[Runtime] Properly unique foreign witness tables.

DougGregor · DougGregor · commit cacd72f18cd7 · 2018-12-13T13:43:36.000-08:00
The Name field of a type descriptor is not the appropriate
way to compare types for uniquing. Instead, use TypeContextIdentity.

Fixes rdar://problem/46685973.
diff --git a/stdlib/public/runtime/Metadata.cpp b/stdlib/public/runtime/Metadata.cpp
@@ -3669,7 +3669,8 @@ namespace {
     int compareWithKey(const Key other) const {
       if (auto r = comparePointers(other.protocol, key.protocol))
         return r;
-      return strcmp(other.type->Name.get(), key.type->Name.get());
+
+      return TypeContextIdentity(other.type).compare(TypeContextIdentity(key.type));
     }
 
     static size_t getExtraAllocationSize(const Key,

Original file line number	Diff line number	Diff line change
`@@ -3669,7 +3669,8 @@ namespace {`
`3669`	`3669`	`int compareWithKey(const Key other) const {`
`3670`	`3670`	`if (auto r = comparePointers(other.protocol, key.protocol))`
`3671`	`3671`	`return r;`
`3672`		`- return strcmp(other.type->Name.get(), key.type->Name.get());`
	`3672`	`+`
	`3673`	`+ return TypeContextIdentity(other.type).compare(TypeContextIdentity(key.type));`
`3673`	`3674`	`}`
`3674`	`3675`
`3675`	`3676`	`static size_t getExtraAllocationSize(const Key,`