C23-incompatible bool definition and CMake build #1588

What type of issue is this?

permanent - occurring repeatedly

What issue are you facing?

The build system used to explicitly set the C standard to C90 with set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu90") - this was removed in the #1586 changes. This causes build failure with a compiler like GCC 15 that defaults to C23, because several of the source files have non-C23-compatible definitions of bool.

There are two ways to fix this: either specify the C standard explicitly in CMake (it's simpler to do this by setting CMAKE_C_STANDARD), or fix the code to be compatible with newer versions of C (you could require C99 rather than C90 and use stdbool.h, for example).

What are the steps to reproduce this?

Build using CMake's defaults on a machine with GCC 15.

Can you provide any logs? (output, errors, etc.)

You get an error like this for each of the files that has a typedef for bool:

/src/radio/hackrf/work/ab605692553a9e59dd74222f98fa1dda86a5e44e/host/hackrf-tools/src/hackrf_operacake.c:31:13: error: ‘bool’ cannot be defined via ‘typedef’
   31 | typedef int bool;
      |             ^~~~
/src/radio/hackrf/work/ab605692553a9e59dd74222f98fa1dda86a5e44e/host/hackrf-tools/src/hackrf_operacake.c:31:13: note: ‘bool’ is a keyword with ‘-std=c23’ onwards
/src/radio/hackrf/work/ab605692553a9e59dd74222f98fa1dda86a5e44e/host/hackrf-tools/src/hackrf_operacake.c:31:1: warning: useless type name in empty declaration
   31 | typedef int bool;
      | ^~~~~~~