General Options

We list here the general options common to all analyses, that are not tied to a specific language or abstract domain.


--help, -help, -h

Display the list of options.

Without a configuration, the list of all options for all known domains and languages is shown. With a configuration, only the options for the enabled domains and language are listed. The -format json option influences the output (useful for front ends).

-list (domains | checks | hooks)

List the domains, checks performed, or hooks available.

If a configuration is specified, only the domains and checks relevant to the configuration are shown. Note that, even if reporting of a specific alarm is disabled by a command-line option (or unless a command-line option is specified), the corresponding check will still be listed with -list checks. This is because checks are associated to domains that are able to report them, and the list depends only on the list of domains, i.e., the chosen configuration.

The -format json option influences the output (useful for front ends).



Show the version of Mopsa.

-config <file>

Path to the configuration file to use for the analysis.

The configuration file specifies the analyzed language, the set of domains used, and their relationships. It is written in a JSON format. Configuration files are stored in the share/mopsa/configs/ directory and organized by language.

-hook <hook>

Activate a hook.

Use -list hooks to list the available hooks. See also a list of useful hooks and their options.

-share-dir <directory>

Specify the path to the directory containing the shared files, including configuration files and stub files.

Configuration files are searched in <directory>/configs/. Stub files are searched in <directory>/stubs/c/ for C and <directory>/stubs/python/ for Python. The mopsa script sets this path to ../share/mopsa relative to the Mopsa binary (mopsa.bin). This default choice is consistent with both using Mopsa after installation and using Mopsa within the source tree without installation. Using -share-dir is mandatory when using the mopsa.bin binary directly. When using wrappers (such as mopsa, mopsa-c, etc.), it can be used to override the default choice.

-cache <int>

(Internal option). Set the size of the cache used during analysis (default: 5).

Mopsa uses a cache internally to avoid redundant computations of post-conditions and evaluations.


(Internal option). Flag to apply cleaners on the current environment only.


These options change how checks and alarms are displayed.


Display the call stacks when reporting alarms in text format.


Also show safe checks when reporting alarms in text format, in addition to failed checks.


-debug <c1>,<c2>,...,<cn>

Enable some debug channels (default: print).

Debug information in Mopsa are organized into channels, which generally correspond to an abstract domain or an OCaml module. Channels can be enabled selectively. Use _ as a wildcard to enable all channels. The print channel (enabled by default if no -debug option is specified) prints the effect of _mopsa_print directives inserted in the C source to show the abstract value of some variables. Other channels are generally only useful for debugging Mopsa.

-engine (automatic | interactive | dap)

Select the interaction mode with the analysis (default: automatic).

By default, the analysis is carried fully automatically, without user intervention, but alternate interaction modes are possible:

  • The interactive mode provides a gdb-like shell to run the analysis step by step, inspect the abstract state, place breakpoints, etc. It is described in more details in this section.

  • The dap mode is a work in progress to support the Debug Adapter Protocol, used notably in Visual Code Studio.



Disable color in text output.

By default, the analyzer uses ANSI codes to show colors, unless a dumb terminal is detected (TERM set to dumb) or this option is used.


Disable warning messages.

-format (text | json)

Select the output format (default: text).

The JSON output is particularly useful for post-processing by a UI or script (e.g. mopsa-diff). This option influences the output of an analysis as well as the output of the -help and -list commands.

-output <file>

Redirect the output to a file.

When redirecting the text output to a file for future processing, the -no-color option can be useful.


Always return a zero code, even if alarms are detected (default: unset).

If this option is not specified, a return code of 1 is used to denote the presence of alarms.


Print the full abstract state at the end of the analysis (default: unset).

The abstract state when main returns is displayed as if the _mopsa_print() primitive was called.