intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 93 insertions, 0 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/src/support/ibm/wcsnrtombs.cpp b/contrib/libs/cxxsupp/libcxx/src/support/ibm/wcsnrtombs.cpp
new file mode 100644
index 00000000000..01c6241dc54
--- /dev/null
+++ b/contrib/libs/cxxsupp/libcxx/src/support/ibm/wcsnrtombs.cpp
@@ -0,0 +1,93 @@
+//===----------------------- wcsnrtombs.cpp -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include <cwchar>  // mbstate_t
+#include <limits.h> // MB_LEN_MAX
+#include <stdlib.h> // MB_CUR_MAX, size_t
+#include <string.h> // memcpy
+
+// Converts `max_source_chars` from the wide character buffer pointer to by *`src`,
+// into the multi byte character sequence buffer stored at `dst`, which must be
+// `dst_size_bytes` bytes in size. Returns the number of bytes in the sequence
+// converted from *src, excluding the null terminator.
+// Returns (size_t) -1 if an error occurs and sets errno.
+// If `dst` is NULL, `dst_size_bytes` is ignored and no bytes are copied to `dst`.
+_LIBCPP_FUNC_VIS
+size_t wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
+                   size_t max_source_chars, size_t dst_size_bytes,
+                   mbstate_t *__restrict ps) {
+
+  const size_t invalid_wchar = static_cast<size_t>(-1);
+
+  size_t source_converted;
+  size_t dest_converted;
+  size_t result = 0;
+
+  // If `dst` is null then `dst_size_bytes` should be ignored according to the
+  // standard. Setting dst_size_bytes to a large value has this effect.
+  if (dst == nullptr)
+    dst_size_bytes = static_cast<size_t>(-1);
+
+  for (dest_converted = source_converted = 0;
+       source_converted < max_source_chars && (!dst || dest_converted < dst_size_bytes);
+       ++source_converted, dest_converted += result) {
+    wchar_t c = (*src)[source_converted];
+    size_t dest_remaining = dst_size_bytes - dest_converted;
+
+    if (dst == nullptr) {
+      result = wcrtomb(NULL, c, ps);
+    } else if (dest_remaining >= static_cast<size_t>(MB_CUR_MAX)) {
+      // dst has enough space to translate in-place.
+      result = wcrtomb(dst + dest_converted, c, ps);
+    } else {
+      /*
+      * dst may not have enough space, so use a temporary buffer.
+      *
+      * We need to save a copy of the conversion state
+      * here so we can restore it if the multibyte
+      * character is too long for the buffer.
+      */
+      char buff[MB_LEN_MAX];
+      mbstate_t mbstate_tmp;
+
+      if (ps != nullptr)
+        mbstate_tmp = *ps;
+      result = wcrtomb(buff, c, ps);
+
+      if (result > dest_remaining) {
+        // Multi-byte sequence for character won't fit.
+        if (ps != nullptr)
+          *ps = mbstate_tmp;
+        if (result != invalid_wchar)
+          break;
+      } else {
+        // The buffer was used, so we need copy the translation to dst.
+        memcpy(dst, buff, result);
+      }
+    }
+
+    // result (char_size) contains the size of the multi-byte-sequence converted.
+    // Otherwise, result (char_size) is (size_t) -1 and wcrtomb() sets the errno.
+    if (result == invalid_wchar) {
+      if (dst)
+        *src = *src + source_converted;
+      return invalid_wchar;
+    }
+
+    if (c == L'\0') {
+      if (dst)
+        *src = NULL;
+      return dest_converted;
+    }
+  }
+
+  if (dst)
+    *src = *src + source_converted;
+
+  return dest_converted;
+}