[ASTPrinter] Put desugaring constraints for existential types behind a

PrintOptions flag that is only enabled for interface printing.
voidref · May 24, 2022 · 38dfb99 · 38dfb99
1 parent e9c14cd
commit 38dfb99
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/include/swift/AST/PrintOptions.h b/include/swift/AST/PrintOptions.h
@@ -285,6 +285,9 @@ struct PrintOptions {
   /// types.
   bool PrintExplicitAny = false;
 
+  /// Whether to desugar the constraint for an existential type.
+  bool DesugarExistentialConstraint = false;
+
   /// Whether to skip keywords with a prefix of underscore such as __consuming.
   bool SkipUnderscoredKeywords = false;
 

diff --git a/lib/AST/ASTPrinter.cpp b/lib/AST/ASTPrinter.cpp
@@ -156,6 +156,7 @@ PrintOptions PrintOptions::printSwiftInterfaceFile(ModuleDecl *ModuleToPrint,
   result.AlwaysTryPrintParameterLabels = true;
   result.PrintSPIs = printSPIs;
   result.PrintExplicitAny = true;
+  result.DesugarExistentialConstraint = true;
 
   // We should print __consuming, __owned, etc for the module interface file.
   result.SkipUnderscoredKeywords = false;
@@ -6216,7 +6217,11 @@ class TypePrinter : public TypeVisitor<TypePrinter> {
     // interfaces. Verifying that the underlying type of a
     // protocol typealias is a constriant type is fundamentally
     // circular, so the desugared type should be written in source.
-    visit(T->getConstraintType()->getDesugaredType());
+    if (Options.DesugarExistentialConstraint) {
+      visit(T->getConstraintType()->getDesugaredType());
+    } else {
+      visit(T->getConstraintType());
+    }
   }
 
   void visitLValueType(LValueType *T) {