lib/IR/PassManager.cpp

//===- PassManager.cpp - Infrastructure for managing & running IR passes --===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/IR/PassManager.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/IR/LLVMContext.h"

using namespace llvm;

// Explicit template instantiations and specialization defininitions for core
// template typedefs.
namespace llvm {
template class AllAnalysesOn<Module>;
template class AllAnalysesOn<Function>;
template class PassManager<Module>;
template class PassManager<Function>;
template class AnalysisManager<Module>;
template class AnalysisManager<Function>;
template class InnerAnalysisManagerProxy<FunctionAnalysisManager, Module>;
template class OuterAnalysisManagerProxy<ModuleAnalysisManager, Function>;

template <>
bool FunctionAnalysisManagerModuleProxy::Result::invalidate(
    Module &M, const PreservedAnalyses &PA,
    ModuleAnalysisManager::Invalidator &Inv) {
  // If literally everything is preserved, we're done.
  if (PA.areAllPreserved())
    return false; // This is still a valid proxy.

  // If this proxy isn't marked as preserved, then even if the result remains
  // valid, the key itself may no longer be valid, so we clear everything.
  //
  // Note that in order to preserve this proxy, a module pass must ensure that
  // the FAM has been completely updated to handle the deletion of functions.
  // Specifically, any FAM-cached results for those functions need to have been
  // forcibly cleared. When preserved, this proxy will only invalidate results
  // cached on functions *still in the module* at the end of the module pass.
  auto PAC = PA.getChecker<FunctionAnalysisManagerModuleProxy>();
  if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Module>>()) {
    InnerAM->clear();
    return true;
  }

  // Directly check if the relevant set is preserved.
  bool AreFunctionAnalysesPreserved =
      PA.allAnalysesInSetPreserved<AllAnalysesOn<Function>>();

  // Now walk all the functions to see if any inner analysis invalidation is
  // necessary.
  for (Function &F : M) {
    Optional<PreservedAnalyses> FunctionPA;

    // Check to see whether the preserved set needs to be pruned based on
    // module-level analysis invalidation that triggers deferred invalidation
    // registered with the outer analysis manager proxy for this function.
    if (auto *OuterProxy =
            InnerAM->getCachedResult<ModuleAnalysisManagerFunctionProxy>(F))
      for (const auto &OuterInvalidationPair :
           OuterProxy->getOuterInvalidations()) {
        AnalysisKey *OuterAnalysisID = OuterInvalidationPair.first;
        const auto &InnerAnalysisIDs = OuterInvalidationPair.second;
        if (Inv.invalidate(OuterAnalysisID, M, PA)) {
          if (!FunctionPA)
            FunctionPA = PA;
          for (AnalysisKey *InnerAnalysisID : InnerAnalysisIDs)
            FunctionPA->abandon(InnerAnalysisID);
        }
      }

    // Check if we needed a custom PA set, and if so we'll need to run the
    // inner invalidation.
    if (FunctionPA) {
      InnerAM->invalidate(F, *FunctionPA);
      continue;
    }

    // Otherwise we only need to do invalidation if the original PA set didn't
    // preserve all function analyses.
    if (!AreFunctionAnalysesPreserved)
      InnerAM->invalidate(F, PA);
  }

  // Return false to indicate that this result is still a valid proxy.
  return false;
}
}

AnalysisSetKey CFGAnalyses::SetKey;

AnalysisSetKey PreservedAnalyses::AllAnalysesKey;