public ILBlock Build(SortedList <int, Instruction> code, bool optimize, GMContext context) // List<string> StringList, List<string> InstanceList = null) //DecompilerContext context)
{
if (code.Count == 0)
{
return(new ILBlock());
}
this.context = context;
_method = code;
this.optimize = optimize;
List <ILNode> ast = BuildPreAst();
ILBlock method = new ILBlock();
method.Body = ast;
if (context.Debug)
{
method.DebugSave("raw_body.txt");
}
betteribttest.Dissasembler.Optimize.RemoveRedundantCode(method);
foreach (var block in method.GetSelfAndChildrenRecursive <ILBlock>())
{
Optimize.SplitToBasicBlocks(block);
}
if (context.Debug)
{
method.DebugSave("basic_blocks.txt");
}
new BuildFullAst(method, context).ProcessAllExpressions(method);
if (context.Debug)
{
method.DebugSave("basic_blocks2.txt");
}
foreach (ILBlock block in method.GetSelfAndChildrenRecursive <ILBlock>())
{
bool modified;
do
{
modified = false;
modified |= block.RunOptimization(new SimpleControlFlow(method, context).PushEnviromentFix);
modified |= block.RunOptimization(new SimpleControlFlow(method, context).SimplifyShortCircuit);
modified |= block.RunOptimization(new SimpleControlFlow(method, context).SimplifyTernaryOperator);
modified |= block.RunOptimization(new SimpleControlFlow(method, context).JoinBasicBlocks);
modified |= block.RunOptimization(Optimize.SimplifyLogicNot);
} while (modified);
}
if (context.Debug)
{
method.DebugSave("before_loop.txt");
}
foreach (ILBlock block in method.GetSelfAndChildrenRecursive <ILBlock>())
{
new LoopsAndConditions().FindLoops(block);
}
if (context.Debug)
{
method.DebugSave("before_conditions.txt");
}
foreach (ILBlock block in method.GetSelfAndChildrenRecursive <ILBlock>())
{
new LoopsAndConditions().FindConditions(block);
}
FlattenBasicBlocks(method);
if (context.Debug)
{
method.DebugSave("before_gotos.txt");
}
Optimize.RemoveRedundantCode(method);
new GotoRemoval().RemoveGotos(method);
Optimize.RemoveRedundantCode(method);
new GotoRemoval().RemoveGotos(method);
GotoRemoval.RemoveRedundantCode(method);
new GotoRemoval().RemoveGotos(method);
if (context.Debug)
{
method.DebugSave("final.cpp");
}
return(method);
}
public static void RemoveRedundantCode(ILBlock method)
{
// Remove dead lables and nops and any popzs left
HashSet <ILLabel> liveLabels = new HashSet <ILLabel>(method.GetSelfAndChildrenRecursive <ILExpression>(e => e.IsBranch()).SelectMany(e => e.GetBranchTargets()));
foreach (ILBlock block in method.GetSelfAndChildrenRecursive <ILBlock>())
{
block.Body = block.Body.Where(n => !n.Match(GMCode.BadOp) && !n.Match(GMCode.Popz) && !(n is ILLabel && !liveLabels.Contains((ILLabel)n))).ToList();
}
// Remove redundant continue
foreach (ILWhileLoop loop in method.GetSelfAndChildrenRecursive <ILWhileLoop>())
{
var body = loop.BodyBlock.Body;
if (body.Count > 0 && body.Last().Match(GMCode.LoopContinue))
{
body.RemoveAt(body.Count - 1);
}
}
// Remove redundant continue
foreach (ILWithStatement with in method.GetSelfAndChildrenRecursive <ILWithStatement>())
{
var body = with.Body.Body;
if (body.Count > 0 && body.Last().Match(GMCode.LoopContinue))
{
body.RemoveAt(body.Count - 1);
}
}
// Remove redundant break at the end of case
// Remove redundant case blocks altogether
foreach (ILSwitch ilSwitch in method.GetSelfAndChildrenRecursive <ILSwitch>())
{
foreach (ILBlock ilCase in ilSwitch.CaseBlocks)
{
Debug.Assert(ilCase.EntryGoto == null);
int count = ilCase.Body.Count;
if (count >= 2)
{
if (ilCase.Body[count - 2].IsUnconditionalControlFlow() &&
ilCase.Body[count - 1].Match(GMCode.LoopOrSwitchBreak))
{
ilCase.Body.RemoveAt(count - 1);
}
}
}
// fix case block
var defaultCase = ilSwitch.CaseBlocks.SingleOrDefault(cb => cb.Values == null);
// If there is no default block, remove empty case blocks
if (defaultCase == null || (defaultCase.Body.Count == 1 && defaultCase.Body.Single().Match(GMCode.LoopOrSwitchBreak)))
{
ilSwitch.CaseBlocks.RemoveAll(b => b.Body.Count == 1 && b.Body.Single().Match(GMCode.LoopOrSwitchBreak));
}
}
// Remove redundant return at the end of method
if (method.Body.Count > 0 && (method.Body.Last().Match(GMCode.Ret) || method.Body.Last().Match(GMCode.Exit)) && ((ILExpression)method.Body.Last()).Arguments.Count == 0)
{
method.Body.RemoveAt(method.Body.Count - 1);
}
// Remove unreachable return statements
bool modified = false;
foreach (ILBlock block in method.GetSelfAndChildrenRecursive <ILBlock>())
{
for (int i = 0; i < block.Body.Count - 1;)
{
if (block.Body[i].IsUnconditionalControlFlow() && (block.Body[i + 1].Match(GMCode.Ret) || block.Body[i + 1].Match(GMCode.Exit)))
{
modified = true;
block.Body.RemoveAt(i + 1);
}
else
{
i++;
}
}
}
// Remove empty falseBlocks
foreach (ILCondition condition in method.GetSelfAndChildrenRecursive <ILCondition>().Where(x => x.FalseBlock != null && x.FalseBlock.Body.Count == 0))
{
condition.FalseBlock = null;
modified = true;
}
if (modified)
{
// More removals might be possible
new GotoRemoval().RemoveGotos(method);
}
}
