Merge bitcoin#29835: depends: build libevent with CMake

f59e905 depends: switch libevent to CMake (Cory Fields)

Pull request description:

  Switches libevent in depends to be built with CMake.

ACKs for top commit:
  TheCharlatan:
    ACK f59e905
  willcl-ark:
    ACK f59e905

Tree-SHA512: 875bf9bc57653c78775a1f8192a2c964fea8f4490d733ff796d9efb00e786f0ca9a7c1a3fd610cda032273c4f2ae06394585b03567d5f241ab073c83a47cf927

depends/packages/libevent.mk

@@ -3,23 +3,25 @@ $(package)_version=2.1.12-stable
 $(package)_download_path=https://github.com/libevent/libevent/releases/download/release-$($(package)_version)/
 $(package)_file_name=$(package)-$($(package)_version).tar.gz
 $(package)_sha256_hash=92e6de1be9ec176428fd2367677e61ceffc2ee1cb119035037a27d346b0403bb
+$(package)_patches=cmake_fixups.patch
+$(package)_build_subdir=build
 
 # When building for Windows, we set _WIN32_WINNT to target the same Windows
 # version as we do in configure. Due to quirks in libevents build system, this
 # is also required to enable support for ipv6. See #19375.
 define $(package)_set_vars
-  $(package)_config_opts=--disable-shared --disable-openssl --disable-libevent-regress --disable-samples
-  $(package)_config_opts += --disable-dependency-tracking --enable-option-checking
-  $(package)_config_opts_release=--disable-debug-mode
+  $(package)_config_opts=-DEVENT__DISABLE_BENCHMARK=ON -DEVENT__DISABLE_OPENSSL=ON
+  $(package)_config_opts+=-DEVENT__DISABLE_SAMPLES=ON -DEVENT__DISABLE_REGRESS=ON
+  $(package)_config_opts+=-DEVENT__DISABLE_TESTS=ON -DEVENT__LIBRARY_TYPE=STATIC
   $(package)_cppflags_mingw32=-D_WIN32_WINNT=0x0601
 endef
 
 define $(package)_preprocess_cmds
-  cp -f $(BASEDIR)/config.guess $(BASEDIR)/config.sub build-aux
+  patch -p1 < $($(package)_patch_dir)/cmake_fixups.patch
 endef
 
 define $(package)_config_cmds
-  $($(package)_autoconf)
+  $($(package)_cmake) -S .. -B .
 endef
 
 define $(package)_build_cmds
@@ -31,7 +33,7 @@ define $(package)_stage_cmds
 endef
 
 define $(package)_postprocess_cmds
-  rm lib/*.la && \
+  rm bin/event_rpcgen.py && \
   rm include/ev*.h && \
   rm include/event2/*_compat.h
 endef

depends/patches/libevent/cmake_fixups.patch

@@ -0,0 +1,35 @@
+cmake: set minimum version to 3.5
+
+Fix generated pkg-config files, see
+https://github.com/libevent/libevent/pull/1165.
+
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -19,7 +19,7 @@
+ #       start libevent.sln
+ #
+
+-cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
++cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+
+ if (POLICY CMP0054)
+     cmake_policy(SET CMP0054 NEW)
+diff --git a/cmake/AddEventLibrary.cmake b/cmake/AddEventLibrary.cmake
+index 04f5837e..d8ea42c4 100644
+--- a/cmake/AddEventLibrary.cmake
++++ b/cmake/AddEventLibrary.cmake
+@@ -20,12 +20,12 @@ macro(generate_pkgconfig LIB_NAME)
+
+     set(LIBS         "")
+     foreach (LIB ${LIB_PLATFORM})
+-        set(LIBS "${LIBS} -L${LIB}")
++        set(LIBS "${LIBS} -l${LIB}")
+     endforeach()
+
+     set(OPENSSL_LIBS "")
+     foreach(LIB ${OPENSSL_LIBRARIES})
+-        set(OPENSSL_LIBS "${OPENSSL_LIBS} -L${LIB}")
++        set(OPENSSL_LIBS "${OPENSSL_LIBS} -l${LIB}")
+     endforeach()
+
+     configure_file("lib${LIB_NAME}.pc.in" "lib${LIB_NAME}.pc" @ONLY)