| <!-- | |
| Copyright (C) Daniel Stenberg, <[email protected]>, et al. | |
| SPDX-License-Identifier: curl | |
| --> | |
| # checksrc | |
| 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](CODE_STYLE.md). | |
| ## Usage | |
| checksrc.pl [options] [file1] [file2] ... | |
| ## Command line options | |
| `-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 | |
| ## What does `checksrc` warn for? | |
| `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. | |
| ### Extended warnings | |
| 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` | |
| ## Ignore certain warnings | |
| 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. | |
| ### Inline ignore | |
| 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. | |
| ### Directory wide ignore patterns | |
| 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. | |