Index: llvm/trunk/test/tools/llvm-objcopy/ELF/copy-after-strip-sections.test =================================================================== --- llvm/trunk/test/tools/llvm-objcopy/ELF/copy-after-strip-sections.test +++ llvm/trunk/test/tools/llvm-objcopy/ELF/copy-after-strip-sections.test @@ -0,0 +1,26 @@ +# llvm-objcopy's --strip-sections removes the section headers. It should be +# possible to run the tool on the output after this operation. Performing any +# subsequent stripping operation, or copying the object, should produce +# identical output. + +# RUN: yaml2obj %s -o %t.in +# RUN: llvm-objcopy %t.in %t.stripped --strip-sections +# RUN: llvm-objcopy %t.stripped %t.stripped2 --strip-sections +# RUN: llvm-objcopy %t.stripped2 %t.out +# RUN: cmp %t.stripped %t.stripped2 +# RUN: cmp %t.stripped %t.out + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_EXEC + Machine: EM_X86_64 +Sections: + - Name: .text + Type: SHT_PROGBITS + Content: 'facefeed' +ProgramHeaders: + - Type: PT_LOAD + Sections: + - Section: .text Index: llvm/trunk/tools/llvm-objcopy/ELF/Object.h =================================================================== --- llvm/trunk/tools/llvm-objcopy/ELF/Object.h +++ llvm/trunk/tools/llvm-objcopy/ELF/Object.h @@ -226,12 +226,11 @@ public: virtual ~ELFWriter() {} - bool WriteSectionHeaders = true; + bool WriteSectionHeaders; Error finalize() override; Error write() override; - ELFWriter(Object &Obj, Buffer &Buf, bool WSH) - : Writer(Obj, Buf), WriteSectionHeaders(WSH) {} + ELFWriter(Object &Obj, Buffer &Buf, bool WSH); }; class BinaryWriter : public Writer { @@ -810,6 +809,7 @@ uint32_t Version; uint32_t Flags; + bool HadShdrs = true; StringTableSection *SectionNames = nullptr; SymbolTableSection *SymbolTable = nullptr; SectionIndexSection *SectionIndexTable = nullptr; Index: llvm/trunk/tools/llvm-objcopy/ELF/Object.cpp =================================================================== --- llvm/trunk/tools/llvm-objcopy/ELF/Object.cpp +++ llvm/trunk/tools/llvm-objcopy/ELF/Object.cpp @@ -1212,13 +1212,16 @@ if (ShstrIndex == SHN_XINDEX) ShstrIndex = unwrapOrError(ElfFile.getSection(0))->sh_link; - Obj.SectionNames = - Obj.sections().template getSectionOfType( - ShstrIndex, - "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) + - " in elf header " + " is invalid", - "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) + - " in elf header " + " is not a string table"); + if (ShstrIndex == SHN_UNDEF) + Obj.HadShdrs = false; + else + Obj.SectionNames = + Obj.sections().template getSectionOfType( + ShstrIndex, + "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) + + " in elf header is invalid", + "e_shstrndx field value " + Twine(Ehdr.e_shstrndx) + + " in elf header is not a string table"); } Writer::~Writer() {} @@ -1372,6 +1375,10 @@ } } +template +ELFWriter::ELFWriter(Object &Obj, Buffer &Buf, bool WSH) + : Writer(Obj, Buf), WriteSectionHeaders(WSH && Obj.HadShdrs) {} + Error Object::removeSections( std::function ToRemove) { @@ -1558,9 +1565,10 @@ template size_t ELFWriter::totalSize() const { // We already have the section header offset so we can calculate the total // size by just adding up the size of each section header. - auto NullSectionSize = WriteSectionHeaders ? sizeof(Elf_Shdr) : 0; - return Obj.SHOffset + Obj.sections().size() * sizeof(Elf_Shdr) + - NullSectionSize; + if (!WriteSectionHeaders) + return Obj.SHOffset; + size_t ShdrCount = Obj.sections().size() + 1; // Includes null shdr. + return Obj.SHOffset + ShdrCount * sizeof(Elf_Shdr); } template Error ELFWriter::write() {