protected virtual BoundStatement RewriteBlockStatement(BoundBlockStatement node)
{
ImmutableArray <BoundStatement> .Builder builder = null;
for (var i = 0; i < node.Statements.Length; ++i)
{
var statement = RewriteStatement(node.Statements[i]);
if (statement != node.Statements[i])
{
if (builder == null)
{
builder = ImmutableArray.CreateBuilder <BoundStatement>(node.Statements.Length);
for (var j = 0; j < i; ++j)
{
builder.Add(node.Statements[j]);
}
}
}
if (builder != null)
{
builder.Add(statement);
}
}
if (builder == null)
{
return(node);
}
return(new BoundBlockStatement(builder.MoveToImmutable()));
}
public List <BasicBlock> Build(BoundBlockStatement blockStatement)
{
foreach (var statement in blockStatement.Statements)
{
switch (statement.Kind)
{
case BoundNodeKind.ExpressionStatement:
case BoundNodeKind.VariableDeclarationStatement:
//add to current block
_statements.Add(statement);
break;
case BoundNodeKind.GotoStatement:
case BoundNodeKind.ConditionalGotoStatement:
case BoundNodeKind.ReturnStatement:
//end block
_statements.Add(statement);
StartBlock();
break;
case BoundNodeKind.LabelStatement:
//start block
StartBlock();
_statements.Add(statement);
break;
default:
throw new Exception($"Unexpected statement: {statement.Kind}");
}
}
EndBlock();
return(_blocks.ToList());
}
public static ControlFlowGraph Create(BoundBlockStatement body)
{
var basicBlockBuiler = new BasicBlockBuilder();
var blocks = basicBlockBuiler.Build(body);
var graphBuilder = new GraphBuilder();
return(graphBuilder.Build(blocks));
}
public static bool AllPathsReturn(BoundBlockStatement body)
{
var graph = Create(body);
foreach (var branch in graph.End.Incoming)
{
var s = branch.From.Statements.Last();
if (s.Kind != BoundNodeKind.ReturnStatement)
{
return(false);
}
}
return(true);
}
private static void WriteBlockStatement(BoundBlockStatement node, IndentedTextWriter writer)
{
writer.WritePunctuation(SyntaxKind.OpenBraceToken);
writer.WriteLine();
writer.Indent++;
foreach (var s in node.Statements)
{
s.WriteTo(writer);
}
writer.Indent--;
writer.WritePunctuation(SyntaxKind.CloseBraceToken);
writer.WriteLine();
}
public BoundProgram(BoundBlockStatement statement, DiagnosticBag diagnostics, ImmutableDictionary <FunctionSymbol, BoundBlockStatement> functionBodies)
{
Statement = statement;
Diagnostics = diagnostics;
FunctionBodies = functionBodies;
}
