Find brew openssl in correct place on Apple Silicon/aarch64

Brew recommends to keep side-by-side installations for the time being,
placing aarch64 builds into /opt/homebrew. (My feeling says using an alternative root for homebrew is there to stay,
but that may be wrong.)

That said, now `brew` in PATH may either be an aarch64 version from
`/opt/homebrew`, or it may be an intel one. And the only way I know to
differentiate them is by their path of origin and thus by convention.

Since 'pkg-config' doesn't work for me as it doesn't actually know
openssl despite it being installed as dependency and since `brew`
may refer to either architecture, hard-coding well-known paths
on MacOS seems to be the only option.

1 files changed, 42 insertions, 23 deletions

diff --git a/openssl-sys/build/find_normal.rs b/openssl-sys/build/find_normal.rs
index 3a09aea3..4e492e7d 100644
--- a/openssl-sys/build/find_normal.rs
+++ b/openssl-sys/build/find_normal.rs
@@ -21,34 +21,53 @@ pub fn get_openssl(target: &str) -> (PathBuf, PathBuf) {
     }
 }
 
-fn find_openssl_dir(target: &str) -> OsString {
-    let host = env::var("HOST").unwrap();
-
-    if host == target && target.contains("apple-darwin") {
-        // Check up default Homebrew installation location first
-        // for quick resolution if possible.
-        let homebrew = Path::new("/usr/local/opt/openssl@1.1");
+fn resolve_with_wellknown_homebrew_location(dir: &str) -> Option<PathBuf> {
+    // Check up default aarch 64 Homebrew installation location first
+    // for quick resolution if possible.
+    //  `pkg-config` on brew doesn't necessarily contain settings for openssl apparently.
+    let mut version_dir = dir.to_owned();
+    version_dir.push_str("@1.1");
+    let homebrew = Path::new(&version_dir);
+    if homebrew.exists() {
+        return Some(homebrew.to_path_buf());
+    }
+    let homebrew = Path::new(dir);
+    if homebrew.exists() {
+        return Some(homebrew.to_path_buf());
+    }
+    // Calling `brew --prefix <package>` command usually slow and
+    // takes seconds, and will be used only as a last resort.
+    let output = execute_command_and_get_output("brew", &["--prefix", "openssl@1.1"]);
+    if let Some(ref output) = output {
+        let homebrew = Path::new(&output);
         if homebrew.exists() {
-            return homebrew.to_path_buf().into();
+            return Some(homebrew.to_path_buf());
         }
-        let homebrew = Path::new("/usr/local/opt/openssl");
+    }
+
+    let output = execute_command_and_get_output("brew", &["--prefix", "openssl"]);
+    if let Some(ref output) = output {
+        let homebrew = Path::new(&output);
         if homebrew.exists() {
-            return homebrew.to_path_buf().into();
+            return Some(homebrew.to_path_buf());
         }
-        // Calling `brew --prefix <package>` command usually slow and
-        // takes seconds, and will be used only as a last resort.
-        let output = execute_command_and_get_output("brew", &["--prefix", "openssl@1.1"]);
-        if let Some(ref output) = output {
-            let homebrew = Path::new(&output);
-            if homebrew.exists() {
-                return homebrew.to_path_buf().into();
+    }
+
+    None
+}
+
+fn find_openssl_dir(target: &str) -> OsString {
+    let host = env::var("HOST").unwrap();
+
+    if host == target {
+        if target == "aarch64-apple-darwin" {
+            if let Some(dir) = resolve_with_wellknown_homebrew_location("/opt/homebrew/opt/openssl")
+            {
+                return dir.into();
             }
-        }
-        let output = execute_command_and_get_output("brew", &["--prefix", "openssl"]);
-        if let Some(ref output) = output {
-            let homebrew = Path::new(&output);
-            if homebrew.exists() {
-                return homebrew.to_path_buf().into();
+        } else if target.contains("apple-darwin") {
+            if let Some(dir) = resolve_with_wellknown_homebrew_location("/usr/local/opt/openssl") {
+                return dir.into();
             }
         }
     }