[libcxx-commits] [libcxx] [libc++] Strengthen formatter test (PR #216475)

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llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Yihan Wang (yronglin)

<details>
<summary>Changes</summary>

```
#elif defined(__GLIBC__) && __GLIBC__ <= 2 && __GLIBC_MINOR__ < 29
      SV("%c='jeu. 01 janv. 1970 00:00:00 GMT'\t%Ec='jeu. 01 janv. 1970 00:00:00 GMT'\n"),
```

Some vendors(Rocky 8) backport https://sourceware.org/bugzilla/show_bug.cgi?id=24054 without changing the glibc version number, this PR probe the behavior directly to avoid the test failures on these platforms.




---
Full diff: https://github.com/llvm/llvm-project/pull/216475.diff


1 Files Affected:

- (modified) libcxx/test/std/time/time.syn/formatter_tests.h (+21-2) 


``````````diff
diff --git a/libcxx/test/std/time/time.syn/formatter_tests.h b/libcxx/test/std/time/time.syn/formatter_tests.h
index 798b953a377bd..7fce62aaf61ab 100644
--- a/libcxx/test/std/time/time.syn/formatter_tests.h
+++ b/libcxx/test/std/time/time.syn/formatter_tests.h
@@ -18,6 +18,7 @@
 
 #include <algorithm>
 #include <cassert>
+#include <ctime>
 #include <iostream>
 #include <set>
 #include <string>
@@ -26,6 +27,19 @@
 #define STR(S) MAKE_STRING(CharT, S)
 #define SV(S) MAKE_STRING_VIEW(CharT, S)
 
+inline bool glibc_strftime_uses_tm_zone() {
+#if defined(__GLIBC__)
+  // Some vendors backport https://sourceware.org/bugzilla/show_bug.cgi?id=24054
+  // without changing the glibc version number, so probe the behavior directly.
+  std::tm time{};
+  time.tm_zone = "UTC";
+  char buffer[4]{};
+  return std::strftime(buffer, sizeof(buffer), "%Z", &time) == 3 && std::string_view(buffer) == "UTC";
+#else
+  return false;
+#endif
+}
+
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 template <class CharT>
 using format_context = std::conditional_t<std::same_as<CharT, char>, std::format_context, std::wformat_context>;
@@ -36,10 +50,15 @@ using format_context = std::format_context;
 
 template <class CharT, class... Args>
 void check(std::basic_string_view<CharT> expected, test_format_string<CharT, Args...> fmt, Args&&... args) {
+  std::basic_string<CharT> adjusted{expected};
+  if (glibc_strftime_uses_tm_zone()) {
+    for (std::size_t pos = 0; (pos = adjusted.find(SV("GMT"), pos)) != std::basic_string<CharT>::npos; pos += 3)
+      adjusted.replace(pos, 3, SV("UTC"));
+  }
   std::basic_string<CharT> out = std::format(fmt, std::forward<Args>(args)...);
-  TEST_REQUIRE(out == expected,
+  TEST_REQUIRE(out == adjusted,
                TEST_WRITE_CONCATENATED(
-                   "\nFormat string   ", fmt.get(), "\nExpected output ", expected, "\nActual output   ", out, '\n'));
+                   "\nFormat string   ", fmt.get(), "\nExpected output ", adjusted, "\nActual output   ", out, '\n'));
 }
 
 template <class CharT, class... Args>

``````````

</details>


https://github.com/llvm/llvm-project/pull/216475