libc-test: Resolve alias?

[farao]

I'm trying to resolve Warnings of libc-test for a uclibc-based OS (x86_64-unknown-l4re-uclibc). Currently, I'm facing a more general issue for which I'm not sure how to fix it:

1. There is a type alias in the rust files.

Example:

libc/src/unix/linux_like/linux/uclibc/x86_64/mod.rs

Line 11 in e021460

pub type fsword_t = c_long;

Since this is a "helper type" without pendant in the uclibc, I added this to cfg.skip_type(...)

2. There is a struct using this type alias as a field type

Example:

libc/src/unix/linux_like/linux/uclibc/x86_64/mod.rs

Lines 149 to 151 in e021460

	pub struct statfs {
	// FIXME(ulibc)
	pub f_type: fsword_t,

3. Then we have the problem, that the type alias is not resolved

Example:

warning: [email protected]: .../out/main.c:27500:18: error: unknown type name 'fsword_t';
warning: [email protected]: 27500 |                  fsword_t* __test_field_type_statfs_f_type(struct statfs* b) {
warning: [email protected]:       |                  ^~~~~~~~

=> Is there any way how to resolve this problem?

I tried adding the resolving of type aliases to ctest2:

-            s => (self.opts.type_name)(s, self.structs.contains(s), self.unions.contains(s)),
+            s => {
+                let new_s = (self.opts.type_name)(s, self.structs.contains(s), self.unions.contains(s));
+
+                if self.aliases.contains_key(&new_s) {
+                    self.ty2name(self.aliases.get(&new_s).unwrap(), false)
+                } else {
+                    new_s.to_string()
+                }
+            }

at: https://github.com/JohnTitor/ctest2/blob/05634716fbe6f9ea4bf090ce85776269740b1a58/src/lib.rs#L1214

But this brings up new problems, e.g. that types get resolved that were not meant to be resolved, e.g.

pub type Elf32_Rel = __c_anonymous_elf32_rel;

here's the corresponding warning:

   5 warning: [email protected]: .../out/main.c:14500:67: error: invalid application of 'sizeof' to incomplete type 'struct __c_anonymous_elf64_rel'
   6 warning: [email protected]: 14500 |              uint64_t __test_size_Elf32_Rel(void) { return sizeof(struct __c_anonymous_elf64_rel); }

What do you think? Is...

• resolving the alias the correct move and think about a solution for the followup errors?
• or is there an easy solution for the original problem that does not need changes in ctest2?

[tgross35]

Hold off on doing any ctest changes, we'll have that in-repo soon #4283. Does ulibc use this type alias? If our definitions do match libc but ctest is causing problems, then fixing ctest is probably the best way forward.