[libc-commits] [libc] [libc] Changed CharacterConverter returns (PR #146130)

[via libc-commits]

https://github.com/sribee8 updated https://github.com/llvm/llvm-project/pull/146130

>From 3e647eb794c57d6029cbf9a81d72b76f61accb79 Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Fri, 27 Jun 2025 18:15:33 +0000
Subject: [PATCH 1/2] [libc] Changed CharacterConverter returns

changed internal CharacterConverter returns to return errno macro when necessary for consistency.
---
 libc/src/__support/wchar/CMakeLists.txt          | 1 +
 libc/src/__support/wchar/character_converter.cpp | 7 ++++---
 libc/src/__support/wchar/mbrtowc.cpp             | 4 ++--
 libc/src/__support/wchar/wcrtomb.cpp             | 5 +----
 4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/libc/src/__support/wchar/CMakeLists.txt b/libc/src/__support/wchar/CMakeLists.txt
index 86a47319f278a..d3fb58ed0c71c 100644
--- a/libc/src/__support/wchar/CMakeLists.txt
+++ b/libc/src/__support/wchar/CMakeLists.txt
@@ -13,6 +13,7 @@ add_object_library(
   SRCS 
     character_converter.cpp
   DEPENDS
+    libc.hdr.errno_macros
     libc.hdr.types.char8_t
     libc.hdr.types.char32_t
     libc.src.__support.error_or
diff --git a/libc/src/__support/wchar/character_converter.cpp b/libc/src/__support/wchar/character_converter.cpp
index c54a1b751f402..3cacfa5689e4d 100644
--- a/libc/src/__support/wchar/character_converter.cpp
+++ b/libc/src/__support/wchar/character_converter.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "hdr/errno_macros.h"
 #include "hdr/types/char32_t.h"
 #include "hdr/types/char8_t.h"
 #include "src/__support/CPP/bit.h"
@@ -76,7 +77,7 @@ int CharacterConverter::push(char8_t utf8_byte) {
     else {
       // bytes_stored and total_bytes will always be 0 here
       state->partial = static_cast<char32_t>(0);
-      return -1;
+      return EILSEQ;
     }
     state->partial = static_cast<char32_t>(utf8_byte);
     state->bytes_stored++;
@@ -93,7 +94,7 @@ int CharacterConverter::push(char8_t utf8_byte) {
   }
   // Invalid byte -> reset the state
   clear();
-  return -1;
+  return EILSEQ;
 }
 
 int CharacterConverter::push(char32_t utf32) {
@@ -115,7 +116,7 @@ int CharacterConverter::push(char32_t utf32) {
   // `utf32` contains a value that is too large to actually represent a valid
   // unicode character
   clear();
-  return -1;
+  return EILSEQ;
 }
 
 ErrorOr<char32_t> CharacterConverter::pop_utf32() {
diff --git a/libc/src/__support/wchar/mbrtowc.cpp b/libc/src/__support/wchar/mbrtowc.cpp
index 3b8f7666026c3..90ba934c42b69 100644
--- a/libc/src/__support/wchar/mbrtowc.cpp
+++ b/libc/src/__support/wchar/mbrtowc.cpp
@@ -32,8 +32,8 @@ ErrorOr<size_t> mbrtowc(wchar_t *__restrict pwc, const char *__restrict s,
   for (; i < n && !char_conv.isFull(); ++i) {
     int err = char_conv.push(static_cast<char8_t>(s[i]));
     // Encoding error
-    if (err == -1)
-      return Error(EILSEQ);
+    if (err == EILSEQ)
+      return Error(err);
   }
   auto wc = char_conv.pop_utf32();
   if (wc.has_value()) {
diff --git a/libc/src/__support/wchar/wcrtomb.cpp b/libc/src/__support/wchar/wcrtomb.cpp
index a74a6f3ec34a6..fc54bbfc93e0c 100644
--- a/libc/src/__support/wchar/wcrtomb.cpp
+++ b/libc/src/__support/wchar/wcrtomb.cpp
@@ -30,12 +30,9 @@ ErrorOr<size_t> wcrtomb(char *__restrict s, wchar_t wc,
   if (!cr.isValidState())
     return Error(EINVAL);
 
-  if (s == nullptr)
-    return Error(EILSEQ);
-
   int status = cr.push(static_cast<char32_t>(wc));
   if (status != 0)
-    return Error(EILSEQ);
+    return Error(status);
 
   size_t count = 0;
   while (!cr.isEmpty()) {

>From 3e6fa7fc1699f9fc3a04eb2d2649227e6da0460d Mon Sep 17 00:00:00 2001
From: Sriya Pratipati <sriyap at google.com>
Date: Fri, 27 Jun 2025 20:11:18 +0000
Subject: [PATCH 2/2] updated test file with correct error values

---
 libc/test/src/__support/wchar/utf8_to_32_test.cpp | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/libc/test/src/__support/wchar/utf8_to_32_test.cpp b/libc/test/src/__support/wchar/utf8_to_32_test.cpp
index 36ae7d689cc00..b419fb5d55414 100644
--- a/libc/test/src/__support/wchar/utf8_to_32_test.cpp
+++ b/libc/test/src/__support/wchar/utf8_to_32_test.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "hdr/errno_macros.h"
 #include "src/__support/error_or.h"
 #include "src/__support/wchar/character_converter.h"
 #include "src/__support/wchar/mbstate.h"
@@ -87,7 +88,7 @@ TEST(LlvmLibcCharacterConverterUTF8To32Test, InvalidByte) {
   LIBC_NAMESPACE::internal::CharacterConverter char_conv(&state);
   int err = char_conv.push(static_cast<char8_t>(ch));
 
-  ASSERT_EQ(err, -1);
+  ASSERT_EQ(err, EILSEQ);
 }
 
 TEST(LlvmLibcCharacterConverterUTF8To32Test, InvalidMultiByte) {
@@ -100,12 +101,12 @@ TEST(LlvmLibcCharacterConverterUTF8To32Test, InvalidMultiByte) {
 
   LIBC_NAMESPACE::internal::CharacterConverter char_conv(&state);
   int err = char_conv.push(static_cast<char8_t>(ch[0]));
-  ASSERT_EQ(err, -1);
+  ASSERT_EQ(err, EILSEQ);
   err = char_conv.push(static_cast<char8_t>(ch[1]));
   ASSERT_EQ(err, 0);
   // Prev byte was single byte so trying to push another should error.
   err = char_conv.push(static_cast<char8_t>(ch[2]));
-  ASSERT_EQ(err, -1);
+  ASSERT_EQ(err, EILSEQ);
   err = char_conv.push(static_cast<char8_t>(ch[3]));
   ASSERT_EQ(err, 0);
 }
@@ -127,7 +128,7 @@ TEST(LlvmLibcCharacterConverterUTF8To32Test, InvalidLastByte) {
   err = char_conv.push(static_cast<char8_t>(ch[2]));
   ASSERT_EQ(err, 0);
   err = char_conv.push(static_cast<char8_t>(ch[3]));
-  ASSERT_EQ(err, -1);
+  ASSERT_EQ(err, EILSEQ);
 }
 
 TEST(LlvmLibcCharacterConverterUTF8To32Test, ValidTwoByteWithExtraRead) {
@@ -144,7 +145,7 @@ TEST(LlvmLibcCharacterConverterUTF8To32Test, ValidTwoByteWithExtraRead) {
   ASSERT_EQ(err, 0);
   // Should produce an error on 3rd byte
   err = char_conv.push(static_cast<char8_t>(ch[2]));
-  ASSERT_EQ(err, -1);
+  ASSERT_EQ(err, EILSEQ);
 
   // Should produce an error since mbstate was reset
   auto wch = char_conv.pop_utf32();