Re: [PATCH net-next] tools: ynl: make ynl.c more c++ friendly
From: Jakub Kicinski <kuba@kernel.org>
Date: 2025-08-14 22:27:08
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On Thu, 14 Aug 2025 09:44:13 -0700 Stanislav Fomichev wrote:
Compiling ynl.c in a C++ code base requires invoking C compiler and using extern "C" for the headers. To make it easier, we can add small changes to the ynl.c file to make it palatable to the native C++ compiler. The changes are: - avoid using void* pointer arithmetic, use char* instead - avoid implicit void* type casts, add c-style explicit casts - avoid implicit int->enum type casts, add c-style explicit casts - avoid anonymous structs (for type casts) - namespacify cpp version, this should let us compile both ynl.c as c and ynl.c as cpp in the same binary (YNL_CPP can be used to enable/disable namespacing) Also add test_cpp rule to make sure ynl.c won't break C++ in the future.
As I mentioned in person, ynl-cpp is a separate thing, and you'd all benefit from making it more C++ than going the other way and massaging YNL C. With that said, commenting below on the few that I think would be okay.
quoted hunk ↗ jump to hunk
@@ -224,7 +228,7 @@ static inline void *ynl_attr_data_end(const struct nlattr *attr) #define ynl_attr_for_each_payload(start, len, attr) \ for ((attr) = ynl_attr_first(start, len, 0); attr; \ - (attr) = ynl_attr_next(start + len, attr)) + (attr) = ynl_attr_next((char *)start + len, attr))
okay
quoted hunk ↗ jump to hunk
@@ -149,7 +153,7 @@ ynl_err_walk(struct ynl_sock *ys, void *start, void *end, unsigned int off, return n; } - data_len = end - start; + data_len = (char *)end - (char *)start;
can we make the arguments char * instead of the casts?
static void ynl_err_reset(struct ynl_sock *ys)
{
- ys->err.code = 0;
+ ys->err.code = YNL_ERROR_NONE;sure
quoted hunk ↗ jump to hunk
@@ -56,6 +60,11 @@ struct ynl_family { unsigned int ntf_info_size; }; +struct ynl_sock_mcast {
struct ynl_mcast_grp
+ unsigned int id; + char name[GENL_NAMSIZ]; +};