GRPC C STYLE GUIDE ===================== Background ---------- Here we document style rules for C usage in the gRPC Core library. General ------- - Layout rules are defined by clang-format, and all code should be passed through clang-format. A (docker-based) script to do so is included in [tools/distrib/clang\_format\_code.sh] (../tools/distrib/clang_format_code.sh). Header Files ------------ - Public header files (those in the include/grpc tree) should compile as pedantic C89 - Public header files should be includable from C++ programs. That is, they should include the following: ```c #ifdef __cplusplus extern "C" { # endif /* ... body of file ... */ #ifdef __cplusplus } # endif ``` - Header files should be self-contained and end in .h. - All header files should have a #define guard to prevent multiple inclusion. To guarantee uniqueness they should be based on the file's path. For public headers: include/grpc/grpc.h --> GRPC_GRPC_H For private headers: src/core/channel/channel_stack.h --> GRPC_INTERNAL_CORE_CHANNEL_CHANNEL_STACK_H C99 Features ------------ - Variable sized arrays are not allowed - Do not use the 'inline' keyword - Flexible array members are allowed (https://en.wikipedia.org/wiki/Flexible_array_member) Comments -------- Within public header files, only `/* */` comments are allowed. Within implementation files and private headers, either single line `//` or multi line `/* */` comments are allowed. Only one comment style per file is allowed however (i.e. if single line comments are used anywhere within a file, ALL comments within that file must be single line comments). Symbol Names ------------ - Non-static functions must be prefixed by grpc_ - static functions must not be prefixed by grpc_ - enumeration values and #define names are uppercased, all others are lowercased - Multiple word identifiers use underscore as a delimiter (NEVER camel casing)