- Indentation in tabs, 8 characters wide, spaces after the tabs where vertical alignment is required (see below) - Max line width 80ch, do not break up printed strings though - Break up long lines at logical groupings, one line for each logical group int a = somelongname() + someotherlongname(); if (a < 0 && (b > 20 & d < 10) && d != 0.0) somelongfunctioncall(arg1, arg2, arg3); - Function declarations: return type on separate line, {} on separate line, arguments broken up as above. static inline int foobar(int a, int b) { } void somenamethatiswaytoolong(int a, int b, int c) { } - /* comments only */, no // comments - variable_name, not VariableName or variableName. same for functions. - no typedefs of structs, enums, unions - if it generates a compiler warning, it needs to be fixed - if it generates a static checker warning, it needs to be fixed or commented - declare variables at the top, try to keep them as local as possible. Exception: if the same variable is re-used in multiple blocks, declare it at the top. int a; int c; if (foo) { int b; c = get_value(); usevalue(c); } if (bar) { c = get_value(); useit(c); } - do not mix function invocations and variable definitions. wrong: { int a = foo(); int b = 7; } right: { int a; int b = 7; a = foo(); } There are exceptions here, e.g. tp_libinput_context(), litest_current_device() - if/else: { on the same line, no curly braces if both blocks are a single statement. If either if or else block are multiple statements, both must have curly braces. if (foo) { blah(); bar(); } else { a = 10; } - public functions MUST be doxygen-commented, use doxygen's @foo rather than \foo notation - include "config.h" comes first, followed by system headers, followed by external library headers, followed by internal headers. sort alphabetically where it makes sense (specifically system headers) #include "config.h" #include #include #include #include "libinput-private.h" - goto jumps only to the end of the function, and only for good reasons (usually cleanup). goto never jumps backwards - Use stdbool.h's bool for booleans within the library (instead of 'int'). Exception: the public API uses int, not bool.