libstdc++: Fix __cpp_lib_chrono for old std::string ABI

The <chrono> header is incomplete for the old std::string ABI, because std::chrono::tzdb is only defined for the new ABI. The feature test macro advertising full C++20 support should not be defined for the old ABI. libstdc++-v3/ChangeLog: * include/bits/version.def (chrono): Add cxx11abi = yes. * include/bits/version.h: Regenerate. * testsuite/std/time/syn_c++20.cc: Adjust expected value for the feature test macro.
gcc-mirror · Jun 21, 2024 · f906b10 · f906b10
1 parent 510ce5e
commit f906b10
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Showing 3 changed files with 11 additions and 3 deletions.
diff --git a/libstdc++-v3/include/bits/version.def b/libstdc++-v3/include/bits/version.def
@@ -574,6 +574,7 @@ ftms = {
     v = 201907;
     cxxmin = 20;
     hosted = yes;
+    cxx11abi = yes; // std::chrono::tzdb requires cxx11 std::string
   };
   values = {
     v = 201611;

diff --git a/libstdc++-v3/include/bits/version.h b/libstdc++-v3/include/bits/version.h
@@ -639,7 +639,7 @@
 #undef __glibcxx_want_boyer_moore_searcher
 
 #if !defined(__cpp_lib_chrono)
-# if (__cplusplus >= 202002L) && _GLIBCXX_HOSTED
+# if (__cplusplus >= 202002L) && _GLIBCXX_USE_CXX11_ABI && _GLIBCXX_HOSTED
 #  define __glibcxx_chrono 201907L
 #  if defined(__glibcxx_want_all) || defined(__glibcxx_want_chrono)
 #   define __cpp_lib_chrono 201907L

diff --git a/libstdc++-v3/testsuite/std/time/syn_c++20.cc b/libstdc++-v3/testsuite/std/time/syn_c++20.cc
@@ -20,9 +20,16 @@
 
 #include <chrono>
 
+// std::chrono::tzdb is not defined for the old std::string ABI.
+#if _GLIBCXX_USE_CXX_ABI
+# define EXPECTED_VALUE 201907L
+#else
+# define EXPECTED_VALUE 201611L
+#endif
+
 #ifndef __cpp_lib_chrono
 # error "Feature test macro for chrono is missing in <chrono>"
-#elif __cpp_lib_chrono < 201907L
+#elif __cpp_lib_chrono < EXPECTED_VALUE
 # error "Feature test macro for chrono has wrong value in <chrono>"
 #endif
 
@@ -94,7 +101,7 @@ namespace __gnu_test
   using std::chrono::make12;
   using std::chrono::make24;
 
-#if _GLIBCXX_USE_CXX11_ABI
+#if __cpp_lib_chrono >= 201803L
   using std::chrono::tzdb;
   using std::chrono::tzdb_list;
   using std::chrono::get_tzdb;