Merge pull request #59996 from ahoppen/pr/more-dumping

Support dumping of null ASTNodes and ConstraintLocatorBuilder

Author: ahoppen

include/swift/Sema/ConstraintLocator.h

@@ -191,6 +191,11 @@ class ConstraintLocator : public llvm::FoldingSetNode {
     bool isClosureResult() const {
       return getKind() == PathElementKind::ClosureResult;
     }
+
+    void dump(raw_ostream &out) const LLVM_ATTRIBUTE_USED;
+    SWIFT_DEBUG_DUMP {
+      dump(llvm::errs());
+    }
   };
 
   /// Return the summary flags for an entire path.
@@ -1256,6 +1261,12 @@ class ConstraintLocatorBuilder {
 
     return None;
   }
+
+  /// Produce a debugging dump of this locator.
+  SWIFT_DEBUG_DUMPER(dump(SourceManager *SM));
+  SWIFT_DEBUG_DUMPER(dump(ConstraintSystem *CS));
+
+  void dump(SourceManager *SM, raw_ostream &OS) const LLVM_ATTRIBUTE_USED;
 };
 
 } // end namespace constraints

lib/AST/ASTNode.cpp

@@ -109,7 +109,9 @@ void ASTNode::walk(ASTWalker &Walker) {
 }
 
 void ASTNode::dump(raw_ostream &OS, unsigned Indent) const {
-  if (auto S = dyn_cast<Stmt*>())
+  if (isNull())
+    OS << "(null)";
+  else if (auto S = dyn_cast<Stmt*>())
     S->dump(OS, /*context=*/nullptr, Indent);
   else if (auto E = dyn_cast<Expr*>())
     E->dump(OS, Indent);