| 1 | .TH LINT 1 |
| 2 | .SH NAME |
| 3 | lint \- a C program verifier |
| 4 | .SH SYNOPSIS |
| 5 | .B lint |
| 6 | [ |
| 7 | .B \-abchnpuvx |
| 8 | ] |
| 9 | file ... |
| 10 | .SH DESCRIPTION |
| 11 | .I Lint |
| 12 | attempts to detect features of the C program |
| 13 | .I files |
| 14 | which are |
| 15 | likely to be bugs, or non-portable, or wasteful. |
| 16 | It also checks the type usage of the program more strictly |
| 17 | than the compilers. |
| 18 | Among the things which are currently found are |
| 19 | unreachable statements, |
| 20 | loops not entered at the top, |
| 21 | automatic variables declared and not used, |
| 22 | and logical expressions whose value is constant. |
| 23 | Moreover, the usage of functions is checked to find |
| 24 | functions which return values in some places and not in others, |
| 25 | functions called with varying numbers of arguments, |
| 26 | and functions whose values are not used. |
| 27 | .PP |
| 28 | By default, it is assumed that all the |
| 29 | .I files |
| 30 | are to be loaded together; they are checked for |
| 31 | mutual compatibility. |
| 32 | Function definitions for certain libraries are available to |
| 33 | .IR lint ; |
| 34 | these libraries are referred to by a |
| 35 | conventional name, |
| 36 | such as `-lm', in the style of |
| 37 | .IR ld (1). |
| 38 | .PP |
| 39 | Any number of the options in the following list |
| 40 | may be used. |
| 41 | The |
| 42 | .SM |
| 43 | .BR \-D "\*S," |
| 44 | .SM |
| 45 | .BR \-U "\*S," |
| 46 | and |
| 47 | .SM |
| 48 | .B \-I |
| 49 | options of |
| 50 | .IR cc (1) |
| 51 | are also recognized as separate arguments. |
| 52 | .TP |
| 53 | .B p |
| 54 | Attempt to check portability to the |
| 55 | .I IBM |
| 56 | and |
| 57 | .I GCOS |
| 58 | dialects of C. |
| 59 | .TP |
| 60 | .B h |
| 61 | Apply a number of heuristic tests to attempt to |
| 62 | intuit bugs, improve style, and reduce waste. |
| 63 | .TP |
| 64 | .B b |
| 65 | Report |
| 66 | .I break |
| 67 | statements that cannot be reached. |
| 68 | (This is not the default because, unfortunately, |
| 69 | most |
| 70 | .I lex |
| 71 | and many |
| 72 | .I yacc |
| 73 | outputs produce dozens of such comments.) |
| 74 | .TP |
| 75 | .B v |
| 76 | Suppress complaints about unused arguments in functions. |
| 77 | .TP |
| 78 | .B x |
| 79 | Report variables referred to by extern declarations, |
| 80 | but never used. |
| 81 | .TP |
| 82 | .B a |
| 83 | Report assignments of long values to int variables. |
| 84 | .TP |
| 85 | .B c |
| 86 | Complain about casts which have questionable portability. |
| 87 | .TP |
| 88 | .B u |
| 89 | Do not complain about functions and variables used and not |
| 90 | defined, or defined and not used (this is suitable for running |
| 91 | .I lint |
| 92 | on a subset of files out of a larger program). |
| 93 | .TP |
| 94 | .B n |
| 95 | Do not check compatibility against the standard library. |
| 96 | .PP |
| 97 | .IR Exit (2) |
| 98 | and other functions which do not return |
| 99 | are not understood; this causes various lies. |
| 100 | .PP |
| 101 | Certain conventional comments in the C source |
| 102 | will change the behavior of |
| 103 | .IR lint : |
| 104 | .TP |
| 105 | /*NOTREACHED*/ |
| 106 | at appropriate points |
| 107 | stops comments about unreachable code. |
| 108 | .TP |
| 109 | .RI /*VARARGS n */ |
| 110 | suppresses |
| 111 | the usual checking for variable numbers of arguments |
| 112 | in the following function declaration. |
| 113 | The data types of the first |
| 114 | .I n |
| 115 | arguments are checked; |
| 116 | a missing |
| 117 | .I n |
| 118 | is taken to be 0. |
| 119 | .TP |
| 120 | /*NOSTRICT*/ |
| 121 | shuts off strict type checking in the next expression. |
| 122 | .TP |
| 123 | /*ARGSUSED*/ |
| 124 | turns on the |
| 125 | .B \-v |
| 126 | option for the next function. |
| 127 | .TP |
| 128 | /*LINTLIBRARY*/ |
| 129 | at the beginning of a file shuts off complaints about |
| 130 | unused functions in this file. |
| 131 | .SH FILES |
| 132 | .ta \w'/usr/lib/llib-port 'u |
| 133 | /usr/lib/lint[12] programs |
| 134 | .br |
| 135 | /usr/lib/llib-lc declarations for standard functions |
| 136 | .br |
| 137 | /usr/lib/llib-port declarations for portable functions |
| 138 | .SH SEE ALSO |
| 139 | cc(1) |
| 140 | .br |
| 141 | S. C. Johnson, |
| 142 | .I Lint, a C Program Checker |