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diff --git a/eng/coding-80cols.rst b/eng/coding-80cols.rst deleted file mode 100644 index 85b838a..0000000 --- a/eng/coding-80cols.rst +++ /dev/null @@ -1,154 +0,0 @@ -.. SPDX-License-Identifier: CC-BY-SA-4.0 - -.. Copyright (C) 2018. -.. COMMENT: RTEMS Foundation, The RTEMS Documentation Project - -Eighty Character Line Limit -*************************** - -.. COMMENT: TBD - Convert the following to Rest and insert into this file -.. COMMENT: TBD - https://devel.rtems.org/wiki/Developer/Coding/80_characters_per_line - - Code should look good for everyone under some standard width assumptions. - Where a line wraps should be the same for anyone reading the code. For - historical reasons, RTEMS uses 80 characters as the maximum width for each - line of code. - -If you find yourself with code longer than 80 characters, first ask yourself -whether the nesting level is too deep, names too long, compound expressions too -complicated, or if some other guideline for improving readability can help to -shrink the line length. Refactoring nested blocks into functions can help to -alleviate code width problems while improving code readability. Making names -descriptive yet terse can also improve readability. If absolutely necessary -to have a long line, follow the rules on this page to break the line up to adhere -to the 80 characters per line rule. - -Breaking long lines -------------------- - -``if``, ``while``, and ``for`` loops have their condition expressions aligned -and broken on separate lines. When the conditions have to be broken, none go on -the first line with the ``if``, ``while``, or ``for`` statement, and none go on -the last line with the closing parenthesis and (optional) curly brace. Long -statements are broken up and indented at operators, with an operator always -being the last token on a line. No blank spaces should be left at the end of -any line. Here is an example with a ``for`` loop. - -.. code-block:: c - - for ( initialization = statement; a + really + long + statement + that + evaluates + to < a + boolean; another + statement++ ) { - z = a + really + long + statement + that + needs + two + lines + gets + indented + four + more + spaces + on + the + second + and + subsequent + lines + and + broken + up + at + operators; - } - -Should be replaced with - -.. code-block:: c - - for ( - initialization = statement; - a + really + long + statement + that + evaluates + to < - a + boolean; - another + statement++ - ) { - z = a + really + long + statement + that + needs + - two + lines + gets + indented + four + more + - spaces + on + the + second + and + subsequent + - lines + and + broken + up + at + operators; - } - -Note that indentations should add 2 nesting levels (4 space characters, not tabs). - -Similarly, - -.. code-block:: c - - if ( this + that < those && this + these < that && this + those < these && this < those && those < that ) { - -should be broken up like - -.. code-block:: c - - if ( - this + that < those && - this + these < that && - this + those < these && - this < those && - those < that - ) { - -Note that each expression that resolves to a boolean goes on its own line. -Where you place the boolean operator is a matter of choice. - -When a line is long because of a comment at the end, move the comment to -just before the line, for example - -.. code-block:: c - - #define A_LONG_MACRO_NAME (AND + EXPANSION) /* Plus + a + really + long + comment */ - -can be replaced with - -.. code-block:: c - - /* Plus + a + really + long + comment */ - #define A_LONG_MACRO_NAME (AND + EXPANSION) - -C Preprocessor macros need to be broken up with some care, because the -preprocessor does not understand that it should eat newline characters. So - -.. code-block:: c - - #define A_LONG_MACRO_NAME (AND + EXCESSIVELY + LONG + EXPANSION + WITH + LOTS + OF + EXTRA + STUFF + DEFINED) - -would become - -.. code-block:: c - - #define A_LONG_MACRO_NAME ( \ - AND + EXCESSIVELY + LONG + EXPANSION + WITH + LOTS + OF + EXTRA + STUFF + \ - DEFINED \ - ) - -Notice that each line is terminated by a backslash then the carriage return. -The backslash tells the preprocessor to eat the newline. Of course, if you have -such a long macro, you should consider not using a macro. - -Function declarations can be broken up at each argument, for example - -.. code-block:: c - - int this_is_a_function( int arg1, int arg2, int arg3, int arg4, int arg5, int arg6, int arg7, int arg8, int arg9 ); - -would be broken up as - -.. code-block:: c - - int this_is_a_function( - int arg1, - int arg2, - int arg3, - int arg4, - int arg5, - int arg6, - int arg7, - int arg8, - int arg9 - ); - -Excessively long comments should be broken up at a word boundary or somewhere -that makes sense, for example - -.. code-block:: c - - /* Excessively long comments should be broken up at a word boundary or somewhere that makes sense, for example */ - -would be - -.. code-block:: c - - /* Excessively long comments should be broken up at a word boundary or - * somewhere that makes sense, for example */ - -Note that multiline comments have a single asterisk aligned with the asterisk -in the opening ``/*``. The closing ``*/`` should go at the end of the last -line. |