diff options
Diffstat (limited to 'Documentation/CodingGuidelines')
| -rw-r--r-- | Documentation/CodingGuidelines | 102 |
1 files changed, 87 insertions, 15 deletions
diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines index 894546dd75..a4191aa388 100644 --- a/Documentation/CodingGuidelines +++ b/Documentation/CodingGuidelines @@ -1,5 +1,5 @@ Like other projects, we also have some guidelines to keep to the -code. For Git in general, three rough rules are: +code. For Git in general, a few rough rules are: - Most importantly, we never say "It's in POSIX; we'll happily ignore your needs should your system not conform to it." @@ -171,6 +171,11 @@ For C programs: - We try to keep to at most 80 characters per line. + - As a Git developer we assume you have a reasonably modern compiler + and we recommend you to enable the DEVELOPER makefile knob to + ensure your patch is clear of all compiler warnings we care about, + by e.g. "echo DEVELOPER=1 >>config.mak". + - We try to support a wide range of C compilers to compile Git with, including old ones. That means that you should not use C99 initializers, even if a lot of compilers grok it. @@ -201,11 +206,38 @@ For C programs: x = 1; } - is frowned upon. A gray area is when the statement extends - over a few lines, and/or you have a lengthy comment atop of - it. Also, like in the Linux kernel, if there is a long list - of "else if" statements, it can make sense to add braces to - single line blocks. + is frowned upon. But there are a few exceptions: + + - When the statement extends over a few lines (e.g., a while loop + with an embedded conditional, or a comment). E.g.: + + while (foo) { + if (x) + one(); + else + two(); + } + + if (foo) { + /* + * This one requires some explanation, + * so we're better off with braces to make + * it obvious that the indentation is correct. + */ + doit(); + } + + - When there are multiple arms to a conditional and some of them + require braces, enclose even a single line block in braces for + consistency. E.g.: + + if (foo) { + doit(); + } else { + one(); + two(); + three(); + } - We try to avoid assignments in the condition of an "if" statement. @@ -328,9 +360,14 @@ For C programs: - When you come up with an API, document it. - - The first #include in C files, except in platform specific - compat/ implementations, should be git-compat-util.h or another - header file that includes it, such as cache.h or builtin.h. + - The first #include in C files, except in platform specific compat/ + implementations, must be either "git-compat-util.h", "cache.h" or + "builtin.h". You do not have to include more than one of these. + + - A C file must directly include the header files that declare the + functions and the types it uses, except for the functions and types + that are made available to it by including one of the header files + it must include by the previous rule. - If you are planning a new command, consider writing it in shell or perl first, so that changes in semantics can be easily @@ -413,6 +450,29 @@ Error Messages - Say what the error is first ("cannot open %s", not "%s: cannot open") +Externally Visible Names + + - For configuration variable names, follow the existing convention: + + . The section name indicates the affected subsystem. + + . The subsection name, if any, indicates which of an unbounded set + of things to set the value for. + + . The variable name describes the effect of tweaking this knob. + + The section and variable names that consist of multiple words are + formed by concatenating the words without punctuations (e.g. `-`), + and are broken using bumpyCaps in documentation as a hint to the + reader. + + When choosing the variable namespace, do not use variable name for + specifying possibly unbounded set of things, most notably anything + an end user can freely come up with (e.g. branch names). Instead, + use subsection names or variable values, like the existing variable + branch.<name>.description does. + + Writing Documentation: Most (if not all) of the documentation pages are written in the @@ -441,6 +501,10 @@ Writing Documentation: --sort=<key> --abbrev[=<n>] + If a placeholder has multiple words, they are separated by dashes: + <new-branch-name> + --template=<template-directory> + Possibility of multiple occurrences is indicated by three dots: <file>... (One or more of <file>.) @@ -457,12 +521,12 @@ Writing Documentation: (Zero or more of <patch>. Note that the dots are inside, not outside the brackets.) - Multiple alternatives are indicated with vertical bar: + Multiple alternatives are indicated with vertical bars: [-q | --quiet] [--utf8 | --no-utf8] Parentheses are used for grouping: - [(<rev>|<range>)...] + [(<rev> | <range>)...] (Any number of either <rev> or <range>. Parens are needed to make it clear that "..." pertains to both <rev> and <range>.) @@ -489,12 +553,20 @@ Writing Documentation: modifying paragraphs or option/command explanations that contain options or commands: - Literal examples (e.g. use of command-line options, command names, and - configuration variables) are typeset in monospace, and if you can use - `backticks around word phrases`, do so. + Literal examples (e.g. use of command-line options, command names, + branch names, configuration and environment variables) must be + typeset in monospace (i.e. wrapped with backticks): `--pretty=oneline` `git rev-list` - `remote.pushdefault` + `remote.pushDefault` + `GIT_DIR` + `HEAD` + + An environment variable must be prefixed with "$" only when referring to its + value and not when referring to the variable itself, in this case there is + nothing to add except the backticks: + `GIT_DIR` is specified + `$GIT_DIR/hooks/pre-receive` Word phrases enclosed in `backtick characters` are rendered literally and will not be further expanded. The use of `backticks` to achieve the |