[BUG] is_power_of_2 of nuttx conflict

[nicolas71640]

Description / Steps to reproduce the issue

The compilation of botan with nuttx fails. It comes with the redefinition of is_power_of_2 function : declared in botan AND in nuttx int math32.h.

Here's the error with the chain of includes.

In file included from /build/nuttx/include/nuttx/clock.h:36,
                 from /build/nuttx/include/nuttx/semaphore.h:33,
                 from /build/nuttx/include/nuttx/mutex.h:31,
                 from /build/nuttx/include/nuttx/fs/fs.h:39,
                 from /build/nuttx/include/stdio.h:34,
                 from /build/nuttx/include/wchar.h:35,
                 from /build/nuttx/include/cxx/cwchar:30,
                 from /install/arm-none-eabi/include/c++/12.3.1/bits/postypes.h:40,
                 from /install/arm-none-eabi/include/c++/12.3.1/iosfwd:40,
                 from /install/arm-none-eabi/include/c++/12.3.1/ios:38,
                 from /install/arm-none-eabi/include/c++/12.3.1/ostream:38,
                 from /install/arm-none-eabi/include/c++/12.3.1/bits/unique_ptr.h:41,
                 from /install/arm-none-eabi/include/c++/12.3.1/memory:75,
                 from build/include/botan/types.h:17,
                 from build/include/botan/secmem.h:11,
                 from build/include/botan/symkey.h:11,
                 from build/include/botan/sym_algo.h:11,
                 from build/include/botan/block_cipher.h:11,
                 from build/include/botan/aes.h:11,
                 from src/lib/block/aes/aes.cpp:7:
build/include/botan/internal/bit_ops.h:43:39: error: expected ')' before 'arg'
   43 | inline constexpr bool is_power_of_2(T arg)

From what I understand, the nuttx libc shouldn't defined public functions outside of the one defines by the libc standard.

Any ideas how can we fix that ?

On which OS does this issue occur?

[OS: Linux]

What is the version of your OS?

Ubuntu 22

NuttX Version

master

Issue Architecture

[Arch: all]

Issue Area

[Area: Other]

Verification

• I have verified before submitting the report.

[TimJTi]

I had similar using LVGL (with the OS set to NuttX) also down to a conflict with a math32 function. I raised an issue on LVGL here

The proposal there was to rename.

I originally thought that it was incorrect use of static but I should have thought harder first. The scope of static is OK, and that's what LVGL used (in my case) but the math32.h uses #define macros for functions so the scope is pre-compile so will interfere with other libraries I think?

Should this NuttX library have "proper" static functions not #defines for these?

All a bit beyond my 2immediately to hand" experience so relying on a bit of Googling to refresh my aging memory, but surely there shouldn't be such library conflicts?

[xiaoxiang781216]

@GUIDINGLI look at this problem.

[TimJTi]

Also, [BUG] Compile warning due to __CONCAT redefinition #13562 is possibly related given the prevalence of #define functions/helpers in NuttX?

[GUIDINGLI]

How about this:
#13864

[GUIDINGLI]

Resolve, see the comments above.