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.
+ including old ones. You should not use features from newer C
+ standard, even if your compiler groks them.
- - Variables have to be declared at the beginning of the block.
+ There are a few exceptions to this guideline:
+
+ . 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.
+
+ . since mid 2017 with cbc0f81d, we have been using designated
+ initializers for struct (e.g. "struct t v = { .val = 'a' };").
+
+ . since mid 2017 with 512f41cf, we have been using designated
+ initializers for array (e.g. "int array[10] = { [5] = 2 }").
+
+ These used to be forbidden, but we have not heard any breakage
+ report, and they are assumed to be safe.
+
+ - Variables have to be declared at the beginning of the block, before
+ the first statement (i.e. -Wdeclaration-after-statement).
+
+ - Declaring a variable in the for loop "for (int i = 0; i < 10; i++)"
+ is still not allowed in this codebase.
- NULL pointers shall be written as NULL, not as 0.