4.7 Symbol naming rules
ARM® syntax assembly code and GNU syntax assembly code use similar, but different naming rules for symbols.
Symbol naming rules which are common to both ARM syntax and GNU syntax include:
- Symbol names must be unique within their scope.
- Symbol names are case-sensitive, and all characters in the symbol name are significant.
- Symbols must not use the same name as built-in variable names or predefined symbol names.
Symbol naming rules which differ between ARM syntax and GNU syntax include:
ARM syntax symbols must start with a letter or the underscore character "_".
GNU syntax symbols must start with a letter, the underscore character "_", or a period ".".
ARM syntax symbols use double bars to delimit symbol names containing non-alphanumeric characters (except for the underscore):
GNU syntax symbols do not require double bars: