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<!DOCTYPE chapter SYSTEM "chapter.dtd">
<chapter>
<header>
<copyright>
<year>2006</year><year>2010</year>
<holder>Ericsson AB. All Rights Reserved.</holder>
</copyright>
<legalnotice>
The contents of this file are subject to the Erlang Public License,
Version 1.1, (the "License"); you may not use this file except in
compliance with the License. You should have received a copy of the
Erlang Public License along with this software. If not, it can be
retrieved online at http://www.erlang.org/.
Software distributed under the License is distributed on an "AS IS"
basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
the License for the specific language governing rights and limitations
under the License.
</legalnotice>
<title>Dialyzer Release Notes</title>
<prepared>otp_appnotes</prepared>
<docno>nil</docno>
<date>nil</date>
<rev>nil</rev>
<file>notes.xml</file>
</header>
<p>This document describes the changes made to the Dialyzer
application.</p>
<section><title>Dialyzer 2.3.1</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>
Eliminated warnings for auto-imported BIF clashes.</p>
<p>
Own Id: OTP-8840</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 2.3.0</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>
Various changes to dialyzer-related files for R14.</p>
<p>
- Dialyzer properly supports the new attribute
-export_type and checks that remote types only refer to
exported types. A warning is produced if some
files/applications refer to types defined in modules
which are neither in the PLT nor in the analyzed
applications.</p>
<p>
- Support for detecting data races involving whereis/1
and unregister/1.</p>
<p>
- More precise identification of the reason(s) why a
record construction violates the types declared for its
fields.</p>
<p>
- Fixed bug in the handling of the 'or' guard.</p>
<p>
- Better handling of the erlang:element/2 BIF.</p>
<p>
- Complete handling of Erlang BIFs.</p>
<p>
Own Id: OTP-8699</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 2.2.0</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>Much better support for opaque types (thanks to Manouk
Manoukian).</p>
<p>Added support for recursive types (experimental).</p>
<p>Added support for parameterized modules.</p>
<p>Dialyzer now warns when -specs state that a function
returns some type when in fact it does not.</p>
<p>Added <c>--no_native</c> (<c>-nn</c>) option so that
the user can bypass the native code compilation that
dialyzer heuristically performs when dialyzing many
files.</p>
<p>Fixed minor bug in the dialyzer script allowing the
--wx option to bring up the wx-based GUI regardless of
its placement in the options list.</p>
<p>Options --apps and -Wrace_conditions, which were added
in the previous version, are now properly documented in
the manual.</p>
<p>
Own Id: OTP-8464</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 2.1.0</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>
The documentation is now built with open source tools
(xsltproc and fop) that exists on most platforms. One
visible change is that the frames are removed.</p>
<p>
Own Id: OTP-8201</p>
</item>
<item>
<p>
Dialyzer can statically detect some kinds of data races
in Erlang programs. Use the new option -Wrace_conditions
to enable the race analysis. The technique is described
in a paper which is available at:
http://www.it.uu.se/research/group/hipe/dialyzer/publications/races.pdf</p>
<p>
Added support for packages (thanks to Maria Christakis).</p>
<p>
There has been a major change in the default mode of
Dialyzer. Previously, the default mode was the GUI, while
now it is the command line. As a result of this change,
it is now possible to analyze a set of files/dirs with
the command: </p><list> <item>dialyzer file1 ...
fileN</item> </list><p> In other words, the -c
(--command-line) option is no longer necessary, though it
will be retained for some time for backwards
compatibility. To start dialyzer's GUI use either of the
following commands: </p><list> <item>dialyzer --gui %%
for the old gs-based GUI</item> <item>dialyzer --wx %%
for the new wx-based GUI (where available)</item>
</list><p></p>
<p>
There is a new option --apps which allows the user to
easily refer to Erlang/OTP applications and include them
in the analysis or in the building of the PLT. For
example, we recommend building the PLT with: </p><list>
<item>dialyzer --build_plt --apps erts kernel stdlib
mnesia ...</item> </list><p></p>
<p>
The new option can also take absolute file names as well
as applications. Note that the application versions that
will be included in the PLT are those that correspond to
the Erlang/OTP system which is used.</p>
<p>
Dialyzer has a new wxWidgets based GUI (thanks to Elli
Frangaki) for platforms where the wx application is
available.</p>
<p>
Own Id: OTP-8300</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 2.0.0</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>There is a major addition to the capabilities of
dialyzer, worthy of bumping the version number. Starting
with this version, dialyzer not only accepts but also
properly processes remote types (i.e., types of the form
ModuleName:TypeName()). Previous dialyzer versions only
accepted this notation in -type and -spec declarations,
but effectively ignored its information by mapping remote
types to the type any(). In contrast, starting with this
version, remote types are used in the analysis and are
also stored in the PLTs. (This addition changes the
format of PLTs and requires rebuilding any PLTs created
by an older dialyzer version.) Note that dialyzer will
complain and abort the analysis of a set of modules if it
needs to process a remote type without a definition
(either because the module does not include a definition
of the type or the module is not included in the
analysis). We may relax this restriction in a future
version.</p>
<p>Fixed minor issue with dialyzer:run/1 crashing (upon
its return) when used for adding type information to an
existing PLT.</p>
<p>Fixed minor but quite annoying issues in dialyzer's
GUI.</p>
<p>
Own Id: OTP-8187</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.9.2</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>Fixed problem with type inference going into an
infinite loop when analyzing a strongly connected
component of functions that do not return but also
contain an erroneous call which makes them fail and be
assigned the type none() instead of the type unit().</p>
<p>More accurate type information for some BIFs and
library files.</p>
<p>Introduced boolean() as the `official' name for the
type was so far known as bool(). The latter is still
accepted as well as boolean().</p>
<p>
Own Id: OTP-8037</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.9.1</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>Has better handling of opaque types.</p>
<p>The handling of UTF segments of bitstreams has been
significantly strengthened and revised. In all
probability, now it is correct.</p>
<p>
Own Id: OTP-7958</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.9.0</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>The analysis accepts opaque type declarations and
detects violations of opaqueness of terms of such types.
Starting with R13, many Erlang/OTP standard libraries
(array, dict, digraph, ets, gb_sets, gb_trees, queue, and
sets) contain opaque type declarations of their main data
types. Dialyzer will spit out warnings in code that
explicitly depends on the structure of these terms.</p>
<p>Added support for handling UTF segments in bitstreams
and for detecting obvious type errors in these segments.
Warning: This code is not terribly tested though since
there are very few Erlang programs which use
Unicode-based binaries - not surprising since this is a
new language feature of R13.</p>
<p>Strengthened the discrepancy identification when
testing for equality and matching between terms of
different types. This detects more bugs in code.</p>
<p>Added warning for M:F(...) calls where M is not a
module term and F is not an atom. Previously, such calls
where found to fail but the reason for the failure was
not reported.</p>
<p>Added a convenient shorthand for the --no_check_plt
option (-n).</p>
<p>Added the --dump_callgraph option for dumping the
callgraph of all files that are analyzed into a specified
file. The callgraph either be dumped in raw format, in
.dot format, or converted to a .ps (postscript) file.
Note that in large callgraphs the generated postscript
file might not be interpretable by Ghostview. (Thanks to
Ilya Khlopotov for the initial version of this
functionality.)</p>
<p>
Own Id: OTP-7864</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.8.3</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>Added the <c>--no_check_plt</c> option that makes the
startup time faster when working with stable PLTs that do
not change.</p>
<p>Changed the phrasing of some warnings so that they do
not cause confusion to some users and correspond better
to reality.</p>
<p>
Own Id: OTP-7632</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.8.2</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>
Minor updates.</p>
<p>
Own Id: OTP-7522</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.8.1</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>
There is new <c>--raw</c> option for Dialyzer to output
the result of the analysis in Erlang term, to facilitate
later filtering and/or formatting.</p>
<p>
Own Id: OTP-7386</p>
</item>
<item>
<p>The return type of the Erlang interface dialyzer:run/1
has changed to only return a list of warnings. If
something goes wrong dialyzer dies with an exception.</p>
<p>The handling of the PLT is now more flexible. There is
no longer any default PLT included with OTP. Please
consult the manual for the changes.</p>
<p>
Own Id: OTP-7389</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.8.0</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>Dialyzer's analysis is from now on exclusively based
on success typings. In particular, support for options
<c>--old_style</c> and <c>--dataflow</c> has been
discontinued.</p>
<p>Better and more aggressive handling of type
information in records.</p>
<p>Dialyzer has a new warning option
<c>-Wunmatched_returns</c> which warns for function calls
that ignore the return value. This catches many common
programming errors (e.g. calling <c>file:close/1</c> and
not checking for the absence of errors), interface
discrepancies (e.g. a function returning multiple values
when in reality the function is void and only called for
its side-effects), calling the wrong function (e.g.
<c>io_lib:format/1</c> instead of <c>io:format/1</c>),
and even possible performance defects (e.g. unnecessarily
constructing a list using a list comprehension instead of
using <c>lists:foreach/2</c>). Whenever a function
returns a single atomic value (e.g. 'ok' or pid()), the
warning is suppressed. This allows for "void" functions
(returning a single atom like 'ok') or for calls to
certain builtins like <c>spawn</c>. Because not all calls
which ignore the return value are discrepancies, the
option is off by default and has to be explicitly
requested by the user. But we recommend it
nevertheless.</p>
<p>Some warning options (<c>-Wno_comp</c>,
<c>-Wno_guards</c>, <c>-Wno_unsafe_beam</c>, etc.) which
could be used when analyzing bytecode produced by an old
BEAM compiler have been removed.</p>
<p>
Own Id: OTP-7241</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.7.2</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>
The warnings returned by the Erlang interface now
contains a tag describing the type of warning.</p>
<p>
*** POTENTIAL INCOMPATIBILITY ***</p>
<p>
Own Id: OTP-7134</p>
</item>
</list>
</section>
</section>
<section><title>Dialyzer 1.7.1</title>
<section><title>Improvements and New Features</title>
<list>
<item>
<p>Use of success typings is now default, is robust and
detects significantly more errors than in previous
versions.</p>
<p>Dialyzer now accepts and takes into account type
information in record declarations and in contracts --
see related paper in Erlang'07 workshop. Various OTP
applications (e.g. stdlib and kernel) are partially
annotated with appropriate contracts specifying types
information for their functions.</p>
<p>The type previously known as unit() has been renamed
to no_return(). Its use in a contract as the return type
of a function now silences off the "function has no local
return" dialyzer warning without use of the corresponding
option.</p>
<p>
Own Id: OTP-6997</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.7.0</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Minor Makefile changes.</p>
<p>Own Id: OTP-6689</p>
</item>
<item>
<p>Dialyzer can now use success typings to find
discrepancies. As a consequence significantly more
discrepancies are detected. The downside is that the
analysis takes about 2 to 2.5 times longer than in
previous versions, and may also result in some warnings
that might be harder to interpret even though they are
correct. This has been a major change, worth of
increasing the version number.</p>
<p>New command-line options:</p>
<p>--succ_typings Use the success typings analysis.</p>
<p>--dataflow (default) Use the previous analysis.</p>
<p>The new type unit() has been introduced to handle the
return type of non-terminating functions such as
servers.</p>
<p>Dialyzer's code server uses a compressed
representation and the analysis requires significantly
less memory than in previous versions.</p>
<p>Own Id: OTP-6736</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.6.0</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Dialyzer (in the modes where either source or BEAM
code which contains debug_info is analyzed) spits out
line information for all discrepancies. This has been a
major change, worth of increasing the version number.</p>
<p>We warn users that *considerably* more discrepancies
are identified by this version of Dialyzer compared with
previous ones and applications. If, for some reason,
warnings generated by previous versions of Dialyzer are
preferable, the command line option --old_style can be
employed.</p>
<p>Own Id: OTP-6546</p>
</item>
<item>
<p>Dialyzer handles term comparison operators more
precisely and is able to identify more discrepancies in
'if' or 'case' statements with comparisons.</p>
<p></p>
<p>Dialyzer has more precise type information for many
standard OTP functions.</p>
<p>Own Id: OTP-6547</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.5.1</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Updated the chapter "More on the Persistent Lookup Table
(PLT)" in Dialyzer User's Guide and added information on
how to use Dialyzer from Erlang to <c><![CDATA[dialyzer(3)]]></c>.
Also, the Dialyzer text files used by its GUI are now
included in the Erlang/OTP release.</p>
<p>Own Id: OTP-6361</p>
</item>
<item>
<p>New options <c><![CDATA[--check_init_plt]]></c> and
<c><![CDATA[--verbose]]></c>.</p>
<p>Improvements in the analysis (meaning that this
version can find more discrepancies than the previous
version).</p>
<p>Own Id: OTP-6421</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.5.0</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Dialyzer's building of PLT is based on a different
type inference algorithm. More specifically, Dialyzer
uses inference of refined success typings to infer
function prototypes. As a result, Dialyzer bases its
analysis on a significantly more powerful basis and thus
is able to detect more discrepancies. The downside is
that building the PLT is a considerably slower process.
We will work on improving that.</p>
<p>Dialyzer takes into account the BEAM compiler
directive <c><![CDATA[-compile({nowarn_unused_function, {F,A}}).]]></c> and then suppresses the warning that
function F/A will never be called.</p>
<p>Dialyzer's default initial PLT now also includes
"mnesia".</p>
<p>Own Id: OTP-6304</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.4.2</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Improvements in PLT management.</p>
<p>Own Id: OTP-6128</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.4.1</title>
<section>
<title>Fixed Bugs and Malfunctions</title>
<list type="bulleted">
<item>
<p>Some minor changes.</p>
</item>
</list>
</section>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Some minor changes.</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.4.0</title>
<section>
<title>Fixed Bugs and Malfunctions</title>
<list type="bulleted">
<item>
<p>Changes for Dialyzer to work with Erlang/OTP R10B-10.</p>
</item>
</list>
</section>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Dialyzer's analysis is significantly faster as it uses a global function
call-graph for obtaining type signatures for all analyzed functions.</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.3.1</title>
<section>
<title>Fixed Bugs and Malfunctions</title>
<list type="bulleted">
<item>
<p>Small changes for Dialyzer to work with Erlang/OTP R10B-5.</p>
</item>
<item>
<p>Fixed a small buglet in the analysis; this affected one of HiPE's files.</p>
</item>
</list>
</section>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Modified setup script for execution under Cygwin (patch by Vlad Dumitrescu).</p>
</item>
<item>
<p>Added command line option --no_warn_on_inline.</p>
</item>
<item>
<p>Dialyzer now explicitly warns when modules with the same name
but from different dirs are being analyzed (contribution by Ulf Wiger).</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.3.0</title>
<section>
<title>Fixed Bugs and Malfunctions</title>
<list type="bulleted">
<item>
<p>Fixed a number of false positives that Dialyzer 1.2.0 was spitting out.</p>
</item>
</list>
</section>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Requires the presence of an Erlang/OTP R10B-4 system.</p>
</item>
<item>
<p>Dialyzer is significantly (approx 40%) faster since it now uses 'ets'
rather than 'dets' for its PLT.</p>
</item>
<item>
<p>Slightly improved the precision of the analysis.</p>
</item>
<item>
<p>In the GUI version, Dialyzer now reports the list of modules that should
be included in the modules to analyze in order to possibly improve
the accuracy of the reported results.</p>
</item>
<item>
<p>Some more information is displayed when calling a function or closure
with arguments of the wrong type.</p>
</item>
<item>
<p>The record guard now allows discrepancies involving tuples that are known
to be records to be displayed as #rec{} rather than {'rec',_,...,_}</p>
</item>
<item>
<p>Added -q option which makes the command-line version of Dialyzer
a bit more silent.</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.2.0</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Dialyzer works with the open source and commercial versions of Erlang/OTP
R10B-2 on all platforms (i.e., HiPE support is not a prerequisite anymore).</p>
</item>
<item>
<p>Whenever a .beam file contains abstract code (i.e., has been compiled
with the +debug_info option), the analysis starts from this code rather
than from BEAM bytecode -- this makes the results identical to those
obtained by analysis starting from source code.
(This is a contribution from Bjorn Gustavsson - Thanks!)</p>
</item>
<item>
<p>Added -pa command line option for easier handling of -include_lib()
directives in source code.</p>
</item>
<item>
<p>Includes all changes added in v1.1.1; see below. The "Add Recursively"
functionality is also available in the command-line mode (-r option).</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.1.1</title>
<section>
<title>Fixed Bugs and Malfunctions</title>
<list type="bulleted">
<item>
<p>Fixed problems using the shell script on Solaris machines.</p>
</item>
<item>
<p>Fixed small inconsistencies in Dialyzer's documentation and help.</p>
</item>
</list>
</section>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>The command-line mode of Dialyzer spits discrepancies in stdout
by default and returns a numeric value indicating its exit status.</p>
</item>
<item>
<p>Added "Add Recursively" button contributed by Martin Bjorklund (thanks!).</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.1.0</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Dialyzer works with the open source version of Erlang/OTP R10B-1 (on
platforms where HiPE support is available) and it does not require
installation of a customized Erlang/OTP system anymore.</p>
</item>
<item>
<p>Dialyzer comes with an extensive command-line interface, in addition
to an enhanced GUI.</p>
</item>
<item>
<p>Analysis can start from source code (through Core Erlang) as well as
from BEAM bytecode.</p>
</item>
<item>
<p>Dialyzer finds considerably more discrepancies in Erlang code than
previous versions.</p>
</item>
<item>
<p>Added ability to selectively turn on/off different warning categories.</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.0.1</title>
<section>
<title>Fixed Bugs and Malfunctions</title>
<list type="bulleted">
<item>
<p>Fixed major bug of v1.0.0 which caused the analysis to stop prematurely
(i.e., without properly reaching fixpoint) when analyzing more than one
module. This did not affect correctness of the results, but lost many
opportunities to detect discrepancies.</p>
</item>
</list>
</section>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Performance improvements in the analysis.</p>
</item>
</list>
</section>
</section>
<section>
<title>Dialyzer 1.0.0</title>
<section>
<title>Improvements and New Features</title>
<list type="bulleted">
<item>
<p>Initial Dialyzer version: Analysis starts from BEAM bytecode only and
only a GUI version is available. Dialyzer reports discrepancies in the
use of the "sequential" part of Erlang. To be used, Dialyzer requires
the presence of a specific snapshot of Erlang/OTP which can be obtained
from Dialyzer's homepage.</p>
</item>
</list>
</section>
</section>
</chapter>
