gnu: Add date.

* gnu/packages/wm.scm (date): New variable.
* gnu/packages/patches/date-output-pkg-config-files.patch: New file.
* gnu/local.mk: Add patch.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/local.mk

@@ -26,6 +26,7 @@
 # Copyright © 2019 Evan Straw <evan.straw99@gmail.com>
 # Copyright © 2019 Brett Gilio <brettg@gnu.org>
 # Copyright © 2019 Amin Bandali <mab@gnu.org>
+# Copyright © 2020 Brendan Tildesley <mail@brendan.scot>
 #
 # This file is part of GNU Guix.
 #
@@ -805,6 +806,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/cube-nocheck.patch			\
   %D%/packages/patches/cursynth-wave-rand.patch			\
   %D%/packages/patches/cvs-CVE-2017-12836.patch		\
+  %D%/packages/patches/date-output-pkg-config-files.patch	\
   %D%/packages/patches/darkice-workaround-fpermissive-error.patch	\
   %D%/packages/patches/dbus-helper-search-path.patch		\
   %D%/packages/patches/dbus-c++-gcc-compat.patch		\

gnu/packages/calendar.scm

@@ -7,6 +7,7 @@
 ;;; Copyright © 2016 Stefan Reichoer <stefan@xsteve.at>
 ;;; Copyright © 2018, 2019 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2020 Marius Bakke <mbakke@fastmail.com
+;;; Copyright © 2020 Brendan Tildesley <mail@brendan.scot>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -26,6 +27,7 @@
 (define-module (gnu packages calendar)
   #:use-module (gnu packages)
   #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix git-download)
   #:use-module (guix packages)
   #:use-module (guix download)
   #:use-module (guix build-system gnu)
@@ -48,6 +50,62 @@
   #:use-module (gnu packages xml)
   #:use-module (srfi srfi-26))
 
+(define-public date
+  ;; We make the same choice as the Arch package maintainer by choosing a
+  ;; recent commit to fix some bugs.
+  ;; https://github.com/Alexays/Waybar/issues/565
+  (let ((commit "9a0ee2542848ab8625984fc8cdbfb9b5414c0082"))
+    (package
+      (name "date")
+      (version (string-append "2.4.1-" (string-take commit 8)))
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/HowardHinnant/date.git")
+               (commit "9a0ee2542848ab8625984fc8cdbfb9b5414c0082")))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32 "0yxsn0hj22n61bjywysxqgfv7hj5xvsl6isma95fl8xrimpny083"))
+         (patches
+          ;; Install pkg-config files
+          ;; https://github.com/HowardHinnant/date/pull/538
+          (search-patches "date-output-pkg-config-files.patch"))))
+      (inputs `(("tzdata" ,tzdata)))
+      (build-system cmake-build-system)
+      (arguments
+       '(#:configure-flags (list "-DUSE_SYSTEM_TZ_DB=ON"
+                                 "-DBUILD_SHARED_LIBS=ON"
+                                 "-DBUILD_TZ_LIB=ON"
+                                 "-DENABLE_DATE_TESTING=ON")
+         #:phases
+         (modify-phases %standard-phases
+           (add-after 'unpack 'patch-bin-bash
+             (lambda* (#:key inputs #:allow-other-keys)
+               (substitute* "compile_fail.sh"
+                 (("/bin/bash") (which "bash")))
+               #t))
+           (add-after 'unpack 'patch-zoneinfo-path
+             (lambda* (#:key inputs #:allow-other-keys)
+               (substitute* "src/tz.cpp"
+                 (("/usr/share/zoneinfo")
+                  (string-append (assoc-ref inputs "tzdata") "/share/zoneinfo")))
+               #t))
+           (replace 'check
+             (lambda _
+               ;; Disable test that requires checking timezone that
+               ;; isn't set in the build environment.
+               (substitute* "CTestTestfile.cmake"
+                 (("add_test.tz_test_pass_zoned_time_deduction_test.*") "")
+                 (("set_tests_properties.tz_test_pass_zoned_time_deduction_test.*") ""))
+               (invoke "make" "testit"))))))
+      (synopsis "Date and time library for C++11 and C++14")
+      (description "Date is a header only C++ library that extends the chrono
+date algorithms library for calendar dates and durations.  It also provides
+the <tz.h> library for handling time zones and leap seconds.")
+      (home-page "https://howardhinnant.github.io/date/date.html")
+      (license license:expat))))
+
 (define-public libical
   (package
     (name "libical")

gnu/packages/patches/date-output-pkg-config-files.patch

@@ -0,0 +1,60 @@
+From e56b2dce7e89a92e1b9b35caa13b3e938c4cedea Mon Sep 17 00:00:00 2001
+From: Cole Mickens <cole.mickens@gmail.com>
+Date: Sun, 26 Jan 2020 01:27:08 -0800
+Subject: [PATCH] CMakeLists.txt: output date.pc for pkg-config
+
+---
+ CMakeLists.txt | 15 +++++++++++++++
+ date.pc.in     | 10 ++++++++++
+ 2 files changed, 25 insertions(+)
+ create mode 100644 date.pc.in
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index f30c473..fe778e8 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -128,6 +128,15 @@ if( BUILD_TZ_LIB )
+     endif( )
+ endif( )
+ 
++if ( BUILD_TZ_LIB )
++  # Cflags: -I${includedir} @TZ_COMPILE_DEFINITIONS@
++  set( TZ_COMPILE_DEFINITIONS "$<IF:$<TARGET_EXISTS:tz>,-D$<JOIN:$<TARGET_PROPERTY:tz,INTERFACE_COMPILE_DEFINITIONS>, -D>,>" )
++  configure_file(date.pc.in date.pc.cf @ONLY)
++  file( GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/date.pc"
++    INPUT "${CMAKE_CURRENT_BINARY_DIR}/date.pc.cf" )
++
++endif( )
++
+ #[===================================================================[
+    installation
+ #]===================================================================]
+@@ -171,6 +180,12 @@ install (
+   FILES cmake/dateConfig.cmake "${version_config}"
+   DESTINATION ${CONFIG_LOC})
+ 
++if ( BUILD_TZ_LIB )
++  install(
++    FILES ${CMAKE_BINARY_DIR}/date.pc
++    DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
++endif( )
++
+ #[===================================================================[
+    testing
+ #]===================================================================]
+diff --git a/date.pc.in b/date.pc.in
+new file mode 100644
+index 0000000..b9c4623
+--- /dev/null
++++ b/date.pc.in
+@@ -0,0 +1,10 @@
++prefix=@CMAKE_INSTALL_PREFIX@
++exec_prefix=@CMAKE_INSTALL_BINDIR@
++libdir=@CMAKE_INSTALL_LIB@
++includedir=@CMAKE_INSTALL_INCLUDE@
++
++Name: date
++Description: A date and time library based on the C++11/14/17 <chrono> header
++Version: @PACKAGE_VERSION@
++Libs: -L${libdir} -ltz
++Cflags: -I${includedir} @TZ_COMPILE_DEFINITIONS@