[Bug]: Build fails: error: use of undeclared identifier 'FP_NAN'

[yurivict]

Describe the issue

In file included from /usr/ports/devel/abseil/work/abseil-cpp-20230802.1/absl/time/internal/cctz/src/time_zone_format.cc:28:
In file included from /usr/ports/devel/abseil/work/abseil-cpp-20230802.1/absl/time/internal/cctz/include/cctz/time_zone.h:23:
In file included from /usr/include/c++/v1/chrono:746:
In file included from /usr/include/c++/v1/__chrono/convert_to_tm.h:13:
In file included from /usr/include/c++/v1/__chrono/day.h:15:
In file included from /usr/include/c++/v1/compare:145:
In file included from /usr/include/c++/v1/__compare/compare_partial_order_fallback.h:13:
In file included from /usr/include/c++/v1/__compare/partial_order.h:14:
In file included from /usr/include/c++/v1/__compare/weak_order.h:14:
In file included from /usr/include/c++/v1/__compare/strong_order.h:20:
In file included from /usr/include/c++/v1/cmath:317:
/usr/include/c++/v1/math.h:388:31: error: use of undeclared identifier 'FP_NAN'
  return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, __x);
                              ^
/usr/include/c++/v1/math.h:388:39: error: use of undeclared identifier 'FP_INFINITE'
  return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, __x);
                                      ^
/usr/include/c++/v1/math.h:388:52: error: use of undeclared identifier 'FP_NORMAL'
  return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, __x);
                                                   ^
/usr/include/c++/v1/math.h:388:63: error: use of undeclared identifier 'FP_SUBNORMAL'
  return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, __x);
                                                              ^
/usr/include/c++/v1/math.h:388:77: error: use of undeclared identifier 'FP_ZERO'
  return __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, __x);
                                                                            ^
/usr/include/c++/v1/math.h:393:21: error: use of undeclared identifier 'FP_ZERO'
  return __x == 0 ? FP_ZERO : FP_NORMAL;
                    ^
/usr/include/c++/v1/math.h:393:31: error: use of undeclared identifier 'FP_NORMAL'
  return __x == 0 ? FP_ZERO : FP_NORMAL;
                              ^

Version: 20230802.1
clang-16
FreeBSD 13.2

Steps to reproduce the problem

regular build

What version of Abseil are you using?

regular build

What operating system and version are you using?

FreeBSD 13.2

What compiler and version are you using?

clang-16

What build system are you using?

cmake

Additional context

Build in the FreeBSD ports' framework.

[yurivict]

This patch fixes the build:

--- absl/time/internal/cctz/src/time_zone_format.cc.orig        2023-09-18 14:40:01 UTC
+++ absl/time/internal/cctz/src/time_zone_format.cc
@@ -12,7 +12,7 @@
 //   See the License for the specific language governing permissions and
 //   limitations under the License.

-#if !defined(HAS_STRPTIME)
+#if 0 && !defined(HAS_STRPTIME)
 #if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__VXWORKS__)
 #define HAS_STRPTIME 1  // Assume everyone else has strptime().
 #endif
@@ -648,7 +648,7 @@ const char* ParseSubSeconds(const char* dp, detail::fe
 // Parses a string into a std::tm using strptime(3).
 const char* ParseTM(const char* dp, const char* fmt, std::tm* tm) {
   if (dp != nullptr) {
-    dp = strptime(dp, fmt, tm);
+    dp = ::strptime(dp, fmt, tm);
   }
   return dp;
 }

It's unclear why HAS_STRPTIME needs to be defined, and why is strptime ambiguous.

[danfe]

Duh, this was fixed in commit ded2ec0 but it happened after 20230802.1 release, I believe this issue can be closed now.