While building, bpftool makes a skeleton from test_core_extern.c, which itself includes <stdbool.h> and uses the 'bool' type. However, the skeleton test_core_extern.skel.h generated *does not* include <stdbool.h> or use the 'bool' type, instead using the C-only '_Bool' type. Compiling test_cpp.cpp with g++ 12.3 for mips64el/musl-libc then fails with error: In file included from test_cpp.cpp:9: test_core_extern.skel.h:45:17: error: '_Bool' does not name a type 45 | _Bool CONFIG_BOOL; | ^~~~~ This was likely missed previously because glibc uses a GNU extension for <stdbool.h> with C++ (#define _Bool bool), not supported by musl libc. Normally, a C fragment would include <stdbool.h> and use the 'bool' type, and thus cleanly work after import by C++. The ideal fix would be for 'bpftool gen skeleton' to output the correct type/include supporting C++, but in the meantime add a conditional define as above.
Unified · Split
| @@ -6,6 +6,10 @@ · 5 unmodified lines | |||
| 6 | #include <bpf/libbpf.h> | 6 | #include <bpf/libbpf.h> |
| 7 | #include <bpf/bpf.h> | 7 | #include <bpf/bpf.h> |
| 8 | #include <bpf/btf.h> | 8 | #include <bpf/btf.h> |
| 9 | |||
| 10 | #ifndef _Bool | ||
| 11 | #define _Bool bool | ||
| 12 | #endif | ||
| 9 | #include "test_core_extern.skel.h" | 13 | #include "test_core_extern.skel.h" |
| 10 | #include "struct_ops_module.skel.h" | 14 | #include "struct_ops_module.skel.h" |
| 11 | 15 | ||