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NAME
xref - A Cross Reference Tool for analyzing dependencies between functions, modules,
applications and releases.
DESCRIPTION
Xref is a cross reference tool that can be used for finding dependencies between
functions, modules, applications and releases.
Calls between functions are either local calls like f(), or external calls like m:f().
Module data, which are extracted from BEAM files, include local functions, exported
functions, local calls and external calls. By default, calls to built-in functions () are
ignored, but if the option builtins, accepted by some of this module's functions, is set
to true, calls to BIFs are included as well. It is the analyzing OTP version that decides
what functions are BIFs. Functional objects are assumed to be called where they are
created (and nowhere else). Unresolved calls are calls to apply or spawn with variable
module, variable function, or variable arguments. Examples are M:F(a), apply(M, f, [a]),
and spawn(m, f(), Args). Unresolved calls are represented by calls where variable modules
have been replaced with the atom '$M_EXPR', variable functions have been replaced with the
atom '$F_EXPR', and variable number of arguments have been replaced with the number -1.
The above mentioned examples are represented by calls to '$M_EXPR':'$F_EXPR'/1,
'$M_EXPR':f/1, and m:'$F_EXPR'/-1. The unresolved calls are a subset of the external
calls.
Warning:
Unresolved calls make module data incomplete, which implies that the results of analyses
may be invalid.
Applications are collections of modules. The modules' BEAM files are located in the ebin
subdirectory of the application directory. The name of the application directory
determines the name and version of the application. Releases are collections of
applications located in the lib subdirectory of the release directory. There is more to
read about applications and releases in the Design Principles book.
Xref servers are identified by names, supplied when creating new servers. Each Xref server
holds a set of releases, a set of applications, and a set of modules with module data.
Xref servers are independent of each other, and all analyses are evaluated in the context
of one single Xref server (exceptions are the functions m/1 and d/1 which do not use
servers at all). The mode of an Xref server determines what module data are extracted from
BEAM files as modules are added to the server. Starting with R7, BEAM files compiled with
the option debug_info contain so called debug information, which is an abstract
representation of the code. In functions mode, which is the default mode, function calls
and line numbers are extracted from debug information. In modules mode, debug information
is ignored if present, but dependencies between modules are extracted from other parts of
the BEAM files. The modules mode is significantly less time and space consuming than the
functions mode, but the analyses that can be done are limited.
An analyzed module is a module that has been added to an Xref server together with its
module data. A library module is a module located in some directory mentioned in the
library path. A library module is said to be used if some of its exported functions are
used by some analyzed module. An unknown module is a module that is neither an analyzed
module nor a library module, but whose exported functions are used by some analyzed
module. An unknown function is a used function that is neither local or exported by any
analyzed module nor exported by any library module. An undefined function is an externally
used function that is not exported by any analyzed module or library module. With this
notion, a local function can be an undefined function, namely if it is externally used
from some module. All unknown functions are also undefined functions; there is a figure in
the User's Guide that illustrates this relationship.
Starting with R9C, the module attribute tag deprecated can be used to inform Xref about
deprecated functions and optionally when functions are planned to be removed. A few
examples show the idea:
-deprecated({f,1}).:
The exported function f/1 is deprecated. Nothing is said whether f/1 will be removed
or not.
-deprecated({f,'_'}).:
All exported functions f/0, f/1 and so on are deprecated.
-deprecated(module).:
All exported functions in the module are deprecated. Equivalent to
-deprecated({'_','_'})..
-deprecated([{g,1,next_version}]).:
The function g/1 is deprecated and will be removed in next version.
-deprecated([{g,2,next_major_release}]).:
The function g/2 is deprecated and will be removed in next major release.
-deprecated([{g,3,eventually}]).:
The function g/3 is deprecated and will eventually be removed.
-deprecated({'_','_',eventually}).:
All exported functions in the module are deprecated and will eventually be removed.
Before any analysis can take place, module data must be set up. For instance, the cross
reference and the unknown functions are computed when all module data are known. The
functions that need complete data (analyze, q, variables) take care of setting up data
automatically. Module data need to be set up (again) after calls to any of the add,
replace, remove, set_library_path or update functions.
The result of setting up module data is the Call Graph. A (directed) graph consists of a
set of vertices and a set of (directed) edges. The edges represent calls (From, To)
between functions, modules, applications or releases. From is said to call To, and To is
said to be used by From. The vertices of the Call Graph are the functions of all module
data: local and exported functions of analyzed modules; used BIFs; used exported functions
of library modules; and unknown functions. The functions module_info/0,1 added by the
compiler are included among the exported functions, but only when called from some module.
The edges are the function calls of all module data. A consequence of the edges being a
set is that there is only one edge if a function is locally or externally used several
times on one and the same line of code.
The Call Graph is represented by Erlang terms (the sets are lists), which is suitable for
many analyses. But for analyses that look at chains of calls, a list representation is
much too slow. Instead the representation offered by the digraph module is used. The
translation of the list representation of the Call Graph - or a subgraph thereof - to the
digraph representation does not come for free, so the language used for expressing queries
to be described below has a special operator for this task and a possibility to save the
digraph representation for subsequent analyses.
In addition to the Call Graph there is a graph called the Inter Call Graph. This is a
graph of calls (From, To) such that there is a chain of calls from From to To in the Call
Graph, and every From and To is an exported function or an unused local function. The
vertices are the same as for the Call Graph.
Calls between modules, applications and releases are also directed graphs. The types of
the vertices and edges of these graphs are (ranging from the most special to the most
general): Fun for functions; Mod for modules; App for applications; and Rel for releases.
The following paragraphs will describe the different constructs of the language used for
selecting and analyzing parts of the graphs, beginning with the constants:
* Expression ::= Constants
* Constants ::= Consts | Consts : Type | RegExpr
* Consts ::= Constant | [Constant, ...] | {Constant, ...}
* Constant ::= Call | Const
* Call ::= FunSpec -> FunSpec | {MFA, MFA} | AtomConst -> AtomConst | {AtomConst,
AtomConst}
* Const ::= AtomConst | FunSpec | MFA
* AtomConst ::= Application | Module | Release
* FunSpec ::= Module : Function / Arity
* MFA ::= {Module, Function, Arity}
* RegExpr ::= RegString : Type | RegFunc | RegFunc : Type
* RegFunc ::= RegModule : RegFunction / RegArity
* RegModule ::= RegAtom
* RegFunction ::= RegAtom
* RegArity ::= RegString | Number | _ | -1
* RegAtom ::= RegString | Atom | _
* RegString ::= - a regular expression, as described in the re module, enclosed in
double quotes -
* Type ::= Fun | Mod | App | Rel
* Function ::= Atom
* Application ::= Atom
* Module ::= Atom
* Release ::= Atom
* Arity ::= Number | -1
* Atom ::= - same as Erlang atoms -
* Number ::= - same as non-negative Erlang integers -
Examples of constants are: kernel, kernel->stdlib, [kernel, sasl], [pg -> mnesia, {tv,
mnesia}] : Mod. It is an error if an instance of Const does not match any vertex of any
graph. If there are more than one vertex matching an untyped instance of AtomConst, then
the one of the most general type is chosen. A list of constants is interpreted as a set of
constants, all of the same type. A tuple of constants constitute a chain of calls (which
may, but does not have to, correspond to an actual chain of calls of some graph).
Assigning a type to a list or tuple of Constant is equivalent to assigning the type to
each Constant.
Regular expressions are used as a means to select some of the vertices of a graph. A
RegExpr consisting of a RegString and a type - an example is "xref_.*" : Mod - is
interpreted as those modules (or applications or releases, depending on the type) that
match the expression. Similarly, a RegFunc is interpreted as those vertices of the Call
Graph that match the expression. An example is "xref_.*":"add_.*"/"(2|3)", which matches
all add functions of arity two or three of any of the xref modules. Another example, one
that matches all functions of arity 10 or more: _:_/"[1-9].+". Here _ is an abbreviation
for ".*", that is, the regular expression that matches anything.
The syntax of variables is simple:
* Expression ::= Variable
* Variable ::= - same as Erlang variables -
There are two kinds of variables: predefined variables and user variables. Predefined
variables hold set up module data, and cannot be assigned to but only used in queries.
User variables on the other hand can be assigned to, and are typically used for temporary
results while evaluating a query, and for keeping results of queries for use in subsequent
queries. The predefined variables are (variables marked with (*) are available in
functions mode only):
E:
Call Graph Edges (*).
V:
Call Graph Vertices (*).
M:
Modules. All modules: analyzed modules, used library modules, and unknown modules.
A:
Applications.
R:
Releases.
ME:
Module Edges. All module calls.
AE:
Application Edges. All application calls.
RE:
Release Edges. All release calls.
L:
Local Functions (*). All local functions of analyzed modules.
X:
Exported Functions. All exported functions of analyzed modules and all used exported
functions of library modules.
F:
Functions (*).
B:
Used BIFs. B is empty if builtins is false for all analyzed modules.
U:
Unknown Functions.
UU:
Unused Functions (*). All local and exported functions of analyzed modules that have
not been used.
XU:
Externally Used Functions. Functions of all modules - including local functions - that
have been used in some external call.
LU:
Locally Used Functions (*). Functions of all modules that have been used in some local
call.
LC:
Local Calls (*).
XC:
External Calls (*).
AM:
Analyzed Modules.
UM:
Unknown Modules.
LM:
Used Library Modules.
UC:
Unresolved Calls. Empty in modules mode.
EE:
Inter Call Graph Edges (*).
DF:
Deprecated Functions. All deprecated exported functions and all used deprecated BIFs.
DF_1:
Deprecated Functions. All deprecated functions to be removed in next version.
DF_2:
Deprecated Functions. All deprecated functions to be removed in next version or next
major release.
DF_3:
Deprecated Functions. All deprecated functions to be removed in next version, next
major release, or later.
These are a few facts about the predefined variables (the set operators + (union) and -
(difference) as well as the cast operator (Type) are described below):
* F is equal to L + X.
* V is equal to X + L + B + U, where X, L, B and U are pairwise disjoint (that is, have
no elements in common).
* UU is equal to V - (XU + LU), where LU and XU may have elements in common. Put in
another way:
* V is equal to UU + XU + LU.
* E is equal to LC + XC. Note that LC and XC may have elements in common, namely if some
function is locally and externally used from one and the same function.
* U is a subset of XU.
* B is a subset of XU.
* LU is equal to range LC.
* XU is equal to range XC.
* LU is a subset of F.
* UU is a subset of F.
* range UC is a subset of U.
* M is equal to AM + LM + UM, where AM, LM and UM are pairwise disjoint.
* ME is equal to (Mod) E.
* AE is equal to (App) E.
* RE is equal to (Rel) E.
* (Mod) V is a subset of M. Equality holds if all analyzed modules have some local,
exported, or unknown function.
* (App) M is a subset of A. Equality holds if all applications have some module.
* (Rel) A is a subset of R. Equality holds if all releases have some application.
* DF_1 is a subset of DF_2.
* DF_2 is a subset of DF_3.
* DF_3 is a subset of DF.
* DF is a subset of X + B.
An important notion is that of conversion of expressions. The syntax of a cast expression
is:
* Expression ::= ( Type ) Expression
The interpretation of the cast operator depends on the named type Type, the type of
Expression, and the structure of the elements of the interpretation of Expression. If the
named type is equal to the expression type, no conversion is done. Otherwise, the
conversion is done one step at a time; (Fun) (App) RE, for instance, is equivalent to
(Fun) (Mod) (App) RE. Now assume that the interpretation of Expression is a set of
constants (functions, modules, applications or releases). If the named type is more
general than the expression type, say Mod and Fun respectively, then the interpretation of
the cast expression is the set of modules that have at least one of their functions
mentioned in the interpretation of the expression. If the named type is more special than
the expression type, say Fun and Mod, then the interpretation is the set of all the
functions of the modules (in modules mode, the conversion is partial since the local
functions are not known). The conversions to and from applications and releases work
analogously. For instance, (App) "xref_.*" : Mod returns all applications containing at
least one module such that xref_ is a prefix of the module name.
Now assume that the interpretation of Expression is a set of calls. If the named type is
more general than the expression type, say Mod and Fun respectively, then the
interpretation of the cast expression is the set of calls (M1, M2) such that the
interpretation of the expression contains a call from some function of M1 to some function
of M2. If the named type is more special than the expression type, say Fun and Mod, then
the interpretation is the set of all function calls (F1, F2) such that the interpretation
of the expression contains a call (M1, M2) and F1 is a function of M1 and F2 is a function
of M2 (in modules mode, there are no functions calls, so a cast to Fun always yields an
empty set). Again, the conversions to and from applications and releases work analogously.
The interpretation of constants and variables are sets, and those sets can be used as the
basis for forming new sets by the application of set operators. The syntax:
* Expression ::= Expression BinarySetOp Expression
* BinarySetOp ::= + | * | -
+, * and - are interpreted as union, intersection and difference respectively: the union
of two sets contains the elements of both sets; the intersection of two sets contains the
elements common to both sets; and the difference of two sets contains the elements of the
first set that are not members of the second set. The elements of the two sets must be of
the same structure; for instance, a function call cannot be combined with a function. But
if a cast operator can make the elements compatible, then the more general elements are
converted to the less general element type. For instance, M + F is equivalent to (Fun) M +
F, and E - AE is equivalent to E - (Fun) AE. One more example: X * xref : Mod is
interpreted as the set of functions exported by the module xref; xref : Mod is converted
to the more special type of X (Fun, that is) yielding all functions of xref, and the
intersection with X (all functions exported by analyzed modules and library modules) is
interpreted as those functions that are exported by some module and functions of xref.
There are also unary set operators:
* Expression ::= UnarySetOp Expression
* UnarySetOp ::= domain | range | strict
Recall that a call is a pair (From, To). domain applied to a set of calls is interpreted
as the set of all vertices From, and range as the set of all vertices To. The
interpretation of the strict operator is the operand with all calls on the form (A, A)
removed.
The interpretation of the restriction operators is a subset of the first operand, a set of
calls. The second operand, a set of vertices, is converted to the type of the first
operand. The syntax of the restriction operators:
* Expression ::= Expression RestrOp Expression
* RestrOp ::= |
* RestrOp ::= ||
* RestrOp ::= |||
The interpretation in some detail for the three operators:
|:
The subset of calls from any of the vertices.
||:
The subset of calls to any of the vertices.
|||:
The subset of calls to and from any of the vertices. For all sets of calls CS and all
sets of vertices VS, CS ||| VS is equivalent to CS | VS * CS || VS.
Two functions (modules, applications, releases) belong to the same strongly connected
component if they call each other (in)directly. The interpretation of the components
operator is the set of strongly connected components of a set of calls. The condensation
of a set of calls is a new set of calls between the strongly connected components such
that there is an edge between two components if there is some constant of the first
component that calls some constant of the second component.
The interpretation of the of operator is a chain of calls of the second operand (a set of
calls) that passes throw all of the vertices of the first operand (a tuple of constants),
in the given order. The second operand is converted to the type of the first operand. For
instance, the of operator can be used for finding out whether a function calls another
function indirectly, and the chain of calls demonstrates how. The syntax of the graph
analyzing operators:
* Expression ::= Expression GraphOp Expression
* GraphOp ::= components | condensation | of
As was mentioned before, the graph analyses operate on the digraph representation of
graphs. By default, the digraph representation is created when needed (and deleted when no
longer used), but it can also be created explicitly by use of the closure operator:
* Expression ::= ClosureOp Expression
* ClosureOp ::= closure
The interpretation of the closure operator is the transitive closure of the operand.
The restriction operators are defined for closures as well; closure E | xref : Mod is
interpreted as the direct or indirect function calls from the xref module, while the
interpretation of E | xref : Mod is the set of direct calls from xref. If some graph is to
be used in several graph analyses, it saves time to assign the digraph representation of
the graph to a user variable, and then make sure that every graph analysis operates on
that variable instead of the list representation of the graph.
The lines where functions are defined (more precisely: where the first clause begins) and
the lines where functions are used are available in functions mode. The line numbers refer
to the files where the functions are defined. This holds also for files included with the
-include and -include_lib directives, which may result in functions defined apparently in
the same line. The line operators are used for assigning line numbers to functions and for
assigning sets of line numbers to function calls. The syntax is similar to the one of the
cast operator:
* Expression ::= ( LineOp) Expression
* Expression ::= ( XLineOp) Expression
* LineOp ::= Lin | ELin | LLin | XLin
* XLineOp ::= XXL
The interpretation of the Lin operator applied to a set of functions assigns to each
function the line number where the function is defined. Unknown functions and functions of
library modules are assigned the number 0.
The interpretation of some LineOp operator applied to a set of function calls assigns to
each call the set of line numbers where the first function calls the second function. Not
all calls are assigned line numbers by all operators:
* the Lin operator is defined for Call Graph Edges;
* the LLin operator is defined for Local Calls.
* the XLin operator is defined for External Calls.
* the ELin operator is defined for Inter Call Graph Edges.
The Lin (LLin, XLin) operator assigns the lines where calls (local calls, external calls)
are made. The ELin operator assigns to each call (From, To), for which it is defined,
every line L such that there is a chain of calls from From to To beginning with a call on
line L.
The XXL operator is defined for the interpretation of any of the LineOp operators applied
to a set of function calls. The result is that of replacing the function call with a line
numbered function call, that is, each of the two functions of the call is replaced by a
pair of the function and the line where the function is defined. The effect of the XXL
operator can be undone by the LineOp operators. For instance, (Lin) (XXL) (Lin) E is
equivalent to (Lin) E.
The +, -, * and # operators are defined for line number expressions, provided the operands
are compatible. The LineOp operators are also defined for modules, applications, and
releases; the operand is implicitly converted to functions. Similarly, the cast operator
is defined for the interpretation of the LineOp operators.
The interpretation of the counting operator is the number of elements of a set. The
operator is undefined for closures. The +, - and * operators are interpreted as the
obvious arithmetical operators when applied to numbers. The syntax of the counting
operator:
* Expression ::= CountOp Expression
* CountOp ::= #
All binary operators are left associative; for instance, A | B || C is equivalent to (A |
B) || C. The following is a list of all operators, in increasing order of precedence:
* +, -
* *
* #
* |, ||, |||
* of
* (Type)
* closure, components, condensation, domain, range, strict
Parentheses are used for grouping, either to make an expression more readable or to
override the default precedence of operators:
* Expression ::= ( Expression )
A query is a non-empty sequence of statements. A statement is either an assignment of a
user variable or an expression. The value of an assignment is the value of the right hand
side expression. It makes no sense to put a plain expression anywhere else but last in
queries. The syntax of queries is summarized by these productions:
* Query ::= Statement, ...
* Statement ::= Assignment | Expression
* Assignment ::= Variable := Expression | Variable = Expression
A variable cannot be assigned a new value unless first removed. Variables assigned to by
the = operator are removed at the end of the query, while variables assigned to by the :=
operator can only be removed by calls to forget. There are no user variables when module
data need to be set up again; if any of the functions that make it necessary to set up
module data again is called, all user variables are forgotten.
Types
application() = atom()
arity() = int() | -1
bool() = true | false
call() = {atom(), atom()} | funcall()
constant() = mfa() | module() | application() | release()
directory() = string()
file() = string()
funcall() = {mfa(), mfa()}
function() = atom()
int() = integer() >= 0
library() = atom()
library_path() = path() | code_path
mfa() = {module(), function(), arity()}
mode() = functions | modules
module() = atom()
release() = atom()
string_position() = int() | at_end
variable() = atom()
xref() = atom() | pid()
EXPORTS
add_application(Xref, Directory [, Options]) -> {ok, application()} | Error
Types:
Directory = directory()
Error = {error, module(), Reason}
Options = [Option] | Option
Option = {builtins, bool()} | {name, application()} | {verbose, bool()} |
{warnings, bool()}
Reason = {application_clash, {application(), directory(), directory()}} |
{file_error, file(), error()} | {invalid_filename, term()} | {invalid_options,
term()} | - see also add_directory -
Xref = xref()
Adds an application, the modules of the application and module data of the modules
to an Xref server. The modules will be members of the application. The default is
to use the base name of the directory with the version removed as application name,
but this can be overridden by the name option. Returns the name of the application.
If the given directory has a subdirectory named ebin, modules (BEAM files) are
searched for in that directory, otherwise modules are searched for in the given
directory.
If the mode of the Xref server is functions, BEAM files that contain no debug
information are ignored.
add_directory(Xref, Directory [, Options]) -> {ok, Modules} | Error
Types:
Directory = directory()
Error = {error, module(), Reason}
Modules = [module()]
Options = [Option] | Option
Option = {builtins, bool()} | {recurse, bool()} | {verbose, bool()} | {warnings,
bool()}
Reason = {file_error, file(), error()} | {invalid_filename, term()} |
{invalid_options, term()} | {unrecognized_file, file()} | - error from
beam_lib:chunks/2 -
Xref = xref()
Adds the modules found in the given directory and the modules' data to an Xref
server. The default is not to examine subdirectories, but if the option recurse has
the value true, modules are searched for in subdirectories on all levels as well as
in the given directory. Returns a sorted list of the names of the added modules.
The modules added will not be members of any applications.
If the mode of the Xref server is functions, BEAM files that contain no debug
information are ignored.
add_module(Xref, File [, Options]) -> {ok, module()} | Error
Types:
Error = {error, module(), Reason}
File = file()
Options = [Option] | Option
Option = {builtins, bool()} | {verbose, bool()} | {warnings, bool()}
Reason = {file_error, file(), error()} | {invalid_filename, term()} |
{invalid_options, term()} | {module_clash, {module(), file(), file()}} |
{no_debug_info, file()} | - error from beam_lib:chunks/2 -
Xref = xref()
Adds a module and its module data to an Xref server. The module will not be member
of any application. Returns the name of the module.
If the mode of the Xref server is functions, and the BEAM file contains no debug
information, the error message no_debug_info is returned.
add_release(Xref, Directory [, Options]) -> {ok, release()} | Error
Types:
Directory = directory()
Error = {error, module(), Reason}
Options = [Option] | Option
Option = {builtins, bool()} | {name, release()} | {verbose, bool()} | {warnings,
bool()}
Reason = {application_clash, {application(), directory(), directory()}} |
{file_error, file(), error()} | {invalid_filename, term()} | {invalid_options,
term()} | {release_clash, {release(), directory(), directory()}} | - see also
add_directory -
Xref = xref()
Adds a release, the applications of the release, the modules of the applications,
and module data of the modules to an Xref server. The applications will be members
of the release, and the modules will be members of the applications. The default is
to use the base name of the directory as release name, but this can be overridden
by the name option. Returns the name of the release.
If the given directory has a subdirectory named lib, the directories in that
directory are assumed to be application directories, otherwise all subdirectories
of the given directory are assumed to be application directories. If there are
several versions of some application, the one with the highest version is chosen.
If the mode of the Xref server is functions, BEAM files that contain no debug
information are ignored.
analyze(Xref, Analysis [, Options]) -> {ok, Answer} | Error
Types:
Analysis = undefined_function_calls | undefined_functions | locals_not_used |
exports_not_used | deprecated_function_calls | {deprecated_function_calls,
DeprFlag} | deprecated_functions | {deprecated_functions, DeprFlag} | {call,
FuncSpec} | {use, FuncSpec} | {module_call, ModSpec} | {module_use, ModSpec} |
{application_call, AppSpec} | {application_use, AppSpec} | {release_call,
RelSpec} | {release_use, RelSpec}
Answer = [term()]
AppSpec = application() | [application()]
DeprFlag = next_version | next_major_release | eventually
Error = {error, module(), Reason}
FuncSpec = mfa() | [mfa()]
ModSpec = module() | [module()]
Options = [Option] | Option
Option = {verbose, bool()}
RelSpec = release() | [release()]
Reason = {invalid_options, term()} | {parse_error, string_position(), term()} |
{unavailable_analysis, term()} | {unknown_analysis, term()} | {unknown_constant,
string()} | {unknown_variable, variable()}
Xref = xref()
Evaluates a predefined analysis. Returns a sorted list without duplicates of call()
or constant(), depending on the chosen analysis. The predefined analyses, which
operate on all analyzed modules, are (analyses marked with (*) are available in
functionsmode only):
undefined_function_calls(*):
Returns a list of calls to undefined functions.
undefined_functions:
Returns a list of undefined functions.
locals_not_used(*):
Returns a list of local functions that have not been locally used.
exports_not_used:
Returns a list of exported functions that have not been externally used.
deprecated_function_calls(*):
Returns a list of external calls to deprecated functions.
{deprecated_function_calls, DeprFlag}(*):
Returns a list of external calls to deprecated functions. If DeprFlag is equal
to next_version, calls to functions to be removed in next version are returned.
If DeprFlag is equal to next_major_release, calls to functions to be removed in
next major release are returned as well as calls to functions to be removed in
next version. Finally, if DeprFlag is equal to eventually, all calls to
functions to be removed are returned, including calls to functions to be
removed in next version or next major release.
deprecated_functions:
Returns a list of externally used deprecated functions.
{deprecated_functions, DeprFlag}:
Returns a list of externally used deprecated functions. If DeprFlag is equal to
next_version, functions to be removed in next version are returned. If DeprFlag
is equal to next_major_release, functions to be removed in next major release
are returned as well as functions to be removed in next version. Finally, if
DeprFlag is equal to eventually, all functions to be removed are returned,
including functions to be removed in next version or next major release.
{call, FuncSpec}(*):
Returns a list of functions called by some of the given functions.
{use, FuncSpec}(*):
Returns a list of functions that use some of the given functions.
{module_call, ModSpec}:
Returns a list of modules called by some of the given modules.
{module_use, ModSpec}:
Returns a list of modules that use some of the given modules.
{application_call, AppSpec}:
Returns a list of applications called by some of the given applications.
{application_use, AppSpec}:
Returns a list of applications that use some of the given applications.
{release_call, RelSpec}:
Returns a list of releases called by some of the given releases.
{release_use, RelSpec}:
Returns a list of releases that use some of the given releases.
d(Directory) -> [DebugInfoResult] | [NoDebugInfoResult] | Error
Types:
Directory = directory()
DebugInfoResult = {deprecated, [funcall()]} | {undefined, [funcall()]} |
{unused, [mfa()]}
Error = {error, module(), Reason}
NoDebugInfoResult = {deprecated, [mfa()]} | {undefined, [mfa()]}
Reason = {file_error, file(), error()} | {invalid_filename, term()} |
{unrecognized_file, file()} | - error from beam_lib:chunks/2 -
The modules found in the given directory are checked for calls to deprecated
functions, calls to undefined functions, and for unused local functions. The code
path is used as library path.
If some of the found BEAM files contain debug information, then those modules are
checked and a list of tuples is returned. The first element of each tuple is one
of:
* deprecated, the second element is a sorted list of calls to deprecated
functions;
* undefined, the second element is a sorted list of calls to undefined functions;
* unused, the second element is a sorted list of unused local functions.
If no BEAM file contains debug information, then a list of tuples is returned. The
first element of each tuple is one of:
* deprecated, the second element is a sorted list of externally used deprecated
functions;
* undefined, the second element is a sorted list of undefined functions.
forget(Xref) -> ok
forget(Xref, Variables) -> ok | Error
Types:
Error = {error, module(), Reason}
Reason = {not_user_variable, term()}
Variables = [variable()] | variable()
Xref = xref()
forget/1 and forget/2 remove all or some of the user variables of an xref server.
format_error(Error) -> Chars
Types:
Error = {error, module(), term()}
Chars = [char() | Chars]
Given the error returned by any function of this module, the function format_error
returns a descriptive string of the error in English. For file errors, the function
format_error/1 in the file module is called.
get_default(Xref) -> [{Option, Value}]
get_default(Xref, Option) -> {ok, Value} | Error
Types:
Error = {error, module(), Reason}
Option = builtins | recurse | verbose | warnings
Reason = {invalid_options, term()}
Value = bool()
Xref = xref()
Returns the default values of one or more options.
get_library_path(Xref) -> {ok, LibraryPath}
Types:
LibraryPath = library_path()
Xref = xref()
Returns the library path.
info(Xref) -> [Info]
info(Xref, Category) -> [{Item, [Info]}]
info(Xref, Category, Items) -> [{Item, [Info]}]
Types:
Application = [] | [application()]
Category = modules | applications | releases | libraries
Info = {application, Application} | {builtins, bool()} | {directory,
directory()} | {library_path, library_path()} | {mode, mode()} |
{no_analyzed_modules, int()} | {no_applications, int()} | {no_calls,
{NoResolved, NoUnresolved}} | {no_function_calls, {NoLocal, NoResolvedExternal,
NoUnresolved}} | {no_functions, {NoLocal, NoExternal}} |
{no_inter_function_calls, int()} | {no_releases, int()} | {release, Release} |
{version, Version}
Item = module() | application() | release() | library()
Items = Item | [Item]
NoLocal = NoExternal = NoResolvedExternal, NoResolved = NoUnresolved = int()
Release = [] | [release()]
Version = [int()]
Xref = xref()
The info functions return information as a list of pairs {Tag, term()} in some
order about the state and the module data of an Xref server.
info/1 returns information with the following tags (tags marked with (*) are
available in functions mode only):
* library_path, the library path;
* mode, the mode;
* no_releases, number of releases;
* no_applications, total number of applications (of all releases);
* no_analyzed_modules, total number of analyzed modules;
* no_calls (*), total number of calls (in all modules), regarding instances of
one function call in different lines as separate calls;
* no_function_calls (*), total number of local calls, resolved external calls and
unresolved calls;
* no_functions (*), total number of local and exported functions;
* no_inter_function_calls (*), total number of calls of the Inter Call Graph.
info/2 and info/3 return information about all or some of the analyzed modules,
applications, releases or library modules of an Xref server. The following
information is returned for every analyzed module:
* application, an empty list if the module does not belong to any application,
otherwise a list of the application name;
* builtins, whether calls to BIFs are included in the module's data;
* directory, the directory where the module's BEAM file is located;
* no_calls (*), number of calls, regarding instances of one function call in
different lines as separate calls;
* no_function_calls (*), number of local calls, resolved external calls and
unresolved calls;
* no_functions (*), number of local and exported functions;
* no_inter_function_calls (*), number of calls of the Inter Call Graph;
The following information is returned for every application:
* directory, the directory where the modules' BEAM files are located;
* no_analyzed_modules, number of analyzed modules;
* no_calls (*), number of calls of the application's modules, regarding instances
of one function call in different lines as separate calls;
* no_function_calls (*), number of local calls, resolved external calls and
unresolved calls of the application's modules;
* no_functions (*), number of local and exported functions of the application's
modules;
* no_inter_function_calls (*), number of calls of the Inter Call Graph of the
application's modules;
* release, an empty list if the application does not belong to any release,
otherwise a list of the release name;
* version, the application's version as a list of numbers. For instance, the
directory "kernel-2.6" results in the application name kernel and the
application version [2,6]; "kernel" yields the name kernel and the version [].
The following information is returned for every release:
* directory, the release directory;
* no_analyzed_modules, number of analyzed modules;
* no_applications, number of applications;
* no_calls (*), number of calls of the release's modules, regarding instances of
one function call in different lines as separate calls;
* no_function_calls (*), number of local calls, resolved external calls and
unresolved calls of the release's modules;
* no_functions (*), number of local and exported functions of the release's
modules;
* no_inter_function_calls (*), number of calls of the Inter Call Graph of the
release's modules.
The following information is returned for every library module:
* directory, the directory where the library module's BEAM file is located.
For every number of calls, functions etc. returned by the no_ tags, there is a
query returning the same number. Listed below are examples of such queries. Some of
the queries return the sum of a two or more of the no_ tags numbers. mod (app, rel)
refers to any module (application, release).
* no_analyzed_modules
* "# AM" (info/1)
* "# (Mod) app:App" (application)
* "# (Mod) rel:Rel" (release)
* no_applications
* "# A" (info/1)
* no_calls. The sum of the number of resolved and unresolved calls:
* "# (XLin) E + # (LLin) E" (info/1)
* "T = E | mod:Mod, # (LLin) T + # (XLin) T" (module)
* "T = E | app:App, # (LLin) T + # (XLin) T" (application)
* "T = E | rel:Rel, # (LLin) T + # (XLin) T" (release)
* no_functions. Functions in library modules and the functions module_info/0,1
are not counted by info. Assuming that "Extra := _:module_info/\"(0|1)\" + LM"
has been evaluated, the sum of the number of local and exported functions are:
* "# (F - Extra)" (info/1)
* "# (F * mod:Mod - Extra)" (module)
* "# (F * app:App - Extra)" (application)
* "# (F * rel:Rel - Extra)" (release)
* no_function_calls. The sum of the number of local calls, resolved external
calls and unresolved calls:
* "# LC + # XC" (info/1)
* "# LC | mod:Mod + # XC | mod:Mod" (module)
* "# LC | app:App + # XC | app:App" (application)
* "# LC | rel:Rel + # XC | mod:Rel" (release)
* no_inter_function_calls
* "# EE" (info/1)
* "# EE | mod:Mod" (module)
* "# EE | app:App" (application)
* "# EE | rel:Rel" (release)
* no_releases
* "# R" (info/1)
m(Module) -> [DebugInfoResult] | [NoDebugInfoResult] | Error
m(File) -> [DebugInfoResult] | [NoDebugInfoResult] | Error
Types:
DebugInfoResult = {deprecated, [funcall()]} | {undefined, [funcall()]} |
{unused, [mfa()]}
Error = {error, module(), Reason}
File = file()
Module = module()
NoDebugInfoResult = {deprecated, [mfa()]} | {undefined, [mfa()]}
Reason = {file_error, file(), error()} | {interpreted, module()} |
{invalid_filename, term()} | {cover_compiled, module()} | {no_such_module,
module()} | - error from beam_lib:chunks/2 -
The given BEAM file (with or without the .beam extension) or the file found by
calling code:which(Module) is checked for calls to deprecated functions, calls to
undefined functions, and for unused local functions. The code path is used as
library path.
If the BEAM file contains debug information, then a list of tuples is returned. The
first element of each tuple is one of:
* deprecated, the second element is a sorted list of calls to deprecated
functions;
* undefined, the second element is a sorted list of calls to undefined functions;
* unused, the second element is a sorted list of unused local functions.
If the BEAM file does not contain debug information, then a list of tuples is
returned. The first element of each tuple is one of:
* deprecated, the second element is a sorted list of externally used deprecated
functions;
* undefined, the second element is a sorted list of undefined functions.
q(Xref, Query [, Options]) -> {ok, Answer} | Error
Types:
Answer = false | [constant()] | [Call] | [Component] | int() | [DefineAt] |
[CallAt] | [AllLines]
Call = call() | ComponentCall
ComponentCall = {Component, Component}
Component = [constant()]
DefineAt = {mfa(), LineNumber}
CallAt = {funcall(), LineNumbers}
AllLines = {{DefineAt, DefineAt}, LineNumbers}
Error = {error, module(), Reason}
LineNumbers = [LineNumber]
LineNumber = int()
Options = [Option] | Option
Option = {verbose, bool()}
Query = string() | atom()
Reason = {invalid_options, term()} | {parse_error, string_position(), term()} |
{type_error, string()} | {type_mismatch, string(), string()} |
{unknown_analysis, term()} | {unknown_constant, string()} | {unknown_variable,
variable()} | {variable_reassigned, string()}
Xref = xref()
Evaluates a query in the context of an Xref server, and returns the value of the
last statement. The syntax of the value depends on the expression:
* A set of calls is represented by a sorted list without duplicates of call().
* A set of constants is represented by a sorted list without duplicates of
constant().
* A set of strongly connected components is a sorted list without duplicates of
Component.
* A set of calls between strongly connected components is a sorted list without
duplicates of ComponentCall.
* A chain of calls is represented by a list of constant(). The list contains the
From vertex of every call and the To vertex of the last call.
* The of operator returns false if no chain of calls between the given constants
can be found.
* The value of the closure operator (the digraph representation) is represented
by the atom 'closure()'.
* A set of line numbered functions is represented by a sorted list without
duplicates of DefineAt.
* A set of line numbered function calls is represented by a sorted list without
duplicates of CallAt.
* A set of line numbered functions and function calls is represented by a sorted
list without duplicates of AllLines.
For both CallAt and AllLines it holds that for no list element is LineNumbers an
empty list; such elements have been removed. The constants of component and the
integers of LineNumbers are sorted and without duplicates.
remove_application(Xref, Applications) -> ok | Error
Types:
Applications = application() | [application()]
Error = {error, module(), Reason}
Reason = {no_such_application, application()}
Xref = xref()
Removes applications and their modules and module data from an Xref server.
remove_module(Xref, Modules) -> ok | Error
Types:
Error = {error, module(), Reason}
Modules = module() | [module()]
Reason = {no_such_module, module()}
Xref = xref()
Removes analyzed modules and module data from an Xref server.
remove_release(Xref, Releases) -> ok | Error
Types:
Error = {error, module(), Reason}
Reason = {no_such_release, release()}
Releases = release() | [release()]
Xref = xref()
Removes releases and their applications, modules and module data from an Xref
server.
replace_application(Xref, Application, Directory [, Options]) -> {ok, application()} |
Error
Types:
Application = application()
Directory = directory()
Error = {error, module(), Reason}
Options = [Option] | Option
Option = {builtins, bool()} | {verbose, bool()} | {warnings, bool()}
Reason = {no_such_application, application()} | - see also add_application -
Xref = xref()
Replaces the modules of an application with other modules read from an application
directory. Release membership of the application is retained. Note that the name of
the application is kept; the name of the given directory is not used.
replace_module(Xref, Module, File [, Options]) -> {ok, module()} | Error
Types:
Error = {error, module(), Reason}
File = file()
Module = module()
Options = [Option] | Option
Option = {verbose, bool()} | {warnings, bool()}
ReadModule = module()
Reason = {module_mismatch, module(), ReadModule} | {no_such_module, module()} |
- see also add_module -
Xref = xref()
Replaces module data of an analyzed module with data read from a BEAM file.
Application membership of the module is retained, and so is the value of the
builtins option of the module. An error is returned if the name of the read module
differs from the given module.
The update function is an alternative for updating module data of recompiled
modules.
set_default(Xref, Option, Value) -> {ok, OldValue} | Error
set_default(Xref, OptionValues) -> ok | Error
Types:
Error = {error, module(), Reason}
OptionValues = [OptionValue] | OptionValue
OptionValue = {Option, Value}
Option = builtins | recurse | verbose | warnings
Reason = {invalid_options, term()}
Value = bool()
Xref = xref()
Sets the default value of one or more options. The options that can be set this way
are:
* builtins, with initial default value false;
* recurse, with initial default value false;
* verbose, with initial default value false;
* warnings, with initial default value true.
The initial default values are set when creating an Xref server.
set_library_path(Xref, LibraryPath [, Options]) -> ok | Error
Types:
Error = {error, module(), Reason}
LibraryPath = library_path()
Options = [Option] | Option
Option = {verbose, bool()}
Reason = {invalid_options, term()} | {invalid_path, term()}
Xref = xref()
Sets the library path. If the given path is a list of directories, the set of
library modules is determined by choosing the first module encountered while
traversing the directories in the given order, for those modules that occur in more
than one directory. By default, the library path is an empty list.
The library path code_path is used by the functions m/1 and d/1, but can also be
set explicitly. Note however that the code path will be traversed once for each
used library module while setting up module data. On the other hand, if there are
only a few modules that are used but not analyzed, using code_path may be faster
than setting the library path to code:get_path().
If the library path is set to code_path, the set of library modules is not
determined, and the info functions will return empty lists of library modules.
start(NameOrOptions) -> Return
Types:
NameOrOptions = Name | Options
Name = atom()
Options = [Option] | Option
Option = {xref_mode, mode()} | term()
Return = {ok, pid()} | {error, {already_started, pid()}}
Creates an Xref server. The process may optionally be given a name. The default
mode is functions. Options that are not recognized by Xref are passed on to
gen_server:start/4.
start(Name, Options) -> Return
Types:
Name = atom()
Options = [Option] | Option
Option = {xref_mode, mode()} | term()
Return = {ok, pid()} | {error, {already_started, pid()}}
Creates an Xref server with a given name. The default mode is functions. Options
that are not recognized by Xref are passed on to gen_server:start/4.
stop(Xref)
Types:
Xref = xref()
Stops an Xref server.
update(Xref [, Options]) -> {ok, Modules} | Error
Types:
Error = {error, module(), Reason}
Modules = [module()]
Options = [Option] | Option
Option = {verbose, bool()} | {warnings, bool()}
Reason = {invalid_options, term()} | {module_mismatch, module(), ReadModule} | -
see also add_module -
Xref = xref()
Replaces the module data of all analyzed modules the BEAM files of which have been
modified since last read by an add function or update. Application membership of
the modules is retained, and so is the value of the builtins option. Returns a
sorted list of the names of the replaced modules.
variables(Xref [, Options]) -> {ok, [VariableInfo]}
Types:
Options = [Option] | Option
Option = predefined | user | {verbose, bool()}
Reason = {invalid_options, term()}
VariableInfo = {predefined, [variable()]} | {user, [variable()]}
Xref = xref()
Returns a sorted lists of the names of the variables of an Xref server. The default
is to return the user variables only.
SEE ALSO
beam_lib(3erl), digraph(3erl), digraph_utils(3erl), re(3erl), TOOLS User's Guide