Redefine error when using C++

[EricB-ADI]

I am working on an internal project with c++.

I am getting a redefinition error

In file included from /home/eric-busch/Workspace/msdk/Libraries/CMSIS/Device/Maxim/MAX32655/Include/max32655.h:257,
                 from /home/eric-busch/Workspace/msdk/Libraries/PeriphDrivers/Include/MAX32655/mxc_device.h:24,
                 from ../../../../../Libraries/RF-PHY/MAX32655/include/dbb_registers.h:51,
                 from inc/tester.hpp:14,
                 from src/tester.cpp:7:

core_cm4.h:222: warning: "__I" redefined

where it is previously defined

gpio_regs.h:53: note: this is the location of the previous definition

core_cm4.h

#ifdef __cplusplus
  #define   __I     volatile             /*!< Defines 'read only' permissions */
#else
  #define   __I     volatile const       /*!< Defines 'read only' permissions */
#endif
#define     __O     volatile             /*!< Defines 'write only' permissions */
#define     __IO    volatile             /*!< Defines 'read / write' permissions */

/* following defines should be used for structure members */
#define     __IM     volatile const      /*! Defines 'read only' structure member permissions */
#define     __OM     volatile            /*! Defines 'write only' structure member permissions */
#define     __IOM    volatile            /*! Defines 'read / write' structure member permissions */

What doesn't make sense to me is volatile const basically says its hardware that can only be read by the software, which makes sense for the input. Why c++ matters is beyond me. Seems like a bug, but is clearly intentional.

gpio_regs.h

#ifndef __IO
#define __IO volatile
#endif
#ifndef __I
#define __I  volatile const
#endif
#ifndef __O
#define __O  volatile
#endif
#ifndef __R
#define __R  volatile const
#endif

There must be some place core_cm4.h is getting included after gpio_regs.h
Only reason it is not an issue before is the defs are the same when using c.

Option 1: basically copy the core_cm4.h files. or

It looks like this

#ifndef __IO
#define __IO volatile
#endif
#ifndef __I
#ifdef __cplusplus
  #define   __I     volatile             /*!< Defines 'read only' permissions */
#else
  #define   __I     volatile const       /*!< Defines 'read only' permissions */
#endif
#endif
#ifndef __O
#define __O volatile
#endif
#ifndef __R
#define __R volatile const
#endif

Only gpio_regs.h and dbb_ctrl_regs.h have this issue.

Option 2: #include "core_cm4.h" and only define __R

If you have a better idea let me know.

@sihyung-maxim @Jake-Carter

[Jake-Carter]

@EricB-ADI can you attach that tester.hpp file? Having a hard time replicating

[EricB-ADI]

@ttmut Linked this https://developer.arm.com/documentation/ka002980/latest

Yes, it should be updated as const will get optimized volatile or not.
The register script is in an internal repo, so I can play with it there.

[EricB-ADI]

Addressed in #1228