1# - Returns a version string from Git
2#
3# These functions force a re-configure on each git commit so that you can
4# trust the values of the variables in your build system.
5#
6#  get_git_head_revision(<refspecvar> <hashvar> [<additional arguments to git describe> ...])
7#
8# Returns the refspec and sha hash of the current head revision
9#
10#  git_describe(<var> [<additional arguments to git describe> ...])
11#
12# Returns the results of git describe on the source tree, and adjusting
13# the output so that it tests false if an error occurs.
14#
15#  git_get_exact_tag(<var> [<additional arguments to git describe> ...])
16#
17# Returns the results of git describe --exact-match on the source tree,
18# and adjusting the output so that it tests false if there was no exact
19# matching tag.
20#
21# Requires CMake 2.6 or newer (uses the 'function' command)
22#
23# Original Author:
24# 2009-2010 Ryan Pavlik <rpavlik@iastate.edu> <abiryan@ryand.net>
25# http://academic.cleardefinition.com
26# Iowa State University HCI Graduate Program/VRAC
27#
28# Copyright Iowa State University 2009-2010.
29# Distributed under the Boost Software License, Version 1.0.
30# (See accompanying file LICENSE_1_0.txt or copy at
31# http://www.boost.org/LICENSE_1_0.txt)
32
33if(__get_git_revision_description)
34	return()
35endif()
36set(__get_git_revision_description YES)
37
38# We must run the following at "include" time, not at function call time,
39# to find the path to this module rather than the path to a calling list file
40get_filename_component(_gitdescmoddir ${CMAKE_CURRENT_LIST_FILE} PATH)
41
42function(get_git_head_revision _refspecvar _hashvar)
43	set(GIT_PARENT_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
44	set(GIT_DIR "${GIT_PARENT_DIR}/.git")
45	while(NOT EXISTS "${GIT_DIR}")	# .git dir not found, search parent directories
46		set(GIT_PREVIOUS_PARENT "${GIT_PARENT_DIR}")
47		get_filename_component(GIT_PARENT_DIR ${GIT_PARENT_DIR} PATH)
48		if(GIT_PARENT_DIR STREQUAL GIT_PREVIOUS_PARENT)
49			# We have reached the root directory, we are not in git
50			set(${_refspecvar} "GITDIR-NOTFOUND" PARENT_SCOPE)
51			set(${_hashvar} "GITDIR-NOTFOUND" PARENT_SCOPE)
52			return()
53		endif()
54		set(GIT_DIR "${GIT_PARENT_DIR}/.git")
55	endwhile()
56	# check if this is a submodule
57	if(NOT IS_DIRECTORY ${GIT_DIR})
58		file(READ ${GIT_DIR} submodule)
59		string(REGEX REPLACE "gitdir: (.*)\n$" "\\1" GIT_DIR_RELATIVE ${submodule})
60		get_filename_component(SUBMODULE_DIR ${GIT_DIR} PATH)
61		get_filename_component(GIT_DIR ${SUBMODULE_DIR}/${GIT_DIR_RELATIVE} ABSOLUTE)
62	endif()
63	set(GIT_DATA "${CMAKE_CURRENT_BINARY_DIR}/CMakeFiles/git-data")
64	if(NOT EXISTS "${GIT_DATA}")
65		file(MAKE_DIRECTORY "${GIT_DATA}")
66	endif()
67
68	if(NOT EXISTS "${GIT_DIR}/HEAD")
69		return()
70	endif()
71	set(HEAD_FILE "${GIT_DATA}/HEAD")
72	configure_file("${GIT_DIR}/HEAD" "${HEAD_FILE}" COPYONLY)
73
74	configure_file("${_gitdescmoddir}/GetGitRevisionDescription.cmake.in"
75		"${GIT_DATA}/grabRef.cmake"
76		@ONLY)
77	include("${GIT_DATA}/grabRef.cmake")
78
79	set(${_refspecvar} "${HEAD_REF}" PARENT_SCOPE)
80	set(${_hashvar} "${HEAD_HASH}" PARENT_SCOPE)
81endfunction()
82
83function(git_describe _var)
84	if(NOT GIT_FOUND)
85		find_package(Git QUIET)
86	endif()
87	get_git_head_revision(refspec hash)
88	if(NOT GIT_FOUND)
89		set(${_var} "GIT-NOTFOUND" PARENT_SCOPE)
90		return()
91	endif()
92	if(NOT hash)
93		set(${_var} "HEAD-HASH-NOTFOUND" PARENT_SCOPE)
94		return()
95	endif()
96
97	# TODO sanitize
98	#if((${ARGN}" MATCHES "&&") OR
99	#	(ARGN MATCHES "||") OR
100	#	(ARGN MATCHES "\\;"))
101	#	message("Please report the following error to the project!")
102	#	message(FATAL_ERROR "Looks like someone's doing something nefarious with git_describe! Passed arguments ${ARGN}")
103	#endif()
104
105	#message(STATUS "Arguments to execute_process: ${ARGN}")
106
107	execute_process(COMMAND
108		"${GIT_EXECUTABLE}"
109		describe
110		${hash}
111		${ARGN}
112		WORKING_DIRECTORY
113		"${CMAKE_CURRENT_SOURCE_DIR}"
114		RESULT_VARIABLE
115		res
116		OUTPUT_VARIABLE
117		out
118		ERROR_QUIET
119		OUTPUT_STRIP_TRAILING_WHITESPACE)
120	if(NOT res EQUAL 0)
121		set(out "${out}-${res}-NOTFOUND")
122	endif()
123
124	set(${_var} "${out}" PARENT_SCOPE)
125endfunction()
126
127function(git_get_exact_tag _var)
128	git_describe(out --exact-match ${ARGN})
129	set(${_var} "${out}" PARENT_SCOPE)
130endfunction()
131