Refactor Expr as class hierarchy instead of union (#524)

This has the benefit of making things much more type-safe, as well as
simplifying destroying member variables.

For now, many of the members are still raw pointers, but they probably
should become unique_ptrs or ordinary values.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/generate-names.cc b/src/generate-names.cc
index f3332d5c..c2c602e7 100644
--- a/src/generate-names.cc
+++ b/src/generate-names.cc
@@ -41,9 +41,9 @@ class NameGenerator : public ExprVisitor::DelegateNop {
   Result VisitModule(Module* module);
 
   // Implementation of ExprVisitor::DelegateNop.
-  Result BeginBlockExpr(Expr* expr) override;
-  Result BeginLoopExpr(Expr* expr) override;
-  Result BeginIfExpr(Expr* expr) override;
+  Result BeginBlockExpr(BlockExpr* expr) override;
+  Result BeginLoopExpr(LoopExpr* expr) override;
+  Result BeginIfExpr(IfExpr* expr) override;
 
  private:
   static bool HasName(StringSlice* str);
@@ -135,18 +135,18 @@ void NameGenerator::GenerateAndBindLocalNames(BindingHash* bindings,
   }
 }
 
-Result NameGenerator::BeginBlockExpr(Expr* expr) {
+Result NameGenerator::BeginBlockExpr(BlockExpr* expr) {
   MaybeGenerateName("$B", label_count_++, &expr->block->label);
   return Result::Ok;
 }
 
-Result NameGenerator::BeginLoopExpr(Expr* expr) {
-  MaybeGenerateName("$L", label_count_++, &expr->loop->label);
+Result NameGenerator::BeginLoopExpr(LoopExpr* expr) {
+  MaybeGenerateName("$L", label_count_++, &expr->block->label);
   return Result::Ok;
 }
 
-Result NameGenerator::BeginIfExpr(Expr* expr) {
-  MaybeGenerateName("$I", label_count_++, &expr->if_.true_->label);
+Result NameGenerator::BeginIfExpr(IfExpr* expr) {
+  MaybeGenerateName("$I", label_count_++, &expr->true_->label);
   return Result::Ok;
 }