[llvm] r316813 - Revert "Add support for writing 64-bit symbol tables for archives when offsets become too large for 32-bit"

Rafael Avila de Espindola via llvm-commits llvm-commits at lists.llvm.org
Fri Oct 27 17:03:59 PDT 2017


It is common practice to say in the commit message why something is
being reverted.

Cheers,
Rafael

Jake Ehrlich via llvm-commits <llvm-commits at lists.llvm.org> writes:

> Author: jakehehrlich
> Date: Fri Oct 27 16:39:31 2017
> New Revision: 316813
>
> URL: http://llvm.org/viewvc/llvm-project?rev=316813&view=rev
> Log:
> Revert "Add support for writing 64-bit symbol tables for archives when offsets become too large for 32-bit"
>
> This reverts commit r316805.
>
> Removed:
>     llvm/trunk/test/Object/archive-SYM64-write.test
> Modified:
>     llvm/trunk/lib/Object/ArchiveWriter.cpp
>
> Modified: llvm/trunk/lib/Object/ArchiveWriter.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/ArchiveWriter.cpp?rev=316813&r1=316812&r2=316813&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Object/ArchiveWriter.cpp (original)
> +++ llvm/trunk/lib/Object/ArchiveWriter.cpp Fri Oct 27 16:39:31 2017
> @@ -122,11 +122,11 @@ static void printWithSpacePadding(raw_os
>  static bool isBSDLike(object::Archive::Kind Kind) {
>    switch (Kind) {
>    case object::Archive::K_GNU:
> -  case object::Archive::K_GNU64:
>      return false;
>    case object::Archive::K_BSD:
>    case object::Archive::K_DARWIN:
>      return true;
> +  case object::Archive::K_GNU64:
>    case object::Archive::K_DARWIN64:
>    case object::Archive::K_COFF:
>      break;
> @@ -134,8 +134,8 @@ static bool isBSDLike(object::Archive::K
>    llvm_unreachable("not supported for writting");
>  }
>  
> -template <class T>
> -static void print(raw_ostream &Out, object::Archive::Kind Kind, T Val) {
> +static void print32(raw_ostream &Out, object::Archive::Kind Kind,
> +                    uint32_t Val) {
>    if (isBSDLike(Kind))
>      support::endian::Writer<support::little>(Out).write(Val);
>    else
> @@ -216,20 +216,6 @@ static std::string computeRelativePath(S
>    return Relative.str();
>  }
>  
> -static bool is64BitKind(object::Archive::Kind Kind) {
> -  switch (Kind) {
> -  case object::Archive::K_GNU:
> -  case object::Archive::K_BSD:
> -  case object::Archive::K_DARWIN:
> -  case object::Archive::K_COFF:
> -    return false;
> -  case object::Archive::K_DARWIN64:
> -  case object::Archive::K_GNU64:
> -    return true;
> -  }
> -  llvm_unreachable("not supported for writting");
> -}
> -
>  static void addToStringTable(raw_ostream &Out, StringRef ArcName,
>                               const NewArchiveMember &M, bool Thin) {
>    StringRef ID = M.Buf->getBufferIdentifier();
> @@ -302,14 +288,6 @@ static bool isArchiveSymbol(const object
>    return true;
>  }
>  
> -static void printNBits(raw_ostream &Out, object::Archive::Kind Kind,
> -                       uint64_t Val) {
> -  if (is64BitKind(Kind))
> -    print<uint64_t>(Out, Kind, Val);
> -  else
> -    print<uint32_t>(Out, Kind, Val);
> -}
> -
>  static void writeSymbolTable(raw_ostream &Out, object::Archive::Kind Kind,
>                               bool Deterministic, ArrayRef<MemberData> Members,
>                               StringRef StringTable) {
> @@ -321,11 +299,9 @@ static void writeSymbolTable(raw_ostream
>      NumSyms += M.Symbols.size();
>  
>    unsigned Size = 0;
> -  Size += is64BitKind(Kind) ? 8 : 4; // Number of entries
> +  Size += 4; // Number of entries
>    if (isBSDLike(Kind))
>      Size += NumSyms * 8; // Table
> -  else if (is64BitKind(Kind))
> -    Size += NumSyms * 8; // Table
>    else
>      Size += NumSyms * 4; // Table
>    if (isBSDLike(Kind))
> @@ -342,30 +318,27 @@ static void writeSymbolTable(raw_ostream
>    if (isBSDLike(Kind))
>      printBSDMemberHeader(Out, Out.tell(), "__.SYMDEF", now(Deterministic), 0, 0,
>                           0, Size);
> -  else if (is64BitKind(Kind))
> -    printGNUSmallMemberHeader(Out, "/SYM64", now(Deterministic), 0, 0, 0, Size);
>    else
>      printGNUSmallMemberHeader(Out, "", now(Deterministic), 0, 0, 0, Size);
>  
>    uint64_t Pos = Out.tell() + Size;
>  
>    if (isBSDLike(Kind))
> -    print<uint32_t>(Out, Kind, NumSyms * 8);
> +    print32(Out, Kind, NumSyms * 8);
>    else
> -    printNBits(Out, Kind, NumSyms);
> +    print32(Out, Kind, NumSyms);
>  
>    for (const MemberData &M : Members) {
>      for (unsigned StringOffset : M.Symbols) {
>        if (isBSDLike(Kind))
> -        print<uint32_t>(Out, Kind, StringOffset);
> -      printNBits(Out, Kind, Pos); // member offset
> +        print32(Out, Kind, StringOffset);
> +      print32(Out, Kind, Pos); // member offset
>      }
>      Pos += M.Header.size() + M.Data.size() + M.Padding.size();
>    }
>  
>    if (isBSDLike(Kind))
> -    // byte count of the string table
> -    print<uint32_t>(Out, Kind, StringTable.size());
> +    print32(Out, Kind, StringTable.size()); // byte count of the string table
>    Out << StringTable;
>  
>    while (Pad--)
> @@ -469,25 +442,6 @@ Error llvm::writeArchive(StringRef ArcNa
>    if (!StringTableBuf.empty())
>      Data.insert(Data.begin(), computeStringTable(StringTableBuf));
>  
> -  // We would like to detect if we need to switch to a 64-bit symbol table.
> -  if (WriteSymtab) {
> -    uint64_t MaxOffset = 0;
> -    uint64_t LastOffset = MaxOffset;
> -    for (const auto& M : Data) {
> -      // Record the start of the member's offset
> -      LastOffset = MaxOffset;
> -      // Account for the size of each part associated with the member.
> -      MaxOffset += M.Header.size() + M.Data.size() + M.Padding.size();
> -      // We assume 32-bit symbols to see if 32-bit symbols are possible or not.
> -      MaxOffset += M.Symbols.size() * 4;
> -    }
> -    // If LastOffset isn't going to fit in a 32-bit varible we need to switch
> -    // to 64-bit. Note that the file can be larger than 4GB as long as the last
> -    // member starts before the 4GB offset.
> -    if (LastOffset >> 32 != 0)
> -      Kind = object::Archive::K_GNU64;
> -  }
> -
>    SmallString<128> TmpArchive;
>    int TmpArchiveFD;
>    if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
>
> Removed: llvm/trunk/test/Object/archive-SYM64-write.test
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/archive-SYM64-write.test?rev=316812&view=auto
> ==============================================================================
> --- llvm/trunk/test/Object/archive-SYM64-write.test (original)
> +++ llvm/trunk/test/Object/archive-SYM64-write.test (removed)
> @@ -1,31 +0,0 @@
> -# RUN: yaml2obj %s > %t
> -# RUN: rm -f %t.lib
> -# RUN: cp %t %t2
> -# RUN: llvm-ar cr %t.lib %t %t2 %p/Inputs/trivial-object-test.elf-x86-64
> -# RUN: llvm-nm --print-armap %t.lib | FileCheck %s
> -
> -!ELF
> -FileHeader:
> -  Class:           ELFCLASS64
> -  Data:            ELFDATA2LSB
> -  Type:            ET_EXEC
> -  Machine:         EM_X86_64
> -Sections:
> -  - Name:            .data
> -    Type:            SHT_PROGBITS
> -    Flags:           [ SHF_ALLOC ]
> -    AddressAlign:    0x0000000000000001
> -    Content:         "00"
> -    Size:            2147483648
> -
> -# CHECK:      Archive map
> -# CHECK-NEXT: main in trivial-object-test.elf-x86-64
> -
> -# CHECK:    archive-SYM64-write.test.tmp:
> -
> -# CHECK:    archive-SYM64-write.test.tmp2:
> -
> -# CHECK:    trivial-object-test.elf-x86-64:
> -# CHECK-NEXT:                     U SomeOtherFunction
> -# CHECK-NEXT:    0000000000000000 T main
> -# CHECK-NEXT:                     U puts
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits


More information about the llvm-commits mailing list