lookupDefaultLiteralType doesn't need a TypeChecler

Author: hamishknight

lib/Sema/TypeCheckExpr.cpp

@@ -638,15 +638,16 @@ Expr *TypeChecker::buildAutoClosureExpr(DeclContext *DC, Expr *expr,
   return closure;
 }
 
-static Type lookupDefaultLiteralType(TypeChecker &TC, const DeclContext *dc,
+static Type lookupDefaultLiteralType(const DeclContext *dc,
                                      StringRef name) {
+  auto &ctx = dc->getASTContext();
   auto lookupOptions = defaultUnqualifiedLookupOptions;
   if (isa<AbstractFunctionDecl>(dc))
     lookupOptions |= NameLookupFlags::KnownPrivate;
-  auto lookup = TC.lookupUnqualified(dc->getModuleScopeContext(),
-                                     TC.Context.getIdentifier(name),
-                                     SourceLoc(),
-                                     lookupOptions);
+  auto lookup = TypeChecker::lookupUnqualified(dc->getModuleScopeContext(),
+                                               ctx.getIdentifier(name),
+                                               SourceLoc(),
+                                               lookupOptions);
   TypeDecl *TD = lookup.getSingleTypeResult();
   if (!TD)
     return Type();
@@ -709,15 +710,12 @@ swift::DefaultTypeRequest::evaluate(Evaluator &evaluator,
   if (!name)
     return nullptr;
 
-  // FIXME: Creating a whole type checker just to do lookup is unnecessary.
-  TypeChecker &tc = TypeChecker::createForContext(dc->getASTContext());
-
   Type type;
   if (performLocalLookup)
-    type = lookupDefaultLiteralType(tc, dc, name);
+    type = lookupDefaultLiteralType(dc, name);
 
   if (!type)
-    type = lookupDefaultLiteralType(tc, tc.getStdlibModule(dc), name);
+    type = lookupDefaultLiteralType(TypeChecker::getStdlibModule(dc), name);
 
   // Strip off one level of sugar; we don't actually want to print
   // the name of the typealias itself anywhere.

lib/Sema/TypeChecker.cpp

@@ -209,7 +209,7 @@ Type TypeChecker::getObjectLiteralParameterType(ObjectLiteralExpr *expr,
 }
 
 ModuleDecl *TypeChecker::getStdlibModule(const DeclContext *dc) {
-  if (auto *stdlib = Context.getStdlibModule()) {
+  if (auto *stdlib = dc->getASTContext().getStdlibModule()) {
     return stdlib;
   }
 

lib/Sema/TypeChecker.h

@@ -1702,7 +1702,7 @@ class TypeChecker final : public LazyResolver {
   ///
   /// This is "Swift", if that module is imported, or the current module if
   /// we're parsing the standard library.
-  ModuleDecl *getStdlibModule(const DeclContext *dc);
+  static ModuleDecl *getStdlibModule(const DeclContext *dc);
 
   /// \name Lazy resolution.
   ///