/// <summary>
/// Rewrites the children of the given block expression.
/// </summary>
/// <param name="blockExpression"></param>
public override void RewriteChildren(BlockExpression blockExpression) {
var block = blockExpression.BlockStatement as BlockStatement;
Contract.Assume(block != null);
if (this.scopesWithCapturedLocals.ContainsKey(block)) {
this.AllocateClosureFor(block, block.Statements, () => {
base.RewriteChildren(block);
blockExpression.Expression = this.Rewrite(blockExpression.Expression);
});
} else
base.RewriteChildren(blockExpression);
}
/// <summary>
/// Visits the specified block expression.
/// </summary>
/// <param name="blockExpression">The block expression.</param>
public override void Visit(IBlockExpression blockExpression)
{
BlockExpression mutableBlockExpression = new BlockExpression(blockExpression);
this.resultExpression = this.myCodeCopier.DeepCopy(mutableBlockExpression);
}
/// <summary>
/// Visits the specified block expression.
/// </summary>
/// <param name="blockExpression">The block expression.</param>
/// <returns></returns>
protected virtual IExpression DeepCopy(BlockExpression blockExpression)
{
blockExpression.BlockStatement = (IBlockStatement)this.Substitute(blockExpression.BlockStatement);
blockExpression.Expression = Substitute(blockExpression.Expression);
blockExpression.Type = this.Substitute(blockExpression.Type);
return blockExpression;
}
public override void RewriteChildren(ContractElement contractElement) {
base.RewriteChildren(contractElement);
var be = contractElement.Condition as IBlockExpression;
if (be != null) {
var lb = new LocalBinder(this.host);
contractElement.Condition = lb.Rewrite(contractElement.Condition);
if (lb.localDeclarations.Any()) {
var be2 = new BlockExpression() {
BlockStatement = new BlockStatement() {
Statements = lb.localDeclarations,
},
Expression = contractElement.Condition,
};
contractElement.Condition = be2;
}
}
}
/// <summary>
/// The source expression "new C(){ f1 = e1, f2 = e2, ... }" (where the f's can be fields
/// or properties) turns into "cgl = new C(); cgl.f1 = e1; cg1.f2 = e2; ...".
/// ("cgl" means "compiler-generated local".)
/// Turn it into a block expression whose Statements are the statements above (but where
/// the first one becomes a local declaration statement), and with an Expression that is
/// just the local, cgl', where cgl' is a freshly created local.
/// </summary>
private bool ReplaceCompilerGeneratedLocalUsedForInitializersPattern(BlockStatement b) {
Contract.Requires(b != null);
bool replacedPattern = false;
var statements = b.Statements;
for (int i = 0; i < statements.Count - 1; i++) {
var expressionStatement = statements[i] as ExpressionStatement;
if (expressionStatement == null) continue;
var assignment = expressionStatement.Expression as Assignment;
if (assignment == null) continue;
var local = assignment.Target.Definition as ILocalDefinition;
if (local == null || local is CapturedLocalDefinition) continue;
if (this.numberOfAssignmentsToLocal[local] != 1) continue;
if (this.sourceLocationProvider != null) {
bool isCompilerGenerated;
var sourceName = this.sourceLocationProvider.GetSourceNameFor(local, out isCompilerGenerated);
if (!isCompilerGenerated) continue;
}
var createObject = assignment.Source as ICreateObjectInstance;
if (createObject == null) continue;
if (!this.singleUseExpressionChecker.ExpressionCanBeMovedAndDoesNotReference(assignment.Source, local)) continue;
var j = 1;
while (i + j < statements.Count - 1 && IsAssignmentToFieldOrProperty(local, statements[i + j])) j++;
if (j == 1) continue;
if (this.numberOfReferencesToLocal[local] != (uint)j) continue;
Contract.Assume(i + j < statements.Count); //i < statements.Count-1 and (j == 1 or the loop above established i+j < statements.Count-1)
Contract.Assume(statements[i + j] != null);
if (LocalFinder.LocalOccursIn(statements[i+j], local) && this.singleAssignmentReferenceFinder.LocalCanBeReplacedIn(statements[i + j], local)) {
var newLocal = new LocalDefinition() {
Name = this.host.NameTable.GetNameFor(local.Name.Value + "_prime"),
MethodDefinition = local.MethodDefinition,
Type = local.Type,
};
var lds = new LocalDeclarationStatement() {
InitialValue = assignment.Source,
LocalVariable = newLocal,
};
var stmts = new List<IStatement>(j) { lds, };
var boundExpression = new BoundExpression() { Definition = newLocal, Instance = null, Type = newLocal.Type, };
foreach (var s in statements.GetRange(i + 1, j - 1)) {
Contract.Assume(s != null);
this.singleAssignmentLocalReplacer.Replace(boundExpression, local, s);
stmts.Add(s);
}
var blockExpression = new BlockExpression() {
BlockStatement = new BlockStatement() {
Statements = stmts,
},
Expression = new BoundExpression() { Definition = newLocal, Instance = null, Type = newLocal.Type, },
Type = newLocal.Type,
};
if (this.singleAssignmentLocalReplacer.Replace(blockExpression, local, statements[i + j])) {
this.numberOfAssignmentsToLocal[newLocal] = 1;
this.numberOfReferencesToLocal[newLocal] = (uint)j;
this.numberOfAssignmentsToLocal[local]--;
this.numberOfReferencesToLocal[local] = 0;
statements.RemoveRange(i, j);
replacedPattern = true;
} else
Contract.Assume(false); // replacement should succeed since the combination of LocalOccursIn and LocalCanBeReplacedIn returned true
}
}
return replacedPattern;
}
private IExpression/*?*/ GetFilterCondition(DecompiledBlock block) {
Contract.Requires(block != null);
BlockExpression result = null;
List<IStatement> statements = null;
foreach (var statement in block.Statements) {
var nestedBlock = statement as DecompiledBlock;
if (nestedBlock != null) {
var nestedResult = this.GetFilterCondition(nestedBlock);
if (nestedResult != null) {
if (result == null) return nestedResult;
result.Expression = nestedResult;
return result;
}
} else {
var endFilter = statement as EndFilter;
if (endFilter != null) {
if (result == null) return endFilter.FilterResult;
result.Expression = endFilter.FilterResult;
return result;
}
}
if (statements == null) {
statements = new List<IStatement>();
result = new BlockExpression() { BlockStatement = new BlockStatement() { Statements = statements } };
}
statements.Add(statement);
}
if (result != null && result.Expression == CodeDummy.Expression) return null;
return result;
}
private static IExpression ExtractFilterCondition(BasicBlock handlerBlock)
{
int endFilterIndex = -1;
IExpression result = CodeDummy.Expression;
for (int i = 0; i < handlerBlock.Statements.Count; i++) {
var endFilter = handlerBlock.Statements[i] as EndFilter;
if (endFilter != null) {
result = endFilter.FilterResult;
endFilterIndex = i;
break;
}
}
if (endFilterIndex < 0) return result;
if (endFilterIndex == 0) {
handlerBlock.Statements.RemoveAt(0);
return result;
}
var blockExpression = new BlockExpression();
blockExpression.BlockStatement = ExtractAsBasicBlock(handlerBlock, 0, endFilterIndex);
blockExpression.Expression = result;
blockExpression.Type = result.Type;
handlerBlock.Statements.RemoveRange(0, endFilterIndex+1);
return blockExpression;
}
/// <summary>
/// Rewrites the children of the given block expression.
/// </summary>
public virtual void RewriteChildren(BlockExpression blockExpression)
{
this.RewriteChildren((Expression)blockExpression);
blockExpression.BlockStatement = this.Rewrite((BlockStatement)blockExpression.BlockStatement);
blockExpression.Expression = this.Rewrite(blockExpression.Expression);
}
/// <summary>
/// Visits the specified block expression.
/// </summary>
/// <param name="blockExpression">The block expression.</param>
public override void Visit(IBlockExpression blockExpression)
{
BlockExpression mutableBlockExpression = blockExpression as BlockExpression;
if (alwaysMakeACopy || mutableBlockExpression == null) mutableBlockExpression = new BlockExpression(blockExpression);
this.resultExpression = this.myCodeMutator.Visit(mutableBlockExpression);
}
/// <summary>
/// Visits the specified block expression.
/// </summary>
/// <param name="blockExpression">The block expression.</param>
/// <returns></returns>
public virtual IExpression Visit(BlockExpression blockExpression)
{
blockExpression.BlockStatement = this.Visit(blockExpression.BlockStatement);
blockExpression.Expression = Visit(blockExpression.Expression);
blockExpression.Type = this.Visit(blockExpression.Type);
return blockExpression;
}
