merge bitcoin#31500: Fix compiling libevent package on NetBSD

Author: kwvg

depends/packages/libevent.mk

@@ -4,7 +4,8 @@ $(package)_download_path=https://github.com/libevent/libevent/releases/download/
 $(package)_file_name=$(package)-$($(package)_version).tar.gz
 $(package)_sha256_hash=92e6de1be9ec176428fd2367677e61ceffc2ee1cb119035037a27d346b0403bb
 $(package)_patches=cmake_fixups.patch
-$(package)_patches+=fix_mingw_link.patch
+$(package)_patches += fix_mingw_link.patch
+$(package)_patches += netbsd_fixup.patch
 $(package)_build_subdir=build
 
 # When building for Windows, we set _WIN32_WINNT to target the same Windows
@@ -25,7 +26,8 @@ endef
 
 define $(package)_preprocess_cmds
   patch -p1 < $($(package)_patch_dir)/cmake_fixups.patch && \
-  patch -p1 < $($(package)_patch_dir)/fix_mingw_link.patch
+  patch -p1 < $($(package)_patch_dir)/fix_mingw_link.patch && \
+  patch -p1 < $($(package)_patch_dir)/netbsd_fixup.patch
 endef
 
 define $(package)_config_cmds

depends/patches/libevent/netbsd_fixup.patch

@@ -0,0 +1,23 @@
+Improve portability on NetBSD
+
+According to GCC documentation, "the various `-std` options disable
+certain keywords".
+This change adheres to GCC's recommendation by replacing the `typeof`
+keyword with its alternative, `__typeof__`.
+
+See https://github.com/libevent/libevent/commit/1759485e9a59147a47a674f5132fcfe764e7748c.
+
+
+--- a/kqueue.c
++++ b/kqueue.c
+@@ -52,8 +52,8 @@
+  * intptr_t, whereas others define it as void*.  There doesn't seem to be an
+  * easy way to tell them apart via autoconf, so we need to use OS macros. */
+ #if defined(__NetBSD__)
+-#define PTR_TO_UDATA(x) ((typeof(((struct kevent *)0)->udata))(x))
+-#define INT_TO_UDATA(x) ((typeof(((struct kevent *)0)->udata))(intptr_t)(x))
++#define PTR_TO_UDATA(x) ((__typeof__(((struct kevent *)0)->udata))(x))
++#define INT_TO_UDATA(x) ((__typeof__(((struct kevent *)0)->udata))(intptr_t)(x))
+ #elif defined(EVENT__HAVE_INTTYPES_H) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__darwin__) && !defined(__APPLE__) && !defined(__CloudABI__)
+ #define PTR_TO_UDATA(x)	((intptr_t)(x))
+ #define INT_TO_UDATA(x) ((intptr_t)(x))