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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.
OL:
Functions with an attribute tag on_load (*).
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.
* OL is a subset of F.
* 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 BinaryGraphOp Expression
* Expression ::= UnaryGraphOp Expression
* UnaryGraphOp ::= components | condensation
* BinaryGraphOp ::= 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