PokemonScriptTester/git_watcher.cmake

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# git_watcher.cmake
# https://raw.githubusercontent.com/andrew-hardin/cmake-git-version-tracking/master/git_watcher.cmake
#
# Released under the MIT License.
# https://raw.githubusercontent.com/andrew-hardin/cmake-git-version-tracking/master/LICENSE
# This file defines a target that monitors the state of a git repo.
# If the state changes (e.g. a commit is made), then a file gets reconfigured.
# Here are the primary variables that control script behavior:
#
# PRE_CONFIGURE_FILE (REQUIRED)
# -- The path to the file that'll be configured.
#
# POST_CONFIGURE_FILE (REQUIRED)
# -- The path to the configured PRE_CONFIGURE_FILE.
#
# GIT_STATE_FILE (OPTIONAL)
# -- The path to the file used to store the previous build's git state.
# Defaults to the current binary directory.
#
# GIT_WORKING_DIR (OPTIONAL)
# -- The directory from which git commands will be run.
# Defaults to the directory with the top level CMakeLists.txt.
#
# GIT_EXECUTABLE (OPTIONAL)
# -- The path to the git executable. It'll automatically be set if the
# user doesn't supply a path.
#
# GIT_FAIL_IF_NONZERO_EXIT (optional)
# -- Raise a FATAL_ERROR if any of the git commands return a non-zero
# exit code. This is set to TRUE by default. You can set this to FALSE
# if you'd like the build to continue even if a git command fails.
#
# DESIGN
# - This script was designed similar to a Python application
# with a Main() function. I wanted to keep it compact to
# simplify "copy + paste" usage.
#
# - This script is invoked under two CMake contexts:
# 1. Configure time (when build files are created).
# 2. Build time (called via CMake -P).
# The first invocation is what registers the script to
# be executed at build time.
#
# MODIFICATIONS
# You may wish to track other git properties like when the last
# commit was made. There are two sections you need to modify,
# and they're tagged with a ">>>" header.
# Short hand for converting paths to absolute.
macro(PATH_TO_ABSOLUTE var_name)
get_filename_component(${var_name} "${${var_name}}" ABSOLUTE)
endmacro()
# Check that a required variable is set.
macro(CHECK_REQUIRED_VARIABLE var_name)
if(NOT DEFINED ${var_name})
message(FATAL_ERROR "The \"${var_name}\" variable must be defined.")
endif()
PATH_TO_ABSOLUTE(${var_name})
endmacro()
# Check that an optional variable is set, or, set it to a default value.
macro(CHECK_OPTIONAL_VARIABLE_NOPATH var_name default_value)
if(NOT DEFINED ${var_name})
set(${var_name} ${default_value})
endif()
endmacro()
# Check that an optional variable is set, or, set it to a default value.
# Also converts that path to an abspath.
macro(CHECK_OPTIONAL_VARIABLE var_name default_value)
CHECK_OPTIONAL_VARIABLE_NOPATH(${var_name} ${default_value})
PATH_TO_ABSOLUTE(${var_name})
endmacro()
CHECK_REQUIRED_VARIABLE(PRE_CONFIGURE_FILE)
CHECK_REQUIRED_VARIABLE(POST_CONFIGURE_FILE)
CHECK_OPTIONAL_VARIABLE(GIT_STATE_FILE "${CMAKE_BINARY_DIR}/git-state-hash")
CHECK_OPTIONAL_VARIABLE(GIT_WORKING_DIR "${CMAKE_SOURCE_DIR}")
CHECK_OPTIONAL_VARIABLE_NOPATH(GIT_FAIL_IF_NONZERO_EXIT TRUE)
# Check the optional git variable.
# If it's not set, we'll try to find it using the CMake packaging system.
if(NOT DEFINED GIT_EXECUTABLE)
find_package(Git QUIET REQUIRED)
endif()
CHECK_REQUIRED_VARIABLE(GIT_EXECUTABLE)
set(_state_variable_names
GIT_RETRIEVED_STATE
GIT_HEAD_SHA1
GIT_IS_DIRTY
GIT_AUTHOR_NAME
GIT_AUTHOR_EMAIL
GIT_COMMIT_DATE_ISO8601
GIT_COMMIT_SUBJECT
GIT_COMMIT_BODY
GIT_DESCRIBE
# >>>
# 1. Add the name of the additional git variable you're interested in monitoring
# to this list.
)
# Macro: RunGitCommand
# Description: short-hand macro for calling a git function. Outputs are the
# "exit_code" and "output" variables.
macro(RunGitCommand)
execute_process(COMMAND
"${GIT_EXECUTABLE}" ${ARGV}
WORKING_DIRECTORY "${_working_dir}"
RESULT_VARIABLE exit_code
OUTPUT_VARIABLE output
ERROR_VARIABLE stderr
OUTPUT_STRIP_TRAILING_WHITESPACE)
if(NOT exit_code EQUAL 0)
set(ENV{GIT_RETRIEVED_STATE} "false")
# Issue 26: git info not properly set
#
# Check if we should fail if any of the exit codes are non-zero.
if(GIT_FAIL_IF_NONZERO_EXIT)
string(REPLACE ";" " " args_with_spaces "${ARGV}")
message(FATAL_ERROR "${stderr} (${GIT_EXECUTABLE} ${args_with_spaces})")
endif()
endif()
endmacro()
# Function: GetGitState
# Description: gets the current state of the git repo.
# Args:
# _working_dir (in) string; the directory from which git commands will be executed.
function(GetGitState _working_dir)
# This is an error code that'll be set to FALSE if the
# RunGitCommand ever returns a non-zero exit code.
set(ENV{GIT_RETRIEVED_STATE} "true")
# Get whether or not the working tree is dirty.
RunGitCommand(status --porcelain)
if(NOT exit_code EQUAL 0)
set(ENV{GIT_IS_DIRTY} "false")
else()
if(NOT "${output}" STREQUAL "")
set(ENV{GIT_IS_DIRTY} "true")
else()
set(ENV{GIT_IS_DIRTY} "false")
endif()
endif()
# There's a long list of attributes grabbed from git show.
set(object HEAD)
RunGitCommand(show -s "--format=%H" ${object})
if(exit_code EQUAL 0)
set(ENV{GIT_HEAD_SHA1} ${output})
endif()
RunGitCommand(show -s "--format=%an" ${object})
if(exit_code EQUAL 0)
set(ENV{GIT_AUTHOR_NAME} "${output}")
endif()
RunGitCommand(show -s "--format=%ae" ${object})
if(exit_code EQUAL 0)
set(ENV{GIT_AUTHOR_EMAIL} "${output}")
endif()
RunGitCommand(show -s "--format=%ci" ${object})
if(exit_code EQUAL 0)
set(ENV{GIT_COMMIT_DATE_ISO8601} "${output}")
endif()
RunGitCommand(show -s "--format=%s" ${object})
if(exit_code EQUAL 0)
# Escape quotes
string(REPLACE "\"" "\\\"" output "${output}")
set(ENV{GIT_COMMIT_SUBJECT} "${output}")
endif()
RunGitCommand(show -s "--format=%b" ${object})
if(exit_code EQUAL 0)
if(output)
# Escape quotes
string(REPLACE "\"" "\\\"" output "${output}")
# Escape line breaks in the commit message.
string(REPLACE "\r\n" "\\r\\n\\\r\n" safe "${output}")
if(safe STREQUAL output)
# Didn't have windows lines - try unix lines.
string(REPLACE "\n" "\\n\\\n" safe "${output}")
endif()
else()
# There was no commit body - set the safe string to empty.
set(safe "")
endif()
set(ENV{GIT_COMMIT_BODY} "\"${safe}\"")
else()
set(ENV{GIT_COMMIT_BODY} "\"\"") # empty string.
endif()
# Get output of git describe
RunGitCommand(describe --always --tags ${object})
if(NOT exit_code EQUAL 0)
set(ENV{GIT_DESCRIBE} "unknown")
else()
set(ENV{GIT_DESCRIBE} "${output}")
endif()
# >>>
# 2. Additional git properties can be added here via the
# "execute_process()" command. Be sure to set them in
# the environment using the same variable name you added
# to the "_state_variable_names" list.
endfunction()
# Function: GitStateChangedAction
# Description: this function is executed when the state of the git
# repository changes (e.g. a commit is made).
function(GitStateChangedAction)
foreach(var_name ${_state_variable_names})
set(${var_name} $ENV{${var_name}})
endforeach()
configure_file("${PRE_CONFIGURE_FILE}" "${POST_CONFIGURE_FILE}" @ONLY)
endfunction()
# Function: HashGitState
# Description: loop through the git state variables and compute a unique hash.
# Args:
# _state (out) string; a hash computed from the current git state.
function(HashGitState _state)
set(ans "")
foreach(var_name ${_state_variable_names})
string(SHA256 ans "${ans}$ENV{${var_name}}")
endforeach()
set(${_state} ${ans} PARENT_SCOPE)
endfunction()
# Function: CheckGit
# Description: check if the git repo has changed. If so, update the state file.
# Args:
# _working_dir (in) string; the directory from which git commands will be ran.
# _state_changed (out) bool; whether or no the state of the repo has changed.
function(CheckGit _working_dir _state_changed)
# Get the current state of the repo.
GetGitState("${_working_dir}")
# Convert that state into a hash that we can compare against
# the hash stored on-disk.
HashGitState(state)
# Issue 14: post-configure file isn't being regenerated.
#
# Update the state to include the SHA256 for the pre-configure file.
# This forces the post-configure file to be regenerated if the
# pre-configure file has changed.
file(SHA256 ${PRE_CONFIGURE_FILE} preconfig_hash)
string(SHA256 state "${preconfig_hash}${state}")
# Check if the state has changed compared to the backup on disk.
if(EXISTS "${GIT_STATE_FILE}")
file(READ "${GIT_STATE_FILE}" OLD_HEAD_CONTENTS)
if(OLD_HEAD_CONTENTS STREQUAL "${state}")
# State didn't change.
set(${_state_changed} "false" PARENT_SCOPE)
return()
endif()
endif()
# The state has changed.
# We need to update the state file on disk.
# Future builds will compare their state to this file.
file(WRITE "${GIT_STATE_FILE}" "${state}")
set(${_state_changed} "true" PARENT_SCOPE)
endfunction()
# Function: SetupGitMonitoring
# Description: this function sets up custom commands that make the build system
# check the state of git before every build. If the state has
# changed, then a file is configured.
function(SetupGitMonitoring)
add_custom_target(check_git
ALL
DEPENDS ${PRE_CONFIGURE_FILE}
BYPRODUCTS
${POST_CONFIGURE_FILE}
${GIT_STATE_FILE}
COMMENT "Checking the git repository for changes..."
COMMAND
${CMAKE_COMMAND}
-D_BUILD_TIME_CHECK_GIT=TRUE
-DGIT_WORKING_DIR=${GIT_WORKING_DIR}
-DGIT_EXECUTABLE=${GIT_EXECUTABLE}
-DGIT_STATE_FILE=${GIT_STATE_FILE}
-DPRE_CONFIGURE_FILE=${PRE_CONFIGURE_FILE}
-DPOST_CONFIGURE_FILE=${POST_CONFIGURE_FILE}
-DGIT_FAIL_IF_NONZERO_EXIT=${GIT_FAIL_IF_NONZERO_EXIT}
-P "${CMAKE_CURRENT_LIST_FILE}")
endfunction()
# Function: Main
# Description: primary entry-point to the script. Functions are selected based
# on whether it's configure or build time.
function(Main)
if(_BUILD_TIME_CHECK_GIT)
# Check if the repo has changed.
# If so, run the change action.
CheckGit("${GIT_WORKING_DIR}" changed)
if(changed OR NOT EXISTS "${POST_CONFIGURE_FILE}")
GitStateChangedAction()
endif()
else()
# >> Executes at configure time.
SetupGitMonitoring()
endif()
endfunction()
# And off we go...
Main()