Skip to content

Commit 47244c7

Browse files
bodhinandachbodhinandach
authored
🔧 revert accidental delete
1 parent 27f94fd commit 47244c7

File tree

1 file changed

+314
-0
lines changed

1 file changed

+314
-0
lines changed

‎cmake/git_watcher.cmake‎

Lines changed: 314 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,314 @@
1+
# git_watcher.cmake
2+
# https://raw.githubusercontent.com/andrew-hardin/cmake-git-version-tracking/master/git_watcher.cmake
3+
#
4+
# Released under the MIT License.
5+
# https://raw.githubusercontent.com/andrew-hardin/cmake-git-version-tracking/master/LICENSE
6+
7+
8+
# This file defines a target that monitors the state of a git repo.
9+
# If the state changes (e.g. a commit is made), then a file gets reconfigured.
10+
# Here are the primary variables that control script behavior:
11+
#
12+
# PRE_CONFIGURE_FILE (REQUIRED)
13+
# -- The path to the file that'll be configured.
14+
#
15+
# POST_CONFIGURE_FILE (REQUIRED)
16+
# -- The path to the configured PRE_CONFIGURE_FILE.
17+
#
18+
# GIT_STATE_FILE (OPTIONAL)
19+
# -- The path to the file used to store the previous build's git state.
20+
# Defaults to the current binary directory.
21+
#
22+
# GIT_WORKING_DIR (OPTIONAL)
23+
# -- The directory from which git commands will be run.
24+
# Defaults to the directory with the top level CMakeLists.txt.
25+
#
26+
# GIT_EXECUTABLE (OPTIONAL)
27+
# -- The path to the git executable. It'll automatically be set if the
28+
# user doesn't supply a path.
29+
#
30+
# DESIGN
31+
# - This script was designed similar to a Python application
32+
# with a Main() function. I wanted to keep it compact to
33+
# simplify "copy + paste" usage.
34+
#
35+
# - This script is invoked under two CMake contexts:
36+
# 1. Configure time (when build files are created).
37+
# 2. Build time (called via CMake -P).
38+
# The first invocation is what registers the script to
39+
# be executed at build time.
40+
#
41+
# MODIFICATIONS
42+
# You may wish to track other git properties like when the last
43+
# commit was made. There are two sections you need to modify,
44+
# and they're tagged with a ">>>" header.
45+
46+
# Short hand for converting paths to absolute.
47+
macro(PATH_TO_ABSOLUTE var_name)
48+
get_filename_component(${var_name} "${${var_name}}" ABSOLUTE)
49+
endmacro()
50+
51+
# Check that a required variable is set.
52+
macro(CHECK_REQUIRED_VARIABLE var_name)
53+
if(NOT DEFINED ${var_name})
54+
message(FATAL_ERROR "The \"${var_name}\" variable must be defined.")
55+
endif()
56+
PATH_TO_ABSOLUTE(${var_name})
57+
endmacro()
58+
59+
# Check that an optional variable is set, or, set it to a default value.
60+
macro(CHECK_OPTIONAL_VARIABLE var_name default_value)
61+
if(NOT DEFINED ${var_name})
62+
set(${var_name} ${default_value})
63+
endif()
64+
PATH_TO_ABSOLUTE(${var_name})
65+
endmacro()
66+
67+
CHECK_REQUIRED_VARIABLE(PRE_CONFIGURE_FILE)
68+
CHECK_REQUIRED_VARIABLE(POST_CONFIGURE_FILE)
69+
CHECK_OPTIONAL_VARIABLE(GIT_STATE_FILE "${CMAKE_BINARY_DIR}/git-state-hash")
70+
CHECK_OPTIONAL_VARIABLE(GIT_WORKING_DIR "${CMAKE_SOURCE_DIR}")
71+
72+
# Check the optional git variable.
73+
# If it's not set, we'll try to find it using the CMake packaging system.
74+
if(NOT DEFINED GIT_EXECUTABLE)
75+
find_package(Git QUIET REQUIRED)
76+
endif()
77+
CHECK_REQUIRED_VARIABLE(GIT_EXECUTABLE)
78+
79+
80+
set(_state_variable_names
81+
GIT_RETRIEVED_STATE
82+
GIT_HEAD_SHA1
83+
GIT_IS_DIRTY
84+
GIT_AUTHOR_NAME
85+
GIT_AUTHOR_EMAIL
86+
GIT_COMMIT_DATE_ISO8601
87+
GIT_COMMIT_SUBJECT
88+
GIT_COMMIT_BODY
89+
GIT_DESCRIBE
90+
# >>>
91+
# 1. Add the name of the additional git variable you're interested in monitoring
92+
# to this list.
93+
)
94+
95+
96+
97+
# Macro: RunGitCommand
98+
# Description: short-hand macro for calling a git function. Outputs are the
99+
# "exit_code" and "output" variables.
100+
macro(RunGitCommand)
101+
execute_process(COMMAND
102+
"${GIT_EXECUTABLE}" ${ARGV}
103+
WORKING_DIRECTORY "${_working_dir}"
104+
RESULT_VARIABLE exit_code
105+
OUTPUT_VARIABLE output
106+
ERROR_QUIET
107+
OUTPUT_STRIP_TRAILING_WHITESPACE)
108+
if(NOT exit_code EQUAL 0)
109+
set(ENV{GIT_RETRIEVED_STATE} "false")
110+
endif()
111+
endmacro()
112+
113+
114+
115+
# Function: GetGitState
116+
# Description: gets the current state of the git repo.
117+
# Args:
118+
# _working_dir (in) string; the directory from which git commands will be executed.
119+
function(GetGitState _working_dir)
120+
121+
# This is an error code that'll be set to FALSE if the
122+
# RunGitCommand ever returns a non-zero exit code.
123+
set(ENV{GIT_RETRIEVED_STATE} "true")
124+
125+
# Get whether or not the working tree is dirty.
126+
RunGitCommand(status --porcelain)
127+
if(NOT exit_code EQUAL 0)
128+
set(ENV{GIT_IS_DIRTY} "false")
129+
else()
130+
if(NOT "${output}" STREQUAL "")
131+
set(ENV{GIT_IS_DIRTY} "true")
132+
else()
133+
set(ENV{GIT_IS_DIRTY} "false")
134+
endif()
135+
endif()
136+
137+
# There's a long list of attributes grabbed from git show.
138+
set(object HEAD)
139+
RunGitCommand(show -s "--format=%H" ${object})
140+
if(exit_code EQUAL 0)
141+
set(ENV{GIT_HEAD_SHA1} ${output})
142+
endif()
143+
144+
RunGitCommand(show -s "--format=%an" ${object})
145+
if(exit_code EQUAL 0)
146+
set(ENV{GIT_AUTHOR_NAME} "${output}")
147+
endif()
148+
149+
RunGitCommand(show -s "--format=%ae" ${object})
150+
if(exit_code EQUAL 0)
151+
set(ENV{GIT_AUTHOR_EMAIL} "${output}")
152+
endif()
153+
154+
RunGitCommand(show -s "--format=%ci" ${object})
155+
if(exit_code EQUAL 0)
156+
set(ENV{GIT_COMMIT_DATE_ISO8601} "${output}")
157+
endif()
158+
159+
RunGitCommand(show -s "--format=%s" ${object})
160+
if(exit_code EQUAL 0)
161+
# Escape quotes
162+
string(REPLACE "\"" "\\\"" output "${output}")
163+
set(ENV{GIT_COMMIT_SUBJECT} "${output}")
164+
endif()
165+
166+
RunGitCommand(show -s "--format=%b" ${object})
167+
if(exit_code EQUAL 0)
168+
if(output)
169+
# Escape quotes
170+
string(REPLACE "\"" "\\\"" output "${output}")
171+
# Escape line breaks in the commit message.
172+
string(REPLACE "\r\n" "\\r\\n\\\r\n" safe "${output}")
173+
if(safe STREQUAL output)
174+
# Didn't have windows lines - try unix lines.
175+
string(REPLACE "\n" "\\n\\\n" safe "${output}")
176+
endif()
177+
else()
178+
# There was no commit body - set the safe string to empty.
179+
set(safe "")
180+
endif()
181+
set(ENV{GIT_COMMIT_BODY} "\"${safe}\"")
182+
else()
183+
set(ENV{GIT_COMMIT_BODY} "\"\"") # empty string.
184+
endif()
185+
186+
# Get output of git describe
187+
RunGitCommand(describe --always ${object})
188+
if(NOT exit_code EQUAL 0)
189+
set(ENV{GIT_DESCRIBE} "unknown")
190+
else()
191+
set(ENV{GIT_DESCRIBE} "${output}")
192+
endif()
193+
194+
# >>>
195+
# 2. Additional git properties can be added here via the
196+
# "execute_process()" command. Be sure to set them in
197+
# the environment using the same variable name you added
198+
# to the "_state_variable_names" list.
199+
200+
endfunction()
201+
202+
203+
204+
# Function: GitStateChangedAction
205+
# Description: this function is executed when the state of the git
206+
# repository changes (e.g. a commit is made).
207+
function(GitStateChangedAction)
208+
foreach(var_name ${_state_variable_names})
209+
set(${var_name} $ENV{${var_name}})
210+
endforeach()
211+
configure_file("${PRE_CONFIGURE_FILE}" "${POST_CONFIGURE_FILE}" @ONLY)
212+
endfunction()
213+
214+
215+
216+
# Function: HashGitState
217+
# Description: loop through the git state variables and compute a unique hash.
218+
# Args:
219+
# _state (out) string; a hash computed from the current git state.
220+
function(HashGitState _state)
221+
set(ans "")
222+
foreach(var_name ${_state_variable_names})
223+
string(SHA256 ans "${ans}$ENV{${var_name}}")
224+
endforeach()
225+
set(${_state} ${ans} PARENT_SCOPE)
226+
endfunction()
227+
228+
229+
230+
# Function: CheckGit
231+
# Description: check if the git repo has changed. If so, update the state file.
232+
# Args:
233+
# _working_dir (in) string; the directory from which git commands will be ran.
234+
# _state_changed (out) bool; whether or no the state of the repo has changed.
235+
function(CheckGit _working_dir _state_changed)
236+
237+
# Get the current state of the repo.
238+
GetGitState("${_working_dir}")
239+
240+
# Convert that state into a hash that we can compare against
241+
# the hash stored on-disk.
242+
HashGitState(state)
243+
244+
# Issue 14: post-configure file isn't being regenerated.
245+
#
246+
# Update the state to include the SHA256 for the pre-configure file.
247+
# This forces the post-configure file to be regenerated if the
248+
# pre-configure file has changed.
249+
file(SHA256 ${PRE_CONFIGURE_FILE} preconfig_hash)
250+
string(SHA256 state "${preconfig_hash}${state}")
251+
252+
# Check if the state has changed compared to the backup on disk.
253+
if(EXISTS "${GIT_STATE_FILE}")
254+
file(READ "${GIT_STATE_FILE}" OLD_HEAD_CONTENTS)
255+
if(OLD_HEAD_CONTENTS STREQUAL "${state}")
256+
# State didn't change.
257+
set(${_state_changed} "false" PARENT_SCOPE)
258+
return()
259+
endif()
260+
endif()
261+
262+
# The state has changed.
263+
# We need to update the state file on disk.
264+
# Future builds will compare their state to this file.
265+
file(WRITE "${GIT_STATE_FILE}" "${state}")
266+
set(${_state_changed} "true" PARENT_SCOPE)
267+
endfunction()
268+
269+
270+
271+
# Function: SetupGitMonitoring
272+
# Description: this function sets up custom commands that make the build system
273+
# check the state of git before every build. If the state has
274+
# changed, then a file is configured.
275+
function(SetupGitMonitoring)
276+
add_custom_target(check_git
277+
ALL
278+
DEPENDS ${PRE_CONFIGURE_FILE}
279+
BYPRODUCTS
280+
${POST_CONFIGURE_FILE}
281+
${GIT_STATE_FILE}
282+
COMMENT "Checking the git repository for changes..."
283+
COMMAND
284+
${CMAKE_COMMAND}
285+
-D_BUILD_TIME_CHECK_GIT=TRUE
286+
-DGIT_WORKING_DIR=${GIT_WORKING_DIR}
287+
-DGIT_EXECUTABLE=${GIT_EXECUTABLE}
288+
-DGIT_STATE_FILE=${GIT_STATE_FILE}
289+
-DPRE_CONFIGURE_FILE=${PRE_CONFIGURE_FILE}
290+
-DPOST_CONFIGURE_FILE=${POST_CONFIGURE_FILE}
291+
-P "${CMAKE_CURRENT_LIST_FILE}")
292+
endfunction()
293+
294+
295+
296+
# Function: Main
297+
# Description: primary entry-point to the script. Functions are selected based
298+
# on whether it's configure or build time.
299+
function(Main)
300+
if(_BUILD_TIME_CHECK_GIT)
301+
# Check if the repo has changed.
302+
# If so, run the change action.
303+
CheckGit("${GIT_WORKING_DIR}" changed)
304+
if(changed OR NOT EXISTS "${POST_CONFIGURE_FILE}")
305+
GitStateChangedAction()
306+
endif()
307+
else()
308+
# >> Executes at configure time.
309+
SetupGitMonitoring()
310+
endif()
311+
endfunction()
312+
313+
# And off we go...
314+
Main()

0 commit comments

Comments
 (0)