1 //===-- LLVMContextImpl.cpp - Implement LLVMContextImpl -------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements the opaque LLVMContextImpl.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "LLVMContextImpl.h"
15 #include "llvm/ADT/STLExtras.h"
16 #include "llvm/IR/Attributes.h"
17 #include "llvm/IR/DiagnosticInfo.h"
18 #include "llvm/IR/Module.h"
19 #include "llvm/IR/OptBisect.h"
20 #include "llvm/Support/ManagedStatic.h"
21 #include <algorithm>
22 using namespace llvm;
23 
24 LLVMContextImpl::LLVMContextImpl(LLVMContext &C)
25   : TheTrueVal(nullptr), TheFalseVal(nullptr),
26     VoidTy(C, Type::VoidTyID),
27     LabelTy(C, Type::LabelTyID),
28     HalfTy(C, Type::HalfTyID),
29     FloatTy(C, Type::FloatTyID),
30     DoubleTy(C, Type::DoubleTyID),
31     MetadataTy(C, Type::MetadataTyID),
32     TokenTy(C, Type::TokenTyID),
33     X86_FP80Ty(C, Type::X86_FP80TyID),
34     FP128Ty(C, Type::FP128TyID),
35     PPC_FP128Ty(C, Type::PPC_FP128TyID),
36     X86_MMXTy(C, Type::X86_MMXTyID),
37     Int1Ty(C, 1),
38     Int8Ty(C, 8),
39     Int16Ty(C, 16),
40     Int32Ty(C, 32),
41     Int64Ty(C, 64),
42     Int128Ty(C, 128) {
43   InlineAsmDiagHandler = nullptr;
44   InlineAsmDiagContext = nullptr;
45   DiagnosticHandler = nullptr;
46   DiagnosticContext = nullptr;
47   RespectDiagnosticFilters = false;
48   YieldCallback = nullptr;
49   YieldOpaqueHandle = nullptr;
50   NamedStructTypesUniqueID = 0;
51 }
52 
53 LLVMContextImpl::~LLVMContextImpl() {
54   // NOTE: We need to delete the contents of OwnedModules, but Module's dtor
55   // will call LLVMContextImpl::removeModule, thus invalidating iterators into
56   // the container. Avoid iterators during this operation:
57   while (!OwnedModules.empty())
58     delete *OwnedModules.begin();
59 
60   // Drop references for MDNodes.  Do this before Values get deleted to avoid
61   // unnecessary RAUW when nodes are still unresolved.
62   for (auto *I : DistinctMDNodes)
63     I->dropAllReferences();
64 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
65   for (auto *I : CLASS##s)                                                     \
66     I->dropAllReferences();
67 #include "llvm/IR/Metadata.def"
68 
69   // Also drop references that come from the Value bridges.
70   for (auto &Pair : ValuesAsMetadata)
71     Pair.second->dropUsers();
72   for (auto &Pair : MetadataAsValues)
73     Pair.second->dropUse();
74 
75   // Destroy MDNodes.
76   for (MDNode *I : DistinctMDNodes)
77     I->deleteAsSubclass();
78 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
79   for (CLASS * I : CLASS##s)                                                   \
80     delete I;
81 #include "llvm/IR/Metadata.def"
82 
83   // Free the constants.
84   for (auto *I : ExprConstants)
85     I->dropAllReferences();
86   for (auto *I : ArrayConstants)
87     I->dropAllReferences();
88   for (auto *I : StructConstants)
89     I->dropAllReferences();
90   for (auto *I : VectorConstants)
91     I->dropAllReferences();
92   ExprConstants.freeConstants();
93   ArrayConstants.freeConstants();
94   StructConstants.freeConstants();
95   VectorConstants.freeConstants();
96   DeleteContainerSeconds(CAZConstants);
97   DeleteContainerSeconds(CPNConstants);
98   DeleteContainerSeconds(UVConstants);
99   InlineAsms.freeConstants();
100   DeleteContainerSeconds(IntConstants);
101   DeleteContainerSeconds(FPConstants);
102 
103   for (auto &CDSConstant : CDSConstants)
104     delete CDSConstant.second;
105   CDSConstants.clear();
106 
107   // Destroy attributes.
108   for (FoldingSetIterator<AttributeImpl> I = AttrsSet.begin(),
109          E = AttrsSet.end(); I != E; ) {
110     FoldingSetIterator<AttributeImpl> Elem = I++;
111     delete &*Elem;
112   }
113 
114   // Destroy attribute lists.
115   for (FoldingSetIterator<AttributeSetImpl> I = AttrsLists.begin(),
116          E = AttrsLists.end(); I != E; ) {
117     FoldingSetIterator<AttributeSetImpl> 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 
157   } while (Changed);
158 }
159 
160 void Module::dropTriviallyDeadConstantArrays() {
161   Context.pImpl->dropTriviallyDeadConstantArrays();
162 }
163 
164 namespace llvm {
165 /// \brief 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 
181 unsigned MDNodeOpsKey::calculateHash(MDNode *N, unsigned Offset) {
182   unsigned Hash = hash_combine_range(N->op_begin() + Offset, N->op_end());
183 #ifndef NDEBUG
184   {
185     SmallVector<Metadata *, 8> MDs(N->op_begin() + Offset, N->op_end());
186     unsigned RawHash = calculateHash(MDs);
187     assert(Hash == RawHash &&
188            "Expected hash of MDOperand to equal hash of Metadata*");
189   }
190 #endif
191   return Hash;
192 }
193 
194 unsigned MDNodeOpsKey::calculateHash(ArrayRef<Metadata *> Ops) {
195   return hash_combine_range(Ops.begin(), Ops.end());
196 }
197 
198 StringMapEntry<uint32_t> *LLVMContextImpl::getOrInsertBundleTag(StringRef Tag) {
199   uint32_t NewIdx = BundleTagCache.size();
200   return &*(BundleTagCache.insert(std::make_pair(Tag, NewIdx)).first);
201 }
202 
203 void LLVMContextImpl::getOperandBundleTags(SmallVectorImpl<StringRef> &Tags) const {
204   Tags.resize(BundleTagCache.size());
205   for (const auto &T : BundleTagCache)
206     Tags[T.second] = T.first();
207 }
208 
209 uint32_t LLVMContextImpl::getOperandBundleTagID(StringRef Tag) const {
210   auto I = BundleTagCache.find(Tag);
211   assert(I != BundleTagCache.end() && "Unknown tag!");
212   return I->second;
213 }
214 
215 // ConstantsContext anchors
216 void UnaryConstantExpr::anchor() { }
217 
218 void BinaryConstantExpr::anchor() { }
219 
220 void SelectConstantExpr::anchor() { }
221 
222 void ExtractElementConstantExpr::anchor() { }
223 
224 void InsertElementConstantExpr::anchor() { }
225 
226 void ShuffleVectorConstantExpr::anchor() { }
227 
228 void ExtractValueConstantExpr::anchor() { }
229 
230 void InsertValueConstantExpr::anchor() { }
231 
232 void GetElementPtrConstantExpr::anchor() { }
233 
234 void CompareConstantExpr::anchor() { }
235 
236 /// Singleton instance of the OptBisect class.
237 ///
238 /// This singleton is accessed via the LLVMContext::getOptBisect() function.  It
239 /// provides a mechanism to disable passes and individual optimizations at
240 /// compile time based on a command line option (-opt-bisect-limit) in order to
241 /// perform a bisecting search for optimization-related problems.
242 ///
243 /// Even if multiple LLVMContext objects are created, they will all return the
244 /// same instance of OptBisect in order to provide a single bisect count.  Any
245 /// code that uses the OptBisect object should be serialized when bisection is
246 /// enabled in order to enable a consistent bisect count.
247 static ManagedStatic<OptBisect> OptBisector;
248 
249 OptBisect &LLVMContextImpl::getOptBisect() {
250   return *OptBisector;
251 }
252