Jared Wyles 2ccf7ed277
[JITLink] Switch to SymbolStringPtr for Symbol names (#115796)
Use SymbolStringPtr for Symbol names in LinkGraph. This reduces string interning
on the boundary between JITLink and ORC, and allows pointer comparisons (rather
than string comparisons) between Symbol names. This should improve the
performance and readability of code that bridges between JITLink and ORC (e.g.
ObjectLinkingLayer and ObjectLinkingLayer::Plugins).

To enable use of SymbolStringPtr a std::shared_ptr<SymbolStringPool> is added to
LinkGraph and threaded through to its construction sites in LLVM and Bolt. All
LinkGraphs that are to have symbol names compared by pointer equality must point
to the same SymbolStringPool instance, which in ORC sessions should be the pool
attached to the ExecutionSession.
---------

Co-authored-by: Lang Hames <lhames@gmail.com>
2024-12-06 10:22:09 +11:00

54 lines
1.9 KiB
C++

//===--------- SectCreate.cpp - Emulate ld64's -sectcreate option ---------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/Orc/SectCreate.h"
#define DEBUG_TYPE "orc"
using namespace llvm::jitlink;
namespace llvm::orc {
void SectCreateMaterializationUnit::materialize(
std::unique_ptr<MaterializationResponsibility> R) {
auto G = std::make_unique<LinkGraph>(
"orc_sectcreate_" + SectName,
ObjLinkingLayer.getExecutionSession().getSymbolStringPool(),
ObjLinkingLayer.getExecutionSession().getTargetTriple(),
getGenericEdgeKindName);
auto &Sect = G->createSection(SectName, MP);
auto Content = G->allocateContent(
ArrayRef<char>(Data->getBuffer().data(), Data->getBuffer().size()));
auto &B = G->createContentBlock(Sect, Content, ExecutorAddr(), Alignment, 0);
for (auto &[Name, Info] : ExtraSymbols) {
auto L = Info.Flags.isStrong() ? Linkage::Strong : Linkage::Weak;
auto S = Info.Flags.isExported() ? Scope::Default : Scope::Hidden;
G->addDefinedSymbol(B, Info.Offset, *Name, 0, L, S, Info.Flags.isCallable(),
true);
}
ObjLinkingLayer.emit(std::move(R), std::move(G));
}
void SectCreateMaterializationUnit::discard(const JITDylib &JD,
const SymbolStringPtr &Name) {
ExtraSymbols.erase(Name);
}
MaterializationUnit::Interface SectCreateMaterializationUnit::getInterface(
const ExtraSymbolsMap &ExtraSymbols) {
SymbolFlagsMap SymbolFlags;
for (auto &[Name, Info] : ExtraSymbols)
SymbolFlags[Name] = Info.Flags;
return {std::move(SymbolFlags), nullptr};
}
} // End namespace llvm::orc.