SIL Verifier: avoid crashing for a missing borrowed-from - instead report an error

eeckstein · eeckstein · commit df62235fe6bb · 2025-01-09T19:56:25.000+01:00
diff --git a/SwiftCompilerSources/Sources/Optimizer/Utilities/Verifier.swift b/SwiftCompilerSources/Sources/Optimizer/Utilities/Verifier.swift
@@ -164,7 +164,11 @@ private struct MutatingUsesWalker : AddressDefUseWalker {
 
       for use in startInst.uses {
         if let phi = Phi(using: use) {
-          linearLiveranges.pushIfNotVisited(phi.borrowedFrom!)
+          if let bf = phi.borrowedFrom {
+            linearLiveranges.pushIfNotVisited(bf)
+          } else {
+            require(false, "missing borrowed-from for \(phi.value)")
+          }
         }
       }
     }

Original file line number	Diff line number	Diff line change
`@@ -164,7 +164,11 @@ private struct MutatingUsesWalker : AddressDefUseWalker {`
`164`	`164`
`165`	`165`	`for use in startInst.uses {`
`166`	`166`	`if let phi = Phi(using: use) {`
`167`		`- linearLiveranges.pushIfNotVisited(phi.borrowedFrom!)`
	`167`	`+ if let bf = phi.borrowedFrom {`
	`168`	`+ linearLiveranges.pushIfNotVisited(bf)`
	`169`	`+ } else {`
	`170`	`+ require(false, "missing borrowed-from for \(phi.value)")`
	`171`	`+ }`
`168`	`172`	`}`
`169`	`173`	`}`
`170`	`174`	`}`