From 6311f039b2678f0a1367a88679efb7b2e37949dc Mon Sep 17 00:00:00 2001
From: Uzair Nawaz <uzairnawaz@google.com>
Date: Thu, 12 Jun 2025 17:34:45 +0000
Subject: [PATCH] [libc] Build fixes for widechar characterconverter (#143805)

Build fixes for wchar CharacterConverter class
---
 libc/hdr/CMakeLists.txt                |  2 ++
 libc/hdr/types/CMakeLists.txt          | 22 ++++++++++++++++++++++
 libc/include/llvm-libc-types/char8_t.h |  3 +--
 libc/src/__support/CMakeLists.txt      |  2 ++
 libc/src/__support/wchar/mbstate.h     |  1 +
 libc/src/__support/wchar/utf_ret.h     |  5 ++++-
 6 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/libc/hdr/CMakeLists.txt b/libc/hdr/CMakeLists.txt
index 1e9f59621a8e..052a773a4fce 100644
--- a/libc/hdr/CMakeLists.txt
+++ b/libc/hdr/CMakeLists.txt
@@ -221,6 +221,8 @@ add_proxy_header_library(
 
 add_header_library(wchar_overlay HDRS wchar_overlay.h)
 
+add_header_library(uchar_overlay HDRS uchar_overlay.h)
+
 add_proxy_header_library(
   wchar_macros
   HDRS
diff --git a/libc/hdr/types/CMakeLists.txt b/libc/hdr/types/CMakeLists.txt
index 5f6197c93d44..c88c35700907 100644
--- a/libc/hdr/types/CMakeLists.txt
+++ b/libc/hdr/types/CMakeLists.txt
@@ -1,3 +1,25 @@
+add_proxy_header_library(
+  char8_t 
+  HDRS
+    char8_t.h
+  DEPENDS
+    libc.hdr.uchar_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.char8_t
+    libc.include.uchar
+)
+
+add_proxy_header_library(
+  char32_t 
+  HDRS
+    char32_t.h
+  DEPENDS
+    libc.hdr.uchar_overlay
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.char32_t
+    libc.include.uchar
+)
+
 add_proxy_header_library(
   div_t
   HDRS
diff --git a/libc/include/llvm-libc-types/char8_t.h b/libc/include/llvm-libc-types/char8_t.h
index ddadab1afa21..a343be77d810 100644
--- a/libc/include/llvm-libc-types/char8_t.h
+++ b/libc/include/llvm-libc-types/char8_t.h
@@ -9,8 +9,7 @@
 #ifndef LLVM_LIBC_TYPES_CHAR8_T_H
 #define LLVM_LIBC_TYPES_CHAR8_T_H
 
-#if !defined(__cplusplus) && defined(__STDC_VERSION__) &&                      \
-    __STDC_VERSION__ >= 202311L
+#if !(defined(__cplusplus) && defined(__cpp_char8_t))
 typedef unsigned char char8_t;
 #endif
 
diff --git a/libc/src/__support/CMakeLists.txt b/libc/src/__support/CMakeLists.txt
index 8cf2b0cdcdcc..309cde76370f 100644
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@@ -391,4 +391,6 @@ add_subdirectory(fixed_point)
 
 add_subdirectory(time)
 
+add_subdirectory(wchar)
+
 add_subdirectory(math)
diff --git a/libc/src/__support/wchar/mbstate.h b/libc/src/__support/wchar/mbstate.h
index 72ec72756000..cb8950374de4 100644
--- a/libc/src/__support/wchar/mbstate.h
+++ b/libc/src/__support/wchar/mbstate.h
@@ -10,6 +10,7 @@
 #define LLVM_LIBC_SRC___SUPPORT_MBSTATE_H
 
 #include "hdr/types/char32_t.h"
+#include "src/__support/common.h"
 #include <stdint.h>
 
 namespace LIBC_NAMESPACE_DECL {
diff --git a/libc/src/__support/wchar/utf_ret.h b/libc/src/__support/wchar/utf_ret.h
index b8a8f6f09414..fa99b76159bd 100644
--- a/libc/src/__support/wchar/utf_ret.h
+++ b/libc/src/__support/wchar/utf_ret.h
@@ -9,13 +9,16 @@
 #ifndef LLVM_LIBC_SRC___SUPPORT_UTF_RET_H
 #define LLVM_LIBC_SRC___SUPPORT_UTF_RET_H
 
-namespace LIBC_NAMESPACE_DECL {
+#include "src/__support/common.h"
 
+namespace LIBC_NAMESPACE_DECL {
+namespace internal {
 template <typename T> struct utf_ret {
   T out;
   int error;
 };
 
+} // namespace internal
 } // namespace LIBC_NAMESPACE_DECL
 
 #endif // LLVM_LIBC_SRC___SUPPORT_UTF_RET_H