Naming Rules

6.3.6. Naming Rules#

6.3.6.1. General Rules#

  • Avoid abbreviations.

    • Exception: When the abbreviation is more common than the full word.

    • Exception: For well-known acronyms.

  • Use descriptive language.

  • File names should be lower-case alphabet letters only, plus the extension. Avoid symbols in file names.

    • Exception: Use a single underscore _ or hyphen - to separate words in file names.

  • Prefer to use underscores (Snake_Case) to separate words, rather than CamelCase or TitleCase.

  • Local-scope variable names are all lower case with underscores between words.

  • CPP macros are all capital letters with underscores between words.

  • Enumerated (enum) values are all capital letters with underscores between words, but the type name follows the regular rules of other type names.

  • Constant (const) variables follow the same rules as other variables. An exception is that a const that replaces a CPP macro might be all capital letters for backward compatibility.

  • Type names, function names, and global scope names have different rules depending on whether they are part of the public API or are internal to RTEMS, see below.

6.3.6.2. User-facing API#

The public API routines follow a standard API like POSIX or BSD or start with rtems_. If a name starts with rtems_, then it should be assumed to be available for use by the application and be documented in the User’s Guide.

The POSIX API follows the rules of POSIX.

6.3.6.3. RTEMS internal interfaces#

The SuperCore (cpukit/score) or “score” is organized in an object-oriented fashion. Each score Manager is a Package (or Module), and each Module contains type definitions, functions, etc. The following summarizes our conventions for using names within SuperCore Modules:

  • Use Module_name_Particular_type_name for type names.

  • Use _Module_name_Particular_function_name for function names.

  • Use _Module_name_Global_or_file_scope_variable_name for global or file scope variable names.

  • Within a structure:

    • Use Name for struct aggregate members.

    • Use name for reference members.

    • Use name for primitive type members.

    • Example:

      typedef struct {
  Other_module_Struct_type    Aggregate_member_name;
  Other_module_Struct_type   *reference_member_name;
  Other_module_Primitive_type primitive_member_name;
} The_module_Type_name;