1dialyzer(3) Erlang Module Definition dialyzer(3)
2
6 dialyzer - Dialyzer, a DIscrepancy AnaLYZer for ERlang programs.
7
10 Dialyzer is a static analysis tool that identifies software discrepan‐
11 cies, such as definite type errors, code that has become dead or
12 unreachable because of programming error, and unnecessary tests, in
13 single Erlang modules or entire (sets of) applications.
14 Dialyzer starts its analysis from either debug-compiled BEAM bytecode
16 or from Erlang source code. The file and line number of a discrepancy
17 is reported along with an indication of what the discrepancy is about.
18 Dialyzer bases its analysis on the concept of success typings, which
19 allows for sound warnings (no false positives).
20
22 Dialyzer has a command-line version for automated use. This section
23 provides a brief description of the options. The same information can
24 be obtained by writing the following in a shell:
25 dialyzer --help
27 For more details about the operation of Dialyzer, see section Using
29 Dialyzer from the GUI in the User's Guide.
30 Exit status of the command-line version:
32 0:
34 No problems were found during the analysis and no warnings were
35 emitted.
36 1:
38 Problems were found during the analysis.
39 2:
41 No problems were found during the analysis, but warnings were emit‐
42 ted.
43 Usage:
45 dialyzer [--add_to_plt] [--apps applications] [--build_plt]
47 [--check_plt] [-Ddefine]* [-Dname] [--dump_callgraph file]
48 [files_or_dirs] [--fullpath] [--get_warnings] [--gui] [--help]
49 [-I include_dir]* [--no_check_plt] [--no_native]
50 [--no_native_cache] [-o outfile] [--output_plt file] [-pa dir]*
51 [--plt plt] [--plt_info] [--plts plt*] [--quiet] [-r dirs]
52 [--raw] [--remove_from_plt] [--shell] [--src] [--statistics]
53 [--verbose] [--version] [-Wwarn]*
54 Note:
56 * denotes that multiple occurrences of the option are possible.
57 Options:
60 --add_to_plt:
62 The PLT is extended to also include the files specified with -c and
63 -r. Use --plt to specify which PLT to start from, and --output_plt
64 to specify where to put the PLT. Notice that the analysis possibly
65 can include files from the PLT if they depend on the new files.
66 This option only works for BEAM files.
67 --apps applications:
69 This option is typically used when building or modifying a PLT as
70 in:
71 dialyzer --build_plt --apps erts kernel stdlib mnesia ...
73 to refer conveniently to library applications corresponding to the
75 Erlang/OTP installation. However, this option is general and can
76 also be used during analysis to refer to Erlang/OTP applications.
77 File or directory names can also be included, as in:
78 dialyzer --apps inets ssl ./ebin ../other_lib/ebin/my_module.beam
80 --build_plt:
82 The analysis starts from an empty PLT and creates a new one from
83 the files specified with -c and -r. This option only works for BEAM
84 files. To override the default PLT location, use --plt or --out‐
85 put_plt.
86 --check_plt:
88 Check the PLT for consistency and rebuild it if it is not up-to-
89 date.
90 -Dname (or -Dname=value):
92 When analyzing from source, pass the define to Dialyzer. (**)
93 --dump_callgraph file:
95 Dump the call graph into the specified file whose format is deter‐
96 mined by the filename extension. Supported extensions are: raw,
97 dot, and ps. If something else is used as filename extension,
98 default format .raw is used.
99 files_or_dirs (for backward compatibility also as -c files_or_dirs):
101 Use Dialyzer from the command line to detect defects in the speci‐
102 fied files or directories containing .erl or .beam files, depending
103 on the type of the analysis.
104 --fullpath:
106 Display the full path names of files for which warnings are emit‐
107 ted.
108 --get_warnings:
110 Make Dialyzer emit warnings even when manipulating the PLT. Warn‐
111 ings are only emitted for files that are analyzed.
112 --gui:
114 Use the GUI.
115 --help (or -h):
117 Print this message and exit.
118 -I include_dir:
120 When analyzing from source, pass the include_dir to Dialyzer. (**)
121 --no_check_plt:
123 Skip the PLT check when running Dialyzer. This is useful when work‐
124 ing with installed PLTs that never change.
125 --no_native (or -nn):
127 Bypass the native code compilation of some key files that Dialyzer
128 heuristically performs when dialyzing many files. This avoids the
129 compilation time, but can result in (much) longer analysis time.
130 --no_native_cache:
132 By default, Dialyzer caches the results of native compilation in
133 directory $XDG_CACHE_HOME/erlang/dialyzer_hipe_cache.
134 XDG_CACHE_HOME defaults to $HOME/.cache. Use this option to disable
135 caching.
136 -o outfile (or --output outfile):
138 When using Dialyzer from the command line, send the analysis
139 results to the specified outfile rather than to stdout.
140 --output_plt file:
142 Store the PLT at the specified file after building it.
143 -pa dir:
145 Include dir in the path for Erlang. This is useful when analyzing
146 files that have -include_lib() directives.
147 --plt plt:
149 Use the specified PLT as the initial PLT. If the PLT was built dur‐
150 ing setup, the files are checked for consistency.
151 --plt_info:
153 Make Dialyzer print information about the PLT and then quit. The
154 PLT can be specified with --plt(s).
155 --plts plt*:
157 Merge the specified PLTs to create the initial PLT. This requires
158 that the PLTs are disjoint (that is, do not have any module appear‐
159 ing in more than one PLT). The PLTs are created in the usual way:
160 dialyzer --build_plt --output_plt plt_1 files_to_include
162 dialyzer --build_plt --output_plt plt_n files_to_include
163 They can then be used in either of the following ways:
165 dialyzer files_to_analyze --plts plt_1 ... plt_n
167 or
169 dialyzer --plts plt_1 ... plt_n -- files_to_analyze
171 Notice the -- delimiter in the second case.
173 --quiet (or -q):
175 Make Dialyzer a bit more quiet.
176 -r dirs:
178 Same as files_or_dirs, but the specified directories are searched
179 recursively for subdirectories containing .erl or .beam files in
180 them, depending on the type of analysis.
181 --raw:
183 When using Dialyzer from the command line, output the raw analysis
184 results (Erlang terms) instead of the formatted result. The raw
185 format is easier to post-process (for example, to filter warnings
186 or to output HTML pages).
187 --remove_from_plt:
189 The information from the files specified with -c and -r is removed
190 from the PLT. Notice that this can cause a reanalysis of the
191 remaining dependent files.
192 --shell:
194 Do not disable the Erlang shell while running the GUI.
195 --src:
197 Override the default, which is to analyze BEAM files, and analyze
198 starting from Erlang source code instead.
199 --statistics:
201 Print information about the progress of execution (analysis phases,
202 time spent in each, and size of the relative input).
203 --verbose:
205 Make Dialyzer a bit more verbose.
206 --version (or -v):
208 Print the Dialyzer version and some more information and exit.
209 -Wwarn:
211 A family of options that selectively turn on/off warnings. (For
212 help on the names of warnings, use dialyzer -Whelp.) Notice that
213 the options can also be specified in the file with a -dialyzer()
214 attribute. For details, see section Requesting or Suppressing Warn‐
215 ings in Source Files.
216 Note:
218 ** options -D and -I work both from the command line and in the Dia‐
219 lyzer GUI; the syntax of defines and includes is the same as that used
220 by erlc(1).
221 Warning options:
224 -Werror_handling (***):
226 Include warnings for functions that only return by an exception.
227 -Wno_behaviours:
229 Suppress warnings about behavior callbacks that drift from the pub‐
230 lished recommended interfaces.
231 -Wno_contracts:
233 Suppress warnings about invalid contracts.
234 -Wno_fail_call:
236 Suppress warnings for failing calls.
237 -Wno_fun_app:
239 Suppress warnings for fun applications that will fail.
240 -Wno_improper_lists:
242 Suppress warnings for construction of improper lists.
243 -Wno_match:
245 Suppress warnings for patterns that are unused or cannot match.
246 -Wno_missing_calls:
248 Suppress warnings about calls to missing functions.
249 -Wno_opaque:
251 Suppress warnings for violations of opacity of data types.
252 -Wno_return:
254 Suppress warnings for functions that will never return a value.
255 -Wno_undefined_callbacks:
257 Suppress warnings about behaviors that have no -callback attributes
258 for their callbacks.
259 -Wno_unused:
261 Suppress warnings for unused functions.
262 -Wrace_conditions (***):
264 Include warnings for possible race conditions. Notice that the
265 analysis that finds data races performs intra-procedural data flow
266 analysis and can sometimes explode in time. Enable it at your own
267 risk.
268 -Wunderspecs (***):
270 Warn about underspecified functions (the specification is strictly
271 more allowing than the success typing).
272 -Wunknown (***):
274 Let warnings about unknown functions and types affect the exit sta‐
275 tus of the command-line version. The default is to ignore warnings
276 about unknown functions and types when setting the exit status.
277 When using Dialyzer from Erlang, warnings about unknown functions
278 and types are returned; the default is not to return these warn‐
279 ings.
280 -Wunmatched_returns (***):
282 Include warnings for function calls that ignore a structured return
283 value or do not match against one of many possible return value(s).
284 The following options are also available, but their use is not recom‐
286 mended (they are mostly for Dialyzer developers and internal debug‐
287 ging):
288 -Woverspecs (***):
290 Warn about overspecified functions (the specification is strictly
291 less allowing than the success typing).
292 -Wspecdiffs (***):
294 Warn when the specification is different than the success typing.
295 Note:
297 *** denotes options that turn on warnings rather than turning them off.
298
301 Dialyzer can be used directly from Erlang. Both the GUI and the com‐
302 mand-line versions are also available. The options are similar to the
303 ones given from the command line, see section Using Dialyzer from the
304 Command Line.
305
307 Attribute -dialyzer() can be used for turning off warnings in a module
308 by specifying functions or warning options. For example, to turn off
309 all warnings for the function f/0, include the following line:
310 -dialyzer({nowarn_function, f/0}).
312 To turn off warnings for improper lists, add the following line to the
314 source file:
315 -dialyzer(no_improper_lists).
317 Attribute -dialyzer() is allowed after function declarations. Lists of
319 warning options or functions are allowed:
320 -dialyzer([{nowarn_function, [f/0]}, no_improper_lists]).
322 Warning options can be restricted to functions:
324 -dialyzer({no_improper_lists, g/0}).
326 -dialyzer({[no_return, no_match], [g/0, h/0]}).
328 For help on the warning options, use dialyzer -Whelp. The options are
330 also enumerated, see function gui/1 below (WarnOpts).
331 Note:
333 Warning option -Wrace_conditions has no effect when set in source
334 files.
335 Attribute -dialyzer() can also be used for turning on warnings. For
338 example, if a module has been fixed regarding unmatched returns, adding
339 the following line can help in assuring that no new unmatched return
340 warnings are introduced:
341 -dialyzer(unmatched_returns).
343
345 format_warning(Msg) -> string()
346 Types:
348 Msg = {Tag, Id, msg()}
350 See run/1.
351 Get a string from warnings as returned by run/1.
353 gui() -> ok | {error, Msg}
355 gui(OptList) -> ok | {error, Msg}
356 Types:
358 OptList
360 See below.
361 Dialyzer GUI version.
363 OptList :: [Option]
365 Option :: {files, [Filename :: string()]}
366 | {files_rec, [DirName :: string()]}
367 | {defines, [{Macro :: atom(), Value :: term()}]}
368 | {from, src_code | byte_code}
369 %% Defaults to byte_code
370 | {init_plt, FileName :: string()}
371 %% If changed from default
372 | {plts, [FileName :: string()]}
373 %% If changed from default
374 | {include_dirs, [DirName :: string()]}
375 | {output_file, FileName :: string()}
376 | {output_plt, FileName :: string()}
377 | {check_plt, boolean()},
378 | {analysis_type, 'succ_typings' |
379 'plt_add' |
380 'plt_build' |
381 'plt_check' |
382 'plt_remove'}
383 | {warnings, [WarnOpts]}
384 | {get_warnings, bool()}
385 WarnOpts :: error_handling
387 | no_behaviours
388 | no_contracts
389 | no_fail_call
390 | no_fun_app
391 | no_improper_lists
392 | no_match
393 | no_missing_calls
394 | no_opaque
395 | no_return
396 | no_undefined_callbacks
397 | no_unused
398 | race_conditions
399 | underspecs
400 | unknown
401 | unmatched_returns
402 | overspecs
403 | specdiffs
404 plt_info(string()) -> {'ok', [{atom(), any()}]} | {'error', atom()}
406 Returns information about the specified PLT.
408 run(OptList) -> Warnings
410 Types:
412 OptList
414 See gui/0,1.
415 Warnings
416 See below.
417 Dialyzer command-line version.
419 Warnings :: [{Tag, Id, Msg}]
421 Tag :: 'warn_behaviour'
422 | 'warn_bin_construction'
423 | 'warn_callgraph'
424 | 'warn_contract_not_equal'
425 | 'warn_contract_range'
426 | 'warn_contract_subtype'
427 | 'warn_contract_supertype'
428 | 'warn_contract_syntax'
429 | 'warn_contract_types'
430 | 'warn_failing_call'
431 | 'warn_fun_app'
432 | 'warn_matching'
433 | 'warn_non_proper_list'
434 | 'warn_not_called'
435 | 'warn_opaque'
436 | 'warn_race_condition'
437 | 'warn_return_no_exit'
438 | 'warn_return_only_exit'
439 | 'warn_umatched_return'
440 | 'warn_undefined_callbacks'
441 | 'warn_unknown'
442 Id = {File :: string(), Line :: integer()}
443 Msg = msg() -- Undefined
444Ericsson AB dialyzer 3.3.2 dialyzer(3)