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manual: trim the manual somewhat. The "speeding up Cppcheck" chapter was removed. Addons should not be described in detail in the manual it is better that this is done in the addon.

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# Speeding up Cppcheck
It is possible to speed up Cppcheck analysis in a few different ways.
## Preprocessor configurations
Imagine this source code:
void foo()
{
int x;
#ifdef __GNUC__
x = 0;
#endif
#ifdef _MSC_VER
x = 1;
#endif
return x;
}
By default Cppcheck will try to check all the configurations. There are 3 important configurations here:
- Neither `__GNUC__` nor `_MSC_VER` is defined
- `__GNUC__` is defined
- `_MSC_VER` is defined
When you run Cppcheck, the output will be something like:
$ cppcheck test.c
Checking test.c ...
[test.c:10]: (error) Uninitialized variable: x
Checking test.c: __GNUC__...
Checking test.c: _MSC_VER...
Now if you want you can limit the analysis. You probably know what the target compiler is. If `-D` is supplied and you do not specify `--force` then Cppcheck will only check the configuration you give.
$ cppcheck -D __GNUC__ test.c
Checking test.c ...
Checking test.c: __GNUC__=1...
## Unused templates
If you think Cppcheck is slow and you are using templates, then you should try how it works to remove unused templates.
Imagine this code:
template <class T> struct Foo {
T x = 100;
};
template <class T> struct Bar {
T x = 200 / 0;
};
int main() {
Foo<int> foo;
return 0;
}
Cppcheck says:
$ cppcheck test.cpp
Checking test.cpp ...
[test.cpp:7]: (error) Division by zero.
It complains about division by zero in `Bar` even though `Bar` is not instantiated.
You can use the option `--remove-unused-templates` to remove unused templates from Cppcheck analysis.
Example:
$ cppcheck --remove-unused-templates test.cpp
Checking test.cpp ...
This lost message is in theory not critical, since `Bar` is not instantiated the division by zero should not occur in your real program.
The speedup you get can be remarkable.
## Check headers
TBD
# Addons
Addons are scripts with extra checks. Cppcheck is distributed with a few addons. You can easily write your own custom addon.
Addons are scripts with extra checks. Cppcheck is distributed with a few addons.
If an addon does not need any arguments, you can run it directly on the cppcheck command line. For instance you can run the addon "misc" like this:
## Running Addons
cppcheck --addon=misc somefile.c
Addons are standalone scripts that are executed separately.
If an addon need additional arguments, you can not execute it directly on the command line. Create a json file with the addon configuration:
To manually run an addon:
cppcheck --dump somefile.c
python misc.py somefile.c.dump
To run the same addon through Cppcheck directly:
cppcheck --addon=misc.py somefile.c
Some addons need extra arguments. For example misra.py can be executed manually like this:
cppcheck --dump somefile.c
python misra.py --rule-texts=misra.txt somefile.c.dump
You can configure how you want to execute an addon in a json file, for example put this in misra.json:
{
"script": "misra",
"script": "misra.py",
"args": [ "--rule-texts=misra.txt" ]
}
And then such configuration can be executed on the cppcheck command line:
And then the configuration can be executed on the cppcheck command line:
cppcheck --addon=misra.json somefile.c
## CERT
## Help about an addon
Check CERT coding rules. No configuration is needed.
Example usage:
cppcheck --addon=cert somefile.c
## Findcasts
Will just locate C-style casts in the code. No configuration is needed.
Example usage:
cppcheck --addon=findcasts somefile.c
## Misc
Misc checks. No configuration is needed.
These are checks that we thought would be useful, however it could sometimes warn for coding style that is by intention. For instance it warns about missing comma
between string literals in array initializer.. that could be a mistake but maybe you use string concatenation by intention.
Example usage:
cppcheck --addon=misc somefile.c
## Misra
Check that your code is Misra C 2012 compliant.
To run the Misra addon you need to write a configuration file, because the addon require parameters.
To run this addon you need to have a text file with the misra rule texts. You copy/paste these rule texts from the Misra C 2012 PDF, buy this PDF from <http://www.misra.org.uk> (costs 15-20 pounds)
This is an example misra configuration file:
{
"script": "misra",
"args": [ "--rule-texts=misra.txt" ]
}
The file misra.txt contains the text from "Appendix A Summary of guidelines" in the Misra C 2012 PDF.
Appendix A Summary of guidelines
Rule 1.1
Rule text
Rule 1.2
Rule text
...
Usage:
cppcheck --addon=my-misra-config.json somefile.c
## Naming
Check naming conventions. You specify your naming conventions for variables/functions/etc using regular expressions.
Example configuration (variable names must start with lower case, function names must start with upper case):
{
"script": "naming",
"args": [
"--var=[a-z].*",
"--function=[A-Z].*"
]
}
Usage:
cppcheck --addon=my-naming.json somefile.c
## Namingng
Check naming conventions. You specify the naming conventions using regular expressions in a json file.
Example addon configuration:
{
"script": "namingng",
args: [ "--configfile=ROS_naming.json" ]
}
Usage:
cppcheck --addon=namingng-ros.json somefile.c
## Threadsafety
This will warn if you have local static objects that are not threadsafe. No configuration is needed.
Example usage:
cppcheck --addon=threadsafety somefile.c
## Y2038
Check for the Y2038 bug. No configuration is needed.
Example usage:
cppcheck --addon=y2038 somefile.c
You can read about how to use a Cppcheck addon by looking in the addon. The comments at the top of the file should have a description.
# Library configuration