Before this patch the mperrno.h file could be included and would silently
succeed with incorrect config settings, because mpconfig.h was not yet
included.
If constants (eg mp_const_none_obj) are placed in very high memory
locations that require 64-bits for the pointer then the assembler must be
able to emit instructions to move such pointers to one of the top 8
registers (ie r8-r15).
It's not used anywhere else in the VM loop, and clashes with (is shadowed
by) the n_state variable that's redeclared towards the end of the
mp_execute_bytecode function. Code size is unchanged.
The code conventions suggest using header guards, but do not define how
those should look like and instead point to existing files. However, not
all existing files follow the same scheme, sometimes omitting header guards
altogether, sometimes using non-standard names, making it easy to
accidentally pick a "wrong" example.
This commit ensures that all header files of the MicroPython project (that
were not simply copied from somewhere else) follow the same pattern, that
was already present in the majority of files, especially in the py folder.
The rules are as follows.
Naming convention:
* start with the words MICROPY_INCLUDED
* contain the full path to the file
* replace special characters with _
In addition, there are no empty lines before #ifndef, between #ifndef and
one empty line before #endif. #endif is followed by a comment containing
the name of the guard macro.
py/grammar.h cannot use header guards by design, since it has to be
included multiple times in a single C file. Several other files also do not
need header guards as they are only used internally and guaranteed to be
included only once:
* MICROPY_MPHALPORT_H
* mpconfigboard.h
* mpconfigport.h
* mpthreadport.h
* pin_defs_*.h
* qstrdefs*.h
Damien George
Matthew Brener
Paul Sokolovsky
Alexander Steffen
Peter Hinch
Piotr Maliński
Tom Collins
Alex Robbins