Use the new StringTableBuilder in yaml2elf

http://reviews.llvm.org/D3574

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207694 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Hans Wennborg 2014-04-30 19:38:09 +00:00
parent 68438988f2
commit 14d1db9019
3 changed files with 35 additions and 53 deletions

View File

@ -66,11 +66,11 @@ Symbols:
# CHECK: }
# CHECK: Section {
# CHECK-NEXT: Index: 1
# CHECK-NEXT: Name: .text (1)
# CHECK-NEXT: Name: .text (16)
# CHECK: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 2
# CHECK-NEXT: Name: .rel.text (7)
# CHECK-NEXT: Name: .rel.text (1)
# CHECK-NEXT: Type: SHT_REL (0x9)
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
@ -84,7 +84,7 @@ Symbols:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 3
# CHECK-NEXT: Name: .rela.text (17)
# CHECK-NEXT: Name: .rela.text (11)
# CHECK-NEXT: Type: SHT_RELA (0x4)
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: ]
@ -98,11 +98,11 @@ Symbols:
# CHECK-NEXT: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 4
# CHECK-NEXT: Name: .symtab (28)
# CHECK-NEXT: Name: .symtab (40)
# CHECK: }
# CHECK-NEXT: Section {
# CHECK-NEXT: Index: 5
# CHECK-NEXT: Name: .strtab (36)
# CHECK-NEXT: Name: .strtab (32)
# CHECK: }
# CHECK: Relocations [
# CHECK-NEXT: Section (2) .rel.text {

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@ -35,14 +35,14 @@ Sections:
# CHECK-NEXT: )
#
# CHECK: Section {
# CHECK: Name: .symtab (7)
# CHECK: Name: .symtab (25)
# CHECK: Type: SHT_SYMTAB (0x2)
# CHECK: }
# CHECK: Section {
# CHECK: Name: .strtab (15)
# CHECK: Name: .strtab (17)
# CHECK: Type: SHT_STRTAB (0x3)
# CHECK: }
# CHECK: Section {
# CHECK: Name: .shstrtab (23)
# CHECK: Name: .shstrtab (7)
# CHECK: Type: SHT_STRTAB (0x3)
# CHECK: }

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@ -16,6 +16,7 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Object/ELFObjectFile.h"
#include "llvm/Object/ELFYAML.h"
#include "llvm/Object/StringTableBuilder.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/YAMLTraits.h"
@ -23,45 +24,6 @@
using namespace llvm;
// There is similar code in yaml2coff, but with some slight COFF-specific
// variations like different initial state. Might be able to deduplicate
// some day, but also want to make sure that the Mach-O use case is served.
//
// This class has a deliberately small interface, since a lot of
// implementation variation is possible.
//
// TODO: Use the StringTable builder from lib/Object instead, since it
// will deduplicate suffixes.
namespace {
class StringTableBuilder {
/// \brief Indices of strings currently present in `Buf`.
StringMap<unsigned> StringIndices;
/// \brief The contents of the string table as we build it.
std::string Buf;
public:
StringTableBuilder() {
Buf.push_back('\0');
}
/// \returns Index of string in string table.
unsigned addString(StringRef S) {
StringMapEntry<unsigned> &Entry = StringIndices.GetOrCreateValue(S);
unsigned &I = Entry.getValue();
if (I != 0)
return I;
I = Buf.size();
Buf.append(S.begin(), S.end());
Buf.push_back('\0');
return I;
}
size_t size() const {
return Buf.size();
}
void writeToStream(raw_ostream &OS) {
OS.write(Buf.data(), Buf.size());
}
};
} // end anonymous namespace
// This class is used to build up a contiguous binary blob while keeping
// track of an offset in the output (which notionally begins at
// `InitialOffset`).
@ -226,9 +188,13 @@ bool ELFState<ELFT>::initSectionHeaders(std::vector<Elf_Shdr> &SHeaders,
zero(SHeader);
SHeaders.push_back(SHeader);
for (const auto &Sec : Doc.Sections)
DotShStrtab.add(Sec->Name);
DotShStrtab.finalize();
for (const auto &Sec : Doc.Sections) {
zero(SHeader);
SHeader.sh_name = DotShStrtab.addString(Sec->Name);
SHeader.sh_name = DotShStrtab.getOffset(Sec->Name);
SHeader.sh_type = Sec->Type;
SHeader.sh_flags = Sec->Flags;
SHeader.sh_addr = Sec->Address;
@ -273,7 +239,7 @@ template <class ELFT>
void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
ContiguousBlobAccumulator &CBA) {
zero(SHeader);
SHeader.sh_name = DotShStrtab.addString(StringRef(".symtab"));
SHeader.sh_name = DotShStrtab.getOffset(".symtab");
SHeader.sh_type = ELF::SHT_SYMTAB;
SHeader.sh_link = getDotStrTabSecNo();
// One greater than symbol table index of the last local symbol.
@ -287,6 +253,16 @@ void ELFState<ELFT>::initSymtabSectionHeader(Elf_Shdr &SHeader,
zero(Sym);
Syms.push_back(Sym);
}
// Add symbol names to .strtab.
for (const auto &Sym : Doc.Symbols.Local)
DotStrtab.add(Sym.Name);
for (const auto &Sym : Doc.Symbols.Global)
DotStrtab.add(Sym.Name);
for (const auto &Sym : Doc.Symbols.Weak)
DotStrtab.add(Sym.Name);
DotStrtab.finalize();
addSymbols(Doc.Symbols.Local, Syms, ELF::STB_LOCAL);
addSymbols(Doc.Symbols.Global, Syms, ELF::STB_GLOBAL);
addSymbols(Doc.Symbols.Weak, Syms, ELF::STB_WEAK);
@ -301,10 +277,10 @@ void ELFState<ELFT>::initStrtabSectionHeader(Elf_Shdr &SHeader, StringRef Name,
StringTableBuilder &STB,
ContiguousBlobAccumulator &CBA) {
zero(SHeader);
SHeader.sh_name = DotShStrtab.addString(Name);
SHeader.sh_name = DotShStrtab.getOffset(Name);
SHeader.sh_type = ELF::SHT_STRTAB;
STB.writeToStream(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
SHeader.sh_size = STB.size();
CBA.getOSAndAlignedOffset(SHeader.sh_offset) << STB.data();
SHeader.sh_size = STB.data().size();
SHeader.sh_addralign = 1;
}
@ -316,7 +292,7 @@ void ELFState<ELFT>::addSymbols(const std::vector<ELFYAML::Symbol> &Symbols,
Elf_Sym Symbol;
zero(Symbol);
if (!Sym.Name.empty())
Symbol.st_name = DotStrtab.addString(Sym.Name);
Symbol.st_name = DotStrtab.getOffset(Sym.Name);
Symbol.setBindingAndType(SymbolBinding, Sym.Type);
if (!Sym.Section.empty()) {
unsigned Index;
@ -445,6 +421,12 @@ int ELFState<ELFT>::writeELF(raw_ostream &OS, const ELFYAML::Object &Doc) {
Header.e_ehsize + Header.e_shentsize * Header.e_shnum;
ContiguousBlobAccumulator CBA(SectionContentBeginOffset);
// Doc might not contain .symtab, .strtab and .shstrtab sections,
// but we will emit them, so make sure to add them to ShStrTabSHeader.
State.DotShStrtab.add(".symtab");
State.DotShStrtab.add(".strtab");
State.DotShStrtab.add(".shstrtab");
std::vector<Elf_Shdr> SHeaders;
if(!State.initSectionHeaders(SHeaders, CBA))
return 1;