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[Object][Archive][NFC] Create all symbolic files objects before calculating offsets. #85229

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merged 1 commit into from
Mar 15, 2024
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[Object][Archive][NFC] Create all symbolic files objects before calculating offsets. #85229

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58 changes: 23 additions & 35 deletions llvm/lib/Object/ArchiveWriter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -795,23 +795,31 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
Entry.second = Entry.second > 1 ? 1 : 0;
}

std::vector<std::unique_ptr<SymbolicFile>> SymFiles;

if (NeedSymbols != SymtabWritingMode::NoSymtab || isAIXBigArchive(Kind)) {
for (const NewArchiveMember &M : NewMembers) {
Expected<std::unique_ptr<SymbolicFile>> SymFileOrErr =
getSymbolicFile(M.Buf->getMemBufferRef(), Context);
if (!SymFileOrErr)
return createFileError(M.MemberName, SymFileOrErr.takeError());
SymFiles.push_back(std::move(*SymFileOrErr));
}
}

// The big archive format needs to know the offset of the previous member
// header.
uint64_t PrevOffset = 0;
uint64_t NextMemHeadPadSize = 0;
std::unique_ptr<SymbolicFile> CurSymFile;
std::unique_ptr<SymbolicFile> NextSymFile;
uint16_t Index = 0;

for (auto M = NewMembers.begin(); M < NewMembers.end(); ++M) {
for (uint32_t Index = 0; Index < NewMembers.size(); ++Index) {
const NewArchiveMember *M = &NewMembers[Index];
std::string Header;
raw_string_ostream Out(Header);

MemoryBufferRef Buf = M->Buf->getMemBufferRef();
StringRef Data = Thin ? "" : Buf.getBuffer();

Index++;

// ld64 expects the members to be 8-byte aligned for 64-bit content and at
// least 4-byte aligned for 32-bit content. Opt for the larger encoding
// uniformly. This matches the behaviour with cctools and ensures that ld64
Expand All @@ -837,29 +845,9 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
std::move(StringMsg), object::object_error::parse_failed);
}

if (NeedSymbols != SymtabWritingMode::NoSymtab || isAIXBigArchive(Kind)) {
auto SetNextSymFile = [&NextSymFile,
&Context](MemoryBufferRef Buf,
StringRef MemberName) -> Error {
Expected<std::unique_ptr<SymbolicFile>> SymFileOrErr =
getSymbolicFile(Buf, Context);
if (!SymFileOrErr)
return createFileError(MemberName, SymFileOrErr.takeError());
NextSymFile = std::move(*SymFileOrErr);
return Error::success();
};

if (M == NewMembers.begin())
if (Error Err = SetNextSymFile(Buf, M->MemberName))
return std::move(Err);

CurSymFile = std::move(NextSymFile);

if ((M + 1) != NewMembers.end())
if (Error Err = SetNextSymFile((M + 1)->Buf->getMemBufferRef(),
(M + 1)->MemberName))
return std::move(Err);
}
std::unique_ptr<SymbolicFile> CurSymFile;
if (!SymFiles.empty())
CurSymFile = std::move(SymFiles[Index]);

// In the big archive file format, we need to calculate and include the next
// member offset and previous member offset in the file member header.
Expand All @@ -880,13 +868,13 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,

// If there is another member file after this, we need to calculate the
// padding before the header.
if ((M + 1) != NewMembers.end()) {
uint64_t OffsetToNextMemData = NextOffset +
sizeof(object::BigArMemHdrType) +
alignTo((M + 1)->MemberName.size(), 2);
if (Index + 1 != SymFiles.size()) {
uint64_t OffsetToNextMemData =
NextOffset + sizeof(object::BigArMemHdrType) +
alignTo(NewMembers[Index + 1].MemberName.size(), 2);
NextMemHeadPadSize =
alignToPowerOf2(OffsetToNextMemData,
getMemberAlignment(NextSymFile.get())) -
getMemberAlignment(SymFiles[Index + 1].get())) -
OffsetToNextMemData;
NextOffset += NextMemHeadPadSize;
}
Expand All @@ -902,7 +890,7 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
std::vector<unsigned> Symbols;
if (NeedSymbols != SymtabWritingMode::NoSymtab) {
Expected<std::vector<unsigned>> SymbolsOrErr =
getSymbols(CurSymFile.get(), Index, SymNames, SymMap);
getSymbols(CurSymFile.get(), Index + 1, SymNames, SymMap);
if (!SymbolsOrErr)
return createFileError(M->MemberName, SymbolsOrErr.takeError());
Symbols = std::move(*SymbolsOrErr);
Expand Down