[date] Add tz recipe as a dependency

recipes/date/all/conandata.yml

@@ -13,10 +13,18 @@ patches:
     - patch_file: "patches/cmake-3.0.1.patch"
       patch_description: "Disable string view to workaround clang 5 not having it"
       patch_type: "portability"
+    - patch_file: "patches/load-tzdb-from-envvar-3.0.x.patch"
+      patch_description: "Allow TZDB to be loaded from the TZDATA environment variable"
+      patch_type: "portability"
+      patch_source: "https://github.com/HowardHinnant/date/pull/807"
   "3.0.0":
     - patch_file: "patches/cmake-3.0.0.patch"
       patch_description: "Disable string view to workaround clang 5 not having it"
       patch_type: "portability"
+    - patch_file: "patches/load-tzdb-from-envvar-3.0.x.patch"
+      patch_description: "Allow TZDB to be loaded from the TZDATA environment variable"
+      patch_type: "portability"
+      patch_source: "https://github.com/HowardHinnant/date/pull/807"
   "2.4.1":
     - patch_file: "patches/0001-fix-uwp.patch"
       patch_description: "Fix Universal Windows Platform (UWP) unhandled exception support. See https://github.com/microsoft/vcpkg/pull/8151#issuecomment-531175393."
@@ -27,3 +35,7 @@ patches:
     - patch_file: "patches/string_view.patch"
       patch_description: "Disable string view to workaround clang 5 not having it"
       patch_type: "portability"
+    - patch_file: "patches/load-tzdb-from-envvar-2.4.1.patch"
+      patch_description: "Allow TZDB to be loaded from the TZDATA environment variable"
+      patch_type: "portability"
+      patch_source: "https://github.com/HowardHinnant/date/pull/807"

recipes/date/all/conanfile.py

@@ -3,6 +3,7 @@
 from conan.tools.cmake import CMake, CMakeToolchain, CMakeDeps, cmake_layout
 from conan.tools.files import get, rmdir, apply_conandata_patches, export_conandata_patches, copy
 from conan.tools.scm import Version
+from conan.errors import ConanInvalidConfiguration
 
 import os
 
@@ -22,14 +23,18 @@ class DateConan(ConanFile):
         "shared": [True, False],
         "fPIC": [True, False],
         "header_only": [True, False],
-        "use_system_tz_db": [True, False],
+        "use_system_tz_db": [True, False, "deprecated"],
+        "with_tzdb": [False, "system", "download", "manual", "tz"],
+        "with_db_format": ["source", "binary"],
         "use_tz_db_in_dot": [True, False],
     }
     default_options = {
         "shared": False,
         "fPIC": True,
         "header_only": False,
         "use_system_tz_db": False,
+        "with_tzdb": "tz",
+        "with_db_format": "source",
         "use_tz_db_in_dot": False,
     }
 
@@ -53,8 +58,10 @@ def layout(self):
         cmake_layout(self, src_folder="src")
 
     def requirements(self):
-        if not self.options.header_only and not self.options.use_system_tz_db:
+        if not self.options.header_only and not self.options.use_system_tz_db and self.options.with_tzdb == "download":
             self.requires("libcurl/[>=7.78 <9]")
+        if self.options.with_tzdb == "tz":
+            self.requires("tz/2023c", options={"with_binary_db": self.options.with_db_format == "binary"})
 
     def package_id(self):
         if self.info.options.header_only:
@@ -63,16 +70,25 @@ def package_id(self):
     def validate(self):
         if self.settings.compiler.get_safe("cppstd"):
             check_min_cppstd(self, 11)
+        if self.options.with_tzdb != "download" and self.options.use_tz_db_in_dot:
+            raise ConanInvalidConfiguration("'use_tz_db_in_dot=True' is only valid when 'with_tzdb=\"download\"'")
+        if self.options.use_system_tz_db and (self.options.with_tzdb not in [False, "system"]):
+            raise ConanInvalidConfiguration("'use_system_tz_db' is deprecated. You must set 'with_tzdb=system'")
+        if (self.options.use_system_tz_db or self.options.with_tzdb == "system") and not self.options.with_db_format == "binary":
+            raise ConanInvalidConfiguration("date only supports using the operating system database in a binary format. You must set 'with_db_format=binary'")
+        if self.settings.os == "Windows" and self.options.with_db_format == "binary":
+            raise ConanInvalidConfiguration("date does not currently support parsing the binary tzdb on Windows. An attempt has been made to introduce this in https://github.com/HowardHinnant/date/pull/611, so if this is functionality you would like please feel free to adapt this to a conan patch.")
 
     def source(self):
         get(self, **self.conan_data["sources"][self.version], strip_root=True)
 
     def generate(self):
         tc = CMakeToolchain(self)
         tc.variables["ENABLE_DATE_TESTING"] = False
-        tc.variables["USE_SYSTEM_TZ_DB"] = self.options.use_system_tz_db
+        tc.variables["USE_SYSTEM_TZ_DB"] = (self.options.use_system_tz_db or self.options.with_tzdb in ["system", "tz"]) and self.options.with_db_format == "binary"
         tc.variables["USE_TZ_DB_IN_DOT"] = self.options.use_tz_db_in_dot
         tc.variables["BUILD_TZ_LIB"] = not self.options.header_only
+        tc.variables["MANUAL_TZ_DB"] = self.options.with_tzdb in ["manual", "tz"] and not self.options.with_db_format == "binary"
         # workaround for clang 5 not having string_view
         if Version(self.version) >= "3.0.0" and self.settings.compiler == "clang" \
                 and Version(self.settings.compiler.version) <= "5.0":
@@ -123,10 +139,10 @@ def package_info(self):
                 self.cpp_info.components["date-tz"].system_libs.append("pthread")
                 self.cpp_info.components["date-tz"].system_libs.append("m")
 
-            if not self.options.use_system_tz_db:
+            if self.options.with_tzdb == "download":
                 self.cpp_info.components["date-tz"].requires.append("libcurl::libcurl")
 
-            if self.options.use_system_tz_db and not self.settings.os == "Windows":
+            if (self.options.use_system_tz_db or self.options.with_tzdb in ["system", "tz"]) and self.options.with_db_format == "binary":
                 use_os_tzdb = 1
             else:
                 use_os_tzdb = 0

recipes/date/all/patches/load-tzdb-from-envvar-2.4.1.patch

@@ -0,0 +1,117 @@
+From 73ed8608827b3256e4f97415c9e2014fd31da2be Mon Sep 17 00:00:00 2001
+From: Samuel Dowling <samuel.dowling@protonmail.com>
+Date: Sat, 13 Jan 2024 19:57:49 +1030
+Subject: [PATCH] Add ability to specify timezone database location via
+ environment variable
+
+This adds the ability for a user to populate the TZDATA environment
+variable to specify the location in which to look for the timezone
+database, which allows for a runtime query of this location. Without
+this, date currently only supports compile time determination of the
+database location.
+
+This facilitates the ability to:
+* Use a timezone database provided by a package manager
+* Keep the timezone database up to date without re-compilation
+* Be flexible about where the timezone database is stored
+
+Closes #788
+---
+ CMakeLists.txt | 23 +++++++++++++++--------
+ src/tz.cpp     | 19 +++++++++++++++++++
+ 2 files changed, 34 insertions(+), 8 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 7bc93df..ac989c8 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -23,6 +23,7 @@ function( print_option OPT )
+ endfunction( )
+
+ print_option( USE_SYSTEM_TZ_DB )
++print_option( MANUAL_TZ_DB )
+ print_option( USE_TZ_DB_IN_DOT )
+ print_option( BUILD_SHARED_LIBS  )
+ print_option( ENABLE_DATE_TESTING )
+@@ -45,20 +46,26 @@ set( HEADER_FILES
+
+ add_library( tz ${HEADER_FILES} ${SOURCE_FOLDER}/tz.cpp )
+
+-if( USE_SYSTEM_TZ_DB )
++if( USE_SYSTEM_TZ_DB OR MANUAL_TZ_DB )
+ 	target_compile_definitions( tz PRIVATE -DUSE_AUTOLOAD=0 )
+ 	target_compile_definitions( tz PRIVATE -DHAS_REMOTE_API=0 )
+-	# cannot set USE_OS_TZDB to 1 on Windows
+-	if( NOT WIN32 )
+-		target_compile_definitions( tz PUBLIC -DUSE_OS_TZDB=1 )
+-	endif( )
+ else( )
+ 	target_compile_definitions( tz PRIVATE -DUSE_AUTOLOAD=1 )
+ 	target_compile_definitions( tz PRIVATE -DHAS_REMOTE_API=1 )
+-	target_compile_definitions( tz PUBLIC -DUSE_OS_TZDB=0 )
+-	find_package( CURL REQUIRED )
++endif( )
++
++if ( USE_SYSTEM_TZ_DB AND NOT MANUAL_TZ_DB )
++    target_compile_definitions( tz PRIVATE -DINSTALL=. )
++    target_compile_definitions( tz PUBLIC -DUSE_OS_TZDB=1 )
++else( )
++    target_compile_definitions( tz PUBLIC USE_OS_TZDB=0 )
++endif( )
++
++if( NOT USE_SYSTEM_TZ_DB AND NOT MANUAL_TZ_DB )
++    find_package( CURL REQUIRED )
++    include_directories( SYSTEM ${CURL_INCLUDE_DIRS} )
+     set( OPTIONAL_LIBRARIES CURL::libcurl )
+-endif()
++endif( )
+
+ if( BUILD_SHARED_LIBS )
+     target_compile_definitions( tz PRIVATE -DDATE_BUILD_DLL=1 )
+diff --git a/src/tz.cpp b/src/tz.cpp
+index f4a819b..fd7cd9f 100644
+--- a/src/tz.cpp
++++ b/src/tz.cpp
+@@ -81,6 +81,9 @@
+ #  endif  // __MINGW32__
+
+ #  include <windows.h>
++#  if !defined(S_ISDIR) && defined(S_IFMT) && defined(_S_IFDIR)
++#    define S_ISDIR(m) (((m) & S_IFMT) == _S_IFDIR)
++#  endif
+ #endif  // _WIN32
+
+ #include "date/tz_private.h"
+@@ -276,6 +279,14 @@ access_install()
+     #undef STRINGIZE
+ #endif  // !INSTALL
+
++    {
++        static char* tz_local_env = getenv("TZDATA");
++        if (tz_local_env != nullptr) {
++            static std::string tz_local_env_s = tz_local_env;
++            return tz_local_env_s;
++        }
++    }
++
+     return install;
+ }
+
+@@ -330,6 +341,14 @@ discover_tz_dir()
+     CONSTDATA auto tz_dir_default = "/usr/share/zoneinfo";
+     CONSTDATA auto tz_dir_buildroot = "/usr/share/zoneinfo/uclibc";
+
++    {
++        static char* tz_local_env = getenv("TZDATA");
++        if (tz_local_env != nullptr) {
++            static std::string tz_local_env_s = tz_local_env;
++            return tz_local_env_s;
++        }
++    }
++
+     // Check special path which is valid for buildroot with uclibc builds
+     if(stat(tz_dir_buildroot, &sb) == 0 && S_ISDIR(sb.st_mode))
+         return tz_dir_buildroot;
+-- 
+2.43.0.windows.1
+

recipes/date/all/patches/load-tzdb-from-envvar-3.0.x.patch

@@ -0,0 +1,69 @@
+From 8b2cceb71f65f6aa6bdb3ffa63a63400214d5f1b Mon Sep 17 00:00:00 2001
+From: Samuel Dowling <samuel.dowling@protonmail.com>
+Date: Sat, 13 Jan 2024 19:57:49 +1030
+Subject: [PATCH] Add ability to specify timezone database location via
+ environment variable
+
+This adds the ability for a user to populate the TZDATA environment
+variable to specify the location in which to look for the timezone
+database, which allows for a runtime query of this location. Without
+this, date currently only supports compile time determination of the
+database location.
+
+This facilitates the ability to:
+* Use a timezone database provided by a package manager
+* Keep the timezone database up to date without re-compilation
+* Be flexible about where the timezone database is stored
+
+Closes #788
+---
+ src/tz.cpp | 19 +++++++++++++++++++
+ 1 file changed, 19 insertions(+)
+
+diff --git a/src/tz.cpp b/src/tz.cpp
+index 26babbd..6d010b8 100644
+--- a/src/tz.cpp
++++ b/src/tz.cpp
+@@ -81,6 +81,9 @@
+ #  endif  // __MINGW32__
+
+ #  include <windows.h>
++#  if !defined(S_ISDIR) && defined(S_IFMT) && defined(_S_IFDIR)
++#    define S_ISDIR(m) (((m) & S_IFMT) == _S_IFDIR)
++#  endif
+ #endif  // _WIN32
+
+ #include "date/tz_private.h"
+@@ -299,6 +302,14 @@ access_install()
+     #undef STRINGIZE
+ #endif  // !INSTALL
+
++    {
++        static char* tz_local_env = getenv("TZDATA");
++        if (tz_local_env != nullptr) {
++            static std::string tz_local_env_s = tz_local_env;
++            return tz_local_env_s;
++        }
++    }
++
+     return install;
+ }
+
+@@ -353,6 +364,14 @@ discover_tz_dir()
+     CONSTDATA auto tz_dir_default = "/usr/share/zoneinfo";
+     CONSTDATA auto tz_dir_buildroot = "/usr/share/zoneinfo/uclibc";
+
++    {
++        static char* tz_local_env = getenv("TZDATA");
++        if (tz_local_env != nullptr) {
++            static std::string tz_local_env_s = tz_local_env;
++            return tz_local_env_s;
++        }
++    }
++
+     // Check special path which is valid for buildroot with uclibc builds
+     if(stat(tz_dir_buildroot, &sb) == 0 && S_ISDIR(sb.st_mode))
+         return tz_dir_buildroot;
+-- 
+2.43.0.windows.1
+

recipes/date/all/test_package/test_package.cpp

@@ -15,17 +15,15 @@ class ZoneOffset {
     auto to_local(date::sys_time<Duration> tp) const
         -> date::local_time<typename std::common_type<Duration, std::chrono::minutes>::type> {
         using namespace date;
-        using namespace std::chrono;
-        using LT = local_time<typename std::common_type<Duration, minutes>::type>;
+        using LT = local_time<typename std::common_type<Duration, std::chrono::minutes>::type>;
         return LT{(tp + _offset).time_since_epoch()};
     }
 
     template <class Duration>
     auto to_sys(date::local_time<Duration> tp) const
         -> date::sys_time<typename std::common_type<Duration, std::chrono::minutes>::type> {
         using namespace date;
-        using namespace std::chrono;
-        using ST = sys_time<typename std::common_type<Duration, minutes>::type>;
+        using ST = sys_time<typename std::common_type<Duration, std::chrono::minutes>::type>;
         return ST{(tp - _offset).time_since_epoch()};
     }
 
@@ -34,7 +32,6 @@ class ZoneOffset {
 };
 
 int main() {
-    using namespace std::chrono;
     using namespace date;
 
     auto date1 = 2015_y/March/22;
@@ -44,8 +41,8 @@ int main() {
     auto date3 = 22_d/March/2015;
     std::cout << date3 << '\n';
 
-    ZoneOffset p3_45{hours{3} + minutes{45}};
-    zoned_time<milliseconds, ZoneOffset*> zt{&p3_45, floor<milliseconds>(system_clock::now())};
+    ZoneOffset p3_45{std::chrono::hours{3} + std::chrono::minutes{45}};
+    zoned_time<std::chrono::milliseconds, ZoneOffset*> zt{&p3_45, floor<std::chrono::milliseconds>(std::chrono::system_clock::now())};
     std::cout << zt.get_sys_time() << " (sys time)\n";
     std::cout << zt.get_local_time() << " (local time)\n";