public override AST.Node ToAST(Env env)
{
/// An iteration statement is a block.
env.PushBlockScope();
/// Check the expressions.
/// An omitted expression-2 is replaced by a nonzero constant.
var i = initExpr != null?initExpr.ToAST(env) : (initDecl != null ? initDecl.ToAST(env) : null);
var p = pred != null?pred.ToASTExpr(env) : new AST.ConstIntExpr(TInt.Instance, 1, env.ASTEnv);
var q = iter != null?iter.ToAST(env) : null;
/// The controlling expression of a iteration statement shall have scalar type.
if (!p.Type.IsScalar)
{
throw new ETypeError(Pos, "the controlling expression of iteration statement should have scalar type");
}
/// Add this loop to the environment.
env.PushLoop(this);
var b = body.ToASTCompoundStmt(env);
env.PopBreakable();
env.PopScope();
return(new AST.For(breakLabel, continueLabel, secondPlusLabel, firstLabel, i, p, q, b));
}
public override AST.Node ToAST(Env env)
{
/// An iteration statement is a block.
env.PushBlockScope();
/// The controlling expression should have scalar type.
AST.Expr e = expr.ToASTExpr(env);
if (!e.Type.IsScalar)
{
throw new ETypeError(Pos, "the controlling expression of iteration statement should have scalar type");
}
/// The loop body is also a block.
env.PushBlockScope();
/// Add this loop to the environemnt.
env.PushLoop(this);
var b = body.ToASTCompoundStmt(env);
env.PopBreakable();
env.PopScope();
env.PopScope();
return(new AST.While(breakLabel, continueLabel, secondPlusLabel, firstLabel, e, b));
}
public override AST.Node ToAST(Env env)
{
env.PushBlockScope();
env.PushBlockScope();
env.PushLoop(this);
var b = body.ToASTCompoundStmt(env);
env.PopBreakable();
env.PopScope();
AST.Expr e = expr.ToASTExpr(env);
if (!e.Type.IsScalar)
{
throw new ETypeError(Pos, "the controlling expression of iteration statement should be have scalar type");
}
env.PopScope();
return(new AST.Do(breakLabel, continueLabel, secondPlusLabel, firstLabel, e, b));
}
public override AST.Node ToAST(Env env)
{
/// The controlling expression shall have integer type.
e = expr.ToASTExpr(env);
if (!e.Type.IsInteger && e.Type.Kind != TKind.ENUM)
{
throw new ETypeError(Pos, "the controlling expression of switch statement shall have integer type");
}
/// Integer promotions are performed on the controlling expression.
e = e.IntPromote();
env.PushSwitch(this);
/// Semantic check the statment.
AST.Node s = stmt.ToAST(env);
env.PopBreakable();
return(new AST.Switch(breakLabel, cases, defaultLabel, e, s));
}