[cpp] for C code, query variable does not extract all variables (mostly const variable and not ram variable)

I have a database biuld with gcc or clang.
In my C code which compiles I want to extract all variables defined in my project.

I get all const variable but nothing concerning static variable or gllobal variable defined in compiled source.

doxygen is able to extract these variables

No source files, query names, or tests are identified. Reproduce the report with a C database built by GCC or Clang, inspect the variable-extraction query, and compare its results for const, static, global, and non-RAM variables against the project’s definitions; done means all intended variables are reported.

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