[libc] Implemented mblen functions

Implemented mblen and mbrlen as well as tests

Author: Sriya Pratipati

libc/test/src/wchar/CMakeLists.txt

@@ -77,16 +77,16 @@ add_libc_test(
 )
 
 add_libc_test(
-  mbrtowc_test
+  mbrlen_test
   SUITE
     libc_wchar_unittests
   SRCS
-    mbrtowc_test.cpp
+    mbrlen_test.cpp
   DEPENDS
     libc.src.__support.libc_errno
     libc.src.__support.wchar.mbstate
     libc.src.string.memset
-    libc.src.wchar.mbrtowc
+    libc.src.wchar.mbrlen
     libc.hdr.types.mbstate_t
     libc.test.UnitTest.ErrnoCheckingTest
 )

libc/test/src/wchar/mbrlen_test.cpp

@@ -1,4 +1,4 @@
-//===-- Unittests for mblen -----------------------------------------------===//
+//===-- Unittests for mbrlen ----------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -8,98 +8,132 @@
 
 #include "hdr/types/wchar_t.h"
 #include "src/__support/libc_errno.h"
-#include "src/wchar/mblen.h"
+#include "src/__support/wchar/mbstate.h"
+#include "src/string/memset.h"
+#include "src/wchar/mbrlen.h"
 #include "test/UnitTest/ErrnoCheckingTest.h"
 #include "test/UnitTest/Test.h"
 
-using LlvmLibcMBLenTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+using LlvmLibcMBRLenTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
 
-TEST_F(LlvmLibcMBLenTest, OneByte) {
+TEST_F(LlvmLibcMBRLenTest, OneByte) {
   const char *ch = "A";
-  int n = LIBC_NAMESPACE::mblen(ch, 1);
+  mbstate_t mb;
+  LIBC_NAMESPACE::memset(&mb, 0, sizeof(mbstate_t));
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 1, &mb);
   ASSERT_ERRNO_SUCCESS();
-  ASSERT_EQ(n, 1);
+  ASSERT_EQ(n, static_cast<size_t>(1));
 
   // Should fail since we have not read enough
-  n = LIBC_NAMESPACE::mblen(ch, 0);
+  n = LIBC_NAMESPACE::mbrlen(ch, 0, &mb);
   ASSERT_ERRNO_SUCCESS();
-  ASSERT_EQ(n, -1);
+  ASSERT_EQ(n, static_cast<size_t>(-2));
 }
 
-TEST_F(LlvmLibcMBLenTest, TwoByte) {
+TEST_F(LlvmLibcMBRLenTest, TwoByte) {
   const char ch[2] = {static_cast<char>(0xC2),
                       static_cast<char>(0x8E)}; // Ž car symbol
-  int n = LIBC_NAMESPACE::mblen(ch, 4);
+  mbstate_t mb;
+  LIBC_NAMESPACE::memset(&mb, 0, sizeof(mbstate_t));
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 4, nullptr);
   ASSERT_ERRNO_SUCCESS();
-  ASSERT_EQ(n, 2);
+  ASSERT_EQ(static_cast<int>(n), 2);
 
   // Should fail since we have not read enough
-  n = LIBC_NAMESPACE::mblen(ch, 1);
-  ASSERT_EQ(n, -1);
+  n = LIBC_NAMESPACE::mbrlen(ch, 1, &mb);
+  ASSERT_EQ(static_cast<int>(n), -2);
+  ASSERT_ERRNO_SUCCESS();
+  // Should pass after trying to read next byte
+  n = LIBC_NAMESPACE::mbrlen(ch + 1, 1, &mb);
+  ASSERT_EQ(static_cast<int>(n), 1);
   ASSERT_ERRNO_SUCCESS();
-  // Should fail after trying to read next byte too
-  n = LIBC_NAMESPACE::mblen(ch + 1, 1);
-  ASSERT_EQ(n, -1);
-  // This one should be an invalid starting byte so should set errno
-  ASSERT_ERRNO_EQ(EILSEQ);
 }
 
-TEST_F(LlvmLibcMBLenTest, ThreeByte) {
+TEST_F(LlvmLibcMBRLenTest, ThreeByte) {
   const char ch[3] = {static_cast<char>(0xE2), static_cast<char>(0x88),
                       static_cast<char>(0x91)}; // ∑ sigma symbol
-  int n = LIBC_NAMESPACE::mblen(ch, 3);
-  ASSERT_EQ(n, 3);
+  mbstate_t mb;
+  LIBC_NAMESPACE::memset(&mb, 0, sizeof(mbstate_t));
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 3, &mb);
+  ASSERT_EQ(static_cast<int>(n), 3);
   ASSERT_ERRNO_SUCCESS();
 
   // Should fail since we have not read enough
-  n = LIBC_NAMESPACE::mblen(ch, 2);
-  ASSERT_EQ(n, -1);
+  n = LIBC_NAMESPACE::mbrlen(ch, 2, &mb);
+  ASSERT_EQ(static_cast<int>(n), -2);
   ASSERT_ERRNO_SUCCESS();
 }
 
-TEST_F(LlvmLibcMBLenTest, FourByte) {
+TEST_F(LlvmLibcMBRLenTest, FourByte) {
   const char ch[4] = {static_cast<char>(0xF0), static_cast<char>(0x9F),
                       static_cast<char>(0xA4),
                       static_cast<char>(0xA1)}; // 🤡 clown emoji
-  int n = LIBC_NAMESPACE::mblen(ch, 4);
-  ASSERT_EQ(n, 4);
+  mbstate_t mb;
+  LIBC_NAMESPACE::memset(&mb, 0, sizeof(mbstate_t));
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 4, &mb);
+  ASSERT_EQ(static_cast<int>(n), 4);
+  ASSERT_ERRNO_SUCCESS();
+
+  // Should fail since we have not read enough
+  n = LIBC_NAMESPACE::mbrlen(ch, 2, &mb);
+  ASSERT_EQ(static_cast<int>(n), -2);
   ASSERT_ERRNO_SUCCESS();
 
   // Should fail since we have not read enough
-  n = LIBC_NAMESPACE::mblen(ch, 2);
-  ASSERT_EQ(n, -1);
+  n = LIBC_NAMESPACE::mbrlen(ch + 2, 1, &mb);
+  ASSERT_EQ(static_cast<int>(n), -2);
+  ASSERT_ERRNO_SUCCESS();
+
+  // Should pass after reading final byte
+  n = LIBC_NAMESPACE::mbrlen(ch + 3, 5, &mb);
+  ASSERT_EQ(static_cast<int>(n), 1);
   ASSERT_ERRNO_SUCCESS();
 }
 
-TEST_F(LlvmLibcMBLenTest, InvalidByte) {
+TEST_F(LlvmLibcMBRLenTest, InvalidByte) {
   const char ch[1] = {static_cast<char>(0x80)};
-  int n = LIBC_NAMESPACE::mblen(ch, 1);
-  ASSERT_EQ(n, -1);
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 1, nullptr);
+  ASSERT_EQ(static_cast<int>(n), -1);
   ASSERT_ERRNO_EQ(EILSEQ);
 }
 
-TEST_F(LlvmLibcMBLenTest, InvalidMultiByte) {
+TEST_F(LlvmLibcMBRLenTest, InvalidMultiByte) {
   const char ch[4] = {static_cast<char>(0x80), static_cast<char>(0x00),
                       static_cast<char>(0x80),
                       static_cast<char>(0x00)}; // invalid sequence of bytes
+  mbstate_t mb;
+  LIBC_NAMESPACE::memset(&mb, 0, sizeof(mbstate_t));
   // Trying to push all 4 should error
-  int n = LIBC_NAMESPACE::mblen(ch, 4);
-  ASSERT_EQ(n, -1);
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 4, &mb);
+  ASSERT_EQ(static_cast<int>(n), -1);
   ASSERT_ERRNO_EQ(EILSEQ);
 
   // Trying to push the second and third should correspond to null wc
-  n = LIBC_NAMESPACE::mblen(ch + 1, 2);
-  ASSERT_EQ(n, 0);
+  n = LIBC_NAMESPACE::mbrlen(ch + 1, 2, &mb);
+  ASSERT_EQ(static_cast<int>(n), 0);
   ASSERT_ERRNO_SUCCESS();
 }
 
-TEST_F(LlvmLibcMBLenTest, NullString) {
+TEST_F(LlvmLibcMBRLenTest, NullString) {
   // reading on nullptr should return 0
-  int n = LIBC_NAMESPACE::mblen(nullptr, 2);
-  ASSERT_EQ(n, 0);
+  size_t n = LIBC_NAMESPACE::mbrlen(nullptr, 2, nullptr);
+  ASSERT_EQ(static_cast<int>(n), 0);
   ASSERT_ERRNO_SUCCESS();
   // reading a null terminator should return 0
   const char *ch = "\0";
-  n = LIBC_NAMESPACE::mblen(ch, 1);
-  ASSERT_EQ(n, 0);
+  n = LIBC_NAMESPACE::mbrlen(ch, 1, nullptr);
+  ASSERT_EQ(static_cast<int>(n), 0);
+}
+
+TEST_F(LlvmLibcMBRLenTest, InvalidMBState) {
+  const char ch[4] = {static_cast<char>(0xC2), static_cast<char>(0x8E),
+                      static_cast<char>(0xC7), static_cast<char>(0x8C)};
+  mbstate_t *mb;
+  LIBC_NAMESPACE::internal::mbstate inv;
+  inv.total_bytes = 6;
+  mb = reinterpret_cast<mbstate_t *>(&inv);
+  // invalid mbstate should error
+  size_t n = LIBC_NAMESPACE::mbrlen(ch, 2, mb);
+  ASSERT_EQ(static_cast<int>(n), -1);
+  ASSERT_ERRNO_EQ(EINVAL);
 }