llvm/lib/IR/LLVMContextImpl.cpp

   1 //===- LLVMContextImpl.cpp - Implement LLVMContextImpl --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file implements the opaque LLVMContextImpl.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "LLVMContextImpl.h"
  14 #include "llvm/IR/Module.h"
  15 #include "llvm/IR/OptBisect.h"
  16 #include "llvm/IR/Type.h"
  17 #include "llvm/Support/ManagedStatic.h"
  18 #include <cassert>
  19 #include <utility>
  20
  21 using namespace llvm;
  22
  23 LLVMContextImpl::LLVMContextImpl(LLVMContext &C)
  24   : DiagHandler(llvm::make_unique<DiagnosticHandler>()),
  25     VoidTy(C, Type::VoidTyID),
  26     LabelTy(C, Type::LabelTyID),
  27     HalfTy(C, Type::HalfTyID),
  28     FloatTy(C, Type::FloatTyID),
  29     DoubleTy(C, Type::DoubleTyID),
  30     MetadataTy(C, Type::MetadataTyID),
  31     TokenTy(C, Type::TokenTyID),
  32     X86_FP80Ty(C, Type::X86_FP80TyID),
  33     FP128Ty(C, Type::FP128TyID),
  34     PPC_FP128Ty(C, Type::PPC_FP128TyID),
  35     X86_MMXTy(C, Type::X86_MMXTyID),
  36     Int1Ty(C, 1),
  37     Int8Ty(C, 8),
  38     Int16Ty(C, 16),
  39     Int32Ty(C, 32),
  40     Int64Ty(C, 64),
  41     Int128Ty(C, 128) {}
  42
  43 LLVMContextImpl::~LLVMContextImpl() {
  44   // NOTE: We need to delete the contents of OwnedModules, but Module's dtor
  45   // will call LLVMContextImpl::removeModule, thus invalidating iterators into
  46   // the container. Avoid iterators during this operation:
  47   while (!OwnedModules.empty())
  48     delete *OwnedModules.begin();
  49
  50 #ifndef NDEBUG
  51   // Check for metadata references from leaked Instructions.
  52   for (auto &Pair : InstructionMetadata)
  53     Pair.first->dump();
  54   assert(InstructionMetadata.empty() &&
  55          "Instructions with metadata have been leaked");
  56 #endif
  57
  58   // Drop references for MDNodes.  Do this before Values get deleted to avoid
  59   // unnecessary RAUW when nodes are still unresolved.
  60   for (auto *I : DistinctMDNodes)
  61     I->dropAllReferences();
  62 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
  63   for (auto *I : CLASS##s)                                                     \
  64     I->dropAllReferences();
  65 #include "llvm/IR/Metadata.def"
  66
  67   // Also drop references that come from the Value bridges.
  68   for (auto &Pair : ValuesAsMetadata)
  69     Pair.second->dropUsers();
  70   for (auto &Pair : MetadataAsValues)
  71     Pair.second->dropUse();
  72
  73   // Destroy MDNodes.
  74   for (MDNode *I : DistinctMDNodes)
  75     I->deleteAsSubclass();
  76 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
  77   for (CLASS * I : CLASS##s)                                                   \
  78     delete I;
  79 #include "llvm/IR/Metadata.def"
  80
  81   // Free the constants.
  82   for (auto *I : ExprConstants)
  83     I->dropAllReferences();
  84   for (auto *I : ArrayConstants)
  85     I->dropAllReferences();
  86   for (auto *I : StructConstants)
  87     I->dropAllReferences();
  88   for (auto *I : VectorConstants)
  89     I->dropAllReferences();
  90   ExprConstants.freeConstants();
  91   ArrayConstants.freeConstants();
  92   StructConstants.freeConstants();
  93   VectorConstants.freeConstants();
  94   InlineAsms.freeConstants();
  95
  96   CAZConstants.clear();
  97   CPNConstants.clear();
  98   UVConstants.clear();
  99   IntConstants.clear();
 100   FPConstants.clear();
 101
 102   for (auto &CDSConstant : CDSConstants)
 103     delete CDSConstant.second;
 104   CDSConstants.clear();
 105
 106   // Destroy attributes.
 107   for (FoldingSetIterator<AttributeImpl> I = AttrsSet.begin(),
 108          E = AttrsSet.end(); I != E; ) {
 109     FoldingSetIterator<AttributeImpl> Elem = I++;
 110     delete &*Elem;
 111   }
 112
 113   // Destroy attribute lists.
 114   for (FoldingSetIterator<AttributeListImpl> I = AttrsLists.begin(),
 115                                              E = AttrsLists.end();
 116        I != E;) {
 117     FoldingSetIterator<AttributeListImpl> Elem = I++;
 118     delete &*Elem;
 119   }
 120
 121   // Destroy attribute node lists.
 122   for (FoldingSetIterator<AttributeSetNode> I = AttrsSetNodes.begin(),
 123          E = AttrsSetNodes.end(); I != E; ) {
 124     FoldingSetIterator<AttributeSetNode> Elem = I++;
 125     delete &*Elem;
 126   }
 127
 128   // Destroy MetadataAsValues.
 129   {
 130     SmallVector<MetadataAsValue *, 8> MDVs;
 131     MDVs.reserve(MetadataAsValues.size());
 132     for (auto &Pair : MetadataAsValues)
 133       MDVs.push_back(Pair.second);
 134     MetadataAsValues.clear();
 135     for (auto *V : MDVs)
 136       delete V;
 137   }
 138
 139   // Destroy ValuesAsMetadata.
 140   for (auto &Pair : ValuesAsMetadata)
 141     delete Pair.second;
 142 }
 143
 144 void LLVMContextImpl::dropTriviallyDeadConstantArrays() {
 145   bool Changed;
 146   do {
 147     Changed = false;
 148
 149     for (auto I = ArrayConstants.begin(), E = ArrayConstants.end(); I != E;) {
 150       auto *C = *I++;
 151       if (C->use_empty()) {
 152         Changed = true;
 153         C->destroyConstant();
 154       }
 155     }
 156   } while (Changed);
 157 }
 158
 159 void Module::dropTriviallyDeadConstantArrays() {
 160   Context.pImpl->dropTriviallyDeadConstantArrays();
 161 }
 162
 163 namespace llvm {
 164
 165 /// Make MDOperand transparent for hashing.
 166 ///
 167 /// This overload of an implementation detail of the hashing library makes
 168 /// MDOperand hash to the same value as a \a Metadata pointer.
 169 ///
 170 /// Note that overloading \a hash_value() as follows:
 171 ///
 172 /// \code
 173 ///     size_t hash_value(const MDOperand &X) { return hash_value(X.get()); }
 174 /// \endcode
 175 ///
 176 /// does not cause MDOperand to be transparent.  In particular, a bare pointer
 177 /// doesn't get hashed before it's combined, whereas \a MDOperand would.
 178 static const Metadata *get_hashable_data(const MDOperand &X) { return X.get(); }
 179
 180 } // end namespace llvm
 181
 182 unsigned MDNodeOpsKey::calculateHash(MDNode *N, unsigned Offset) {
 183   unsigned Hash = hash_combine_range(N->op_begin() + Offset, N->op_end());
 184 #ifndef NDEBUG
 185   {
 186     SmallVector<Metadata *, 8> MDs(N->op_begin() + Offset, N->op_end());
 187     unsigned RawHash = calculateHash(MDs);
 188     assert(Hash == RawHash &&
 189            "Expected hash of MDOperand to equal hash of Metadata*");
 190   }
 191 #endif
 192   return Hash;
 193 }
 194
 195 unsigned MDNodeOpsKey::calculateHash(ArrayRef<Metadata *> Ops) {
 196   return hash_combine_range(Ops.begin(), Ops.end());
 197 }
 198
 199 StringMapEntry<uint32_t> *LLVMContextImpl::getOrInsertBundleTag(StringRef Tag) {
 200   uint32_t NewIdx = BundleTagCache.size();
 201   return &*(BundleTagCache.insert(std::make_pair(Tag, NewIdx)).first);
 202 }
 203
 204 void LLVMContextImpl::getOperandBundleTags(SmallVectorImpl<StringRef> &Tags) const {
 205   Tags.resize(BundleTagCache.size());
 206   for (const auto &T : BundleTagCache)
 207     Tags[T.second] = T.first();
 208 }
 209
 210 uint32_t LLVMContextImpl::getOperandBundleTagID(StringRef Tag) const {
 211   auto I = BundleTagCache.find(Tag);
 212   assert(I != BundleTagCache.end() && "Unknown tag!");
 213   return I->second;
 214 }
 215
 216 SyncScope::ID LLVMContextImpl::getOrInsertSyncScopeID(StringRef SSN) {
 217   auto NewSSID = SSC.size();
 218   assert(NewSSID < std::numeric_limits<SyncScope::ID>::max() &&
 219          "Hit the maximum number of synchronization scopes allowed!");
 220   return SSC.insert(std::make_pair(SSN, SyncScope::ID(NewSSID))).first->second;
 221 }
 222
 223 void LLVMContextImpl::getSyncScopeNames(
 224     SmallVectorImpl<StringRef> &SSNs) const {
 225   SSNs.resize(SSC.size());
 226   for (const auto &SSE : SSC)
 227     SSNs[SSE.second] = SSE.first();
 228 }
 229
 230 /// Singleton instance of the OptBisect class.
 231 ///
 232 /// This singleton is accessed via the LLVMContext::getOptPassGate() function.
 233 /// It provides a mechanism to disable passes and individual optimizations at
 234 /// compile time based on a command line option (-opt-bisect-limit) in order to
 235 /// perform a bisecting search for optimization-related problems.
 236 ///
 237 /// Even if multiple LLVMContext objects are created, they will all return the
 238 /// same instance of OptBisect in order to provide a single bisect count.  Any
 239 /// code that uses the OptBisect object should be serialized when bisection is
 240 /// enabled in order to enable a consistent bisect count.
 241 static ManagedStatic<OptBisect> OptBisector;
 242
 243 OptPassGate &LLVMContextImpl::getOptPassGate() const {
 244   if (!OPG)
 245     OPG = &(*OptBisector);
 246   return *OPG;
 247 }
 248
 249 void LLVMContextImpl::setOptPassGate(OptPassGate& OPG) {
 250   this->OPG = &OPG;
 251 }