public override AstNode Visit(IfStatement node)
{
// Begin the node.
builder.BeginNode(node);
// Get the condition, then and else.
Expression condition = node.GetCondition();
AstNode thenNode = node.GetThen();
AstNode elseNode = node.GetElse();
IChelaType condType = condition.GetNodeType();
// Visit the condition.
condition.Accept(this);
if(condType != ChelaType.GetBoolType()) // Read variables values.
Cast(node, condition.GetNodeValue(), condType, ChelaType.GetBoolType());
// Create the basic blocks.
BasicBlock thenBlock = CreateBasicBlock();
BasicBlock elseBlock = CreateBasicBlock();
thenBlock.SetName("then");
if(elseNode != null)
elseBlock.SetName("else");
else
elseBlock.SetName("merge");
// Perform the branch.
builder.CreateBr(thenBlock, elseBlock);
builder.SetBlock(thenBlock);
// Visit the then statement.
thenNode.Accept(this);
// Update the then block.
thenBlock = builder.GetBlock();
// Write the else block.
if(elseNode != null)
{
// Set the current block.
builder.SetBlock(elseBlock);
// Visit the else statement.
elseNode.Accept(this);
// Update the else block.
elseBlock = builder.GetBlock();
}
if(thenBlock.IsLastTerminator() && elseBlock.IsLastTerminator())
return builder.EndNode();
// Get or create the merge block.
BasicBlock mergeBlock = null;
if(elseNode != null)
{
mergeBlock = CreateBasicBlock();
mergeBlock.SetName("merge");
}
else
{
mergeBlock = elseBlock;
}
// Write the block terminators.
if(!thenBlock.IsLastTerminator())
{
builder.SetBlock(thenBlock);
builder.CreateJmp(mergeBlock);
}
if(elseNode != null && !elseBlock.IsLastTerminator())
{
builder.SetBlock(elseBlock);
builder.CreateJmp(mergeBlock);
}
// Continue.
builder.SetBlock(mergeBlock);
return builder.EndNode();
}
public override AstNode Visit(IfStatement node)
{
// Get the condition, then and else.
Expression cond = node.GetCondition();
AstNode thenNode = node.GetThen();
AstNode elseNode = node.GetElse();
// Visit the condition, then and else.
cond.Accept(this);
thenNode.Accept(this);
if(elseNode != null)
elseNode.Accept(this);
// Check the condition type.
IChelaType condType = cond.GetNodeType();
if(condType != ChelaType.GetBoolType() &&
Coerce(condType, ChelaType.GetBoolType()) != ChelaType.GetBoolType())
Error(node, "condition must be a boolean expression.");
return node;
}
