Troubleshooting

Answers to common questions and problems.

I get many "Include file not found" messages

There are two kinds:

• missingIncludeSystem: a standard or system header, such as <stdio.h> or <vector>, was not found. This is normal. Cppcheck does not need these headers, because it knows the standard library and the libraries you select in the project. Hide the information severity, or suppress the id missingIncludeSystem in the project.
• missingInclude: one of your own headers was not found. Fix this: add the folder of the header to the include paths of the project, or import the project from your build system so that Cppcheck gets the same include paths as the compiler.

Use Analyze > Check configuration (defines, includes) to get a list of the configuration problems of the project.

Cppcheck reports a syntax error or an unknown macro

Cppcheck does not analyze a file it can not parse. A message like There is an unknown macro here somewhere. Configuration is required. means that the code uses a macro that Cppcheck does not know, in a place where the code can not be parsed without knowing what the macro means. For example:

DECLARE_HANDLER(foo)    // what is this?
{
    ...
}

To fix it, do one of these:

• add the include path of the header that defines the macro,
• select the library that the macro belongs to (for example qt for Q_OBJECT and signals, or windows for the Windows API macros),
• give the macro a value in Defines, for example DECLARE_HANDLER(x)=void x(), or in a library configuration file.

If the code is correct and compiles, but Cppcheck still reports a syntax error, please report it as a Cppcheck bug.

The analysis is slow

• Use a build dir. Then unchanged files are not analyzed again.
• Increase the Number of threads in the preferences.
• Use the Reduced or Normal check level instead of Exhaustive.
• Make sure that Force checking all #ifdef configurations is off in the preferences.
• Use undefines to skip configurations you do not need, or import a compile database: then each file is analyzed with one configuration only.
• Do not add system include folders (such as /usr/include) to the include paths.
• Exclude generated code and 3rd party code.
• Use View > Thread Details to find files that take long; see Thread details.

A warning is wrong (false positive)

First check the configuration: missing include paths and missing library configurations are common causes. For example, if your code calls a function that never returns and Cppcheck does not know that, it can report problems in code that is never reached. Configure the function as noreturn in a library configuration (see Library editor).

If the configuration is right, suppress the warning (see Hiding and suppressing warnings) and please report the false positive to the Cppcheck project with a small code example. Use the scratchpad to make the example as small as possible.

A bug that I know of is not found

• Check that the severity of the warning is shown in the severity toolbar, that the quick filter is empty, that no warnings are hidden (View > Show hidden) and that View > Report is Normal.
• Check that the file was analyzed: look in the Analysis Log.
• Check that the code was analyzed with the right configuration. If the code is in an #ifdef block, it may only be analyzed when a macro is defined.
• Select the libraries that the code uses, so that Cppcheck knows how their functions behave.
• Try the Exhaustive check level and enable inconclusive warnings in the preferences.
• Bugs that span several files need a build dir (whole program analysis).

Cppcheck can not find all bugs. If you think the bug should be found, create a small example in the scratchpad and report it to the Cppcheck project.

Checking the library configuration

Select Analyze > Reanalyze and check library. The project is analyzed again, and Cppcheck reports information messages for functions it has no configuration for, for example:

• checkLibraryNoReturn: Cppcheck does not know if the function can return. Configure noreturn for it.
• checkLibraryFunction: the function is not configured at all. If it is a library function, configure it so that Cppcheck can check how it is used.

Write the missing configuration in a .cfg file with the library editor or a text editor, put it in the folder of the project file and select it on the Types and Functions tab of the project.

Addons do not work

• Addons are Python scripts. Install Python, and if it is not in the PATH, set the Python binary in the preferences.
• The project needs a build dir. Without it, the analysis is stopped with the message To check the project using addons, you need a build directory.
• If an addon is shown as (Not found) in the project dialog, the Cppcheck installation is incomplete.

Clang-Tidy is "not found"

Install Clang-Tidy (it is part of LLVM/Clang). If it is not in the PATH, set the Clang path in the preferences to the folder where clang-tidy is.

Double-clicking a warning does nothing

No editor is configured, or no default editor is selected. Add your editor on the Applications tab of the preferences and click Set as default. If the editor does not start, check the executable path and the parameters.

The results are old

When you open a project with a build dir, the results of the last analysis are shown, not a new analysis. Click Reanalyze all files to analyze the current code.

"Failed to load std.cfg"

The GUI can not find its data files. The Cppcheck installation is broken; reinstall Cppcheck. If you built Cppcheck yourself, make sure the cfg folder is installed next to the program, or configure the data folder with the --data-dir command line option.

Where can I get more help?

• The Cppcheck manual: https://cppcheck.sourceforge.io/manual.pdf
• The Cppcheck home page: https://cppcheck.sourceforge.io/
• The bug tracker: https://trac.cppcheck.net/

Previous: Command line options | Back to Contents