From 3606a42c525b7f04fec4f6d2b814ac6af30c49c0 Mon Sep 17 00:00:00 2001
From: "Bernhard M. Wiedemann" <githubbmw@lsmod.de>
Date: Sun, 22 Jan 2017 16:54:24 +0000
Subject: [PATCH 1/2] make build reproducible

by allowing build systems to use a constant date instead of the current one
see https://reproducible-builds.org/ for why this is good
and https://reproducible-builds.org/specs/source-date-epoch/
for the definition of this variable

This call is designed to work with GNU date. If BSD support is a concern, it can be added.
---
 cmake/today.cmake | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/cmake/today.cmake b/cmake/today.cmake
index 51d0031a8..8d008525c 100644
--- a/cmake/today.cmake
+++ b/cmake/today.cmake
@@ -7,7 +7,11 @@ MACRO (TODAY RESULT)
         EXECUTE_PROCESS(COMMAND "cmd" " /C date +%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
         string(REGEX REPLACE "(..)/(..)/..(..).*" "\\1/\\2/\\3" ${RESULT} ${${RESULT}})
     ELSEIF(UNIX)
-        EXECUTE_PROCESS(COMMAND "date" "+%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
+        if (DEFINED ENV{SOURCE_DATE_EPOCH})
+            EXECUTE_PROCESS(COMMAND "date" "-u" "-d" "@$ENV{SOURCE_DATE_EPOCH}" "+%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
+        else ()
+            EXECUTE_PROCESS(COMMAND "date" "+%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
+        endif ()
         string(REGEX REPLACE "(..)/(..)/..(..).*" "\\1/\\2/\\3" ${RESULT} ${${RESULT}})
     ELSE (WIN32)
         MESSAGE(SEND_ERROR "date not implemented")

From 00d71f62169b2739b43715670e3d83eb0205e4cc Mon Sep 17 00:00:00 2001
From: Armin Novak <armin.novak@thincast.com>
Date: Mon, 23 Jan 2017 11:25:29 +0100
Subject: [PATCH 2/2] Use CMake TIMESTAMP, remove newline from TODAY

---
 cmake/today.cmake | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/cmake/today.cmake b/cmake/today.cmake
index 8d008525c..d2f5eaa87 100644
--- a/cmake/today.cmake
+++ b/cmake/today.cmake
@@ -3,18 +3,10 @@
 # YYYY-MM-DD
 #
 MACRO (TODAY RESULT)
-    IF (WIN32)
-        EXECUTE_PROCESS(COMMAND "cmd" " /C date +%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
-        string(REGEX REPLACE "(..)/(..)/..(..).*" "\\1/\\2/\\3" ${RESULT} ${${RESULT}})
-    ELSEIF(UNIX)
-        if (DEFINED ENV{SOURCE_DATE_EPOCH})
-            EXECUTE_PROCESS(COMMAND "date" "-u" "-d" "@$ENV{SOURCE_DATE_EPOCH}" "+%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
-        else ()
-            EXECUTE_PROCESS(COMMAND "date" "+%Y-%m-%d" OUTPUT_VARIABLE ${RESULT})
-        endif ()
-        string(REGEX REPLACE "(..)/(..)/..(..).*" "\\1/\\2/\\3" ${RESULT} ${${RESULT}})
-    ELSE (WIN32)
-        MESSAGE(SEND_ERROR "date not implemented")
-        SET(${RESULT} 000000)
-    ENDIF (WIN32)
+    if (DEFINED ENV{SOURCE_DATE_EPOCH} AND NOT WIN32)
+        EXECUTE_PROCESS(COMMAND "date" "-u" "-d" "@$ENV{SOURCE_DATE_EPOCH}" "+%Y-%m-%d"
+                        OUTPUT_VARIABLE ${RESULT} OUTPUT_STRIP_TRAILING_WHITESPACE)
+    else()
+        STRING(TIMESTAMP ${RESULT} "%Y-%m-%d" UTC)
+    endif()
 ENDMACRO (TODAY)