[strong] Implement static restrictions on switch statement

src/ast.h

Index: src/ast.h
diff --git a/src/ast.h b/src/ast.h
index 7bfa02178faabb6e09af3c3f8d8f303393da88d1..42fffd570294454a8613de408b9efaba38fa6d17 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -280,6 +280,7 @@ class Statement : public AstNode {
 
   bool IsEmpty() { return AsEmptyStatement() != NULL; }
   virtual bool IsJump() const { return false; }
+  virtual bool IsStrongSwitchTerminatingStatement() const { return false; }

[rossberg, 2015/04/14 20:19:49]

I'm tempted to get rid of this and just use IsJump. AFAICS the only remaining
difference is IfStatement. I'm willing to tweak the spec to cover that. Adapting
the preparser should be straightforward as well.

[conradw, 2015/04/15 11:40:03]

Done.

 };
 
 
@@ -514,6 +515,9 @@ class Block FINAL : public BreakableStatement {
     return !statements_.is_empty() && statements_.last()->IsJump()
         && labels() == NULL;  // Good enough as an approximation...
   }
+  bool IsStrongSwitchTerminatingStatement() const OVERRIDE {
+    return IsJump();
+  }
 
   Scope* scope() const { return scope_; }
   void set_scope(Scope* scope) { scope_ = scope; }
@@ -1019,6 +1023,7 @@ class ExpressionStatement FINAL : public Statement {
   void set_expression(Expression* e) { expression_ = e; }
   Expression* expression() const { return expression_; }
   bool IsJump() const OVERRIDE { return expression_->IsThrow(); }
+  bool IsStrongSwitchTerminatingStatement() const OVERRIDE { return IsJump(); }
 
  protected:
   ExpressionStatement(Zone* zone, Expression* expression, int pos)
@@ -1032,6 +1037,7 @@ class ExpressionStatement FINAL : public Statement {
 class JumpStatement : public Statement {
  public:
   bool IsJump() const FINAL { return true; }
+  bool IsStrongSwitchTerminatingStatement() const FINAL { return true; }
 
  protected:
   explicit JumpStatement(Zone* zone, int pos) : Statement(zone, pos) {}