Cpp compiling error: expected primary-expression before 'char'. _Generic macros problem

[DariusBabrauskas]

Describe the bug

Compile error if use call LOG_DBG(...) from cpp code.

Error example:
error: expected primary-expression before 'char'.

To Reproduce
Simple try compile cpp file with code:
// Type your code here, or load an example.

// C program to illustrate macro function.
#include <stdio.h>
#define geeks(T) _Generic( (T), char: 1, int: 2, long: 3, default: 0)
int main(void)
{
// char returns ASCII value which is int type.
printf("%d\n", geeks('A'));

// Here A is a string.
printf("%d",geeks("A"));
  
return 0;

}

You can test it on different compilers her. I found that clang from 3.5 cpp support _Generic - but result different if compile c file.
https://godbolt.org/z/jf1o41co5

Expected behavior

Impact

Logs and console output
../zephyr/include/sys/cbprintf_internal.h:75:4: error: expected primary-expression before 'char'
75 | char * : 1,
| ^~~~
../zephyr/include/sys/util_internal.h:67:26: note: in definition of macro '__DEBRACKET'
67 | #define __DEBRACKET(...) VA_ARGS
| ^~~~~~~~~~~
../zephyr/include/sys/util_internal.h:59:2: note: in expansion of macro '__GET_ARG2_DEBRACKET'
59 | __GET_ARG2_DEBRACKET(one_or_two_args _if_code, _else_code)
| ^~~~~~~~~~~~~~~~~~~~
../zephyr/include/sys/util_internal.h:56:2: note: in expansion of macro '__COND_CODE'
56 | __COND_CODE(_ZZZZ##_flag, _if_0_code, _else_code)
| ^~~~~~~~~~~
../zephyr/include/sys/util_macro.h:133:2: note: in expansion of macro 'Z_COND_CODE_0'
133 | Z_COND_CODE_0(_flag, _if_0_code, _else_code)
| ^~~~~~~~~~~~~
../zephyr/include/sys/cbprintf_internal.h:110:2: note: in expansion of macro 'COND_CODE_0'
110 | COND_CODE_0(NUM_VA_ARGS_LESS_1(VA_ARGS),
| ^~~~~~~~~~~
../zephyr/include/sys/util_loops.h:1075:2: note: in expansion of macro 'Z_CBPRINTF_IS_PCHAR'
1075 | fixed_arg0(x)
| ^~~~~~~~~~
../zephyr/include/sys/util_loops.h:28:2: note: in expansion of macro 'Z_FOR_EACH_EXEC'
28 | z_call(0, x, fixed_arg0, fixed_arg1)
| ^~~~~~
../zephyr/include/sys/util_loops.h:31:2: note: in expansion of macro 'Z_FOR_LOOP_1'
31 | Z_FOR_LOOP_1(z_call, sep, fixed_arg0, fixed_arg1, ##VA_ARGS)
| ^~~~~~~~~~~~
../zephyr/include/sys/util_loops.h:36:2: note: in expansion of macro 'Z_FOR_LOOP_2'
36 | Z_FOR_LOOP_2(z_call, sep, fixed_arg0, fixed_arg1, ##VA_ARGS)
| ^~~~~~~~~~~~
../zephyr/include/sys/util_loops.h:23:53: note: in expansion of macro 'Z_FOR_LOOP_3'
23 | _57, _58, _59, _60, _61, _62, _63, _64, N, ...) N
| ^
../zephyr/include/sys/util_loops.h:1078:2: note: in expansion of macro 'Z_FOR_EACH_ENGINE'
1078 | Z_FOR_EACH_ENGINE(Z_FOR_EACH_EXEC, sep, F, _, VA_ARGS)
| ^~~~~~~~~~~~~~~~~
../zephyr/include/sys/util_macro.h:371:2: note: in expansion of macro 'Z_FOR_EACH'
371 | Z_FOR_EACH(F, sep, REVERSE_ARGS(VA_ARGS))
| ^~~~~~~~~~
../zephyr/include/sys/cbprintf_internal.h:95:3: note: in expansion of macro 'FOR_EACH'
95 | (FOR_EACH(Z_CBPRINTF_IS_PCHAR, (+), VA_ARGS))
| ^~~~~~~~
../zephyr/include/sys/cbprintf_internal.h:112:7: note: in expansion of macro 'Z_CBPRINTF_HAS_PCHAR_ARGS'
112 | (((Z_CBPRINTF_HAS_PCHAR_ARGS(VA_ARGS) - skip) > 0)))
| ^~~~~~~~~~~~~~~~~~~~~~~~~
../zephyr/include/sys/cbprintf.h:92:2: note: in expansion of macro 'Z_CBPRINTF_MUST_RUNTIME_PACKAGE'
92 | Z_CBPRINTF_MUST_RUNTIME_PACKAGE(skip, VA_ARGS)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../zephyr/include/logging/log_msg2.h:400:6: note: in expansion of macro 'CBPRINTF_MUST_RUNTIME_PACKAGE'
400 | if (CBPRINTF_MUST_RUNTIME_PACKAGE(_cstr_cnt, VA_ARGS)) {
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../zephyr/include/logging/log_msg2.h:429:3: note: in expansion of macro 'Z_LOG_MSG2_CREATE2'
429 | Z_LOG_MSG2_CREATE2(_try_0cpy, _mode, 1, _domain_id, _source,
| ^~~~~~~~~~~~~~~~~~
../zephyr/include/logging/log_core.h:315:3: note: in expansion of macro 'Z_LOG_MSG2_CREATE'
315 | Z_LOG_MSG2_CREATE(!IS_ENABLED(CONFIG_USERSPACE), _mode,
| ^~~~~~~~~~~~~~~~~
../zephyr/include/logging/log_core.h:330:2: note: in expansion of macro 'Z_LOG2'
330 | Z_LOG2(_level,
| ^~~~~~
../zephyr/include/logging/log.h:71:25: note: in expansion of macro 'Z_LOG'
71 | #define LOG_DBG(...) Z_LOG(LOG_LEVEL_DBG, VA_ARGS)
| ^~~~~
../modules/libcpp/zephyr/global_allocator_overloads.cpp:13:5: note: in expansion of macro 'LOG_DBG'
13 | LOG_DBG("size = %u -> %p", (unsigned)size, ptr);
| ^~~~~~~

Environment (please complete the following information):

• OS: Windows
• Toolchain :gcc version 10.2.1 20201103 (release) (GNU Arm Embedded Toolchain 10-2020-q4-major)
• Commit SHA : SHA-1: a379196

Additional context

[galak]

Maybe the same issue as #34495

[nordic-krch]

Yes, same issue. Fix in #34516

[galak]

Closing this as a duplicate.