handle empty string rustc wrapper envs (#7)

taiki-e · Feb 23, 2023 · 1d7d634 · 1d7d634
1 parent 8ad4c8d
commit 1d7d634
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Showing 2 changed files with 44 additions and 12 deletions.
diff --git a/src/env.rs b/src/env.rs
@@ -72,20 +72,40 @@ impl ApplyEnv for BuildConfig {
         // 1. RUSTC_WRAPPER
         // 2. build.rustc-wrapper (CARGO_BUILD_RUSTC_WRAPPER)
         // https://doc.rust-lang.org/nightly/cargo/reference/config.html#buildrustc-wrapper
+        // Setting this to an empty string instructs cargo to not use a wrapper.
+        // https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-reads
         if let Some(rustc_wrapper) = cx.env("RUSTC_WRAPPER")? {
-            self.rustc_wrapper = Some(rustc_wrapper);
+            if rustc_wrapper.val.is_empty() {
+                self.rustc_wrapper = None;
+            } else {
+                self.rustc_wrapper = Some(rustc_wrapper);
+            }
         } else if let Some(rustc_wrapper) = cx.env("CARGO_BUILD_RUSTC_WRAPPER")? {
-            self.rustc_wrapper = Some(rustc_wrapper);
+            if rustc_wrapper.val.is_empty() {
+                self.rustc_wrapper = None;
+            } else {
+                self.rustc_wrapper = Some(rustc_wrapper);
+            }
         }
         // 1. RUSTC_WORKSPACE_WRAPPER
         // 2. build.rustc-workspace-wrapper (CARGO_BUILD_RUSTC_WORKSPACE_WRAPPER)
         // https://doc.rust-lang.org/nightly/cargo/reference/config.html#buildrustc-workspace-wrapper
+        // Setting this to an empty string instructs cargo to not use a wrapper.
+        // https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-reads
         if let Some(rustc_workspace_wrapper) = cx.env("RUSTC_WORKSPACE_WRAPPER")? {
-            self.rustc_workspace_wrapper = Some(rustc_workspace_wrapper);
+            if rustc_workspace_wrapper.val.is_empty() {
+                self.rustc_workspace_wrapper = None;
+            } else {
+                self.rustc_workspace_wrapper = Some(rustc_workspace_wrapper);
+            }
         } else if let Some(rustc_workspace_wrapper) =
             cx.env("CARGO_BUILD_RUSTC_WORKSPACE_WRAPPER")?
         {
-            self.rustc_workspace_wrapper = Some(rustc_workspace_wrapper);
+            if rustc_workspace_wrapper.val.is_empty() {
+                self.rustc_workspace_wrapper = None;
+            } else {
+                self.rustc_workspace_wrapper = Some(rustc_workspace_wrapper);
+            }
         }
         // 1. RUSTDOC
         // 2. build.rustdoc (CARGO_BUILD_RUSTDOC)
@@ -246,3 +266,22 @@ impl ApplyEnv for TermProgress {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::ApplyEnv;
+    use crate::{value::Value, ResolveOptions};
+
+    #[test]
+    fn empty_string_wrapper_envs() {
+        let env_list = [("RUSTC_WRAPPER", ""), ("RUSTC_WORKSPACE_WRAPPER", "")];
+        let mut config = crate::de::BuildConfig::default();
+        let cx = &ResolveOptions::default().env(env_list).into_context();
+        config.rustc_wrapper = Some(Value { val: "rustc_wrapper".to_string(), definition: None });
+        config.rustc_workspace_wrapper =
+            Some(Value { val: "rustc_workspace_wrapper".to_string(), definition: None });
+        config.apply_env(cx).unwrap();
+        assert!(config.rustc_wrapper.is_none());
+        assert!(config.rustc_workspace_wrapper.is_none());
+    }
+}
diff --git a/src/resolve.rs b/src/resolve.rs
@@ -676,14 +676,7 @@ mod tests {
             ("CARGO_TERM_PROGRESS_WIDTH", "100"),
         ];
         let mut config = crate::de::Config::default();
-        let cx = &ResolveOptions::default()
-            .env(env_list)
-            .cargo_home(None)
-            .rustc(PathAndArgs::new("rustc"))
-            .into_context();
-        for (k, v) in env_list {
-            assert_eq!(cx.env[k], v, "key={k},value={v}");
-        }
+        let cx = &ResolveOptions::default().env(env_list).into_context();
         config.apply_env(cx).unwrap();
     }