diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/internals/contributing/coding-style.rst | 52 |
1 files changed, 31 insertions, 21 deletions
diff --git a/Documentation/internals/contributing/coding-style.rst b/Documentation/internals/contributing/coding-style.rst index 666e887b1..63a36812a 100644 --- a/Documentation/internals/contributing/coding-style.rst +++ b/Documentation/internals/contributing/coding-style.rst @@ -542,34 +542,44 @@ them, e.g. : alpheus_output_control(dp, skb, fwd_save_skb(skb), VIGR_ACTION)); -Do not parenthesize the operands of ``&&`` and ``||`` unless operator -precedence makes it necessary, or unless the operands are themselves -expressions that use ``&&`` and ``||``. Thus: - -:: - - if (!isdigit((unsigned char)s[0]) - || !isdigit((unsigned char)s[1]) - || !isdigit((unsigned char)s[2])) { - printf("string %s does not start with 3-digit code\n", s); - } - -but - -:: +Parenthesize the operands of ``&&`` and ``||`` if operator precedence makes it +necessary, or if the operands are themselves expressions that use ``&&`` and +``||``, but not otherwise. Thus:: if (rule && (!best || rule->priority > best->priority)) { best = rule; } -Do parenthesize a subexpression that must be split across more than one line, -e.g.: +but:: -:: + if (!isdigit((unsigned char)s[0]) || + !isdigit((unsigned char)s[1]) || + !isdigit((unsigned char)s[2])) { + printf("string %s does not start with 3-digit code\n", s); + } - *idxp = ((l1_idx << PORT_ARRAY_L1_SHIFT) - | (l2_idx << PORT_ARRAY_L2_SHIFT) - | (l3_idx << PORT_ARRAY_L3_SHIFT)); +Do parenthesize a subexpression that must be split across more than one line, +e.g.:: + + *idxp = ((l1_idx << PORT_ARRAY_L1_SHIFT) | + (l2_idx << PORT_ARRAY_L2_SHIFT) | + (l3_idx << PORT_ARRAY_L3_SHIFT)); + +Breaking a long line after a binary operator gives its operands a more +consistent look, since each operand has the same horizontal position. This +makes the end-of-line position a good choice when the operands naturally +resemble each other, as in the previous two examples. On the other hand, +breaking before a binary operator better draws the eye to the operator, which +can help clarify code by making it more obvious what's happening, such as in +the following example:: + + if (!ctx.freezing + && xbridge->has_in_band + && in_band_must_output_to_local_port(flow) + && !actions_output_to_local_port(&ctx)) { + +Thus, decide whether to break before or after a binary operator separately in +each situation, based on which of these factors appear to be more important. Try to avoid casts. Don't cast the return value of malloc(). |