diff options
Diffstat (limited to 'Documentation/CodingGuidelines')
| -rw-r--r-- | Documentation/CodingGuidelines | 41 |
1 files changed, 26 insertions, 15 deletions
diff --git a/Documentation/CodingGuidelines b/Documentation/CodingGuidelines index f45db5b727..e3af089ecf 100644 --- a/Documentation/CodingGuidelines +++ b/Documentation/CodingGuidelines @@ -75,7 +75,7 @@ For shell scripts specifically (not exhaustive): - If you want to find out if a command is available on the user's $PATH, you should use 'type <command>', instead of 'which <command>'. - The output of 'which' is not machine parseable and its exit code + The output of 'which' is not machine parsable and its exit code is not reliable across platforms. - We use POSIX compliant parameter substitutions and avoid bashisms; @@ -91,16 +91,10 @@ For shell scripts specifically (not exhaustive): - No shell arrays. - - No strlen ${#parameter}. - - No pattern replacement ${parameter/pattern/string}. - We use Arithmetic Expansion $(( ... )). - - Inside Arithmetic Expansion, spell shell variables with $ in front - of them, as some shells do not grok $((x)) while accepting $(($x)) - just fine (e.g. dash older than 0.5.4). - - We do not use Process Substitution <(list) or >(list). - Do not write control structures on a single line with semicolon. @@ -181,6 +175,11 @@ For shell scripts specifically (not exhaustive): does not have such a problem. + - Even though "local" is not part of POSIX, we make heavy use of it + in our test suite. We do not use it in scripted Porcelains, and + hopefully nobody starts using "local" before they are reimplemented + in C ;-) + For C programs: @@ -203,7 +202,7 @@ For C programs: . since early 2012 with e1327023ea, we have been using an enum definition whose last element is followed by a comma. This, like an array initializer that ends with a trailing comma, can be used - to reduce the patch noise when adding a new identifer at the end. + to reduce the patch noise when adding a new identifier at the end. . since mid 2017 with cbc0f81d, we have been using designated initializers for struct (e.g. "struct t v = { .val = 'a' };"). @@ -238,6 +237,18 @@ For C programs: while( condition ) func (bar+1); + - Do not explicitly compare an integral value with constant 0 or '\0', + or a pointer value with constant NULL. For instance, to validate that + counted array <ptr, cnt> is initialized but has no elements, write: + + if (!ptr || cnt) + BUG("empty array expected"); + + and not: + + if (ptr == NULL || cnt != 0); + BUG("empty array expected"); + - We avoid using braces unnecessarily. I.e. if (bla) { @@ -483,21 +494,21 @@ For Python scripts: - We follow PEP-8 (http://www.python.org/dev/peps/pep-0008/). - - As a minimum, we aim to be compatible with Python 2.6 and 2.7. + - As a minimum, we aim to be compatible with Python 2.7. - Where required libraries do not restrict us to Python 2, we try to also be compatible with Python 3.1 and later. - - When you must differentiate between Unicode literals and byte string - literals, it is OK to use the 'b' prefix. Even though the Python - documentation for version 2.6 does not mention this prefix, it has - been supported since version 2.6.0. - Error Messages - Do not end error messages with a full stop. - - Do not capitalize ("unable to open %s", not "Unable to open %s") + - Do not capitalize the first word, only because it is the first word + in the message ("unable to open %s", not "Unable to open %s"). But + "SHA-3 not supported" is fine, because the reason the first word is + capitalized is not because it is at the beginning of the sentence, + but because the word would be spelled in capital letters even when + it appeared in the middle of the sentence. - Say what the error is first ("cannot open %s", not "%s: cannot open") |