[Object] Add {begin,end}_dynamic_symbols stubs and implementation for ELF.

Add -D option to llvm-nm to dump dynamic symbols.

Patch by David Meyer.

llvm-svn: 151600
This commit is contained in:
Michael J. Spencer 2012-02-28 00:40:37 +00:00
parent 248c29966c
commit 8c4729fd44
11 changed files with 168 additions and 23 deletions

View File

@ -152,6 +152,8 @@ public:
COFFObjectFile(MemoryBuffer *Object, error_code &ec);
virtual symbol_iterator begin_symbols() const;
virtual symbol_iterator end_symbols() const;
virtual symbol_iterator begin_dynamic_symbols() const;
virtual symbol_iterator end_dynamic_symbols() const;
virtual section_iterator begin_sections() const;
virtual section_iterator end_sections() const;

View File

@ -295,6 +295,7 @@ private:
const Elf_Shdr *SectionHeaderTable;
const Elf_Shdr *dot_shstrtab_sec; // Section header string table.
const Elf_Shdr *dot_strtab_sec; // Symbol header string table.
const Elf_Shdr *dot_dynstr_sec; // Dynamic symbol string table.
Sections_t SymbolTableSections;
IndexMap_t SymbolTableSectionsIndexMap;
DenseMap<const Elf_Sym*, ELF::Elf64_Word> ExtendedSymbolTable;
@ -319,7 +320,10 @@ private:
const Elf_Rela *getRela(DataRefImpl Rela) const;
const char *getString(uint32_t section, uint32_t offset) const;
const char *getString(const Elf_Shdr *section, uint32_t offset) const;
error_code getSymbolName(const Elf_Sym *Symb, StringRef &Res) const;
error_code getSymbolName(const Elf_Shdr *section,
const Elf_Sym *Symb,
StringRef &Res) const;
void VerifyStrTab(const Elf_Shdr *sh) const;
protected:
const Elf_Sym *getSymbol(DataRefImpl Symb) const; // FIXME: Should be private?
@ -375,6 +379,8 @@ public:
ELFObjectFile(MemoryBuffer *Object, error_code &ec);
virtual symbol_iterator begin_symbols() const;
virtual symbol_iterator end_symbols() const;
virtual symbol_iterator begin_dynamic_symbols() const;
virtual symbol_iterator end_dynamic_symbols() const;
virtual section_iterator begin_sections() const;
virtual section_iterator end_sections() const;
@ -425,10 +431,14 @@ error_code ELFObjectFile<target_endianness, is64Bits>
// Check to see if we are at the end of this symbol table.
if (Symb.d.a >= SymbolTableSection->getEntityCount()) {
// We are at the end. If there are other symbol tables, jump to them.
++Symb.d.b;
Symb.d.a = 1; // The 0th symbol in ELF is fake.
// If the symbol table is .dynsym, we are iterating dynamic symbols,
// and there is only one table of these.
if (Symb.d.b != 0) {
++Symb.d.b;
Symb.d.a = 1; // The 0th symbol in ELF is fake.
}
// Otherwise return the terminator.
if (Symb.d.b >= SymbolTableSections.size()) {
if (Symb.d.b == 0 || Symb.d.b >= SymbolTableSections.size()) {
Symb.d.a = std::numeric_limits<uint32_t>::max();
Symb.d.b = std::numeric_limits<uint32_t>::max();
}
@ -444,7 +454,7 @@ error_code ELFObjectFile<target_endianness, is64Bits>
StringRef &Result) const {
validateSymbol(Symb);
const Elf_Sym *symb = getSymbol(Symb);
return getSymbolName(symb, Result);
return getSymbolName(SymbolTableSections[Symb.d.b], symb, Result);
}
template<support::endianness target_endianness, bool is64Bits>
@ -1128,7 +1138,7 @@ error_code ELFObjectFile<target_endianness, is64Bits>
}
const Elf_Sym *symb = getEntry<Elf_Sym>(sec->sh_link, symbol_index);
StringRef symname;
if (error_code ec = getSymbolName(symb, symname))
if (error_code ec = getSymbolName(getSection(sec->sh_link), symb, symname))
return ec;
switch (Header->e_machine) {
case ELF::EM_X86_64:
@ -1156,6 +1166,16 @@ error_code ELFObjectFile<target_endianness, is64Bits>
return object_error::success;
}
// Verify that the last byte in the string table in a null.
template<support::endianness target_endianness, bool is64Bits>
void ELFObjectFile<target_endianness, is64Bits>
::VerifyStrTab(const Elf_Shdr *sh) const {
const char *strtab = (const char*)base() + sh->sh_offset;
if (strtab[sh->sh_size - 1] != 0)
// FIXME: Proper error handling.
report_fatal_error("String table must end with a null terminator!");
}
template<support::endianness target_endianness, bool is64Bits>
ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
, error_code &ec)
@ -1163,7 +1183,8 @@ ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
, isDyldELFObject(false)
, SectionHeaderTable(0)
, dot_shstrtab_sec(0)
, dot_strtab_sec(0) {
, dot_strtab_sec(0)
, dot_dynstr_sec(0) {
const uint64_t FileSize = Data->getBufferSize();
@ -1194,6 +1215,10 @@ ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
// To find the symbol tables we walk the section table to find SHT_SYMTAB.
const Elf_Shdr* SymbolTableSectionHeaderIndex = 0;
const Elf_Shdr* sh = SectionHeaderTable;
// Reserve SymbolTableSections[0] for .dynsym
SymbolTableSections.push_back(NULL);
for (uint64_t i = 0, e = getNumSections(); i != e; ++i) {
if (sh->sh_type == ELF::SHT_SYMTAB_SHNDX) {
if (SymbolTableSectionHeaderIndex)
@ -1205,6 +1230,13 @@ ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
SymbolTableSectionsIndexMap[i] = SymbolTableSections.size();
SymbolTableSections.push_back(sh);
}
if (sh->sh_type == ELF::SHT_DYNSYM) {
if (SymbolTableSections[0] != NULL)
// FIXME: Proper error handling.
report_fatal_error("More than one .dynsym!");
SymbolTableSectionsIndexMap[i] = 0;
SymbolTableSections[0] = sh;
}
if (sh->sh_type == ELF::SHT_REL || sh->sh_type == ELF::SHT_RELA) {
SectionRelocMap[getSection(sh->sh_info)].push_back(i);
}
@ -1221,10 +1253,7 @@ ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
dot_shstrtab_sec = getSection(getStringTableIndex());
if (dot_shstrtab_sec) {
// Verify that the last byte in the string table in a null.
if (((const char*)base() + dot_shstrtab_sec->sh_offset)
[dot_shstrtab_sec->sh_size - 1] != 0)
// FIXME: Proper error handling.
report_fatal_error("String table must end with a null terminator!");
VerifyStrTab(dot_shstrtab_sec);
}
// Merge this into the above loop.
@ -1239,10 +1268,13 @@ ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
// FIXME: Proper error handling.
report_fatal_error("Already found section named .strtab!");
dot_strtab_sec = sh;
const char *dot_strtab = (const char*)base() + sh->sh_offset;
if (dot_strtab[sh->sh_size - 1] != 0)
// FIXME: Proper error handling.
report_fatal_error("String table must end with a null terminator!");
VerifyStrTab(dot_strtab_sec);
} else if (SectionName == ".dynstr") {
if (dot_dynstr_sec != 0)
// FIXME: Proper error handling.
report_fatal_error("Already found section named .dynstr!");
dot_dynstr_sec = sh;
VerifyStrTab(dot_dynstr_sec);
}
}
}
@ -1268,12 +1300,12 @@ symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_symbols() const {
DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
if (SymbolTableSections.size() == 0) {
if (SymbolTableSections.size() <= 1) {
SymbolData.d.a = std::numeric_limits<uint32_t>::max();
SymbolData.d.b = std::numeric_limits<uint32_t>::max();
} else {
SymbolData.d.a = 1; // The 0th symbol in ELF is fake.
SymbolData.d.b = 0;
SymbolData.d.b = 1; // The 0th table is .dynsym
}
return symbol_iterator(SymbolRef(SymbolData, this));
}
@ -1288,6 +1320,31 @@ symbol_iterator ELFObjectFile<target_endianness, is64Bits>
return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_dynamic_symbols() const {
DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
if (SymbolTableSections[0] == NULL) {
SymbolData.d.a = std::numeric_limits<uint32_t>::max();
SymbolData.d.b = std::numeric_limits<uint32_t>::max();
} else {
SymbolData.d.a = 1; // The 0th symbol in ELF is fake.
SymbolData.d.b = 0; // The 0th table is .dynsym
}
return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
symbol_iterator ELFObjectFile<target_endianness, is64Bits>
::end_dynamic_symbols() const {
DataRefImpl SymbolData;
memset(&SymbolData, 0, sizeof(SymbolData));
SymbolData.d.a = std::numeric_limits<uint32_t>::max();
SymbolData.d.b = std::numeric_limits<uint32_t>::max();
return symbol_iterator(SymbolRef(SymbolData, this));
}
template<support::endianness target_endianness, bool is64Bits>
section_iterator ELFObjectFile<target_endianness, is64Bits>
::begin_sections() const {
@ -1461,7 +1518,8 @@ const char *ELFObjectFile<target_endianness, is64Bits>
template<support::endianness target_endianness, bool is64Bits>
error_code ELFObjectFile<target_endianness, is64Bits>
::getSymbolName(const Elf_Sym *symb,
::getSymbolName(const Elf_Shdr *section,
const Elf_Sym *symb,
StringRef &Result) const {
if (symb->st_name == 0) {
const Elf_Shdr *section = getSection(symb);
@ -1472,8 +1530,13 @@ error_code ELFObjectFile<target_endianness, is64Bits>
return object_error::success;
}
// Use the default symbol table name section.
Result = getString(dot_strtab_sec, symb->st_name);
if (section == SymbolTableSections[0]) {
// Symbol is in .dynsym, use .dynstr string table
Result = getString(dot_dynstr_sec, symb->st_name);
} else {
// Use the default symbol table name section.
Result = getString(dot_strtab_sec, symb->st_name);
}
return object_error::success;
}

View File

@ -32,6 +32,8 @@ public:
virtual symbol_iterator begin_symbols() const;
virtual symbol_iterator end_symbols() const;
virtual symbol_iterator begin_dynamic_symbols() const;
virtual symbol_iterator end_dynamic_symbols() const;
virtual section_iterator begin_sections() const;
virtual section_iterator end_sections() const;

View File

@ -313,6 +313,9 @@ public:
virtual symbol_iterator begin_symbols() const = 0;
virtual symbol_iterator end_symbols() const = 0;
virtual symbol_iterator begin_dynamic_symbols() const = 0;
virtual symbol_iterator end_dynamic_symbols() const = 0;
virtual section_iterator begin_sections() const = 0;
virtual section_iterator end_sections() const = 0;

View File

@ -508,6 +508,16 @@ symbol_iterator COFFObjectFile::end_symbols() const {
return symbol_iterator(SymbolRef(ret, this));
}
symbol_iterator COFFObjectFile::begin_dynamic_symbols() const {
// TODO: implement
report_fatal_error("Dynamic symbols unimplemented in COFFObjectFile");
}
symbol_iterator COFFObjectFile::end_dynamic_symbols() const {
// TODO: implement
report_fatal_error("Dynamic symbols unimplemented in COFFObjectFile");
}
section_iterator COFFObjectFile::begin_sections() const {
DataRefImpl ret;
std::memset(&ret, 0, sizeof(DataRefImpl));

View File

@ -388,6 +388,15 @@ symbol_iterator MachOObjectFile::end_symbols() const {
return symbol_iterator(SymbolRef(DRI, this));
}
symbol_iterator MachOObjectFile::begin_dynamic_symbols() const {
// TODO: implement
report_fatal_error("Dynamic symbols unimplemented in MachOObjectFile");
}
symbol_iterator MachOObjectFile::end_dynamic_symbols() const {
// TODO: implement
report_fatal_error("Dynamic symbols unimplemented in MachOObjectFile");
}
/*===-- Sections ----------------------------------------------------------===*/

Binary file not shown.

Binary file not shown.

View File

@ -0,0 +1,31 @@
; How to make the shared objects from this file:
;
; X86-32 ELF:
; llc -mtriple=i386-linux-gnu shared.ll -filetype=obj -o tmp32.o -relocation-model=pic
; ld -melf_i386 -shared tmp32.o -o shared-object-test.elf-i386 --unresolved-symbols=ignore-all
;
; X86-64 ELF:
; llc -mtriple=x86_64-linux-gnu shared.ll -filetype=obj -o tmp64.o -relocation-model=pic
; ld -melf_x86_64 -shared tmp64.o -o shared-object-test.elf-x86-64 --unresolved-symbols=ignore-all
@defined_sym = global i32 1, align 4
@tls_sym = thread_local global i32 2, align 4
@undef_sym = external global i32
@undef_tls_sym = external thread_local global i32
@common_sym = common global i32 0, align 4
define i32 @global_func() nounwind uwtable {
entry:
ret i32 0
}
declare i32 @undef_func(...)
define internal i32 @local_func() nounwind uwtable {
entry:
ret i32 0
}

View File

@ -0,0 +1,15 @@
RUN: llvm-nm -D %p/Inputs/shared-object-test.elf-i386 \
RUN: | FileCheck %s -check-prefix ELF
RUN: llvm-nm -D %p/Inputs/shared-object-test.elf-x86-64 \
RUN: | FileCheck %s -check-prefix ELF
; Note: tls_sym should be 'D' (not '?'), but TLS is not
; yet recognized by ObjectFile.
ELF: {{[0-9a-f]+}} A __bss_start
ELF: {{[0-9a-f]+}} A _edata
ELF: {{[0-9a-f]+}} A _end
ELF: {{[0-9a-f]+}} B common_sym
ELF: {{[0-9a-f]+}} D defined_sym
ELF: {{[0-9a-f]+}} T global_func
ELF: ? tls_sym

View File

@ -61,6 +61,12 @@ namespace {
cl::alias UndefinedOnly2("u", cl::desc("Alias for --undefined-only"),
cl::aliasopt(UndefinedOnly));
cl::opt<bool> DynamicSyms("dynamic",
cl::desc("Display the dynamic symbols instead "
"of normal symbols."));
cl::alias DynamicSyms2("D", cl::desc("Alias for --dynamic"),
cl::aliasopt(DynamicSyms));
cl::opt<bool> DefinedOnly("defined-only",
cl::desc("Show only defined symbols"));
@ -277,9 +283,13 @@ static void DumpSymbolNamesFromModule(Module *M) {
static void DumpSymbolNamesFromObject(ObjectFile *obj) {
error_code ec;
for (symbol_iterator i = obj->begin_symbols(),
e = obj->end_symbols();
i != e; i.increment(ec)) {
symbol_iterator ibegin = obj->begin_symbols();
symbol_iterator iend = obj->end_symbols();
if (DynamicSyms) {
ibegin = obj->begin_dynamic_symbols();
iend = obj->end_dynamic_symbols();
}
for (symbol_iterator i = ibegin; i != iend; i.increment(ec)) {
if (error(ec)) break;
bool internal;
if (error(i->isInternal(internal))) break;