alx32 5147e5941d
[GSYM] Callsites: Add data format support and loading from YAML (#109781)
This PR adds support in the gSYM format for call site information and
adds support for loading call sites from a YAML file. The support for
YAML input is mostly for testing purposes - so we have a way to test the
functionality.

Note that this data is not currently used in the gSYM tooling - the
logic to use call sites will be added in a later PR.

The reason why we need call site information in gSYM files is so that we
can support better call stack function disambiguation in the case where
multiple functions have been merged due to optimization (linker ICF).
When resolving a merged function on the callstack, we can use the call
site information of the calling function to narrow down the actual
function that is being called, from the set of all merged functions.

See [this
RFC](https://discourse.llvm.org/t/rfc-extending-gsym-format-with-call-site-information-for-merged-function-disambiguation/80682)
for more details on this change.
2024-11-26 16:07:40 -08:00

518 lines
18 KiB
C++

//===- GsymReader.cpp -----------------------------------------------------===//
//
// 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/DebugInfo/GSYM/GsymReader.h"
#include <assert.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include "llvm/DebugInfo/GSYM/InlineInfo.h"
#include "llvm/DebugInfo/GSYM/LineTable.h"
#include "llvm/Support/BinaryStreamReader.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/MemoryBuffer.h"
using namespace llvm;
using namespace gsym;
GsymReader::GsymReader(std::unique_ptr<MemoryBuffer> Buffer)
: MemBuffer(std::move(Buffer)), Endian(llvm::endianness::native) {}
GsymReader::GsymReader(GsymReader &&RHS) = default;
GsymReader::~GsymReader() = default;
llvm::Expected<GsymReader> GsymReader::openFile(StringRef Filename) {
// Open the input file and return an appropriate error if needed.
ErrorOr<std::unique_ptr<MemoryBuffer>> BuffOrErr =
MemoryBuffer::getFileOrSTDIN(Filename);
auto Err = BuffOrErr.getError();
if (Err)
return llvm::errorCodeToError(Err);
return create(BuffOrErr.get());
}
llvm::Expected<GsymReader> GsymReader::copyBuffer(StringRef Bytes) {
auto MemBuffer = MemoryBuffer::getMemBufferCopy(Bytes, "GSYM bytes");
return create(MemBuffer);
}
llvm::Expected<llvm::gsym::GsymReader>
GsymReader::create(std::unique_ptr<MemoryBuffer> &MemBuffer) {
if (!MemBuffer)
return createStringError(std::errc::invalid_argument,
"invalid memory buffer");
GsymReader GR(std::move(MemBuffer));
llvm::Error Err = GR.parse();
if (Err)
return std::move(Err);
return std::move(GR);
}
llvm::Error
GsymReader::parse() {
BinaryStreamReader FileData(MemBuffer->getBuffer(), llvm::endianness::native);
// Check for the magic bytes. This file format is designed to be mmap'ed
// into a process and accessed as read only. This is done for performance
// and efficiency for symbolicating and parsing GSYM data.
if (FileData.readObject(Hdr))
return createStringError(std::errc::invalid_argument,
"not enough data for a GSYM header");
const auto HostByteOrder = llvm::endianness::native;
switch (Hdr->Magic) {
case GSYM_MAGIC:
Endian = HostByteOrder;
break;
case GSYM_CIGAM:
// This is a GSYM file, but not native endianness.
Endian = sys::IsBigEndianHost ? llvm::endianness::little
: llvm::endianness::big;
Swap.reset(new SwappedData);
break;
default:
return createStringError(std::errc::invalid_argument,
"not a GSYM file");
}
bool DataIsLittleEndian = HostByteOrder != llvm::endianness::little;
// Read a correctly byte swapped header if we need to.
if (Swap) {
DataExtractor Data(MemBuffer->getBuffer(), DataIsLittleEndian, 4);
if (auto ExpectedHdr = Header::decode(Data))
Swap->Hdr = ExpectedHdr.get();
else
return ExpectedHdr.takeError();
Hdr = &Swap->Hdr;
}
// Detect errors in the header and report any that are found. If we make it
// past this without errors, we know we have a good magic value, a supported
// version number, verified address offset size and a valid UUID size.
if (Error Err = Hdr->checkForError())
return Err;
if (!Swap) {
// This is the native endianness case that is most common and optimized for
// efficient lookups. Here we just grab pointers to the native data and
// use ArrayRef objects to allow efficient read only access.
// Read the address offsets.
if (FileData.padToAlignment(Hdr->AddrOffSize) ||
FileData.readArray(AddrOffsets,
Hdr->NumAddresses * Hdr->AddrOffSize))
return createStringError(std::errc::invalid_argument,
"failed to read address table");
// Read the address info offsets.
if (FileData.padToAlignment(4) ||
FileData.readArray(AddrInfoOffsets, Hdr->NumAddresses))
return createStringError(std::errc::invalid_argument,
"failed to read address info offsets table");
// Read the file table.
uint32_t NumFiles = 0;
if (FileData.readInteger(NumFiles) || FileData.readArray(Files, NumFiles))
return createStringError(std::errc::invalid_argument,
"failed to read file table");
// Get the string table.
FileData.setOffset(Hdr->StrtabOffset);
if (FileData.readFixedString(StrTab.Data, Hdr->StrtabSize))
return createStringError(std::errc::invalid_argument,
"failed to read string table");
} else {
// This is the non native endianness case that is not common and not
// optimized for lookups. Here we decode the important tables into local
// storage and then set the ArrayRef objects to point to these swapped
// copies of the read only data so lookups can be as efficient as possible.
DataExtractor Data(MemBuffer->getBuffer(), DataIsLittleEndian, 4);
// Read the address offsets.
uint64_t Offset = alignTo(sizeof(Header), Hdr->AddrOffSize);
Swap->AddrOffsets.resize(Hdr->NumAddresses * Hdr->AddrOffSize);
switch (Hdr->AddrOffSize) {
case 1:
if (!Data.getU8(&Offset, Swap->AddrOffsets.data(), Hdr->NumAddresses))
return createStringError(std::errc::invalid_argument,
"failed to read address table");
break;
case 2:
if (!Data.getU16(&Offset,
reinterpret_cast<uint16_t *>(Swap->AddrOffsets.data()),
Hdr->NumAddresses))
return createStringError(std::errc::invalid_argument,
"failed to read address table");
break;
case 4:
if (!Data.getU32(&Offset,
reinterpret_cast<uint32_t *>(Swap->AddrOffsets.data()),
Hdr->NumAddresses))
return createStringError(std::errc::invalid_argument,
"failed to read address table");
break;
case 8:
if (!Data.getU64(&Offset,
reinterpret_cast<uint64_t *>(Swap->AddrOffsets.data()),
Hdr->NumAddresses))
return createStringError(std::errc::invalid_argument,
"failed to read address table");
}
AddrOffsets = ArrayRef<uint8_t>(Swap->AddrOffsets);
// Read the address info offsets.
Offset = alignTo(Offset, 4);
Swap->AddrInfoOffsets.resize(Hdr->NumAddresses);
if (Data.getU32(&Offset, Swap->AddrInfoOffsets.data(), Hdr->NumAddresses))
AddrInfoOffsets = ArrayRef<uint32_t>(Swap->AddrInfoOffsets);
else
return createStringError(std::errc::invalid_argument,
"failed to read address table");
// Read the file table.
const uint32_t NumFiles = Data.getU32(&Offset);
if (NumFiles > 0) {
Swap->Files.resize(NumFiles);
if (Data.getU32(&Offset, &Swap->Files[0].Dir, NumFiles*2))
Files = ArrayRef<FileEntry>(Swap->Files);
else
return createStringError(std::errc::invalid_argument,
"failed to read file table");
}
// Get the string table.
StrTab.Data = MemBuffer->getBuffer().substr(Hdr->StrtabOffset,
Hdr->StrtabSize);
if (StrTab.Data.empty())
return createStringError(std::errc::invalid_argument,
"failed to read string table");
}
return Error::success();
}
const Header &GsymReader::getHeader() const {
// The only way to get a GsymReader is from GsymReader::openFile(...) or
// GsymReader::copyBuffer() and the header must be valid and initialized to
// a valid pointer value, so the assert below should not trigger.
assert(Hdr);
return *Hdr;
}
std::optional<uint64_t> GsymReader::getAddress(size_t Index) const {
switch (Hdr->AddrOffSize) {
case 1: return addressForIndex<uint8_t>(Index);
case 2: return addressForIndex<uint16_t>(Index);
case 4: return addressForIndex<uint32_t>(Index);
case 8: return addressForIndex<uint64_t>(Index);
}
return std::nullopt;
}
std::optional<uint64_t> GsymReader::getAddressInfoOffset(size_t Index) const {
const auto NumAddrInfoOffsets = AddrInfoOffsets.size();
if (Index < NumAddrInfoOffsets)
return AddrInfoOffsets[Index];
return std::nullopt;
}
Expected<uint64_t>
GsymReader::getAddressIndex(const uint64_t Addr) const {
if (Addr >= Hdr->BaseAddress) {
const uint64_t AddrOffset = Addr - Hdr->BaseAddress;
std::optional<uint64_t> AddrOffsetIndex;
switch (Hdr->AddrOffSize) {
case 1:
AddrOffsetIndex = getAddressOffsetIndex<uint8_t>(AddrOffset);
break;
case 2:
AddrOffsetIndex = getAddressOffsetIndex<uint16_t>(AddrOffset);
break;
case 4:
AddrOffsetIndex = getAddressOffsetIndex<uint32_t>(AddrOffset);
break;
case 8:
AddrOffsetIndex = getAddressOffsetIndex<uint64_t>(AddrOffset);
break;
default:
return createStringError(std::errc::invalid_argument,
"unsupported address offset size %u",
Hdr->AddrOffSize);
}
if (AddrOffsetIndex)
return *AddrOffsetIndex;
}
return createStringError(std::errc::invalid_argument,
"address 0x%" PRIx64 " is not in GSYM", Addr);
}
llvm::Expected<DataExtractor>
GsymReader::getFunctionInfoDataForAddress(uint64_t Addr,
uint64_t &FuncStartAddr) const {
Expected<uint64_t> ExpectedAddrIdx = getAddressIndex(Addr);
if (!ExpectedAddrIdx)
return ExpectedAddrIdx.takeError();
const uint64_t FirstAddrIdx = *ExpectedAddrIdx;
// The AddrIdx is the first index of the function info entries that match
// \a Addr. We need to iterate over all function info objects that start with
// the same address until we find a range that contains \a Addr.
std::optional<uint64_t> FirstFuncStartAddr;
const size_t NumAddresses = getNumAddresses();
for (uint64_t AddrIdx = FirstAddrIdx; AddrIdx < NumAddresses; ++AddrIdx) {
auto ExpextedData = getFunctionInfoDataAtIndex(AddrIdx, FuncStartAddr);
// If there was an error, return the error.
if (!ExpextedData)
return ExpextedData;
// Remember the first function start address if it hasn't already been set.
// If it is already valid, check to see if it matches the first function
// start address and only continue if it matches.
if (FirstFuncStartAddr.has_value()) {
if (*FirstFuncStartAddr != FuncStartAddr)
break; // Done with consecutive function entries with same address.
} else {
FirstFuncStartAddr = FuncStartAddr;
}
// Make sure the current function address ranges contains \a Addr.
// Some symbols on Darwin don't have valid sizes, so if we run into a
// symbol with zero size, then we have found a match for our address.
// The first thing the encoding of a FunctionInfo object is the function
// size.
uint64_t Offset = 0;
uint32_t FuncSize = ExpextedData->getU32(&Offset);
if (FuncSize == 0 ||
AddressRange(FuncStartAddr, FuncStartAddr + FuncSize).contains(Addr))
return ExpextedData;
}
return createStringError(std::errc::invalid_argument,
"address 0x%" PRIx64 " is not in GSYM", Addr);
}
llvm::Expected<DataExtractor>
GsymReader::getFunctionInfoDataAtIndex(uint64_t AddrIdx,
uint64_t &FuncStartAddr) const {
if (AddrIdx >= getNumAddresses())
return createStringError(std::errc::invalid_argument,
"invalid address index %" PRIu64, AddrIdx);
const uint32_t AddrInfoOffset = AddrInfoOffsets[AddrIdx];
assert((Endian == endianness::big || Endian == endianness::little) &&
"Endian must be either big or little");
StringRef Bytes = MemBuffer->getBuffer().substr(AddrInfoOffset);
if (Bytes.empty())
return createStringError(std::errc::invalid_argument,
"invalid address info offset 0x%" PRIx32,
AddrInfoOffset);
std::optional<uint64_t> OptFuncStartAddr = getAddress(AddrIdx);
if (!OptFuncStartAddr)
return createStringError(std::errc::invalid_argument,
"failed to extract address[%" PRIu64 "]", AddrIdx);
FuncStartAddr = *OptFuncStartAddr;
return DataExtractor(Bytes, Endian == llvm::endianness::little, 4);
}
llvm::Expected<FunctionInfo> GsymReader::getFunctionInfo(uint64_t Addr) const {
uint64_t FuncStartAddr = 0;
if (auto ExpectedData = getFunctionInfoDataForAddress(Addr, FuncStartAddr))
return FunctionInfo::decode(*ExpectedData, FuncStartAddr);
else
return ExpectedData.takeError();
}
llvm::Expected<FunctionInfo>
GsymReader::getFunctionInfoAtIndex(uint64_t Idx) const {
uint64_t FuncStartAddr = 0;
if (auto ExpectedData = getFunctionInfoDataAtIndex(Idx, FuncStartAddr))
return FunctionInfo::decode(*ExpectedData, FuncStartAddr);
else
return ExpectedData.takeError();
}
llvm::Expected<LookupResult> GsymReader::lookup(uint64_t Addr) const {
uint64_t FuncStartAddr = 0;
if (auto ExpectedData = getFunctionInfoDataForAddress(Addr, FuncStartAddr))
return FunctionInfo::lookup(*ExpectedData, *this, FuncStartAddr, Addr);
else
return ExpectedData.takeError();
}
void GsymReader::dump(raw_ostream &OS) {
const auto &Header = getHeader();
// Dump the GSYM header.
OS << Header << "\n";
// Dump the address table.
OS << "Address Table:\n";
OS << "INDEX OFFSET";
switch (Hdr->AddrOffSize) {
case 1: OS << "8 "; break;
case 2: OS << "16"; break;
case 4: OS << "32"; break;
case 8: OS << "64"; break;
default: OS << "??"; break;
}
OS << " (ADDRESS)\n";
OS << "====== =============================== \n";
for (uint32_t I = 0; I < Header.NumAddresses; ++I) {
OS << format("[%4u] ", I);
switch (Hdr->AddrOffSize) {
case 1: OS << HEX8(getAddrOffsets<uint8_t>()[I]); break;
case 2: OS << HEX16(getAddrOffsets<uint16_t>()[I]); break;
case 4: OS << HEX32(getAddrOffsets<uint32_t>()[I]); break;
case 8: OS << HEX32(getAddrOffsets<uint64_t>()[I]); break;
default: break;
}
OS << " (" << HEX64(*getAddress(I)) << ")\n";
}
// Dump the address info offsets table.
OS << "\nAddress Info Offsets:\n";
OS << "INDEX Offset\n";
OS << "====== ==========\n";
for (uint32_t I = 0; I < Header.NumAddresses; ++I)
OS << format("[%4u] ", I) << HEX32(AddrInfoOffsets[I]) << "\n";
// Dump the file table.
OS << "\nFiles:\n";
OS << "INDEX DIRECTORY BASENAME PATH\n";
OS << "====== ========== ========== ==============================\n";
for (uint32_t I = 0; I < Files.size(); ++I) {
OS << format("[%4u] ", I) << HEX32(Files[I].Dir) << ' '
<< HEX32(Files[I].Base) << ' ';
dump(OS, getFile(I));
OS << "\n";
}
OS << "\n" << StrTab << "\n";
for (uint32_t I = 0; I < Header.NumAddresses; ++I) {
OS << "FunctionInfo @ " << HEX32(AddrInfoOffsets[I]) << ": ";
if (auto FI = getFunctionInfoAtIndex(I))
dump(OS, *FI);
else
logAllUnhandledErrors(FI.takeError(), OS, "FunctionInfo:");
}
}
void GsymReader::dump(raw_ostream &OS, const FunctionInfo &FI,
uint32_t Indent) {
OS.indent(Indent);
OS << FI.Range << " \"" << getString(FI.Name) << "\"\n";
if (FI.OptLineTable)
dump(OS, *FI.OptLineTable, Indent);
if (FI.Inline)
dump(OS, *FI.Inline, Indent);
if (FI.MergedFunctions) {
assert(Indent == 0 && "MergedFunctionsInfo should only exist at top level");
dump(OS, *FI.MergedFunctions);
}
if (FI.CallSites)
dump(OS, *FI.CallSites);
}
void GsymReader::dump(raw_ostream &OS, const MergedFunctionsInfo &MFI) {
for (uint32_t inx = 0; inx < MFI.MergedFunctions.size(); inx++) {
OS << "++ Merged FunctionInfos[" << inx << "]:\n";
dump(OS, MFI.MergedFunctions[inx], 4);
}
}
void GsymReader::dump(raw_ostream &OS, const CallSiteInfo &CSI) {
OS << HEX16(CSI.ReturnOffset);
std::string Flags;
auto addFlag = [&](const char *Flag) {
if (!Flags.empty())
Flags += " | ";
Flags += Flag;
};
if (CSI.Flags == CallSiteInfo::Flags::None)
Flags = "None";
else {
if (CSI.Flags & CallSiteInfo::Flags::InternalCall)
addFlag("InternalCall");
if (CSI.Flags & CallSiteInfo::Flags::ExternalCall)
addFlag("ExternalCall");
}
OS << " Flags[" << Flags << "]";
if (!CSI.MatchRegex.empty()) {
OS << " MatchRegex[";
for (uint32_t i = 0; i < CSI.MatchRegex.size(); ++i) {
if (i > 0)
OS << ";";
OS << getString(CSI.MatchRegex[i]);
}
OS << "]";
}
}
void GsymReader::dump(raw_ostream &OS, const CallSiteInfoCollection &CSIC) {
OS << "CallSites (by relative return offset):\n";
for (const auto &CS : CSIC.CallSites) {
OS.indent(2);
dump(OS, CS);
OS << "\n";
}
}
void GsymReader::dump(raw_ostream &OS, const LineTable &LT, uint32_t Indent) {
OS.indent(Indent);
OS << "LineTable:\n";
for (auto &LE: LT) {
OS.indent(Indent);
OS << " " << HEX64(LE.Addr) << ' ';
if (LE.File)
dump(OS, getFile(LE.File));
OS << ':' << LE.Line << '\n';
}
}
void GsymReader::dump(raw_ostream &OS, const InlineInfo &II, uint32_t Indent) {
if (Indent == 0)
OS << "InlineInfo:\n";
else
OS.indent(Indent);
OS << II.Ranges << ' ' << getString(II.Name);
if (II.CallFile != 0) {
if (auto File = getFile(II.CallFile)) {
OS << " called from ";
dump(OS, File);
OS << ':' << II.CallLine;
}
}
OS << '\n';
for (const auto &ChildII: II.Children)
dump(OS, ChildII, Indent + 2);
}
void GsymReader::dump(raw_ostream &OS, std::optional<FileEntry> FE) {
if (FE) {
// IF we have the file from index 0, then don't print anything
if (FE->Dir == 0 && FE->Base == 0)
return;
StringRef Dir = getString(FE->Dir);
StringRef Base = getString(FE->Base);
if (!Dir.empty()) {
OS << Dir;
if (Dir.contains('\\') && !Dir.contains('/'))
OS << '\\';
else
OS << '/';
}
if (!Base.empty()) {
OS << Base;
}
if (!Dir.empty() || !Base.empty())
return;
}
OS << "<invalid-file>";
}