diff --git a/libc/src/ctype/CMakeLists.txt b/libc/src/ctype/CMakeLists.txt
@@ -146,3 +146,159 @@ add_entrypoint_object(
   DEPENDS
     libc.src.__support.ctype_utils
 )
+
+# Do not build the locale versions in overlay mode.
+if(NOT LLVM_LIBC_FULL_BUILD)
+  return()
+endif()
+
+add_entrypoint_object(
+  isalnum_l
+  SRCS
+    isalnum_l.cpp
+  HDRS
+    isalnum_l.h
+  DEPENDS
+    libc.include.ctype
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isalpha_l
+  SRCS
+    isalpha_l.cpp
+  HDRS
+    isalpha_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isblank_l
+  SRCS
+    isblank_l.cpp
+  HDRS
+    isblank_l.h
+  DEPENDS
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  iscntrl_l
+  SRCS
+    iscntrl_l.cpp
+  HDRS
+    iscntrl_l.h
+  DEPENDS
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isdigit_l
+  SRCS
+    isdigit_l.cpp
+  HDRS
+    isdigit_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isgraph_l
+  SRCS
+    isgraph_l.cpp
+  HDRS
+    isgraph_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  islower_l
+  SRCS
+    islower_l.cpp
+  HDRS
+    islower_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isprint_l
+  SRCS
+    isprint_l.cpp
+  HDRS
+    isprint_l.h
+  DEPENDS
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  ispunct_l
+  SRCS
+    ispunct_l.cpp
+  HDRS
+    ispunct_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isspace_l
+  SRCS
+    isspace_l.cpp
+  HDRS
+    isspace_l.h
+  DEPENDS
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isupper_l
+  SRCS
+    isupper_l.cpp
+  HDRS
+    isupper_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  isxdigit_l
+  SRCS
+    isxdigit_l.cpp
+  HDRS
+    isxdigit_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  tolower_l
+  SRCS
+    tolower_l.cpp
+  HDRS
+    tolower_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
+
+add_entrypoint_object(
+  toupper_l
+  SRCS
+    toupper_l.cpp
+  HDRS
+    toupper_l.h
+  DEPENDS
+    libc.src.__support.ctype_utils
+    libc.hdr.types.locale_t
+)
diff --git a/libc/src/ctype/isalnum.cpp b/libc/src/ctype/isalnum.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isalnum, (int c)) {
   return static_cast<int>(internal::isalnum(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isalnum_l.cpp b/libc/src/ctype/isalnum_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of isalnum -----------------------------------------===//
+//
+// 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/ctype/isalnum_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isalnum_l, (int c, locale_t)) {
+  return static_cast<int>(internal::isalnum(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isalnum_l.h b/libc/src/ctype/isalnum_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isalnum_l -----------------------*-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_CTYPE_ISALNUM_H
+#define LLVM_LIBC_SRC_CTYPE_ISALNUM_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isalnum_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISALNUM_H
diff --git a/libc/src/ctype/isalpha.cpp b/libc/src/ctype/isalpha.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isalpha, (int c)) {
   return static_cast<int>(internal::isalpha(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isalpha_l.cpp b/libc/src/ctype/isalpha_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of isalpha -----------------------------------------===//
+//
+// 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/ctype/isalpha_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/ctype_utils.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isalpha_l, (int c, locale_t)) {
+  return static_cast<int>(internal::isalpha(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isalpha_l.h b/libc/src/ctype/isalpha_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isalpha_l -----------------------*-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_CTYPE_ISALPHA_H
+#define LLVM_LIBC_SRC_CTYPE_ISALPHA_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isalpha_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISALPHA_H
diff --git a/libc/src/ctype/isblank.cpp b/libc/src/ctype/isblank.cpp
@@ -13,8 +13,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isblank, (int c)) {
   return static_cast<int>(c == ' ' || c == '\t');
 }

diff --git a/libc/src/ctype/isblank_l.cpp b/libc/src/ctype/isblank_l.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of isblank -----------------------------------------===//
+//
+// 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/ctype/isblank_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isblank_l, (int c, locale_t)) {
+  return static_cast<int>(c == ' ' || c == '\t');
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isblank_l.h b/libc/src/ctype/isblank_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isblank_l -----------------------*-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_CTYPE_ISBLANK_H
+#define LLVM_LIBC_SRC_CTYPE_ISBLANK_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isblank_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISBLANK_H
diff --git a/libc/src/ctype/iscntrl.cpp b/libc/src/ctype/iscntrl.cpp
@@ -13,8 +13,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, iscntrl, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(ch < 0x20 || ch == 0x7f);

diff --git a/libc/src/ctype/iscntrl_l.cpp b/libc/src/ctype/iscntrl_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of iscntrl -----------------------------------------===//
+//
+// 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/ctype/iscntrl_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, iscntrl_l, (int c, locale_t)) {
+  const unsigned ch = static_cast<unsigned>(c);
+  return static_cast<int>(ch < 0x20 || ch == 0x7f);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/iscntrl_l.h b/libc/src/ctype/iscntrl_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for iscntrl_l -----------------------*-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_CTYPE_ISCNTRL_H
+#define LLVM_LIBC_SRC_CTYPE_ISCNTRL_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int iscntrl_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISCNTRL_H
diff --git a/libc/src/ctype/isdigit.cpp b/libc/src/ctype/isdigit.cpp
@@ -13,8 +13,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isdigit, (int c)) {
   return static_cast<int>(internal::isdigit(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isdigit_l.cpp b/libc/src/ctype/isdigit_l.cpp
@@ -0,0 +1,20 @@
+//===-- Implementation of isdigit -----------------------------------------===//
+//
+// 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/ctype/isdigit_l.h"
+#include "src/__support/common.h"
+#include "src/__support/ctype_utils.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isdigit_l, (int c, locale_t)) {
+  return static_cast<int>(internal::isdigit(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isdigit_l.h b/libc/src/ctype/isdigit_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isdigit_l -----------------------*-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_CTYPE_ISDIGIT_H
+#define LLVM_LIBC_SRC_CTYPE_ISDIGIT_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isdigit_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISDIGIT_H
diff --git a/libc/src/ctype/isgraph.cpp b/libc/src/ctype/isgraph.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isgraph, (int c)) {
   return static_cast<int>(internal::isgraph(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isgraph_l.cpp b/libc/src/ctype/isgraph_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of isgraph -----------------------------------------===//
+//
+// 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/ctype/isgraph_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/ctype_utils.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isgraph_l, (int c, locale_t)) {
+  return static_cast<int>(internal::isgraph(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isgraph_l.h b/libc/src/ctype/isgraph_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isgraph_l -----------------------*-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_CTYPE_ISGRAPH_H
+#define LLVM_LIBC_SRC_CTYPE_ISGRAPH_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isgraph_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISGRAPH_H
diff --git a/libc/src/ctype/islower.cpp b/libc/src/ctype/islower.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, islower, (int c)) {
   return static_cast<int>(internal::islower(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/islower_l.cpp b/libc/src/ctype/islower_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of islower -----------------------------------------===//
+//
+// 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/ctype/islower_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, islower_l, (int c, locale_t)) {
+  return static_cast<int>(internal::islower(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/islower_l.h b/libc/src/ctype/islower_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for islower_l -----------------------*-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_CTYPE_ISLOWER_H
+#define LLVM_LIBC_SRC_CTYPE_ISLOWER_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int islower_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISLOWER_H
diff --git a/libc/src/ctype/isprint.cpp b/libc/src/ctype/isprint.cpp
@@ -13,8 +13,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isprint, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>((ch - ' ') < 95);

diff --git a/libc/src/ctype/isprint_l.cpp b/libc/src/ctype/isprint_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of isprint -----------------------------------------===//
+//
+// 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/ctype/isprint_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isprint_l, (int c, locale_t)) {
+  const unsigned ch = static_cast<unsigned>(c);
+  return static_cast<int>((ch - ' ') < 95);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isprint_l.h b/libc/src/ctype/isprint_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isprint_l -----------------------*-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_CTYPE_ISPRINT_H
+#define LLVM_LIBC_SRC_CTYPE_ISPRINT_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isprint_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISPRINT_H
diff --git a/libc/src/ctype/ispunct.cpp b/libc/src/ctype/ispunct.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, ispunct, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(!internal::isalnum(ch) && internal::isgraph(ch));

diff --git a/libc/src/ctype/ispunct_l.cpp b/libc/src/ctype/ispunct_l.cpp
@@ -0,0 +1,22 @@
+//===-- Implementation of ispunct -----------------------------------------===//
+//
+// 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/ctype/ispunct_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/ctype_utils.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, ispunct_l, (int c, locale_t)) {
+  const unsigned ch = static_cast<unsigned>(c);
+  return static_cast<int>(!internal::isalnum(ch) && internal::isgraph(ch));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/ispunct_l.h b/libc/src/ctype/ispunct_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for ispunct_l -----------------------*-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_CTYPE_ISPUNCT_H
+#define LLVM_LIBC_SRC_CTYPE_ISPUNCT_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int ispunct_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISPUNCT_H
diff --git a/libc/src/ctype/isspace.cpp b/libc/src/ctype/isspace.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isspace, (int c)) {
   return static_cast<int>(internal::isspace(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isspace_l.cpp b/libc/src/ctype/isspace_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of isspace -----------------------------------------===//
+//
+// 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/ctype/isspace_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isspace_l, (int c, locale_t)) {
+  return static_cast<int>(internal::isspace(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isspace_l.h b/libc/src/ctype/isspace_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isspace_l -----------------------*-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_CTYPE_ISSPACE_H
+#define LLVM_LIBC_SRC_CTYPE_ISSPACE_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isspace_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISSPACE_H
diff --git a/libc/src/ctype/isupper.cpp b/libc/src/ctype/isupper.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isupper, (int c)) {
   return static_cast<int>(internal::isupper(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isupper_l.cpp b/libc/src/ctype/isupper_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of isupper -----------------------------------------===//
+//
+// 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/ctype/isupper_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isupper_l, (int c, locale_t)) {
+  return static_cast<int>(internal::isupper(static_cast<unsigned>(c)));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isupper_l.h b/libc/src/ctype/isupper_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isupper_l -----------------------*-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_CTYPE_ISUPPER_H
+#define LLVM_LIBC_SRC_CTYPE_ISUPPER_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isupper_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISUPPER_H
diff --git a/libc/src/ctype/isxdigit.cpp b/libc/src/ctype/isxdigit.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isxdigit, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(internal::isdigit(ch) || (ch | 32) - 'a' < 6);

diff --git a/libc/src/ctype/isxdigit_l.cpp b/libc/src/ctype/isxdigit_l.cpp
@@ -0,0 +1,22 @@
+//===-- Implementation of isxdigit ----------------------------------------===//
+//
+// 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/ctype/isxdigit_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, isxdigit_l, (int c, locale_t)) {
+  const unsigned ch = static_cast<unsigned>(c);
+  return static_cast<int>(internal::isdigit(ch) || (ch | 32) - 'a' < 6);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/isxdigit_l.h b/libc/src/ctype/isxdigit_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for isxdigit_l ----------------------*-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_CTYPE_ISXDIGIT_H
+#define LLVM_LIBC_SRC_CTYPE_ISXDIGIT_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int isxdigit_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_ISXDIGIT_H
diff --git a/libc/src/ctype/tolower.cpp b/libc/src/ctype/tolower.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, tolower, (int c)) { return internal::tolower(c); }
 
 } // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/tolower_l.cpp b/libc/src/ctype/tolower_l.cpp
@@ -0,0 +1,21 @@
+//===-- Implementation of tolower -----------------------------------------===//
+//
+// 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/ctype/tolower_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, tolower_l, (int c, locale_t)) {
+  return internal::tolower(c);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/tolower_l.h b/libc/src/ctype/tolower_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for tolower_l -----------------------*-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_CTYPE_TOLOWER_H
+#define LLVM_LIBC_SRC_CTYPE_TOLOWER_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int tolower_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_TOLOWER_H
diff --git a/libc/src/ctype/toupper.cpp b/libc/src/ctype/toupper.cpp
@@ -14,8 +14,6 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
-// TODO: Currently restricted to default locale.
-// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, toupper, (int c)) {
   if (internal::islower(c))
     return c - ('a' - 'A');

diff --git a/libc/src/ctype/toupper_l.cpp b/libc/src/ctype/toupper_l.cpp
@@ -0,0 +1,23 @@
+//===-- Implementation of toupper_l ---------------------------------------===//
+//
+// 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/ctype/toupper_l.h"
+#include "src/__support/ctype_utils.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, toupper_l, (int c, locale_t)) {
+  if (internal::islower(c))
+    return c - ('a' - 'A');
+  return c;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/toupper_l.h b/libc/src/ctype/toupper_l.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for toupper_l -----------------------*-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_CTYPE_TOUPPER_H
+#define LLVM_LIBC_SRC_CTYPE_TOUPPER_H
+
+#include "hdr/types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int toupper_l(int c, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif //  LLVM_LIBC_SRC_CTYPE_TOUPPER_H