From 26bc1785d3d69847d08527e97b273ede31c2a5ce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9o=20Gaspard?= <leo@gaspard.io>
Date: Tue, 12 Jan 2021 00:48:28 +0100
Subject: [PATCH] wasi-common: add preopened_handle, to be able to open any
 handle

---
 crates/wasi-common/src/ctx.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/crates/wasi-common/src/ctx.rs b/crates/wasi-common/src/ctx.rs
index e73fbb4ea630..103aee73a854 100644
--- a/crates/wasi-common/src/ctx.rs
+++ b/crates/wasi-common/src/ctx.rs
@@ -268,6 +268,22 @@ impl WasiCtxBuilder {
         self
     }
 
+    /// Add a preopened handle.
+    ///
+    /// This is the most generic function for adding a directory, but also the less easy to use.
+    pub fn preopened_handle<P: AsRef<Path>, T: 'static + Handle>(
+        &mut self,
+        dir: T,
+        guest_path: P,
+    ) -> &mut Self {
+        let preopen = PendingPreopen::new(move || Ok(Box::new(dir)));
+        self.preopens
+            .as_mut()
+            .unwrap()
+            .push((guest_path.as_ref().to_owned(), preopen));
+        self
+    }
+
     /// Build a `WasiCtx`, consuming this `WasiCtxBuilder`.
     ///
     /// If any of the arguments or environment variables in this builder cannot be converted into