Add compiler deprecation warnings for absl::ConvertDateTime() and absl::FromDateTime().

These have been marked deprecated in the comments for some time,
(since f340f773edab951656b19b6f1a77c964a78ec4c2) but the warnings
were never enabled.

A warning suppression is enabled for Abseil code so that when we
declare types in our code, we don't get a warning.

PiperOrigin-RevId: 532891102
Change-Id: Ife0c5696a061ea44769e02869e4e3d1196e86f9d

3 files changed, 43 insertions, 7 deletions

diff --git a/absl/base/attributes.h b/absl/base/attributes.h
index 3e5aafba..34a35538 100644
--- a/absl/base/attributes.h
+++ b/absl/base/attributes.h
@@ -685,6 +685,28 @@
 #define ABSL_DEPRECATED(message)
 #endif
 
+// When deprecating Abseil code, it is sometimes necessary to turn off the
+// warning within Abseil, until the deprecated code is actually removed. The
+// deprecated code can be surrounded with these directives to acheive that
+// result.
+//
+// class ABSL_DEPRECATED("Use Bar instead") Foo;
+//
+// ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
+// Baz ComputeBazFromFoo(Foo f);
+// ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
+#ifdef __GNUC__
+// Clang also supports these GCC pragmas.
+#define ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING \
+  _Pragma("GCC diagnostic push")             \
+  _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"")
+#define ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING \
+  _Pragma("GCC diagnostic pop")
+#else
+#define ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
+#define ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
+#endif  // __GNUC__
+
 // ABSL_CONST_INIT
 //
 // A variable declaration annotated with the `ABSL_CONST_INIT` attribute will
diff --git a/absl/time/time.cc b/absl/time/time.cc
index a11e8e9b..d983c12b 100644
--- a/absl/time/time.cc
+++ b/absl/time/time.cc
@@ -66,6 +66,7 @@ inline int64_t FloorToUnit(absl::Duration d, absl::Duration unit) {
              : q - 1;
 }
 
+ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
 inline absl::Time::Breakdown InfiniteFutureBreakdown() {
   absl::Time::Breakdown bd;
   bd.year = std::numeric_limits<int64_t>::max();
@@ -99,6 +100,7 @@ inline absl::Time::Breakdown InfinitePastBreakdown() {
   bd.zone_abbr = "-00";
   return bd;
 }
+ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 
 inline absl::TimeZone::CivilInfo InfiniteFutureCivilInfo() {
   TimeZone::CivilInfo ci;
@@ -120,6 +122,7 @@ inline absl::TimeZone::CivilInfo InfinitePastCivilInfo() {
   return ci;
 }
 
+ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
 inline absl::TimeConversion InfiniteFutureTimeConversion() {
   absl::TimeConversion tc;
   tc.pre = tc.trans = tc.post = absl::InfiniteFuture();
@@ -135,6 +138,7 @@ inline TimeConversion InfinitePastTimeConversion() {
   tc.normalized = true;
   return tc;
 }
+ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 
 // Makes a Time from sec, overflowing to InfiniteFuture/InfinitePast as
 // necessary. If sec is min/max, then consult cs+tz to check for overflow.
@@ -203,6 +207,7 @@ bool FindTransition(const cctz::time_zone& tz,
 // Time
 //
 
+ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
 absl::Time::Breakdown Time::In(absl::TimeZone tz) const {
   if (*this == absl::InfiniteFuture()) return InfiniteFutureBreakdown();
   if (*this == absl::InfinitePast()) return InfinitePastBreakdown();
@@ -227,6 +232,7 @@ absl::Time::Breakdown Time::In(absl::TimeZone tz) const {
   bd.zone_abbr = al.abbr;
   return bd;
 }
+ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 
 //
 // Conversions from/to other time types.
@@ -398,7 +404,7 @@ bool TimeZone::PrevTransition(Time t, CivilTransition* trans) const {
 //
 // Conversions involving time zones.
 //
-
+ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
 absl::TimeConversion ConvertDateTime(int64_t year, int mon, int day, int hour,
                                      int min, int sec, TimeZone tz) {
   // Avoids years that are too extreme for CivilSecond to normalize.
@@ -430,6 +436,7 @@ absl::TimeConversion ConvertDateTime(int64_t year, int mon, int day, int hour,
   }
   return tc;
 }
+ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 
 absl::Time FromTM(const struct tm& tm, absl::TimeZone tz) {
   civil_year_t tm_year = tm.tm_year;
diff --git a/absl/time/time.h b/absl/time/time.h
index 29178c77..37580805 100644
--- a/absl/time/time.h
+++ b/absl/time/time.h
@@ -802,8 +802,7 @@ class Time {
   // `absl::TimeZone`.
   //
   // Deprecated. Use `absl::TimeZone::CivilInfo`.
-  struct
-      Breakdown {
+  struct ABSL_DEPRECATED("Use `absl::TimeZone::CivilInfo`.") Breakdown {
     int64_t year;        // year (e.g., 2013)
     int month;           // month of year [1:12]
     int day;             // day of month [1:31]
@@ -829,7 +828,10 @@ class Time {
   // Returns the breakdown of this instant in the given TimeZone.
   //
   // Deprecated. Use `absl::TimeZone::At(Time)`.
+  ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
+  ABSL_DEPRECATED("Use `absl::TimeZone::At(Time)`.")
   Breakdown In(TimeZone tz) const;
+  ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 
   template <typename H>
   friend H AbslHashValue(H h, Time t) {
@@ -1323,8 +1325,7 @@ ABSL_ATTRIBUTE_PURE_FUNCTION inline Time FromCivil(CivilSecond ct,
 // `absl::ConvertDateTime()`. Legacy version of `absl::TimeZone::TimeInfo`.
 //
 // Deprecated. Use `absl::TimeZone::TimeInfo`.
-struct
-    TimeConversion {
+struct ABSL_DEPRECATED("Use `absl::TimeZone::TimeInfo`.") TimeConversion {
   Time pre;    // time calculated using the pre-transition offset
   Time trans;  // when the civil-time discontinuity occurred
   Time post;   // time calculated using the post-transition offset
@@ -1358,8 +1359,11 @@ struct
 //   // absl::ToCivilDay(tc.pre, tz).day() == 1
 //
 // Deprecated. Use `absl::TimeZone::At(CivilSecond)`.
+ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
+ABSL_DEPRECATED("Use `absl::TimeZone::At(CivilSecond)`.")
 TimeConversion ConvertDateTime(int64_t year, int mon, int day, int hour,
                                int min, int sec, TimeZone tz);
+ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 
 // FromDateTime()
 //
@@ -1376,9 +1380,12 @@ TimeConversion ConvertDateTime(int64_t year, int mon, int day, int hour,
 // Deprecated. Use `absl::FromCivil(CivilSecond, TimeZone)`. Note that the
 // behavior of `FromCivil()` differs from `FromDateTime()` for skipped civil
 // times. If you care about that see `absl::TimeZone::At(absl::CivilSecond)`.
-inline Time FromDateTime(int64_t year, int mon, int day, int hour,
-                         int min, int sec, TimeZone tz) {
+ABSL_DEPRECATED("Use `absl::FromCivil(CivilSecond, TimeZone)`.")
+inline Time FromDateTime(int64_t year, int mon, int day, int hour, int min,
+                         int sec, TimeZone tz) {
+  ABSL_INTERNAL_DISABLE_DEPRECATED_DECLARATION_WARNING
   return ConvertDateTime(year, mon, day, hour, min, sec, tz).pre;
+  ABSL_INTERNAL_RESTORE_DEPRECATED_DECLARATION_WARNING
 }
 
 // FromTM()