curl/CMake/FindZstd.cmake
Viktor Szakats f66af623cf
cmake: document -D and env build options
Extend `INSTALL-CMAKE` document with the list of available options,
a short description and default values.

The list may not be 100% complete.

There are no component boundaries in CMake, so the line is blurry
between curl options, CMake options, CMake Find modules options.
I included certain CMake options that seemed useful, and/or have
dedicated use withing curl's CMake source. But, all CMake built-in
options are usable, as documented upstream in CMake.

The naming of the options has a heritage and the inconsistencies with
it, including a lack of clear namespace. This may be subject to future
updates, also after figuring out which name has special meaning within
CMake and/or CMake projects out of unwritten convention or something
more tangible.

CMake allows to initialize any internal variable via `-D`. This may be
useful to pre-initialize/override feature check results. The list
doesn't contain these, and they remain officially undocumented.

Also:
- make adjustments to keep the spellchecker happy.
- retrofit description changes to the cmake sources.
- stop documenting deprecated `Find*` variables.

Reported-by: Daniel Stenberg
Fixes https://github.com/curl/curl/discussions/14885
Closes #15388
2024-10-24 23:06:40 +02:00

100 lines
3.4 KiB
CMake

#***************************************************************************
# _ _ ____ _
# Project ___| | | | _ \| |
# / __| | | | |_) | |
# | (__| |_| | _ <| |___
# \___|\___/|_| \_\_____|
#
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at https://curl.se/docs/copyright.html.
#
# You may opt to use, copy, modify, merge, publish, distribute and/or sell
# copies of the Software, and permit persons to whom the Software is
# furnished to do so, under the terms of the COPYING file.
#
# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
# KIND, either express or implied.
#
# SPDX-License-Identifier: curl
#
###########################################################################
# Find the zstd library
#
# Input variables:
#
# - `ZSTD_INCLUDE_DIR`: The zstd include directory.
# - `ZSTD_LIBRARY`: Path to `zstd` library.
#
# Result variables:
#
# - `ZSTD_FOUND`: System has zstd.
# - `ZSTD_INCLUDE_DIRS`: The zstd include directories.
# - `ZSTD_LIBRARIES`: The zstd library names.
# - `ZSTD_VERSION`: Version of zstd.
if(DEFINED Zstd_INCLUDE_DIR AND NOT DEFINED ZSTD_INCLUDE_DIR)
message(WARNING "Zstd_INCLUDE_DIR is deprecated, use ZSTD_INCLUDE_DIR instead.")
set(ZSTD_INCLUDE_DIR "${Zstd_INCLUDE_DIR}")
endif()
if(DEFINED Zstd_LIBRARY AND NOT DEFINED ZSTD_LIBRARY)
message(WARNING "Zstd_LIBRARY is deprecated, use ZSTD_LIBRARY instead.")
set(ZSTD_LIBRARY "${Zstd_LIBRARY}")
endif()
if(CURL_USE_PKGCONFIG)
find_package(PkgConfig QUIET)
pkg_check_modules(PC_ZSTD "libzstd")
endif()
find_path(ZSTD_INCLUDE_DIR NAMES "zstd.h"
HINTS
${PC_ZSTD_INCLUDEDIR}
${PC_ZSTD_INCLUDE_DIRS}
)
find_library(ZSTD_LIBRARY NAMES "zstd"
HINTS
${PC_ZSTD_LIBDIR}
${PC_ZSTD_LIBRARY_DIRS}
)
if(PC_ZSTD_VERSION)
set(ZSTD_VERSION ${PC_ZSTD_VERSION})
elseif(ZSTD_INCLUDE_DIR AND EXISTS "${ZSTD_INCLUDE_DIR}/zstd.h")
set(_version_regex1 "#[\t ]*define[ \t]+ZSTD_VERSION_MAJOR[ \t]+([0-9]+).*")
set(_version_regex2 "#[\t ]*define[ \t]+ZSTD_VERSION_MINOR[ \t]+([0-9]+).*")
set(_version_regex3 "#[\t ]*define[ \t]+ZSTD_VERSION_RELEASE[ \t]+([0-9]+).*")
file(STRINGS "${ZSTD_INCLUDE_DIR}/zstd.h" _version_str1 REGEX "${_version_regex1}")
file(STRINGS "${ZSTD_INCLUDE_DIR}/zstd.h" _version_str2 REGEX "${_version_regex2}")
file(STRINGS "${ZSTD_INCLUDE_DIR}/zstd.h" _version_str3 REGEX "${_version_regex3}")
string(REGEX REPLACE "${_version_regex1}" "\\1" _version_str1 "${_version_str1}")
string(REGEX REPLACE "${_version_regex2}" "\\1" _version_str2 "${_version_str2}")
string(REGEX REPLACE "${_version_regex3}" "\\1" _version_str3 "${_version_str3}")
set(ZSTD_VERSION "${_version_str1}.${_version_str2}.${_version_str3}")
unset(_version_regex1)
unset(_version_regex2)
unset(_version_regex3)
unset(_version_str1)
unset(_version_str2)
unset(_version_str3)
endif()
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(Zstd
REQUIRED_VARS
ZSTD_INCLUDE_DIR
ZSTD_LIBRARY
VERSION_VAR
ZSTD_VERSION
)
if(ZSTD_FOUND)
set(ZSTD_INCLUDE_DIRS ${ZSTD_INCLUDE_DIR})
set(ZSTD_LIBRARIES ${ZSTD_LIBRARY})
endif()
mark_as_advanced(ZSTD_INCLUDE_DIR ZSTD_LIBRARY)