LibC: Implement {f,}putwc()

Userland/Libraries/LibC/bits/stdio_file_implementation.h

@@ -70,7 +70,7 @@ private:
         void realize(int fd);
         void drop();
 
-        bool may_use() const { return m_ungotten || m_mode != _IONBF; }
+        bool may_use() const;
         bool is_not_empty() const { return m_ungotten || !m_empty; }
         size_t buffered_size() const;
 

Userland/Libraries/LibC/stdio.cpp

@@ -341,6 +341,11 @@ FILE::Buffer::~Buffer()
         free(m_data);
 }
 
+bool FILE::Buffer::may_use() const
+{
+    return m_ungotten || m_mode != _IONBF;
+}
+
 void FILE::Buffer::realize(int fd)
 {
     if (m_mode == -1)

Userland/Libraries/LibC/wchar.h

@@ -74,5 +74,8 @@ size_t wcsspn(const wchar_t* wcs, const wchar_t* accept);
 wint_t fgetwc(FILE* stream);
 wint_t getwc(FILE* stream);
 wint_t getwchar(void);
+wint_t fputwc(wchar_t wc, FILE* stream);
+wint_t putwc(wchar_t wc, FILE* stream);
+wint_t putwchar(wchar_t wc);
 
 __END_DECLS

Userland/Libraries/LibC/wstdio.cpp

@@ -5,6 +5,7 @@
  */
 
 #include <AK/Assertions.h>
+#include <AK/BitCast.h>
 #include <AK/StringBuilder.h>
 #include <AK/Types.h>
 #include <bits/stdio_file_implementation.h>
@@ -61,4 +62,34 @@ wint_t getwchar()
 {
     return getwc(stdin);
 }
+
+wint_t fputwc(wchar_t wc, FILE* stream)
+{
+    VERIFY(stream);
+    // Negative wide chars are weird
+    if constexpr (IsSigned<wchar_t>) {
+        if (wc < 0) {
+            errno = EILSEQ;
+            return WEOF;
+        }
+    }
+    StringBuilder sb;
+    sb.append_code_point(static_cast<u32>(wc));
+    auto bytes = sb.string_view().bytes();
+    ScopedFileLock lock(stream);
+    size_t nwritten = stream->write(bytes.data(), bytes.size());
+    if (nwritten < bytes.size())
+        return WEOF;
+    return wc;
+}
+
+wint_t putwc(wchar_t wc, FILE* stream)
+{
+    return fputwc(wc, stream);
+}
+
+wint_t putwchar(wchar_t wc)
+{
+    return fputwc(wc, stdout);
+}
 }