Tech memory

[sangallidavide]

This is an example of the idea of changing the logic of
#include<memory.h>
in order to move it in the header section of the source.

It does not need to be merged. Changes can be easily transferred to other branches thanks to this bask / awk script
https://github.com/sangallidavide/yambo/blob/tech-memory/sbin/move_include_files.sh

Just to link an example of a file after the action of the script (header at the top, implicit none in the source)
https://github.com/sangallidavide/yambo/blob/tech-memory/src/bse/K_blocks.F

Other relevant changes are here:
https://github.com/sangallidavide/yambo/blob/tech-memory/include/headers/common/y_memory.h

[andreamarini]

I do think that the use of macros should be avoided.

In the maintenance/master I fixed a problem in K_blocks where the lines

 integer(IPL) :: HOST_SIZE(1),TMP_SIZE,LOCAL_SIZE(1)

are there to provide y_memory.h with pieces of modules.

In this way something is declared but not used in routine body but in a macro.

This makes the code difficult to read and with hidden dependencies.

[sangallidavide]

I think we do not want to remove all the macros, e.g. remove YAMBO_ALLOC.

However, I agree there is an asymmetry between this explicit declaration
integer(IPL) :: HOST_SIZE(1),TMP_SIZE,LOCAL_SIZE(1)
and the use of the macro YAMBO_PAR_ALLOC.

I've seen the proposed solution, but it forces back the header to be put inside the fortran code.

A possible solutions, which can merge the two things, is defining:

define YAMBO_PAR_ALLOC_DEFS \
integer(IPL) :: HOST_SIZE(1),TMP_SIZE,LOCAL_SIZE(1)

and similarly

use    y_memory   ONLY: ... ``

Doing so, in the main source, only `YAMBO_PAR_ALLOC` and `YAMBO_PAR_ALLOC_DEF` and `USE_PAR_MEMORY` would appear.