[llvm] r309032 - Reland "[LLVM][llvm-objcopy] Added basic plumbing to get things started"
Petr Hosek via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 25 14:16:33 PDT 2017
Author: phosek
Date: Tue Jul 25 14:16:33 2017
New Revision: 309032
URL: http://llvm.org/viewvc/llvm-project?rev=309032&view=rev
Log:
Reland "[LLVM][llvm-objcopy] Added basic plumbing to get things started"
As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
Added:
llvm/trunk/test/tools/llvm-objcopy/basic-copy.test
llvm/trunk/test/tools/llvm-objcopy/empty-section.test
llvm/trunk/test/tools/llvm-objcopy/program-headers.test
llvm/trunk/tools/llvm-objcopy/CMakeLists.txt
llvm/trunk/tools/llvm-objcopy/LLVMBuild.txt
- copied, changed from r309030, llvm/trunk/tools/LLVMBuild.txt
llvm/trunk/tools/llvm-objcopy/Object.cpp
llvm/trunk/tools/llvm-objcopy/Object.h
llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
llvm/trunk/tools/llvm-objcopy/llvm-objcopy.h
Modified:
llvm/trunk/test/CMakeLists.txt
llvm/trunk/tools/LLVMBuild.txt
Modified: llvm/trunk/test/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CMakeLists.txt?rev=309032&r1=309031&r2=309032&view=diff
==============================================================================
--- llvm/trunk/test/CMakeLists.txt (original)
+++ llvm/trunk/test/CMakeLists.txt Tue Jul 25 14:16:33 2017
@@ -61,6 +61,7 @@ set(LLVM_TEST_DEPENDS
llvm-modextract
llvm-mt
llvm-nm
+ llvm-objcopy
llvm-objdump
llvm-opt-report
llvm-pdbutil
Added: llvm/trunk/test/tools/llvm-objcopy/basic-copy.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/basic-copy.test?rev=309032&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/basic-copy.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/basic-copy.test Tue Jul 25 14:16:33 2017
@@ -0,0 +1,47 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy %t %t2
+# RUN: llvm-readobj -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_EXEC
+ Machine: EM_X86_64
+Sections:
+ - Name: .bss
+ Type: SHT_NOBITS
+ Flags: [ SHF_ALLOC ]
+ AddressAlign: 0x0000000000000010
+ Size: 64
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ AddressAlign: 0x0000000000000010
+ Content: "00000000"
+
+# CHECK: Type: SHT_NULL
+
+# CHECK: Name: .bss
+# CHECK-NEXT: Type: SHT_NOBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address:
+# CHECK-NEXT: Offset: [[OFFSET:0x[0-9A-F]+]]
+# CHECK-NEXT: Size: 64
+
+# CHECK: Name: .text
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: SHF_EXECINSTR
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address:
+# CHECK-NEXT: Offset: [[OFFSET]]
+# CHECK-NEXT: Size: 4
+
+# CHECK: Name: .shstrtab
+# CHECK-NEXT: Type: SHT_STRTAB
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: ]
Added: llvm/trunk/test/tools/llvm-objcopy/empty-section.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/empty-section.test?rev=309032&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/empty-section.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/empty-section.test Tue Jul 25 14:16:33 2017
@@ -0,0 +1,55 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy %t %t2
+# RUN: llvm-readobj -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_EXEC
+ Machine: EM_X86_64
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Address: 0x0
+ AddressAlign: 0x0000000000001000
+ Content: "00000000"
+ - Name: .empty
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1000
+ AddressAlign: 0x0000000000001000
+ Content: ""
+ - Name: .data
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1000
+ AddressAlign: 0x0000000000001000
+ Content: "00000000"
+
+
+# CHECK: Name: .text
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: SHF_EXECINSTR
+# CHECK-NEXT: ]
+
+# CHECK: Name: .empty
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x1000
+# CHECK-NEXT: Offset: 0x2000
+# CHECK-NEXT: Size: 0
+
+# CHECK: Name: .data
+# CHECK-NEXT: Type: SHT_PROGBITS
+# CHECK-NEXT: Flags [
+# CHECK-NEXT: SHF_ALLOC
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0x1000
+# CHECK-NEXT: Offset: 0x2000
+# CHECK-NEXT: Size: 4
Added: llvm/trunk/test/tools/llvm-objcopy/program-headers.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/program-headers.test?rev=309032&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/program-headers.test (added)
+++ llvm/trunk/test/tools/llvm-objcopy/program-headers.test Tue Jul 25 14:16:33 2017
@@ -0,0 +1,68 @@
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-objcopy %t %t2
+# RUN: llvm-readobj -program-headers %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_EXEC
+ Machine: EM_X86_64
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ AddressAlign: 0x0000000000001000
+ Content: "00000000"
+ - Name: .init
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Content: "00000000"
+ AddressAlign: 0x0000000000000010
+ - Name: .data
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+ Content: "00000000"
+ AddressAlign: 0x0000000000001000
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0xAAAA1000
+ PAddr: 0xFFFF1000
+ Sections:
+ - Section: .text
+ - Section: .init
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0xAAAA2000
+ PAddr: 0xFFFF2000
+ Sections:
+ - Section: .data
+
+#CHECK: ProgramHeaders [
+#CHECK-NEXT: ProgramHeader {
+#CHECK-NEXT: Type: PT_LOAD
+#CHECK-NEXT: Offset: 0x1000
+#CHECK-NEXT: VirtualAddress: 0xAAAA1000
+#CHECK-NEXT: PhysicalAddress: 0xFFFF1000
+#CHECK-NEXT: FileSize: 20
+#CHECK-NEXT: MemSize: 20
+#CHECK-NEXT: Flags [
+#CHECK-NEXT: PF_R
+#CHECK-NEXT: PF_X
+#CHECK-NEXT: ]
+#CHECK-NEXT: Alignment: 4096
+#CHECK-NEXT: }
+#CHECK-NEXT: ProgramHeader {
+#CHECK-NEXT: Type: PT_LOAD
+#CHECK-NEXT: Offset: 0x2000
+#CHECK-NEXT: VirtualAddress: 0xAAAA2000
+#CHECK-NEXT: PhysicalAddress: 0xFFFF2000
+#CHECK-NEXT: FileSize: 4
+#CHECK-NEXT: MemSize: 4
+#CHECK-NEXT: Flags [
+#CHECK-NEXT: PF_R
+#CHECK-NEXT: ]
+#CHECK-NEXT: Alignment: 4096
+#CHECK-NEXT: }
+#CHECK-NEXT:]
Modified: llvm/trunk/tools/LLVMBuild.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/LLVMBuild.txt?rev=309032&r1=309031&r2=309032&view=diff
==============================================================================
--- llvm/trunk/tools/LLVMBuild.txt (original)
+++ llvm/trunk/tools/LLVMBuild.txt Tue Jul 25 14:16:33 2017
@@ -40,6 +40,7 @@ subdirectories =
llvm-modextract
llvm-mt
llvm-nm
+ llvm-objcopy
llvm-objdump
llvm-pdbutil
llvm-profdata
Added: llvm/trunk/tools/llvm-objcopy/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/CMakeLists.txt?rev=309032&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/CMakeLists.txt (added)
+++ llvm/trunk/tools/llvm-objcopy/CMakeLists.txt Tue Jul 25 14:16:33 2017
@@ -0,0 +1,9 @@
+set(LLVM_LINK_COMPONENTS
+ Object
+ Support
+ MC
+ )
+add_llvm_tool(llvm-objcopy
+ llvm-objcopy.cpp
+ Object.cpp
+ )
Copied: llvm/trunk/tools/llvm-objcopy/LLVMBuild.txt (from r309030, llvm/trunk/tools/LLVMBuild.txt)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/LLVMBuild.txt?p2=llvm/trunk/tools/llvm-objcopy/LLVMBuild.txt&p1=llvm/trunk/tools/LLVMBuild.txt&r1=309030&r2=309032&rev=309032&view=diff
==============================================================================
--- llvm/trunk/tools/LLVMBuild.txt (original)
+++ llvm/trunk/tools/llvm-objcopy/LLVMBuild.txt Tue Jul 25 14:16:33 2017
@@ -1,4 +1,4 @@
-;===- ./tools/LLVMBuild.txt ------------------------------------*- Conf -*--===;
+;===- ./tools/llvm-objcopy/LLVMBuild.txt -----------------------*- Conf -*--===;
;
; The LLVM Compiler Infrastructure
;
@@ -14,43 +14,8 @@
; http://llvm.org/docs/LLVMBuild.html
;
;===------------------------------------------------------------------------===;
-
-[common]
-subdirectories =
- bugpoint
- dsymutil
- llc
- lli
- llvm-ar
- llvm-as
- llvm-bcanalyzer
- llvm-cat
- llvm-cov
- llvm-cvtres
- llvm-diff
- llvm-dis
- llvm-dwarfdump
- llvm-dwp
- llvm-extract
- llvm-jitlistener
- llvm-link
- llvm-lto
- llvm-mc
- llvm-mcmarkup
- llvm-modextract
- llvm-mt
- llvm-nm
- llvm-objdump
- llvm-pdbutil
- llvm-profdata
- llvm-rc
- llvm-rtdyld
- llvm-size
- llvm-split
- opt
- verify-uselistorder
-
[component_0]
-type = Group
-name = Tools
-parent = $ROOT
+type = Tool
+name = llvm-objcopy
+parent = Tools
+required_libraries = Object MC
Added: llvm/trunk/tools/llvm-objcopy/Object.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/Object.cpp?rev=309032&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/Object.cpp (added)
+++ llvm/trunk/tools/llvm-objcopy/Object.cpp Tue Jul 25 14:16:33 2017
@@ -0,0 +1,341 @@
+//===- Object.cpp -----------------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "Object.h"
+#include "llvm-objcopy.h"
+
+using namespace llvm;
+using namespace object;
+using namespace ELF;
+
+template <class ELFT> void Segment::writeHeader(FileOutputBuffer &Out) const {
+ typedef typename ELFT::Ehdr Elf_Ehdr;
+ typedef typename ELFT::Phdr Elf_Phdr;
+
+ uint8_t *Buf = Out.getBufferStart();
+ Buf += sizeof(Elf_Ehdr) + Index * sizeof(Elf_Phdr);
+ Elf_Phdr &Phdr = *reinterpret_cast<Elf_Phdr *>(Buf);
+ Phdr.p_type = Type;
+ Phdr.p_flags = Flags;
+ Phdr.p_offset = Offset;
+ Phdr.p_vaddr = VAddr;
+ Phdr.p_paddr = PAddr;
+ Phdr.p_filesz = FileSize;
+ Phdr.p_memsz = MemSize;
+ Phdr.p_align = Align;
+}
+
+void Segment::finalize() {
+ auto FirstSec = firstSection();
+ if (FirstSec) {
+ // It is possible for a gap to be at the begining of a segment. Because of
+ // this we need to compute the new offset based on how large this gap was
+ // in the source file. Section layout should have already ensured that this
+ // space is not used for something else.
+ uint64_t OriginalOffset = Offset;
+ Offset = FirstSec->Offset - (FirstSec->OriginalOffset - OriginalOffset);
+ }
+}
+
+void SectionBase::finalize() {}
+
+template <class ELFT>
+void SectionBase::writeHeader(FileOutputBuffer &Out) const {
+ uint8_t *Buf = Out.getBufferStart();
+ Buf += HeaderOffset;
+ typename ELFT::Shdr &Shdr = *reinterpret_cast<typename ELFT::Shdr *>(Buf);
+ Shdr.sh_name = NameIndex;
+ Shdr.sh_type = Type;
+ Shdr.sh_flags = Flags;
+ Shdr.sh_addr = Addr;
+ Shdr.sh_offset = Offset;
+ Shdr.sh_size = Size;
+ Shdr.sh_link = Link;
+ Shdr.sh_info = Info;
+ Shdr.sh_addralign = Align;
+ Shdr.sh_entsize = EntrySize;
+}
+
+void Section::writeSection(FileOutputBuffer &Out) const {
+ if (Type == SHT_NOBITS)
+ return;
+ uint8_t *Buf = Out.getBufferStart() + Offset;
+ std::copy(std::begin(Contents), std::end(Contents), Buf);
+}
+
+void StringTableSection::addString(StringRef Name) {
+ StrTabBuilder.add(Name);
+ Size = StrTabBuilder.getSize();
+}
+
+uint32_t StringTableSection::findIndex(StringRef Name) const {
+ return StrTabBuilder.getOffset(Name);
+}
+
+void StringTableSection::finalize() { StrTabBuilder.finalize(); }
+
+void StringTableSection::writeSection(FileOutputBuffer &Out) const {
+ StrTabBuilder.write(Out.getBufferStart() + Offset);
+}
+
+// Returns true IFF a section is wholly inside the range of a segment
+static bool sectionWithinSegment(const SectionBase &Section,
+ const Segment &Segment) {
+ // If a section is empty it should be treated like it has a size of 1. This is
+ // to clarify the case when an empty section lies on a boundary between two
+ // segments and ensures that the section "belongs" to the second segment and
+ // not the first.
+ uint64_t SecSize = Section.Size ? Section.Size : 1;
+ return Segment.Offset <= Section.OriginalOffset &&
+ Segment.Offset + Segment.FileSize >= Section.OriginalOffset + SecSize;
+}
+
+template <class ELFT>
+void Object<ELFT>::readProgramHeaders(const ELFFile<ELFT> &ElfFile) {
+ uint32_t Index = 0;
+ for (const auto &Phdr : unwrapOrError(ElfFile.program_headers())) {
+ Segments.emplace_back(make_unique<Segment>());
+ Segment &Seg = *Segments.back();
+ Seg.Type = Phdr.p_type;
+ Seg.Flags = Phdr.p_flags;
+ Seg.Offset = Phdr.p_offset;
+ Seg.VAddr = Phdr.p_vaddr;
+ Seg.PAddr = Phdr.p_paddr;
+ Seg.FileSize = Phdr.p_filesz;
+ Seg.MemSize = Phdr.p_memsz;
+ Seg.Align = Phdr.p_align;
+ Seg.Index = Index++;
+ for (auto &Section : Sections) {
+ if (sectionWithinSegment(*Section, Seg)) {
+ Seg.addSection(&*Section);
+ if (!Section->ParentSegment ||
+ Section->ParentSegment->Offset > Seg.Offset) {
+ Section->ParentSegment = &Seg;
+ }
+ }
+ }
+ }
+}
+
+template <class ELFT>
+std::unique_ptr<SectionBase>
+Object<ELFT>::makeSection(const llvm::object::ELFFile<ELFT> &ElfFile,
+ const Elf_Shdr &Shdr) {
+ ArrayRef<uint8_t> Data;
+ switch (Shdr.sh_type) {
+ case SHT_STRTAB:
+ return make_unique<StringTableSection>();
+ case SHT_NOBITS:
+ return make_unique<Section>(Data);
+ default:
+ Data = unwrapOrError(ElfFile.getSectionContents(&Shdr));
+ return make_unique<Section>(Data);
+ };
+}
+
+template <class ELFT>
+void Object<ELFT>::readSectionHeaders(const ELFFile<ELFT> &ElfFile) {
+ uint32_t Index = 0;
+ for (const auto &Shdr : unwrapOrError(ElfFile.sections())) {
+ if (Index == 0) {
+ ++Index;
+ continue;
+ }
+ SecPtr Sec = makeSection(ElfFile, Shdr);
+ Sec->Name = unwrapOrError(ElfFile.getSectionName(&Shdr));
+ Sec->Type = Shdr.sh_type;
+ Sec->Flags = Shdr.sh_flags;
+ Sec->Addr = Shdr.sh_addr;
+ Sec->Offset = Shdr.sh_offset;
+ Sec->OriginalOffset = Shdr.sh_offset;
+ Sec->Size = Shdr.sh_size;
+ Sec->Link = Shdr.sh_link;
+ Sec->Info = Shdr.sh_info;
+ Sec->Align = Shdr.sh_addralign;
+ Sec->EntrySize = Shdr.sh_entsize;
+ Sec->Index = Index++;
+ Sections.push_back(std::move(Sec));
+ }
+}
+
+template <class ELFT> size_t Object<ELFT>::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.
+ return SHOffset + Sections.size() * sizeof(Elf_Shdr) + sizeof(Elf_Shdr);
+}
+
+template <class ELFT> Object<ELFT>::Object(const ELFObjectFile<ELFT> &Obj) {
+ const auto &ElfFile = *Obj.getELFFile();
+ const auto &Ehdr = *ElfFile.getHeader();
+
+ std::copy(Ehdr.e_ident, Ehdr.e_ident + 16, Ident);
+ Type = Ehdr.e_type;
+ Machine = Ehdr.e_machine;
+ Version = Ehdr.e_version;
+ Entry = Ehdr.e_entry;
+ Flags = Ehdr.e_flags;
+
+ readSectionHeaders(ElfFile);
+ readProgramHeaders(ElfFile);
+
+ SectionNames =
+ dyn_cast<StringTableSection>(Sections[Ehdr.e_shstrndx - 1].get());
+}
+
+template <class ELFT> void Object<ELFT>::sortSections() {
+ // Put all sections in offset order. Maintain the ordering as closely as
+ // possible while meeting that demand however.
+ auto CompareSections = [](const SecPtr &A, const SecPtr &B) {
+ return A->OriginalOffset < B->OriginalOffset;
+ };
+ std::stable_sort(std::begin(Sections), std::end(Sections), CompareSections);
+}
+
+template <class ELFT> void Object<ELFT>::assignOffsets() {
+ // Decide file offsets and indexes.
+ size_t PhdrSize = Segments.size() * sizeof(Elf_Phdr);
+ // We can put section data after the ELF header and the program headers.
+ uint64_t Offset = sizeof(Elf_Ehdr) + PhdrSize;
+ uint64_t Index = 1;
+ for (auto &Section : Sections) {
+ // The segment can have a different alignment than the section. In the case
+ // that there is a parent segment then as long as we satisfy the alignment
+ // of the segment it should follow that that the section is aligned.
+ if (Section->ParentSegment) {
+ auto FirstInSeg = Section->ParentSegment->firstSection();
+ if (FirstInSeg == Section.get()) {
+ Offset = alignTo(Offset, Section->ParentSegment->Align);
+ // There can be gaps at the start of a segment before the first section.
+ // So first we assign the alignment of the segment and then assign the
+ // location of the section from there
+ Section->Offset =
+ Offset + Section->OriginalOffset - Section->ParentSegment->Offset;
+ }
+ // We should respect interstitial gaps of allocated sections. We *must*
+ // maintain the memory image so that addresses are preserved. As, with the
+ // exception of SHT_NOBITS sections at the end of segments, the memory
+ // image is a copy of the file image, we preserve the file image as well.
+ // There's a strange case where a thread local SHT_NOBITS can cause the
+ // memory image and file image to not be the same. This occurs, on some
+ // systems, when a thread local SHT_NOBITS is between two SHT_PROGBITS
+ // and the thread local SHT_NOBITS section is at the end of a TLS segment.
+ // In this case to faithfully copy the segment file image we must use
+ // relative offsets. In any other case this would be the same as using the
+ // relative addresses so this should maintian the memory image as desired.
+ Offset = FirstInSeg->Offset + Section->OriginalOffset -
+ FirstInSeg->OriginalOffset;
+ }
+ // Alignment should have already been handled by the above if statement if
+ // this if this section is in a segment. Technically this shouldn't do
+ // anything bad if the alignments of the sections are all correct and the
+ // file image isn't corrupted. Still in sticking with the motto "maintain
+ // the file image" we should avoid messing up the file image if the
+ // alignment disagrees with the file image.
+ if (!Section->ParentSegment && Section->Align)
+ Offset = alignTo(Offset, Section->Align);
+ Section->Offset = Offset;
+ Section->Index = Index++;
+ if (Section->Type != SHT_NOBITS)
+ Offset += Section->Size;
+ }
+ // 'offset' should now be just after all the section data so we should set the
+ // section header table offset to be exactly here. This spot might not be
+ // aligned properly however so we should align it as needed. For 32-bit ELF
+ // this needs to be 4-byte aligned and on 64-bit it needs to be 8-byte aligned
+ // so the size of ELFT::Addr is used to ensure this.
+ Offset = alignTo(Offset, sizeof(typename ELFT::Addr));
+ SHOffset = Offset;
+}
+
+template <class ELFT> void Object<ELFT>::finalize() {
+ for (auto &Section : Sections)
+ SectionNames->addString(Section->Name);
+
+ sortSections();
+ assignOffsets();
+
+ // Finalize SectionNames first so that we can assign name indexes.
+ SectionNames->finalize();
+ // Finally now that all offsets and indexes have been set we can finalize any
+ // remaining issues.
+ uint64_t Offset = SHOffset + sizeof(Elf_Shdr);
+ for (auto &Section : Sections) {
+ Section->HeaderOffset = Offset;
+ Offset += sizeof(Elf_Shdr);
+ Section->NameIndex = SectionNames->findIndex(Section->Name);
+ Section->finalize();
+ }
+
+ for (auto &Segment : Segments)
+ Segment->finalize();
+}
+
+template <class ELFT>
+void Object<ELFT>::writeHeader(FileOutputBuffer &Out) const {
+ uint8_t *Buf = Out.getBufferStart();
+ Elf_Ehdr &Ehdr = *reinterpret_cast<Elf_Ehdr *>(Buf);
+ std::copy(Ident, Ident + 16, Ehdr.e_ident);
+ Ehdr.e_type = Type;
+ Ehdr.e_machine = Machine;
+ Ehdr.e_version = Version;
+ Ehdr.e_entry = Entry;
+ Ehdr.e_phoff = sizeof(Elf_Ehdr);
+ Ehdr.e_shoff = SHOffset;
+ Ehdr.e_flags = Flags;
+ Ehdr.e_ehsize = sizeof(Elf_Ehdr);
+ Ehdr.e_phentsize = sizeof(Elf_Phdr);
+ Ehdr.e_phnum = Segments.size();
+ Ehdr.e_shentsize = sizeof(Elf_Shdr);
+ Ehdr.e_shnum = Sections.size() + 1;
+ Ehdr.e_shstrndx = SectionNames->Index;
+}
+
+template <class ELFT>
+void Object<ELFT>::writeProgramHeaders(FileOutputBuffer &Out) const {
+ for (auto &Phdr : Segments)
+ Phdr->template writeHeader<ELFT>(Out);
+}
+
+template <class ELFT>
+void Object<ELFT>::writeSectionHeaders(FileOutputBuffer &Out) const {
+ uint8_t *Buf = Out.getBufferStart() + SHOffset;
+ // This reference serves to write the dummy section header at the begining
+ // of the file.
+ Elf_Shdr &Shdr = *reinterpret_cast<Elf_Shdr *>(Buf);
+ Shdr.sh_name = 0;
+ Shdr.sh_type = SHT_NULL;
+ Shdr.sh_flags = 0;
+ Shdr.sh_addr = 0;
+ Shdr.sh_offset = 0;
+ Shdr.sh_size = 0;
+ Shdr.sh_link = 0;
+ Shdr.sh_info = 0;
+ Shdr.sh_addralign = 0;
+ Shdr.sh_entsize = 0;
+
+ for (auto &Section : Sections)
+ Section->template writeHeader<ELFT>(Out);
+}
+
+template <class ELFT>
+void Object<ELFT>::writeSectionData(FileOutputBuffer &Out) const {
+ for (auto &Section : Sections)
+ Section->writeSection(Out);
+}
+
+template <class ELFT> void Object<ELFT>::write(FileOutputBuffer &Out) {
+ writeHeader(Out);
+ writeProgramHeaders(Out);
+ writeSectionData(Out);
+ writeSectionHeaders(Out);
+}
+
+template class Object<ELF64LE>;
+template class Object<ELF64BE>;
+template class Object<ELF32LE>;
+template class Object<ELF32BE>;
Added: llvm/trunk/tools/llvm-objcopy/Object.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/Object.h?rev=309032&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/Object.h (added)
+++ llvm/trunk/tools/llvm-objcopy/Object.h Tue Jul 25 14:16:33 2017
@@ -0,0 +1,150 @@
+//===- Object.h -------------------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_OBJCOPY_OBJECT_H
+#define LLVM_OBJCOPY_OBJECT_H
+
+#include "llvm/MC/StringTableBuilder.h"
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Support/FileOutputBuffer.h"
+
+#include <memory>
+#include <set>
+
+class Segment;
+
+class SectionBase {
+public:
+ llvm::StringRef Name;
+ Segment *ParentSegment = nullptr;
+ uint64_t HeaderOffset;
+ uint64_t OriginalOffset;
+ uint32_t Index;
+
+ uint64_t Addr = 0;
+ uint64_t Align = 1;
+ uint32_t EntrySize = 0;
+ uint64_t Flags = 0;
+ uint64_t Info = 0;
+ uint64_t Link = llvm::ELF::SHN_UNDEF;
+ uint64_t NameIndex = 0;
+ uint64_t Offset = 0;
+ uint64_t Size = 0;
+ uint64_t Type = llvm::ELF::SHT_NULL;
+
+ virtual ~SectionBase() {}
+ virtual void finalize();
+ template <class ELFT> void writeHeader(llvm::FileOutputBuffer &Out) const;
+ virtual void writeSection(llvm::FileOutputBuffer &Out) const = 0;
+};
+
+class Segment {
+private:
+ struct SectionCompare {
+ bool operator()(const SectionBase *Lhs, const SectionBase *Rhs) const {
+ // Some sections might have the same address if one of them is empty. To
+ // fix this we can use the lexicographic ordering on ->Addr and the
+ // address of the actully stored section.
+ if (Lhs->Addr == Rhs->Addr)
+ return Lhs < Rhs;
+ return Lhs->Addr < Rhs->Addr;
+ }
+ };
+
+ std::set<const SectionBase *, SectionCompare> Sections;
+
+public:
+ uint64_t Align;
+ uint64_t FileSize;
+ uint32_t Flags;
+ uint32_t Index;
+ uint64_t MemSize;
+ uint64_t Offset;
+ uint64_t PAddr;
+ uint64_t Type;
+ uint64_t VAddr;
+
+ void finalize();
+ const SectionBase *firstSection() const {
+ if (!Sections.empty())
+ return *Sections.begin();
+ return nullptr;
+ }
+ void addSection(const SectionBase *sec) { Sections.insert(sec); }
+ template <class ELFT> void writeHeader(llvm::FileOutputBuffer &Out) const;
+};
+
+class Section : public SectionBase {
+private:
+ llvm::ArrayRef<uint8_t> Contents;
+
+public:
+ Section(llvm::ArrayRef<uint8_t> Data) : Contents(Data) {}
+ void writeSection(llvm::FileOutputBuffer &Out) const override;
+};
+
+// This is just a wraper around a StringTableBuilder that implements SectionBase
+class StringTableSection : public SectionBase {
+private:
+ llvm::StringTableBuilder StrTabBuilder;
+
+public:
+ StringTableSection() : StrTabBuilder(llvm::StringTableBuilder::ELF) {
+ Type = llvm::ELF::SHT_STRTAB;
+ }
+
+ void addString(llvm::StringRef Name);
+ uint32_t findIndex(llvm::StringRef Name) const;
+ void finalize() override;
+ void writeSection(llvm::FileOutputBuffer &Out) const override;
+ static bool classof(const SectionBase *S) {
+ return S->Type == llvm::ELF::SHT_STRTAB;
+ }
+};
+
+template <class ELFT> class Object {
+private:
+ typedef std::unique_ptr<SectionBase> SecPtr;
+ typedef std::unique_ptr<Segment> SegPtr;
+
+ typedef typename ELFT::Shdr Elf_Shdr;
+ typedef typename ELFT::Ehdr Elf_Ehdr;
+ typedef typename ELFT::Phdr Elf_Phdr;
+
+ StringTableSection *SectionNames;
+ std::vector<SecPtr> Sections;
+ std::vector<SegPtr> Segments;
+
+ void sortSections();
+ void assignOffsets();
+ SecPtr makeSection(const llvm::object::ELFFile<ELFT> &ElfFile,
+ const Elf_Shdr &Shdr);
+ void readProgramHeaders(const llvm::object::ELFFile<ELFT> &ElfFile);
+ void readSectionHeaders(const llvm::object::ELFFile<ELFT> &ElfFile);
+ void writeHeader(llvm::FileOutputBuffer &Out) const;
+ void writeProgramHeaders(llvm::FileOutputBuffer &Out) const;
+ void writeSectionData(llvm::FileOutputBuffer &Out) const;
+ void writeSectionHeaders(llvm::FileOutputBuffer &Out) const;
+
+public:
+ uint8_t Ident[16];
+ uint64_t Entry;
+ uint64_t SHOffset;
+ uint32_t Type;
+ uint32_t Machine;
+ uint32_t Version;
+ uint32_t Flags;
+
+ Object(const llvm::object::ELFObjectFile<ELFT> &Obj);
+ size_t totalSize() const;
+ void finalize();
+ void write(llvm::FileOutputBuffer &Out);
+};
+
+#endif
Added: llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp?rev=309032&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp (added)
+++ llvm/trunk/tools/llvm-objcopy/llvm-objcopy.cpp Tue Jul 25 14:16:33 2017
@@ -0,0 +1,99 @@
+//===- llvm-objcopy.cpp -----------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#include "llvm-objcopy.h"
+#include "Object.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/FileOutputBuffer.h"
+#include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/ToolOutputFile.h"
+
+#include <memory>
+#include <string>
+#include <system_error>
+
+using namespace llvm;
+using namespace object;
+using namespace ELF;
+
+// The name this program was invoked as.
+static StringRef ToolName;
+
+namespace llvm {
+
+LLVM_ATTRIBUTE_NORETURN void error(Twine Message) {
+ errs() << ToolName << ": " << Message << ".\n";
+ errs().flush();
+ exit(1);
+}
+
+LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, std::error_code EC) {
+ assert(EC);
+ errs() << ToolName << ": '" << File << "': " << EC.message() << ".\n";
+ exit(1);
+}
+
+LLVM_ATTRIBUTE_NORETURN void reportError(StringRef File, llvm::Error E) {
+ assert(E);
+ std::string Buf;
+ raw_string_ostream OS(Buf);
+ logAllUnhandledErrors(std::move(E), OS, "");
+ OS.flush();
+ errs() << ToolName << ": '" << File << "': " << Buf;
+ exit(1);
+}
+}
+
+cl::opt<std::string> InputFilename(cl::Positional, cl::desc("<input>"));
+cl::opt<std::string> OutputFilename(cl::Positional, cl::desc("<output>"),
+ cl::init("-"));
+
+void CopyBinary(const ELFObjectFile<ELF64LE> &ObjFile) {
+ std::unique_ptr<FileOutputBuffer> Buffer;
+ Object<ELF64LE> Obj{ObjFile};
+ Obj.finalize();
+ ErrorOr<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
+ FileOutputBuffer::create(OutputFilename, Obj.totalSize(),
+ FileOutputBuffer::F_executable);
+ if (BufferOrErr.getError())
+ error("failed to open " + OutputFilename);
+ else
+ Buffer = std::move(*BufferOrErr);
+ std::error_code EC;
+ std::unique_ptr<tool_output_file> Out =
+ make_unique<tool_output_file>(OutputFilename.data(), EC, sys::fs::F_None);
+ if (EC)
+ report_fatal_error(EC.message());
+ Obj.write(*Buffer);
+ if (auto EC = Buffer->commit())
+ reportError(OutputFilename, EC);
+ Out->keep();
+}
+
+int main(int argc, char **argv) {
+ // Print a stack trace if we signal out.
+ sys::PrintStackTraceOnErrorSignal(argv[0]);
+ PrettyStackTraceProgram X(argc, argv);
+ llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
+ cl::ParseCommandLineOptions(argc, argv, "llvm objcopy utility\n");
+ ToolName = argv[0];
+ if (InputFilename.empty()) {
+ cl::PrintHelpMessage();
+ return 2;
+ }
+ Expected<OwningBinary<Binary>> BinaryOrErr = createBinary(InputFilename);
+ if (!BinaryOrErr)
+ reportError(InputFilename, BinaryOrErr.takeError());
+ Binary &Binary = *BinaryOrErr.get().getBinary();
+ if (ELFObjectFile<ELF64LE> *o = dyn_cast<ELFObjectFile<ELF64LE>>(&Binary)) {
+ CopyBinary(*o);
+ return 0;
+ }
+ reportError(InputFilename, object_error::invalid_file_type);
+}
Added: llvm/trunk/tools/llvm-objcopy/llvm-objcopy.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/llvm-objcopy.h?rev=309032&view=auto
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/llvm-objcopy.h (added)
+++ llvm/trunk/tools/llvm-objcopy/llvm-objcopy.h Tue Jul 25 14:16:33 2017
@@ -0,0 +1,32 @@
+//===- llvm-objcopy.h -------------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_OBJCOPY_H
+#define LLVM_OBJCOPY_H
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/Error.h"
+
+namespace llvm {
+
+LLVM_ATTRIBUTE_NORETURN extern void error(Twine Message);
+
+// This is taken from llvm-readobj.
+// [see here](llvm/tools/llvm-readobj/llvm-readobj.h:38)
+template <class T> T unwrapOrError(Expected<T> EO) {
+ if (EO)
+ return *EO;
+ std::string Buf;
+ raw_string_ostream OS(Buf);
+ logAllUnhandledErrors(EO.takeError(), OS, "");
+ OS.flush();
+ error(Buf);
+}
+}
+
+#endif
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