[libc-commits] [libc] [libc] Support ls in printf (PR #178841)

[Michael Jones via libc-commits]

================
@@ -3582,4 +3582,94 @@ TEST(LlvmLibcSprintfTest, WideCharConversion) {
             -1);
   ASSERT_ERRNO_EQ(EILSEQ);
 }
+
+TEST(LlvmLibcSprintfTest, WideCharStringConversion) {
+  char buff[64];
+  int written;
+
+  // Basic test.
+  written = LIBC_NAMESPACE::sprintf(buff, "%ls", L"Hello, World!");
+  EXPECT_EQ(written, 13);
+  ASSERT_STREQ_LEN(written, buff, "Hello, World!");
+
+  // Left justified.
+  written = LIBC_NAMESPACE::sprintf(buff, "%-10ls", L"Hello, World!");
+  EXPECT_EQ(written, 13);
+  ASSERT_STREQ_LEN(written, buff, "Hello, World!");
+
+  // Precision test.
+  written = LIBC_NAMESPACE::sprintf(buff, "%.5ls", L"Hello, World!");
+  EXPECT_EQ(written, 5);
+  ASSERT_STREQ_LEN(written, buff, "Hello");
+
+  // Test ¢ which is 2 bytes multibyte character.
+  written = LIBC_NAMESPACE::sprintf(buff, "%ls", L"¢");
+  EXPECT_EQ(written, 2);
+  ASSERT_STREQ_LEN(written, buff, "¢");
+
+  // Test € which is 3 bytes multibyte character.
+  written = LIBC_NAMESPACE::sprintf(buff, "%ls", L"€");
+  EXPECT_EQ(written, 3);
+  ASSERT_STREQ_LEN(written, buff, "€");
+
+  // Test 😀 which is 4 bytes multibyte character
+  written = LIBC_NAMESPACE::sprintf(buff, "%ls", L"😀");
+  EXPECT_EQ(written, 4);
+  ASSERT_STREQ_LEN(written, buff, "😀");
+
+  // Test string with multiple multibyte characters.
+  written = LIBC_NAMESPACE::sprintf(buff, "%ls", L"¢€😀");
+  EXPECT_EQ(written, 9);
+  ASSERT_STREQ_LEN(written, buff, "¢€😀");
+
+  // Width with multibyte characters.
+  written = LIBC_NAMESPACE::sprintf(buff, "%2ls", L"¢€😀");
+  EXPECT_EQ(written, 9);
+  ASSERT_STREQ_LEN(written, buff, "¢€😀");
+
+  // Width with multibyte characters and padding.
+  written = LIBC_NAMESPACE::sprintf(buff, "%12ls", L"¢€😀");
+  EXPECT_EQ(written, 12);
+  ASSERT_STREQ_LEN(written, buff, "   ¢€😀");
+
+  // Precision with multibyte characters.
+  written = LIBC_NAMESPACE::sprintf(buff, "%.4ls", L"¢€😀");
----------------
michaelrj-google wrote:

make sure you have precision tests with all four lengths of character. Ideally there would be one ensuring the smiley shows up as the leading character  when the precision is 4 or 5 but not when the precision is 3.

https://github.com/llvm/llvm-project/pull/178841