Add support for relocations to ObjectFile.
Patch by Danil Malyshev!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139314 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/ELFObjectFile.cpp b/lib/Object/ELFObjectFile.cpp
index e2ff4df..15e7652 100644
--- a/lib/Object/ELFObjectFile.cpp
+++ b/lib/Object/ELFObjectFile.cpp
@@ -14,6 +14,7 @@
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
+#include "llvm/ADT/DenseMap.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/Endian.h"
@@ -176,12 +177,89 @@
}
namespace {
+template<support::endianness target_endianness, bool is64Bits, bool isRela>
+struct Elf_Rel_Base;
+
+template<support::endianness target_endianness>
+struct Elf_Rel_Base<target_endianness, false, false> {
+ LLVM_ELF_IMPORT_TYPES(target_endianness, false)
+ Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
+ Elf_Word r_info; // Symbol table index and type of relocation to apply
+};
+
+template<support::endianness target_endianness>
+struct Elf_Rel_Base<target_endianness, true, false> {
+ LLVM_ELF_IMPORT_TYPES(target_endianness, true)
+ Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
+ Elf_Xword r_info; // Symbol table index and type of relocation to apply
+};
+
+template<support::endianness target_endianness>
+struct Elf_Rel_Base<target_endianness, false, true> {
+ LLVM_ELF_IMPORT_TYPES(target_endianness, false)
+ Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
+ Elf_Word r_info; // Symbol table index and type of relocation to apply
+ Elf_Sword r_addend; // Compute value for relocatable field by adding this
+};
+
+template<support::endianness target_endianness>
+struct Elf_Rel_Base<target_endianness, true, true> {
+ LLVM_ELF_IMPORT_TYPES(target_endianness, true)
+ Elf_Addr r_offset; // Location (file byte offset, or program virtual addr)
+ Elf_Xword r_info; // Symbol table index and type of relocation to apply
+ Elf_Sxword r_addend; // Compute value for relocatable field by adding this.
+};
+
+template<support::endianness target_endianness, bool is64Bits, bool isRela>
+struct Elf_Rel_Impl;
+
+template<support::endianness target_endianness, bool isRela>
+struct Elf_Rel_Impl<target_endianness, true, isRela>
+ : Elf_Rel_Base<target_endianness, true, isRela> {
+ using Elf_Rel_Base<target_endianness, true, isRela>::r_info;
+ LLVM_ELF_IMPORT_TYPES(target_endianness, true)
+
+ // These accessors and mutators correspond to the ELF64_R_SYM, ELF64_R_TYPE,
+ // and ELF64_R_INFO macros defined in the ELF specification:
+ uint64_t getSymbol() const { return (r_info >> 32); }
+ unsigned char getType() const {
+ return (unsigned char) (r_info & 0xffffffffL);
+ }
+ void setSymbol(uint64_t s) { setSymbolAndType(s, getType()); }
+ void setType(unsigned char t) { setSymbolAndType(getSymbol(), t); }
+ void setSymbolAndType(uint64_t s, unsigned char t) {
+ r_info = (s << 32) + (t&0xffffffffL);
+ }
+};
+
+template<support::endianness target_endianness, bool isRela>
+struct Elf_Rel_Impl<target_endianness, false, isRela>
+ : Elf_Rel_Base<target_endianness, false, isRela> {
+ using Elf_Rel_Base<target_endianness, false, isRela>::r_info;
+ LLVM_ELF_IMPORT_TYPES(target_endianness, false)
+
+ // These accessors and mutators correspond to the ELF32_R_SYM, ELF32_R_TYPE,
+ // and ELF32_R_INFO macros defined in the ELF specification:
+ uint32_t getSymbol() const { return (r_info >> 8); }
+ unsigned char getType() const { return (unsigned char) (r_info & 0x0ff); }
+ void setSymbol(uint32_t s) { setSymbolAndType(s, getType()); }
+ void setType(unsigned char t) { setSymbolAndType(getSymbol(), t); }
+ void setSymbolAndType(uint32_t s, unsigned char t) {
+ r_info = (s << 8) + t;
+ }
+};
+
+}
+
+namespace {
template<support::endianness target_endianness, bool is64Bits>
class ELFObjectFile : public ObjectFile {
LLVM_ELF_IMPORT_TYPES(target_endianness, is64Bits)
typedef Elf_Shdr_Impl<target_endianness, is64Bits> Elf_Shdr;
typedef Elf_Sym_Impl<target_endianness, is64Bits> Elf_Sym;
+ typedef Elf_Rel_Impl<target_endianness, is64Bits, false> Elf_Rel;
+ typedef Elf_Rel_Impl<target_endianness, is64Bits, true> Elf_Rela;
struct Elf_Ehdr {
unsigned char e_ident[ELF::EI_NIDENT]; // ELF Identification bytes
@@ -206,18 +284,26 @@
unsigned char getDataEncoding() const { return e_ident[ELF::EI_DATA]; }
};
- typedef SmallVector<const Elf_Shdr*, 1> SymbolTableSections_t;
+ typedef SmallVector<const Elf_Shdr*, 1> Sections_t;
+ typedef DenseMap<unsigned, unsigned> IndexMap_t;
const Elf_Ehdr *Header;
const Elf_Shdr *SectionHeaderTable;
const Elf_Shdr *dot_shstrtab_sec; // Section header string table.
const Elf_Shdr *dot_strtab_sec; // Symbol header string table.
- SymbolTableSections_t SymbolTableSections;
+ Sections_t SymbolTableSections;
+ IndexMap_t SymbolTableSectionsIndexMap;
+ Sections_t RelocationTableSections;
void validateSymbol(DataRefImpl Symb) const;
+ bool isRelocationHasAddend(DataRefImpl Rel) const;
+ template<typename T>
+ const T *getEntry(DataRefImpl Entry, Sections_t Sections) const;
const Elf_Sym *getSymbol(DataRefImpl Symb) const;
const Elf_Shdr *getSection(DataRefImpl index) const;
const Elf_Shdr *getSection(uint16_t index) const;
+ const Elf_Rel *getRel(DataRefImpl Rel) const;
+ const Elf_Rela *getRela(DataRefImpl Rela) const;
const char *getString(uint16_t section, uint32_t offset) const;
const char *getString(const Elf_Shdr *section, uint32_t offset) const;
@@ -238,12 +324,25 @@
virtual error_code sectionContainsSymbol(DataRefImpl Sec, DataRefImpl Symb,
bool &Result) const;
+ virtual error_code getRelocationNext(DataRefImpl Rel,
+ RelocationRef &Res) const;
+ virtual error_code getRelocationAddress(DataRefImpl Rel,
+ uint64_t &Res) const;
+ virtual error_code getRelocationSymbol(DataRefImpl Rel,
+ SymbolRef &Res) const;
+ virtual error_code getRelocationType(DataRefImpl Rel,
+ uint32_t &Res) const;
+ virtual error_code getRelocationAdditionalInfo(DataRefImpl Rel,
+ int64_t &Res) const;
+
public:
ELFObjectFile(MemoryBuffer *Object, error_code &ec);
virtual symbol_iterator begin_symbols() const;
virtual symbol_iterator end_symbols() const;
virtual section_iterator begin_sections() const;
virtual section_iterator end_sections() const;
+ virtual relocation_iterator begin_relocations() const;
+ virtual relocation_iterator end_relocations() const;
virtual uint8_t getBytesInAddress() const;
virtual StringRef getFileFormatName() const;
@@ -416,7 +515,8 @@
return ec;
Result = StringSwitch<char>(name)
.StartsWith(".debug", 'N')
- .StartsWith(".note", 'n');
+ .StartsWith(".note", 'n')
+ .Default('?');
return object_error::success;
}
@@ -507,6 +607,121 @@
return object_error::success;
}
+// Relocations
+template<support::endianness target_endianness, bool is64Bits>
+error_code ELFObjectFile<target_endianness, is64Bits>
+ ::getRelocationNext(DataRefImpl Rel,
+ RelocationRef &Result) const {
+ const Elf_Shdr *RelocationTableSection = RelocationTableSections[Rel.d.b];
+
+ // Check to see if we are at the end of this relocation table.
+ if (++Rel.d.a >= RelocationTableSection->getEntityCount()) {
+ // We are at the end. If there are other relocation tables, jump to them.
+ Rel.d.a = 0;
+ // Otherwise return the terminator.
+ if (++Rel.d.b >= SymbolTableSections.size()) {
+ Rel.d.a = std::numeric_limits<uint32_t>::max();
+ Rel.d.b = std::numeric_limits<uint32_t>::max();
+ }
+ }
+
+ Result = RelocationRef(Rel, this);
+ return object_error::success;
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+error_code ELFObjectFile<target_endianness, is64Bits>
+ ::getRelocationSymbol(DataRefImpl Rel,
+ SymbolRef &Result) const {
+ uint32_t symbolIdx;
+ const Elf_Shdr *sec = RelocationTableSections[Rel.d.b];
+ switch (sec->sh_type) {
+ default :
+ report_fatal_error("Invalid section type in Rel!");
+ case ELF::SHT_REL : {
+ symbolIdx = getRel(Rel)->getSymbol();
+ break;
+ }
+ case ELF::SHT_RELA : {
+ symbolIdx = getRela(Rel)->getSymbol();
+ break;
+ }
+ }
+ DataRefImpl SymbolData;
+ IndexMap_t::const_iterator it = SymbolTableSectionsIndexMap.find(sec->sh_link);
+ if (it == SymbolTableSectionsIndexMap.end())
+ report_fatal_error("Relocation symbol table not found!");
+ SymbolData.d.a = symbolIdx;
+ SymbolData.d.b = it->second;
+ Result = SymbolRef(SymbolData, this);
+ return object_error::success;
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+error_code ELFObjectFile<target_endianness, is64Bits>
+ ::getRelocationAddress(DataRefImpl Rel,
+ uint64_t &Result) const {
+ uint64_t offset;
+ const Elf_Shdr *sec = RelocationTableSections[Rel.d.b];
+ switch (sec->sh_type) {
+ default :
+ report_fatal_error("Invalid section type in Rel!");
+ case ELF::SHT_REL : {
+ offset = getRel(Rel)->r_offset;
+ break;
+ }
+ case ELF::SHT_RELA : {
+ offset = getRela(Rel)->r_offset;
+ break;
+ }
+ }
+
+ const Elf_Shdr *secAddr = getSection(sec->sh_info);
+ Result = offset + reinterpret_cast<uintptr_t>(base() + secAddr->sh_offset);
+ return object_error::success;
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+error_code ELFObjectFile<target_endianness, is64Bits>
+ ::getRelocationType(DataRefImpl Rel,
+ uint32_t &Result) const {
+ const Elf_Shdr *sec = RelocationTableSections[Rel.d.b];
+ switch (sec->sh_type) {
+ default :
+ report_fatal_error("Invalid section type in Rel!");
+ case ELF::SHT_REL : {
+ Result = getRel(Rel)->getType();
+ break;
+ }
+ case ELF::SHT_RELA : {
+ Result = getRela(Rel)->getType();
+ break;
+ }
+ }
+ return object_error::success;
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+error_code ELFObjectFile<target_endianness, is64Bits>
+ ::getRelocationAdditionalInfo(DataRefImpl Rel,
+ int64_t &Result) const {
+ const Elf_Shdr *sec = RelocationTableSections[Rel.d.b];
+ switch (sec->sh_type) {
+ default :
+ report_fatal_error("Invalid section type in Rel!");
+ case ELF::SHT_REL : {
+ Result = 0;
+ return object_error::success;
+ }
+ case ELF::SHT_RELA : {
+ Result = getRela(Rel)->r_addend;
+ return object_error::success;
+ }
+ }
+}
+
+
+
template<support::endianness target_endianness, bool is64Bits>
ELFObjectFile<target_endianness, is64Bits>::ELFObjectFile(MemoryBuffer *Object
, error_code &ec)
@@ -529,13 +744,17 @@
// To find the symbol tables we walk the section table to find SHT_STMTAB.
- for (const char *i = reinterpret_cast<const char *>(SectionHeaderTable),
- *e = i + Header->e_shnum * Header->e_shentsize;
- i != e; i += Header->e_shentsize) {
- const Elf_Shdr *sh = reinterpret_cast<const Elf_Shdr*>(i);
+ const Elf_Shdr* sh =
+ reinterpret_cast<const Elf_Shdr*>(SectionHeaderTable);
+ for (unsigned i = 0; i < Header->e_shnum; ++i) {
if (sh->sh_type == ELF::SHT_SYMTAB) {
+ SymbolTableSectionsIndexMap[i] = SymbolTableSections.size();
SymbolTableSections.push_back(sh);
}
+ if (sh->sh_type == ELF::SHT_REL || sh->sh_type == ELF::SHT_RELA) {
+ RelocationTableSections.push_back(sh);
+ }
+ ++sh;
}
// Get string table sections.
@@ -615,6 +834,31 @@
}
template<support::endianness target_endianness, bool is64Bits>
+ObjectFile::relocation_iterator ELFObjectFile<target_endianness, is64Bits>
+ ::begin_relocations() const {
+ DataRefImpl RelData;
+ memset(&RelData, 0, sizeof(RelData));
+ if (RelocationTableSections.size() == 0) {
+ RelData.d.a = std::numeric_limits<uint32_t>::max();
+ RelData.d.b = std::numeric_limits<uint32_t>::max();
+ } else {
+ RelData.d.a = 0;
+ RelData.d.b = 0;
+ }
+ return relocation_iterator(RelocationRef(RelData, this));
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+ObjectFile::relocation_iterator ELFObjectFile<target_endianness, is64Bits>
+ ::end_relocations() const {
+ DataRefImpl RelData;
+ memset(&RelData, 0, sizeof(RelData));
+ RelData.d.a = std::numeric_limits<uint32_t>::max();
+ RelData.d.b = std::numeric_limits<uint32_t>::max();
+ return relocation_iterator(RelocationRef(RelData, this));
+}
+
+template<support::endianness target_endianness, bool is64Bits>
uint8_t ELFObjectFile<target_endianness, is64Bits>::getBytesInAddress() const {
return is64Bits ? 8 : 4;
}
@@ -629,6 +873,8 @@
return "ELF32-i386";
case ELF::EM_X86_64:
return "ELF32-x86-64";
+ case ELF::EM_ARM:
+ return "ELF32-arm";
default:
return "ELF32-unknown";
}
@@ -654,19 +900,41 @@
return Triple::x86;
case ELF::EM_X86_64:
return Triple::x86_64;
+ case ELF::EM_ARM:
+ return Triple::arm;
default:
return Triple::UnknownArch;
}
}
template<support::endianness target_endianness, bool is64Bits>
-const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Sym *
-ELFObjectFile<target_endianness, is64Bits>::getSymbol(DataRefImpl Symb) const {
- const Elf_Shdr *sec = SymbolTableSections[Symb.d.b];
- return reinterpret_cast<const Elf_Sym *>(
+template<typename T>
+inline const T *
+ELFObjectFile<target_endianness, is64Bits>::getEntry(DataRefImpl Entry,
+ Sections_t Sections) const {
+ const Elf_Shdr *sec = Sections[Entry.d.b];
+ return reinterpret_cast<const T *>(
base()
+ sec->sh_offset
- + (Symb.d.a * sec->sh_entsize));
+ + (Entry.d.a * sec->sh_entsize));
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Sym *
+ELFObjectFile<target_endianness, is64Bits>::getSymbol(DataRefImpl Symb) const {
+ return getEntry<Elf_Sym>(Symb, SymbolTableSections);
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Rel *
+ELFObjectFile<target_endianness, is64Bits>::getRel(DataRefImpl Rel) const {
+ return getEntry<Elf_Rel>(Rel, RelocationTableSections);
+}
+
+template<support::endianness target_endianness, bool is64Bits>
+const typename ELFObjectFile<target_endianness, is64Bits>::Elf_Rela *
+ELFObjectFile<target_endianness, is64Bits>::getRela(DataRefImpl Rela) const {
+ return getEntry<Elf_Rela>(Rela, RelocationTableSections);
}
template<support::endianness target_endianness, bool is64Bits>