Merge pull request swiftlang#30595 from slavapestov/rdar60081992

slavapestov · web-flow · commit d0fb9c65c371 · 2020-03-24T01:09:54.000-04:00
Sema: Fix interface type vs archetype mixup with generic typealiases
diff --git a/lib/Sema/TypeCheckType.cpp b/lib/Sema/TypeCheckType.cpp
@@ -880,7 +880,9 @@ Type TypeChecker::applyUnboundGenericArguments(
     auto genericSig = genericEnv->getGenericSignature();
     for (auto gp : genericSig->getGenericParams()) {
       subs[gp->getCanonicalType()->castTo<GenericTypeParamType>()] =
-        genericEnv->mapTypeIntoContext(gp);
+        (resolution.usesArchetypes()
+         ? genericEnv->mapTypeIntoContext(gp)
+         : gp);
     }
   }
 

Original file line number	Diff line number	Diff line change
`@@ -880,7 +880,9 @@ Type TypeChecker::applyUnboundGenericArguments(`
`880`	`880`	`auto genericSig = genericEnv->getGenericSignature();`
`881`	`881`	`for (auto gp : genericSig->getGenericParams()) {`
`882`	`882`	`subs[gp->getCanonicalType()->castTo<GenericTypeParamType>()] =`
`883`		`- genericEnv->mapTypeIntoContext(gp);`
	`883`	`+ (resolution.usesArchetypes()`
	`884`	`+ ? genericEnv->mapTypeIntoContext(gp)`
	`885`	`+ : gp);`
`884`	`886`	`}`
`885`	`887`	`}`
`886`	`888`