Cache the value type of a generic param when cloning

Author: Azoy

lib/AST/ASTDumper.cpp

@@ -1277,6 +1277,7 @@ namespace {
         break;
       case GenericTypeParamKind::Value:
         printField((StringRef)"value", "param_kind");
+        printRec(decl->getValueType(), "value_type");
         break;
       }
       printAttributes(decl);

lib/AST/GenericParamList.cpp

@@ -17,6 +17,7 @@
 #include "swift/AST/GenericParamList.h"
 
 #include "swift/AST/ASTContext.h"
+#include "swift/AST/TypeCheckRequests.h"
 #include "swift/AST/TypeRepr.h"
 #include "swift/Basic/Assertions.h"
 
@@ -78,6 +79,12 @@ GenericParamList::clone(DeclContext *dc) const {
         dc, param->getName(), GenericTypeParamDecl::InvalidDepth,
         param->getIndex(), param->getParamKind(), param->getOpaqueTypeRepr());
     newParam->setInherited(param->getInherited().getEntries());
+
+    // Cache the value type computed from the previous param to the new one.
+    ctx.evaluator.cacheOutput(
+        GenericTypeParamDeclGetValueTypeRequest{newParam},
+        param->getValueType());
+
     params.push_back(newParam);
   }
 

test/SILGen/vector_literal.swift

@@ -1,6 +1,6 @@
 // RUN: %target-swift-emit-silgen %s -disable-availability-checking -enable-experimental-feature ValueGenerics | %FileCheck %s
 
-// 123REQUIRES123: swift_feature_ValueGenerics
+// REQUIRES: swift_feature_ValueGenerics
 
 import Synchronization
 

test/Sema/vector.swift

@@ -64,3 +64,19 @@ func foo() {
   sprites = .init(bricks: bricks) // expected-error {{cannot convert value of type 'Vector<1, MySprite>' to expected argument type 'Vector<40, MySprite>'}}
                                   // expected-note@-1 {{arguments to generic parameter 'count' ('1' and '40') are expected to be equal}}
 }
+
+// Make sure the deserialized integer generic argument gets treated as an integer
+// generic argument when we clone the generic param list for extensions.
+extension Vector where Element: ~Copyable {
+  func forEach(_ body: (borrowing Element) -> Void) {
+    for i in 0 ..< count {
+      body(self[i])
+    }
+  }
+
+  func enumerated(_ body: (Int, borrowing Element) -> Void) {
+    for i in 0 ..< count {
+      body(i, self[i])
+    }
+  }
+}