Files
curl/CMake/FindBrotli.cmake
Viktor Szakats 16f073ef49 cmake: define dependencies as IMPORTED interface targets
Rework the way curl's custom Find modules advertise their properties.

Before this patch, Find modules returned detected dependency properties
(header dirs, libs, libdirs, C flags, etc.) via global variables. curl's
main `CMakeLists.txt` copied their values into global lists, which it
later applied to targets. This solution worked internally, but it was
unsuited for the public, distributed `CURLConfig.cmake` and publishing
curl's Find modules with it, due to polluting the namespace of consumer
projects. It's also impractical to apply the many individual variables
to every targets depending on libcurl.

To allow using Find modules in consumer projects, this patch makes them
define as imported interface targets, named `CURL::<dependency>`. Then
store dependency information as target properties. It avoids namespace
pollution and makes the dependency information apply automatically
to all targets using `CURL::libcurl_static`.

Find modules continue to return `*_FOUND` and `*_VERSION` variables.

For dependencies detected via `pkg-config`, CMake 3.16+ is recommended.
Older CMake versions have a varying degree of support for
propagating/handling library directories. This may cause issues in envs
where dependencies reside in non-system locations and detected via
`pkg-config` (e.g. macOS + Homebrew). Use `CURL_USE_PKGCONFIG=OFF`
to fix these issues. Or upgrade to newer CMake, or link libcurl
dynamically.

Also:
- re-enable `pkg-config` for old cmake `find_library()` integration
  tests.
- make `curlinfo` build after these changes.
- distribute local Find modules.
- export the raw list of lib dependencies via `CURL_LIBRARIES_PRIVATE`.
- `CURLconfig.cmake`: use curl's Find modules to detect dependencies in
  the consumer env.
- add custom property to target property debug function.
- the curl build process no longer modifies `CMAKE_C_FLAGS`.
  Follow-up to e86542038d #17047

Ref: #14930
Ref: https://github.com/libssh2/libssh2/pull/1535
Ref: https://github.com/libssh2/libssh2/pull/1571
Ref: https://github.com/libssh2/libssh2/pull/1581
Ref: https://github.com/libssh2/libssh2/pull/1623

Closes #16973
2025-11-29 01:41:40 +01:00

89 lines
3.1 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 brotli library
#
# Input variables:
#
# - `BROTLI_INCLUDE_DIR`: Absolute path to brotli include directory.
# - `BROTLICOMMON_LIBRARY`: Absolute path to `brotlicommon` library.
# - `BROTLIDEC_LIBRARY`: Absolute path to `brotlidec` library.
#
# Defines:
#
# - `BROTLI_FOUND`: System has brotli.
# - `BROTLI_VERSION`: Version of brotli.
# - `CURL::brotli`: brotli library target.
set(_brotli_pc_requires "libbrotlidec" "libbrotlicommon") # order is significant: brotlidec then brotlicommon
if(CURL_USE_PKGCONFIG AND
NOT DEFINED BROTLI_INCLUDE_DIR AND
NOT DEFINED BROTLICOMMON_LIBRARY AND
NOT DEFINED BROTLIDEC_LIBRARY)
find_package(PkgConfig QUIET)
pkg_check_modules(_brotli ${_brotli_pc_requires})
endif()
if(_brotli_FOUND)
set(Brotli_FOUND TRUE)
set(BROTLI_FOUND TRUE)
set(BROTLI_VERSION ${_brotli_libbrotlicommon_VERSION})
message(STATUS "Found Brotli (via pkg-config): ${_brotli_INCLUDE_DIRS} (found version \"${BROTLI_VERSION}\")")
else()
find_path(BROTLI_INCLUDE_DIR "brotli/decode.h")
find_library(BROTLICOMMON_LIBRARY NAMES "brotlicommon")
find_library(BROTLIDEC_LIBRARY NAMES "brotlidec")
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(Brotli
REQUIRED_VARS
BROTLI_INCLUDE_DIR
BROTLIDEC_LIBRARY
BROTLICOMMON_LIBRARY
)
if(BROTLI_FOUND)
set(_brotli_INCLUDE_DIRS ${BROTLI_INCLUDE_DIR})
set(_brotli_LIBRARIES ${BROTLIDEC_LIBRARY} ${BROTLICOMMON_LIBRARY})
endif()
mark_as_advanced(BROTLI_INCLUDE_DIR BROTLIDEC_LIBRARY BROTLICOMMON_LIBRARY)
endif()
if(BROTLI_FOUND)
if(CMAKE_VERSION VERSION_LESS 3.13)
link_directories(${_brotli_LIBRARY_DIRS})
endif()
if(NOT TARGET CURL::brotli)
add_library(CURL::brotli INTERFACE IMPORTED)
set_target_properties(CURL::brotli PROPERTIES
INTERFACE_LIBCURL_PC_MODULES "${_brotli_pc_requires}"
INTERFACE_COMPILE_OPTIONS "${_brotli_CFLAGS}"
INTERFACE_INCLUDE_DIRECTORIES "${_brotli_INCLUDE_DIRS}"
INTERFACE_LINK_DIRECTORIES "${_brotli_LIBRARY_DIRS}"
INTERFACE_LINK_LIBRARIES "${_brotli_LIBRARIES}")
endif()
endif()