108 lines
3.5 KiB
C++
108 lines
3.5 KiB
C++
//===--- BasicGOTAndStubsBuilder.h - Generic GOT/Stub creation --*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// A base for simple GOT and stub creation.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_LIB_EXECUTIONENGINE_JITLINK_BASICGOTANDSTUBSBUILDER_H
|
|
#define LLVM_LIB_EXECUTIONENGINE_JITLINK_BASICGOTANDSTUBSBUILDER_H
|
|
|
|
#include "llvm/ExecutionEngine/JITLink/JITLink.h"
|
|
|
|
#define DEBUG_TYPE "jitlink"
|
|
|
|
namespace llvm {
|
|
namespace jitlink {
|
|
|
|
template <typename BuilderImpl> class BasicGOTAndStubsBuilder {
|
|
public:
|
|
BasicGOTAndStubsBuilder(LinkGraph &G) : G(G) {}
|
|
|
|
void run() {
|
|
// We're going to be adding new blocks, but we don't want to iterate over
|
|
// the newly added ones, so just copy the existing blocks out.
|
|
std::vector<Block *> Blocks(G.blocks().begin(), G.blocks().end());
|
|
|
|
LLVM_DEBUG(dbgs() << "Creating GOT entries and stubs:\n");
|
|
|
|
for (auto *B : Blocks)
|
|
for (auto &E : B->edges())
|
|
if (impl().isGOTEdge(E)) {
|
|
LLVM_DEBUG({
|
|
dbgs() << " Updating GOT edge ";
|
|
printEdge(dbgs(), *B, E, "<target GOT>");
|
|
dbgs() << "\n";
|
|
});
|
|
impl().fixGOTEdge(E, getGOTEntrySymbol(E.getTarget()));
|
|
} else if (impl().isExternalBranchEdge(E)) {
|
|
LLVM_DEBUG({
|
|
dbgs() << " Updating external branch edge ";
|
|
printEdge(dbgs(), *B, E, "<target PC-rel>");
|
|
dbgs() << "\n";
|
|
});
|
|
impl().fixExternalBranchEdge(E, getStubSymbol(E.getTarget()));
|
|
}
|
|
}
|
|
|
|
protected:
|
|
Symbol &getGOTEntrySymbol(Symbol &Target) {
|
|
assert(Target.hasName() && "GOT edge cannot point to anonymous target");
|
|
|
|
auto GOTEntryI = GOTEntries.find(Target.getName());
|
|
|
|
// Build the entry if it doesn't exist.
|
|
if (GOTEntryI == GOTEntries.end()) {
|
|
auto &GOTEntry = impl().createGOTEntry(Target);
|
|
LLVM_DEBUG({
|
|
dbgs() << " Created GOT entry for " << Target.getName() << ": "
|
|
<< GOTEntry << "\n";
|
|
});
|
|
GOTEntryI =
|
|
GOTEntries.insert(std::make_pair(Target.getName(), &GOTEntry)).first;
|
|
}
|
|
|
|
assert(GOTEntryI != GOTEntries.end() && "Could not get GOT entry symbol");
|
|
LLVM_DEBUG(
|
|
{ dbgs() << " Using GOT entry " << *GOTEntryI->second << "\n"; });
|
|
return *GOTEntryI->second;
|
|
}
|
|
|
|
Symbol &getStubSymbol(Symbol &Target) {
|
|
assert(Target.hasName() &&
|
|
"External branch edge can not point to an anonymous target");
|
|
auto StubI = Stubs.find(Target.getName());
|
|
|
|
if (StubI == Stubs.end()) {
|
|
auto &StubSymbol = impl().createStub(Target);
|
|
LLVM_DEBUG({
|
|
dbgs() << " Created stub for " << Target.getName() << ": "
|
|
<< StubSymbol << "\n";
|
|
});
|
|
StubI = Stubs.insert(std::make_pair(Target.getName(), &StubSymbol)).first;
|
|
}
|
|
|
|
assert(StubI != Stubs.end() && "Count not get stub symbol");
|
|
LLVM_DEBUG({ dbgs() << " Using stub " << *StubI->second << "\n"; });
|
|
return *StubI->second;
|
|
}
|
|
|
|
LinkGraph &G;
|
|
|
|
private:
|
|
BuilderImpl &impl() { return static_cast<BuilderImpl &>(*this); }
|
|
|
|
DenseMap<StringRef, Symbol *> GOTEntries;
|
|
DenseMap<StringRef, Symbol *> Stubs;
|
|
};
|
|
|
|
} // end namespace jitlink
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_LIB_EXECUTIONENGINE_JITLINK_BASICGOTANDSTUBSBUILDER_H
|