llvm/tools/llvm-readobj/ARMEHABIPrinter.h
Chandler Carruth 213fb8f11e [cleanup] Add a missing include exposed by resorting other includes.
Should fix the build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199081 91177308-0d34-0410-b5e6-96231b3b80d8
2014-01-13 08:09:47 +00:00

272 lines
9.2 KiB
C++

//===--- ARMEHABIPrinter.h - ARM EHABI Unwind Information Printer ----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_READOBJ_ARMEHABI_PRINTER_H
#define LLVM_READOBJ_ARMEHABI_PRINTER_H
#include "Error.h"
#include "StreamWriter.h"
#include "llvm/Object/ELF.h"
#include "llvm/Object/ELFTypes.h"
#include "llvm/Support/ARMEHABI.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/type_traits.h"
namespace llvm {
namespace ARM {
namespace EHABI {
template <typename ET>
class PrinterContext {
StreamWriter &SW;
const object::ELFFile<ET> *ELF;
typedef typename object::ELFFile<ET>::Elf_Sym Elf_Sym;
typedef typename object::ELFFile<ET>::Elf_Shdr Elf_Shdr;
typedef typename object::ELFFile<ET>::Elf_Rel_Iter Elf_Rel_iterator;
typedef typename object::ELFFile<ET>::Elf_Sym_Iter Elf_Sym_iterator;
typedef typename object::ELFFile<ET>::Elf_Shdr_Iter Elf_Shdr_iterator;
static const size_t IndexTableEntrySize;
static uint64_t PREL31(uint32_t Address, uint32_t Place) {
uint64_t Location = Address & 0x7fffffff;
if (Location & 0x04000000)
Location |= (uint64_t) ~0x7fffffff;
return Location + Place;
}
ErrorOr<StringRef> FunctionAtAddress(unsigned Section, uint64_t Address) const;
const Elf_Shdr *FindExceptionTable(unsigned IndexTableIndex,
off_t IndexTableOffset) const;
void PrintIndexTable(unsigned SectionIndex, const Elf_Shdr *IT) const;
void PrintExceptionTable(const Elf_Shdr *IT, const Elf_Shdr *EHT,
uint64_t TableEntryOffset) const;
void PrintOpcodes(const uint8_t *Entry, size_t Length, off_t Offset) const;
public:
PrinterContext(StreamWriter &Writer, const object::ELFFile<ET> *File)
: SW(Writer), ELF(File) {}
void PrintUnwindInformation() const;
};
template <typename ET>
const size_t PrinterContext<ET>::IndexTableEntrySize = 8;
template <typename ET>
ErrorOr<StringRef> PrinterContext<ET>::FunctionAtAddress(unsigned Section,
uint64_t Address) const {
for (Elf_Sym_iterator SI = ELF->begin_symbols(), SE = ELF->end_symbols();
SI != SE; ++SI)
if (SI->st_shndx == Section && SI->st_value == Address &&
SI->getType() == ELF::STT_FUNC)
return ELF->getSymbolName(SI);
return readobj_error::unknown_symbol;
}
template <typename ET>
const typename object::ELFFile<ET>::Elf_Shdr *
PrinterContext<ET>::FindExceptionTable(unsigned IndexSectionIndex,
off_t IndexTableOffset) const {
/// Iterate through the sections, searching for the relocation section
/// associated with the unwind index table section specified by
/// IndexSectionIndex. Iterate the associated section searching for the
/// relocation associated with the index table entry specified by
/// IndexTableOffset. The symbol is the section symbol for the exception
/// handling table. Use this symbol to recover the actual exception handling
/// table.
for (Elf_Shdr_iterator SI = ELF->begin_sections(), SE = ELF->end_sections();
SI != SE; ++SI) {
if (SI->sh_type == ELF::SHT_REL && SI->sh_info == IndexSectionIndex) {
for (Elf_Rel_iterator RI = ELF->begin_rel(&*SI), RE = ELF->end_rel(&*SI);
RI != RE; ++RI) {
if (RI->r_offset == IndexTableOffset) {
typename object::ELFFile<ET>::Elf_Rela RelA;
RelA.r_offset = RI->r_offset;
RelA.r_info = RI->r_info;
RelA.r_addend = 0;
std::pair<const Elf_Shdr *, const Elf_Sym *> Symbol =
ELF->getRelocationSymbol(&(*SI), &RelA);
return ELF->getSection(Symbol.second);
}
}
}
}
return NULL;
}
template <typename ET>
void PrinterContext<ET>::PrintExceptionTable(const Elf_Shdr *IT,
const Elf_Shdr *EHT,
uint64_t TableEntryOffset) const {
ErrorOr<ArrayRef<uint8_t> > Contents = ELF->getSectionContents(EHT);
if (!Contents)
return;
/// ARM EHABI Section 6.2 - The generic model
///
/// An exception-handling table entry for the generic model is laid out as:
///
/// 3 3
/// 1 0 0
/// +-+------------------------------+
/// |0| personality routine offset |
/// +-+------------------------------+
/// | personality routine data ... |
///
///
/// ARM EHABI Section 6.3 - The ARM-defined compact model
///
/// An exception-handling table entry for the compact model looks like:
///
/// 3 3 2 2 2 2
/// 1 0 8 7 4 3 0
/// +-+---+----+-----------------------+
/// |1| 0 | Ix | data for pers routine |
/// +-+---+----+-----------------------+
/// | more personality routine data |
const support::ulittle32_t Word =
*reinterpret_cast<const support::ulittle32_t *>(Contents->data() + TableEntryOffset);
if (Word & 0x80000000) {
SW.printString("Model", StringRef("Compact"));
unsigned PersonalityIndex = (Word & 0x0f000000) >> 24;
SW.printNumber("PersonalityIndex", PersonalityIndex);
switch (PersonalityIndex) {
case AEABI_UNWIND_CPP_PR0:
llvm_unreachable("Personality 0 should be compact inline!");
break;
case AEABI_UNWIND_CPP_PR1:
case AEABI_UNWIND_CPP_PR2:
unsigned AdditionalWords = (Word & 0x00ff0000) >> 16;
PrintOpcodes(Contents->data() + TableEntryOffset, 2 + 4 * AdditionalWords,
2);
break;
}
} else {
SW.printString("Model", StringRef("Generic"));
uint64_t Address = PREL31(Word, EHT->sh_addr);
SW.printHex("PersonalityRoutineAddress", Address);
if (ErrorOr<StringRef> Name = FunctionAtAddress(EHT->sh_link, Address))
SW.printString("PersonalityRoutineName", *Name);
}
}
template <typename ET>
void PrinterContext<ET>::PrintOpcodes(const uint8_t *Entry,
size_t Length, off_t Offset) const {
ListScope OCC(SW, "Opcodes");
for (unsigned OCI = Offset; OCI < Length + Offset; OCI++)
SW.printHex("Opcode", Entry[OCI ^ 0x3]);
}
template <typename ET>
void PrinterContext<ET>::PrintIndexTable(unsigned SectionIndex,
const Elf_Shdr *IT) const {
ErrorOr<ArrayRef<uint8_t> > Contents = ELF->getSectionContents(IT);
if (!Contents)
return;
/// ARM EHABI Section 5 - Index Table Entries
/// * The first word contains a PREL31 offset to the start of a function with
/// bit 31 clear
/// * The second word contains one of:
/// - The PREL31 offset of the start of the table entry for the function,
/// with bit 31 clear
/// - The exception-handling table entry itself with bit 31 set
/// - The special bit pattern EXIDX_CANTUNWIND, indicating that associated
/// frames cannot be unwound
const support::ulittle32_t *Data =
reinterpret_cast<const support::ulittle32_t *>(Contents->data());
const unsigned Entries = IT->sh_size / IndexTableEntrySize;
ListScope E(SW, "Entries");
for (unsigned Entry = 0; Entry < Entries; ++Entry) {
DictScope E(SW, "Entry");
const support::ulittle32_t Word0 =
Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 0];
const support::ulittle32_t Word1 =
Data[Entry * (IndexTableEntrySize / sizeof(*Data)) + 1];
if (Word0 & 0x80000000) {
errs() << "corrupt unwind data in section " << SectionIndex << "\n";
continue;
}
const uint64_t Offset = PREL31(Word0, IT->sh_addr);
SW.printHex("FunctionAddress", Offset);
if (ErrorOr<StringRef> Name = FunctionAtAddress(IT->sh_link, Offset))
SW.printString("FunctionName", *Name);
if (Word1 == EXIDX_CANTUNWIND) {
SW.printString("Model", StringRef("CantUnwind"));
continue;
}
if (Word1 & 0x80000000) {
SW.printString("Model", StringRef("Compact (Inline)"));
unsigned PersonalityIndex = (Word1 & 0x0f000000) >> 24;
SW.printNumber("PersonalityIndex", PersonalityIndex);
PrintOpcodes(Contents->data() + Entry * IndexTableEntrySize + 4, 3, 1);
} else {
const Elf_Shdr *EHT =
FindExceptionTable(SectionIndex, Entry * IndexTableEntrySize + 4);
if (ErrorOr<StringRef> Name = ELF->getSectionName(EHT))
SW.printString("ExceptionHandlingTable", *Name);
uint64_t TableEntryOffset = PREL31(Word1, IT->sh_addr);
SW.printHex("TableEntryOffset", TableEntryOffset);
PrintExceptionTable(IT, EHT, TableEntryOffset);
}
}
}
template <typename ET>
void PrinterContext<ET>::PrintUnwindInformation() const {
DictScope UI(SW, "UnwindInformation");
int SectionIndex = 0;
for (Elf_Shdr_iterator SI = ELF->begin_sections(), SE = ELF->end_sections();
SI != SE; ++SI, ++SectionIndex) {
if (SI->sh_type == ELF::SHT_ARM_EXIDX) {
const Elf_Shdr *IT = &(*SI);
DictScope UIT(SW, "UnwindIndexTable");
SW.printNumber("SectionIndex", SectionIndex);
if (ErrorOr<StringRef> SectionName = ELF->getSectionName(IT))
SW.printString("SectionName", *SectionName);
SW.printHex("SectionOffset", IT->sh_offset);
PrintIndexTable(SectionIndex, IT);
}
}
}
}
}
}
#endif