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-rw-r--r--tools/yaml2obj/yaml2elf.cpp336
1 files changed, 171 insertions, 165 deletions
diff --git a/tools/yaml2obj/yaml2elf.cpp b/tools/yaml2obj/yaml2elf.cpp
index d46e154..21506d9 100644
--- a/tools/yaml2obj/yaml2elf.cpp
+++ b/tools/yaml2obj/yaml2elf.cpp
@@ -134,94 +134,125 @@ static void zero(T &Obj) {
memset(&Obj, 0, sizeof(Obj));
}
-/// \brief Create a string table in `SHeader`, which we assume is already
-/// zero'd.
-template <class Elf_Shdr>
-static void createStringTableSectionHeader(Elf_Shdr &SHeader,
- StringTableBuilder &STB,
- ContiguousBlobAccumulator &CBA) {
- SHeader.sh_type = ELF::SHT_STRTAB;
- STB.writeToStream(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
- SHeader.sh_size = STB.size();
- SHeader.sh_addralign = 1;
-}
-
namespace {
/// \brief "Single point of truth" for the ELF file construction.
/// TODO: This class still has a ways to go before it is truly a "single
/// point of truth".
template <class ELFT>
class ELFState {
+ typedef typename object::ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
+ typedef typename object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
+ typedef typename object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
+
/// \brief The future ".strtab" section.
StringTableBuilder DotStrtab;
- /// \brief The section number of the ".strtab" section.
- unsigned DotStrtabSecNo;
- /// \brief The accumulated contents of all sections so far.
- ContiguousBlobAccumulator &SectionContentAccum;
- typedef typename object::ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
- /// \brief The ELF file header.
- Elf_Ehdr &Header;
- SectionNameToIdxMap &SN2I;
+ /// \brief The future ".shstrtab" section.
+ StringTableBuilder DotShStrtab;
-public:
+ SectionNameToIdxMap SN2I;
+ const ELFYAML::Object &Doc;
+
+ bool buildSectionIndex();
+ void initELFHeader(Elf_Ehdr &Header);
+ bool initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
+ ContiguousBlobAccumulator &CBA);
+ void initSymtabSectionHeader(Elf_Shdr &SHeader,
+ ContiguousBlobAccumulator &CBA);
+ void initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
+ StringTableBuilder &STB,
+ ContiguousBlobAccumulator &CBA);
+ void addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
+ std::vector<Elf_Sym> &Syms, unsigned SymbolBinding);
+
+ // - SHT_NULL entry (placed first, i.e. 0'th entry)
+ // - symbol table (.symtab) (placed third to last)
+ // - string table (.strtab) (placed second to last)
+ // - section header string table (.shstrtab) (placed last)
+ unsigned getDotSymTabSecNo() const { return Doc.Sections.size() + 1; }
+ unsigned getDotStrTabSecNo() const { return Doc.Sections.size() + 2; }
+ unsigned getDotShStrTabSecNo() const { return Doc.Sections.size() + 3; }
+ unsigned getSectionCount() const { return Doc.Sections.size() + 4; }
- ELFState(Elf_Ehdr &Header_, ContiguousBlobAccumulator &Accum,
- unsigned DotStrtabSecNo_, SectionNameToIdxMap &SN2I_)
- : DotStrtab(), DotStrtabSecNo(DotStrtabSecNo_),
- SectionContentAccum(Accum), Header(Header_), SN2I(SN2I_) {}
+ ELFState(const ELFYAML::Object &D) : Doc(D) {}
- unsigned getDotStrTabSecNo() const { return DotStrtabSecNo; }
- StringTableBuilder &getStringTable() { return DotStrtab; }
- ContiguousBlobAccumulator &getSectionContentAccum() {
- return SectionContentAccum;
- }
- SectionNameToIdxMap &getSN2I() { return SN2I; }
+public:
+ static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc);
};
} // end anonymous namespace
-// FIXME: At this point it is fairly clear that we need to refactor these
-// static functions into methods of a class sharing some typedefs. These
-// ELF type names are insane.
template <class ELFT>
-static void
-addSymbols(const std::vector<ELFYAML::Symbol> &Symbols, ELFState<ELFT> &State,
- std::vector<typename object::ELFFile<ELFT>::Elf_Sym> &Syms,
- unsigned SymbolBinding) {
- typedef typename object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
- for (unsigned i = 0, e = Symbols.size(); i != e; ++i) {
- const ELFYAML::Symbol &Sym = Symbols[i];
- Elf_Sym Symbol;
- zero(Symbol);
- if (!Sym.Name.empty())
- Symbol.st_name = State.getStringTable().addString(Sym.Name);
- Symbol.setBindingAndType(SymbolBinding, Sym.Type);
- if (!Sym.Section.empty()) {
+void ELFState<ELFT>::initELFHeader(Elf_Ehdr &Header) {
+ using namespace llvm::ELF;
+ zero(Header);
+ Header.e_ident[EI_MAG0] = 0x7f;
+ Header.e_ident[EI_MAG1] = 'E';
+ Header.e_ident[EI_MAG2] = 'L';
+ Header.e_ident[EI_MAG3] = 'F';
+ Header.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32;
+ bool IsLittleEndian = ELFT::TargetEndianness == support::little;
+ Header.e_ident[EI_DATA] = IsLittleEndian ? ELFDATA2LSB : ELFDATA2MSB;
+ Header.e_ident[EI_VERSION] = EV_CURRENT;
+ Header.e_ident[EI_OSABI] = Doc.Header.OSABI;
+ Header.e_ident[EI_ABIVERSION] = 0;
+ Header.e_type = Doc.Header.Type;
+ Header.e_machine = Doc.Header.Machine;
+ Header.e_version = EV_CURRENT;
+ Header.e_entry = Doc.Header.Entry;
+ Header.e_flags = Doc.Header.Flags;
+ Header.e_ehsize = sizeof(Elf_Ehdr);
+ Header.e_shentsize = sizeof(Elf_Shdr);
+ // Immediately following the ELF header.
+ Header.e_shoff = sizeof(Header);
+ Header.e_shnum = getSectionCount();
+ Header.e_shstrndx = getDotShStrTabSecNo();
+}
+
+template <class ELFT>
+bool ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
+ ContiguousBlobAccumulator &CBA) {
+ // Ensure SHN_UNDEF entry is present. An all-zero section header is a
+ // valid SHN_UNDEF entry since SHT_NULL == 0.
+ Elf_Shdr SHeader;
+ zero(SHeader);
+ SHeaders.push_back(SHeader);
+
+ for (const auto &Sec : Doc.Sections) {
+ zero(SHeader);
+ SHeader.sh_name = DotShStrtab.addString(Sec.Name);
+ SHeader.sh_type = Sec.Type;
+ SHeader.sh_flags = Sec.Flags;
+ SHeader.sh_addr = Sec.Address;
+
+ Sec.Content.writeAsBinary(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
+ SHeader.sh_size = Sec.Content.binary_size();
+
+ if (!Sec.Link.empty()) {
unsigned Index;
- if (State.getSN2I().lookupSection(Sym.Section, Index)) {
- errs() << "error: Unknown section referenced: '" << Sym.Section
- << "' by YAML symbol " << Sym.Name << ".\n";
- exit(1);
+ if (SN2I.lookupSection(Sec.Link, Index)) {
+ errs() << "error: Unknown section referenced: '" << Sec.Link
+ << "' at YAML section '" << Sec.Name << "'.\n";
+ return false;;
}
- Symbol.st_shndx = Index;
- } // else Symbol.st_shndex == SHN_UNDEF (== 0), since it was zero'd earlier.
- Symbol.st_value = Sym.Value;
- Symbol.st_size = Sym.Size;
- Syms.push_back(Symbol);
+ SHeader.sh_link = Index;
+ }
+ SHeader.sh_info = 0;
+ SHeader.sh_addralign = Sec.AddressAlign;
+ SHeader.sh_entsize = 0;
+ SHeaders.push_back(SHeader);
}
+ return true;
}
template <class ELFT>
-static void
-handleSymtabSectionHeader(const ELFYAML::LocalGlobalWeakSymbols &Symbols,
- ELFState<ELFT> &State,
- typename object::ELFFile<ELFT>::Elf_Shdr &SHeader) {
-
- typedef typename object::ELFFile<ELFT>::Elf_Sym Elf_Sym;
+void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
+ ContiguousBlobAccumulator &CBA) {
+ zero(SHeader);
+ SHeader.sh_name = DotShStrtab.addString(StringRef(".symtab"));
SHeader.sh_type = ELF::SHT_SYMTAB;
- SHeader.sh_link = State.getDotStrTabSecNo();
+ SHeader.sh_link = getDotStrTabSecNo();
// One greater than symbol table index of the last local symbol.
- SHeader.sh_info = Symbols.Local.size() + 1;
+ SHeader.sh_info = Doc.Symbols.Local.size() + 1;
SHeader.sh_entsize = sizeof(Elf_Sym);
std::vector<Elf_Sym> Syms;
@@ -231,134 +262,109 @@ handleSymtabSectionHeader(const ELFYAML::LocalGlobalWeakSymbols &Symbols,
zero(Sym);
Syms.push_back(Sym);
}
- addSymbols(Symbols.Local, State, Syms, ELF::STB_LOCAL);
- addSymbols(Symbols.Global, State, Syms, ELF::STB_GLOBAL);
- addSymbols(Symbols.Weak, State, Syms, ELF::STB_WEAK);
+ addSymbols(Doc.Symbols.Local, Syms, ELF::STB_LOCAL);
+ addSymbols(Doc.Symbols.Global, Syms, ELF::STB_GLOBAL);
+ addSymbols(Doc.Symbols.Weak, Syms, ELF::STB_WEAK);
- ContiguousBlobAccumulator &CBA = State.getSectionContentAccum();
writeArrayData(CBA.getOSAndAlignedOffset(SHeader.sh_offset),
makeArrayRef(Syms));
SHeader.sh_size = arrayDataSize(makeArrayRef(Syms));
}
template <class ELFT>
-static int writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
- using namespace llvm::ELF;
- typedef typename object::ELFFile<ELFT>::Elf_Ehdr Elf_Ehdr;
- typedef typename object::ELFFile<ELFT>::Elf_Shdr Elf_Shdr;
-
- const ELFYAML::FileHeader &Hdr = Doc.Header;
-
- Elf_Ehdr Header;
- zero(Header);
- Header.e_ident[EI_MAG0] = 0x7f;
- Header.e_ident[EI_MAG1] = 'E';
- Header.e_ident[EI_MAG2] = 'L';
- Header.e_ident[EI_MAG3] = 'F';
- Header.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32;
- bool IsLittleEndian = ELFT::TargetEndianness == support::little;
- Header.e_ident[EI_DATA] = IsLittleEndian ? ELFDATA2LSB : ELFDATA2MSB;
- Header.e_ident[EI_VERSION] = EV_CURRENT;
- Header.e_ident[EI_OSABI] = Hdr.OSABI;
- Header.e_ident[EI_ABIVERSION] = 0;
- Header.e_type = Hdr.Type;
- Header.e_machine = Hdr.Machine;
- Header.e_version = EV_CURRENT;
- Header.e_entry = Hdr.Entry;
- Header.e_ehsize = sizeof(Elf_Ehdr);
+void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
+ StringTableBuilder &STB,
+ ContiguousBlobAccumulator &CBA) {
+ zero(SHeader);
+ SHeader.sh_name = DotShStrtab.addString(Name);
+ SHeader.sh_type = ELF::SHT_STRTAB;
+ STB.writeToStream(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
+ SHeader.sh_size = STB.size();
+ SHeader.sh_addralign = 1;
+}
- // TODO: Flesh out section header support.
- // TODO: Program headers.
+template <class ELFT>
+void ELFState<ELFT>::addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
+ std::vector<Elf_Sym> &Syms,
+ unsigned SymbolBinding) {
+ for (const auto &Sym : Symbols) {
+ Elf_Sym Symbol;
+ zero(Symbol);
+ if (!Sym.Name.empty())
+ Symbol.st_name = DotStrtab.addString(Sym.Name);
+ Symbol.setBindingAndType(SymbolBinding, Sym.Type);
+ if (!Sym.Section.empty()) {
+ unsigned Index;
+ if (SN2I.lookupSection(Sym.Section, Index)) {
+ errs() << "error: Unknown section referenced: '" << Sym.Section
+ << "' by YAML symbol " << Sym.Name << ".\n";
+ exit(1);
+ }
+ Symbol.st_shndx = Index;
+ } // else Symbol.st_shndex == SHN_UNDEF (== 0), since it was zero'd earlier.
+ Symbol.st_value = Sym.Value;
+ Symbol.st_size = Sym.Size;
+ Syms.push_back(Symbol);
+ }
+}
- Header.e_shentsize = sizeof(Elf_Shdr);
- // Immediately following the ELF header.
- Header.e_shoff = sizeof(Header);
- const std::vector<ELFYAML::Section> &Sections = Doc.Sections;
- // "+ 4" for
- // - SHT_NULL entry (placed first, i.e. 0'th entry)
- // - symbol table (.symtab) (placed third to last)
- // - string table (.strtab) (placed second to last)
- // - section header string table. (placed last)
- Header.e_shnum = Sections.size() + 4;
- // Place section header string table last.
- Header.e_shstrndx = Header.e_shnum - 1;
- const unsigned DotStrtabSecNo = Header.e_shnum - 2;
+template <class ELFT> bool ELFState<ELFT>::buildSectionIndex() {
+ SN2I.addName(".symtab", getDotSymTabSecNo());
+ SN2I.addName(".strtab", getDotStrTabSecNo());
+ SN2I.addName(".shstrtab", getDotShStrTabSecNo());
- // XXX: This offset is tightly coupled with the order that we write
- // things to `OS`.
- const size_t SectionContentBeginOffset =
- Header.e_ehsize + Header.e_shentsize * Header.e_shnum;
- ContiguousBlobAccumulator CBA(SectionContentBeginOffset);
- SectionNameToIdxMap SN2I;
- for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
- StringRef Name = Sections[i].Name;
+ for (unsigned i = 0, e = Doc.Sections.size(); i != e; ++i) {
+ StringRef Name = Doc.Sections[i].Name;
if (Name.empty())
continue;
// "+ 1" to take into account the SHT_NULL entry.
if (SN2I.addName(Name, i + 1)) {
errs() << "error: Repeated section name: '" << Name
<< "' at YAML section number " << i << ".\n";
- return 1;
+ return false;
}
}
+ return true;
+}
- ELFState<ELFT> State(Header, CBA, DotStrtabSecNo, SN2I);
+template <class ELFT>
+int ELFState<ELFT>::writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
+ ELFState<ELFT> State(Doc);
+ if (!State.buildSectionIndex())
+ return 1;
- StringTableBuilder SHStrTab;
- std::vector<Elf_Shdr> SHeaders;
- {
- // Ensure SHN_UNDEF entry is present. An all-zero section header is a
- // valid SHN_UNDEF entry since SHT_NULL == 0.
- Elf_Shdr SHdr;
- zero(SHdr);
- SHeaders.push_back(SHdr);
- }
- for (unsigned i = 0, e = Sections.size(); i != e; ++i) {
- const ELFYAML::Section &Sec = Sections[i];
- Elf_Shdr SHeader;
- zero(SHeader);
- SHeader.sh_name = SHStrTab.addString(Sec.Name);
- SHeader.sh_type = Sec.Type;
- SHeader.sh_flags = Sec.Flags;
- SHeader.sh_addr = Sec.Address;
+ Elf_Ehdr Header;
+ State.initELFHeader(Header);
- Sec.Content.writeAsBinary(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
- SHeader.sh_size = Sec.Content.binary_size();
+ // TODO: Flesh out section header support.
+ // TODO: Program headers.
- if (!Sec.Link.empty()) {
- unsigned Index;
- if (SN2I.lookupSection(Sec.Link, Index)) {
- errs() << "error: Unknown section referenced: '" << Sec.Link
- << "' at YAML section number " << i << ".\n";
- return 1;
- }
- SHeader.sh_link = Index;
- }
- SHeader.sh_info = 0;
- SHeader.sh_addralign = Sec.AddressAlign;
- SHeader.sh_entsize = 0;
- SHeaders.push_back(SHeader);
- }
+ // XXX: This offset is tightly coupled with the order that we write
+ // things to `OS`.
+ const size_t SectionContentBeginOffset =
+ Header.e_ehsize + Header.e_shentsize * Header.e_shnum;
+ ContiguousBlobAccumulator CBA(SectionContentBeginOffset);
+
+ std::vector<Elf_Shdr> SHeaders;
+ if(!State.initSectionHeaders(SHeaders, CBA))
+ return 1;
// .symtab section.
Elf_Shdr SymtabSHeader;
- zero(SymtabSHeader);
- SymtabSHeader.sh_name = SHStrTab.addString(StringRef(".symtab"));
- handleSymtabSectionHeader<ELFT>(Doc.Symbols, State, SymtabSHeader);
+ State.initSymtabSectionHeader(SymtabSHeader, CBA);
SHeaders.push_back(SymtabSHeader);
// .strtab string table header.
Elf_Shdr DotStrTabSHeader;
- zero(DotStrTabSHeader);
- DotStrTabSHeader.sh_name = SHStrTab.addString(StringRef(".strtab"));
- createStringTableSectionHeader(DotStrTabSHeader, State.getStringTable(), CBA);
+ State.initStrtabSectionHeader(DotStrTabSHeader, ".strtab", State.DotStrtab,
+ CBA);
SHeaders.push_back(DotStrTabSHeader);
- // Section header string table header.
- Elf_Shdr SHStrTabSHeader;
- zero(SHStrTabSHeader);
- createStringTableSectionHeader(SHStrTabSHeader, SHStrTab, CBA);
- SHeaders.push_back(SHStrTabSHeader);
+ // .shstrtab string table header.
+ Elf_Shdr ShStrTabSHeader;
+ State.initStrtabSectionHeader(ShStrTabSHeader, ".shstrtab", State.DotShStrtab,
+ CBA);
+ SHeaders.push_back(ShStrTabSHeader);
OS.write((const char *)&Header, sizeof(Header));
writeArrayData(OS, makeArrayRef(SHeaders));
@@ -389,13 +395,13 @@ int yaml2elf(llvm::raw_ostream &Out, llvm::MemoryBuffer *Buf) {
typedef ELFType<support::big, 4, false> BE32;
if (is64Bit(Doc)) {
if (isLittleEndian(Doc))
- return writeELF<LE64>(outs(), Doc);
+ return ELFState<LE64>::writeELF(outs(), Doc);
else
- return writeELF<BE64>(outs(), Doc);
+ return ELFState<BE64>::writeELF(outs(), Doc);
} else {
if (isLittleEndian(Doc))
- return writeELF<LE32>(outs(), Doc);
+ return ELFState<LE32>::writeELF(outs(), Doc);
else
- return writeELF<BE32>(outs(), Doc);
+ return ELFState<BE32>::writeELF(outs(), Doc);
}
}
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