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#include "llvm/ADT/Triple.h"
#include "llvm/ExecutionEngine/Orc/IndirectionUtils.h"
#include "llvm/ExecutionEngine/Orc/CloneSubModule.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/IRBuilder.h"
#include <set>
using namespace llvm;
namespace llvm {
JITIndirections makeCallsSingleIndirect(
Module &M, const std::function<bool(const Function &)> &ShouldIndirect,
const char *JITImplSuffix, const char *JITAddrSuffix) {
std::vector<Function *> Worklist;
std::vector<std::string> FuncNames;
for (auto &F : M)
if (ShouldIndirect(F) && (F.user_begin() != F.user_end())) {
Worklist.push_back(&F);
FuncNames.push_back(F.getName());
}
for (auto *F : Worklist) {
GlobalVariable *FImplAddr = new GlobalVariable(
M, F->getType(), false, GlobalValue::ExternalLinkage,
Constant::getNullValue(F->getType()), F->getName() + JITAddrSuffix,
nullptr, GlobalValue::NotThreadLocal, 0, true);
FImplAddr->setVisibility(GlobalValue::HiddenVisibility);
for (auto *U : F->users()) {
assert(isa<Instruction>(U) && "Cannot indirect non-instruction use");
IRBuilder<> Builder(cast<Instruction>(U));
U->replaceUsesOfWith(F, Builder.CreateLoad(FImplAddr));
}
}
return JITIndirections(
FuncNames, [=](StringRef S) -> std::string { return std::string(S); },
[=](StringRef S)
-> std::string { return std::string(S) + JITAddrSuffix; });
}
JITIndirections makeCallsDoubleIndirect(
Module &M, const std::function<bool(const Function &)> &ShouldIndirect,
const char *JITImplSuffix, const char *JITAddrSuffix) {
std::vector<Function *> Worklist;
std::vector<std::string> FuncNames;
for (auto &F : M)
if (!F.isDeclaration() && !F.hasAvailableExternallyLinkage() &&
ShouldIndirect(F))
Worklist.push_back(&F);
for (auto *F : Worklist) {
std::string OrigName = F->getName();
F->setName(OrigName + JITImplSuffix);
FuncNames.push_back(OrigName);
GlobalVariable *FImplAddr = new GlobalVariable(
M, F->getType(), false, GlobalValue::ExternalLinkage,
Constant::getNullValue(F->getType()), OrigName + JITAddrSuffix, nullptr,
GlobalValue::NotThreadLocal, 0, true);
FImplAddr->setVisibility(GlobalValue::HiddenVisibility);
Function *FRedirect =
Function::Create(F->getFunctionType(), F->getLinkage(), OrigName, &M);
F->replaceAllUsesWith(FRedirect);
BasicBlock *EntryBlock =
BasicBlock::Create(M.getContext(), "entry", FRedirect);
IRBuilder<> Builder(EntryBlock);
LoadInst *FImplLoadedAddr = Builder.CreateLoad(FImplAddr);
std::vector<Value *> CallArgs;
for (Value &Arg : FRedirect->args())
CallArgs.push_back(&Arg);
CallInst *Call = Builder.CreateCall(FImplLoadedAddr, CallArgs);
Call->setTailCall();
Builder.CreateRet(Call);
}
return JITIndirections(
FuncNames, [=](StringRef S)
-> std::string { return std::string(S) + JITImplSuffix; },
[=](StringRef S)
-> std::string { return std::string(S) + JITAddrSuffix; });
}
std::vector<std::unique_ptr<Module>>
explode(const Module &OrigMod,
const std::function<bool(const Function &)> &ShouldExtract) {
std::vector<std::unique_ptr<Module>> NewModules;
// Split all the globals, non-indirected functions, etc. into a single module.
auto ExtractGlobalVars = [&](GlobalVariable &New, const GlobalVariable &Orig,
ValueToValueMapTy &VMap) {
copyGVInitializer(New, Orig, VMap);
if (New.getLinkage() == GlobalValue::PrivateLinkage) {
New.setLinkage(GlobalValue::ExternalLinkage);
New.setVisibility(GlobalValue::HiddenVisibility);
}
};
auto ExtractNonImplFunctions =
[&](Function &New, const Function &Orig, ValueToValueMapTy &VMap) {
if (!ShouldExtract(New))
copyFunctionBody(New, Orig, VMap);
};
NewModules.push_back(CloneSubModule(OrigMod, ExtractGlobalVars,
ExtractNonImplFunctions, true));
// Preserve initializers for Common linkage vars, and make private linkage
// globals external: they are now provided by the globals module extracted
// above.
auto DropGlobalVars = [&](GlobalVariable &New, const GlobalVariable &Orig,
ValueToValueMapTy &VMap) {
if (New.getLinkage() == GlobalValue::CommonLinkage)
copyGVInitializer(New, Orig, VMap);
else if (New.getLinkage() == GlobalValue::PrivateLinkage)
New.setLinkage(GlobalValue::ExternalLinkage);
};
// Split each 'impl' function out in to its own module.
for (const auto &Func : OrigMod) {
if (Func.isDeclaration() || !ShouldExtract(Func))
continue;
auto ExtractNamedFunction =
[&](Function &New, const Function &Orig, ValueToValueMapTy &VMap) {
if (New.getName() == Func.getName())
copyFunctionBody(New, Orig, VMap);
};
NewModules.push_back(
CloneSubModule(OrigMod, DropGlobalVars, ExtractNamedFunction, false));
}
return NewModules;
}
std::vector<std::unique_ptr<Module>>
explode(const Module &OrigMod, const JITIndirections &Indirections) {
std::set<std::string> ImplNames;
for (const auto &FuncName : Indirections.IndirectedNames)
ImplNames.insert(Indirections.GetImplName(FuncName));
return explode(
OrigMod, [&](const Function &F) { return ImplNames.count(F.getName()); });
}
}
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