[libc-commits] [libc] [libc] Fix a couple issues in <wchar.h> header (PR #164666)

[Alexey Samsonov via libc-commits]

https://github.com/vonosmas created https://github.com/llvm/llvm-project/pull/164666

* Add FILE type declaration, as it should be presented in `<wchar.h>`, as well as in `<stdio.h>`
* Fix argument type in `wcsrtombs` / `wcsnrtombs` function - it should be restrict pointer to `mbstate_t`. Add restrict qualifier to internal implementation as well.

This brings us closer to being able to build libcxx with wide-character support against llvm-libc headers.

>From c29778221707b77f2aad3964b3b42f41ab3d681f Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <vonosmas at gmail.com>
Date: Wed, 22 Oct 2025 17:18:24 +0000
Subject: [PATCH] [libc] Fix a couple issues in <wchar.h> header

---
 libc/include/wchar.yaml       | 11 ++++++-----
 libc/src/wchar/wcsnrtombs.cpp |  2 +-
 libc/src/wchar/wcsnrtombs.h   |  2 +-
 libc/src/wchar/wcsrtombs.cpp  |  2 +-
 libc/src/wchar/wcsrtombs.h    |  2 +-
 5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/libc/include/wchar.yaml b/libc/include/wchar.yaml
index 8178091ab2202..b8a0a748cd3ad 100644
--- a/libc/include/wchar.yaml
+++ b/libc/include/wchar.yaml
@@ -4,6 +4,7 @@ macros:
   - macro_name: NULL
     macro_header: null-macro.h
 types:
+  - type_name: FILE
   - type_name: size_t
   - type_name: wint_t
   - type_name: wchar_t
@@ -104,9 +105,9 @@ functions:
   - name: wmemset
     standards:
       - stdc
-    return_type: wchar_t*
+    return_type: wchar_t *
     arguments:
-      - type: wchar_t*
+      - type: wchar_t *
       - type: wchar_t
       - type: size_t
   - name: wcschr
@@ -246,7 +247,7 @@ functions:
       - type: const wchar_t **__restrict
       - type: size_t
       - type: size_t
-      - type: mbstate_t
+      - type: mbstate_t *__restrict
   - name: wcsrtombs
     standards:
       - stdc
@@ -255,7 +256,7 @@ functions:
       - type: char *__restrict
       - type: const wchar_t **__restrict
       - type: size_t
-      - type: mbstate_t
+      - type: mbstate_t *__restrict
   - name: wcrtomb
     standards:
       - stdc
@@ -299,7 +300,7 @@ functions:
     arguments:
       - type: wchar_t *__restrict
       - type: const wchar_t *__restrict
-      - type: wchar_t** __restrict
+      - type: wchar_t **__restrict
   - name: wcpcpy
     standards:
       - stdc
diff --git a/libc/src/wchar/wcsnrtombs.cpp b/libc/src/wchar/wcsnrtombs.cpp
index 7f25b248a0863..a344c2331b532 100644
--- a/libc/src/wchar/wcsnrtombs.cpp
+++ b/libc/src/wchar/wcsnrtombs.cpp
@@ -22,7 +22,7 @@ namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(size_t, wcsnrtombs,
                    (char *__restrict s, const wchar_t **__restrict pwcs,
-                    size_t nwc, size_t len, mbstate_t *ps)) {
+                    size_t nwc, size_t len, mbstate_t *__restrict ps)) {
   LIBC_CRASH_ON_NULLPTR(pwcs);
   static internal::mbstate internal_mbstate;
   auto result = internal::wcsnrtombs(
diff --git a/libc/src/wchar/wcsnrtombs.h b/libc/src/wchar/wcsnrtombs.h
index bf8add75b2951..2ca42c71e2e9d 100644
--- a/libc/src/wchar/wcsnrtombs.h
+++ b/libc/src/wchar/wcsnrtombs.h
@@ -17,7 +17,7 @@
 namespace LIBC_NAMESPACE_DECL {
 
 size_t wcsnrtombs(char *__restrict s, const wchar_t **__restrict pwcs,
-                  size_t nwc, size_t len, mbstate_t *ps);
+                  size_t nwc, size_t len, mbstate_t *__restrict ps);
 
 } // namespace LIBC_NAMESPACE_DECL
 
diff --git a/libc/src/wchar/wcsrtombs.cpp b/libc/src/wchar/wcsrtombs.cpp
index 9d2508cb81a8c..0167e857128de 100644
--- a/libc/src/wchar/wcsrtombs.cpp
+++ b/libc/src/wchar/wcsrtombs.cpp
@@ -22,7 +22,7 @@ namespace LIBC_NAMESPACE_DECL {
 
 LLVM_LIBC_FUNCTION(size_t, wcsrtombs,
                    (char *__restrict s, const wchar_t **__restrict pwcs,
-                    size_t n, mbstate_t *ps)) {
+                    size_t n, mbstate_t *__restrict ps)) {
   LIBC_CRASH_ON_NULLPTR(pwcs);
   static internal::mbstate internal_mbstate;
   auto result = internal::wcsnrtombs(
diff --git a/libc/src/wchar/wcsrtombs.h b/libc/src/wchar/wcsrtombs.h
index d23573f5b9418..b85e2c6ed740a 100644
--- a/libc/src/wchar/wcsrtombs.h
+++ b/libc/src/wchar/wcsrtombs.h
@@ -17,7 +17,7 @@
 namespace LIBC_NAMESPACE_DECL {
 
 size_t wcsrtombs(char *__restrict s, const wchar_t **__restrict pwcs, size_t n,
-                 mbstate_t *ps);
+                 mbstate_t *__restrict ps);
 
 } // namespace LIBC_NAMESPACE_DECL