1 //===- CompileOnDemandLayer.h - Compile each function on demand -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // JIT layer for breaking up modules and inserting callbacks to allow
11 // individual functions to be compiled on demand.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_EXECUTIONENGINE_ORC_COMPILEONDEMANDLAYER_H
16 #define LLVM_EXECUTIONENGINE_ORC_COMPILEONDEMANDLAYER_H
18 #include "IndirectionUtils.h"
19 #include "LookasideRTDyldMM.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ExecutionEngine/SectionMemoryManager.h"
27 /// @brief Compile-on-demand layer.
29 /// Modules added to this layer have their calls indirected, and are then
30 /// broken up into a set of single-function modules, each of which is added
31 /// to the layer below in a singleton set. The lower layer can be any layer that
32 /// accepts IR module sets.
34 /// It is expected that this layer will frequently be used on top of a
35 /// LazyEmittingLayer. The combination of the two ensures that each function is
36 /// compiled only when it is first called.
37 template <typename BaseLayerT, typename CompileCallbackMgrT>
38 class CompileOnDemandLayer {
40 /// @brief Lookup helper that provides compatibility with the classic
41 /// static-compilation symbol resolution process.
43 /// The CompileOnDemand (COD) layer splits modules up into multiple
44 /// sub-modules, each held in its own llvm::Module instance, in order to
45 /// support lazy compilation. When a module that contains private symbols is
46 /// broken up symbol linkage changes may be required to enable access to
47 /// "private" data that now resides in a different llvm::Module instance. To
48 /// retain expected symbol resolution behavior for clients of the COD layer,
49 /// the CODScopedLookup class uses a two-tiered lookup system to resolve
50 /// symbols. Lookup first scans sibling modules that were split from the same
51 /// original module (logical-module scoped lookup), then scans all other
52 /// modules that have been added to the lookup scope (logical-dylib scoped
54 class CODScopedLookup {
56 typedef typename BaseLayerT::ModuleSetHandleT BaseLayerModuleSetHandleT;
57 typedef std::vector<BaseLayerModuleSetHandleT> SiblingHandlesList;
58 typedef std::list<SiblingHandlesList> PseudoDylibModuleSetHandlesList;
61 /// @brief Handle for a logical module.
62 typedef typename PseudoDylibModuleSetHandlesList::iterator LMHandle;
64 /// @brief Construct a scoped lookup.
65 CODScopedLookup(BaseLayerT &BaseLayer) : BaseLayer(BaseLayer) {}
67 /// @brief Start a new context for a single logical module.
68 LMHandle createLogicalModule() {
69 Handles.push_back(SiblingHandlesList());
70 return std::prev(Handles.end());
73 /// @brief Add a concrete Module's handle to the given logical Module's
75 void addToLogicalModule(LMHandle LMH, BaseLayerModuleSetHandleT H) {
79 /// @brief Remove a logical Module from the CODScopedLookup entirely.
80 void removeLogicalModule(LMHandle LMH) { Handles.erase(LMH); }
82 /// @brief Look up a symbol in this context.
83 JITSymbol findSymbol(LMHandle LMH, const std::string &Name) {
84 if (auto Symbol = findSymbolIn(LMH, Name))
87 for (auto I = Handles.begin(), E = Handles.end(); I != E; ++I)
89 if (auto Symbol = findSymbolIn(I, Name))
97 JITSymbol findSymbolIn(LMHandle LMH, const std::string &Name) {
99 if (auto Symbol = BaseLayer.findSymbolIn(H, Name, false))
104 BaseLayerT &BaseLayer;
105 PseudoDylibModuleSetHandlesList Handles;
109 typedef typename BaseLayerT::ModuleSetHandleT BaseLayerModuleSetHandleT;
110 typedef std::vector<BaseLayerModuleSetHandleT> BaseLayerModuleSetHandleListT;
112 struct ModuleSetInfo {
113 // Symbol lookup - just one for the whole module set.
114 std::shared_ptr<CODScopedLookup> Lookup;
116 // Logical module handles.
117 std::vector<typename CODScopedLookup::LMHandle> LMHandles;
119 // List of vectors of module set handles:
120 // One vector per logical module - each vector holds the handles for the
121 // exploded modules for that logical module in the base layer.
122 BaseLayerModuleSetHandleListT BaseLayerModuleSetHandles;
124 ModuleSetInfo(std::shared_ptr<CODScopedLookup> Lookup)
125 : Lookup(std::move(Lookup)) {}
127 void releaseResources(BaseLayerT &BaseLayer) {
128 for (auto LMH : LMHandles)
129 Lookup->removeLogicalModule(LMH);
130 for (auto H : BaseLayerModuleSetHandles)
131 BaseLayer.removeModuleSet(H);
135 typedef std::list<ModuleSetInfo> ModuleSetInfoListT;
138 /// @brief Handle to a set of loaded modules.
139 typedef typename ModuleSetInfoListT::iterator ModuleSetHandleT;
141 // @brief Fallback lookup functor.
142 typedef std::function<uint64_t(const std::string &)> LookupFtor;
144 /// @brief Construct a compile-on-demand layer instance.
145 CompileOnDemandLayer(BaseLayerT &BaseLayer, LLVMContext &Context)
146 : BaseLayer(BaseLayer),
147 CompileCallbackMgr(BaseLayer, Context, 0, 64) {}
149 /// @brief Add a module to the compile-on-demand layer.
150 template <typename ModuleSetT>
151 ModuleSetHandleT addModuleSet(ModuleSetT Ms,
152 LookupFtor FallbackLookup = nullptr) {
154 // If the user didn't supply a fallback lookup then just use
157 FallbackLookup = [=](const std::string &Name) {
158 return findSymbol(Name, true).getAddress();
161 // Create a lookup context and ModuleSetInfo for this module set.
162 // For the purposes of symbol resolution the set Ms will be treated as if
163 // the modules it contained had been linked together as a dylib.
164 auto DylibLookup = std::make_shared<CODScopedLookup>(BaseLayer);
166 ModuleSetInfos.insert(ModuleSetInfos.end(), ModuleSetInfo(DylibLookup));
167 ModuleSetInfo &MSI = ModuleSetInfos.back();
169 // Process each of the modules in this module set.
171 partitionAndAdd(*M, MSI, FallbackLookup);
176 /// @brief Remove the module represented by the given handle.
178 /// This will remove all modules in the layers below that were derived from
179 /// the module represented by H.
180 void removeModuleSet(ModuleSetHandleT H) {
181 H->releaseResources(BaseLayer);
182 ModuleSetInfos.erase(H);
185 /// @brief Search for the given named symbol.
186 /// @param Name The name of the symbol to search for.
187 /// @param ExportedSymbolsOnly If true, search only for exported symbols.
188 /// @return A handle for the given named symbol, if it exists.
189 JITSymbol findSymbol(StringRef Name, bool ExportedSymbolsOnly) {
190 return BaseLayer.findSymbol(Name, ExportedSymbolsOnly);
193 /// @brief Get the address of a symbol provided by this layer, or some layer
195 JITSymbol findSymbolIn(ModuleSetHandleT H, const std::string &Name,
196 bool ExportedSymbolsOnly) {
197 BaseLayerModuleSetHandleListT &BaseLayerHandles = H->second;
198 for (auto &BH : BaseLayerHandles) {
199 if (auto Symbol = BaseLayer.findSymbolIn(BH, Name, ExportedSymbolsOnly))
207 void partitionAndAdd(Module &M, ModuleSetInfo &MSI,
208 LookupFtor FallbackLookup) {
209 const char *AddrSuffix = "$orc_addr";
210 const char *BodySuffix = "$orc_body";
212 // We're going to break M up into a bunch of sub-modules, but we want
213 // internal linkage symbols to still resolve sensibly. CODScopedLookup
214 // provides the "logical module" concept to make this work, so create a
215 // new logical module for M.
216 auto DylibLookup = MSI.Lookup;
217 auto LogicalModule = DylibLookup->createLogicalModule();
218 MSI.LMHandles.push_back(LogicalModule);
220 // Partition M into a "globals and stubs" module, a "common symbols" module,
221 // and a list of single-function modules.
222 auto PartitionedModule = fullyPartition(M);
223 auto StubsModule = std::move(PartitionedModule.GlobalVars);
224 auto CommonsModule = std::move(PartitionedModule.Commons);
225 auto FunctionModules = std::move(PartitionedModule.Functions);
227 // Emit the commons stright away.
228 auto CommonHandle = addModule(std::move(CommonsModule), MSI, LogicalModule,
230 BaseLayer.emitAndFinalize(CommonHandle);
232 // Map of definition names to callback-info data structures. We'll use
233 // this to build the compile actions for the stubs below.
234 typedef std::map<std::string,
235 typename CompileCallbackMgrT::CompileCallbackInfo>
237 StubInfoMap StubInfos;
239 // Now we need to take each of the extracted Modules and add them to
240 // base layer. Each Module will be added individually to make sure they
241 // can be compiled separately, and each will get its own lookaside
242 // memory manager that will resolve within this logical module first.
243 for (auto &SubM : FunctionModules) {
245 // Keep track of the stubs we create for this module so that we can set
246 // their compile actions.
247 std::vector<typename StubInfoMap::iterator> NewStubInfos;
249 // Search for function definitions and insert stubs into the stubs
251 for (auto &F : *SubM) {
252 if (F.isDeclaration())
255 std::string Name = F.getName();
256 Function *Proto = StubsModule->getFunction(Name);
257 assert(Proto && "Failed to clone function decl into stubs module.");
259 CompileCallbackMgr.getCompileCallback(*Proto->getFunctionType());
260 GlobalVariable *FunctionBodyPointer =
261 createImplPointer(*Proto, Name + AddrSuffix,
262 CallbackInfo.getAddress());
263 makeStub(*Proto, *FunctionBodyPointer);
265 F.setName(Name + BodySuffix);
266 F.setVisibility(GlobalValue::HiddenVisibility);
268 auto KV = std::make_pair(std::move(Name), std::move(CallbackInfo));
269 NewStubInfos.push_back(StubInfos.insert(StubInfos.begin(), KV));
272 auto H = addModule(std::move(SubM), MSI, LogicalModule, FallbackLookup);
274 // Set the compile actions for this module:
275 for (auto &KVPair : NewStubInfos) {
276 std::string BodyName = Mangle(KVPair->first + BodySuffix,
278 auto &CCInfo = KVPair->second;
279 CCInfo.setCompileAction(
281 return BaseLayer.findSymbolIn(H, BodyName, false).getAddress();
287 // Ok - we've processed all the partitioned modules. Now add the
288 // stubs/globals module and set the update actions.
290 addModule(std::move(StubsModule), MSI, LogicalModule, FallbackLookup);
292 for (auto &KVPair : StubInfos) {
293 std::string AddrName = Mangle(KVPair.first + AddrSuffix,
295 auto &CCInfo = KVPair.second;
296 CCInfo.setUpdateAction(
297 CompileCallbackMgr.getLocalFPUpdater(StubsH, AddrName));
301 // Add the given Module to the base layer using a memory manager that will
302 // perform the appropriate scoped lookup (i.e. will look first with in the
303 // module from which it was extracted, then into the set to which that module
304 // belonged, and finally externally).
305 BaseLayerModuleSetHandleT addModule(
306 std::unique_ptr<Module> M,
308 typename CODScopedLookup::LMHandle LogicalModule,
309 LookupFtor FallbackLookup) {
311 // Add this module to the JIT with a memory manager that uses the
312 // DylibLookup to resolve symbols.
313 std::vector<std::unique_ptr<Module>> MSet;
314 MSet.push_back(std::move(M));
316 auto DylibLookup = MSI.Lookup;
318 createLookasideRTDyldMM<SectionMemoryManager>(
319 [=](const std::string &Name) {
320 if (auto Symbol = DylibLookup->findSymbol(LogicalModule, Name))
321 return Symbol.getAddress();
322 return FallbackLookup(Name);
324 [=](const std::string &Name) {
325 return DylibLookup->findSymbol(LogicalModule, Name).getAddress();
328 BaseLayerModuleSetHandleT H =
329 BaseLayer.addModuleSet(std::move(MSet), std::move(MM));
330 // Add this module to the logical module lookup.
331 DylibLookup->addToLogicalModule(LogicalModule, H);
332 MSI.BaseLayerModuleSetHandles.push_back(H);
337 static std::string Mangle(StringRef Name, const DataLayout &DL) {
339 std::string MangledName;
341 raw_string_ostream MangledNameStream(MangledName);
342 M.getNameWithPrefix(MangledNameStream, Name);
347 BaseLayerT &BaseLayer;
348 CompileCallbackMgrT CompileCallbackMgr;
349 ModuleSetInfoListT ModuleSetInfos;
352 } // End namespace orc.
353 } // End namespace llvm.
355 #endif // LLVM_EXECUTIONENGINE_ORC_COMPILEONDEMANDLAYER_H