[libc] Add support for 'string.h' locale variants (#105719)

Summary:
This adds the locale variants of the string functions. As previously,
these do not use the locale information at all and simply copy the
non-locale version which expects the "C" locale.

libc/config/gpu/entrypoints.txt

@@ -58,6 +58,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.string.strchrnul
     libc.src.string.strcmp
     libc.src.string.strcoll
+    libc.src.string.strcoll_l
     libc.src.string.strcpy
     libc.src.string.strcspn
     libc.src.string.strdup
@@ -79,6 +80,7 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.string.strtok
     libc.src.string.strtok_r
     libc.src.string.strxfrm
+    libc.src.string.strxfrm_l
 
     # stdbit.h entrypoints
     libc.src.stdbit.stdc_bit_ceil_uc

libc/config/linux/x86_64/entrypoints.txt

@@ -809,6 +809,10 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdlib.strtoul_l
     libc.src.stdlib.strtoull_l
 
+    # string.h entrypoints
+    libc.src.string.strcoll_l
+    libc.src.string.strxfrm_l
+
     # assert.h entrypoints
     libc.src.assert.__assert_fail
 

libc/include/string.h.def

@@ -11,6 +11,7 @@
 
 #include "__llvm-libc-common.h"
 
+#include "llvm-libc-types/locale_t.h"
 #include "llvm-libc-macros/null-macro.h"
 
 %%public_api()

libc/newhdrgen/yaml/string.yaml

@@ -144,6 +144,14 @@ functions:
     arguments:
       - type: const char *
       - type: const char *
+  - name: strcoll_l
+    standards:
+      - stdc
+    return_type: int
+    arguments:
+      - type: const char *
+      - type: const char *
+      - type: locale_t
   - name: strcpy
     standards:
       - stdc
@@ -300,3 +308,12 @@ functions:
       - type: char *__restrict
       - type: const char *__restrict
       - type: size_t
+  - name: strxfrm_l
+    standards:
+      - stdc
+    return_type: size_t
+    arguments:
+      - type: char *__restrict
+      - type: const char *__restrict
+      - type: size_t
+      - type: locale_t

libc/spec/stdc.td

@@ -354,6 +354,11 @@ def StdC : StandardSpec<"stdc"> {
               RetValSpec<IntType>,
               [ArgSpec<ConstCharPtr>, ArgSpec<ConstCharPtr>]
           >,
+          FunctionSpec<
+              "strcoll_l",
+              RetValSpec<IntType>,
+              [ArgSpec<ConstCharPtr>, ArgSpec<ConstCharPtr>, ArgSpec<LocaleT>]
+          >,
           FunctionSpec<
               "strncmp",
               RetValSpec<IntType>,
@@ -366,6 +371,14 @@ def StdC : StandardSpec<"stdc"> {
                ArgSpec<ConstCharRestrictedPtr>,
                ArgSpec<SizeTType>]
           >,
+          FunctionSpec<
+              "strxfrm_l",
+              RetValSpec<SizeTType>,
+              [ArgSpec<CharRestrictedPtr>,
+               ArgSpec<ConstCharRestrictedPtr>,
+               ArgSpec<SizeTType>,
+               ArgSpec<LocaleT>]
+          >,
           FunctionSpec<
               "strchr",
               RetValSpec<CharPtr>,

libc/src/string/CMakeLists.txt

@@ -200,6 +200,14 @@ add_entrypoint_object(
     strcoll.h
 )
 
+add_entrypoint_object(
+  strcoll_l
+  SRCS
+    strcoll_l.cpp
+  HDRS
+  strcoll_l.h
+)
+
 add_entrypoint_object(
   strcpy
   SRCS
@@ -441,6 +449,17 @@ add_entrypoint_object(
     .memory_utils.inline_memcpy
 )
 
+add_entrypoint_object(
+  strxfrm_l
+  SRCS
+    strxfrm_l.cpp
+  HDRS
+    strxfrm_l.h
+  DEPENDS
+    .string_utils
+    .memory_utils.inline_memcpy
+)
+
 add_entrypoint_object(
   memset_explicit
   SRCS

libc/src/string/strcoll_l.cpp

@@ -0,0 +1,24 @@
+//===-- Implementation of strcoll_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/string/strcoll_l.h"
+
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+// TODO: Add support for locales.
+LLVM_LIBC_FUNCTION(int, strcoll_l,
+                   (const char *left, const char *right, locale_t)) {
+  for (; *left && *left == *right; ++left, ++right)
+    ;
+  return static_cast<int>(*left) - static_cast<int>(*right);
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/string/strcoll_l.h

@@ -0,0 +1,21 @@
+//===-- Implementation header for strcoll_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_STRING_STRCOLL_L_H
+#define LLVM_LIBC_SRC_STRING_STRCOLL_L_H
+
+#include "include/llvm-libc-types/locale_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+int strcoll_l(const char *left, const char *right, locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_STRING_STRCOLL_L_H

libc/src/string/strxfrm_l.cpp

@@ -0,0 +1,28 @@
+//===-- Implementation of strxfrm_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/string/strxfrm_l.h"
+#include "src/__support/macros/config.h"
+#include "src/string/memory_utils/inline_memcpy.h"
+#include "src/string/string_utils.h"
+
+#include "src/__support/common.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+// TODO: Add support for locales.
+LLVM_LIBC_FUNCTION(size_t, strxfrm_l,
+                   (char *__restrict dest, const char *__restrict src, size_t n,
+                    locale_t)) {
+  size_t len = internal::string_length(src);
+  if (n > len)
+    inline_memcpy(dest, src, len + 1);
+  return len;
+}
+
+} // namespace LIBC_NAMESPACE_DECL

libc/src/string/strxfrm_l.h

@@ -0,0 +1,23 @@
+//===-- Implementation header for strxfrm_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_STRING_STRXFRM_L_H
+#define LLVM_LIBC_SRC_STRING_STRXFRM_L_H
+
+#include "include/llvm-libc-types/locale_t.h"
+#include "src/__support/macros/config.h"
+#include <stddef.h> // For size_t
+
+namespace LIBC_NAMESPACE_DECL {
+
+size_t strxfrm_l(char *__restrict dest, const char *__restrict src, size_t n,
+                 locale_t locale);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_STRING_STRXFRM_L_H