Merge #123: cmake: Bump CMake minimum required version up to 3.22

a6a746e fixup! ci: Test CMake edge cases (Hennadii Stepanov)
d267c2c [FIXUP] cmake: Drop deprecated TestBigEndian module (Hennadii Stepanov)
b6cb4bb fixup! cmake: Check system symbols (Hennadii Stepanov)
4d67f35 fixup! cmake: Add `Maintenance` module (Hennadii Stepanov)
ae5bd32 fixup! cmake: Add cross-compiling support (Hennadii Stepanov)
4b0d7f5 fixup! build: Generate `share/toolchain.cmake` in depends (Hennadii Stepanov)
c7abb8f fixup! cmake: Add root `CMakeLists.txt` file (Hennadii Stepanov)

Pull request description:

  Considering the time when the new CMake-based build system will be available for users and bitcoin#29091, it seems reasonable to drop support for CMake versions older than 3.22.

  For CMake version availability, please refer to https://repology.org/project/cmake/versions.

  If an OS has no supported CMake in its system/default package manager, the user is still able to download it from https://cmake.org/download//

  Please refer to commit messages for detailed explanations of code changes.

ACKs for top commit:
  pablomartin4btc:
    tACK a6a746e
  vasild:
    ACK a6a746e

Tree-SHA512: ad2e2a31fc65f9459d38b5f226281820fb6e4bb044ed70413157fa339303c511d4ea70a3a21352cc6a200cba057e394c1ba92f8a8f7faeec2955707e95461d9d

Author: hebasto

.github/workflows/cmake.yml

@@ -170,17 +170,17 @@ jobs:
       - name: Generate build system. Expected to FAIL
         if: ${{ matrix.conf.expected == 'fail' }}
         run: |
-          ! cmake -B build -DCMAKE_TOOLCHAIN_FILE=depends/x86_64-pc-linux-gnu/share/toolchain.cmake ${{ matrix.conf.build_options }}
+          ! cmake -B build --toolchain depends/x86_64-pc-linux-gnu/share/toolchain.cmake ${{ matrix.conf.build_options }}
 
       - name: Generate build system. Expected to PASS
         if: ${{ matrix.conf.expected == 'pass' }}
         run: |
-          cmake -B build -DCMAKE_TOOLCHAIN_FILE=depends/x86_64-pc-linux-gnu/share/toolchain.cmake
+          cmake -B build --toolchain depends/x86_64-pc-linux-gnu/share/toolchain.cmake
 
 
-  ubuntu-focal-native:
-    name: 'Ubuntu 20.04, CMake 3.16, Boost ${{ matrix.conf.boost_version }}'
-    runs-on: ubuntu-20.04
+  ubuntu-jammy-native:
+    name: 'Ubuntu 22.04, CMake 3.22, Boost ${{ matrix.conf.boost_version }}'
+    runs-on: ubuntu-22.04
 
     strategy:
       fail-fast: false
@@ -204,7 +204,7 @@ jobs:
       - name: Install packages
         run: |
           sudo apt-get update
-          sudo apt-get install --no-install-recommends curl g++10 cmake ccache libevent-dev libsqlite3-dev libdb-dev libdb++-dev libminiupnpc-dev libnatpmp-dev libzmq3-dev systemtap-sdt-dev
+          sudo apt-get install --no-install-recommends curl cmake ccache libevent-dev libsqlite3-dev libdb-dev libdb++-dev libminiupnpc-dev libnatpmp-dev libzmq3-dev systemtap-sdt-dev
           echo "CCACHE_DIR=${{ runner.temp }}/ccache" >> "$GITHUB_ENV"
 
       - name: CMake version

CMakeLists.txt

@@ -1,21 +1,21 @@
-# Copyright (c) 2023 The Bitcoin Core developers
+# Copyright (c) 2023-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+# file COPYING or https://opensource.org/license/mit/.
 
 # IMPORTANT: Changes which affect binary results may not be quietly gated
 #            by CMake version.
 #
-# Ubuntu 20.04 LTS Focal Fossa, https://wiki.ubuntu.com/Releases, EOSS in April 2025:
-#  - CMake 3.16.3, https://packages.ubuntu.com/focal/cmake
+# Ubuntu 22.04 LTS Jammy Jellyfish, https://wiki.ubuntu.com/Releases, EOSS in June 2027:
+#  - CMake 3.22.1, https://packages.ubuntu.com/jammy/cmake
 #
-# Centos Stream 8, EOL in May 2024:
-#  - CMake 3.20.2, http://mirror.centos.org/centos/8-stream/AppStream/x86_64/os/Packages/
+# Centos Stream 9, EOL in May 2027:
+#  - CMake 3.26.5, https://mirror.stream.centos.org/9-stream/AppStream/x86_64/os/Packages/
 #
 # All policies known to the running version of CMake and introduced
-# in the 3.28 version or earlier will be set to use NEW behavior.
+# in the 3.29 version or earlier will be set to use NEW behavior.
 # All policies introduced in later versions will be unset.
 # See: https://cmake.org/cmake/help/latest/manual/cmake-policies.7.html
-cmake_minimum_required(VERSION 3.16...3.28)
+cmake_minimum_required(VERSION 3.22...3.29)
 
 set(PACKAGE_NAME "Bitcoin Core")
 set(CLIENT_VERSION_MAJOR 27)

cmake/bitcoin-config.h.in

@@ -130,10 +130,6 @@
 /* Define to 1 if strerror_r returns char *. */
 #cmakedefine STRERROR_R_CHAR_P 1
 
-/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
-   significant byte first (like Motorola and SPARC, unlike Intel). */
-#cmakedefine WORDS_BIGENDIAN 1
-
 /* Define to 1 to enable wallet functions. */
 #cmakedefine ENABLE_WALLET 1
 

cmake/crc32c.cmake

@@ -90,7 +90,7 @@ target_compile_definitions(crc32c
     HAVE_STRONG_GETAUXVAL=$<BOOL:${HAVE_STRONG_GETAUXVAL}>
     HAVE_SSE42=$<BOOL:${HAVE_SSE42}>
     HAVE_ARM64_CRC32C=$<BOOL:${HAVE_ARM64_CRC32C}>
-    BYTE_ORDER_BIG_ENDIAN=${WORDS_BIGENDIAN}
+    BYTE_ORDER_BIG_ENDIAN=$<STREQUAL:${CMAKE_CXX_BYTE_ORDER},BIG_ENDIAN>
 )
 
 target_include_directories(crc32c

cmake/introspection.cmake

@@ -5,9 +5,6 @@
 include(CheckCXXSourceCompiles)
 include(CheckCXXSymbolExists)
 include(CheckIncludeFileCXX)
-include(TestBigEndian)
-
-test_big_endian(WORDS_BIGENDIAN)
 
 # The following HAVE_{HEADER}_H variables go to the bitcoin-config.h header.
 check_include_file_cxx(sys/prctl.h HAVE_SYS_PRCTL_H)

cmake/leveldb.cmake

@@ -60,7 +60,7 @@ target_compile_definitions(leveldb
     HAVE_FULLFSYNC=$<BOOL:${HAVE_FULLFSYNC}>
     HAVE_O_CLOEXEC=$<BOOL:${HAVE_O_CLOEXEC}>
     FALLTHROUGH_INTENDED=[[fallthrough]]
-    LEVELDB_IS_BIG_ENDIAN=${WORDS_BIGENDIAN}
+    LEVELDB_IS_BIG_ENDIAN=$<STREQUAL:${CMAKE_CXX_BYTE_ORDER},BIG_ENDIAN>
     $<$<NOT:$<BOOL:${WIN32}>>:LEVELDB_PLATFORM_POSIX>
     $<$<BOOL:${WIN32}>:LEVELDB_PLATFORM_WINDOWS>
     $<$<BOOL:${WIN32}>:_UNICODE;UNICODE>

cmake/module/CrossPkgConfig.cmake

@@ -1,35 +1,9 @@
-# Copyright (c) 2023 The Bitcoin Core developers
+# Copyright (c) 2023-present The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
-# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+# file COPYING or https://opensource.org/license/mit/.
 
 find_package(PkgConfig REQUIRED)
 
-function(remove_isystem_from_include_directories_internal target)
-  #[=[
-  A workaround for https://gitlab.kitware.com/cmake/cmake/-/issues/20652.
-
-  When the pkg-config provides CFLAGS with -isystem options, for instance:
-
-    $ pkg-config --cflags-only-I libzmq
-    -isystem /usr/include/mit-krb5 -I/usr/include/pgm-5.3 -I/usr/include/libxml2
-
-  an old CMake fails to parse them properly and the INTERFACE_INCLUDE_DIRECTORIES
-  property contains "-isystem" as a separated element:
-
-    -isystem;/usr/include/mit-krb5;/usr/include/pgm-5.3;/usr/include/libxml2
-
-  which ends with an error "Imported target includes non-existent path".
-
-  Fixing by removing the "-isystem" element from the INTERFACE_INCLUDE_DIRECTORIES.
-  ]=]
-
-  get_target_property(include_directories ${target} INTERFACE_INCLUDE_DIRECTORIES)
-  if(include_directories)
-    list(REMOVE_ITEM include_directories -isystem)
-    set_target_properties(${target} PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${include_directories}")
-  endif()
-endfunction()
-
 macro(cross_pkg_check_modules prefix)
   if(CMAKE_CROSSCOMPILING)
     set(pkg_config_path_saved "$ENV{PKG_CONFIG_PATH}")
@@ -39,11 +13,9 @@ macro(cross_pkg_check_modules prefix)
     pkg_check_modules(${prefix} ${ARGN})
     set(ENV{PKG_CONFIG_PATH} ${pkg_config_path_saved})
     set(ENV{PKG_CONFIG_LIBDIR} ${pkg_config_libdir_saved})
+    unset(pkg_config_path_saved)
+    unset(pkg_config_libdir_saved)
   else()
     pkg_check_modules(${prefix} ${ARGN})
   endif()
-
-  if(CMAKE_VERSION VERSION_LESS 3.17.3 AND TARGET PkgConfig::${prefix})
-    remove_isystem_from_include_directories_internal(PkgConfig::${prefix})
-  endif()
 endmacro()

cmake/module/Maintenance.cmake

@@ -8,20 +8,13 @@ function(setup_split_debug_script)
   if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux")
     set(OBJCOPY ${CMAKE_OBJCOPY})
     set(STRIP ${CMAKE_STRIP})
-    if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.20)
-      configure_file(
-        contrib/devtools/split-debug.sh.in split-debug.sh
-        FILE_PERMISSIONS OWNER_READ OWNER_EXECUTE
-                         GROUP_READ GROUP_EXECUTE
-                         WORLD_READ
-        @ONLY
-      )
-    else()
-      configure_file(
-        contrib/devtools/split-debug.sh.in split-debug.sh
-        @ONLY
-      )
-    endif()
+    configure_file(
+      contrib/devtools/split-debug.sh.in split-debug.sh
+      FILE_PERMISSIONS OWNER_READ OWNER_EXECUTE
+                       GROUP_READ GROUP_EXECUTE
+                       WORLD_READ
+      @ONLY
+    )
   endif()
 endfunction()
 

cmake/module/TestAppendRequiredLibraries.cmake

@@ -9,7 +9,7 @@ include_guard(GLOBAL)
 # See: https://github.com/bitcoin/bitcoin/pull/21486
 function(test_append_socket_library target)
   if (NOT TARGET ${target})
-    message(FATAL_ERROR "test_append_socket_library() called with non-existent target \"${target}\".")
+    message(FATAL_ERROR "${CMAKE_CURRENT_FUNCTION}() called with non-existent target \"${target}\".")
   endif()
 
   set(check_socket_source "
@@ -45,7 +45,7 @@ endfunction()
 # Sourced from http://bugs.debian.org/797228
 function(test_append_atomic_library target)
   if (NOT TARGET ${target})
-    message(FATAL_ERROR "test_append_atomic_library() called with non-existent target \"${target}\".")
+    message(FATAL_ERROR "${CMAKE_CURRENT_FUNCTION}() called with non-existent target \"${target}\".")
   endif()
 
   set(check_atomic_source "

depends/toolchain.cmake.in

@@ -35,41 +35,14 @@ endfunction()
 if(NOT CMAKE_C_COMPILER)
   set(DEPENDS_C_COMPILER_WITH_LAUNCHER @CC@)
   split_compiler_launcher(DEPENDS_C_COMPILER_WITH_LAUNCHER CMAKE_C_COMPILER_LAUNCHER CMAKE_C_COMPILER)
-  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.21)
-    set(CMAKE_C_LINKER_LAUNCHER ${CMAKE_C_COMPILER_LAUNCHER})
-  endif()
-  if(CMAKE_VERSION VERSION_LESS 3.19)
-    # Being provided with CC="compiler -arg1 -arg2", the old CMake cannot
-    # store the compiler arguments in the CMAKE_C_COMPILER variable.
-    # Therefore, we have to store them separately.
-    set(mandatory_c_compiler_flags ${CMAKE_C_COMPILER})
-    list(POP_FRONT mandatory_c_compiler_flags CMAKE_C_COMPILER)
-    list(JOIN mandatory_c_compiler_flags " " mandatory_c_compiler_flags)
-    string(PREPEND CMAKE_C_FLAGS_INIT "${mandatory_c_compiler_flags} ")
-    unset(mandatory_c_compiler_flags)
-  endif()
+  set(CMAKE_C_LINKER_LAUNCHER ${CMAKE_C_COMPILER_LAUNCHER})
   set(DEPENDS_C_COMPILER_FLAGS @CFLAGS@)
 endif()
 
 if(NOT CMAKE_CXX_COMPILER)
   set(DEPENDS_CXX_COMPILER_WITH_LAUNCHER @CXX@)
   split_compiler_launcher(DEPENDS_CXX_COMPILER_WITH_LAUNCHER CMAKE_CXX_COMPILER_LAUNCHER CMAKE_CXX_COMPILER)
-  if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.21)
-    set(CMAKE_CXX_LINKER_LAUNCHER ${CMAKE_CXX_COMPILER_LAUNCHER})
-  endif()
-  if(CMAKE_VERSION VERSION_LESS 3.19)
-    # Being provided with CXX="compiler -arg1 -arg2", the old CMake cannot
-    # store the compiler arguments in the CMAKE_CXX_COMPILER variable.
-    # Therefore, we have to store them separately.
-    set(mandatory_cxx_compiler_flags ${CMAKE_CXX_COMPILER})
-    list(POP_FRONT mandatory_cxx_compiler_flags CMAKE_CXX_COMPILER)
-    list(JOIN mandatory_cxx_compiler_flags " " mandatory_cxx_compiler_flags)
-    string(PREPEND CMAKE_CXX_FLAGS_INIT "${mandatory_cxx_compiler_flags} ")
-    string(PREPEND CMAKE_OBJCXX_FLAGS_INIT "${mandatory_cxx_compiler_flags} ")
-    string(PREPEND CMAKE_EXE_LINKER_FLAGS_INIT "${mandatory_cxx_compiler_flags} ")
-    string(PREPEND CMAKE_SHARED_LINKER_FLAGS_INIT "${mandatory_cxx_compiler_flags} ")
-    unset(mandatory_cxx_compiler_flags)
-  endif()
+  set(CMAKE_CXX_LINKER_LAUNCHER ${CMAKE_CXX_COMPILER_LAUNCHER})
   set(DEPENDS_CXX_COMPILER_FLAGS @CXXFLAGS@)
 
   set(CMAKE_OBJCXX_COMPILER ${CMAKE_CXX_COMPILER})