private void RunCore(
ControlFlowGraph cfg,
SortedSet <int> worklist,
SortedSet <int> pendingBlocksNeedingAtLeastOnePass,
TAnalysisData initialAnalysisDataOpt,
DataFlowAnalysisResultBuilder <TAnalysisData> resultBuilder,
PooledHashSet <BasicBlock> uniqueSuccessors,
PooledDictionary <int, List <BranchWithInfo> > finallyBlockSuccessorsMap,
PooledDictionary <ControlFlowRegion, TAnalysisData> catchBlockInputDataMap,
PooledDictionary <int, TAnalysisData> inputDataFromInfeasibleBranchesMap,
PooledDictionary <int, (int Ordinal, ControlFlowConditionKind BranchKind)?> blockToUniqueInputFlowMap,
private TAnalysisResult Run(TAnalysisContext analysisContext)
{
var cfg = analysisContext.ControlFlowGraph;
var resultBuilder = new DataFlowAnalysisResultBuilder <TAnalysisData>();
var uniqueSuccessors = PooledHashSet <BasicBlock> .GetInstance();
var finallyBlockSuccessorsMap = PooledDictionary <int, List <BranchWithInfo> > .GetInstance();
var catchBlockInputDataMap = PooledDictionary <ControlFlowRegion, TAnalysisData> .GetInstance();
var inputDataFromInfeasibleBranchesMap = PooledDictionary <int, TAnalysisData> .GetInstance();
var unreachableBlocks = PooledHashSet <int> .GetInstance();
var worklist = new SortedSet <int>();
var pendingBlocksNeedingAtLeastOnePass = new SortedSet <int>(cfg.Blocks.Select(b => b.Ordinal));
// Map from Ordinal -> (Ordinal, ControlFlowConditionKind)? with following semantics:
// 1. Key is a valid basic block ordinal.
// 2. Value tuple indicates the following:
// a. Non-null tuple value: Indicates a unique branch entering the block, with following tuple values:
// i. Ordinal of the single unique block from which analysis data has been transferred into the Key,
// which is normally a predecessor but can be a non-predecessor block for finally/catch.
// ii. ControlFlowConditionKind indicating the nature of branch, i.e. conditional or fall through.
// This is required as CFG can have both conditional and fall through branches
// with the same source and destination blocks.
// b. Null tuple value: Block had analysis data flowing into it from multiple different branches.
//
// This map allows us to optimize the number of merge operations. We can avoid merge and directly
// overwrite analysis data into a successor if successor block has no entry or entry with non-null tuple value
// with the matching input branch.
var blockToUniqueInputFlowMap = PooledDictionary <int, (int Ordinal, ControlFlowConditionKind BranchKind)?> .GetInstance();
// Map from basic block ordinals that are destination of back edge(s) to the minimum block ordinal that dominates it,
// i.e. for every '{key, value}' pair in the dictionary, 'key' is the destination of at least one back edge
// and 'value' is the minimum ordinal such that there is no back edge to 'key' from any basic block with ordinal > 'value'.
var loopRangeMap = PooledDictionary <int, int> .GetInstance();
ComputeLoopRangeMap(cfg, loopRangeMap);
TAnalysisData normalPathsExitBlockData = null, exceptionPathsExitBlockDataOpt = null;
try
{
// Add each basic block to the result.
foreach (var block in cfg.Blocks)
{
resultBuilder.Add(block);
}
var entry = cfg.GetEntry();
// Initialize the input of the entry block.
// For context sensitive inter-procedural analysis, use the provided initial analysis data.
// Otherwise, initialize with the default bottom value of the analysis domain.
var initialAnalysisDataOpt = analysisContext.InterproceduralAnalysisDataOpt?.InitialAnalysisData;
UpdateInput(resultBuilder, entry, GetClonedAnalysisDataOrEmptyData(initialAnalysisDataOpt));
// Add the block to the worklist.
worklist.Add(entry.Ordinal);
RunCore(cfg, worklist, pendingBlocksNeedingAtLeastOnePass, initialAnalysisDataOpt, resultBuilder,
uniqueSuccessors, finallyBlockSuccessorsMap, catchBlockInputDataMap, inputDataFromInfeasibleBranchesMap,
blockToUniqueInputFlowMap, loopRangeMap, exceptionPathsAnalysisPostPass: false);
normalPathsExitBlockData = resultBuilder.ExitBlockOutputData;
if (analysisContext.ExceptionPathsAnalysis)
{
// Clone and save exit block data
normalPathsExitBlockData = AnalysisDomain.Clone(normalPathsExitBlockData);
OperationVisitor.ExecutingExceptionPathsAnalysisPostPass = true;
foreach (var block in cfg.Blocks)
{
blockToUniqueInputFlowMap[block.Ordinal] = null;
// Skip entry block analysis.
if (block.Kind == BasicBlockKind.Entry)
{
continue;
}
if (block.IsReachable)
{
worklist.Add(block.Ordinal);
}
else
{
pendingBlocksNeedingAtLeastOnePass.Add(block.Ordinal);
}
}
RunCore(cfg, worklist, pendingBlocksNeedingAtLeastOnePass, initialAnalysisDataOpt, resultBuilder, uniqueSuccessors,
finallyBlockSuccessorsMap, catchBlockInputDataMap, inputDataFromInfeasibleBranchesMap,
blockToUniqueInputFlowMap, loopRangeMap, exceptionPathsAnalysisPostPass: true);
exceptionPathsExitBlockDataOpt = resultBuilder.ExitBlockOutputData;
OperationVisitor.ExecutingExceptionPathsAnalysisPostPass = false;
}
var mergedDataForUnhandledThrowOperationsOpt = OperationVisitor.GetMergedDataForUnhandledThrowOperations();
var dataflowAnalysisResult = resultBuilder.ToResult(ToBlockResult, OperationVisitor.GetStateMap(),
OperationVisitor.GetPredicateValueKindMap(), OperationVisitor.GetReturnValueAndPredicateKind(), OperationVisitor.InterproceduralResultsMap,
resultBuilder.EntryBlockOutputData, normalPathsExitBlockData, exceptionPathsExitBlockDataOpt,
mergedDataForUnhandledThrowOperationsOpt, OperationVisitor.AnalysisDataForUnhandledThrowOperations, cfg, OperationVisitor.ValueDomain.UnknownOrMayBeValue);
return(ToResult(analysisContext, dataflowAnalysisResult));
}
finally
{
resultBuilder.Dispose();
uniqueSuccessors.Free();
finallyBlockSuccessorsMap.Free();
catchBlockInputDataMap.Values.Dispose();
catchBlockInputDataMap.Free();
inputDataFromInfeasibleBranchesMap.Values.Dispose();
inputDataFromInfeasibleBranchesMap.Free();
unreachableBlocks.Free();
blockToUniqueInputFlowMap.Free();
loopRangeMap.Free();
}
}