[libc-commits] [libc] [libc] Support %lc in printf (PR #169983)

[Shubh Pachchigar via libc-commits]

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@@ -3487,3 +3493,36 @@ TEST(LlvmLibcSPrintfTest, IndexModeParsing) {
                    "why would u do this, this is such   a pain. %");
 }
 #endif // LIBC_COPT_PRINTF_DISABLE_INDEX_MODE
+
+#ifndef LIBC_COPT_PRINTF_DISABLE_WIDE
+TEST(LlvmLibcSprintfTest, WideCharConversion) {
+  char buff[16];
+  int written;
+
+  // Euro sign is a 3-byte UTF-8 character.
+  written = LIBC_NAMESPACE::sprintf(buff, "%lc", static_cast<wchar_t>(L'€'));
+  EXPECT_EQ(written, 3);
+  ASSERT_STREQ(buff, "€");
+
+  // Euro sign left justified.
+  written = LIBC_NAMESPACE::sprintf(buff, "%-4lc", static_cast<wchar_t>(L'€'));
+  EXPECT_EQ(written, 6);
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shubhe25p wrote:

No, my wchar implementation was wrong as you pointed out, we should only print 4 character with one padding space and three byte for euro sign.

https://github.com/llvm/llvm-project/pull/169983