[libc++][test] Avoid some transitive includes in standard headers

[frederick-vs-ja]

... for mangled_names.pass.cpp

Some builds of this test file seem failing due to not finding std::errc. Also removes includes of <iostream> and <string_view> as they're unused.

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: A. Jiang (frederick-vs-ja)

Changes

... for mangled_names.pass.cpp

Some builds of this test file seem failing due to not finding std::errc. Also removes includes of <iostream> and <string_view> as they're unused.

---

Full diff: https://github.com/llvm/llvm-project/pull/145846.diff

1 Files Affected:

• (modified) libcxx/test/libcxx/mangled_names.pass.cpp (+3-2)

diff --git a/libcxx/test/libcxx/mangled_names.pass.cpp b/libcxx/test/libcxx/mangled_names.pass.cpp
index 210c40809781e..6ea8465d870c8 100644
--- a/libcxx/test/libcxx/mangled_names.pass.cpp
+++ b/libcxx/test/libcxx/mangled_names.pass.cpp
@@ -15,11 +15,12 @@
 
 #include <cassert>
 #include <charconv>
-#include <iostream>
+#include <cstddef>
 #include <map>
 #include <typeinfo>
 #include <string>
-#include <string_view>
+#include <system_error>
+#include <utility>
 
 template <class>
 struct mangling {};

[philnik777]

I'm pretty sure errc should be provided via <charconv>.

[frederick-vs-ja]

I'm pretty sure errc should be provided via <charconv>.

Yes. But it seems that relying on transitive inclusion is sometimes problematic, as least in CI.

See

• https://github.com/llvm/llvm-project/actions/runs/15888063616/job/44819278583?pr=144249

[philnik777]

I'm pretty sure errc should be provided via <charconv>.

Yes. But it seems that relying on transitive inclusion is sometimes problematic, as least in CI.

See

* https://github.com/llvm/llvm-project/actions/runs/15888063616/job/44819278583?pr=144249

That is a problem with the implementation, not the tests. We shouldn't "fix" that by changing our tests. To me this looks like our modulemap is missing an export.