From 8f7704d0321a71c1691837a6bd3b4e05f84d3031 Mon Sep 17 00:00:00 2001
From: fanquake <fanquake@gmail.com>
Date: Mon, 14 Jun 2021 13:35:05 +0800
Subject: [PATCH] build: improve detection of eBPF support

Just checking for the `sys/sdt.h` header isn't enough, as systems like
macOS have the header, but it doesn't actually have the dtrace probes,
which leads to compile failures.
---
 configure.ac | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index aaa932b093..77cb5dd326 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1357,13 +1357,15 @@ if test x$enable_wallet != xno; then
 fi
 
 if test x$use_ebpf != xno; then
-  AC_CHECK_HEADER([sys/sdt.h], [have_sdt=yes], [have_sdt=no])
-else
-  have_sdt=no
-fi
-
-if test x$have_sdt = xyes; then
-  AC_DEFINE([ENABLE_TRACING], [1], [Define to 1 to enable eBPF user static defined tracepoints])
+  AC_MSG_CHECKING([whether eBPF tracepoints are supported])
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM(
+      [#include <sys/sdt.h>],
+      [DTRACE_PROBE("context", "event");]
+    )],
+    [AC_MSG_RESULT(yes); have_sdt=yes; AC_DEFINE([ENABLE_TRACING], [1], [Define to 1 to enable eBPF user static defined tracepoints])],
+    [AC_MSG_RESULT(no); have_sdt=no;]
+  )
 fi
 
 dnl Check for libminiupnpc (optional)