1 # DarkPlaces Contributing Guidelines
2 -------------------------------------------------------------------------------
4 1. ### Do not break Quake or its mods, and any other game using the engine.
6 The engine has known compatibility issues with Quake and many community
7 mods. All code must not make the situation worse. This is analogous to the policy
8 of the Linux kernel to not break userspace.
10 2. ### Sign off all of your commits if they are to be included upstream.
12 You must use a valid, permanent email address.
14 2. ### All code submitted should follow the Allman style for the most part.
16 1. In statements, the curly brace should be placed on the next line at the
17 same indentation level as the statement. If the statement only involves
18 a single line, do not use curly braces.
28 Do_Something_Else_Else();
31 Do_Something_Else_Else_Else();
34 2. Use tabs for indentation.
36 Use spaces subsequently for alignment of the
37 parameters of multi-line function calls or declarations, or statements.
41 if(very_long_statement &&
42 very_long_statement_aligned &&
53 3. If possible, try to keep individual lines of code less than 100
56 4. Pointer operators should be placed on the right-hand side.
63 5. Type casts should have a space between the type and the pointer.
66 int *foo = (int *)malloc(5);
69 6. Use spaces after each comma when listing parameters or variables of a
72 7. Multi-line comments should be formatted like so:
76 * This is a multi-line comment.
77 * Sometimes, I dream about cheese.
84 /* This is another multi-line comment.
89 8. If following these guidelines in any manner would make any code less
90 readable or harder to follow, ***ignore them***. This section is only
91 guidelines, not rules. We're not gonna beat you over the head in pull
92 requests because you misplaced a dereference operator.
94 For example, in some situations, placing the block on the same line as
95 the condition would be okay because it looks cleaner:
98 if (foo) Do_Something();
99 if (bar) Do_Something_Else();
101 if (boo) AHH("!!!\n");
104 4. DarkPlaces is written in the common subset of C and C++. This means it is
105 (usually) both valid C and C++. We historically wanted to keep it that way,
106 but don't worry about it unless you care enough and/or are a maintainer.
108 Most of the differences are caught by `-Wc++-compat` but some are subtle
109 and would cause behavior differences between the two compilers, or are not
110 caught by that warning. The things to look out for are:
112 1. Character constants are `int`-sized in C but `char`-sized in C++. This
113 means `sizeof('a')` will be 4 in C, but 1 in C++.
115 2. `goto label;` cannot jump over a variable initialization. This will
116 cause a compiler error as C++ but is not caught by `-Wc++-compat`.
117 This is nevertheless bad code, so avoid this anyway.
119 If, for some reason, you care enough, compatibility can always be tested
120 affirmatively by setting CC=g++. CC=clang++ may not work in the future, if
121 it didn't already stop working in current versions of LLVM, as it otherwise
122 spams deprecation warnings for using a C file as input to a C++ compiler.
125 > We do not officially support building C code with a C++ compiler and may not
126 > address issue reports for buggy behavior that does not occur when compiled
127 > with a C compiler. That said, there have been fleeting ideas for converting
128 > either the entire engine or parts of it to C++, which is what `-Wc++-compat`
129 > would make a little easier. So, we at least *do not discourage* such issue
130 > reports, especially for things the warning doesn't catch. They will be noted
131 > as they would become relevant in the event we do decide to convert to C++.