[libcxx-commits] [libcxx] [libc++][modules] Support using the module std with -fno-char8_t. (PR #79155)

[via libcxx-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Po-yao Chang (poyaoc97)

<details>
<summary>Changes</summary>

Exclude some using-declarations in the module purview when compiling with `-fno-char8_t`.

---
Full diff: https://github.com/llvm/llvm-project/pull/79155.diff


4 Files Affected:

- (modified) libcxx/modules/std/atomic.inc (+2) 
- (modified) libcxx/modules/std/iosfwd.inc (+2) 
- (modified) libcxx/modules/std/string.inc (+4) 
- (modified) libcxx/modules/std/string_view.inc (+2) 


``````````diff
diff --git a/libcxx/modules/std/atomic.inc b/libcxx/modules/std/atomic.inc
index 5139b7531093d7a..88b31ccdb208409 100644
--- a/libcxx/modules/std/atomic.inc
+++ b/libcxx/modules/std/atomic.inc
@@ -60,7 +60,9 @@ export namespace std {
   using std::atomic_char;
   using std::atomic_char16_t;
   using std::atomic_char32_t;
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
   using std::atomic_char8_t;
+#endif
   using std::atomic_int;
   using std::atomic_llong;
   using std::atomic_long;
diff --git a/libcxx/modules/std/iosfwd.inc b/libcxx/modules/std/iosfwd.inc
index ec8b434ca0c51b7..410fb6aefed8015 100644
--- a/libcxx/modules/std/iosfwd.inc
+++ b/libcxx/modules/std/iosfwd.inc
@@ -14,7 +14,9 @@ export namespace std {
 #endif
   using std::u16streampos;
   using std::u32streampos;
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
   using std::u8streampos;
+#endif
 
   using std::basic_osyncstream;
   using std::basic_syncbuf;
diff --git a/libcxx/modules/std/string.inc b/libcxx/modules/std/string.inc
index c83ee7643f87e9a..9808a96215a1829 100644
--- a/libcxx/modules/std/string.inc
+++ b/libcxx/modules/std/string.inc
@@ -34,7 +34,9 @@ export namespace std {
   using std::string;
   using std::u16string;
   using std::u32string;
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
   using std::u8string;
+#endif
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
   using std::wstring;
 #endif
@@ -58,7 +60,9 @@ export namespace std {
     using std::pmr::string;
     using std::pmr::u16string;
     using std::pmr::u32string;
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
     using std::pmr::u8string;
+#endif
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
     using std::pmr::wstring;
 #endif
diff --git a/libcxx/modules/std/string_view.inc b/libcxx/modules/std/string_view.inc
index 1fa63a77395358a..f4f9d80ddb83da5 100644
--- a/libcxx/modules/std/string_view.inc
+++ b/libcxx/modules/std/string_view.inc
@@ -27,7 +27,9 @@ export namespace std {
   using std::string_view;
   using std::u16string_view;
   using std::u32string_view;
+#ifndef _LIBCPP_HAS_NO_CHAR8_T
   using std::u8string_view;
+#endif
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
   using std::wstring_view;
 #endif

``````````

</details>


https://github.com/llvm/llvm-project/pull/79155