R standard entity -- For the form for a user entity, file is the dependency number -- of the file containing the declaration of the related type. -- This number and the following vertical bar are omitted if the -- relevant type is defined in the same file as the current entity. -- The line, type, col are defined as previously described, and -- specify the location of the relevant type declaration in the -- referenced file. For the standard entity form, the name between -- the brackets is the normal name of the entity in lower case. -- overref is present for overriding operations (procedures and -- functions), and provides information on the operation that it -- overrides. This information has the format: -- '<' file | line 'o' col '>' -- file is the dependency number of the file containing the -- declaration of the overridden operation. It and the following -- vertical bar are omitted if the file is the same as that of -- the overriding operation. -- There may be zero or more ref entries on each line -- file | line type col [...] -- file is the dependency number of the file with the reference. -- It and the following vertical bar are omitted if the file is -- the same as the previous ref, and the refs for the current -- file are first (and do not need a bar). -- line is the line number of the reference -- col is the column number of the reference, as defined above -- type is one of -- b = body entity -- c = completion of private or incomplete type -- d = discriminant of type -- D = object definition -- e = end of spec -- E = first private entity -- H = abstract type -- i = implicit reference -- k = implicit reference to parent unit in child unit -- l = label on END line -- m = modification -- o = own variable reference (SPARK only) -- p = primitive operation -- P = overriding primitive operation -- r = reference -- R = subprogram reference in dispatching call -- s = subprogram reference in a static call -- t = end of body -- w = WITH line -- x = type extension -- z = generic formal parameter -- > = subprogram IN parameter -- = = subprogram IN OUT parameter -- < = subprogram OUT parameter -- ^ = subprogram ACCESS parameter -- b is used for spec entities that are repeated in a body, -- including the unit (subprogram, package, task, protected body, -- protected entry) name itself, and in the case of a subprogram, -- the formals. This letter is also used for the occurrence of -- entry names in accept statements. Such entities are not -- considered to be definitions for cross-referencing purposes, -- but rather are considered to be references to the corresponding -- spec entities, marked with this special type. -- c is similar to b but is used to mark the completion of a -- private or incomplete type. As with b, the completion is not -- regarded as a separate definition, but rather a reference to -- the initial declaration, marked with this special type. -- d is used to identify a discriminant of a type. If this is -- an incomplete or private type with discriminants, the entry -- denotes the occurrence of the discriminant in the partial view -- which is also the point of definition of the discriminant. The -- occurrence of the same discriminant in the full view is a -- regular reference to it. -- e is used to identify the end of a construct in the following -- cases: -- Block Statement end [block_IDENTIFIER]; -- Loop Statement end loop [loop_IDENTIFIER]; -- Package Specification end [[PARENT_UNIT_NAME .] IDENTIFIER]; -- Task Definition end [task_IDENTIFIER]; -- Protected Definition end [protected_IDENTIFIER]; -- Record Definition end record; -- Enumeration Definition ); -- Note that 'e' entries are special in that they appear even -- in referencing units (normally xref entries appear only for -- references in the extended main source unit (see Lib) to which -- the ali applies. But 'e' entries are really structural and -- simply indicate where packages end. This information can be -- used to reconstruct scope information for any entities -- referenced from within the package. The line/column values -- for these entries point to the semicolon ending the construct. -- i is used to identify a reference to the entity in a generic -- actual or in a default in a call. The node that denotes the -- entity does not come from source, but it has the Sloc of the -- source node that generates the implicit reference, and it is -- useful to record this one. -- k is another non-standard reference type, used to record a -- reference from a child unit to its parent. For various cross- -- referencing tools, we need a pointer from the xref entries for -- the child to the parent. This is the opposite way round from -- normal xref entries, since the reference is *from* the child -- unit *to* the parent unit, yet appears in the xref entries for -- the child. Consider this example: -- -- package q is -- end; -- package q.r is -- end q.r; -- -- The ali file for q-r.ads has these entries -- -- D q.ads -- D q-r.ads -- D system.ads -- X 1 q.ads -- 1K9*q 2e4 2|1r9 2r5 -- X 2 q-r.ads -- 1K11*r 1|1k9 2|2l7 2e8 -- -- Here the 2|1r9 entry appearing in the section for the parent -- is the normal reference from the child to the parent. The 1k9 -- entry in the section for the child duplicates this information -- but appears in the child rather than the parent. -- l is used to identify the occurrence in the source of the name -- on an end line. This is just a syntactic reference which can be -- ignored for semantic purposes (e.g. a call graph construction). -- Again, in the case of an accept there can be multiple l lines. -- o is used for variables referenced from a SPARK 'own' -- definition. In the SPARK language, it is allowed to use a -- variable before its actual declaration. -- p is used to mark a primitive operation of the given entity. -- For example, if we have a type Tx, and a primitive operation -- Pq of this type, then an entry in the list of references to -- Tx will point to the declaration of Pq. Note that this entry -- type is unusual because it an implicit rather than explicit, -- and the name of the reference does not match the name of the -- entity for which a reference is generated. These entries are -- generated only for entities declared in the extended main -- source unit (main unit itself, its separate spec (if any). -- and all subunits (considered recursively). -- If the primitive operation overrides an inherited primitive -- operation of the parent type, the letter 'P' is used in the -- corresponding entry. -- R is used to mark a dispatching call. The reference is to -- the specification of the primitive operation of the root -- type when the call has a controlling argument in its class. -- s is used to mark a static subprogram call. The reference is -- to the specification of the subprogram being called. -- t is similar to e. It identifies the end of a corresponding -- body (such a reference always links up with a b reference) -- Subprogram Body end [DESIGNATOR]; -- Package Body end [[PARENT_UNIT_NAME .] IDENTIFIER]; -- Task Body end [task_IDENTIFIER]; -- Entry Body end [entry_IDENTIFIER]; -- Protected Body end [protected_IDENTIFIER] -- Accept Statement end [entry_IDENTIFIER]]; -- Note that in the case of accept statements, there can -- be multiple b and t entries for the same entity. -- x is used to identify the reference as the entity from which a -- tagged type is extended. This allows immediate access to the -- parent of a tagged type. -- z is used on the cross-reference line for a generic unit, -- to mark the definition of a generic formal of the unit. This -- entry type is similar to 'k' and 'p' in that it is an implicit -- reference for an entity with a different name. -- The characters >, <. =, and ^ are used on the cross-reference -- line for a subprogram, to denote formal parameters and their -- modes. As with the 'z' and 'p' entries, each such entry is -- an implicit reference to an entity with a different name. -- [..] is used for generic instantiation references. These -- references are present only if the entity in question is -- a generic entity, and in that case the [..] contains the -- reference for the instantiation. In the case of nested -- instantiations, this can be nested [...[...[...]]] etc. The -- reference is of the form [file|line] no column is present since -- it is assumed that only one instantiation appears on a single -- source line. Note that the appearance of file numbers in such -- references follows the normal rules (present only if needed, -- and resets the current file for subsequent references). -- Examples: -- 44B5*Flag_Type{boolean} 5r23 6m45 3|9r35 11r56 -- This line gives references for the publicly visible Boolean -- type Flag_Type declared on line 44, column 5. There are four -- references -- a reference on line 5, column 23 of the current file -- a modification on line 6, column 45 of the current file -- a reference on line 9, column 35 of unit number 3 -- a reference on line 11, column 56 of unit number 3 -- 2U13 p3=2:35 5b13 8r4 12r13 12t15 -- This line gives references for the non-publicly visible -- procedure p3 declared on line 2, column 13. This procedure -- renames the procedure whose identifier reference is at -- line 2 column 35. There are four references: -- the corresponding body entity at line 5, column 13, -- of the current file. -- a reference (e.g. a call) at line 8 column 4 of the -- current file. -- the END line of the body has an explicit reference to -- the name of the procedure at line 12, column 13. -- the body ends at line 12, column 15, just past this label -- 16I9*My_Type<2|4I9> 18r8 -- This line gives references for the publicly visible Integer -- derived type My_Type declared on line 16, column 9. It also -- gives references to the parent type declared in the unit -- number 2 on line 4, column 9. There is one reference: -- a reference (e.g. a variable declaration) at line 18 column -- 4 of the current file. -- 10I3*Genv{integer} 3|4I10[6|12] -- This line gives a reference for the entity Genv in a generic -- package. The reference in file 3, line 4, col 10, refers to an -- instance of the generic where the instantiation can be found in -- file 6 at line 12. -- Continuation lines are used if the reference list gets too long, -- a continuation line starts with a period, and then has references -- continuing from the previous line. The references are sorted first -- by unit, then by position in the source. -- Note on handling of generic entities. The cross-reference is oriented -- towards source references, so the entities in a generic instantiation -- are not considered distinct from the entities in the template. All -- definitions and references from generic instantiations are suppressed, -- since they will be generated from the template. Any references to -- entities in a generic instantiation from outside the instantiation -- are considered to be references to the original template entity. ---------------------------------------- -- Cross-Reference Entity Identifiers -- ---------------------------------------- -- In the cross-reference section of the ali file, entity types are -- identified by a single letter, indicating the entity type. The following -- table indicates the letter. A space for an entry is used for entities -- that do not appear in the cross-reference table. -- For objects, the character * appears in this table. In the xref listing, -- this character is replaced by the lower case letter that corresponds to -- the type of the object. For example, if a variable is of a Float type, -- then, since the type is represented by an upper case F, the object would -- be represented by a lower case f. -- A special exception is the case of booleans, whose entities are normal -- E_Enumeration_Type or E_Enumeration_Subtype entities, but which appear -- as B/b in the xref lines, rather than E/e. -- For private types, the character + appears in the table. In this case -- the kind of the underlying type is used, if available, to determine the -- character to use in the xref listing. The listing will still include a -- '+' for a generic private type, for example, but will retain the '*' for -- an object or formal parameter of such a type. -- For subprograms, the characters 'U' and 'V' appear in the table, -- indicating procedures and functions. If the operation is abstract, -- these letters are replaced in the xref by 'x' and 'y' respectively. Xref_Entity_Letters : constant array (Entity_Kind) of Character := (E_Abstract_State => '@', E_Access_Attribute_Type => 'P', E_Access_Protected_Subprogram_Type => 'P', E_Access_Subprogram_Type => 'P', E_Access_Subtype => 'P', E_Access_Type => 'P', E_Allocator_Type => ' ', E_Anonymous_Access_Protected_Subprogram_Type => ' ', E_Anonymous_Access_Subprogram_Type => ' ', E_Anonymous_Access_Type => ' ', E_Array_Subtype => 'A', E_Array_Type => 'A', E_Block => 'q', E_Class_Wide_Subtype => 'C', E_Class_Wide_Type => 'C', E_Component => '*', E_Constant => '*', E_Decimal_Fixed_Point_Subtype => 'D', E_Decimal_Fixed_Point_Type => 'D', E_Discriminant => '*', E_Entry => 'Y', E_Entry_Family => 'Y', E_Entry_Index_Parameter => '*', E_Enumeration_Literal => 'n', E_Enumeration_Subtype => 'E', -- B for boolean E_Enumeration_Type => 'E', -- B for boolean E_Exception => 'X', E_Exception_Type => ' ', E_Floating_Point_Subtype => 'F', E_Floating_Point_Type => 'F', E_Function => 'V', E_General_Access_Type => 'P', E_Generic_Function => 'v', E_Generic_In_Out_Parameter => '*', E_Generic_In_Parameter => '*', E_Generic_Package => 'k', E_Generic_Procedure => 'u', E_Label => 'L', E_Limited_Private_Subtype => '+', E_Limited_Private_Type => '+', E_Loop => 'l', E_Loop_Parameter => '*', E_In_Out_Parameter => '*', E_In_Parameter => '*', E_Incomplete_Subtype => '+', E_Incomplete_Type => '+', E_Modular_Integer_Subtype => 'M', E_Modular_Integer_Type => 'M', E_Named_Integer => 'N', E_Named_Real => 'N', E_Operator => 'V', E_Ordinary_Fixed_Point_Subtype => 'O', E_Ordinary_Fixed_Point_Type => 'O', E_Out_Parameter => '*', E_Package => 'K', E_Private_Subtype => '+', E_Private_Type => '+', E_Procedure => 'U', E_Protected_Subtype => 'W', E_Protected_Type => 'W', E_Record_Subtype => 'R', E_Record_Subtype_With_Private => 'R', E_Record_Type => 'R', E_Record_Type_With_Private => 'R', E_Return_Statement => ' ', E_Signed_Integer_Subtype => 'I', E_Signed_Integer_Type => 'I', E_String_Literal_Subtype => ' ', E_Subprogram_Type => ' ', E_Task_Subtype => 'T', E_Task_Type => 'T', E_Variable => '*', E_Void => ' ', -- The following entities are not ones to which we gather the cross- -- references, since it does not make sense to do so (e.g. references -- to a package are to the spec, not the body). Indeed the occurrence of -- the body entity is considered to be a reference to the spec entity. E_Package_Body => ' ', E_Protected_Body => ' ', E_Subprogram_Body => ' ', E_Task_Body => ' '); -- The following table is for information purposes. It shows the use of -- each character appearing as an entity type. -- letter lower case usage UPPER CASE USAGE -- a array object (except string) array type (except string) -- b Boolean object Boolean type -- c class-wide object class-wide type -- d decimal fixed-point object decimal fixed-point type -- e non-Boolean enumeration object non_Boolean enumeration type -- f floating-point object floating-point type -- g C/C++ macro C/C++ fun-like macro -- h Interface (Ada 2005) Abstract type -- i signed integer object signed integer type -- j C++ class object C++ class -- k generic package package -- l label on loop label on statement -- m modular integer object modular integer type -- n enumeration literal named number -- o ordinary fixed-point object ordinary fixed-point type -- p access object access type -- q label on block C/C++ include file -- r record object record type -- s string object string type -- t task object task type -- u generic procedure procedure -- v generic function or operator function or operator -- w protected object protected type -- x abstract procedure exception -- y abstract function entry or entry family -- z generic formal parameter (unused) --------------------------------------------------- -- Handling of Imported and Exported Subprograms -- --------------------------------------------------- -- If a pragma Import or Interface applies to a subprogram, the pragma is -- the completion of the subprogram. This is noted in the ALI file by -- making the occurrence of the subprogram in the pragma into a body -- reference ('b') and by including the external name of the subprogram and -- its language, bracketed by '<' and '>' in that reference. For example: -- 3U13*imported_proc 4b21 -- indicates that procedure imported_proc, declared at line 3, has a pragma -- Import at line 4, that its body is in C, and that the link name as given -- in the pragma is "there". -- If a pragma Export applies to a subprogram exported to a foreign -- language (ie. the pragma has convention different from Ada), then the -- pragma is annotated in the ALI file by making the occurrence of the -- subprogram in the pragma into an implicit reference ('i') and by -- including the external name of the subprogram and its language, -- bracketed by '<' and '>' in that reference. For example: -- 3U13*exported_proc 4i21 -- indicates that procedure exported_proc, declared at line 3, has a pragma -- Export at line 4, that its body is exported to C, and that the link name -- as given in the pragma is "here". ----------------------------- -- SPARK Xrefs Information -- ----------------------------- -- This package defines procedures for collecting SPARK cross-reference -- information and printing in ALI files. package SPARK_Specific is function Enclosing_Subprogram_Or_Library_Package (N : Node_Id) return Entity_Id; -- Return the closest enclosing subprogram or library-level package. -- This ensures that GNATprove can distinguish local variables from -- global variables. -- -- ??? This routine should only be used for processing related to -- cross-references, where it might return wrong result but must avoid -- crashes on ill-formed source code. It is wrong to use it where exact -- result is needed. procedure Generate_Dereference (N : Node_Id; Typ : Character := 'r'); -- This procedure is called to record a dereference. N is the location -- of the dereference. generic with procedure Process (Index : Int; Xref : SPARK_Xrefs.SPARK_Xref_Record); procedure Iterate_SPARK_Xrefs; -- Call Process on cross-references relevant to the SPARK backend with -- parameter Xref holding the relevant subset of the xref entry and -- Index holding the position in the original tables with references -- (if positive) or dereferences (if negative). end SPARK_Specific; ----------------- -- Subprograms -- ----------------- procedure Generate_Definition (E : Entity_Id); -- Records the definition of an entity procedure Generate_Operator_Reference (N : Node_Id; T : Entity_Id); -- Node N is an operator node, whose entity has been set. If this entity -- is a user defined operator (i.e. an operator not defined in package -- Standard), then a reference to the operator is recorded at node N. -- T is the operand type of the operator. A reference to the operator is an -- implicit reference to the type, and that needs to be recorded to avoid -- spurious warnings on unused entities, when the operator is a renaming of -- a predefined operator. procedure Generate_Reference (E : Entity_Id; N : Node_Id; Typ : Character := 'r'; Set_Ref : Boolean := True; Force : Boolean := False); -- This procedure is called to record a reference. N is the location of the -- reference and E is the referenced entity. Typ is one of: -- -- a character already described in the description of ref entries above -- ' ' for dummy reference (see below) -- -- Note: all references to incomplete or private types are to the original -- (incomplete or private type) declaration. The full declaration is -- treated as a reference with type 'c'. -- -- Note: all references to packages or subprograms are to the entity for -- the spec. The entity in the body is treated as a reference with type -- 'b'. Similar handling for references to subprogram formals. -- -- The call has no effect if N is not in the extended main source unit. -- This check is omitted for type 'e' references (where it is useful to -- have structural scoping information for other than the main source), -- and for 'p' (since we want to pick up inherited primitive operations -- that are defined in other packages). -- -- The call also has no effect if any of the following conditions hold: -- -- cross-reference collection is disabled -- entity does not come from source (and Force is False) -- reference does not come from source (and Force is False) -- the entity is not one for which xrefs are appropriate -- the type letter is blank -- the node N is not an identifier, defining identifier, or expanded name -- the type is 'p' and the entity is not in the extended main source -- -- If all these conditions are met, then the Is_Referenced flag of E is set -- (unless Set_Ref is False) and a cross-reference entry is recorded for -- later output when Output_References is called. -- -- Note: the dummy space entry is for the convenience of some callers, -- who find it easier to pass a space to suppress the entry than to do -- a specific test. The call has no effect if the type is a space. -- -- The parameter Set_Ref is normally True, and indicates that in addition -- to generating a cross-reference, the Referenced flag of the specified -- entity should be set. If this parameter is False, then setting of the -- Referenced flag is inhibited. -- -- The parameter Force is set to True to force a reference to be generated -- even if Comes_From_Source is false. This is used for certain implicit -- references, and also for end label references. procedure Generate_Reference_To_Formals (E : Entity_Id); -- Add a reference to the definition of each formal on the line for -- a subprogram or an access_to_subprogram type. procedure Generate_Reference_To_Generic_Formals (E : Entity_Id); -- Add a reference to the definition of each generic formal on the line -- for a generic unit. procedure Output_References; -- Output references to the current ali file procedure Initialize; -- Initialize internal tables end Lib.Xref;