llvm-project/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp

280 lines
9.6 KiB
C++

//===----- CompileOnDemandLayer.cpp - Lazily emit IR on first call --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/Module.h"
using namespace llvm;
using namespace llvm::orc;
static ThreadSafeModule extractSubModule(ThreadSafeModule &TSM,
StringRef Suffix,
GVPredicate ShouldExtract) {
auto DeleteExtractedDefs = [](GlobalValue &GV) {
// Bump the linkage: this global will be provided by the external module.
GV.setLinkage(GlobalValue::ExternalLinkage);
// Delete the definition in the source module.
if (isa<Function>(GV)) {
auto &F = cast<Function>(GV);
F.deleteBody();
F.setPersonalityFn(nullptr);
} else if (isa<GlobalVariable>(GV)) {
cast<GlobalVariable>(GV).setInitializer(nullptr);
} else if (isa<GlobalAlias>(GV)) {
// We need to turn deleted aliases into function or variable decls based
// on the type of their aliasee.
auto &A = cast<GlobalAlias>(GV);
Constant *Aliasee = A.getAliasee();
assert(A.hasName() && "Anonymous alias?");
assert(Aliasee->hasName() && "Anonymous aliasee");
std::string AliasName = A.getName();
if (isa<Function>(Aliasee)) {
auto *F = cloneFunctionDecl(*A.getParent(), *cast<Function>(Aliasee));
A.replaceAllUsesWith(F);
A.eraseFromParent();
F->setName(AliasName);
} else if (isa<GlobalVariable>(Aliasee)) {
auto *G = cloneGlobalVariableDecl(*A.getParent(),
*cast<GlobalVariable>(Aliasee));
A.replaceAllUsesWith(G);
A.eraseFromParent();
G->setName(AliasName);
} else
llvm_unreachable("Alias to unsupported type");
} else
llvm_unreachable("Unsupported global type");
};
auto NewTSMod = cloneToNewContext(TSM, ShouldExtract, DeleteExtractedDefs);
auto &M = *NewTSMod.getModule();
M.setModuleIdentifier((M.getModuleIdentifier() + Suffix).str());
return NewTSMod;
}
namespace llvm {
namespace orc {
class PartitioningIRMaterializationUnit : public IRMaterializationUnit {
public:
PartitioningIRMaterializationUnit(ExecutionSession &ES, ThreadSafeModule TSM,
CompileOnDemandLayer2 &Parent)
: IRMaterializationUnit(ES, std::move(TSM)), Parent(Parent) {}
PartitioningIRMaterializationUnit(
ThreadSafeModule TSM, SymbolFlagsMap SymbolFlags,
SymbolNameToDefinitionMap SymbolToDefinition,
CompileOnDemandLayer2 &Parent)
: IRMaterializationUnit(std::move(TSM), std::move(SymbolFlags),
std::move(SymbolToDefinition)),
Parent(Parent) {}
private:
void materialize(MaterializationResponsibility R) override {
Parent.emitPartition(std::move(R), std::move(TSM),
std::move(SymbolToDefinition));
}
void discard(const JITDylib &V, SymbolStringPtr Name) override {
// All original symbols were materialized by the CODLayer and should be
// final. The function bodies provided by M should never be overridden.
llvm_unreachable("Discard should never be called on an "
"ExtractingIRMaterializationUnit");
}
mutable std::mutex SourceModuleMutex;
CompileOnDemandLayer2 &Parent;
};
Optional<CompileOnDemandLayer2::GlobalValueSet>
CompileOnDemandLayer2::compileRequested(GlobalValueSet Requested) {
return std::move(Requested);
}
Optional<CompileOnDemandLayer2::GlobalValueSet>
CompileOnDemandLayer2::compileWholeModule(GlobalValueSet Requested) {
return None;
}
CompileOnDemandLayer2::CompileOnDemandLayer2(
ExecutionSession &ES, IRLayer &BaseLayer, LazyCallThroughManager &LCTMgr,
IndirectStubsManagerBuilder BuildIndirectStubsManager)
: IRLayer(ES), BaseLayer(BaseLayer), LCTMgr(LCTMgr),
BuildIndirectStubsManager(std::move(BuildIndirectStubsManager)) {}
void CompileOnDemandLayer2::setPartitionFunction(PartitionFunction Partition) {
this->Partition = std::move(Partition);
}
void CompileOnDemandLayer2::emit(MaterializationResponsibility R, VModuleKey K,
ThreadSafeModule TSM) {
assert(TSM.getModule() && "Null module");
auto &ES = getExecutionSession();
auto &M = *TSM.getModule();
// First, do some cleanup on the module:
cleanUpModule(M);
// Now sort the callables and non-callables, build re-exports and lodge the
// actual module with the implementation dylib.
auto &PDR = getPerDylibResources(R.getTargetJITDylib());
MangleAndInterner Mangle(ES, M.getDataLayout());
SymbolAliasMap NonCallables;
SymbolAliasMap Callables;
for (auto &GV : M.global_values()) {
assert(GV.hasName() && !GV.hasLocalLinkage() &&
"GlobalValues must have been promoted before adding to "
"CompileOnDemandLayer");
if (GV.isDeclaration() || GV.hasAppendingLinkage())
continue;
auto Name = Mangle(GV.getName());
auto Flags = JITSymbolFlags::fromGlobalValue(GV);
if (Flags.isCallable())
Callables[Name] = SymbolAliasMapEntry(Name, Flags);
else
NonCallables[Name] = SymbolAliasMapEntry(Name, Flags);
}
// Create a partitioning materialization unit and lodge it with the
// implementation dylib.
if (auto Err = PDR.getImplDylib().define(
llvm::make_unique<PartitioningIRMaterializationUnit>(
ES, std::move(TSM), *this))) {
ES.reportError(std::move(Err));
R.failMaterialization();
return;
}
R.replace(reexports(PDR.getImplDylib(), std::move(NonCallables)));
R.replace(lazyReexports(LCTMgr, PDR.getISManager(), PDR.getImplDylib(),
std::move(Callables)));
}
CompileOnDemandLayer2::PerDylibResources &
CompileOnDemandLayer2::getPerDylibResources(JITDylib &TargetD) {
auto I = DylibResources.find(&TargetD);
if (I == DylibResources.end()) {
auto &ImplD =
getExecutionSession().createJITDylib(TargetD.getName() + ".impl");
TargetD.withSearchOrderDo([&](const JITDylibList &TargetSearchOrder) {
ImplD.setSearchOrder(TargetSearchOrder, false);
});
PerDylibResources PDR(ImplD, BuildIndirectStubsManager());
I = DylibResources.insert(std::make_pair(&TargetD, std::move(PDR))).first;
}
return I->second;
}
void CompileOnDemandLayer2::cleanUpModule(Module &M) {
for (auto &F : M.functions()) {
if (F.isDeclaration())
continue;
if (F.hasAvailableExternallyLinkage()) {
F.deleteBody();
F.setPersonalityFn(nullptr);
continue;
}
}
}
void CompileOnDemandLayer2::expandPartition(GlobalValueSet &Partition) {
// Expands the partition to ensure the following rules hold:
// (1) If any alias is in the partition, its aliasee is also in the partition.
// (2) If any aliasee is in the partition, its aliases are also in the
// partiton.
// (3) If any global variable is in the partition then all global variables
// are in the partition.
assert(!Partition.empty() && "Unexpected empty partition");
const Module &M = *(*Partition.begin())->getParent();
bool ContainsGlobalVariables = false;
std::vector<const GlobalValue *> GVsToAdd;
for (auto *GV : Partition)
if (isa<GlobalAlias>(GV))
GVsToAdd.push_back(
cast<GlobalValue>(cast<GlobalAlias>(GV)->getAliasee()));
else if (isa<GlobalVariable>(GV))
ContainsGlobalVariables = true;
for (auto &A : M.aliases())
if (Partition.count(cast<GlobalValue>(A.getAliasee())))
GVsToAdd.push_back(&A);
if (ContainsGlobalVariables)
for (auto &G : M.globals())
GVsToAdd.push_back(&G);
for (auto *GV : GVsToAdd)
Partition.insert(GV);
}
void CompileOnDemandLayer2::emitPartition(
MaterializationResponsibility R, ThreadSafeModule TSM,
IRMaterializationUnit::SymbolNameToDefinitionMap Defs) {
// FIXME: Need a 'notify lazy-extracting/emitting' callback to tie the
// extracted module key, extracted module, and source module key
// together. This could be used, for example, to provide a specific
// memory manager instance to the linking layer.
auto &ES = getExecutionSession();
GlobalValueSet RequestedGVs;
for (auto &Name : R.getRequestedSymbols()) {
assert(Defs.count(Name) && "No definition for symbol");
RequestedGVs.insert(Defs[Name]);
}
auto GVsToExtract = Partition(RequestedGVs);
// Take a 'None' partition to mean the whole module (as opposed to an empty
// partition, which means "materialize nothing"). Emit the whole module
// unmodified to the base layer.
if (GVsToExtract == None) {
Defs.clear();
BaseLayer.emit(std::move(R), ES.allocateVModule(), std::move(TSM));
return;
}
// If the partition is empty, return the whole module to the symbol table.
if (GVsToExtract->empty()) {
R.replace(llvm::make_unique<PartitioningIRMaterializationUnit>(
std::move(TSM), R.getSymbols(), std::move(Defs), *this));
return;
}
expandPartition(*GVsToExtract);
// Extract the requested partiton (plus any necessary aliases) and
// put the rest back into the impl dylib.
auto ShouldExtract = [&](const GlobalValue &GV) -> bool {
return GVsToExtract->count(&GV);
};
auto ExtractedTSM = extractSubModule(TSM, ".submodule", ShouldExtract);
R.replace(llvm::make_unique<PartitioningIRMaterializationUnit>(
ES, std::move(TSM), *this));
BaseLayer.emit(std::move(R), ES.allocateVModule(), std::move(ExtractedTSM));
}
} // end namespace orc
} // end namespace llvm