curl/CMake
Viktor Szakats 89043ba906
cmake: drop support for CMake 3.17 and older
Require CMake 3.18 (2020-07-15) or newer, up from 3.7 (2016-11-11)
prior to this patch.

This requirement also applies to the distributed `curl-config.cmake`.

To allow dropping compatibility code maintained for old versions, and to
use features which were unpractical in separate code paths. Also to make
testing, documentation and development easier, CI builds faster due to
CMake performance improvements over time. (e.g. integration tests on
macOS run 8x faster (10 minutes is now under 1.5m) in CI, 2.5x faster on
Windows.)

CMake offers pre-built binaries for major platforms. They work without
an install step, just by unpacking and pointing the cmake command to
them. Making upgrades easy in many cases:
https://cmake.org/download/
https://cmake.org/files/
https://github.com/Kitware/CMake/releases

CMake 3.18 brings these feature as generally available when building or
consuming curl/libcurl:

LTO support, improved performance, `pkg-config` and interface target
support, `OBJECT` target (for faster libcurl builds), modern invocation
with `-S`/`-B` options, better support for custom linker options,
FetchContent, `GnuTLS::GnuTLS` target, `--verbose` and `--install`
options, `CMAKE_GENERATOR` env, last but not least unity mode and Ninja
generator.

For maximum build speed, use:
`-DCMAKE_UNITY_BUILD=ON -DCURL_DROP_UNUSED=ON`

As for deprecations, C++11 is required to build CMake itself, which may
be a limit on some platforms. autotools continues to cover them.

Follow-up to 9bcdfb3809 #20408
Follow-up to a7c974e038 #19902
Follow-up to dfbe035c8b #10161
Discussion: https://github.com/curl/curl/discussions/18704

Closes #20407
2026-03-21 13:24:47 +01:00
..
cmake_uninstall.in.cmake cmake: match filename suffixes with file content 2025-12-20 11:34:27 +01:00
curl-config.in.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
CurlSymbolHiding.cmake build: merge TrackMemory (CURLDEBUG) into debug-enabled option 2026-01-19 18:43:17 +01:00
CurlTests.c badwords: avoid 'simply' 2026-03-10 19:34:06 +01:00
FindBrotli.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindCares.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindGnuTLS.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindGSS.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLDAP.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibbacktrace.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibgsasl.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibidn2.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibpsl.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibrtmp.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibssh.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibssh2.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindLibuv.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindMbedTLS.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindNettle.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindNGHTTP2.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindNGHTTP3.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindNGTCP2.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindQuiche.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindRustls.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindWolfSSL.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
FindZstd.cmake cmake: drop support for CMake 3.17 and older 2026-03-21 13:24:47 +01:00
Macros.cmake cmake: resolve imported targets recursively when generating libcurl.pc 2026-03-16 11:57:56 +01:00
OtherTests.cmake build: check MSG_NOSIGNAL directly, drop detection and interim macro 2026-02-11 14:51:08 +01:00
PickyWarnings.cmake curl/curl.h: replace recursive macros with C++-friendly method to enforce 3 args 2026-03-21 13:21:06 +01:00
unix-cache.cmake build: check MSG_NOSIGNAL directly, drop detection and interim macro 2026-02-11 14:51:08 +01:00
Utilities.cmake cmake: fix LOCATION property access condition (debug) 2026-03-06 15:35:27 +01:00
win32-cache.cmake build: drop unused snprintf() feature check on Windows 2026-03-02 22:40:29 +01:00