Use 'constexpr' when including pio header files from a C++ compiler #2651

2025-09-06T09:26:18-05:00

rhulme commented

2025-09-06 09:26:18 -05:00

(Migrated from github.com)

In particular this allows compile-time checks to be performed on the contents of pio_program structs via 'static_assert'.

This could be used (for example) to confirm that multiple PIO programs fit in a single PIO module and abort compilation if not.

Fixes #2650

In particular this allows compile-time checks to be performed on the contents of pio_program structs via 'static_assert'. This could be used (for example) to confirm that multiple PIO programs fit in a single PIO module and abort compilation if not. Fixes #2650

lurch (Migrated from github.com) reviewed

2025-09-08 06:53:59 -05:00

tools/pioasm/c_sdk_output.cpp

					
				@ -79,6 +79,13 @@ struct c_sdk_output : public output_format {

				        fprintf(out, "#endif\n");

https://en.cppreference.com/w/cpp/language/constexpr.html says that constexpr was only added in C++11, so should this line perhaps be

        fprintf(out, "#if defined(__cplusplus) && defined(__cpp_constexpr)\n");

so that it doesn't break older C++ compilers? (Or perhaps simply #ifdef __cpp_constexpr is sufficient?)

https://en.cppreference.com/w/cpp/language/constexpr.html says that `constexpr` was only added in C++11, so should this line perhaps be ```suggestion fprintf(out, "#if defined(__cplusplus) && defined(__cpp_constexpr)\n"); ``` so that it doesn't break older C++ compilers? (Or perhaps simply `#ifdef __cpp_constexpr` is sufficient?)

				`@ -79,6 +79,13 @@ struct c_sdk_output : public output_format {`
				`fprintf(out, "#endif\n");`

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