Files
clang-p2996/llvm/lib/ExecutionEngine/Orc/DebuggerSupportPlugin.cpp
Lang Hames 8b1771bd9f [ORC] Move most ORC APIs to ExecutorAddr, introduce ExecutorSymbolDef.
ExecutorAddr was introduced in b8e5f91816 as an eventual replacement for
JITTargetAddress. ExecutorSymbolDef is introduced in this patch as a
replacement for JITEvaluatedSymbol: ExecutorSymbolDef is an (ExecutorAddr,
JITSymbolFlags) pair, where JITEvaluatedSymbol was a (JITTargetAddress,
JITSymbolFlags) pair.

A number of APIs had already migrated from JITTargetAddress to ExecutorAddr,
but many of ORC's internals were still using the older type. This patch aims
to address that.

Some public APIs are affected as well. If you need to migrate your APIs you can
use the following operations:

* ExecutorAddr::toPtr replaces jitTargetAddressToPointer and
  jitTargetAddressToFunction.

* ExecutorAddr::fromPtr replace pointerToJITTargetAddress.

* ExecutorAddr(JITTargetAddress) creates an ExecutorAddr value from a
  JITTargetAddress.

* ExecutorAddr::getValue() creates a JITTargetAddress value from an
  ExecutorAddr.

JITTargetAddress and JITEvaluatedSymbol will remain in JITSymbol.h for now, but
the aim will be to eventually deprecate and remove these types (probably when
MCJIT and RuntimeDyld are deprecated).
2023-03-27 17:37:58 -07:00

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16 KiB
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//===------- DebuggerSupportPlugin.cpp - Utils for debugger support -------===//
//
// 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/DebuggerSupportPlugin.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/BinaryFormat/MachO.h"
#define DEBUG_TYPE "orc"
using namespace llvm;
using namespace llvm::jitlink;
using namespace llvm::orc;
static const char *SynthDebugSectionName = "__jitlink_synth_debug_object";
namespace {
struct MachO64LE {
using UIntPtr = uint64_t;
using Header = MachO::mach_header_64;
using SegmentLC = MachO::segment_command_64;
using Section = MachO::section_64;
using NList = MachO::nlist_64;
static constexpr support::endianness Endianness = support::little;
static constexpr const uint32_t Magic = MachO::MH_MAGIC_64;
static constexpr const uint32_t SegmentCmd = MachO::LC_SEGMENT_64;
};
class MachODebugObjectSynthesizerBase
: public GDBJITDebugInfoRegistrationPlugin::DebugSectionSynthesizer {
public:
static bool isDebugSection(Section &Sec) {
return Sec.getName().startswith("__DWARF,");
}
MachODebugObjectSynthesizerBase(LinkGraph &G, ExecutorAddr RegisterActionAddr)
: G(G), RegisterActionAddr(RegisterActionAddr) {}
virtual ~MachODebugObjectSynthesizerBase() = default;
Error preserveDebugSections() {
if (G.findSectionByName(SynthDebugSectionName)) {
LLVM_DEBUG({
dbgs() << "MachODebugObjectSynthesizer skipping graph " << G.getName()
<< " which contains an unexpected existing "
<< SynthDebugSectionName << " section.\n";
});
return Error::success();
}
LLVM_DEBUG({
dbgs() << "MachODebugObjectSynthesizer visiting graph " << G.getName()
<< "\n";
});
for (auto &Sec : G.sections()) {
if (!isDebugSection(Sec))
continue;
// Preserve blocks in this debug section by marking one existing symbol
// live for each block, and introducing a new live, anonymous symbol for
// each currently unreferenced block.
LLVM_DEBUG({
dbgs() << " Preserving debug section " << Sec.getName() << "\n";
});
SmallSet<Block *, 8> PreservedBlocks;
for (auto *Sym : Sec.symbols()) {
bool NewPreservedBlock =
PreservedBlocks.insert(&Sym->getBlock()).second;
if (NewPreservedBlock)
Sym->setLive(true);
}
for (auto *B : Sec.blocks())
if (!PreservedBlocks.count(B))
G.addAnonymousSymbol(*B, 0, 0, false, true);
}
return Error::success();
}
protected:
LinkGraph &G;
ExecutorAddr RegisterActionAddr;
};
template <typename MachOTraits>
class MachODebugObjectSynthesizer : public MachODebugObjectSynthesizerBase {
private:
class MachOStructWriter {
public:
MachOStructWriter(MutableArrayRef<char> Buffer) : Buffer(Buffer) {}
size_t getOffset() const { return Offset; }
template <typename MachOStruct> void write(MachOStruct S) {
assert(Offset + sizeof(S) <= Buffer.size() &&
"Container block overflow while constructing debug MachO");
if (MachOTraits::Endianness != support::endian::system_endianness())
MachO::swapStruct(S);
memcpy(Buffer.data() + Offset, &S, sizeof(S));
Offset += sizeof(S);
}
private:
MutableArrayRef<char> Buffer;
size_t Offset = 0;
};
public:
using MachODebugObjectSynthesizerBase::MachODebugObjectSynthesizerBase;
Error startSynthesis() override {
LLVM_DEBUG({
dbgs() << "Creating " << SynthDebugSectionName << " for " << G.getName()
<< "\n";
});
auto &SDOSec = G.createSection(SynthDebugSectionName, MemProt::Read);
struct DebugSectionInfo {
Section *Sec = nullptr;
StringRef SegName;
StringRef SecName;
uint64_t Alignment = 0;
orc::ExecutorAddr StartAddr;
uint64_t Size = 0;
};
SmallVector<DebugSectionInfo, 12> DebugSecInfos;
size_t NumSections = 0;
for (auto &Sec : G.sections()) {
if (Sec.blocks().empty())
continue;
++NumSections;
if (isDebugSection(Sec)) {
size_t SepPos = Sec.getName().find(',');
if (SepPos > 16 || (Sec.getName().size() - (SepPos + 1) > 16)) {
LLVM_DEBUG({
dbgs() << "Skipping debug object synthesis for graph "
<< G.getName()
<< ": encountered non-standard DWARF section name \""
<< Sec.getName() << "\"\n";
});
return Error::success();
}
DebugSecInfos.push_back({&Sec, Sec.getName().substr(0, SepPos),
Sec.getName().substr(SepPos + 1), 0,
orc::ExecutorAddr(), 0});
} else {
NonDebugSections.push_back(&Sec);
// If the first block in the section has a non-zero alignment offset
// then we need to add a padding block, since the section command in
// the header doesn't allow for aligment offsets.
SectionRange R(Sec);
if (!R.empty()) {
auto &FB = *R.getFirstBlock();
if (FB.getAlignmentOffset() != 0) {
auto Padding = G.allocateBuffer(FB.getAlignmentOffset());
memset(Padding.data(), 0, Padding.size());
G.createContentBlock(Sec, Padding,
FB.getAddress() - FB.getAlignmentOffset(),
FB.getAlignment(), 0);
}
}
}
}
// Create container block.
size_t SectionsCmdSize =
sizeof(typename MachOTraits::Section) * NumSections;
size_t SegmentLCSize =
sizeof(typename MachOTraits::SegmentLC) + SectionsCmdSize;
size_t ContainerBlockSize =
sizeof(typename MachOTraits::Header) + SegmentLCSize;
auto ContainerBlockContent = G.allocateBuffer(ContainerBlockSize);
MachOContainerBlock = &G.createMutableContentBlock(
SDOSec, ContainerBlockContent, orc::ExecutorAddr(), 8, 0);
// Copy debug section blocks and symbols.
orc::ExecutorAddr NextBlockAddr(MachOContainerBlock->getSize());
for (auto &SI : DebugSecInfos) {
assert(!SI.Sec->blocks().empty() && "Empty debug info section?");
// Update addresses in debug section.
LLVM_DEBUG({
dbgs() << " Appending " << SI.Sec->getName() << " ("
<< SI.Sec->blocks_size() << " block(s)) at "
<< formatv("{0:x8}", NextBlockAddr) << "\n";
});
for (auto *B : SI.Sec->blocks()) {
NextBlockAddr = alignToBlock(NextBlockAddr, *B);
B->setAddress(NextBlockAddr);
NextBlockAddr += B->getSize();
}
auto &FirstBlock = **SI.Sec->blocks().begin();
if (FirstBlock.getAlignmentOffset() != 0)
return make_error<StringError>(
"First block in " + SI.Sec->getName() +
" section has non-zero alignment offset",
inconvertibleErrorCode());
if (FirstBlock.getAlignment() > std::numeric_limits<uint32_t>::max())
return make_error<StringError>("First block in " + SI.Sec->getName() +
" has alignment >4Gb",
inconvertibleErrorCode());
SI.Alignment = FirstBlock.getAlignment();
SI.StartAddr = FirstBlock.getAddress();
SI.Size = NextBlockAddr - SI.StartAddr;
G.mergeSections(SDOSec, *SI.Sec);
SI.Sec = nullptr;
}
size_t DebugSectionsSize =
NextBlockAddr - orc::ExecutorAddr(MachOContainerBlock->getSize());
// Write MachO header and debug section load commands.
MachOStructWriter Writer(MachOContainerBlock->getAlreadyMutableContent());
typename MachOTraits::Header Hdr;
memset(&Hdr, 0, sizeof(Hdr));
Hdr.magic = MachOTraits::Magic;
switch (G.getTargetTriple().getArch()) {
case Triple::x86_64:
Hdr.cputype = MachO::CPU_TYPE_X86_64;
Hdr.cpusubtype = MachO::CPU_SUBTYPE_X86_64_ALL;
break;
case Triple::aarch64:
Hdr.cputype = MachO::CPU_TYPE_ARM64;
Hdr.cpusubtype = MachO::CPU_SUBTYPE_ARM64_ALL;
break;
default:
llvm_unreachable("Unsupported architecture");
}
Hdr.filetype = MachO::MH_OBJECT;
Hdr.ncmds = 1;
Hdr.sizeofcmds = SegmentLCSize;
Hdr.flags = 0;
Writer.write(Hdr);
typename MachOTraits::SegmentLC SegLC;
memset(&SegLC, 0, sizeof(SegLC));
SegLC.cmd = MachOTraits::SegmentCmd;
SegLC.cmdsize = SegmentLCSize;
SegLC.vmaddr = ContainerBlockSize;
SegLC.vmsize = DebugSectionsSize;
SegLC.fileoff = ContainerBlockSize;
SegLC.filesize = DebugSectionsSize;
SegLC.maxprot =
MachO::VM_PROT_READ | MachO::VM_PROT_WRITE | MachO::VM_PROT_EXECUTE;
SegLC.initprot =
MachO::VM_PROT_READ | MachO::VM_PROT_WRITE | MachO::VM_PROT_EXECUTE;
SegLC.nsects = NumSections;
SegLC.flags = 0;
Writer.write(SegLC);
StringSet<> ExistingLongNames;
for (auto &SI : DebugSecInfos) {
typename MachOTraits::Section Sec;
memset(&Sec, 0, sizeof(Sec));
memcpy(Sec.sectname, SI.SecName.data(), SI.SecName.size());
memcpy(Sec.segname, SI.SegName.data(), SI.SegName.size());
Sec.addr = SI.StartAddr.getValue();
Sec.size = SI.Size;
Sec.offset = SI.StartAddr.getValue();
Sec.align = SI.Alignment;
Sec.reloff = 0;
Sec.nreloc = 0;
Sec.flags = MachO::S_ATTR_DEBUG;
Writer.write(Sec);
}
// Set MachOContainerBlock to indicate success to
// completeSynthesisAndRegister.
NonDebugSectionsStart = Writer.getOffset();
return Error::success();
}
Error completeSynthesisAndRegister() override {
if (!MachOContainerBlock) {
LLVM_DEBUG({
dbgs() << "Not writing MachO debug object header for " << G.getName()
<< " since createDebugSection failed\n";
});
return Error::success();
}
LLVM_DEBUG({
dbgs() << "Writing MachO debug object header for " << G.getName() << "\n";
});
MachOStructWriter Writer(
MachOContainerBlock->getAlreadyMutableContent().drop_front(
NonDebugSectionsStart));
unsigned LongSectionNameIdx = 0;
for (auto *Sec : NonDebugSections) {
size_t SepPos = Sec->getName().find(',');
StringRef SegName, SecName;
std::string CustomSecName;
if ((SepPos == StringRef::npos && Sec->getName().size() <= 16)) {
// No embedded segment name, short section name.
SegName = "__JITLINK_CUSTOM";
SecName = Sec->getName();
} else if (SepPos < 16 && (Sec->getName().size() - (SepPos + 1) <= 16)) {
// Canonical embedded segment and section name.
SegName = Sec->getName().substr(0, SepPos);
SecName = Sec->getName().substr(SepPos + 1);
} else {
// Long section name that needs to be truncated.
assert(Sec->getName().size() > 16 &&
"Short section name should have been handled above");
SegName = "__JITLINK_CUSTOM";
auto IdxStr = std::to_string(++LongSectionNameIdx);
CustomSecName = Sec->getName().substr(0, 15 - IdxStr.size()).str();
CustomSecName += ".";
CustomSecName += IdxStr;
SecName = StringRef(CustomSecName.data(), 16);
}
SectionRange R(*Sec);
if (R.getFirstBlock()->getAlignmentOffset() != 0)
return make_error<StringError>(
"While building MachO debug object for " + G.getName() +
" first block has non-zero alignment offset",
inconvertibleErrorCode());
typename MachOTraits::Section SecCmd;
memset(&SecCmd, 0, sizeof(SecCmd));
memcpy(SecCmd.sectname, SecName.data(), SecName.size());
memcpy(SecCmd.segname, SegName.data(), SegName.size());
SecCmd.addr = R.getStart().getValue();
SecCmd.size = R.getSize();
SecCmd.offset = 0;
SecCmd.align = R.getFirstBlock()->getAlignment();
SecCmd.reloff = 0;
SecCmd.nreloc = 0;
SecCmd.flags = 0;
Writer.write(SecCmd);
}
SectionRange R(MachOContainerBlock->getSection());
G.allocActions().push_back(
{cantFail(shared::WrapperFunctionCall::Create<
shared::SPSArgList<shared::SPSExecutorAddrRange>>(
RegisterActionAddr, R.getRange())),
{}});
return Error::success();
}
private:
Block *MachOContainerBlock = nullptr;
SmallVector<Section *, 16> NonDebugSections;
size_t NonDebugSectionsStart = 0;
};
} // end anonymous namespace
namespace llvm {
namespace orc {
Expected<std::unique_ptr<GDBJITDebugInfoRegistrationPlugin>>
GDBJITDebugInfoRegistrationPlugin::Create(ExecutionSession &ES,
JITDylib &ProcessJD,
const Triple &TT) {
auto RegisterActionAddr =
TT.isOSBinFormatMachO()
? ES.intern("_llvm_orc_registerJITLoaderGDBAllocAction")
: ES.intern("llvm_orc_registerJITLoaderGDBAllocAction");
if (auto RegisterSym = ES.lookup({&ProcessJD}, RegisterActionAddr))
return std::make_unique<GDBJITDebugInfoRegistrationPlugin>(
RegisterSym->getAddress());
else
return RegisterSym.takeError();
}
Error GDBJITDebugInfoRegistrationPlugin::notifyFailed(
MaterializationResponsibility &MR) {
return Error::success();
}
Error GDBJITDebugInfoRegistrationPlugin::notifyRemovingResources(
JITDylib &JD, ResourceKey K) {
return Error::success();
}
void GDBJITDebugInfoRegistrationPlugin::notifyTransferringResources(
JITDylib &JD, ResourceKey DstKey, ResourceKey SrcKey) {}
void GDBJITDebugInfoRegistrationPlugin::modifyPassConfig(
MaterializationResponsibility &MR, LinkGraph &LG,
PassConfiguration &PassConfig) {
if (LG.getTargetTriple().getObjectFormat() == Triple::MachO)
modifyPassConfigForMachO(MR, LG, PassConfig);
else {
LLVM_DEBUG({
dbgs() << "GDBJITDebugInfoRegistrationPlugin skipping unspported graph "
<< LG.getName() << "(triple = " << LG.getTargetTriple().str()
<< "\n";
});
}
}
void GDBJITDebugInfoRegistrationPlugin::modifyPassConfigForMachO(
MaterializationResponsibility &MR, jitlink::LinkGraph &LG,
jitlink::PassConfiguration &PassConfig) {
switch (LG.getTargetTriple().getArch()) {
case Triple::x86_64:
case Triple::aarch64:
// Supported, continue.
assert(LG.getPointerSize() == 8 && "Graph has incorrect pointer size");
assert(LG.getEndianness() == support::little &&
"Graph has incorrect endianness");
break;
default:
// Unsupported.
LLVM_DEBUG({
dbgs() << "GDBJITDebugInfoRegistrationPlugin skipping unsupported "
<< "MachO graph " << LG.getName()
<< "(triple = " << LG.getTargetTriple().str()
<< ", pointer size = " << LG.getPointerSize() << ", endianness = "
<< (LG.getEndianness() == support::big ? "big" : "little")
<< ")\n";
});
return;
}
// Scan for debug sections. If we find one then install passes.
bool HasDebugSections = false;
for (auto &Sec : LG.sections())
if (MachODebugObjectSynthesizerBase::isDebugSection(Sec)) {
HasDebugSections = true;
break;
}
if (HasDebugSections) {
LLVM_DEBUG({
dbgs() << "GDBJITDebugInfoRegistrationPlugin: Graph " << LG.getName()
<< " contains debug info. Installing debugger support passes.\n";
});
auto MDOS = std::make_shared<MachODebugObjectSynthesizer<MachO64LE>>(
LG, RegisterActionAddr);
PassConfig.PrePrunePasses.push_back(
[=](LinkGraph &G) { return MDOS->preserveDebugSections(); });
PassConfig.PostPrunePasses.push_back(
[=](LinkGraph &G) { return MDOS->startSynthesis(); });
PassConfig.PreFixupPasses.push_back(
[=](LinkGraph &G) { return MDOS->completeSynthesisAndRegister(); });
} else {
LLVM_DEBUG({
dbgs() << "GDBJITDebugInfoRegistrationPlugin: Graph " << LG.getName()
<< " contains no debug info. Skipping.\n";
});
}
}
} // namespace orc
} // namespace llvm