Provided by: frama-c-base_20170501+phosphorus+dfsg-2build1_amd64 
NAME
frama-c[.byte] - a static analyzer for C programs
frama-c-gui[.byte] - the graphical interface of frama-c
SYNOPSIS
frama-c [ options ] files
DESCRIPTION
frama-c is a suite of tools dedicated to the analysis of source code written in C. It gathers several
static analysis techniques in a single collaborative framework. This framework can be extended by
additional plugins placed in the $FRAMAC_PLUGIN directory. The command
frama-c --plugins
will provide the full list of the plugins that are currently installed.
frama-c-gui is the graphical user interface of frama-c. It features the same options as the command-line
version.
frama-c.byte and frama-c-gui.byte are the ocaml bytecode versions of the command-line and graphical user
interface respectively.
By default, Frama-C recognizes .c files as C files needing pre-processing and .i files as C files having
been already pre-processed. Some plugins may extend the list of recognized files. Pre-processing can be
customized through the -cpp-command and -cpp-extra-args options.
OPTIONS
Syntax
Options taking an additional parameter can also be written under the form
-option=param
This form is mandatory when param starts with a dash ('-').
Most options that take no parameter have a corresponding
-no-option
option which has the opposite effect.
Help options
-help gives a short usage notice.
-kernel-help
prints the list of options recognized by Frama-C's kernel
-verbose n
Sets verbosity level (default is 1). Setting it to 0 will output less progress messages. This
level can also be set on a per-plugin basis, with option -plugin-verbose n. Verbosity level of
the kernel can be controlled with option -kernel-verbose n.
-debug n
Sets debugging level (default is 0, meaning no debugging messages). This option has the same per-
plugin (and kernel) specializations as -verbose.
-quiet Sets verbosity and debugging level to 0.
Options controlling Frama-C's kernel
-absolute-valid-range <min-max>
considers that all numerical addresses in the range min-max are valid. Bounds are parsed as ocaml
integer constants. By default, all numerical addresses are considered invalid.
-add-path p1[,p2[...,pn]]
adds directories <p1> through <pn> to the list of directories in which plugins are searched.
[-no]-aggressive-merging
merges function definitions modulo renaming. Defaults to no.
[-no]-allow-duplication
allows duplication of small blocks during normalization of tests and loops. Otherwise,
normalization uses labels and gotos. Bigger blocks and blocks with non-trivial control flow are
never duplicated. Defaults to yes.
[-no]-annot
reads ACSL annotations. This is the default. Annotations are pre-processed by default. Use -no-pp-
annot if you don't want to expand macros in annotations.
-big-ints-hex max
integers larger than max are displayed in hexadecimal (by default, all integers are displayed in
decimal)
-check performs integrity checks on the internal AST (for developers only).
[-no]-asm-contracts
generates contracts for assembly code written according to gcc's extended syntax. Defaults to yes.
[-no]-asm-contracts-auto-validate
automatically marks contracts generated from asm as valid. Defaults to no.
-c11 enables (partial) C11 compatibility, e.g. typedef redefinitions. Defaults to no.
[-no]-collapse-call-cast
allows implicit cast between the value returned by a function and the lvalue it is assigned to.
Otherwise, a temporary variable is used and the cast is made explicit. Defaults to yes.
[-no]-constfold
folds all syntactically constant expressions in the code before analyses. Defaults to no.
-const-readonly
variables with const qualifier must be actually constant. Defaults to yes. The opposite option is
-unsafe-writable.
[-no]-continue-annot-error
When analyzing an annotation, the default behavior (the -no version of this option) when a
typechecking error occurs is to reject the source file as is the case for typechecking errors
within the C code. With this option on, the typechecker will only output a warning and discard the
annotation but typechecking will continue (errors in C code are still fatal, though).
-cpp-command cmd
Uses cmd as the command to pre-process C files. Defaults to the CPP environment variable or to
gcc -C -E -I.
if it is not set. In order to preserve ACSL annotations, the preprocessor must keep comments (the
-C option for gcc). %1 and %2 can be used in cmd to denote the original source file and the pre-
processed file respectively.
-cpp-extra-args args
Gives additional arguments to the pre-processor. This is only useful when -preprocess-annot is
set. Pre-processing annotations is done in two separate pre-processing stages. The first one is a
normal pass on the C code which retains macro definitions. These are then used in the second pass
during which annotations are pre-processed. args are used only for the first pass, so that
arguments that should not be used twice (such as additional include directives or macro
definitions) must thus go there instead of -cpp-command.
[-no]-cpp-frama-c-compliant
indicates that the chosen preprocessor complies to some Frama-C requirements, such as accepting
the same set of options as GNU cpp, and accepting architecture-specific options such as -m32/-m64.
Default values depend on the installed preprocessor at configure time. See also -pp-annot.
-custom-annot-char c
uses character c for starting ACSL annotations.
[-no]-autoload-plugins
When on, load all the dynamic plugins found in the search path (see -print-plugin-path for more
information on the default search path). Otherwise, only plugins requested by -load-module will be
loaded. Default behavior is on.
-enums repr
Choose the way the representation of enumerated types is determined. frama-c -enums help gives
the list of available options. Default is gcc-enums
-float-digits n
When outputting floating-point numbers, display n digits. Defaults to 12.
-float-flush-to-zero
Floating point operations flush to zero.
-float-hex
display floats as hexadecimal.
-float-normal
display floats with the standard OCaml routine.
-float-relative
display float intervals as [ lower_bound++width ].
[-no]-force-rl-arg-eval
forces right-to-left evaluation order for arguments of function calls. Otherwise the evaluation
order is left unspecified, as in the C standard. Defaults to no.
[-no]-frama-c-stdlib
adds -I$FRAMAC_SHARE/libc to the options given to the cpp command. If -cpp-frama-c-compliant is
not false, also adds -nostdinc to prevent an inconsistent mix of system and Frama-C header files.
Defaults to yes.
-implicit-function-declaration <action>
warns or aborts when a function is called before it has been declared. <action> can be one of
ignore, warn, or error. Defaults to warn.
-initialized-padding-locals
Implicit initialization of locals sets padding bits to 0. If false, padding bits are left
uninitialized (defaults to yes).
-journal-disable
Do not output a journal of the current session. See -journal-enable.
-journal-enable
On by default, dumps a journal of all the actions performed during the current Frama-C session in
the form of an ocaml script that can be replayed with -load-script. The name of the script can be
set with the -journal-name option.
-journal-name name
Set the name of the journal file (without the .ml extension). Defaults to frama_c_journal.
[-no]-keep-comments
Tries to preserve comments when pretty-printing the source code (defaults to no).
[-no]-keep-switch
When -simplify-cfg is set, keeps switch statements. Defaults to no.
-keep-unused-specified-functions
See -remove-unused-specified-functions
-kernel-log kind:file
copies log messages from the Frama-C's kernel to file. kind specifies which kinds of messages to
be copied (e.g. w for warnings, e for errors, etc.). See -kernel-help for more details. Can also
be set on a per-plugin basis, with option -plugin-log.
[-no]-lib-entry
Indicates that the entry point is called during program execution. This implies in particular that
global variables cannot be assumed to have their initial values. The default is -no-lib-entry: the
entry point is also the starting point of the program and globals have their initial value.
-load file
loads the (previously saved) state contained in file.
-load-module m1[,m2[...,mn]]
loads the ocaml modules <m1> through <mn>. These modules must be .cmxs files for the native code
version of Frama-c and .cmo or.cma files for the bytecode version (see the Dynlink section of the
OCaml manual for more information). All modules which are present in the plugin search paths are
automatically loaded.
-load-script s1[,s2,[...,sn]]
loads the ocaml scripts <s1> through <sn>. The scripts must be .ml files. They must be
compilable relying only on the OCaml standard library and Frama-C's API. If some custom
compilation step is needed, compile them outside of Frama-C and use -load-module instead.
-machdep machine
uses machine as the current machine-dependent configuration (size of the various integer types,
endiandness, ...). The list of currently supported machines is available through -machdep help
option. Default is x86_32
-main f
Sets f as the entry point of the analysis. Defaults to 'main'. By default, it is considered as the
starting point of the program under analysis. Use -lib-entry if f is supposed to be called in the
middle of an execution.
-obfuscate
prints an obfuscated version of the code (where original identifiers are replaced by meaningless
ones) and exits. The correspondence table between original and new symbols is kept at the
beginning of the result.
-ocode file
redirects pretty-printed code to file instead of standard output.
[-no]-orig-name
During the normalization phase, some variables may get renamed when different variables with the
same name can co-exist (e.g. a global variable and a formal parameter). When this option is on, a
message is printed each time this occurs. Defaults to no.
[-no]-pp-annot
pre-processes annotations. This is currently only possible when using gcc (or GNU cpp) pre-
processor. The default is to pre-process annotations when the default pre-processor is identified
as GNU or GNU-like. See also -cpp-frama-c-compliant
[-no]-print
pretty-prints the source code as normalized by CIL (defaults to no).
[-no]-print-libc
expands #include directives in the pretty-printed CIL code for files in the Frama-C standard
library (defaults to no).
-print-libpath
outputs the directory where the Frama-C kernel library is installed.
-print-path
alias of -print-share-path
-print-plugin-path
outputs the directory where Frama-C searches its plugins (can be overridden by the FRAMAC_PLUGIN
variable and the -add-path option)
-print-share-path
outputs the directory where Frama-C stores its data (can be overridden by the FRAMAC_SHARE
variable)
[-no]-remove-exn
transforms throw and try/catch statements into normal C functions. Defaults to no, unless the
input source language has an exception mechanism.
-remove-projects p1,...,pn
removes the given projects p1,...,pn. @all_but_current removes all projects but the current one.
-remove-unused-specified-functions
keeps function prototypes that have an ACSL specification but are not used in the code. This is
the default. Functions having the attribute FRAMAC_BUILTIN are always kept.
-safe-arrays
For multidimensional arrays or arrays that are fields inside structs, assumes that all accesses
must be in bound (set by default). The opposite option is -unsafe-arrays.
-save file
Saves Frama-C's state into file after analyses have taken place.
-session s
sets s as the directory in which session files are searched.
[-no]-set-project-as-default
the current project becomes the default one (and so future -then sequences are applied on it).
Defaults to no.
[-no]-simplify-cfg
removes break, continue and switch statements before analyses. Defaults to no.
[-no]-simplify-trivial-loops
simplifies trivial loops such as do ... while (0) loops. Defaults to yes.
-then allows one to compose analyzes: a first run of Frama-C will occur with the options before -then
and a second run will be done with the options after -then on the current project from the first
run.
-then-last
like -then, but the second group of actions is executed on the last project created by a program
transformer.
-then-on prj
Similar to -then except that the second run is performed in project prj. If no such project
exists, Frama-C exits with an error.
-then-replace
like -then-last, but also removes the previous current project.
-time file
appends user time and date in the given file when Frama-C exits.
-typecheck
forces typechecking of the source files. This option is only relevant if no further analysis is
requested (as typechecking will implicitly occur before the analysis is launched).
-ulevel n
syntactically unroll loops n times before the analysis. This can be quite costly and some plugins
(e.g. the value analysis) provide more efficient ways to perform the same thing. See their
respective manuals for more information. This can also be activated on a per-loop basis via the
loop pragma unroll <m> directive. A negative value for n will inhibit such pragmas.
[-no]-ulevel-force
ignores UNROLL loop pragmas disabling unrolling.
[-no]-unicode
outputs ACSL formulas with utf8 characters. This is the default. When given the -no-unicode
option, Frama-C will use the ASCII version instead. See the ACSL manual for the correspondence.
-unsafe-arrays
see -safe-arrays
[-no]-unspecified-access
checks that read/write accesses occurring in an unspecified order (according to the C standard's
notion of sequence points) are performed on separate locations. With -no-unspecified-access,
assumes that it is always the case (this is the default).
-version
outputs the version string of Frama-C.
-warn-decimal-float <freq>
warns when a floating-point constant cannot be exactly represented (e.g. 0.1). <freq> can be one
of none, once, or all
[-no]-warn-signed-downcast
generates alarms when signed downcasts may exceed the destination range (defaults to no).
[-no]-warn-signed-overflow
generates alarms for signed operations that overflow (defaults to yes).
[-no]-warn-unsigned-downcast
generates alarms when unsigned downcasts may exceed the destination range (defaults to no).
[-no]-warn-unsigned-overflow
generates alarms for unsigned operations that overflow (defaults to no).
Plugin-specific options
For each plugin, the command
frama-c -plugin-help
will give the list of options that are specific to the plugin.
EXIT STATUS
0 Successful execution
1 Invalid user input
2 User interruption (kill or equivalent)
3 Unimplemented feature
4 5 6 Internal error
125 Unknown error
Exit status greater than 2 can be considered as a bug (or a feature request for the case of exit status
3) and may be reported on Frama-C's BTS (see below).
ENVIRONMENT VARIABLES
It is possible to control the places where Frama-C looks for its files through the following variables.
FRAMAC_LIB
The directory where kernel's compiled interfaces are installed.
FRAMAC_PLUGIN
The directory where Frama-C can find standard plugins. If you wish to have plugins in several
places, use -add-path instead.
FRAMAC_SHARE
The directory where Frama-C data (e.g. its version of the standard library) is installed.
SEE ALSO
Frama-C user manual: $FRAMAC_SHARE/manuals/user-manual.pdf
Frama-C homepage: http://frama-c.com
Frama-C BTS: http://bts.frama-c.com
2016-12-02 FRAMA-C(1)