[libc] wchar string conversion functions mb to wc

libc/config/linux/x86_64/entrypoints.txt

@@ -1261,6 +1261,9 @@ if(LLVM_LIBC_FULL_BUILD)
     # wchar.h entrypoints
     libc.src.wchar.mbrtowc
     libc.src.wchar.mbtowc
+    libc.src.wchar.mbstowcs
+    libc.src.wchar.mbsrtowcs
+    libc.src.wchar.mbsnrtowcs
     libc.src.wchar.wcrtomb
     libc.src.wchar.wctomb
   )

libc/include/wchar.yaml

@@ -53,6 +53,33 @@ functions:
       - type: wchar_t *__restrict
       - type: const char *__restrict
       - type: size_t
+  - name: mbstowcs
+    standards:
+      - stdc
+    return_type: size_t
+    arguments:
+      - type: wchar_t *__restrict
+      - type: const char *__restrict
+      - type: size_t
+  - name: mbsrtowcs
+    standards:
+      - stdc
+    return_type: size_t
+    arguments:
+      - type: wchar_t *__restrict
+      - type: const char **__restrict
+      - type: size_t
+      - type: mbstate_t *__restrict
+  - name: mbsnrtowcs
+    standards:
+      - stdc
+    return_type: size_t
+    arguments:
+      - type: wchar_t *__restrict
+      - type: const char **__restrict
+      - type: size_t
+      - type: size_t
+      - type: mbstate_t *__restrict
   - name: wmemset
     standards:
       - stdc

libc/src/__support/wchar/CMakeLists.txt

@@ -68,3 +68,21 @@ add_object_library(
   .character_converter
   .mbstate
 )
+
+add_object_library(
+  mbsnrtowcs
+  HDRS
+    mbsnrtowcs.h
+  SRCS
+    mbsnrtowcs.cpp
+  DEPENDS
+  libc.hdr.errno_macros
+  libc.hdr.types.wchar_t
+  libc.hdr.types.size_t
+  libc.src.__support.common
+  libc.src.__support.error_or
+  libc.src.__support.macros.config
+  .character_converter
+  .mbstate
+  .string_converter
+)

libc/src/__support/wchar/mbsnrtowcs.cpp

@@ -0,0 +1,59 @@
+//===-- Implementation for mbsnrtowcs function ------------------*- C++ -*-===//
+//
+// 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 "src/__support/wchar/mbsnrtowcs.h"
+#include "hdr/errno_macros.h"
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/wchar/character_converter.h"
+#include "src/__support/wchar/mbstate.h"
+#include "src/__support/wchar/string_converter.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace internal {
+
+ErrorOr<size_t> mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+                           size_t nmc, size_t len, mbstate *__restrict ps) {
+  if (*src == nullptr)
+    return 0;
+  // Checking if mbstate is valid
+  CharacterConverter char_conv(ps);
+  if (!char_conv.isValidState())
+    return Error(EINVAL);
+
+  StringConverter<char8_t> str_conv(reinterpret_cast<const char8_t *>(*src), ps,
+                                    len, nmc);
+  size_t dst_idx = 0;
+  ErrorOr<char32_t> converted = str_conv.popUTF32();
+  while (converted.has_value()) {
+    if (dst != nullptr)
+      dst[dst_idx] = converted.value();
+    // null terminator should not be counted in return value
+    if (converted.value() == L'\0') {
+      if (dst != nullptr)
+        *src = nullptr;
+      return dst_idx;
+    }
+    dst_idx++;
+    converted = str_conv.popUTF32();
+  }
+
+  if (converted.error() == -1) { // if we hit conversion limit
+    *src += str_conv.getSourceIndex();
+    return dst_idx;
+  }
+
+  return Error(converted.error());
+}
+
+} // namespace internal
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/__support/wchar/mbsnrtowcs.h

@@ -0,0 +1,29 @@
+//===-- Implementation header for mbsnrtowcs function -----------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC___SUPPORT_WCHAR_MBSNRTOWCS
+#define LLVM_LIBC_SRC___SUPPORT_WCHAR_MBSNRTOWCS
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/wchar/mbstate.h"
+
+namespace LIBC_NAMESPACE_DECL {
+namespace internal {
+
+ErrorOr<size_t> mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+                           size_t nmc, size_t len, mbstate *__restrict ps);
+
+} // namespace internal
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC___SUPPORT_WCHAR_MBSNRTOWCS

libc/src/wchar/CMakeLists.txt

@@ -159,6 +159,56 @@ add_entrypoint_object(
     libc.src.__support.wchar.mbstate
 )
 
+add_entrypoint_object(
+  mbstowcs
+  SRCS
+    mbstowcs.cpp
+  HDRS
+    mbstowcs.h
+  DEPENDS
+    libc.hdr.types.size_t
+    libc.hdr.types.wchar_t
+    libc.src.__support.common
+    libc.src.__support.macros.config
+    libc.src.__support.libc_errno
+    libc.src.__support.wchar.mbstate
+    libc.src.__support.wchar.mbsnrtowcs
+)
+
+add_entrypoint_object(
+  mbsrtowcs
+  SRCS
+    mbsrtowcs.cpp
+  HDRS
+    mbsrtowcs.h
+  DEPENDS
+    libc.hdr.types.size_t
+    libc.hdr.types.wchar_t
+    libc.src.__support.common
+    libc.src.__support.macros.config
+    libc.src.__support.libc_errno
+    libc.src.__support.wchar.mbstate
+    libc.src.__support.wchar.mbsnrtowcs
+    libc.src.__support.wchar.mbstate
+)
+
+add_entrypoint_object(
+  mbsnrtowcs
+  SRCS
+    mbsnrtowcs.cpp
+  HDRS
+    mbsnrtowcs.h
+  DEPENDS
+    libc.hdr.types.size_t
+    libc.hdr.types.wchar_t
+    libc.src.__support.common
+    libc.src.__support.macros.config
+    libc.src.__support.libc_errno
+    libc.src.__support.wchar.mbstate
+    libc.src.__support.wchar.mbsnrtowcs
+    libc.src.__support.wchar.mbstate
+)
+
 add_entrypoint_object(
   wmemset
   SRCS

libc/src/wchar/mbsnrtowcs.cpp

@@ -0,0 +1,39 @@
+//===-- Implementation of mbsnrtowcs --------------------------------------===//
+//
+// 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 "src/wchar/mbsnrtowcs.h"
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/wchar/mbsnrtowcs.h"
+#include "src/__support/wchar/mbstate.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(size_t, mbsnrtowcs,
+                   (wchar_t *__restrict dst, const char **__restrict src,
+                    size_t nmc, size_t len, mbstate_t *__restrict ps)) {
+  static internal::mbstate internal_mbstate;
+  // If destination is null, ignore len
+  len = dst == nullptr ? SIZE_MAX : len;
+  auto ret = internal::mbsnrtowcs(
+      dst, src, nmc, len,
+      ps == nullptr ? &internal_mbstate
+                    : reinterpret_cast<internal::mbstate *>(ps));
+  if (!ret.has_value()) {
+    // Encoding failure
+    libc_errno = ret.error();
+    return -1;
+  }
+  return ret.value();
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/wchar/mbsnrtowcs.h

@@ -0,0 +1,24 @@
+//===-- Implementation header for mbsnrtowcs ------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_WCHAR_MBSNRTOWCS_H
+#define LLVM_LIBC_SRC_WCHAR_MBSNRTOWCS_H
+
+#include "hdr/types/mbstate_t.h"
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+size_t mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+                  size_t nmc, size_t len, mbstate_t *__restrict ps);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_MBSNRTOWCS_H

libc/src/wchar/mbsrtowcs.cpp

@@ -0,0 +1,39 @@
+//===-- Implementation of mbsrtowcs ---------------------------------------===//
+//
+// 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 "src/wchar/mbsrtowcs.h"
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/wchar/mbsnrtowcs.h"
+#include "src/__support/wchar/mbstate.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(size_t, mbsrtowcs,
+                   (wchar_t *__restrict dst, const char **__restrict src,
+                    size_t len, mbstate_t *__restrict ps)) {
+  static internal::mbstate internal_mbstate;
+  // If destination is null, ignore len
+  len = dst == nullptr ? SIZE_MAX : len;
+  auto ret = internal::mbsnrtowcs(
+      dst, src, SIZE_MAX, len,
+      ps == nullptr ? &internal_mbstate
+                    : reinterpret_cast<internal::mbstate *>(ps));
+  if (!ret.has_value()) {
+    // Encoding failure
+    libc_errno = ret.error();
+    return -1;
+  }
+  return ret.value();
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/wchar/mbsrtowcs.h

@@ -0,0 +1,24 @@
+//===-- Implementation header for mbsrtowcs -------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_WCHAR_MBSRTOWCS_H
+#define LLVM_LIBC_SRC_WCHAR_MBSRTOWCS_H
+
+#include "hdr/types/mbstate_t.h"
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+size_t mbsrtowcs(wchar_t *__restrict dst, const char **__restrict src,
+                 size_t len, mbstate_t *__restrict ps);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_WCHAR_MBSRTOWCS_H

libc/src/wchar/mbstowcs.cpp

@@ -0,0 +1,38 @@
+//===-- Implementation of mbstowcs ----------------------------------------===//
+//
+// 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 "src/wchar/mbstowcs.h"
+
+#include "hdr/types/size_t.h"
+#include "hdr/types/wchar_t.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+#include "src/__support/macros/config.h"
+#include "src/__support/wchar/mbsnrtowcs.h"
+#include "src/__support/wchar/mbstate.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(size_t, mbstowcs,
+                   (wchar_t *__restrict pwcs, const char *__restrict s,
+                    size_t n)) {
+  // If destination is null, ignore n
+  n = pwcs == nullptr ? SIZE_MAX : n;
+  static internal::mbstate internal_mbstate;
+  const char *temp = s;
+  auto ret = internal::mbsnrtowcs(pwcs, &temp, SIZE_MAX, n, &internal_mbstate);
+
+  if (!ret.has_value()) {
+    // Encoding failure
+    libc_errno = ret.error();
+    return -1;
+  }
+  return ret.value();
+}
+
+} // namespace LIBC_NAMESPACE_DECL