Merge bitcoin/bitcoin#29878: depends: build expat with CMake

a517029 depends: switch to building expat with CMake (fanquake)

Pull request description:

  Switch to building Expat with CMake, instead of Autotools.

ACKs for top commit:
  hebasto:
    re-ACK a517029.

Tree-SHA512: ca040545dd83fb81a8b209aa24cae6e22eaeff04f44bdabc4454adf6ea63d34f4ae27bd5980c65db2d2542e23eb2712102719023c262ab63a933c90b5999c11e

Author: fanquake

depends/packages/expat.mk

@@ -3,19 +3,25 @@ $(package)_version=2.4.8
 $(package)_download_path=https://github.com/libexpat/libexpat/releases/download/R_$(subst .,_,$($(package)_version))/
 $(package)_file_name=$(package)-$($(package)_version).tar.xz
 $(package)_sha256_hash=f79b8f904b749e3e0d20afeadecf8249c55b2e32d4ebb089ae378df479dcaf25
+$(package)_build_subdir=build
+$(package)_patches += cmake_minimum.patch
 
 # -D_DEFAULT_SOURCE defines __USE_MISC, which exposes additional
 # definitions in endian.h, which are required for a working
 # endianness check in configure when building with -flto.
 define $(package)_set_vars
-  $(package)_config_opts=--disable-shared --without-docbook --without-tests --without-examples
-  $(package)_config_opts += --disable-dependency-tracking --enable-option-checking
-  $(package)_config_opts += --without-xmlwf
+  $(package)_config_opts := -DCMAKE_BUILD_TYPE=None -DEXPAT_BUILD_TOOLS=OFF
+  $(package)_config_opts += -DEXPAT_BUILD_EXAMPLES=OFF -DEXPAT_BUILD_TESTS=OFF
+  $(package)_config_opts += -DBUILD_SHARED_LIBS=OFF
   $(package)_cppflags += -D_DEFAULT_SOURCE
 endef
 
+define $(package)_preprocess_cmds
+  patch -p1 < $($(package)_patch_dir)/cmake_minimum.patch
+endef
+
 define $(package)_config_cmds
-  $($(package)_autoconf)
+  $($(package)_cmake) -S .. -B .
 endef
 
 define $(package)_build_cmds
@@ -27,5 +33,5 @@ define $(package)_stage_cmds
 endef
 
 define $(package)_postprocess_cmds
-  rm -rf share lib/cmake lib/*.la
+  rm -rf share lib/cmake
 endef

depends/patches/expat/cmake_minimum.patch

@@ -0,0 +1,13 @@
+build: set minimum required CMake to 3.16
+
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -33,7 +33,7 @@
+ # Unlike most of Expat,
+ # this file is copyrighted under the BSD-license for buildsystem files of KDE.
+ 
+-cmake_minimum_required(VERSION 3.1.3)
++cmake_minimum_required(VERSION 3.16)
+ 
+ # This allows controlling documented build time switches
+ # when Expat is pulled in using the add_subdirectory function, e.g.