Merge pull request #11077 from slavapestov/a-dave-abrahams-special-4.0

slavapestov · web-flow · commit 9ee66454cd2f · 2017-07-20T13:09:56.000-07:00
AST: Check return value of ProtocolConformance::getTypeWitness() [4.0]
diff --git a/lib/AST/GenericSignatureBuilder.cpp b/lib/AST/GenericSignatureBuilder.cpp
@@ -1720,6 +1720,7 @@ static void concretizeNestedTypeFromConcreteParent(
     witnessType =
       conformance.getConcrete()
         ->getTypeWitness(assocType, builder.getLazyResolver());
+    if (!witnessType) return;
   } else {
     witnessType = DependentMemberType::get(concreteParent, assocType);
   }

Original file line number	Diff line number	Diff line change
`@@ -1720,6 +1720,7 @@ static void concretizeNestedTypeFromConcreteParent(`
`1720`	`1720`	`witnessType =`
`1721`	`1721`	`conformance.getConcrete()`
`1722`	`1722`	`->getTypeWitness(assocType, builder.getLazyResolver());`
	`1723`	`+ if (!witnessType) return;`
`1723`	`1724`	`} else {`
`1724`	`1725`	`witnessType = DependentMemberType::get(concreteParent, assocType);`
`1725`	`1726`	`}`