From 070ff889d2dc757ca909cf545639a3cbe1e0bc7f Mon Sep 17 00:00:00 2001
From: Riccardo Spagni <ric@spagni.net>
Date: Mon, 15 Sep 2014 23:01:50 +0200
Subject: [PATCH] More robust versioning in CMake, plus comments

---
 src/version.cmake | 75 +++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 62 insertions(+), 13 deletions(-)

diff --git a/src/version.cmake b/src/version.cmake
index e851cdf01..0d1e52a25 100644
--- a/src/version.cmake
+++ b/src/version.cmake
@@ -1,30 +1,79 @@
+# Copyright (c) 2014, The Monero Project
+# 
+# All rights reserved.
+# 
+# Redistribution and use in source and binary forms, with or without modification, are
+# permitted provided that the following conditions are met:
+# 
+# 1. Redistributions of source code must retain the above copyright notice, this list of
+#    conditions and the following disclaimer.
+# 
+# 2. Redistributions in binary form must reproduce the above copyright notice, this list
+#    of conditions and the following disclaimer in the documentation and/or other
+#    materials provided with the distribution.
+# 
+# 3. Neither the name of the copyright holder nor the names of its contributors may be
+#    used to endorse or promote products derived from this software without specific
+#    prior written permission.
+# 
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# 
+# Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+
+# Check what commit we're on
 execute_process(COMMAND "${GIT}" rev-parse --short HEAD RESULT_VARIABLE RET OUTPUT_VARIABLE COMMIT OUTPUT_STRIP_TRAILING_WHITESPACE)
 
 if(RET)
+	# Something went wrong, set the version tag to -unknown
+	
     message(WARNING "Cannot determine current commit. Make sure that you are building either from a Git working tree or from a source archive.")
     set(VERSIONTAG "unknown")
     configure_file("src/version.h.in" "${TO}")
 else()
 	message(STATUS "You are currently on commit ${COMMIT}")
+	
+	# Get all the tags
 	execute_process(COMMAND "${GIT}" show-ref --tags -d --abbrev RESULT_VARIABLE RET OUTPUT_VARIABLE TAGGEDCOMMITOUT OUTPUT_STRIP_TRAILING_WHITESPACE)
 	
-	string(REPLACE " refs/" "\n" TAGGEDCOMMITOUT2 ${TAGGEDCOMMITOUT})
-	string(REPLACE "\n" ";" TAGGEDCOMMITLIST ${TAGGEDCOMMITOUT2})
-	list(GET TAGGEDCOMMITLIST -2 TAGGEDCOMMIT)
+	# Make sure we actually got some tags
+	string(LENGTH ${TAGGEDCOMMITOUT} TLEN)
 	
-	if(RET OR NOT TAGGEDCOMMIT)
+	if(RET OR TLEN LESS 5)
 	    message(WARNING "Cannot determine most recent tag. Make sure that you are building either from a Git working tree or from a source archive.")
-	    set(VERSIONTAG "${COMMIT}")
+	    set(VERSIONTAG "${COMMIT}")		
 	else()
-		message(STATUS "The most recent tag was at ${TAGGEDCOMMIT}")
-		if(${COMMIT} MATCHES ${TAGGEDCOMMIT})
-			message(STATUS "You are building a tagged release")
-		    set(VERSIONTAG "release")
+		# Replace a bunch of things so we end up with a semi-colon separated list
+		string(REPLACE " refs/" "\n" TAGGEDCOMMITOUT2 ${TAGGEDCOMMITOUT})
+		string(REPLACE "\n" ";" TAGGEDCOMMITLIST ${TAGGEDCOMMITOUT2})
+		
+		# Grab the second-last item in the list, as that will be the hash of our most recent commit
+		list(GET TAGGEDCOMMITLIST -2 TAGGEDCOMMIT)
+
+		if(NOT TAGGEDCOMMIT)
+			message(WARNING "Cannot determine most recent tag. Make sure that you are building either from a Git working tree or from a source archive.")
+			set(VERSIONTAG "${COMMIT}")
 		else()
-			message(STATUS "You are ahead or behind of a tagged release")
-		    set(VERSIONTAG "${COMMIT}")
-		endif()
-	endif()	    
+			message(STATUS "The most recent tag was at ${TAGGEDCOMMIT}")
+			
+			# Check if we're building that tagged commit or a different one
+			if(${COMMIT} MATCHES ${TAGGEDCOMMIT})
+				message(STATUS "You are building a tagged release")
+				set(VERSIONTAG "release")
+			else()
+				message(STATUS "You are ahead or behind of a tagged release")
+				set(VERSIONTAG "${COMMIT}")
+			endif()
+		endif()	    
+
+	endif()
 
     configure_file("src/version.h.in" "${TO}")
 endif()
\ No newline at end of file