incr.comp.: Improve error message for unknown fingerprint.

michaelwoerister · michaelwoerister · commit 6a3659427e9c · 2017-11-07T08:54:38.000+01:00
diff --git a/src/librustc/dep_graph/graph.rs b/src/librustc/dep_graph/graph.rs
@@ -328,7 +328,12 @@ impl DepGraph {
     }
 
     pub fn fingerprint_of(&self, dep_node: &DepNode) -> Fingerprint {
-        self.fingerprints.borrow()[dep_node]
+        match self.fingerprints.borrow().get(dep_node) {
+            Some(&fingerprint) => fingerprint,
+            None => {
+                bug!("Could not find current fingerprint for {:?}", dep_node)
+            }
+        }
     }
 
     pub fn prev_fingerprint_of(&self, dep_node: &DepNode) -> Option<Fingerprint> {

Original file line number	Diff line number	Diff line change
`@@ -328,7 +328,12 @@ impl DepGraph {`
`328`	`328`	`}`
`329`	`329`
`330`	`330`	`pub fn fingerprint_of(&self, dep_node: &DepNode) -> Fingerprint {`
`331`		`- self.fingerprints.borrow()[dep_node]`
	`331`	`+ match self.fingerprints.borrow().get(dep_node) {`
	`332`	`+ Some(&fingerprint) => fingerprint,`
	`333`	`+ None => {`
	`334`	`+ bug!("Could not find current fingerprint for {:?}", dep_node)`
	`335`	`+ }`
	`336`	`+ }`
`332`	`337`	`}`
`333`	`338`
`334`	`339`	`pub fn prev_fingerprint_of(&self, dep_node: &DepNode) -> Option<Fingerprint> {`