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>Cppcheck 1.46</TITLE
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><BODY
CLASS="book"
BGCOLOR="#FFFFFF"
TEXT="#000000"
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><DIV
CLASS="BOOK"
><A
NAME="AEN1"
></A
><DIV
CLASS="TITLEPAGE"
><H1
CLASS="title"
><A
NAME="AEN2"
>Cppcheck 1.46</A
></H1
><HR></DIV
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
>1. <A
HREF="#AEN5"
>Introduction</A
></DT
><DT
>2. <A
HREF="#AEN19"
>Getting started</A
></DT
><DD
><DL
><DT
>2.1. <A
HREF="#AEN21"
>First test</A
></DT
><DT
>2.2. <A
HREF="#AEN30"
>Checking all files in a folder</A
></DT
><DT
>2.3. <A
HREF="#AEN36"
>Excluding a file or folder from checking</A
></DT
><DT
>2.4. <A
HREF="#AEN44"
>Severities</A
></DT
><DT
>2.5. <A
HREF="#AEN65"
>Enable messages</A
></DT
><DD
><DL
><DT
>2.5.1. <A
HREF="#AEN70"
>Stylistic issues</A
></DT
><DT
>2.5.2. <A
HREF="#AEN84"
>Unused functions</A
></DT
><DT
>2.5.3. <A
HREF="#AEN88"
>Enable all checks</A
></DT
></DL
></DD
><DT
>2.6. <A
HREF="#AEN93"
>Saving results in file</A
></DT
><DT
>2.7. <A
HREF="#AEN97"
>Multithreaded checking</A
></DT
></DL
></DD
><DT
>3. <A
HREF="#AEN101"
>Preprocessor configurations</A
></DT
><DT
>4. <A
HREF="#AEN109"
>XML output</A
></DT
><DT
>5. <A
HREF="#AEN143"
>Reformatting the output</A
></DT
><DT
>6. <A
HREF="#AEN159"
>Suppressions</A
></DT
><DT
>7. <A
HREF="#AEN172"
>Leaks</A
></DT
><DD
><DL
><DT
>7.1. <A
HREF="#AEN175"
>Userdefined allocation/deallocation functions</A
></DT
></DL
></DD
><DT
>8. <A
HREF="#AEN192"
>Exception safety</A
></DT
><DT
>9. <A
HREF="#AEN212"
>Html report</A
></DT
><DT
>10. <A
HREF="#AEN224"
>Graphical user interface</A
></DT
><DD
><DL
><DT
>10.1. <A
HREF="#AEN226"
>Introduction</A
></DT
><DT
>10.2. <A
HREF="#AEN230"
>Check source code</A
></DT
><DT
>10.3. <A
HREF="#AEN234"
>Inspecting results</A
></DT
><DT
>10.4. <A
HREF="#AEN242"
>Settings</A
></DT
><DT
>10.5. <A
HREF="#AEN249"
>Project files</A
></DT
></DL
></DD
></DL
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN5"
></A
>Chapter 1. Introduction</H1
><P
>Cppcheck is an analysis tool for C/C++ code. Unlike C/C++ compilers
    and many other analysis tools, it doesn't detect syntax errors. Cppcheck
    only detects the types of bugs that the compilers normally fail to detect.
    The goal is no false positives.</P
><P
>Supported code and platforms:</P
><P
></P
><UL
><LI
><P
>You can check non-standard code that includes various compiler
        extensions, inline assembly code, etc.</P
></LI
><LI
><P
>Cppcheck should be compilable by any C++ compiler that handles
        the latest C++ standard.</P
></LI
><LI
><P
>Cppcheck should work on any platform that has sufficient cpu and
        memory.</P
></LI
></UL
><P
>Accuracy</P
><P
>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.</P
><P
>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.</P
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN19"
></A
>Chapter 2. Getting started</H1
><DIV
CLASS="section"
><H2
CLASS="section"
><A
NAME="AEN21"
>2.1. First test</A
></H2
><P
>Here is a simple code</P
><PRE
CLASS="programlisting"
>int main()
{
    char a[10];
    a[10] = 0;
    return 0;
}</PRE
><P
>If you save that into <TT
CLASS="filename"
>file1.c</TT
> and
      execute:</P
><PRE
CLASS="programlisting"
>cppcheck file1.c</PRE
><P
>The output from cppcheck will then be:</P
><PRE
CLASS="programlisting"
>Checking file1.c...
[file1.c:4]: (error) Array 'a[10]' index 10 out of bounds</PRE
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN30"
>2.2. Checking all files in a folder</A
></H2
><P
>Normally a program has many sourcefiles. And you want to check
      them all. Cppcheck can check all sourcefiles in a directory:</P
><PRE
CLASS="programlisting"
>cppcheck path</PRE
><P
>If "path" is a folder then cppcheck will check all sourcefiles in
      this folder.</P
><PRE
CLASS="programlisting"
>Checking path/file1.cpp...
1/2 files checked 50% done
Checking path/file2.cpp...
2/2 files checked 100% done</PRE
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN36"
>2.3. Excluding a file or folder from checking</A
></H2
><P
>There is no command to exclude a file or folder from checking. But
      you can exclude a file or folder by being more careful when including
      files and folders in the checking.</P
><P
>Imagine for example that the folder "src" contain the folders "a",
      "b" and "c". To exclude "c" this command can be used:</P
><PRE
CLASS="programlisting"
>cppcheck src/a src/b</PRE
><P
>All files under "src/a" and "src/b" are then checked.</P
><P
>The flag <TT
CLASS="literal"
>--file-list</TT
> might also be
      useful.</P
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN44"
>2.4. Severities</A
></H2
><P
>The possible severities for messages are:</P
><P
></P
><DIV
CLASS="variablelist"
><DL
><DT
>error</DT
><DD
><P
>used when bugs are found</P
></DD
><DT
>warning</DT
><DD
><P
>suggestions about defensive programming to prevent
            bugs</P
></DD
><DT
>style</DT
><DD
><P
>stylistic issues related to code cleanup (unused functions,
            redundant code, constness, and such)</P
></DD
><DT
>performance</DT
><DD
><P
>suggestions for making the code faster</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN65"
>2.5. Enable messages</A
></H2
><P
>By default only <TT
CLASS="literal"
>error</TT
> messages are shown.
      Through the <TT
CLASS="literal"
>--enable</TT
> command more checks can be
      enabled.</P
><DIV
CLASS="section"
><HR><H3
CLASS="section"
><A
NAME="AEN70"
>2.5.1. Stylistic issues</A
></H3
><P
>With <TT
CLASS="literal"
>--enable=style</TT
> you enable most
        <TT
CLASS="literal"
>warning</TT
>, <TT
CLASS="literal"
>style</TT
> and
        <TT
CLASS="literal"
>performance</TT
> messages.</P
><P
>Here is a simple code example:</P
><PRE
CLASS="programlisting"
>void f(int x)
{
    int i;
    if (x == 0)
    {
        i = 0;
    }
}</PRE
><P
>There are no bugs in that code so Cppcheck won't report anything
        by default. To enable the stylistic messages, use the --enable=style
        command:</P
><PRE
CLASS="programlisting"
>cppcheck --enable=style file3.c</PRE
><P
>The output from Cppcheck is now:</P
><P
><PRE
CLASS="programlisting"
>Checking file3.c...
[file3.c:3]: (style) Variable 'i' is assigned a value that is never used
[file3.c:3]: (style) The scope of the variable i can be reduced</PRE
></P
></DIV
><DIV
CLASS="section"
><HR><H3
CLASS="section"
><A
NAME="AEN84"
>2.5.2. Unused functions</A
></H3
><P
>This check will try to find unused functions. It is best to use
        this when the whole program is checked, so that all usages is seen by
        cppcheck.</P
><PRE
CLASS="programlisting"
>cppcheck --enable=unusedFunction path</PRE
></DIV
><DIV
CLASS="section"
><HR><H3
CLASS="section"
><A
NAME="AEN88"
>2.5.3. Enable all checks</A
></H3
><P
>To enable all checks your can use the
        <TT
CLASS="literal"
>--enable=all</TT
> flag:</P
><PRE
CLASS="programlisting"
>cppcheck --enable=all path</PRE
></DIV
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN93"
>2.6. Saving results in file</A
></H2
><P
>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.</P
><PRE
CLASS="programlisting"
>cppcheck file1.c 2&#62; err.txt</PRE
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN97"
>2.7. Multithreaded checking</A
></H2
><P
>To use 4 threads to check the files in a folder:</P
><PRE
CLASS="programlisting"
>cppcheck -j 4 path</PRE
></DIV
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN101"
></A
>Chapter 3. Preprocessor configurations</H1
><P
>By default Cppcheck will check all preprocessor configurations
    (except those that have #error in them). This is the recommended
    behaviour.</P
><P
>But if you want to manually limit the checking you can do so with
    <TT
CLASS="literal"
>-D</TT
>.</P
><P
>Beware that only the macros, which are given here and the macros
    defined in source files and known header files are considered. That
    excludes all the macros defined in some system header files, which are by
    default not examined by cppcheck.</P
><P
>The usage: if you, for example, want to limit the checking so the
    only configuration to check should be "DEBUG=1;__cplusplus" then something
    like this can be used:</P
><PRE
CLASS="programlisting"
>cppcheck -DDEBUG=1 -D__cplusplus path</PRE
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN109"
></A
>Chapter 4. XML output</H1
><P
>Cppcheck can generate the output in XML format.</P
><P
>Use the --xml flag when you execute cppcheck:</P
><PRE
CLASS="programlisting"
>cppcheck --xml file1.cpp</PRE
><P
>The xml format is:</P
><PRE
CLASS="programlisting"
>&#60;?xml version="1.0"?&#62;
&#60;results&#62;
  &#60;error file="file1.cpp" line="123" id="someError"
               severity="error" msg="some error text"/&#62;
&#60;/results&#62;</PRE
><P
>Attributes:</P
><P
></P
><DIV
CLASS="variablelist"
><DL
><DT
>file</DT
><DD
><P
>filename. Both relative and absolute paths are possible</P
></DD
><DT
>line</DT
><DD
><P
>a number</P
></DD
><DT
>id</DT
><DD
><P
>id of error. These are always valid symbolnames.</P
></DD
><DT
>severity</DT
><DD
><P
>either <TT
CLASS="literal"
>error</TT
> or <TT
CLASS="literal"
>style</TT
>.
          <TT
CLASS="literal"
>warning</TT
> and <TT
CLASS="literal"
>performance</TT
> are
          saved as <TT
CLASS="literal"
>style</TT
>.</P
></DD
><DT
>msg</DT
><DD
><P
>the error message</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN143"
></A
>Chapter 5. Reformatting the output</H1
><P
>If you want to reformat the output so it looks different you can use
    templates.</P
><P
>To get Visual Studio compatible output you can use "--template
    vs":</P
><PRE
CLASS="programlisting"
>cppcheck --template vs gui/test.cpp</PRE
><P
>This output will look like this:</P
><PRE
CLASS="programlisting"
>Checking gui/test.cpp...
gui/test.cpp(31): error: Memory leak: b
gui/test.cpp(16): error: Mismatching allocation and deallocation: k</PRE
><P
>To get gcc compatible output you can use "--template gcc":</P
><PRE
CLASS="programlisting"
>cppcheck --template gcc gui/test.cpp</PRE
><P
>The output will look like this:</P
><PRE
CLASS="programlisting"
>Checking gui/test.cpp...
gui/test.cpp:31: error: Memory leak: b
gui/test.cpp:16: error: Mismatching allocation and deallocation: k</PRE
><P
>You can write your own pattern (for example a comma-separated
    format):</P
><PRE
CLASS="programlisting"
>cppcheck --template "{file},{line},{severity},{id},{message}" gui/test.cpp</PRE
><P
>The output will look like this:</P
><PRE
CLASS="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</PRE
><P
></P
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN159"
></A
>Chapter 6. Suppressions</H1
><P
>If you want to filter out certain errors you can suppress these.
    First you need to create a suppressions file. The format is:</P
><PRE
CLASS="programlisting"
>[error id]:[filename]:[line]
[error id]:[filename2]
[error id]</PRE
><P
>The <TT
CLASS="literal"
>error id</TT
> is the id that you want to suppress.
    The easiest way to get it is to use the <TT
CLASS="literal"
>--xml</TT
> command
    line flag. Copy and paste the <TT
CLASS="literal"
>id</TT
> string from the xml
    output.</P
><P
>Here is an example:</P
><PRE
CLASS="programlisting"
>memleak:file1.cpp
exceptNew:file1.cpp
uninitvar</PRE
><P
>You can then use the suppressions file:</P
><PRE
CLASS="programlisting"
>cppcheck --suppressions suppressions.txt src/</PRE
><P
></P
></DIV
>
<DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN192"
></A
>Chapter 7. Exception safety</H1
><P
>Cppcheck has a few checks that ensure that you don't break the basic
    guarantee of exception safety. It doesn't have any checks for the strong
    guarantee yet.</P
><P
>Example:</P
><PRE
CLASS="programlisting"
>Fred::Fred() : a(new int[20]), b(new int[20])
{
}</PRE
><P
>By default cppcheck will not detect any problems in that
    code.</P
><P
>To enable the exception safety checking you can use
    <TT
CLASS="literal"
>--enable</TT
>:</P
><PRE
CLASS="programlisting"
>cppcheck --enable=exceptNew --enable=exceptRealloc fred.cpp</PRE
><P
>The output will be:</P
><PRE
CLASS="programlisting"
>[fred.cpp:3]: (style) Upon exception there is memory leak: a</PRE
><P
>If an exception occurs when <TT
CLASS="literal"
>b</TT
> is allocated,
    <TT
CLASS="literal"
>a</TT
> will leak.</P
><P
>Here is another example:</P
><PRE
CLASS="programlisting"
>int *p;

int a(int sz)
{
    delete [] p;
    if (sz &#60;= 0)
        throw std::runtime_error("size &#60;= 0");
    p = new int[sz];
}</PRE
><P
>Check that with Cppcheck:</P
><PRE
CLASS="programlisting"
>cppcheck --enable=exceptNew --enable=exceptRealloc except2.cpp</PRE
><P
>The output from Cppcheck is:</P
><PRE
CLASS="programlisting"
>[except2.cpp:7]: (error) Throwing exception in invalid state, p points at deallocated memory</PRE
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN212"
></A
>Chapter 8. Html report</H1
><P
>You can convert the xml output from cppcheck into a html report.
    You'll need python and the pygments module
    (<FONT
COLOR="RED"
>http://pygments.org/</FONT
>) for this to work. In the Cppcheck source
    tree there is a folder "htmlreport" that contains a script that transforms
    a Cppcheck xml file into html output.</P
><P
>This command generates the help screen:</P
><P
><PRE
CLASS="programlisting"
>htmlreport/cppcheck-htmlreport -h</PRE
></P
><P
>The output screen says:</P
><P
><PRE
CLASS="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.</PRE
></P
><P
>An example usage:</P
><PRE
CLASS="programlisting"
>./cppcheck gui/test.cpp --xml 2&#62; err.xml
htmlreport/cppcheck-htmlreport --file=err.xml --report-dir=test1 --source-dir=.</PRE
></DIV
><DIV
CLASS="chapter"
><HR><H1
><A
NAME="AEN224"
></A
>Chapter 9. Graphical user interface</H1
><DIV
CLASS="section"
><H2
CLASS="section"
><A
NAME="AEN226"
>9.1. Introduction</A
></H2
><P
>A Cppcheck GUI is available.</P
><P
>The main screen is shown immediately when the GUI is
      started.</P
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN230"
>9.2. Check source code</A
></H2
><P
>Use the <TT
CLASS="literal"
>Check</TT
> menu.</P
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN234"
>9.3. Inspecting results</A
></H2
><P
>The results are shown in a list.</P
><P
>You can show/hide certain types of messages through the
      <TT
CLASS="literal"
>View</TT
> menu.</P
><P
>Results can be saved to an xml file that can later be opened. See
      <TT
CLASS="literal"
>Save results to file</TT
> and <TT
CLASS="literal"
>Open
      XML</TT
>.</P
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN242"
>9.4. Settings</A
></H2
><P
>The language can be changed at any time by using the
      <TT
CLASS="literal"
>Language</TT
> menu.</P
><P
>More settings are available in
      <TT
CLASS="literal"
>Edit</TT
>&#62;<TT
CLASS="literal"
>Preferences</TT
>.</P
></DIV
><DIV
CLASS="section"
><HR><H2
CLASS="section"
><A
NAME="AEN249"
>9.5. Project files</A
></H2
><P
>The project files are used to store project specific settings.
      These settings are:</P
><P
></P
><UL
><LI
><P
>include folders</P
></LI
><LI
><P
>preprocessor defines</P
></LI
></UL
><P
>It isn't recommended to provide the paths to the standard C/C++
      headers - Cppcheck has internal knowledge about ANSI C/C++ and it isn't
      recommended that this known functionality is redefined. But feel free to
      try it.</P
><P
>As you can read in chapter 3 in this manual the default is that
      Cppcheck checks all configurations. So only provide preprocessor defines
      if you want to limit the checking.</P
></DIV
></DIV
></DIV
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>