/// <summary>
/// Decompile the IL operations of this method body into a block of statements.
/// </summary>
protected override IBlockStatement GetBlock()
{
var block = new DecompiledBlock(0, this.ilMethodBody.Size, new Sublist <BasicBlock <Instruction> >(this.cdfg.AllBlocks, 0, this.cdfg.AllBlocks.Count), isLexicalScope: true);
this.CreateExceptionBlocks(block);
bool addDeclarations = true;
if (this.localScopeProvider != null)
{
var scopes = new List <ILocalScope>(this.localScopeProvider.GetLocalScopes(this.ilMethodBody));
if (scopes.Count > 0)
{
this.CreateLexicalScopes(block, new Sublist <ILocalScope>(scopes, 0, scopes.Count));
addDeclarations = false;
}
}
if (addDeclarations)
{
int counter = 0;
foreach (var local in this.ilMethodBody.LocalVariables)
{
Contract.Assume(local != null);
Contract.Assume(counter <= block.Statements.Count);
block.Statements.Insert(counter++, new LocalDeclarationStatement()
{
LocalVariable = this.GetLocalWithSourceName(local)
});
}
}
new InstructionParser(this).Traverse(block);
new SwitchReplacer(this).Traverse(block);
DeleteNops(block);
DeleteLocalAssignedLocal(block);
new PatternReplacer(this, block).Traverse(block);
new TryCatchReplacer(this, block).Traverse(block);
new RemoveNonLexicalBlocks().Traverse(block);
new DeclarationUnifier(this).Traverse(block);
new IfThenElseReplacer(this).Traverse(block);
if ((this.options & DecompilerOptions.Loops) != 0)
{
new WhileLoopReplacer(this).Traverse(block);
new ForLoopReplacer(this).Traverse(block);
}
new UnreferencedLabelRemover(this).Traverse(block);
new LockReplacer(this).Traverse(block);
new BlockFlattener().Traverse(block);
this.RemoveRedundantFinalReturn(block);
var result = new CompilationArtifactRemover(this).Rewrite(block);
if ((this.options & DecompilerOptions.AnonymousDelegates) != 0)
{
bool didNothing;
result = new AnonymousDelegateInserter(this).InsertAnonymousDelegates(result, out didNothing);
if (!didNothing)
{
new DeclarationUnifier(this).Traverse(result);
}
}
return(result);
}
private bool RemoveEndFinallyFrom(DecompiledBlock block, LabeledStatement labelToGoto)
{
Contract.Requires(block != null);
Contract.Requires(labelToGoto != null);
for (int i = 0; i < block.Statements.Count; i++)
{
if (block.Statements[i] is EndFinally)
{
var gotoFinally = new GotoStatement()
{
TargetStatement = labelToGoto
};
block.Statements[i] = gotoFinally;
var gotos = new List <IGotoStatement>(1);
gotos.Add(gotoFinally);
this.gotosThatTarget[(uint)labelToGoto.Label.UniqueKey] = gotos;
return(true);
}
var nestedBlock = block.Statements[i] as DecompiledBlock;
if (nestedBlock != null && this.RemoveEndFinallyFrom(nestedBlock, labelToGoto))
{
return(true);
}
}
return(false);
}
private void CreateExceptionBlocks(DecompiledBlock block)
{
Contract.Requires(block != null);
if (IteratorHelper.EnumerableIsEmpty(this.ilMethodBody.OperationExceptionInformation))
{
return;
}
List <IOperationExceptionInformation> handlers = new List <IOperationExceptionInformation>(this.ilMethodBody.OperationExceptionInformation);
handlers.Sort(CompareHandlers);
foreach (var exInfo in handlers)
{
Contract.Assume(exInfo != null);
this.CreateNestedBlock(block, exInfo.TryStartOffset, exInfo.TryEndOffset);
if (exInfo.HandlerKind == HandlerKind.Filter)
{
this.CreateNestedBlock(block, exInfo.FilterDecisionStartOffset, exInfo.HandlerEndOffset);
}
else
{
this.CreateNestedBlock(block, exInfo.HandlerStartOffset, exInfo.HandlerEndOffset);
}
}
}
private void AddLocalsAndConstants(DecompiledBlock block, ILocalScope scope)
{
Contract.Requires(block != null);
Contract.Requires(scope != null);
Contract.Requires(this.localScopeProvider != null);
bool isLexicalScope = false;
int counter = 0;
foreach (var local in this.localScopeProvider.GetConstantsInScope(scope))
{
Contract.Assume(local != null);
var localVariable = this.GetLocalWithSourceName(local);
Contract.Assume(counter <= block.Statements.Count);
block.Statements.Insert(counter++, new LocalDeclarationStatement()
{
LocalVariable = localVariable
});
}
foreach (var local in this.localScopeProvider.GetVariablesInScope(scope))
{
Contract.Assume(local != null);
var localVariable = this.GetLocalWithSourceName(local);
Contract.Assume(counter <= block.Statements.Count);
block.Statements.Insert(counter++, new LocalDeclarationStatement()
{
LocalVariable = localVariable
});
}
if (isLexicalScope)
{
block.IsLexicalScope = true;
}
}
internal TryCatchReplacer(SourceMethodBody sourceMethodBody, DecompiledBlock block)
{
Contract.Requires(sourceMethodBody != null);
Contract.Requires(block != null);
this.host = sourceMethodBody.host; Contract.Assume(sourceMethodBody.host != null);
this.gotosThatTarget = sourceMethodBody.gotosThatTarget; Contract.Assume(this.gotosThatTarget != null);
this.unconditionalBranchRemover.gotosThatTarget = sourceMethodBody.gotosThatTarget;
Contract.Assume(sourceMethodBody.ilMethodBody != null);
foreach (var exInfo in sourceMethodBody.ilMethodBody.OperationExceptionInformation)
{
var tryCatchF = this.tryCatchFinallyMap.Find(exInfo.TryStartOffset, exInfo.TryEndOffset);
if (tryCatchF == null)
{
tryCatchF = new TryCatchFinallyStatement();
this.tryCatchFinallyMap.Add(exInfo.TryStartOffset, exInfo.TryEndOffset, tryCatchF);
}
if (exInfo.HandlerKind == HandlerKind.Filter)
{
this.tryCatchFinallyMap.Add(exInfo.FilterDecisionStartOffset, exInfo.HandlerEndOffset, tryCatchF);
this.handlerMap.Add(exInfo.FilterDecisionStartOffset, exInfo.HandlerEndOffset, exInfo);
}
this.tryCatchFinallyMap.Add(exInfo.HandlerStartOffset, exInfo.HandlerEndOffset, tryCatchF);
this.handlerMap.Add(exInfo.HandlerStartOffset, exInfo.HandlerEndOffset, exInfo);
}
}
private void RemoveLocalDeclarationOf(ILocalDefinition exceptionContainer, DecompiledBlock block)
{
Contract.Requires(exceptionContainer != null);
Contract.Requires(block != null);
this.localDeclarationRemover.localVariableToRemove = exceptionContainer;
this.localDeclarationRemover.StopTraversal = false;
this.localDeclarationRemover.Traverse(block);
}
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 void SplitBlock(DecompiledBlock blockToSplit, uint splitOffset, List <IStatement> leftList, List <IStatement> rightList)
{
Contract.Requires(blockToSplit != null);
Contract.Requires(leftList != null);
Contract.Requires(rightList != null);
Contract.Requires(splitOffset >= blockToSplit.StartOffset);
Contract.Requires(splitOffset <= blockToSplit.EndOffset);
var leftBasicBlocks = blockToSplit.GetBasicBlocksForRange(blockToSplit.StartOffset, splitOffset);
Contract.Assume(splitOffset >= blockToSplit.StartOffset);
var leftBlock = new DecompiledBlock(blockToSplit.StartOffset, splitOffset, leftBasicBlocks, isLexicalScope: false);
leftList.Add(leftBlock);
var rightBasicBlocks = blockToSplit.GetBasicBlocksForRange(splitOffset, blockToSplit.EndOffset);
Contract.Assume(splitOffset <= blockToSplit.EndOffset);
var rightBlock = new DecompiledBlock(splitOffset, blockToSplit.EndOffset, rightBasicBlocks, isLexicalScope: false);
rightList.Add(rightBlock);
var n = blockToSplit.Statements.Count;
if (n == 0)
{
return;
}
var leftStatements = leftBlock.Statements = new List <IStatement>();
var rightStatements = rightBlock.Statements = new List <IStatement>();
for (int i = 0; i < n; i++)
{
var nb = blockToSplit.Statements[i] as DecompiledBlock;
Contract.Assume(nb != null);
if (nb.EndOffset <= splitOffset)
{
leftStatements.Add(nb);
}
else if (nb.StartOffset < splitOffset)
{
Contract.Assume(!nb.IsLexicalScope); //lexical scopes are assumed to nest cleanly.
this.SplitBlock(nb, splitOffset, leftStatements, rightStatements);
}
else
{
rightStatements.Add(nb);
}
}
Consolidate(leftBlock);
Consolidate(rightBlock);
}
private void CreateLexicalScopes(DecompiledBlock block, Sublist <ILocalScope> scopes)
{
Contract.Requires(block != null);
Contract.Requires(this.localScopeProvider != null);
for (int i = 0, n = scopes.Count; i < n;)
{
var scope = scopes[i++];
if (scope.Length == 0)
{
continue;
}
var nestedBlock = this.CreateNestedBlock(block, scope.Offset, scope.Offset + scope.Length);
this.AddLocalsAndConstants(nestedBlock, scope);
}
}
private void RemoveRedundantFinalReturn(DecompiledBlock block)
{
Contract.Requires(block != null);
var n = block.Statements.Count;
if (n > 0)
{
var returnStatement = block.Statements[n - 1] as ReturnStatement;
if (returnStatement == null)
{
return;
}
if (this.ilMethodBody.MethodDefinition.Type.TypeCode != PrimitiveTypeCode.Void)
{
var boundExpression = returnStatement.Expression as IBoundExpression;
if (boundExpression == null)
{
return;
}
var local = boundExpression.Definition as ILocalDefinition;
if (local == null)
{
return;
}
if (this.numberOfAssignmentsToLocal[local] > 0)
{
return;
}
this.numberOfReferencesToLocal[local]--;
if (this.numberOfReferencesToLocal[local] == 0 && this.numberOfAssignmentsToLocal[local] == 0)
{
for (int j = 0; j < n - 1; j++)
{
var locDecl = block.Statements[j] as ILocalDeclarationStatement;
if (locDecl != null && locDecl.LocalVariable == local)
{
block.Statements.RemoveAt(j);
n--;
break;
}
}
}
}
block.Statements.RemoveAt(n - 1);
}
}
private void Consolidate(DecompiledBlock block)
{
if (block == null)
{
return;
}
if (block.Statements.Count != 1)
{
return;
}
var nestedBlock = block.Statements[0] as DecompiledBlock;
if (nestedBlock == null)
{
return;
}
Consolidate(nestedBlock);
block.Statements = nestedBlock.Statements;
}
private bool RemovedFilterCondition(DecompiledBlock block)
{
Contract.Requires(block != null);
for (int i = 0; i < block.Statements.Count; i++)
{
var statement = block.Statements[i];
var nestedBlock = statement as DecompiledBlock;
if (nestedBlock != null)
{
if (this.RemovedFilterCondition(nestedBlock))
{
return(true);
}
}
block.Statements.RemoveAt(i);
if (statement is EndFilter)
{
return(true);
}
}
return(false);
}
internal TryCatchReplacer(SourceMethodBody sourceMethodBody, DecompiledBlock block) {
Contract.Requires(sourceMethodBody != null);
Contract.Requires(block != null);
this.host = sourceMethodBody.host; Contract.Assume(sourceMethodBody.host != null);
this.gotosThatTarget = sourceMethodBody.gotosThatTarget; Contract.Assume(this.gotosThatTarget != null);
this.unconditionalBranchRemover.gotosThatTarget = sourceMethodBody.gotosThatTarget;
Contract.Assume(sourceMethodBody.ilMethodBody != null);
foreach (var exInfo in sourceMethodBody.ilMethodBody.OperationExceptionInformation) {
var tryCatchF = this.tryCatchFinallyMap.Find(exInfo.TryStartOffset, exInfo.TryEndOffset);
if (tryCatchF == null) {
tryCatchF = new TryCatchFinallyStatement();
this.tryCatchFinallyMap.Add(exInfo.TryStartOffset, exInfo.TryEndOffset, tryCatchF);
}
if (exInfo.HandlerKind == HandlerKind.Filter) {
this.tryCatchFinallyMap.Add(exInfo.FilterDecisionStartOffset, exInfo.HandlerEndOffset, tryCatchF);
this.handlerMap.Add(exInfo.FilterDecisionStartOffset, exInfo.HandlerEndOffset, exInfo);
}
this.tryCatchFinallyMap.Add(exInfo.HandlerStartOffset, exInfo.HandlerEndOffset, tryCatchF);
this.handlerMap.Add(exInfo.HandlerStartOffset, exInfo.HandlerEndOffset, exInfo);
}
}
private bool RemoveEndFinallyFrom(DecompiledBlock block)
{
Contract.Requires(block != null);
Contract.Assume(block.Statements.Count > 0); //There must be an endfinally
if (block.Statements[block.Statements.Count - 1] is EndFinally)
{
block.Statements.RemoveAt(block.Statements.Count - 1);
return(true);
}
var lastBlock = block.Statements[block.Statements.Count - 1] as DecompiledBlock;
if (lastBlock != null && this.RemoveEndFinallyFrom(lastBlock))
{
return(true);
}
LabeledStatement endFinally = new LabeledStatement()
{
Label = this.host.NameTable.GetNameFor("__endfinally#" + this.endFinallyCounter++), Statement = new EmptyStatement()
};
block.Statements.Add(endFinally);
return(this.RemoveEndFinallyFrom(block, endFinally));
}
private static void ConsolidateScopes(DecompiledBlock cb)
{
Contract.Requires(cb != null);
for (int i = 0; i < cb.Statements.Count; i++)
{
var nb = cb.Statements[i] as DecompiledBlock;
if (nb == null)
{
break;
}
if (nb.Statements.Count == 0)
{
cb.Statements.RemoveAt(i--);
}
}
if (cb.Statements.Count == 1)
{
var nb = cb.Statements[0] as DecompiledBlock;
if (nb != null)
{
cb.Statements = nb.Statements;
}
}
}
private DecompiledBlock CreateNestedBlock(DecompiledBlock block, uint startOffset, uint endOffset)
{
Contract.Requires(block != null);
Contract.Requires(startOffset <= endOffset);
Contract.Ensures(Contract.Result <DecompiledBlock>() != null);
{
nextBlock:
foreach (var statement in block.Statements)
{
var nestedBlock = statement as DecompiledBlock;
if (nestedBlock == null)
{
continue;
}
if (nestedBlock.StartOffset <= startOffset && nestedBlock.EndOffset >= endOffset)
{
block = nestedBlock;
goto nextBlock;
}
}
}
if (block.StartOffset == startOffset && block.EndOffset == endOffset)
{
return(block);
}
//replace block.Statements with three nested blocks, the middle one corresponding to one we have to create
//but keep any declarations.
int n = block.Statements.Count;
var oldStatements = block.Statements;
var newStatements = block.Statements;
int m = 0;
if (n >= 0)
{
while (m < n && oldStatements[m] is LocalDeclarationStatement)
{
m++;
}
if (m < n)
{
newStatements = new List <IStatement>(m + 3);
for (int i = 0; i < m; i++)
{
newStatements.Add(oldStatements[i]);
}
}
}
block.Statements = newStatements;
var basicBlocks = block.GetBasicBlocksForRange(startOffset, endOffset);
var newNestedBlock = new DecompiledBlock(startOffset, endOffset, basicBlocks, isLexicalScope: true);
DecompiledBlock beforeBlock = null;
if (block.StartOffset < startOffset)
{
var basicBlocksBefore = block.GetBasicBlocksForRange(block.StartOffset, startOffset);
Contract.Assume(block.StartOffset < startOffset);
beforeBlock = new DecompiledBlock(block.StartOffset, startOffset, basicBlocksBefore, isLexicalScope: false);
newStatements.Add(beforeBlock);
}
newStatements.Add(newNestedBlock);
DecompiledBlock afterBlock = null;
if (block.EndOffset > endOffset)
{
var basicBlocksAfter = block.GetBasicBlocksForRange(endOffset, block.EndOffset);
Contract.Assume(block.EndOffset > endOffset);
afterBlock = new DecompiledBlock(endOffset, block.EndOffset, basicBlocksAfter, isLexicalScope: false);
newStatements.Add(afterBlock);
}
if (newStatements != oldStatements)
{
//In this case there were already some nested blocks, which happens when there are nested exception blocks
//and we are creating an enclosing lexical block that does not quite coincide with block.
//We now have to populate the newly created blocks with these nested blocks, splitting them if necessary.
for (int i = m; i < n; i++)
{
var nb = oldStatements[i] as DecompiledBlock;
Contract.Assume(nb != null);
if (nb.EndOffset <= startOffset)
{
Contract.Assume(beforeBlock != null);
beforeBlock.Statements.Add(nb);
}
else if (nb.StartOffset < startOffset)
{
Contract.Assume(nb.EndOffset <= endOffset); //nb starts before newNestedBlock but ends inside it.
Contract.Assume(beforeBlock != null);
if (nb.IsLexicalScope)
{
//Lexical scopes are assumed to nest cleanly. But the C# is not playing along when one using statement immediately follows another
//Well fix matters by making nb.EndOffset == startOffset
nb.EndOffset = startOffset;
beforeBlock.Statements.Add(nb);
}
else
{
this.SplitBlock(nb, startOffset, beforeBlock.Statements, newNestedBlock.Statements);
}
}
else if (nb.EndOffset <= endOffset)
{
newNestedBlock.Statements.Add(nb);
}
else if (nb.StartOffset < endOffset)
{
Contract.Assert(nb.EndOffset > endOffset); //nb starts inside newNestedBlock but ends after it.
Contract.Assume(!nb.IsLexicalScope); //lexical scopes are assumed to nest cleanly.
Contract.Assume(afterBlock != null);
this.SplitBlock(nb, endOffset, newNestedBlock.Statements, afterBlock.Statements);
}
else
{
Contract.Assume(afterBlock != null);
afterBlock.Statements.Add(nb);
}
}
//consolidate blocks consisting of a single block
Consolidate(beforeBlock);
Consolidate(newNestedBlock);
Consolidate(afterBlock);
}
return(newNestedBlock);
}
private ILocalDefinition ExtractExceptionContainer(DecompiledBlock nestedBlock, ITypeReference exceptionType) {
Contract.Requires(nestedBlock != null);
Contract.Requires(exceptionType != null);
Contract.Ensures(Contract.Result<ILocalDefinition>() != null);
Contract.Assume(nestedBlock.Statements.Count > 0);
int i = 0;
while (nestedBlock.Statements[i] is LocalDeclarationStatement) { i++; Contract.Assume(i < nestedBlock.Statements.Count); };
var firstStatement = nestedBlock.Statements[i++];
var firstBlock = firstStatement as DecompiledBlock;
while (firstBlock != null) {
Contract.Assume(firstBlock.Statements.Count > 0);
i = 0;
while (firstBlock.Statements[i] is LocalDeclarationStatement) { i++; Contract.Assume(i < firstBlock.Statements.Count); };
firstStatement = firstBlock.Statements[i++];
nestedBlock = firstBlock;
firstBlock = firstStatement as DecompiledBlock;
}
//Ignoring any local declarations inserted for lexical scopes, any decompiled block that does not start with a nested block, starts with a label.
Contract.Assume(firstStatement is LabeledStatement);
if (nestedBlock.Statements.Count > i) {
var exprStatement = nestedBlock.Statements[i] as ExpressionStatement;
if (exprStatement != null) {
nestedBlock.Statements.RemoveRange(i-1, 2);
if (exprStatement.Expression is PopValue) return Dummy.LocalVariable;
var assignment = exprStatement.Expression as Assignment;
if (assignment != null && assignment.Source is PopValue) {
var local = assignment.Target.Definition as ILocalDefinition;
if (local != null) return local; //if not, this is not a recognized code pattern.
}
}
// can't find the local, so just introduce one and leave its value on the stack
var ld = new LocalDefinition() {
Type = exceptionType,
};
var pushStatement = new PushStatement() {
ValueToPush = new BoundExpression() {
Definition = ld,
Type = exceptionType,
},
};
nestedBlock.Statements.Insert(0, pushStatement);
return ld;
} else {
//Valid IL should always have at least one instruction to consume the exception value as well as a branch out of the handler block.
Contract.Assume(false);
return Dummy.LocalVariable;
}
}
private bool RemovedFilterCondition(DecompiledBlock block) {
Contract.Requires(block != null);
for (int i = 0; i < block.Statements.Count; i++) {
var statement = block.Statements[i];
var nestedBlock = statement as DecompiledBlock;
if (nestedBlock != null) {
if (this.RemovedFilterCondition(nestedBlock)) return true;
}
block.Statements.RemoveAt(i);
if (statement is EndFilter) return true;
}
return false;
}
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;
}
/// <summary>
/// Decompile the IL operations of this method body into a block of statements.
/// </summary>
protected override IBlockStatement GetBlock() {
var block = new DecompiledBlock(0, this.ilMethodBody.Size, new Sublist<BasicBlock<Instruction>>(this.cdfg.AllBlocks, 0, this.cdfg.AllBlocks.Count), isLexicalScope: true);
this.CreateExceptionBlocks(block);
bool addDeclarations = true;
if (this.localScopeProvider != null) {
var scopes = new List<ILocalScope>(this.localScopeProvider.GetLocalScopes(this.ilMethodBody));
if (scopes.Count > 0) {
this.CreateLexicalScopes(block, new Sublist<ILocalScope>(scopes, 0, scopes.Count));
addDeclarations = false;
}
}
if (addDeclarations) {
int counter = 0;
foreach (var local in this.ilMethodBody.LocalVariables) {
Contract.Assume(local != null);
Contract.Assume(counter <= block.Statements.Count);
block.Statements.Insert(counter++, new LocalDeclarationStatement() { LocalVariable = this.GetLocalWithSourceName(local) });
}
}
new InstructionParser(this).Traverse(block);
new SwitchReplacer(this).Traverse(block);
DeleteNops(block);
DeleteLocalAssignedLocal(block);
new PatternReplacer(this, block).Traverse(block);
new TryCatchReplacer(this, block).Traverse(block);
new RemoveNonLexicalBlocks().Traverse(block);
new DeclarationUnifier(this).Traverse(block);
new IfThenElseReplacer(this).Traverse(block);
if ((this.options & DecompilerOptions.Loops) != 0) {
new WhileLoopReplacer(this).Traverse(block);
new ForLoopReplacer(this).Traverse(block);
}
new UnreferencedLabelRemover(this).Traverse(block);
new LockReplacer(this).Traverse(block);
new BlockFlattener().Traverse(block);
this.RemoveRedundantFinalReturn(block);
var result = new CompilationArtifactRemover(this).Rewrite(block);
if ((this.options & DecompilerOptions.AnonymousDelegates) != 0) {
bool didNothing;
result = new AnonymousDelegateInserter(this).InsertAnonymousDelegates(result, out didNothing);
if (!didNothing) new DeclarationUnifier(this).Traverse(result);
}
return result;
}
private void CreateExceptionBlocks(DecompiledBlock block) {
Contract.Requires(block != null);
if (IteratorHelper.EnumerableIsEmpty(this.ilMethodBody.OperationExceptionInformation)) return;
List<IOperationExceptionInformation> handlers = new List<IOperationExceptionInformation>(this.ilMethodBody.OperationExceptionInformation);
handlers.Sort(CompareHandlers);
foreach (var exInfo in handlers) {
Contract.Assume(exInfo != null);
this.CreateNestedBlock(block, exInfo.TryStartOffset, exInfo.TryEndOffset);
if (exInfo.HandlerKind == HandlerKind.Filter)
this.CreateNestedBlock(block, exInfo.FilterDecisionStartOffset, exInfo.HandlerEndOffset);
this.CreateNestedBlock(block, exInfo.HandlerStartOffset, exInfo.HandlerEndOffset);
}
}
private void Consolidate(DecompiledBlock block) {
if (block == null) return;
if (block.Statements.Count != 1) return;
var nestedBlock = block.Statements[0] as DecompiledBlock;
if (nestedBlock == null) return;
Consolidate(nestedBlock);
block.Statements = nestedBlock.Statements;
}
private bool RemoveEndFinallyFrom(DecompiledBlock block, LabeledStatement labelToGoto) {
Contract.Requires(block != null);
Contract.Requires(labelToGoto != null);
for (int i = 0; i < block.Statements.Count; i++) {
if (block.Statements[i] is EndFinally) {
var gotoFinally = new GotoStatement() { TargetStatement = labelToGoto };
block.Statements[i] = gotoFinally;
var gotos = new List<IGotoStatement>(1);
gotos.Add(gotoFinally);
this.gotosThatTarget[(uint)labelToGoto.Label.UniqueKey] = gotos;
return true;
}
var nestedBlock = block.Statements[i] as DecompiledBlock;
if (nestedBlock != null && this.RemoveEndFinallyFrom(nestedBlock, labelToGoto)) return true;
}
return false;
}
private void SplitBlock(DecompiledBlock blockToSplit, uint splitOffset, List<IStatement> leftList, List<IStatement> rightList) {
Contract.Requires(blockToSplit != null);
Contract.Requires(leftList != null);
Contract.Requires(rightList != null);
Contract.Requires(splitOffset >= blockToSplit.StartOffset);
Contract.Requires(splitOffset <= blockToSplit.EndOffset);
var leftBasicBlocks = blockToSplit.GetBasicBlocksForRange(blockToSplit.StartOffset, splitOffset);
Contract.Assume(splitOffset >= blockToSplit.StartOffset);
var leftBlock = new DecompiledBlock(blockToSplit.StartOffset, splitOffset, leftBasicBlocks, isLexicalScope: false);
leftList.Add(leftBlock);
var rightBasicBlocks = blockToSplit.GetBasicBlocksForRange(splitOffset, blockToSplit.EndOffset);
Contract.Assume(splitOffset <= blockToSplit.EndOffset);
var rightBlock = new DecompiledBlock(splitOffset, blockToSplit.EndOffset, rightBasicBlocks, isLexicalScope: false);
rightList.Add(rightBlock);
var n = blockToSplit.Statements.Count;
if (n == 0) return;
var leftStatements = leftBlock.Statements = new List<IStatement>();
var rightStatements = rightBlock.Statements = new List<IStatement>();
for (int i = 0; i < n; i++) {
var nb = blockToSplit.Statements[i] as DecompiledBlock;
Contract.Assume(nb != null);
if (nb.EndOffset <= splitOffset) {
leftStatements.Add(nb);
} else if (nb.StartOffset < splitOffset) {
Contract.Assume(!nb.IsLexicalScope); //lexical scopes are assumed to nest cleanly.
this.SplitBlock(nb, splitOffset, leftStatements, rightStatements);
} else {
rightStatements.Add(nb);
}
}
Consolidate(leftBlock);
Consolidate(rightBlock);
}
private void RemoveUnconditionalBranchesToLabelImmediatelyFollowing(TryCatchFinallyStatement trycf, DecompiledBlock followingBlock)
{
Contract.Requires(trycf != null);
while (followingBlock != null)
{
if (followingBlock.Statements.Count == 0)
{
return;
}
var label = followingBlock.Statements[0] as LabeledStatement;
if (label != null)
{
this.unconditionalBranchRemover.StopTraversal = false;
this.unconditionalBranchRemover.targetLabel = label;
this.unconditionalBranchRemover.Traverse(trycf);
var gotos = this.gotosThatTarget.Find((uint)label.Label.UniqueKey);
if (gotos == null || gotos.Count == 0)
{
followingBlock.Statements.RemoveAt(0);
}
return;
}
followingBlock = followingBlock.Statements[0] as DecompiledBlock;
}
}
private void CreateLexicalScopes(DecompiledBlock block, Sublist<ILocalScope> scopes) {
Contract.Requires(block != null);
Contract.Requires(this.localScopeProvider != null);
for (int i = 0, n = scopes.Count; i < n; ) {
var scope = scopes[i++];
if (scope.Length == 0) continue;
var nestedBlock = this.CreateNestedBlock(block, scope.Offset, scope.Offset+scope.Length);
this.AddLocalsAndConstants(nestedBlock, scope);
}
}
private void AddLocalsAndConstants(DecompiledBlock block, ILocalScope scope) {
Contract.Requires(block != null);
Contract.Requires(scope != null);
Contract.Requires(this.localScopeProvider != null);
bool isLexicalScope = false;
int counter = 0;
foreach (var local in this.localScopeProvider.GetConstantsInScope(scope)) {
Contract.Assume(local != null);
var localVariable = this.GetLocalWithSourceName(local);
Contract.Assume(counter <= block.Statements.Count);
block.Statements.Insert(counter++, new LocalDeclarationStatement() { LocalVariable = localVariable });
}
foreach (var local in this.localScopeProvider.GetVariablesInScope(scope)) {
Contract.Assume(local != null);
var localVariable = this.GetLocalWithSourceName(local);
Contract.Assume(counter <= block.Statements.Count);
block.Statements.Insert(counter++, new LocalDeclarationStatement() { LocalVariable = localVariable });
}
if (isLexicalScope) block.IsLexicalScope = true;
}
private bool RemoveEndFinallyFrom(DecompiledBlock block) {
Contract.Requires(block != null);
Contract.Assume(block.Statements.Count > 0); //There must be an endfinally
if (block.Statements[block.Statements.Count-1] is EndFinally) {
block.Statements.RemoveAt(block.Statements.Count-1);
return true;
}
var lastBlock = block.Statements[block.Statements.Count-1] as DecompiledBlock;
if (lastBlock != null && this.RemoveEndFinallyFrom(lastBlock)) return true;
LabeledStatement endFinally = new LabeledStatement() { Label = this.host.NameTable.GetNameFor("__endfinally#"+this.endFinallyCounter++), Statement = new EmptyStatement() };
block.Statements.Add(endFinally);
return this.RemoveEndFinallyFrom(block, endFinally);
}
private void RemoveLocalDeclarationOf(ILocalDefinition exceptionContainer, DecompiledBlock block) {
Contract.Requires(exceptionContainer != null);
Contract.Requires(block != null);
this.localDeclarationRemover.localVariableToRemove = exceptionContainer;
this.localDeclarationRemover.StopTraversal = false;
this.localDeclarationRemover.Traverse(block);
}
private ILocalDefinition ExtractExceptionContainer(DecompiledBlock nestedBlock, ITypeReference exceptionType)
{
Contract.Requires(nestedBlock != null);
Contract.Requires(exceptionType != null);
Contract.Ensures(Contract.Result <ILocalDefinition>() != null);
Contract.Assume(nestedBlock.Statements.Count > 0);
int i = 0;
while (nestedBlock.Statements[i] is LocalDeclarationStatement)
{
i++; Contract.Assume(i < nestedBlock.Statements.Count);
}
;
var firstStatement = nestedBlock.Statements[i++];
var firstBlock = firstStatement as DecompiledBlock;
while (firstBlock != null)
{
Contract.Assume(firstBlock.Statements.Count > 0);
i = 0;
while (firstBlock.Statements[i] is LocalDeclarationStatement)
{
i++; Contract.Assume(i < firstBlock.Statements.Count);
}
;
firstStatement = firstBlock.Statements[i++];
nestedBlock = firstBlock;
firstBlock = firstStatement as DecompiledBlock;
}
//Ignoring any local declarations inserted for lexical scopes, any decompiled block that does not start with a nested block, starts with a label.
Contract.Assume(firstStatement is LabeledStatement);
if (nestedBlock.Statements.Count > i)
{
var exprStatement = nestedBlock.Statements[i] as ExpressionStatement;
if (exprStatement != null)
{
nestedBlock.Statements.RemoveRange(i - 1, 2);
if (exprStatement.Expression is PopValue)
{
return(Dummy.LocalVariable);
}
var assignment = exprStatement.Expression as Assignment;
if (assignment != null && assignment.Source is PopValue)
{
var local = assignment.Target.Definition as ILocalDefinition;
if (local != null)
{
return(local); //if not, this is not a recognized code pattern.
}
}
}
// can't find the local, so just introduce one and leave its value on the stack
var ld = new LocalDefinition()
{
Type = exceptionType,
};
var pushStatement = new PushStatement()
{
ValueToPush = new BoundExpression()
{
Definition = ld,
Type = exceptionType,
},
};
nestedBlock.Statements.Insert(0, pushStatement);
return(ld);
}
else
{
//Valid IL should always have at least one instruction to consume the exception value as well as a branch out of the handler block.
Contract.Assume(false);
return(Dummy.LocalVariable);
}
}
private void RemoveUnconditionalBranchesToLabelImmediatelyFollowing(TryCatchFinallyStatement trycf, DecompiledBlock followingBlock) {
Contract.Requires(trycf != null);
while (followingBlock != null) {
if (followingBlock.Statements.Count == 0) return;
var label = followingBlock.Statements[0] as LabeledStatement;
if (label != null) {
this.unconditionalBranchRemover.StopTraversal = false;
this.unconditionalBranchRemover.targetLabel = label;
this.unconditionalBranchRemover.Traverse(trycf);
var gotos = this.gotosThatTarget.Find((uint)label.Label.UniqueKey);
if (gotos == null || gotos.Count == 0) {
followingBlock.Statements.RemoveAt(0);
}
return;
}
followingBlock = followingBlock.Statements[0] as DecompiledBlock;
}
}
private DecompiledBlock CreateNestedBlock(DecompiledBlock block, uint startOffset, uint endOffset) {
Contract.Requires(block != null);
Contract.Requires(startOffset <= endOffset);
Contract.Ensures(Contract.Result<DecompiledBlock>() != null);
{
nextBlock:
foreach (var statement in block.Statements) {
var nestedBlock = statement as DecompiledBlock;
if (nestedBlock == null) continue;
if (nestedBlock.StartOffset <= startOffset && nestedBlock.EndOffset >= endOffset) {
block = nestedBlock;
goto nextBlock;
}
}
}
if (block.StartOffset == startOffset && block.EndOffset == endOffset) return block;
//replace block.Statements with three nested blocks, the middle one corresponding to one we have to create
//but keep any declarations.
int n = block.Statements.Count;
var oldStatements = block.Statements;
var newStatements = block.Statements;
int m = 0;
if (n >= 0) {
while (m < n && oldStatements[m] is LocalDeclarationStatement) m++;
if (m < n) {
newStatements = new List<IStatement>(m+3);
for (int i = 0; i < m; i++) newStatements.Add(oldStatements[i]);
}
}
block.Statements = newStatements;
var basicBlocks = block.GetBasicBlocksForRange(startOffset, endOffset);
var newNestedBlock = new DecompiledBlock(startOffset, endOffset, basicBlocks, isLexicalScope: true);
DecompiledBlock beforeBlock = null;
if (block.StartOffset < startOffset) {
var basicBlocksBefore = block.GetBasicBlocksForRange(block.StartOffset, startOffset);
Contract.Assume(block.StartOffset < startOffset);
beforeBlock = new DecompiledBlock(block.StartOffset, startOffset, basicBlocksBefore, isLexicalScope: false);
newStatements.Add(beforeBlock);
}
newStatements.Add(newNestedBlock);
DecompiledBlock afterBlock = null;
if (block.EndOffset > endOffset) {
var basicBlocksAfter = block.GetBasicBlocksForRange(endOffset, block.EndOffset);
Contract.Assume(block.EndOffset > endOffset);
afterBlock = new DecompiledBlock(endOffset, block.EndOffset, basicBlocksAfter, isLexicalScope: false);
newStatements.Add(afterBlock);
}
if (newStatements != oldStatements) {
//In this case there were already some nested blocks, which happens when there are nested exception blocks
//and we are creating an enclosing lexical block that does not quite coincide with block.
//We now have to populate the newly created blocks with these nested blocks, splitting them if necessary.
for (int i = m; i < n; i++) {
var nb = oldStatements[i] as DecompiledBlock;
Contract.Assume(nb != null);
if (nb.EndOffset <= startOffset) {
Contract.Assume(beforeBlock != null);
beforeBlock.Statements.Add(nb);
} else if (nb.StartOffset < startOffset) {
Contract.Assume(nb.EndOffset <= endOffset); //nb starts before newNestedBlock but ends inside it.
Contract.Assume(beforeBlock != null);
if (nb.IsLexicalScope) {
//Lexical scopes are assumed to nest cleanly. But the C# is not playing along when one using statement immediately follows another
//Well fix matters by making nb.EndOffset == startOffset
nb.EndOffset = startOffset;
beforeBlock.Statements.Add(nb);
} else
this.SplitBlock(nb, startOffset, beforeBlock.Statements, newNestedBlock.Statements);
} else if (nb.EndOffset <= endOffset) {
newNestedBlock.Statements.Add(nb);
} else if (nb.StartOffset < endOffset) {
Contract.Assert(nb.EndOffset > endOffset); //nb starts inside newNestedBlock but ends after it.
Contract.Assume(!nb.IsLexicalScope); //lexical scopes are assumed to nest cleanly.
Contract.Assume(afterBlock != null);
this.SplitBlock(nb, endOffset, newNestedBlock.Statements, afterBlock.Statements);
} else {
Contract.Assume(afterBlock != null);
afterBlock.Statements.Add(nb);
}
}
//consolidate blocks consisting of a single block
Consolidate(beforeBlock);
Consolidate(newNestedBlock);
Consolidate(afterBlock);
}
return newNestedBlock;
}
private static void ConsolidateScopes(DecompiledBlock cb) {
Contract.Requires(cb != null);
for (int i = 0; i < cb.Statements.Count; i++) {
var nb = cb.Statements[i] as DecompiledBlock;
if (nb == null) break;
if (nb.Statements.Count == 0) cb.Statements.RemoveAt(i--);
}
if (cb.Statements.Count == 1) {
var nb = cb.Statements[0] as DecompiledBlock;
if (nb != null) cb.Statements = nb.Statements;
}
}
private void RemoveRedundantFinalReturn(DecompiledBlock block) {
Contract.Requires(block != null);
var n = block.Statements.Count;
if (n > 0) {
var returnStatement = block.Statements[n-1] as ReturnStatement;
if (returnStatement == null) return;
if (this.ilMethodBody.MethodDefinition.Type.TypeCode != PrimitiveTypeCode.Void) {
var boundExpression = returnStatement.Expression as IBoundExpression;
if (boundExpression == null) return;
var local = boundExpression.Definition as ILocalDefinition;
if (local == null) return;
if (this.numberOfAssignmentsToLocal[local] > 0) return;
this.numberOfReferencesToLocal[local]--;
if (this.numberOfReferencesToLocal[local] == 0 && this.numberOfAssignmentsToLocal[local] == 0) {
for (int j = 0; j < n-1; j++) {
var locDecl = block.Statements[j] as ILocalDeclarationStatement;
if (locDecl != null && locDecl.LocalVariable == local) {
block.Statements.RemoveAt(j);
n--;
break;
}
}
}
}
block.Statements.RemoveAt(n-1);
}
}
