diff options
Diffstat (limited to 'llvm/lib/Object/ArchiveWriter.cpp')
| -rw-r--r-- | llvm/lib/Object/ArchiveWriter.cpp | 65 |
1 files changed, 52 insertions, 13 deletions
diff --git a/llvm/lib/Object/ArchiveWriter.cpp b/llvm/lib/Object/ArchiveWriter.cpp index 913b74c110b3..1c7526832225 100644 --- a/llvm/lib/Object/ArchiveWriter.cpp +++ b/llvm/lib/Object/ArchiveWriter.cpp @@ -482,7 +482,8 @@ static uint64_t computeHeadersSize(object::Archive::Kind Kind, } static Expected<std::unique_ptr<SymbolicFile>> -getSymbolicFile(MemoryBufferRef Buf, LLVMContext &Context) { +getSymbolicFile(MemoryBufferRef Buf, LLVMContext &Context, + object::Archive::Kind Kind, function_ref<void(Error)> Warn) { const file_magic Type = identify_magic(Buf.getBuffer()); // Don't attempt to read non-symbolic file types. if (!object::SymbolicFile::isSymbolicFile(Type, &Context)) @@ -490,8 +491,36 @@ getSymbolicFile(MemoryBufferRef Buf, LLVMContext &Context) { if (Type == file_magic::bitcode) { auto ObjOrErr = object::SymbolicFile::createSymbolicFile( Buf, file_magic::bitcode, &Context); - if (!ObjOrErr) - return ObjOrErr.takeError(); + // An error reading a bitcode file most likely indicates that the file + // was created by a compiler from the future. Normally we don't try to + // implement forwards compatibility for bitcode files, but when creating an + // archive we can implement best-effort forwards compatibility by treating + // the file as a blob and not creating symbol index entries for it. lld and + // mold ignore the archive symbol index, so provided that you use one of + // these linkers, LTO will work as long as lld or the gold plugin is newer + // than the compiler. We only ignore errors if the archive format is one + // that is supported by a linker that is known to ignore the index, + // otherwise there's no chance of this working so we may as well error out. + // We print a warning on read failure so that users of linkers that rely on + // the symbol index can diagnose the issue. + // + // This is the same behavior as GNU ar when the linker plugin returns an + // error when reading the input file. If the bitcode file is actually + // malformed, it will be diagnosed at link time. + if (!ObjOrErr) { + switch (Kind) { + case object::Archive::K_BSD: + case object::Archive::K_GNU: + case object::Archive::K_GNU64: + Warn(ObjOrErr.takeError()); + return nullptr; + case object::Archive::K_AIXBIG: + case object::Archive::K_COFF: + case object::Archive::K_DARWIN: + case object::Archive::K_DARWIN64: + return ObjOrErr.takeError(); + } + } return std::move(*ObjOrErr); } else { auto ObjOrErr = object::SymbolicFile::createSymbolicFile(Buf); @@ -751,7 +780,7 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames, object::Archive::Kind Kind, bool Thin, bool Deterministic, SymtabWritingMode NeedSymbols, SymMap *SymMap, LLVMContext &Context, ArrayRef<NewArchiveMember> NewMembers, - std::optional<bool> IsEC) { + std::optional<bool> IsEC, function_ref<void(Error)> Warn) { static char PaddingData[8] = {'\n', '\n', '\n', '\n', '\n', '\n', '\n', '\n'}; uint64_t MemHeadPadSize = 0; uint64_t Pos = @@ -819,8 +848,10 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames, if (NeedSymbols != SymtabWritingMode::NoSymtab || isAIXBigArchive(Kind)) { for (const NewArchiveMember &M : NewMembers) { - Expected<std::unique_ptr<SymbolicFile>> SymFileOrErr = - getSymbolicFile(M.Buf->getMemBufferRef(), Context); + Expected<std::unique_ptr<SymbolicFile>> SymFileOrErr = getSymbolicFile( + M.Buf->getMemBufferRef(), Context, Kind, [&](Error Err) { + Warn(createFileError(M.MemberName, std::move(Err))); + }); if (!SymFileOrErr) return createFileError(M.MemberName, SymFileOrErr.takeError()); SymFiles.push_back(std::move(*SymFileOrErr)); @@ -1000,7 +1031,8 @@ Expected<std::string> computeArchiveRelativePath(StringRef From, StringRef To) { static Error writeArchiveToStream(raw_ostream &Out, ArrayRef<NewArchiveMember> NewMembers, SymtabWritingMode WriteSymtab, object::Archive::Kind Kind, - bool Deterministic, bool Thin, std::optional<bool> IsEC) { + bool Deterministic, bool Thin, std::optional<bool> IsEC, + function_ref<void(Error)> Warn) { assert((!Thin || !isBSDLike(Kind)) && "Only the gnu format has a thin mode"); SmallString<0> SymNamesBuf; @@ -1022,7 +1054,7 @@ writeArchiveToStream(raw_ostream &Out, ArrayRef<NewArchiveMember> NewMembers, Expected<std::vector<MemberData>> DataOrErr = computeMemberData( StringTable, SymNames, Kind, Thin, Deterministic, WriteSymtab, - isCOFFArchive(Kind) ? &SymMap : nullptr, Context, NewMembers, IsEC); + isCOFFArchive(Kind) ? &SymMap : nullptr, Context, NewMembers, IsEC, Warn); if (Error E = DataOrErr.takeError()) return E; std::vector<MemberData> &Data = *DataOrErr; @@ -1265,11 +1297,16 @@ writeArchiveToStream(raw_ostream &Out, ArrayRef<NewArchiveMember> NewMembers, return Error::success(); } +void warnToStderr(Error Err) { + llvm::logAllUnhandledErrors(std::move(Err), llvm::errs(), "warning: "); +} + Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers, SymtabWritingMode WriteSymtab, object::Archive::Kind Kind, bool Deterministic, bool Thin, std::unique_ptr<MemoryBuffer> OldArchiveBuf, - std::optional<bool> IsEC) { + std::optional<bool> IsEC, + function_ref<void(Error)> Warn) { Expected<sys::fs::TempFile> Temp = sys::fs::TempFile::create(ArcName + ".temp-archive-%%%%%%%.a"); if (!Temp) @@ -1277,7 +1314,7 @@ Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers, raw_fd_ostream Out(Temp->FD, false); if (Error E = writeArchiveToStream(Out, NewMembers, WriteSymtab, Kind, - Deterministic, Thin, IsEC)) { + Deterministic, Thin, IsEC, Warn)) { if (Error DiscardError = Temp->discard()) return joinErrors(std::move(E), std::move(DiscardError)); return E; @@ -1301,12 +1338,14 @@ Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers, Expected<std::unique_ptr<MemoryBuffer>> writeArchiveToBuffer(ArrayRef<NewArchiveMember> NewMembers, SymtabWritingMode WriteSymtab, object::Archive::Kind Kind, - bool Deterministic, bool Thin) { + bool Deterministic, bool Thin, + function_ref<void(Error)> Warn) { SmallVector<char, 0> ArchiveBufferVector; raw_svector_ostream ArchiveStream(ArchiveBufferVector); - if (Error E = writeArchiveToStream(ArchiveStream, NewMembers, WriteSymtab, - Kind, Deterministic, Thin, std::nullopt)) + if (Error E = + writeArchiveToStream(ArchiveStream, NewMembers, WriteSymtab, Kind, + Deterministic, Thin, std::nullopt, Warn)) return std::move(E); return std::make_unique<SmallVectorMemoryBuffer>( |