add tests for LinkSelfContained options parsing

Author: lqd

compiler/rustc_session/src/lib.rs

@@ -33,6 +33,9 @@ pub mod output;
 
 pub use getopts;
 
+#[cfg(test)]
+mod tests;
+
 /// Requirements for a `StableHashingContext` to be used in this crate.
 /// This is a hack to allow using the `HashStable_Generic` derive macro
 /// instead of implementing everything in `rustc_middle`.

compiler/rustc_session/src/tests.rs

@@ -0,0 +1,71 @@
+use std::str::FromStr;
+
+use crate::config::{LinkSelfContained, LinkSelfContainedCrt, LinkSelfContainedLinker};
+
+/// When adding support for `-C link-self-contained=linker`, we want to ensure the existing
+/// values are still supported as-is: they are option values that can be used on stable.
+#[test]
+pub fn parse_stable_self_contained() {
+    // The existing default is when the argument is not used, the behavior depends on the
+    // target.
+    assert_eq!(
+        LinkSelfContained::default(),
+        LinkSelfContained { crt: LinkSelfContainedCrt::Auto, linker: LinkSelfContainedLinker::Off }
+    );
+
+    // Turning the flag `on` should currently only enable the default on stable.
+    assert_eq!(
+        LinkSelfContained::from_str("on"),
+        Ok(LinkSelfContained {
+            crt: LinkSelfContainedCrt::On,
+            linker: LinkSelfContainedLinker::Off
+        })
+    );
+
+    // Turning the flag `off` applies to both facets.
+    assert_eq!(
+        LinkSelfContained::from_str("off"),
+        Ok(LinkSelfContained {
+            crt: LinkSelfContainedCrt::Off,
+            linker: LinkSelfContainedLinker::Off
+        })
+    );
+
+    assert_eq!(
+        LinkSelfContained::from_str("crt"),
+        Ok(LinkSelfContained {
+            crt: LinkSelfContainedCrt::On,
+            linker: LinkSelfContainedLinker::Off
+        })
+    );
+}
+
+#[test]
+pub fn parse_self_contained_with_linker() {
+    // Turning the linker on doesn't change the CRT behavior
+    assert_eq!(
+        LinkSelfContained::from_str("linker"),
+        Ok(LinkSelfContained {
+            crt: LinkSelfContainedCrt::Auto,
+            linker: LinkSelfContainedLinker::On
+        })
+    );
+
+    assert_eq!(
+        LinkSelfContained::from_str("all"),
+        Ok(LinkSelfContained {
+            crt: LinkSelfContainedCrt::On,
+            linker: LinkSelfContainedLinker::On
+        })
+    );
+
+    // If `linker` is turned on by default someday, we need to be able to go back to the current
+    // default.
+    assert_eq!(
+        LinkSelfContained::from_str("auto"),
+        Ok(LinkSelfContained {
+            crt: LinkSelfContainedCrt::Auto,
+            linker: LinkSelfContainedLinker::Off
+        })
+    );
+}