This is the tool we use within the curl project to scan C source code and check that it adheres to our Source Code Style guide.
checksrc.pl [options] [file1] [file2] ...
-W[file]
skip that file and exclude it from being checked. Helpful
when, for example, one of the files is generated.
-D[dir]
directory name to prepend to filenames when accessing them.
-h
shows the help output, that also lists all recognized warnings
checksrc
does not check and verify the code against the entire style guide.
The script is an effort to detect the most common mistakes and syntax mistakes
that contributors make before they get accustomed to our code style. Heck,
many of us regulars do the mistakes too and this script helps us keep the code
in shape.
checksrc.pl -h
Lists how to use the script and it lists all existing warnings it has and
problems it detects. At the time of this writing, the existing checksrc
warnings are:
ASSIGNWITHINCONDITION
: Assignment within a conditional expression. The
code style mandates the assignment to be done outside of it.
ASTERISKNOSPACE
: A pointer was declared like char* name
instead of the
more appropriate char *name
style. The asterisk should sit next to the
name.
ASTERISKSPACE
: A pointer was declared like char * name
instead of the
more appropriate char *name
style. The asterisk should sit right next to
the name without a space in between.
BADCOMMAND
: There is a bad checksrc
instruction in the code. See the
Ignore certain warnings section below for details.
BANNEDFUNC
: A banned function was used. The functions sprintf, vsprintf,
strcat, strncat, gets are never allowed in curl source code.
BRACEELSE
: '} else' on the same line. The else is supposed to be on the
following line.
BRACEPOS
: wrong position for an open brace ({
).
BRACEWHILE
: more than once space between end brace and while keyword
COMMANOSPACE
: a comma without following space
COPYRIGHT
: the file is missing a copyright statement
CPPCOMMENTS
: //
comment detected, that is not C89 compliant
DOBRACE
: only use one space after do before open brace
EMPTYLINEBRACE
: found empty line before open brace
EQUALSNOSPACE
: no space after =
sign
EQUALSNULL
: comparison with == NULL
used in if/while. We use !var
.
EXCLAMATIONSPACE
: space found after exclamations mark
FOPENMODE
: fopen()
needs a macro for the mode string, use it
INDENTATION
: detected a wrong start column for code. Note that this
warning only checks some specific places and can certainly miss many bad
indentations.
LONGLINE
: A line is longer than 79 columns.
MULTISPACE
: Multiple spaces were found where only one should be used.
NOSPACEEQUALS
: An equals sign was found without preceding space. We prefer
a = 2
and not a=2
.
NOTEQUALSZERO
: check found using != 0
. We use plain if(var)
.
ONELINECONDITION
: do not put the conditional block on the same line as if()
OPENCOMMENT
: File ended with a comment (/*
) still "open".
PARENBRACE
: ){
was used without sufficient space in between.
RETURNNOSPACE
: return
was used without space between the keyword and the
following value.
SEMINOSPACE
: There was no space (or newline) following a semicolon.
SIZEOFNOPAREN
: Found use of sizeof without parentheses. We prefer
sizeof(int)
style.
SNPRINTF
- Found use of snprintf()
. Since we use an internal replacement
with a different return code etc, we prefer msnprintf()
.
SPACEAFTERPAREN
: there was a space after open parenthesis, ( text
.
SPACEBEFORECLOSE
: there was a space before a close parenthesis, text )
.
SPACEBEFORECOMMA
: there was a space before a comma, one , two
.
SPACEBEFOREPAREN
: there was a space before an open parenthesis, if (
,
where one was not expected
SPACESEMICOLON
: there was a space before semicolon, ;
.
TABS
: TAB characters are not allowed
TRAILINGSPACE
: Trailing whitespace on the line
TYPEDEFSTRUCT
: we frown upon (most) typedefed structs
UNUSEDIGNORE
: a checksrc
inlined warning ignore was asked for but not
used, that is an ignore that should be removed or changed to get used.
Some warnings are quite computationally expensive to perform, so they are
turned off by default. To enable these warnings, place a .checksrc
file in
the directory where they should be activated with commands to enable the
warnings you are interested in. The format of the file is to enable one
warning per line like so: enable <EXTENDEDWARNING>
Currently these are the extended warnings which can be enabled:
COPYRIGHTYEAR
: the current changeset has not updated the copyright year in
the source file
STRERROR
: use of banned function strerror()
STDERR
: use of banned variable stderr
Due to the nature of the source code and the flaws of the checksrc
tool,
there is sometimes a need to ignore specific warnings. checksrc
allows a few
different ways to do this.
You can control what to ignore within a specific source file by providing
instructions to checksrc
in the source code itself. See examples below. The
instruction can ask to ignore a specific warning a specific number of times or
you ignore all of them until you mark the end of the ignored section.
Inline ignores are only done for that single specific source code file.
Example
/* !checksrc! disable LONGLINE all */
This ignores the warning for overly long lines until it is re-enabled with:
/* !checksrc! enable LONGLINE */
If the enabling is not performed before the end of the file, it is enabled again automatically for the next file.
You can also opt to ignore just N violations so that if you have a single long line you just cannot shorten and is agreed to be fine anyway:
/* !checksrc! disable LONGLINE 1 */
... and the warning for long lines is enabled again automatically after it has
ignored that single warning. The number 1
can of course be changed to any
other integer number. It can be used to make sure only the exact intended
instances are ignored and nothing extra.
This is a method we have transitioned away from. Use inline ignores as far as possible.
Make a checksrc.skip
file in the directory of the source code with the
false positive, and include the full offending line into this file.