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path: root/llvm/lib/InterfaceStub/ELFObjHandler.cpp
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-rw-r--r--llvm/lib/InterfaceStub/ELFObjHandler.cpp197
1 files changed, 1 insertions, 196 deletions
diff --git a/llvm/lib/InterfaceStub/ELFObjHandler.cpp b/llvm/lib/InterfaceStub/ELFObjHandler.cpp
index 76c637b..cc9a8743 100644
--- a/llvm/lib/InterfaceStub/ELFObjHandler.cpp
+++ b/llvm/lib/InterfaceStub/ELFObjHandler.cpp
@@ -8,14 +8,11 @@
#include "llvm/InterfaceStub/ELFObjHandler.h"
#include "llvm/InterfaceStub/ELFStub.h"
-#include "llvm/MC/StringTableBuilder.h"
#include "llvm/Object/Binary.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/ELFTypes.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
-#include "llvm/Support/FileOutputBuffer.h"
-#include "llvm/Support/MathExtras.h"
#include "llvm/Support/MemoryBuffer.h"
using llvm::MemoryBufferRef;
@@ -41,158 +38,6 @@ struct DynamicEntries {
Optional<uint64_t> GnuHash;
};
-/// This initializes an ELF file header with information specific to a binary
-/// dynamic shared object.
-/// Offsets, indexes, links, etc. for section and program headers are just
-/// zero-initialized as they will be updated elsewhere.
-///
-/// @param ElfHeader Target ELFT::Ehdr to populate.
-/// @param Machine Target architecture (e_machine from ELF specifications).
-template <class ELFT>
-static void initELFHeader(typename ELFT::Ehdr &ElfHeader, uint16_t Machine) {
- memset(&ElfHeader, 0, sizeof(ElfHeader));
- // ELF identification.
- ElfHeader.e_ident[EI_MAG0] = ElfMagic[EI_MAG0];
- ElfHeader.e_ident[EI_MAG1] = ElfMagic[EI_MAG1];
- ElfHeader.e_ident[EI_MAG2] = ElfMagic[EI_MAG2];
- ElfHeader.e_ident[EI_MAG3] = ElfMagic[EI_MAG3];
- ElfHeader.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32;
- bool IsLittleEndian = ELFT::TargetEndianness == support::little;
- ElfHeader.e_ident[EI_DATA] = IsLittleEndian ? ELFDATA2LSB : ELFDATA2MSB;
- ElfHeader.e_ident[EI_VERSION] = EV_CURRENT;
- ElfHeader.e_ident[EI_OSABI] = ELFOSABI_NONE;
-
- // Remainder of ELF header.
- ElfHeader.e_type = ET_DYN;
- ElfHeader.e_machine = Machine;
- ElfHeader.e_version = EV_CURRENT;
- ElfHeader.e_ehsize = sizeof(typename ELFT::Ehdr);
- ElfHeader.e_phentsize = sizeof(typename ELFT::Phdr);
- ElfHeader.e_shentsize = sizeof(typename ELFT::Shdr);
-}
-
-namespace {
-template <class ELFT> struct OutputSection {
- using Elf_Shdr = typename ELFT::Shdr;
- std::string Name;
- Elf_Shdr Shdr;
- uint64_t Addr;
- uint64_t Offset;
- uint64_t Size;
- uint64_t Align;
- uint32_t Index;
- bool NoBits = true;
-};
-
-template <class T, class ELFT>
-struct ContentSection : public OutputSection<ELFT> {
- T Content;
- ContentSection() { this->NoBits = false; }
-};
-
-// This class just wraps StringTableBuilder for the purpose of adding a
-// default constructor.
-class ELFStringTableBuilder : public StringTableBuilder {
-public:
- ELFStringTableBuilder() : StringTableBuilder(StringTableBuilder::ELF) {}
-};
-
-template <class ELFT> class ELFStubBuilder {
-public:
- using Elf_Ehdr = typename ELFT::Ehdr;
- using Elf_Shdr = typename ELFT::Shdr;
- using Elf_Phdr = typename ELFT::Phdr;
- using Elf_Sym = typename ELFT::Sym;
- using Elf_Addr = typename ELFT::Addr;
- using Elf_Dyn = typename ELFT::Dyn;
-
- ELFStubBuilder(const ELFStubBuilder &) = delete;
- ELFStubBuilder(ELFStubBuilder &&) = default;
-
- explicit ELFStubBuilder(const ELFStub &Stub) {
- // Populate string tables.
- ShStrTab.Name = ".shstrtab";
- ShStrTab.Align = 1;
- DynStr.Name = ".dynstr";
- DynStr.Align = 1;
- for (const ELFSymbol &Sym : Stub.Symbols)
- DynStr.Content.add(Sym.Name);
-
- std::vector<OutputSection<ELFT> *> Sections = {&DynStr, &ShStrTab};
- const OutputSection<ELFT> *LastSection = Sections.back();
- // Now set the Index and put sections names into ".shstrtab".
- uint64_t Index = 1;
- for (OutputSection<ELFT> *Sec : Sections) {
- Sec->Index = Index++;
- ShStrTab.Content.add(Sec->Name);
- }
- ShStrTab.Content.finalize();
- ShStrTab.Size = ShStrTab.Content.getSize();
- DynStr.Content.finalize();
- DynStr.Size = DynStr.Content.getSize();
- // Calculate sections' addresses and offsets.
- uint64_t CurrentOffset = sizeof(Elf_Ehdr);
- for (OutputSection<ELFT> *Sec : Sections) {
- Sec->Offset = alignTo(CurrentOffset, Sec->Align);
- Sec->Addr = Sec->Offset;
- CurrentOffset = Sec->Offset + Sec->Size;
- }
- // Write section headers of string tables.
- fillStrTabShdr(DynStr, SHF_ALLOC);
- fillStrTabShdr(ShStrTab);
- // Finish initializing the ELF header.
- initELFHeader<ELFT>(ElfHeader, Stub.Arch);
- ElfHeader.e_shstrndx = ShStrTab.Index;
- ElfHeader.e_shnum = LastSection->Index + 1;
- ElfHeader.e_shoff =
- alignTo(LastSection->Offset + LastSection->Size, sizeof(Elf_Addr));
- }
-
- size_t getSize() const {
- return ElfHeader.e_shoff + ElfHeader.e_shnum * sizeof(Elf_Shdr);
- }
-
- void write(uint8_t *Data) const {
- write(Data, ElfHeader);
- DynStr.Content.write(Data + DynStr.Shdr.sh_offset);
- ShStrTab.Content.write(Data + ShStrTab.Shdr.sh_offset);
- writeShdr(Data, DynStr);
- writeShdr(Data, ShStrTab);
- }
-
-private:
- Elf_Ehdr ElfHeader;
- ContentSection<ELFStringTableBuilder, ELFT> DynStr;
- ContentSection<ELFStringTableBuilder, ELFT> ShStrTab;
-
- template <class T> static void write(uint8_t *Data, const T &Value) {
- *reinterpret_cast<T *>(Data) = Value;
- }
-
- void fillStrTabShdr(ContentSection<ELFStringTableBuilder, ELFT> &StrTab,
- uint32_t ShFlags = 0) const {
- StrTab.Shdr.sh_type = SHT_STRTAB;
- StrTab.Shdr.sh_flags = ShFlags;
- StrTab.Shdr.sh_addr = StrTab.Addr;
- StrTab.Shdr.sh_offset = StrTab.Offset;
- StrTab.Shdr.sh_info = 0;
- StrTab.Shdr.sh_size = StrTab.Size;
- StrTab.Shdr.sh_name = ShStrTab.Content.getOffset(StrTab.Name);
- StrTab.Shdr.sh_addralign = StrTab.Align;
- StrTab.Shdr.sh_entsize = 0;
- StrTab.Shdr.sh_link = 0;
- }
-
- uint64_t shdrOffset(const OutputSection<ELFT> &Sec) const {
- return ElfHeader.e_shoff + Sec.Index * sizeof(Elf_Shdr);
- }
-
- void writeShdr(uint8_t *Data, const OutputSection<ELFT> &Sec) const {
- write(Data + shdrOffset(Sec), Sec.Shdr);
- }
-};
-} // end anonymous namespace
-
/// This function behaves similarly to StringRef::substr(), but attempts to
/// terminate the returned StringRef at the first null terminator. If no null
/// terminator is found, an error is returned.
@@ -519,32 +364,6 @@ buildStub(const ELFObjectFile<ELFT> &ElfObj) {
return std::move(DestStub);
}
-/// This function opens a file for writing and then writes a binary ELF stub to
-/// the file.
-///
-/// @param FilePath File path for writing the ELF binary.
-/// @param Stub Source ELFStub to generate a binary ELF stub from.
-template <class ELFT>
-static Error writeELFBinaryToFile(StringRef FilePath, const ELFStub &Stub) {
- ELFStubBuilder<ELFT> Builder{Stub};
- Expected<std::unique_ptr<FileOutputBuffer>> BufOrError =
- FileOutputBuffer::create(FilePath, Builder.getSize());
- if (!BufOrError)
- return createStringError(errc::invalid_argument,
- toString(BufOrError.takeError()) +
- " when trying to open `" + FilePath +
- "` for writing");
-
- // Write binary to file.
- std::unique_ptr<FileOutputBuffer> Buf = std::move(*BufOrError);
- Builder.write(Buf->getBufferStart());
-
- if (Error E = Buf->commit())
- return E;
-
- return Error::success();
-}
-
Expected<std::unique_ptr<ELFStub>> readELFFile(MemoryBufferRef Buf) {
Expected<std::unique_ptr<Binary>> BinOrErr = createBinary(Buf);
if (!BinOrErr) {
@@ -561,22 +380,8 @@ Expected<std::unique_ptr<ELFStub>> readELFFile(MemoryBufferRef Buf) {
} else if (auto Obj = dyn_cast<ELFObjectFile<ELF64BE>>(Bin)) {
return buildStub(*Obj);
}
- return createStringError(errc::not_supported, "unsupported binary format");
-}
-// This function wraps the ELFT writeELFBinaryToFile() so writeBinaryStub()
-// can be called without having to use ELFType templates directly.
-Error writeBinaryStub(StringRef FilePath, const ELFStub &Stub,
- ELFTarget OutputFormat) {
- if (OutputFormat == ELFTarget::ELF32LE)
- return writeELFBinaryToFile<ELF32LE>(FilePath, Stub);
- if (OutputFormat == ELFTarget::ELF32BE)
- return writeELFBinaryToFile<ELF32BE>(FilePath, Stub);
- if (OutputFormat == ELFTarget::ELF64LE)
- return writeELFBinaryToFile<ELF64LE>(FilePath, Stub);
- if (OutputFormat == ELFTarget::ELF64BE)
- return writeELFBinaryToFile<ELF64BE>(FilePath, Stub);
- llvm_unreachable("invalid binary output target");
+ return createStringError(errc::not_supported, "Unsupported binary format");
}
} // end namespace elfabi
generated by cgit v1.1 at 2025-10-06 14:28:10 +0000