From f5f608b7b2339499197819503c892e46939f1fea Mon Sep 17 00:00:00 2001
From: Shawn Presser <shawnpresser@gmail.com>
Date: Tue, 31 Oct 2023 19:54:29 -0700
Subject: [PATCH] build: add checks for openssl dir via brew on macOS

---
 .gitignore               |  1 +
 configure.ac             |  3 +++
 m4/check_darwin_paths.m4 | 23 +++++++++++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 m4/check_darwin_paths.m4

diff --git a/.gitignore b/.gitignore
index 52556ec5..d1cb67fa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@
 /configure~
 # m4/ directory: only keep certain files
 /m4/*
+!/m4/check_darwin_paths.m4
 !/m4/check_disable_compiler_warnings.m4
 !/m4/check_libcperciva_posix.m4
 !/m4/check_memlimit_support.m4
diff --git a/configure.ac b/configure.ac
index e1f56d23..d9a6c57c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -27,6 +27,9 @@ CHECK_POSIX_SH
 # Check if we need -std=c99 in LDFLAGS (for gcc on Solaris).
 CHECK_SOLARIS_C99
 
+# Check if we need to add extra paths to CPPFLAGS and LDFLAGS for macOS.
+CHECK_DARWIN_PATHS
+
 # Checks for AES support in OpenSSL.
 AC_SEARCH_LIBS([AES_encrypt], [crypto],,
     AC_MSG_ERROR([function AES_ENCRYPT not found]))
diff --git a/m4/check_darwin_paths.m4 b/m4/check_darwin_paths.m4
new file mode 100644
index 00000000..f7b025c4
--- /dev/null
+++ b/m4/check_darwin_paths.m4
@@ -0,0 +1,23 @@
+# CHECK_DARWIN_PATHS
+# -------------------
+AC_DEFUN([CHECK_DARWIN_PATHS],
+[AC_REQUIRE([AC_CANONICAL_TARGET])
+
+case $target_os in
+*darwin*)
+	# Get the homebrew directory, which varies based on arch.
+	case "$(uname -m)" in
+	arm64)
+		homebrew_dir=/opt/homebrew
+		;;
+	*)
+		homebrew_dir=/usr/local
+		;;
+	esac
+
+	# Use the homebrew directory to specify the paths to openssl.
+	CPPFLAGS="${CPPFLAGS} -I${homebrew_dir}/opt/openssl/include"
+	LDFLAGS="${LDFLAGS} -L${homebrew_dir}/opt/openssl/lib"
+	;;
+esac
+])# CHECK_DARWIN_PATHS