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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
"http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
<book>
<bookinfo>
<title>Cppcheck 1.75</title>
<date>2016-08-13</date>
</bookinfo>
<chapter>
<title>Introduction</title>
<para>Cppcheck is an analysis tool for C/C++ code. Unlike C/C++ compilers
and many other analysis tools, it doesn't detect syntax errors. Instead,
Cppcheck detects the types of bugs that the compilers normally fail to
detect. The goal is no false positives.</para>
<para>Supported code and platforms:</para>
<itemizedlist>
<listitem>
<para>You can check non-standard code that includes various compiler
extensions, inline assembly code, etc.</para>
</listitem>
<listitem>
<para>Cppcheck should be compilable by any C++ compiler that handles
the latest C++ standard.</para>
</listitem>
<listitem>
<para>Cppcheck should work on any platform that has sufficient CPU and
memory.</para>
</listitem>
</itemizedlist>
<para>Please understand that there are limits of Cppcheck. Cppcheck is
rarely wrong about reported errors. But there are many bugs that it
doesn't detect.</para>
<para>You will find more bugs in your software by testing your software
carefully, than by using Cppcheck. You will find more bugs in your
software by instrumenting your software, than by using Cppcheck. But
Cppcheck can still detect some of the bugs that you miss when testing and
instrumenting your software.</para>
</chapter>
<chapter>
<title>Getting started</title>
<section>
<title>First test</title>
<para>Here is a simple code</para>
<programlisting>int main()
{
char a[10];
a[10] = 0;
return 0;
}</programlisting>
<para>If you save that into <filename>file1.c</filename> and
execute:</para>
<programlisting>cppcheck file1.c</programlisting>
<para>The output from cppcheck will then be:</para>
<programlisting>Checking file1.c...
[file1.c:4]: (error) Array 'a[10]' index 10 out of bounds</programlisting>
</section>
<section>
<title>Checking all files in a folder</title>
<para>Normally a program has many source files. And you want to check
them all. Cppcheck can check all source files in a directory:</para>
<programlisting>cppcheck path</programlisting>
<para>If "path" is a folder then cppcheck will recursively check all
source files in this folder.</para>
<programlisting>Checking path/file1.cpp...
1/2 files checked 50% done
Checking path/file2.cpp...
2/2 files checked 100% done</programlisting>
</section>
<section>
<title>Check files manually or use project file</title>
<para>With Cppcheck you can check files manually, by specifying
files/paths to check and settings. Or you can use a project file
(cmake/visual studio).</para>
<para>Using the project file is quicker since it requires very little
configuration from you.</para>
<para>Checking files manually gives you better control of the
analysis.</para>
<para>We don't know which approach will give you the best results. It is
recommended that you try both. It is possible that you will get
different results so that to find most bugs you need to use both
approaches.</para>
<para>Later chapters will describe this in more detail.</para>
</section>
<section>
<title>Excluding a file or folder from checking</title>
<para>To exclude a file or folder, there are two options. The first
option is to only provide the paths and files you want to check.</para>
<programlisting>cppcheck src/a src/b</programlisting>
<para>All files under <filename class="directory">src/a</filename> and
<filename class="directory">src/b</filename> are then checked.</para>
<para>The second option is to use <parameter
class="command">-i</parameter>, with it you specify files/paths to
ignore. With this command no files in <filename
class="directory">src/c</filename> are checked:</para>
<programlisting>cppcheck -isrc/c src</programlisting>
</section>
<section>
<title>Severities</title>
<para>The possible severities for messages are:</para>
<variablelist>
<varlistentry>
<term>error</term>
<listitem>
<para>used when bugs are found</para>
</listitem>
</varlistentry>
<varlistentry>
<term>warning</term>
<listitem>
<para>suggestions about defensive programming to prevent
bugs</para>
</listitem>
</varlistentry>
<varlistentry>
<term>style</term>
<listitem>
<para>stylistic issues related to code cleanup (unused functions,
redundant code, constness, and such)</para>
</listitem>
</varlistentry>
<varlistentry>
<term>performance</term>
<listitem>
<para>Suggestions for making the code faster. These suggestions
are only based on common knowledge. It is not certain you'll get
any measurable difference in speed by fixing these
messages.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>portability</term>
<listitem>
<para>portability warnings. 64-bit portability. code might work
different on different compilers. etc.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>information</term>
<listitem>
<para>Configuration problems. The recommendation is to only enable
these during configuration.</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>Enable messages</title>
<para>By default only <parameter class="command">error</parameter>
messages are shown. Through the <parameter
class="command">--enable</parameter> command more checks can be
enabled.</para>
<programlisting># enable warning messages
cppcheck --enable=warning file.c
# enable performance messages
cppcheck --enable=performance file.c
# enable information messages
cppcheck --enable=information file.c
# For historical reasons, --enable=style enables warning, performance,
# portability and style messages. These are all reported as "style" when
# using the old xml format.
cppcheck --enable=style file.c
# enable warning and performance messages
cppcheck --enable=warning,performance file.c
# enable unusedFunction checking. This is not enabled by --enable=style
# because it doesn't work well on libraries.
cppcheck --enable=unusedFunction file.c
# enable all messages
cppcheck --enable=all</programlisting>
<para>Please note that <literal>--enable=unusedFunction</literal> should
only be used when the whole program is scanned. Therefore,
<literal>--enable=all</literal> should also only be used when the whole
program is scanned. The reason is that the unusedFunction checking will
warn if a function is not called. There will be noise if function calls
are not seen.</para>
<section>
<title>Inconclusive checks</title>
<para>By default Cppcheck only writes error messages if it is certain.
With <parameter class="command">--inconclusive</parameter> error
messages will also be written when the analysis is
inconclusive.</para>
<programlisting>cppcheck --inconclusive path</programlisting>
<para>This can of course cause false warnings, it might be reported
that there are bugs even though there are not. Only use this command
if false warnings are acceptable.</para>
</section>
</section>
<section>
<title>Saving results in file</title>
<para>Many times you will want to save the results in a file. You can
use the normal shell redirection for piping error output to a
file.</para>
<programlisting>cppcheck file1.c 2&gt; err.txt</programlisting>
</section>
<section>
<title>Multithreaded checking</title>
<para>The option <literal>-j</literal> is used to specify the number of
threads you want to use. For example, to use 4 threads to check the
files in a folder:</para>
<programlisting>cppcheck -j 4 path</programlisting>
<para>Please note that this will disable unusedFunction checking.</para>
</section>
<section>
<title>Platform</title>
<para>You should use a platform configuration that match your
target.</para>
<para>By default Cppcheck uses native platform configuration that works
well if your code is compiled and executed locally.</para>
<para>Cppcheck has builtin configurations for <literal>unix</literal>
and <literal>windows</literal> targets. You can easily use these with
the <literal>--platform</literal> command line flag.</para>
<para>You can also create your own custom platform configuration in a
xml file. Here is an example:</para>
<programlisting>&lt;?xml version="1"?&gt;
&lt;platform&gt;
&lt;char_bit&gt;8&lt;/char_bit&gt;
&lt;default-sign&gt;signed&lt;/default-sign&gt;
&lt;sizeof&gt;
&lt;short&gt;2&lt;/short&gt;
&lt;int&gt;4&lt;/int&gt;
&lt;long&gt;4&lt;/long&gt;
&lt;long-long&gt;8&lt;/long-long&gt;
&lt;float&gt;4&lt;/float&gt;
&lt;double&gt;8&lt;/double&gt;
&lt;long-double&gt;12&lt;/long-double&gt;
&lt;pointer&gt;4&lt;/pointer&gt;
&lt;size_t&gt;4&lt;/size_t&gt;
&lt;wchar_t&gt;2&lt;/wchar_t&gt;
&lt;/sizeof&gt;
&lt;/platform&gt;</programlisting>
</section>
</chapter>
<chapter>
<title>Project</title>
<para>When you use CMake or Visual Studio you can use
<literal>--project</literal> to analyse your project.</para>
<para>It will give you quick and easy results. There is not much
configuration you need to do. But it is hard to say if this will give you
the best results, it is recommended that you try it and also try to
analyse your source code without <literal>--project</literal> and see
which option works best for you.</para>
<section>
<title>CMake</title>
<para>Cppcheck can understand compile databases. You can generate these
with CMake.</para>
<para>Example:</para>
<programlisting>$ cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON .</programlisting>
<para>The file <literal>compile_commands.json</literal> is created in
the current folder.</para>
<para>Now run Cppcheck like this:</para>
<programlisting>$ cppcheck --project=compile_commands.json</programlisting>
</section>
<section>
<title>Visual Studio</title>
<para>You can run Cppcheck on individual project files (*.vcxproj) or on
a whole solution (*.sln)</para>
<programlisting># run cppcheck on a whole solution
$ cppcheck --project=foobar.sln
# run cppcheck on a individual project
$ cppcheck --project=foobar.vcxproj</programlisting>
<para>Please note that there is also a Visual Studio plugin that allows
you to run cppcheck inside Visual Studio.</para>
</section>
</chapter>
<chapter id="preprocessor-configurations">
<title>Preprocessor settings</title>
<para>If you use <literal>--project</literal> then Cppcheck will use the
preprocessor settings from the project file.</para>
<para>Otherwise you'll probably want to configure the include paths,
defines etc.</para>
<section>
<title>Defines</title>
<para>Here is a file that has 2 configurations (with A defined and
without A):</para>
<programlisting>#ifdef A
x = y;
#else
x = z;
#endif</programlisting>
<para>By default Cppcheck will check all preprocessor configurations
(except those that have #error in them). So the above code will be
analysed both when A is defined and when it is not.</para>
<para>You can use -D to change this. When you use -D, cppcheck will by
default only check the given configuration and nothing else. This is how
compilers work. But you can use <literal>--force</literal> or
<literal>--max-configs</literal> to override the number of
configurations.</para>
<programlisting># check all configurations
cppcheck file.c
# only check the configuration A
cppcheck -DA file.c
# check all configurations when macro A is defined
cppcheck -DA --force file.c</programlisting>
<para>Another useful flag might be -U. It undefines a symbol. Example
usage:</para>
<programlisting>cppcheck -UX file.c</programlisting>
<para>That will mean that X is not defined. Cppcheck will not check what
happens when X is defined.</para>
</section>
<section>
<title>Include paths</title>
<para>To add an include path, use <parameter
class="command">-I</parameter>, followed by the path.</para>
<para>Cppcheck's preprocessor basically handles includes like any other
preprocessor. However, while other preprocessors stop working when they
encounter a missing header, cppcheck will just print an information
message and continues parsing the code.</para>
<para>The purpose of this behaviour is that cppcheck is meant to work
without necessarily seeing the entire code. Actually, it is recommended
to not give all include paths. While it is useful for cppcheck to see
the declaration of a class when checking the implementation of its
members, passing standard library headers is highly discouraged because
it will result in worse results and longer checking time. For such
cases, .cfg files (see below) are the better way to provide information
about the implementation of functions and types to cppcheck.</para>
</section>
</chapter>
<chapter>
<title>XML output</title>
<para>Cppcheck can generate output in <literal>XML</literal> format. There
is an old <literal>XML</literal> format (version 1) and a new
<literal>XML</literal> format (version 2). Please use the new version if
you can.</para>
<para>The old version is kept for backwards compatibility only. It will
not be changed, but it will likely be removed someday. Use
<parameter>--xml</parameter> to enable this format.</para>
<para>The new version fixes a few problems with the old format. The new
format will probably be updated in future versions of cppcheck with new
attributes and elements. A sample command to check a file and output
errors in the new <literal>XML</literal> format:</para>
<programlisting>cppcheck --xml-version=2 file1.cpp</programlisting>
<para>Here is a sample version 2 report:</para>
<programlisting>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;results version="2"&gt;
&lt;cppcheck version="1.66"&gt;
&lt;errors&gt;
&lt;error id="someError" severity="error" msg="short error text"
verbose="long error text" inconclusive="true" cwe="312"&gt;
&lt;location file0="file.c" file="file.h" line="1"/&gt;
&lt;/error&gt;
&lt;/errors&gt;
&lt;/results&gt;</programlisting>
<section>
<title>The &lt;error&gt; element</title>
<para>Each error is reported in a <literal>&lt;error&gt;</literal>
element. Attributes:</para>
<variablelist>
<varlistentry>
<term><sgmltag class="attribute">id</sgmltag></term>
<listitem>
<para>id of error. These are always valid symbolnames.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag class="attribute">severity</sgmltag></term>
<listitem>
<para>either: <literal>error</literal>,
<literal>warning</literal>, <literal>style</literal>,
<literal>performance</literal>, <literal>portability</literal> or
<literal>information</literal></para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag class="attribute">msg</sgmltag></term>
<listitem>
<para>the error message in short format</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag>verbose</sgmltag></term>
<listitem>
<para>the error message in long format.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag>inconclusive</sgmltag></term>
<listitem>
<para>This attribute is only used when the message is
inconclusive.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag>cwe</sgmltag></term>
<listitem>
<para>CWE ID for message. This attribute is only used when the CWE
ID for the message is known.</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>The &lt;location&gt; element</title>
<para>All locations related to an error is listed with
<literal>&lt;location&gt;</literal> elements. The primary location is
listed first.</para>
<para>Attributes:</para>
<variablelist>
<varlistentry>
<term><sgmltag class="attribute">file</sgmltag></term>
<listitem>
<para>filename. Both relative and absolute paths are
possible</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag class="attribute">file0</sgmltag></term>
<listitem>
<para>name of the source file (optional)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag class="attribute">line</sgmltag></term>
<listitem>
<para>a number</para>
</listitem>
</varlistentry>
<varlistentry>
<term><sgmltag>msg</sgmltag></term>
<listitem>
<para>this attribute doesn't exist yet. But in the future we may
add a short message for each location.</para>
</listitem>
</varlistentry>
</variablelist>
</section>
</chapter>
<chapter>
<title>Reformatting the output</title>
<para>If you want to reformat the output so it looks different you can use
templates.</para>
<para>To get Visual Studio compatible output you can use <parameter
class="command">--template=vs</parameter>:</para>
<programlisting>cppcheck --template=vs gui/test.cpp</programlisting>
<para>This output will look like this:</para>
<programlisting>Checking gui/test.cpp...
gui/test.cpp(31): error: Memory leak: b
gui/test.cpp(16): error: Mismatching allocation and deallocation: k</programlisting>
<para>To get gcc compatible output you can use <parameter
class="command">--template=gcc</parameter>:</para>
<programlisting>cppcheck --template=gcc gui/test.cpp</programlisting>
<para>The output will look like this:</para>
<programlisting>Checking gui/test.cpp...
gui/test.cpp:31: error: Memory leak: b
gui/test.cpp:16: error: Mismatching allocation and deallocation: k</programlisting>
<para>You can write your own pattern (for example a comma-separated
format):</para>
<programlisting>cppcheck --template="{file},{line},{severity},{id},{message}" gui/test.cpp</programlisting>
<para>The output will look like this:</para>
<programlisting>Checking gui/test.cpp...
gui/test.cpp,31,error,memleak,Memory leak: b
gui/test.cpp,16,error,mismatchAllocDealloc,Mismatching allocation and deallocation: k</programlisting>
<para>The following format specifiers are supported:</para>
<variablelist>
<varlistentry>
<term>callstack</term>
<listitem>
<para>callstack - if available</para>
</listitem>
</varlistentry>
<varlistentry>
<term>file</term>
<listitem>
<para>filename</para>
</listitem>
</varlistentry>
<varlistentry>
<term>id</term>
<listitem>
<para>message id</para>
</listitem>
</varlistentry>
<varlistentry>
<term>line</term>
<listitem>
<para>line number</para>
</listitem>
</varlistentry>
<varlistentry>
<term>message</term>
<listitem>
<para>verbose message text</para>
</listitem>
</varlistentry>
<varlistentry>
<term>severity</term>
<listitem>
<para>a type/rank of message</para>
</listitem>
</varlistentry>
</variablelist>
<para>The escape sequences \b (backspace), \n (newline), \r (formfeed) and
\t (horizontal tab) are supported.</para>
</chapter>
<chapter>
<title>Suppressions</title>
<para>If you want to filter out certain errors you can suppress
these.</para>
<section>
<title>Suppressing a certain error type</title>
<para>You can suppress certain types of errors. The format for such a
suppression is one of:</para>
<programlisting>[error id]:[filename]:[line]
[error id]:[filename2]
[error id]</programlisting>
<para>The <replaceable>error id</replaceable> is the id that you want to
suppress. The easiest way to get it is to use the <parameter
class="command">--xml</parameter> command line flag. Copy and paste the
<replaceable>id</replaceable> string from the XML output. This may be
<literal>*</literal> to suppress all warnings (for a specified file or
files).</para>
<para>The <replaceable>filename</replaceable> may include the wildcard
characters <literal>*</literal> or <literal>?</literal>, which match any
sequence of characters or any single character respectively. It is
recommended that you use "/" as path separator on all operating
systems.</para>
<section>
<title>Command line suppression</title>
<para>The <parameter class="command">--suppress=</parameter> command
line option is used to specify suppressions on the command line.
Example:</para>
<programlisting>cppcheck --suppress=memleak:src/file1.cpp src/</programlisting>
</section>
<section>
<title>Listing suppressions in a file</title>
<para>You can create a suppressions file. Example:</para>
<programlisting>// suppress memleak and exceptNew errors in the file src/file1.cpp
memleak:src/file1.cpp
exceptNew:src/file1.cpp
// suppress all uninitvar errors in all files
uninitvar</programlisting>
<para>Note that you may add empty lines and comments in the
suppressions file.</para>
<para>You can use the suppressions file like this:</para>
<programlisting>cppcheck --suppressions-list=suppressions.txt src/</programlisting>
</section>
</section>
<section>
<title>Inline suppressions</title>
<para>Suppressions can also be added directly in the code by adding
comments that contain special keywords. Before adding such comments,
consider that the code readability is sacrificed a little.</para>
<para>This code will normally generate an error message:</para>
<programlisting>void f() {
char arr[5];
arr[10] = 0;
}</programlisting>
<para>The output is:</para>
<programlisting># cppcheck test.c
Checking test.c...
[test.c:3]: (error) Array 'arr[5]' index 10 out of bounds</programlisting>
<para>To suppress the error message, a comment can be added:</para>
<programlisting>void f() {
char arr[5];
// cppcheck-suppress arrayIndexOutOfBounds
arr[10] = 0;
}</programlisting>
<para>Now the --inline-suppr flag can be used to suppress the warning.
No error is reported when invoking cppcheck this way:</para>
<programlisting>cppcheck --inline-suppr test.c</programlisting>
</section>
</chapter>
<chapter>
<title>Library configuration</title>
<para>When external libraries are used, such as WinAPI, POSIX, gtk, Qt,
etc, <literal>Cppcheck</literal> doesn't know how the external functions
behave. <literal>Cppcheck</literal> then fails to detect various problems
such as leaks, buffer overflows, possible null pointer dereferences, etc.
But this can be fixed with configuration files.</para>
<para>Cppcheck already contains configurations for several libraries. They
can be loaded as described below. Note that the configuration for the
standard libraries of C and C++, <literal>std.cfg</literal>, is always
loaded by cppcheck. If you create or update a configuration file for a
popular library, we would appreciate if you upload it to us.</para>
<section>
<title>Using your own custom .cfg file</title>
<para>You can create and use your own .cfg files for your projects. Use
<literal>--check-library</literal> and
<literal>--enable=information</literal> to get hints about what you
should configure.</para>
<para>It is recommended that you use the <literal>Library
Editor</literal> in the <literal>Cppcheck GUI</literal> to edit
configuration files. It is available in the <literal>View</literal>
menu. All settings are not documented in this manual.</para>
<para>If you have a question about the <literal>.cfg</literal> file
format it is recommended you ask in the forum
(http://sourceforge.net/p/cppcheck/discussion/).</para>
<para>The command line cppcheck will try to load custom .cfg files from
the working path - execute cppcheck from the path where the .cfg files
are.</para>
<para>The cppcheck GUI will try to load custom .cfg files from the
project file path. The custom .cfg files should be shown in the
<literal>Edit Project File</literal> dialog that you open from the
<literal>File</literal> menu.</para>
</section>
<section>
<title>Memory/resource leaks</title>
<para>Cppcheck has configurable checking for leaks, e.g. you can specify
which functions allocate and free memory or resources and which
functions do not affect the allocation at all.</para>
<section>
<title>alloc and dealloc</title>
<para>Here is an example program:</para>
<para><programlisting>void test()
{
HPEN pen = CreatePen(PS_SOLID, 1, RGB(255,0,0));
}</programlisting></para>
<para>The code example above has a resource leak -
<literal>CreatePen()</literal> is a WinAPI function that creates a
pen. However, Cppcheck doesn't assume that return values from
functions must be freed. There is no error message:</para>
<programlisting># cppcheck pen1.c
Checking pen1.c...</programlisting>
<para>If you provide a configuration file then
<literal>Cppcheck</literal> detects the bug:</para>
<programlisting># cppcheck --library=windows.cfg pen1.c
Checking pen1.c...
[pen1.c:3]: (error) Resource leak: pen</programlisting>
<para>Here is a minimal <literal>windows.cfg</literal> file:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;resource&gt;
&lt;alloc&gt;CreatePen&lt;/alloc&gt;
&lt;dealloc&gt;DeleteObject&lt;/dealloc&gt;
&lt;/resource&gt;
&lt;/def&gt;</programlisting>
<para>The allocation and deallocation functions are organized in
groups. Each group is defined in a <literal>&lt;resource&gt;</literal>
or <literal>&lt;memory&gt;</literal> tag and is identified by its
<literal>&lt;dealloc&gt;</literal> functions. This means, groups with
overlapping <literal>&lt;dealloc&gt;</literal> tags are merged.</para>
</section>
<section>
<title>leak-ignore and use</title>
<para>Often the allocated pointer is passed to functions.
Example:</para>
<programlisting>void test()
{
char *p = malloc(100);
dostuff(p);
}</programlisting>
<para>If Cppcheck doesn't know what <literal>dostuff</literal> does,
without configuration it will assume that <literal>dostuff</literal>
takes care of the memory so there is no memory leak.</para>
<para>To specify that <literal>dostuff</literal> doesn't take care of
the memory in any way, use <literal>leak-ignore</literal> in the
<literal>&lt;function&gt;</literal> tag (see next section):</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="dostuff"&gt;
&lt;leak-ignore/&gt;
&lt;arg nr="1"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>
<para>If instead <literal>dostuff</literal> takes care of the memory
then this can be configured with:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;memory&gt;
&lt;dealloc&gt;free&lt;/dealloc&gt;
&lt;use&gt;dostuff&lt;/use&gt;
&lt;/memory&gt;
&lt;/def&gt;</programlisting>
<para>The <literal>&lt;use&gt;</literal> configuration has no logical
purpose. You will get the same warnings without it. Use it to silence
<literal>--check-library</literal> information messages.</para>
</section>
</section>
<section>
<title>Function behaviour</title>
<para>To specify the behaviour of functions and how they should be used,
<literal>&lt;function&gt;</literal> tags can be used. Functions are
identified by their name, specified in the <literal>name</literal>
attribute and their number of arguments. The name is a comma-separated
list of function names. For functions in namespaces or classes, just
provide their fully qualified name. For example: <literal>&lt;function
name="memcpy,std::memcpy"&gt;</literal>. If you have template functions
then provide their instantiated names <literal>&lt;function
name="dostuff&lt;int&gt;"&gt;</literal>.</para>
<section>
<title>Function arguments</title>
<para>The arguments a function takes can be specified by
<literal>&lt;arg&gt;</literal> tags. Each of them takes the number of
the argument (starting from 1) in the <literal>nr</literal> attribute,
or <literal>nr="any"</literal> for variadic arguments. Optional
arguments can be specified by providing a default value:
<literal>default="value"</literal>. Specifying <literal>-1</literal>
as the argument number is going to apply a check to all arguments of
that function. The specifications for individual arguments override
this setting.</para>
<section>
<title>Not bool</title>
<para>Here is an example program with misplaced comparison:</para>
<programlisting>void test()
{
if (MemCmp(buffer1, buffer2, 1024==0)) {}
}</programlisting>
<para><literal>Cppcheck</literal> assumes that it is fine to pass
boolean values to functions:</para>
<programlisting># cppcheck notbool.c
Checking notbool.c...</programlisting>
<para>If you provide a configuration file then Cppcheck detects the
bug:</para>
<programlisting># cppcheck --library=notbool.cfg notbool.c
Checking notbool.c...
[notbool.c:5]: (error) Invalid MemCmp() argument nr 3. A non-boolean value is required.</programlisting>
<para>Here is the minimal notbool.cfg</para>
<para><programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="MemCmp"&gt;
&lt;arg nr="1"/&gt;
&lt;arg nr="2"/&gt;
&lt;arg nr="3"&gt;
&lt;not-bool/&gt;
&lt;/arg&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting></para>
</section>
<section>
<title>Uninitialized memory</title>
<para>Here is an example program:</para>
<programlisting>void test()
{
char buffer1[1024];
char buffer2[1024];
CopyMemory(buffer1, buffer2, 1024);
}</programlisting>
<para>The bug here is that buffer2 is uninitialized. The second
argument for CopyMemory needs to be initialized. However,
<literal>Cppcheck</literal> assumes that it is fine to pass
uninitialized variables to functions:</para>
<programlisting># cppcheck uninit.c
Checking uninit.c...</programlisting>
<para>If you provide a configuration file then Cppcheck detects the
bug:</para>
<programlisting># cppcheck --library=windows.cfg uninit.c
Checking uninit.c...
[uninit.c:5]: (error) Uninitialized variable: buffer2</programlisting>
<para>Note that this implies for pointers that the memory they point
at has to be initialized, too.</para>
<para>Here is the minimal <literal>windows.cfg</literal>:</para>
<para><programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="CopyMemory"&gt;
&lt;arg nr="1"/&gt;
&lt;arg nr="2"&gt;
&lt;not-uninit/&gt;
&lt;/arg&gt;
&lt;arg nr="3"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting></para>
</section>
<section>
<title>Null pointers</title>
<para>Cppcheck assumes it's ok to pass NULL pointers to functions.
Here is an example program:</para>
<programlisting>void test()
{
CopyMemory(NULL, NULL, 1024);
}</programlisting>
<para>The MSDN documentation is not clear if that is ok or not. But
let's assume it's bad. Cppcheck assumes that it's ok to pass NULL to
functions so no error is reported:</para>
<programlisting># cppcheck null.c
Checking null.c...</programlisting>
<para>If you provide a configuration file then
<literal>Cppcheck</literal> detects the bug:</para>
<programlisting>cppcheck --library=windows.cfg null.c
Checking null.c...
[null.c:3]: (error) Null pointer dereference</programlisting>
<para>Note that this implies <literal>&lt;not-uninit&gt;</literal>
as far as values are concerned. Uninitialized memory might still be
passed do the function.</para>
<para>Here is a minimal <literal>windows.cfg</literal> file:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="CopyMemory"&gt;
&lt;arg nr="1"&gt;
&lt;not-null/&gt;
&lt;/arg&gt;
&lt;arg nr="2"/&gt;
&lt;arg nr="3"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>
</section>
<section>
<title>Format string</title>
<para>You can define that a function takes a format string.
Example:</para>
<programlisting>void test()
{
do_something("%i %i\n", 1024);
}</programlisting>
<para>No error is reported for that:</para>
<programlisting># cppcheck formatstring.c
Checking formatstring.c...</programlisting>
<para>A configuration file can be created that says that the string
is a format string. For instance:</para>
<para><programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="do_something"&gt;
&lt;formatstr type="printf"/&gt;
&lt;arg nr="1"&gt;
&lt;formatstr/&gt;
&lt;/arg&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>Now Cppcheck will report an error:</para>
<programlisting>cppcheck --library=test.cfg formatstring.c
Checking formatstring.c...
[formatstring.c:3]: (error) do_something format string requires 2 parameters but only 1 is given.</programlisting>
<para>The <literal>type</literal> attribute can be either:</para>
<itemizedlist>
<listitem>
<para>printf - format string follows the printf rules</para>
</listitem>
<listitem>
<para>scanf - format string follows the scanf rules</para>
</listitem>
</itemizedlist>
</section>
<section>
<title>Value range</title>
<para>The valid values can be defined. Imagine:</para>
<programlisting>void test()
{
do_something(1024);
}</programlisting>
<para>No error is reported for that:</para>
<programlisting># cppcheck valuerange.c
Checking valuerange.c...</programlisting>
<para>A configuration file can be created that says that 1024 is out
of bounds. For instance:</para>
<para><programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="do_something"&gt;
&lt;arg nr="1"&gt;
&lt;valid&gt;0:1023&lt;/valid&gt;
&lt;/arg&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>Now Cppcheck will report an error:</para>
<programlisting>cppcheck --library=test.cfg range.c
Checking range.c...
[range.c:3]: (error) Invalid do_something() argument nr 1. The value is 1024 but the valid values are '0-1023'.</programlisting>
<para>Some example expressions you can use in the valid
element:</para>
<programlisting>0,3,5 =&gt; only values 0, 3 and 5 are valid
-10:20 =&gt; all values between -10 and 20 are valid
:0 =&gt; all values that are less or equal to 0 are valid
0: =&gt; all values that are greater or equal to 0 are valid
0,2:32 =&gt; the value 0 and all values between 2 and 32 are valid </programlisting>
</section>
<section>
<title>minsize</title>
<para>Some function arguments take a buffer. With minsize you can
configure the min size of the buffer (in bytes, not elements).
Imagine:</para>
<programlisting>void test()
{
char str[5];
do_something(str,"12345");
}</programlisting>
<para>No error is reported for that:</para>
<programlisting># cppcheck minsize.c
Checking minsize.c...</programlisting>
<para>A configuration file can for instance be created that says
that the size of the buffer in argument 1 must be larger than the
strlen of argument 2.For instance:</para>
<para><programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="do_something"&gt;
&lt;arg nr="1"&gt;
&lt;minsize type="strlen" arg="2"/&gt;
&lt;/arg&gt;
&lt;arg nr="2"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>Now Cppcheck will report this error:</para>
<programlisting>cppcheck --library=1.cfg minsize.c
Checking minsize.c...
[minsize.c:4]: (error) Buffer is accessed out of bounds: str
</programlisting>
<para>There are different types of minsizes:</para>
<variablelist>
<varlistentry>
<term>strlen</term>
<listitem>
<para>buffer size must be larger than other arguments string
length. Example: see strcpy configuration in std.cfg</para>
</listitem>
</varlistentry>
<varlistentry>
<term>argvalue</term>
<listitem>
<para>buffer size must be larger than value in other argument.
Example: see memset configuration in std.cfg</para>
</listitem>
</varlistentry>
<varlistentry>
<term>sizeof</term>
<listitem>
<para>buffer size must be larger than other argument buffer
size. Example: see strncpy configuration in std.cfg</para>
</listitem>
</varlistentry>
<varlistentry>
<term>mul</term>
<listitem>
<para>buffer size must be larger than multiplication result
when multiplying values given in two other arguments.
Typically one argument defines the element size and another
element defines the number of elements. Example: see fread
configuration in std.cfg</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section>
<title>strz</title>
<para>This setting is not used by Cppcheck currently. But with this
you can say that an argument must be a zero-terminated
string.</para>
<para><programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="do_something"&gt;
&lt;arg nr="1"&gt;
&lt;strz/&gt;
&lt;/arg&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting></para>
</section>
</section>
<section>
<title>noreturn</title>
<para>Cppcheck doesn't assume that functions always return. Here is an
example code:</para>
<programlisting>void test(int x)
{
int data, buffer[1024];
if (x == 1)
data = 123;
else
ZeroMemory(buffer, sizeof(buffer));
buffer[0] = data; // &lt;- error: data is uninitialized if x is not 1
}</programlisting>
<para>In theory, if <literal>ZeroMemory</literal> terminates the
program then there is no bug. Cppcheck therefore reports no
error:</para>
<programlisting># cppcheck noreturn.c
Checking noreturn.c...</programlisting>
<para>However if you use <literal>--check-library</literal> and
<literal>--enable=information</literal> you'll get this:</para>
<programlisting># cppcheck --check-library --enable=information noreturn.c
Checking noreturn.c...
[noreturn.c:7]: (information) --check-library: Function ZeroMemory() should have &lt;noreturn&gt; configuration
</programlisting>
<para>If a proper <literal>windows.cfg</literal> is provided, the bug
is detected:</para>
<programlisting># cppcheck --library=windows.cfg noreturn.c
Checking noreturn.c...
[noreturn.c:8]: (error) Uninitialized variable: data</programlisting>
<para>Here is a minimal <literal>windows.cfg</literal> file:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="ZeroMemory"&gt;
&lt;noreturn&gt;false&lt;/noreturn&gt;
&lt;arg nr="1"/&gt;
&lt;arg nr="2"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>
</section>
<section>
<title>use-retval</title>
<para>As long as nothing else is specified, cppcheck assumes that
ignoring the return value of a function is ok:</para>
<programlisting>bool test(const char* a, const char* b)
{
strcmp(a, b); // &lt;- bug: The call of strcmp does not have side-effects, but the return value is ignored.
return true;
}</programlisting>
<para>In case <literal>strcmp</literal> has side effects, such as
assigning the result to one of the parameters passed to it, nothing
bad would happen:</para>
<programlisting># cppcheck useretval.c
Checking useretval.c...</programlisting>
<para>If a proper <literal>lib.cfg</literal> is provided, the bug is
detected:</para>
<programlisting># cppcheck --library=lib.cfg --enable=warning useretval.c
Checking useretval.c...
[useretval.c:3]: (warning) Return value of function strcmp() is not used.</programlisting>
<para>Here is a minimal <literal>lib.cfg</literal> file:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="strcmp"&gt;
&lt;use-retval/&gt;
&lt;arg nr="1"/&gt;
&lt;arg nr="2"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>
</section>
<section>
<title>pure and const</title>
<para>These correspond to the GCC function attributes pure and
const.</para>
<para>A pure function has no effects except to return a value, and its
return value depends only on the parameters and global
variables.</para>
<para>A const function has no effects except to return a value, and
its return value depends only on the parameters.</para>
<para>Here is an example code:</para>
<programlisting>void f(int x)
{
if (calculate(x) == 213) {
} else if (calculate(x) == 213) {
// unreachable code
}
}</programlisting>
<para>If <literal>calculate()</literal> is a const function then the
result of <literal>calculate(x)</literal> will be the same in both
conditions, since the same parameter value is used.</para>
<para>Cppcheck normally assumes that the result might be different,
and reports no warning for the code:</para>
<programlisting># cppcheck const.c
Checking const.c...</programlisting>
<para>If a proper <literal>const.cfg</literal> is provided, the
unreachable code is detected:</para>
<programlisting># cppcheck --enable=style --library=const const.c
Checking const.c...
[const.c:7]: (style) Expression is always false because 'else if' condition matches previous condition at line 5.</programlisting>
<para>Here is a minimal <literal>const.cfg</literal> file:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;function name="calculate"&gt;
&lt;const/&gt;
&lt;arg nr="1"/&gt;
&lt;/function&gt;
&lt;/def&gt;</programlisting>
</section>
<section>
<title>Example configuration for strcpy()</title>
<para>The proper configuration for the standard strcpy() function
would be:</para>
<programlisting> &lt;function name="strcpy"&gt;
&lt;leak-ignore/&gt;
&lt;noreturn&gt;false&lt;/noreturn&gt;
&lt;arg nr="1"&gt;
&lt;not-null/&gt;
&lt;/arg&gt;
&lt;arg nr="2"&gt;
&lt;not-null/&gt;
&lt;not-uninit/&gt;
&lt;strz/&gt;
&lt;/arg&gt;
&lt;/function&gt;</programlisting>
<para>The <literal>&lt;leak-ignore/&gt;</literal> tells Cppcheck to
ignore this function call in the leaks checking. Passing allocated
memory to this function won't mean it will be deallocated.</para>
<para>The <literal>&lt;noreturn&gt;</literal> tells Cppcheck if this
function returns or not.</para>
<para>The first argument that the function takes is a pointer. It must
not be a null pointer, therefore <literal>&lt;not-null&gt;</literal>
is used.</para>
<para>The second argument the function takes is a pointer. It must not
be null. And it must point at initialized data. Using
<literal>&lt;not-null&gt;</literal> and
<literal>&lt;not-uninit&gt;</literal> is correct. Moreover it must
point at a zero-terminated string so &lt;strz&gt; is also used.</para>
</section>
</section>
<section>
<title>define</title>
<para>Libraries can be used to define preprocessor macros as well. For
example:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;define name="NULL_VALUE" value="0"/&gt;
&lt;/def&gt;</programlisting>
<para>Each occurrence of "NULL_VALUE" in the code would then be replaced
by "0" at preprocessor stage.</para>
</section>
<section>
<title>podtype</title>
<para>Lots of code relies on typedefs providing platform independent
types. "podtype"-tags can be used to provide necessary information to
cppcheck to support them. Without further information, cppcheck does not
understand the type "uint16_t" in the following example:</para>
<programlisting>void test() {
uint16_t a;
}</programlisting>
<para>No message about variable 'a' being unused is printed:</para>
<programlisting># cppcheck --enable=style unusedvar.cpp
Checking unusedvar.cpp...</programlisting>
<para>If uint16_t is defined in a library as follows, the result
improves:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;podtype name="uint16_t" sign="u" size="2"/&gt;
&lt;/def&gt;</programlisting>
<para>The size of the type is specified in bytes. Possible values for
the "sign" attribute are "s" (signed) and "u" (unsigned). Both
attributes are optional. Using this library, cppcheck prints:</para>
<programlisting># cppcheck --library=lib.cfg --enable=style unusedvar.cpp
Checking unusedvar.cpp...
[unusedvar.cpp:2]: (style) Unused variable: a</programlisting>
</section>
<section>
<title>container</title>
<para>A lot of C++ libraries, among those the STL itself, provide
containers with very similar functionality. Libraries can be used to
tell cppcheck about their behaviour. Each container needs a unique ID.
It can optionally have a startPattern, which must be a valid
Token::Match pattern and an endPattern that is compared to the linked
token of the first token with such a link. The optional attribute
"inherits" takes an ID from a previously defined container.</para>
<para>Inside the &lt;container&gt; tag, functions can be defined inside
of the tags &lt;size&gt;, &lt;access&gt; and &lt;other&gt; (on your
choice). Each of them can specify an action like "resize" and/or the
result it yields, for example "end-iterator".</para>
<para>The following example provides a definition for std::vector, based
on the definition of "stdContainer" (not shown):</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;def&gt;
&lt;container id="stdVector" startPattern="std :: vector &amp;lt;" inherits="stdContainer"&gt;
&lt;size&gt;
&lt;function name="push_back" action="push"/&gt;
&lt;function name="pop_back" action="pop"/&gt;
&lt;/size&gt;
&lt;access indexOperator="array-like"&gt;
&lt;function name="at" yields="at_index"/&gt;
&lt;function name="front" yields="item"/&gt;
&lt;function name="back" yields="item"/&gt;
&lt;/access&gt;
&lt;/container&gt;
&lt;/def&gt;</programlisting>
</section>
</chapter>
<chapter>
<title>Rules</title>
<para>You can define custom rules using regular expressions.</para>
<para>These rules can not perform sophisticated analysis of the code. But
they give you an easy way to check for various simple patterns in the
code.</para>
<para>To get started writing rules, see the related articles here:</para>
<para><ulink
url="http://sourceforge.net/projects/cppcheck/files/Articles/">http://sourceforge.net/projects/cppcheck/files/Articles/</ulink></para>
<para>The file format for rules is:</para>
<programlisting>&lt;?xml version="1.0"?&gt;
&lt;rule&gt;
&lt;tokenlist&gt;LIST&lt;/tokenlist&gt;
&lt;pattern&gt;PATTERN&lt;/pattern&gt;
&lt;message&gt;
&lt;id&gt;ID&lt;/id&gt;
&lt;severity&gt;SEVERITY&lt;/severity&gt;
&lt;summary&gt;SUMMARY&lt;/summary&gt;
&lt;/message&gt;
&lt;/rule&gt;</programlisting>
<para>CDATA can be used to include characters in a pattern that might
interfere with XML:</para>
<programlisting>&lt;![CDATA[some&lt;strange&gt;pattern]]&gt;</programlisting>
<section>
<title>&lt;tokenlist&gt;</title>
<para>The <literal>&lt;tokenlist&gt;</literal> element is optional. With
this element you can control what tokens are checked. The
<literal>LIST</literal> can be either <literal>define</literal>,
<literal>raw</literal>, <literal>normal</literal> or
<literal>simple</literal>.</para>
<variablelist>
<varlistentry>
<term>define</term>
<listitem>
<para>used to check #define preprocessor statements.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>raw</term>
<listitem>
<para>used to check the preprocessor output.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>normal</term>
<listitem>
<para>used to check the <literal>normal</literal> token list.
There are some simplifications.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>simple</term>
<listitem>
<para>used to check the simple token list. All simplifications are
used. Most Cppcheck checks use the simple token list.</para>
</listitem>
</varlistentry>
</variablelist>
<para>If there is no &lt;tokenlist&gt; element then
<literal>simple</literal> is used automatically.</para>
</section>
<section>
<title>&lt;pattern&gt;</title>
<para>The <literal>PATTERN</literal> is the
<literal>PCRE</literal>-compatible regular expression that will be
executed.</para>
</section>
<section>
<title>&lt;id&gt;</title>
<para>The ID specify the user-defined message id.</para>
</section>
<section>
<title>&lt;severity&gt;</title>
<para>The <literal>SEVERITY</literal> must be one of the
<literal>Cppcheck</literal> severities: <literal>information</literal>,
<literal>performance</literal>, <literal>portability</literal>,
<literal>style</literal>, <literal>warning</literal>, or
<literal>error</literal>.</para>
</section>
<section>
<title>&lt;summary&gt;</title>
<para>Optional. The summary for the message. If no summary is given, the
matching tokens is written.</para>
</section>
</chapter>
<chapter>
<title>Cppcheck addons</title>
<para>Cppcheck addons are implemented as standalone scripts or programs.
With Cppcheck addons, you can for instance:</para>
<itemizedlist>
<listitem>
<para>add extra custom checkers that use sophisticated analysis</para>
</listitem>
<listitem>
<para>visualize your code</para>
</listitem>
<listitem>
<para>etc</para>
</listitem>
</itemizedlist>
<section>
<title>Using Cppcheck addons</title>
<para>Currently there are two steps to use an addon:</para>
<orderedlist>
<listitem>
<para>Run Cppcheck to generate dump files</para>
</listitem>
<listitem>
<para>Run the addon on the dump files</para>
</listitem>
</orderedlist>
<para>The <literal>--dump</literal> flag is used to generate dump files.
To generate a dump file for every source file in the foo/ folder:</para>
<programlisting>cppcheck --dump foo/</programlisting>
<para>To run a addon script on all dump files in the foo/ folder:</para>
<programlisting>python addon.py foo/*.dump</programlisting>
<section>
<title>Where to find some Cppcheck addons</title>
<para>There are a few addons that can be downloaded.</para>
<itemizedlist>
<listitem>
<para>Addons provided by the Cppcheck project:
<uri>http://github.com/danmar/cppcheck/blob/master/addons</uri></para>
</listitem>
<listitem>
<para>ublinter, a project that wants to "lint" for "undefined
behaviour": <uri>http://github.com/danmar/ublinter</uri></para>
</listitem>
</itemizedlist>
<para>We would be happy to add a link to your addon here (no matter if
it's commercial or free).</para>
</section>
</section>
<section>
<title>Writing Cppcheck addons</title>
<para>Cppcheck generates dump files in XML format that contains:</para>
<itemizedlist>
<listitem>
<para>Token list</para>
</listitem>
<listitem>
<para>Syntax trees</para>
</listitem>
<listitem>
<para>Symbol database (functions, classes, variables, all scopes,
..)</para>
</listitem>
<listitem>
<para>Known values (value flow analysis)</para>
</listitem>
</itemizedlist>
<para>Cppcheck can't execute addons directly. There is no direct
interface. This means there are not much restrictions:</para>
<itemizedlist>
<listitem>
<para>You can use any licensing you want for your addons</para>
</listitem>
<listitem>
<para>You can use an arbitrary script/programming language to write
addons</para>
</listitem>
<listitem>
<para>The user interface and output is defined by you</para>
</listitem>
<listitem>
<para>You can use addons for other use cases than generating
warnings</para>
</listitem>
</itemizedlist>
<para>For your convenience, Cppcheck provides cppcheckdata.py that you
can use to access Cppcheck data from Python. Using this is
optional.</para>
<section>
<title>Example 1 - print all tokens</title>
<para>Script:</para>
<programlisting>import sys
import cppcheckdata
def printtokens(data):
for token in data.tokenlist:
print(token.str)
for arg in sys.argv[1:]:
printtokens(cppcheckdata.parse(arg))</programlisting>
</section>
<section>
<title>Example 2 - List all functions</title>
<para>Script:</para>
<programlisting>import sys
import cppcheckdata
def printfunctions(data):
for scope in data.scopes:
if scope.type == 'Function':
print(scope.className)
for arg in sys.argv[1:]:
printfunctions(cppcheckdata.parse(arg))</programlisting>
</section>
<section>
<title>Example 3 - List all classes</title>
<para>Script:</para>
<programlisting>import sys
import cppcheckdata
def printclasses(data):
for scope in data.scopes:
if scope.type == 'Class':
print(scope.className)
for arg in sys.argv[1:]:
printfunctions(cppcheckdata.parse(arg))</programlisting>
</section>
</section>
</chapter>
<chapter>
<title>HTML report</title>
<para>You can convert the XML output from cppcheck into a HTML report.
You'll need Python and the pygments module (<ulink
url="http://pygments.org/">http://pygments.org/</ulink>) for this to work.
In the Cppcheck source tree there is a folder <filename
class="directory">htmlreport</filename> that contains a script that
transforms a Cppcheck XML file into HTML output.</para>
<para>This command generates the help screen:</para>
<programlisting>htmlreport/cppcheck-htmlreport -h</programlisting>
<para>The output screen says:</para>
<programlisting>Usage: cppcheck-htmlreport [options]
Options:
-h, --help show this help message and exit
--file=FILE The cppcheck xml output file to read defects from.
Default is reading from stdin.
--report-dir=REPORT_DIR
The directory where the html report content is written.
--source-dir=SOURCE_DIR
Base directory where source code files can be found.</programlisting>
<para>An example usage:</para>
<programlisting>./cppcheck gui/test.cpp --xml 2&gt; err.xml
htmlreport/cppcheck-htmlreport --file=err.xml --report-dir=test1 --source-dir=.</programlisting>
</chapter>
<chapter>
<title>Graphical user interface</title>
<section>
<title>Introduction</title>
<para>A Cppcheck GUI is available.</para>
<para>The main screen is shown immediately when the GUI is
started.</para>
</section>
<section>
<title>Check source code</title>
<para>Use the <guimenu>Check</guimenu> menu.</para>
</section>
<section>
<title>Inspecting results</title>
<para>The results are shown in a list.</para>
<para>You can show/hide certain types of messages through the
<guimenu>View</guimenu> menu.</para>
<para>Results can be saved to an XML file that can later be opened. See
<literal>Save results to file</literal> and <literal>Open
XML</literal>.</para>
</section>
<section>
<title>Settings</title>
<para>The language can be changed at any time by using the
<guimenu>Language</guimenu> menu.</para>
<para>More settings are available in <menuchoice>
<guimenu>Edit</guimenu>
<guimenuitem>Preferences</guimenuitem>
</menuchoice>.</para>
</section>
<section>
<title>Project files</title>
<para>The project files are used to store project specific settings.
These settings are:</para>
<itemizedlist>
<listitem>
<para>include folders</para>
</listitem>
<listitem>
<para>preprocessor defines</para>
</listitem>
</itemizedlist>
<para>As you can read in <link
linkend="preprocessor-configurations">chapter 3</link> in this manual
the default is that Cppcheck checks all configurations. So only provide
preprocessor defines if you want to limit the checking.</para>
</section>
</chapter>
</book>