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-
- <div class="SECT1">
- <h1 class="SECT1"><a name="CODING" id="CODING">4. Coding
- Guidelines</a></h1>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S1" id="S1">4.1. Introduction</a></h2>
-
- <p>This set of standards is designed to make our lives easier. It is
- developed with the simple goal of helping us keep the "new and improved
- <span class="APPLICATION">Privoxy</span>" consistent and reliable. Thus
- making maintenance easier and increasing chances of success of the
- project.</p>
-
- <p>And that of course comes back to us as individuals. If we can
- increase our development and product efficiencies then we can solve
- more of the request for changes/improvements and in general feel good
- about ourselves. ;-></p>
+ <head>
+ <title>
+ Coding Guidelines
+ </title>
+ <meta name="GENERATOR" content=
+ "Modular DocBook HTML Stylesheet Version 1.79">
+ <link rel="HOME" title="Privoxy Developer Manual" href="index.html">
+ <link rel="PREVIOUS" title="Documentation Guidelines" href=
+ "documentation.html">
+ <link rel="NEXT" title="Testing Guidelines" href="testing.html">
+ <link rel="STYLESHEET" type="text/css" href="../p_doc.css">
+ <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
+ </head>
+ <body class="SECT1" bgcolor="#EEEEEE" text="#000000" link="#0000FF" vlink=
+ "#840084" alink="#0000FF">
+ <div class="NAVHEADER">
+ <table summary="Header navigation table" width="100%" border="0"
+ cellpadding="0" cellspacing="0">
+ <tr>
+ <th colspan="3" align="center">
+ Privoxy Developer Manual
+ </th>
+ </tr>
+ <tr>
+ <td width="10%" align="left" valign="bottom">
+ <a href="documentation.html" accesskey="P">Prev</a>
+ </td>
+ <td width="80%" align="center" valign="bottom">
+ </td>
+ <td width="10%" align="right" valign="bottom">
+ <a href="testing.html" accesskey="N">Next</a>
+ </td>
+ </tr>
+ </table>
+ <hr align="LEFT" width="100%">
</div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S2" id="S2">4.2. Using Comments</a></h2>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S3" id="S3">4.2.1. Comment, Comment,
- Comment</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Comment as much as possible without commenting the obvious. For
- example do not comment "variable_a is equal to variable_b". Instead
- explain why variable_a should be equal to the variable_b. Just
- because a person can read code does not mean they will understand why
- or what is being done. A reader may spend a lot more time figuring
- out what is going on when a simple comment or explanation would have
- prevented the extra research. Please help your fellow Privoxy
- developers out!</p>
-
- <p>The comments will also help justify the intent of the code. If the
- comment describes something different than what the code is doing
- then maybe a programming error is occurring.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ <div class="SECT1">
+ <h1 class="SECT1">
+ <a name="CODING">4. Coding Guidelines</a>
+ </h1>
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S1">4.1. Introduction</a>
+ </h2>
+ <p>
+ This set of standards is designed to make our lives easier. It is
+ developed with the simple goal of helping us keep the "new and
+ improved <span class="APPLICATION">Privoxy</span>" consistent and
+ reliable. Thus making maintenance easier and increasing chances of
+ success of the project.
+ </p>
+ <p>
+ And that of course comes back to us as individuals. If we can
+ increase our development and product efficiencies then we can solve
+ more of the request for changes/improvements and in general feel
+ good about ourselves. ;->
+ </p>
+ </div>
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S2">4.2. Using Comments</a>
+ </h2>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S3">4.2.1. Comment, Comment, Comment</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Comment as much as possible without commenting the obvious. For
+ example do not comment "variable_a is equal to variable_b".
+ Instead explain why variable_a should be equal to the variable_b.
+ Just because a person can read code does not mean they will
+ understand why or what is being done. A reader may spend a lot
+ more time figuring out what is going on when a simple comment or
+ explanation would have prevented the extra research. Please help
+ your fellow Privoxy developers out!
+ </p>
+ <p>
+ The comments will also help justify the intent of the code. If
+ the comment describes something different than what the code is
+ doing then maybe a programming error is occurring.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
/* if page size greater than 1k ... */
if (page_length() > 1024)
{
"syntax comment". The second is a comment that does not fit what
is actually being done.
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S4" id="S4">4.2.2. Use blocks for
- comments</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Comments can help or they can clutter. They help when they are
- differentiated from the code they describe. One line comments do not
- offer effective separation between the comment and the code. Block
- identifiers do, by surrounding the code with a clear, definable
- pattern.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S4">4.2.2. Use blocks for comments</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Comments can help or they can clutter. They help when they are
+ differentiated from the code they describe. One line comments do
+ not offer effective separation between the comment and the code.
+ Block identifiers do, by surrounding the code with a clear,
+ definable pattern.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
/*********************************************************************
* This will stand out clearly in your code!
*********************************************************************/
do_something_very_important();
}
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Exception:</i></span></p>
-
- <p>If you are trying to add a small logic comment and do not wish to
- "disrupt" the flow of the code, feel free to use a 1 line comment
- which is NOT on the same line as the code.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S5" id="S5">4.2.3. Keep Comments on their
- own line</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>It goes back to the question of readability. If the comment is on
- the same line as the code it will be harder to read than the comment
- that is on its own line.</p>
-
- <p>There are three exceptions to this rule, which should be violated
- freely and often: during the definition of variables, at the end of
- closing braces, when used to comment parameters.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Exception:</i></span>
+ </p>
+ <p>
+ If you are trying to add a small logic comment and do not wish to
+ "disrupt" the flow of the code, feel free to use a 1 line comment
+ which is NOT on the same line as the code.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S5">4.2.3. Keep Comments on their own line</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ It goes back to the question of readability. If the comment is on
+ the same line as the code it will be harder to read than the
+ comment that is on its own line.
+ </p>
+ <p>
+ There are three exceptions to this rule, which should be violated
+ freely and often: during the definition of variables, at the end
+ of closing braces, when used to comment parameters.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
/*********************************************************************
* This will stand out clearly in your code,
* But the second example won't.
} /* -END- do_something_very_important */
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S6" id="S6">4.2.4. Comment each logical
- step</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Logical steps should be commented to help others follow the intent
- of the written code and comments will make the code more
- readable.</p>
-
- <p>If you have 25 lines of code without a comment, you should
- probably go back into it to see where you forgot to put one.</p>
-
- <p>Most "for", "while", "do", etc... loops _probably_ need a comment.
- After all, these are usually major logic containers.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S7" id="S7">4.2.5. Comment All Functions
- Thoroughly</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>A reader of the code should be able to look at the comments just
- prior to the beginning of a function and discern the reason for its
- existence and the consequences of using it. The reader should not
- have to read through the code to determine if a given function is
- safe for a desired use. The proper information thoroughly presented
- at the introduction of a function not only saves time for subsequent
- maintenance or debugging, it more importantly aids in code reuse by
- allowing a user to determine the safety and applicability of any
- function for the problem at hand. As a result of such benefits, all
- functions should contain the information presented in the addendum
- section of this document.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S8" id="S8">4.2.6. Comment at the end of
- braces if the content is more than one screen length</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Each closing brace should be followed on the same line by a
- comment that describes the origination of the brace if the original
- brace is off of the screen, or otherwise far away from the closing
- brace. This will simplify the debugging, maintenance, and readability
- of the code.</p>
-
- <p>As a suggestion , use the following flags to make the comment and
- its brace more readable:</p>
-
- <p>use following a closing brace: } /* -END- if() or while () or
- etc... */</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S6">4.2.4. Comment each logical step</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Logical steps should be commented to help others follow the
+ intent of the written code and comments will make the code more
+ readable.
+ </p>
+ <p>
+ If you have 25 lines of code without a comment, you should
+ probably go back into it to see where you forgot to put one.
+ </p>
+ <p>
+ Most "for", "while", "do", etc... loops _probably_ need a
+ comment. After all, these are usually major logic containers.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S7">4.2.5. Comment All Functions Thoroughly</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ A reader of the code should be able to look at the comments just
+ prior to the beginning of a function and discern the reason for
+ its existence and the consequences of using it. The reader should
+ not have to read through the code to determine if a given
+ function is safe for a desired use. The proper information
+ thoroughly presented at the introduction of a function not only
+ saves time for subsequent maintenance or debugging, it more
+ importantly aids in code reuse by allowing a user to determine
+ the safety and applicability of any function for the problem at
+ hand. As a result of such benefits, all functions should contain
+ the information presented in the addendum section of this
+ document.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S8">4.2.6. Comment at the end of braces if the content
+ is more than one screen length</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Each closing brace should be followed on the same line by a
+ comment that describes the origination of the brace if the
+ original brace is off of the screen, or otherwise far away from
+ the closing brace. This will simplify the debugging, maintenance,
+ and readability of the code.
+ </p>
+ <p>
+ As a suggestion , use the following flags to make the comment and
+ its brace more readable:
+ </p>
+ <p>
+ use following a closing brace: } /* -END- if() or while () or
+ etc... */
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
if (1 == X)
{
do_something_very_important();
...some long list of commands...
} /* -END- if (1 == X) */
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
+ </div>
</div>
- </div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S9" id="S9">4.3. Naming Conventions</a></h2>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S10" id="S10">4.3.1. Variable
- Names</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Use all lowercase, and separate words via an underscore ('_'). Do
- not start an identifier with an underscore. (ANSI C reserves these
- for use by the compiler and system headers.) Do not use identifiers
- which are reserved in ANSI C++. (E.g. template, class, true, false,
- ...). This is in case we ever decide to port Privoxy to C++.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S9">4.3. Naming Conventions</a>
+ </h2>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S10">4.3.1. Variable Names</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Use all lowercase, and separate words via an underscore ('_'). Do
+ not start an identifier with an underscore. (ANSI C reserves
+ these for use by the compiler and system headers.) Do not use
+ identifiers which are reserved in ANSI C++. (E.g. template,
+ class, true, false, ...). This is in case we ever decide to port
+ Privoxy to C++.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int ms_iis5_hack = 0;
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int msiis5hack = 0; int msIis5Hack = 0;
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S11" id="S11">4.3.2. Function
- Names</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Use all lowercase, and separate words via an underscore ('_'). Do
- not start an identifier with an underscore. (ANSI C reserves these
- for use by the compiler and system headers.) Do not use identifiers
- which are reserved in ANSI C++. (E.g. template, class, true, false,
- ...). This is in case we ever decide to port Privoxy to C++.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S11">4.3.2. Function Names</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Use all lowercase, and separate words via an underscore ('_'). Do
+ not start an identifier with an underscore. (ANSI C reserves
+ these for use by the compiler and system headers.) Do not use
+ identifiers which are reserved in ANSI C++. (E.g. template,
+ class, true, false, ...). This is in case we ever decide to port
+ Privoxy to C++.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int load_some_file(struct client_state *csp)
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int loadsomefile(struct client_state *csp)
int loadSomeFile(struct client_state *csp)
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S12" id="S12">4.3.3. Header file
- prototypes</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Use a descriptive parameter name in the function prototype in
- header files. Use the same parameter name in the header file that you
- use in the c file.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S12">4.3.3. Header file prototypes</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Use a descriptive parameter name in the function prototype in
+ header files. Use the same parameter name in the header file that
+ you use in the c file.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
(.h) extern int load_aclfile(struct client_state *csp);
(.c) int load_aclfile(struct client_state *csp)
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
(.h) extern int load_aclfile(struct client_state *); or
(.h) extern int load_aclfile();
(.c) int load_aclfile(struct client_state *csp)
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S13" id="S13">4.3.4. Enumerations, and
- #defines</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Use all capital letters, with underscores between words. Do not
- start an identifier with an underscore. (ANSI C reserves these for
- use by the compiler and system headers.)</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S13">4.3.4. Enumerations, and #defines</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Use all capital letters, with underscores between words. Do not
+ start an identifier with an underscore. (ANSI C reserves these
+ for use by the compiler and system headers.)
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
(enumeration) : enum Boolean {FALSE, TRUE};
(#define) : #define DEFAULT_SIZE 100;
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> We
- have a standard naming scheme for #defines that toggle a feature in
- the preprocessor: FEATURE_>, where > is a short (preferably 1
- or 2 word) description.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> We
+ have a standard naming scheme for #defines that toggle a feature
+ in the preprocessor: FEATURE_>, where > is a short
+ (preferably 1 or 2 word) description.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#define FEATURE_FORCE 1
#ifdef FEATURE_FORCE
#define FORCE_PREFIX blah
#endif /* def FEATURE_FORCE */
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S14" id="S14">4.3.5. Constants</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Spell common words out entirely (do not remove vowels).</p>
-
- <p>Use only widely-known domain acronyms and abbreviations.
- Capitalize all letters of an acronym.</p>
-
- <p>Use underscore (_) to separate adjacent acronyms and
- abbreviations. Never terminate a name with an underscore.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S14">4.3.5. Constants</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Spell common words out entirely (do not remove vowels).
+ </p>
+ <p>
+ Use only widely-known domain acronyms and abbreviations.
+ Capitalize all letters of an acronym.
+ </p>
+ <p>
+ Use underscore (_) to separate adjacent acronyms and
+ abbreviations. Never terminate a name with an underscore.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#define USE_IMAGE_LIST 1
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#define USE_IMG_LST 1 or
#define _USE_IMAGE_LIST 1 or
#define USE_IMAGE_LIST_ 1 or
#define use_image_list 1 or
#define UseImageList 1
</pre>
- </td>
- </tr>
- </table>
+ </td>
+ </tr>
+ </table>
+ </div>
</div>
- </div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S15" id="S15">4.4. Using Space</a></h2>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S16" id="S16">4.4.1. Put braces on a line
- by themselves.</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>The brace needs to be on a line all by itself, not at the end of
- the statement. Curly braces should line up with the construct that
- they're associated with. This practice makes it easier to identify
- the opening and closing braces for a block.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S15">4.4. Using Space</a>
+ </h2>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S16">4.4.1. Put braces on a line by themselves.</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ The brace needs to be on a line all by itself, not at the end of
+ the statement. Curly braces should line up with the construct
+ that they're associated with. This practice makes it easier to
+ identify the opening and closing braces for a block.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
if (this == that)
{
...
}
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <p>if (this == that) { ... }</p>
-
- <p>or</p>
-
- <p>if (this == that) { ... }</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> In the
- special case that the if-statement is inside a loop, and it is
- trivial, i.e. it tests for a condition that is obvious from the
- purpose of the block, one-liners as above may optically preserve the
- loop structure and make it easier to read.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span>
- developer-discretion.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example
- exception:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <p>
+ if (this == that) { ... }
+ </p>
+ <p>
+ or
+ </p>
+ <p>
+ if (this == that) { ... }
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> In
+ the special case that the if-statement is inside a loop, and it
+ is trivial, i.e. it tests for a condition that is obvious from
+ the purpose of the block, one-liners as above may optically
+ preserve the loop structure and make it easier to read.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span>
+ developer-discretion.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example
+ exception:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
while (more lines are read)
{
/* Please document what is/is not a comment line here */
do_something(line);
}
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S17" id="S17">4.4.2. ALL control
- statements should have a block</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Using braces to make a block will make your code more readable and
- less prone to error. All control statements should have a block
- defined.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S17">4.4.2. ALL control statements should have a
+ block</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Using braces to make a block will make your code more readable
+ and less prone to error. All control statements should have a
+ block defined.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
if (this == that)
{
do_something();
do_something_else();
}
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <p>if (this == that) do_something(); do_something_else();</p>
-
- <p>or</p>
-
- <p>if (this == that) do_something();</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> The
- first example in "Instead of" will execute in a manner other than
- that which the developer desired (per indentation). Using code braces
- would have prevented this "feature". The "explanation" and
- "exception" from the point above also applies.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S18" id="S18">4.4.3. Do not
- belabor/blow-up boolean expressions</a></h3>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <p>
+ if (this == that) do_something(); do_something_else();
+ </p>
+ <p>
+ or
+ </p>
+ <p>
+ if (this == that) do_something();
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> The
+ first example in "Instead of" will execute in a manner other than
+ that which the developer desired (per indentation). Using code
+ braces would have prevented this "feature". The "explanation" and
+ "exception" from the point above also applies.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S18">4.4.3. Do not belabor/blow-up boolean
+ expressions</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
structure->flag = (condition);
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <p>if (condition) { structure->flag = 1; } else {
- structure->flag = 0; }</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> The
- former is readable and concise. The later is wordy and inefficient.
- Please assume that any developer new to the project has at least a
- "good" knowledge of C/C++. (Hope I do not offend by that last comment
- ... 8-)</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S19" id="S19">4.4.4. Use white space
- freely because it is free</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Make it readable. The notable exception to using white space
- freely is listed in the next guideline.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <p>
+ if (condition) { structure->flag = 1; } else {
+ structure->flag = 0; }
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> The
+ former is readable and concise. The later is wordy and
+ inefficient. Please assume that any developer new to the project
+ has at least a "good" knowledge of C/C++. (Hope I do not offend
+ by that last comment ... 8-)
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S19">4.4.4. Use white space freely because it is
+ free</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Make it readable. The notable exception to using white space
+ freely is listed in the next guideline.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int first_value = 0;
int some_value = 0;
int another_value = 0;
int this_variable = 0;
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S20" id="S20">4.4.5. Don't use white space
- around structure operators</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>- structure pointer operator ( "->" ) - member operator ( "." )
- - functions and parentheses</p>
-
- <p>It is a general coding practice to put pointers, references, and
- function parentheses next to names. With spaces, the connection
- between the object and variable/function name is not as clear.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S20">4.4.5. Don't use white space around structure
+ operators</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ - structure pointer operator ( "->" ) - member operator ( "."
+ ) - functions and parentheses
+ </p>
+ <p>
+ It is a general coding practice to put pointers, references, and
+ function parentheses next to names. With spaces, the connection
+ between the object and variable/function name is not as clear.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
a_struct->a_member;
a_struct.a_member;
function_name();
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
- a_struct -> a_member; a_struct . a_member; function_name ();</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S21" id="S21">4.4.6. Make the last brace
- of a function stand out</a></h3>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ a_struct -> a_member; a_struct . a_member; function_name ();
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S21">4.4.6. Make the last brace of a function stand
+ out</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int function1( ... )
{
...code...
{
} /* -END- function2 */
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <p>int function1( ... ) { ...code... return(ret_code); } int
- function2( ... ) { }</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> Use 1
- blank line before the closing brace and 2 lines afterward. This makes
- the end of function standout to the most casual viewer. Although
- function comments help separate functions, this is still a good
- coding practice. In fact, I follow these rules when using blocks in
- "for", "while", "do" loops, and long if {} statements too. After all
- whitespace is free!</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span>
- developer-discretion on the number of blank lines. Enforced is the
- end of function comments.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S22" id="S22">4.4.7. Use 3 character
- indentions</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>If some use 8 character TABs and some use 3 character TABs, the
- code can look *very* ragged. So use 3 character indentions only. If
- you like to use TABs, pass your code through a filter such as "expand
- -t3" before checking in your code.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <p>
+ int function1( ... ) { ...code... return(ret_code); } int
+ function2( ... ) { }
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> Use 1
+ blank line before the closing brace and 2 lines afterward. This
+ makes the end of function standout to the most casual viewer.
+ Although function comments help separate functions, this is still
+ a good coding practice. In fact, I follow these rules when using
+ blocks in "for", "while", "do" loops, and long if {} statements
+ too. After all whitespace is free!
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span>
+ developer-discretion on the number of blank lines. Enforced is
+ the end of function comments.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S22">4.4.7. Use 3 character indentions</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ If some use 8 character TABs and some use 3 character TABs, the
+ code can look *very* ragged. So use 3 character indentions only.
+ If you like to use TABs, pass your code through a filter such as
+ "expand -t3" before checking in your code.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
static const char * const url_code_map[256] =
{
NULL, ...
}
return NEVER_GETS_HERE;
-
-}
-</pre>
- </td>
- </tr>
- </table>
- </div>
- </div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S23" id="S23">4.5. Initializing</a></h2>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S24" id="S24">4.5.1. Initialize all
- variables</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Do not assume that the variables declared will not be used until
- after they have been assigned a value somewhere else in the code.
- Remove the chance of accidentally using an unassigned variable.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
-short a_short = 0;
-float a_float = 0;
-struct *ptr = NULL;
-</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> It is
- much easier to debug a SIGSEGV if the message says you are trying to
- access memory address 00000000 and not 129FA012; or array_ptr[20]
- causes a SIGSEV vs. array_ptr[0].</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span>
- developer-discretion if and only if the variable is assigned a value
- "shortly after" declaration.</p>
- </div>
- </div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S25" id="S25">4.6. Functions</a></h2>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S26" id="S26">4.6.1. Name functions that
- return a boolean as a question.</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Value should be phrased as a question that would logically be
- answered as a true or false statement</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+
+}
+</pre>
+ </td>
+ </tr>
+ </table>
+ </div>
+ </div>
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S23">4.5. Initializing</a>
+ </h2>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S24">4.5.1. Initialize all variables</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Do not assume that the variables declared will not be used until
+ after they have been assigned a value somewhere else in the code.
+ Remove the chance of accidentally using an unassigned variable.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
+short a_short = 0;
+float a_float = 0;
+struct *ptr = NULL;
+</pre>
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> It is
+ much easier to debug a SIGSEGV if the message says you are trying
+ to access memory address 00000000 and not 129FA012; or
+ array_ptr[20] causes a SIGSEV vs. array_ptr[0].
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span>
+ developer-discretion if and only if the variable is assigned a
+ value "shortly after" declaration.
+ </p>
+ </div>
+ </div>
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S25">4.6. Functions</a>
+ </h2>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S26">4.6.1. Name functions that return a boolean as a
+ question.</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Value should be phrased as a question that would logically be
+ answered as a true or false statement
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
should_we_block_this();
contains_an_image();
is_web_page_blank();
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S27" id="S27">4.6.2. Always specify a
- return type for a function.</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>The default return for a function is an int. To avoid ambiguity,
- create a return for a function when the return has a purpose, and
- create a void return type if the function does not need to return
- anything.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S28" id="S28">4.6.3. Minimize function
- calls when iterating by using variables</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>It is easy to write the following code, and a clear argument can
- be made that the code is easy to understand:</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S27">4.6.2. Always specify a return type for a
+ function.</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ The default return for a function is an int. To avoid ambiguity,
+ create a return for a function when the return has a purpose, and
+ create a void return type if the function does not need to return
+ anything.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S28">4.6.3. Minimize function calls when iterating by
+ using variables</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ It is easy to write the following code, and a clear argument can
+ be made that the code is easy to understand:
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
for (size_t cnt = 0; cnt < block_list_length(); cnt++)
{
....
}
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span>
- Unfortunately, this makes a function call for each and every
- iteration. This increases the overhead in the program, because the
- compiler has to look up the function each time, call it, and return a
- value. Depending on what occurs in the block_list_length() call, it
- might even be creating and destroying structures with each iteration,
- even though in each case it is comparing "cnt" to the same value,
- over and over. Remember too - even a call to block_list_length() is a
- function call, with the same overhead.</p>
-
- <p>Instead of using a function call during the iterations, assign the
- value to a variable, and evaluate using the variable.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span>
+ Unfortunately, this makes a function call for each and every
+ iteration. This increases the overhead in the program, because
+ the compiler has to look up the function each time, call it, and
+ return a value. Depending on what occurs in the
+ block_list_length() call, it might even be creating and
+ destroying structures with each iteration, even though in each
+ case it is comparing "cnt" to the same value, over and over.
+ Remember too - even a call to block_list_length() is a function
+ call, with the same overhead.
+ </p>
+ <p>
+ Instead of using a function call during the iterations, assign
+ the value to a variable, and evaluate using the variable.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
size_t len = block_list_length();
for (size_t cnt = 0; cnt < len; cnt++)
....
}
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Exceptions:</i></span>
- if the value of block_list_length() *may* change or could
- *potentially* change, then you must code the function call in the
- for/while loop.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S29" id="S29">4.6.4. Pass and Return by
- Const Reference</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>This allows a developer to define a const pointer and call your
- function. If your function does not have the const keyword, we may
- not be able to use your function. Consider strcmp, if it were defined
- as: extern int strcmp(char *s1, char *s2);</p>
-
- <p>I could then not use it to compare argv's in main: int main(int
- argc, const char *argv[]) { strcmp(argv[0], "privoxy"); }</p>
-
- <p>Both these pointers are *const*! If the c runtime library
- maintainers do it, we should too.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S30" id="S30">4.6.5. Pass and Return by
- Value</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Most structures cannot fit onto a normal stack entry (i.e. they
- are not 4 bytes or less). Aka, a function declaration like: int
- load_aclfile(struct client_state csp)</p>
-
- <p>would not work. So, to be consistent, we should declare all
- prototypes with "pass by value": int load_aclfile(struct client_state
- *csp)</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S31" id="S31">4.6.6. Names of include
- files</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Your include statements should contain the file name without a
- path. The path should be listed in the Makefile, using -I as
- processor directive to search the indicated paths. An exception to
- this would be for some proprietary software that utilizes a partial
- path to distinguish their header files from system or other header
- files.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Exceptions:</i></span>
+ if the value of block_list_length() *may* change or could
+ *potentially* change, then you must code the function call in the
+ for/while loop.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S29">4.6.4. Pass and Return by Const Reference</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ This allows a developer to define a const pointer and call your
+ function. If your function does not have the const keyword, we
+ may not be able to use your function. Consider strcmp, if it were
+ defined as: extern int strcmp(char *s1, char *s2);
+ </p>
+ <p>
+ I could then not use it to compare argv's in main: int main(int
+ argc, const char *argv[]) { strcmp(argv[0], "privoxy"); }
+ </p>
+ <p>
+ Both these pointers are *const*! If the c runtime library
+ maintainers do it, we should too.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S30">4.6.5. Pass and Return by Value</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Most structures cannot fit onto a normal stack entry (i.e. they
+ are not 4 bytes or less). Aka, a function declaration like: int
+ load_aclfile(struct client_state csp)
+ </p>
+ <p>
+ would not work. So, to be consistent, we should declare all
+ prototypes with "pass by value": int load_aclfile(struct
+ client_state *csp)
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S31">4.6.6. Names of include files</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Your include statements should contain the file name without a
+ path. The path should be listed in the Makefile, using -I as
+ processor directive to search the indicated paths. An exception
+ to this would be for some proprietary software that utilizes a
+ partial path to distinguish their header files from system or
+ other header files.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#include <iostream.h> /* This is not a local include */
#include "config.h" /* This IS a local include */
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Exception:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Exception:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
/* This is not a local include, but requires a path element. */
#include <sys/fileName.h>
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span>
- Please! do not add "-I." to the Makefile without a _very_ good
- reason. This duplicates the #include "file.h" behavior.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S32" id="S32">4.6.7. Provide multiple
- inclusion protection</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Prevents compiler and linker errors resulting from redefinition of
- items.</p>
-
- <p>Wrap each header file with the following syntax to prevent
- multiple inclusions of the file. Of course, replace PROJECT_H with
- your file name, with "." Changed to "_", and make it uppercase.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span>
+ Please! do not add "-I." to the Makefile without a _very_ good
+ reason. This duplicates the #include "file.h" behavior.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S32">4.6.7. Provide multiple inclusion protection</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Prevents compiler and linker errors resulting from redefinition
+ of items.
+ </p>
+ <p>
+ Wrap each header file with the following syntax to prevent
+ multiple inclusions of the file. Of course, replace PROJECT_H
+ with your file name, with "." Changed to "_", and make it
+ uppercase.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#ifndef PROJECT_H_INCLUDED
#define PROJECT_H_INCLUDED
...
#endif /* ndef PROJECT_H_INCLUDED */
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S33" id="S33">4.6.8. Use `extern "C"` when
- appropriate</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>If our headers are included from C++, they must declare our
- functions as `extern "C"`. This has no cost in C, but increases the
- potential re-usability of our code.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S33">4.6.8. Use `extern "C"` when appropriate</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ If our headers are included from C++, they must declare our
+ functions as `extern "C"`. This has no cost in C, but increases
+ the potential re-usability of our code.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#ifdef __cplusplus
extern "C"
{
}
#endif /* def __cplusplus */
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S34" id="S34">4.6.9. Where Possible, Use
- Forward Struct Declaration Instead of Includes</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Useful in headers that include pointers to other struct's.
- Modifications to excess header files may cause needless compiles.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S34">4.6.9. Where Possible, Use Forward Struct
+ Declaration Instead of Includes</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Useful in headers that include pointers to other struct's.
+ Modifications to excess header files may cause needless compiles.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
/*********************************************************************
* We're avoiding an include statement here!
*********************************************************************/
struct file_list;
extern file_list *xyz;
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> If you
- declare "file_list xyz;" (without the pointer), then including the
- proper header file is necessary. If you only want to prototype a
- pointer, however, the header file is unnecessary.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span> Use
- with discretion.</p>
- </div>
- </div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S35" id="S35">4.7. General Coding
- Practices</a></h2>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S36" id="S36">4.7.1. Turn on
- warnings</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation</i></span></p>
-
- <p>Compiler warnings are meant to help you find bugs. You should turn
- on as many as possible. With GCC, the switch is "-Wall". Try and fix
- as many warnings as possible.</p>
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> If
+ you declare "file_list xyz;" (without the pointer), then
+ including the proper header file is necessary. If you only want
+ to prototype a pointer, however, the header file is unnecessary.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span> Use
+ with discretion.
+ </p>
+ </div>
</div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S37" id="S37">4.7.2. Provide a default
- case for all switch statements</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>What you think is guaranteed is never really guaranteed. The value
- that you don't think you need to check is the one that someday will
- be passed. So, to protect yourself from the unknown, always have a
- default step in a switch statement.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S35">4.7. General Coding Practices</a>
+ </h2>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S36">4.7.1. Turn on warnings</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Explanation</i></span>
+ </p>
+ <p>
+ Compiler warnings are meant to help you find bugs. You should
+ turn on as many as possible. With GCC, the switch is "-Wall". Try
+ and fix as many warnings as possible.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S37">4.7.2. Provide a default case for all switch
+ statements</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ What you think is guaranteed is never really guaranteed. The
+ value that you don't think you need to check is the one that
+ someday will be passed. So, to protect yourself from the unknown,
+ always have a default step in a switch statement.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
switch (hash_string(cmd))
{
case hash_actions_file:
} /* end switch (hash_string(cmd)) */
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> If you
- already have a default condition, you are obviously exempt from this
- point. Of note, most of the WIN32 code calls `DefWindowProc' after
- the switch statement. This API call *should* be included in a default
- statement.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Another
- Note:</i></span> This is not so much a readability issue as a robust
- programming issue. The "anomaly code goes here" may be no more than a
- print to the STDERR stream (as in load_config). Or it may really be
- an abort condition.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span>
- Programmer discretion is advised.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S38" id="S38">4.7.3. Try to avoid falling
- through cases in a switch statement.</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>In general, you will want to have a 'break' statement within each
- 'case' of a switch statement. This allows for the code to be more
- readable and understandable, and furthermore can prevent unwanted
- surprises if someone else later gets creative and moves the code
- around.</p>
-
- <p>The language allows you to plan the fall through from one case
- statement to another simply by omitting the break statement within
- the case statement. This feature does have benefits, but should only
- be used in rare cases. In general, use a break statement for each
- case statement.</p>
-
- <p>If you choose to allow fall through, you should comment both the
- fact of the fall through and reason why you felt it was
- necessary.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S40" id="S40">4.7.4. Don't mix size_t and
- other types</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>The type of size_t varies across platforms. Do not make
- assumptions about whether it is signed or unsigned, or about how long
- it is. Do not compare a size_t against another variable of a
- different type (or even against a constant) without casting one of
- the values.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S41" id="S41">4.7.5. Declare each variable
- and struct on its own line.</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>It can be tempting to declare a series of variables all on one
- line. Don't.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> If
+ you already have a default condition, you are obviously exempt
+ from this point. Of note, most of the WIN32 code calls
+ `DefWindowProc' after the switch statement. This API call
+ *should* be included in a default statement.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Another
+ Note:</i></span> This is not so much a readability issue as a
+ robust programming issue. The "anomaly code goes here" may be no
+ more than a print to the STDERR stream (as in load_config). Or it
+ may really be an abort condition.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span>
+ Programmer discretion is advised.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S38">4.7.3. Try to avoid falling through cases in a
+ switch statement.</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ In general, you will want to have a 'break' statement within each
+ 'case' of a switch statement. This allows for the code to be more
+ readable and understandable, and furthermore can prevent unwanted
+ surprises if someone else later gets creative and moves the code
+ around.
+ </p>
+ <p>
+ The language allows you to plan the fall through from one case
+ statement to another simply by omitting the break statement
+ within the case statement. This feature does have benefits, but
+ should only be used in rare cases. In general, use a break
+ statement for each case statement.
+ </p>
+ <p>
+ If you choose to allow fall through, you should comment both the
+ fact of the fall through and reason why you felt it was
+ necessary.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S40">4.7.4. Don't mix size_t and other types</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ The type of size_t varies across platforms. Do not make
+ assumptions about whether it is signed or unsigned, or about how
+ long it is. Do not compare a size_t against another variable of a
+ different type (or even against a constant) without casting one
+ of the values.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S41">4.7.5. Declare each variable and struct on its own
+ line.</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ It can be tempting to declare a series of variables all on one
+ line. Don't.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
long a = 0;
long b = 0;
long c = 0;
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Instead
- of:</i></span></p>
-
- <p>long a, b, c;</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Explanation:</i></span>
- - there is more room for comments on the individual variables -
- easier to add new variables without messing up the original ones -
- when searching on a variable to find its type, there is less clutter
- to "visually" eliminate</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Exceptions:</i></span>
- when you want to declare a bunch of loop variables or other trivial
- variables; feel free to declare them on one line. You should,
- although, provide a good comment on their functions.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span>
- developer-discretion.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S42" id="S42">4.7.6. Use malloc/zalloc
- sparingly</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>Create a local struct (on the stack) if the variable will live and
- die within the context of one function call.</p>
-
- <p>Only "malloc" a struct (on the heap) if the variable's life will
- extend beyond the context of one function call.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Instead of:</i></span>
+ </p>
+ <p>
+ long a, b, c;
+ </p>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span> - there is more room for
+ comments on the individual variables - easier to add new
+ variables without messing up the original ones - when searching
+ on a variable to find its type, there is less clutter to
+ "visually" eliminate
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Exceptions:</i></span>
+ when you want to declare a bunch of loop variables or other
+ trivial variables; feel free to declare them on one line. You
+ should, although, provide a good comment on their functions.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span>
+ developer-discretion.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S42">4.7.6. Use malloc/zalloc sparingly</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ Create a local struct (on the stack) if the variable will live
+ and die within the context of one function call.
+ </p>
+ <p>
+ Only "malloc" a struct (on the heap) if the variable's life will
+ extend beyond the context of one function call.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
If a function creates a struct and stores a pointer to it in a
list, then it should definitely be allocated via `malloc'.
</pre>
- </td>
- </tr>
- </table>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S43" id="S43">4.7.7. The Programmer Who
- Uses 'malloc' is Responsible for Ensuring 'free'</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>If you have to "malloc" an instance, you are responsible for
- insuring that the instance is `free'd, even if the deallocation event
- falls within some other programmer's code. You are also responsible
- for ensuring that deletion is timely (i.e. not too soon, not too
- late). This is known as "low-coupling" and is a "good thing (tm)".
- You may need to offer a free/unload/destructor type function to
- accommodate this.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S43">4.7.7. The Programmer Who Uses 'malloc' is
+ Responsible for Ensuring 'free'</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ If you have to "malloc" an instance, you are responsible for
+ insuring that the instance is `free'd, even if the deallocation
+ event falls within some other programmer's code. You are also
+ responsible for ensuring that deletion is timely (i.e. not too
+ soon, not too late). This is known as "low-coupling" and is a
+ "good thing (tm)". You may need to offer a free/unload/destructor
+ type function to accommodate this.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
int load_re_filterfile(struct client_state *csp) { ... }
static void unload_re_filterfile(void *f) { ... }
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Exceptions:</i></span></p>
-
- <p>The developer cannot be expected to provide `free'ing functions
- for C run-time library functions ... such as `strdup'.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Status:</i></span>
- developer-discretion. The "main" use of this standard is for
- allocating and freeing data structures (complex or nested).</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S44" id="S44">4.7.8. Add loaders to the
- `file_list' structure and in order</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>I have ordered all of the "blocker" file code to be in alpha
- order. It is easier to add/read new blockers when you expect a
- certain order.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> It may
- appear that the alpha order is broken in places by POPUP tests coming
- before PCRS tests. But since POPUPs can also be referred to as
- KILLPOPUPs, it is clear that it should come first.</p>
- </div>
-
- <div class="SECT3">
- <h3 class="SECT3"><a name="S45" id="S45">4.7.9. "Uncertain" new code
- and/or changes to existing code, use XXX</a></h3>
-
- <p><span class="emphasis"><i class=
- "EMPHASIS">Explanation:</i></span></p>
-
- <p>If you have enough confidence in new code or confidence in your
- changes, but are not *quite* sure of the repercussions, add this:</p>
-
- <p>/* XXX: this code has a logic error on platform XYZ, * attempting
- to fix */ #ifdef PLATFORM ...changed code here... #endif</p>
-
- <p>or:</p>
-
- <p>/* XXX: I think the original author really meant this... */
- ...changed code here...</p>
-
- <p>or:</p>
-
- <p>/* XXX: new code that *may* break something else... */ ...new code
- here...</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> If you
- make it clear that this may or may not be a "good thing (tm)", it
- will be easier to identify and include in the project (or conversely
- exclude from the project).</p>
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Exceptions:</i></span>
+ </p>
+ <p>
+ The developer cannot be expected to provide `free'ing functions
+ for C run-time library functions ... such as `strdup'.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Status:</i></span>
+ developer-discretion. The "main" use of this standard is for
+ allocating and freeing data structures (complex or nested).
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S44">4.7.8. Add loaders to the `file_list' structure and
+ in order</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ I have ordered all of the "blocker" file code to be in alpha
+ order. It is easier to add/read new blockers when you expect a
+ certain order.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> It
+ may appear that the alpha order is broken in places by POPUP
+ tests coming before PCRS tests. But since POPUPs can also be
+ referred to as KILLPOPUPs, it is clear that it should come first.
+ </p>
+ </div>
+ <div class="SECT3">
+ <h3 class="SECT3">
+ <a name="S45">4.7.9. "Uncertain" new code and/or changes to
+ existing code, use XXX</a>
+ </h3>
+ <p>
+ <span class="emphasis"><i class=
+ "EMPHASIS">Explanation:</i></span>
+ </p>
+ <p>
+ If you have enough confidence in new code or confidence in your
+ changes, but are not *quite* sure of the repercussions, add this:
+ </p>
+ <p>
+ /* XXX: this code has a logic error on platform XYZ, * attempting
+ to fix */ #ifdef PLATFORM ...changed code here... #endif
+ </p>
+ <p>
+ or:
+ </p>
+ <p>
+ /* XXX: I think the original author really meant this... */
+ ...changed code here...
+ </p>
+ <p>
+ or:
+ </p>
+ <p>
+ /* XXX: new code that *may* break something else... */ ...new
+ code here...
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> If
+ you make it clear that this may or may not be a "good thing
+ (tm)", it will be easier to identify and include in the project
+ (or conversely exclude from the project).
+ </p>
+ </div>
</div>
- </div>
-
- <div class="SECT2">
- <h2 class="SECT2"><a name="S46" id="S46">4.8. Addendum: Template for
- files and function comment blocks:</a></h2>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example for file
- comments:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-
<pre class="PROGRAMLISTING">
+ <div class="SECT2">
+ <h2 class="SECT2">
+ <a name="S46">4.8. Addendum: Template for files and function
+ comment blocks:</a>
+ </h2>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example for file
+ comments:</i></span>
+ </p>
+
<table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
const char FILENAME_rcs[] = "$I<!-- Break CVS Substitution -->d$";
/*********************************************************************
*
const char FILENAME_h_rcs[] = FILENAME_H_VERSION;
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> This
- declares the rcs variables that should be added to the
- "show-proxy-args" page. If this is a brand new creation by you, you are
- free to change the "Copyright" section to represent the rights you wish
- to maintain.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> The
- formfeed character that is present right after the comment flower box
- is handy for (X|GNU)Emacs users to skip the verbiage and get to the
- heart of the code (via `forward-page' and `backward-page'). Please
- include it if you can.</p>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example for file header
- comments:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
- <pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> This
+ declares the rcs variables that should be added to the
+ "show-proxy-args" page. If this is a brand new creation by you, you
+ are free to change the "Copyright" section to represent the rights
+ you wish to maintain.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> The
+ formfeed character that is present right after the comment flower
+ box is handy for (X|GNU)Emacs users to skip the verbiage and get to
+ the heart of the code (via `forward-page' and `backward-page').
+ Please include it if you can.
+ </p>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example for file header
+ comments:</i></span>
+ </p>
+ <table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
#ifndef _FILENAME_H
#define _FILENAME_H
#define FILENAME_H_VERSION "$I<!-- Break CVS Substitution -->d$"
end:
*/
</pre>
- </td>
- </tr>
- </table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Example for function
- comments:</i></span></p>
-
- <table border="0" bgcolor="#E0E0E0" width="100%">
- <tr>
- <td>
-
<pre class="PROGRAMLISTING">
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Example for function
+ comments:</i></span>
+ </p>
+
<table border="0" bgcolor="#E0E0E0" width="100%">
+ <tr>
+ <td>
+<pre class="PROGRAMLISTING">
/*********************************************************************
*
* Function : FUNCTION_NAME
}
</pre>
+ </td>
+ </tr>
+ </table>
+ <p>
+ <span class="emphasis"><i class="EMPHASIS">Note:</i></span> If we
+ all follow this practice, we should be able to parse our code to
+ create a "self-documenting" web page.
+ </p>
+ </div>
+ </div>
+ <div class="NAVFOOTER">
+ <hr align="LEFT" width="100%">
+ <table summary="Footer navigation table" width="100%" border="0"
+ cellpadding="0" cellspacing="0">
+ <tr>
+ <td width="33%" align="left" valign="top">
+ <a href="documentation.html" accesskey="P">Prev</a>
+ </td>
+ <td width="34%" align="center" valign="top">
+ <a href="index.html" accesskey="H">Home</a>
+ </td>
+ <td width="33%" align="right" valign="top">
+ <a href="testing.html" accesskey="N">Next</a>
+ </td>
+ </tr>
+ <tr>
+ <td width="33%" align="left" valign="top">
+ Documentation Guidelines
+ </td>
+ <td width="34%" align="center" valign="top">
+
+ </td>
+ <td width="33%" align="right" valign="top">
+ Testing Guidelines
</td>
</tr>
</table>
-
- <p><span class="emphasis"><i class="EMPHASIS">Note:</i></span> If we
- all follow this practice, we should be able to parse our code to create
- a "self-documenting" web page.</p>
</div>
- </div>
-
- <div class="NAVFOOTER">
- <hr align="left" width="100%">
-
- <table summary="Footer navigation table" width="100%" border="0"
- cellpadding="0" cellspacing="0">
- <tr>
- <td width="33%" align="left" valign="top"><a href=
- "documentation.html" accesskey="P">Prev</a></td>
-
- <td width="34%" align="center" valign="top"><a href="index.html"
- accesskey="H">Home</a></td>
-
- <td width="33%" align="right" valign="top"><a href="testing.html"
- accesskey="N">Next</a></td>
- </tr>
-
- <tr>
- <td width="33%" align="left" valign="top">Documentation
- Guidelines</td>
-
- <td width="34%" align="center" valign="top"> </td>
-
- <td width="33%" align="right" valign="top">Testing Guidelines</td>
- </tr>
- </table>
- </div>
-</body>
+ </body>
</html>
+
projects / privoxy.git / blobdiff