cpp-httplib/CMakeLists.txt
KTGH ec00fe5d5b
Use git to get full project version (#519)
This gets us the full version (aka with the patch version), instead of
just major and minor version from user agent.

Falls back to the user agent if it fails.
2020-06-10 18:23:45 -04:00

273 lines
10 KiB
CMake

#[[
Build options:
* HTTPLIB_USE_OPENSSL_IF_AVAILABLE (default on)
* HTTPLIB_USE_ZLIB_IF_AVAILABLE (default on)
* HTTPLIB_REQUIRE_OPENSSL (default off)
* HTTPLIB_REQUIRE_ZLIB (default off)
* HTTPLIB_COMPILE (default off)
-------------------------------------------------------------------------------
After installation with Cmake, a find_package(httplib) is available.
This creates a httplib::httplib target (if found).
It can be linked like so:
target_link_libraries(your_exe httplib::httplib)
The following will build & install for later use.
Linux/macOS:
mkdir -p build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
sudo cmake --build . --target install
Windows:
mkdir build
cd build
cmake ..
runas /user:Administrator "cmake --build . --config Release --target install"
-------------------------------------------------------------------------------
These variables are available after you run find_package(httplib)
* HTTPLIB_HEADER_PATH - this is the full path to the installed header (e.g. /usr/include/httplib.h).
* HTTPLIB_IS_USING_OPENSSL - a bool for if OpenSSL support is enabled.
* HTTPLIB_IS_USING_ZLIB - a bool for if ZLIB support is enabled.
* HTTPLIB_IS_COMPILED - a bool for if the library is compiled, or otherwise header-only.
* HTTPLIB_INCLUDE_DIR - the root path to httplib's header (e.g. /usr/include).
* HTTPLIB_LIBRARY - the full path to the library if compiled (e.g. /usr/lib/libhttplib.so).
* HTTPLIB_VERSION - the project's version string.
* HTTPLIB_FOUND - a bool for if the target was found.
Want to use precompiled headers (Cmake feature since v3.16)?
It's as simple as doing the following (before linking):
target_precompile_headers(httplib::httplib INTERFACE "${HTTPLIB_HEADER_PATH}")
-------------------------------------------------------------------------------
FindPython3 requires Cmake v3.12
]]
cmake_minimum_required(VERSION 3.12.0 FATAL_ERROR)
# Gets the latest tag as a string like "v0.6.6"
# Can silently fail if git isn't on the system
execute_process(COMMAND git describe --tags --abbrev=0
OUTPUT_VARIABLE _raw_version_string
ERROR_VARIABLE _git_tag_error
)
# execute_process can fail silenty, so check for an error
# if there was an error, just use the user agent as a version
if(_git_tag_error)
message(WARNING "cpp-httplib failed to find the latest git tag, falling back to using user agent as the version.")
# Get the user agent and use it as a version
# This gets the string with the user agent from the header.
# This is so the maintainer doesn't actually need to update this manually.
file(STRINGS httplib.h _raw_version_string REGEX "User\-Agent.*cpp\-httplib/([0-9]+\.?)+")
endif()
# Needed since git tags have "v" prefixing them.
# Also used if the fallback to user agent string is being used.
string(REGEX MATCH "([0-9]+\\.?)+" _httplib_version "${_raw_version_string}")
project(httplib VERSION ${_httplib_version} LANGUAGES CXX)
# Change as needed to set an OpenSSL minimum version.
# This is used in the installed Cmake config file.
set(_HTTPLIB_OPENSSL_MIN_VER "1.1.1")
# Allow for a build to require OpenSSL to pass, instead of just being optional
option(HTTPLIB_REQUIRE_OPENSSL "Requires OpenSSL to be found & linked, or fails build." OFF)
option(HTTPLIB_REQUIRE_ZLIB "Requires ZLIB to be found & linked, or fails build." OFF)
# Allow for a build to casually enable OpenSSL/ZLIB support, but silenty continue if not found.
# Make these options so their automatic use can be specifically disabled (as needed)
option(HTTPLIB_USE_OPENSSL_IF_AVAILABLE "Uses OpenSSL (if available) to enable HTTPS support." ON)
option(HTTPLIB_USE_ZLIB_IF_AVAILABLE "Uses ZLIB (if available) to enable compression support." ON)
# Lets you compile the program as a regular library instead of header-only
option(HTTPLIB_COMPILE "If ON, uses a Python script to split the header into a compilable header & source file (requires Python v3)." OFF)
# Defaults to static library
option(BUILD_SHARED_LIBS "Build the library as a shared library instead of static. Has no effect if using header-only." OFF)
if (BUILD_SHARED_LIBS AND WIN32 AND HTTPLIB_COMPILE)
# Necessary for Windows if building shared libs
# See https://stackoverflow.com/a/40743080
set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
endif()
# Threads needed for <thread> on some systems, and for <pthread.h> on Linux
find_package(Threads REQUIRED)
# Since Cmake v3.11, Crypto & SSL became optional when not specified as COMPONENTS.
if(HTTPLIB_REQUIRE_OPENSSL)
find_package(OpenSSL ${_HTTPLIB_OPENSSL_MIN_VER} COMPONENTS Crypto SSL REQUIRED)
elseif(HTTPLIB_USE_OPENSSL_IF_AVAILABLE)
find_package(OpenSSL ${_HTTPLIB_OPENSSL_MIN_VER} COMPONENTS Crypto SSL QUIET)
endif()
if(HTTPLIB_REQUIRE_ZLIB)
find_package(ZLIB REQUIRED)
elseif(HTTPLIB_USE_ZLIB_IF_AVAILABLE)
find_package(ZLIB QUIET)
endif()
# Used for default, common dirs that the end-user can change (if needed)
# like CMAKE_INSTALL_INCLUDEDIR or CMAKE_INSTALL_DATADIR
include(GNUInstallDirs)
if(HTTPLIB_COMPILE)
# Put the split script into the build dir
configure_file(split.py "${CMAKE_CURRENT_BINARY_DIR}/split.py"
COPYONLY
)
# Needs to be in the same dir as the python script
configure_file(httplib.h "${CMAKE_CURRENT_BINARY_DIR}/httplib.h"
COPYONLY
)
# Used outside of this if-else
set(_INTERFACE_OR_PUBLIC PUBLIC)
# Brings in the Python3_EXECUTABLE path we can use.
find_package(Python3 REQUIRED)
# Actually split the file
# Keeps the output in the build dir to not pollute the main dir
execute_process(COMMAND ${Python3_EXECUTABLE} "${CMAKE_CURRENT_BINARY_DIR}/split.py"
WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
ERROR_VARIABLE _httplib_split_error
)
if(_httplib_split_error)
message(FATAL_ERROR "Failed when trying to split Cpp-httplib with the Python script.\n${_httplib_split_error}")
endif()
# split.py puts output in "out"
set(_httplib_build_includedir "${CMAKE_CURRENT_BINARY_DIR}/out")
# This will automatically be either static or shared based on the value of BUILD_SHARED_LIBS
add_library(${PROJECT_NAME} "${_httplib_build_includedir}/httplib.cc")
target_sources(${PROJECT_NAME}
PUBLIC
$<BUILD_INTERFACE:${_httplib_build_includedir}/httplib.h>
$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/httplib.h>
)
else()
# This is for header-only.
set(_INTERFACE_OR_PUBLIC INTERFACE)
add_library(${PROJECT_NAME} INTERFACE)
set(_httplib_build_includedir "${CMAKE_CURRENT_SOURCE_DIR}")
endif()
# Lets you address the target with httplib::httplib
# Only useful if building in-tree, versus using it from an installation.
add_library(${PROJECT_NAME}::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
# Might be missing some, but this list is somewhat comprehensive
target_compile_features(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
cxx_std_11
cxx_nullptr
cxx_lambdas
cxx_override
cxx_defaulted_functions
cxx_attribute_deprecated
cxx_auto_type
cxx_decltype
cxx_deleted_functions
cxx_range_for
cxx_sizeof_member
)
target_include_directories(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
$<BUILD_INTERFACE:${_httplib_build_includedir}>
$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
)
# Always require threads
target_link_libraries(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
Threads::Threads
)
# We check for the target when using IF_AVAILABLE since it's possible we didn't find it.
if(HTTPLIB_USE_OPENSSL_IF_AVAILABLE AND TARGET OpenSSL::SSL AND TARGET OpenSSL::Crypto OR HTTPLIB_REQUIRE_OPENSSL)
target_link_libraries(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
OpenSSL::SSL OpenSSL::Crypto
)
target_compile_definitions(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
CPPHTTPLIB_OPENSSL_SUPPORT
)
set(HTTPLIB_IS_USING_OPENSSL TRUE)
else()
set(HTTPLIB_IS_USING_OPENSSL FALSE)
endif()
# We check for the target when using IF_AVAILABLE since it's possible we didn't find it.
if(HTTPLIB_USE_ZLIB_IF_AVAILABLE AND TARGET ZLIB::ZLIB OR HTTPLIB_REQUIRE_ZLIB)
target_link_libraries(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
ZLIB::ZLIB
)
target_compile_definitions(${PROJECT_NAME} ${_INTERFACE_OR_PUBLIC}
CPPHTTPLIB_ZLIB_SUPPORT
)
set(HTTPLIB_IS_USING_ZLIB TRUE)
else()
set(HTTPLIB_IS_USING_ZLIB FALSE)
endif()
# Cmake's find_package search path is different based on the system
# See https://cmake.org/cmake/help/latest/command/find_package.html for the list
if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
set(_TARGET_INSTALL_CMAKEDIR "${CMAKE_INSTALL_PREFIX}/cmake/${PROJECT_NAME}")
else()
# On Non-Windows, it should be /usr/lib/cmake/<name>/<name>Config.cmake
# NOTE: This may or may not work for macOS...
set(_TARGET_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}")
endif()
include(CMakePackageConfigHelpers)
# Configures the meta-file httplibConfig.cmake.in to replace variables with paths/values/etc.
configure_package_config_file("${PROJECT_NAME}Config.cmake.in"
"${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
INSTALL_DESTINATION "${_TARGET_INSTALL_CMAKEDIR}"
# Passes the includedir install path
PATH_VARS CMAKE_INSTALL_FULL_INCLUDEDIR
# There aren't any components, so don't use the macro
NO_CHECK_REQUIRED_COMPONENTS_MACRO
)
if(HTTPLIB_COMPILE)
write_basic_package_version_file("${PROJECT_NAME}ConfigVersion.cmake"
# Example: if you find_package(httplib 0.5.4)
# then anything >= 0.5 and <= 1.0 is accepted
COMPATIBILITY SameMajorVersion
)
else()
write_basic_package_version_file("${PROJECT_NAME}ConfigVersion.cmake"
# Example: if you find_package(httplib 0.5.4)
# then anything >= 0.5 and <= 1.0 is accepted
COMPATIBILITY SameMajorVersion
# Tells Cmake that it's a header-only lib
# Mildly useful for end-users :)
ARCH_INDEPENDENT
)
endif()
# Creates the export httplibTargets.cmake
# This is strictly what holds compilation requirements
# and linkage information (doesn't find deps though).
install(TARGETS ${PROJECT_NAME}
EXPORT httplibTargets
LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
)
install(FILES "${_httplib_build_includedir}/httplib.h" DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
install(FILES
"${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
"${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
DESTINATION ${_TARGET_INSTALL_CMAKEDIR}
)
# NOTE: This path changes depending on if it's on Windows or Linux
install(EXPORT httplibTargets
# Puts the targets into the httplib namespace
# So this makes httplib::httplib linkable after doing find_package(httplib)
NAMESPACE ${PROJECT_NAME}::
DESTINATION ${_TARGET_INSTALL_CMAKEDIR}
)