llvm-6502/lib/DebugInfo/DWARFFormValue.cpp
Frederic Riss 0275be3a97 Allow DWARFFormValue::extractValue to be called with a null CU.
Currently FormValues are only used for attributes of DIEs and thus
uers always have a CU lying around when calling into the FormValue
API.
Accelerator tables encode their information using the same Forms
as the attributes, thus it is natural to use DWARFFormValue to
extract/dump them. There is no CU in that case though. Allow the
API to be called with a null CU arguemnt by making the RelocMap
lookup conditional on the CU pointer validity. And document this
new behvior in the header. (Test coverage for this use of the API
comes in the DwarfAccelTable support patch)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-11-12 23:48:04 +00:00

558 lines
16 KiB
C++

//===-- DWARFFormValue.cpp ------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/DebugInfo/DWARFFormValue.h"
#include "DWARFCompileUnit.h"
#include "DWARFContext.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
using namespace llvm;
using namespace dwarf;
namespace {
uint8_t getRefAddrSize(uint8_t AddrSize, uint16_t Version) {
// FIXME: Support DWARF64.
return (Version == 2) ? AddrSize : 4;
}
template <uint8_t AddrSize, uint8_t RefAddrSize>
ArrayRef<uint8_t> makeFixedFormSizesArrayRef() {
static const uint8_t sizes[] = {
0, // 0x00 unused
AddrSize, // 0x01 DW_FORM_addr
0, // 0x02 unused
0, // 0x03 DW_FORM_block2
0, // 0x04 DW_FORM_block4
2, // 0x05 DW_FORM_data2
4, // 0x06 DW_FORM_data4
8, // 0x07 DW_FORM_data8
0, // 0x08 DW_FORM_string
0, // 0x09 DW_FORM_block
0, // 0x0a DW_FORM_block1
1, // 0x0b DW_FORM_data1
1, // 0x0c DW_FORM_flag
0, // 0x0d DW_FORM_sdata
4, // 0x0e DW_FORM_strp
0, // 0x0f DW_FORM_udata
RefAddrSize, // 0x10 DW_FORM_ref_addr
1, // 0x11 DW_FORM_ref1
2, // 0x12 DW_FORM_ref2
4, // 0x13 DW_FORM_ref4
8, // 0x14 DW_FORM_ref8
0, // 0x15 DW_FORM_ref_udata
0, // 0x16 DW_FORM_indirect
4, // 0x17 DW_FORM_sec_offset
0, // 0x18 DW_FORM_exprloc
0, // 0x19 DW_FORM_flag_present
};
return makeArrayRef(sizes);
}
}
ArrayRef<uint8_t> DWARFFormValue::getFixedFormSizes(uint8_t AddrSize,
uint16_t Version) {
uint8_t RefAddrSize = getRefAddrSize(AddrSize, Version);
if (AddrSize == 4 && RefAddrSize == 4)
return makeFixedFormSizesArrayRef<4, 4>();
if (AddrSize == 4 && RefAddrSize == 8)
return makeFixedFormSizesArrayRef<4, 8>();
if (AddrSize == 8 && RefAddrSize == 4)
return makeFixedFormSizesArrayRef<8, 4>();
if (AddrSize == 8 && RefAddrSize == 8)
return makeFixedFormSizesArrayRef<8, 8>();
return None;
}
static const DWARFFormValue::FormClass DWARF4FormClasses[] = {
DWARFFormValue::FC_Unknown, // 0x0
DWARFFormValue::FC_Address, // 0x01 DW_FORM_addr
DWARFFormValue::FC_Unknown, // 0x02 unused
DWARFFormValue::FC_Block, // 0x03 DW_FORM_block2
DWARFFormValue::FC_Block, // 0x04 DW_FORM_block4
DWARFFormValue::FC_Constant, // 0x05 DW_FORM_data2
// --- These can be FC_SectionOffset in DWARF3 and below:
DWARFFormValue::FC_Constant, // 0x06 DW_FORM_data4
DWARFFormValue::FC_Constant, // 0x07 DW_FORM_data8
// ---
DWARFFormValue::FC_String, // 0x08 DW_FORM_string
DWARFFormValue::FC_Block, // 0x09 DW_FORM_block
DWARFFormValue::FC_Block, // 0x0a DW_FORM_block1
DWARFFormValue::FC_Constant, // 0x0b DW_FORM_data1
DWARFFormValue::FC_Flag, // 0x0c DW_FORM_flag
DWARFFormValue::FC_Constant, // 0x0d DW_FORM_sdata
DWARFFormValue::FC_String, // 0x0e DW_FORM_strp
DWARFFormValue::FC_Constant, // 0x0f DW_FORM_udata
DWARFFormValue::FC_Reference, // 0x10 DW_FORM_ref_addr
DWARFFormValue::FC_Reference, // 0x11 DW_FORM_ref1
DWARFFormValue::FC_Reference, // 0x12 DW_FORM_ref2
DWARFFormValue::FC_Reference, // 0x13 DW_FORM_ref4
DWARFFormValue::FC_Reference, // 0x14 DW_FORM_ref8
DWARFFormValue::FC_Reference, // 0x15 DW_FORM_ref_udata
DWARFFormValue::FC_Indirect, // 0x16 DW_FORM_indirect
DWARFFormValue::FC_SectionOffset, // 0x17 DW_FORM_sec_offset
DWARFFormValue::FC_Exprloc, // 0x18 DW_FORM_exprloc
DWARFFormValue::FC_Flag, // 0x19 DW_FORM_flag_present
};
bool DWARFFormValue::isFormClass(DWARFFormValue::FormClass FC) const {
// First, check DWARF4 form classes.
if (Form < ArrayRef<FormClass>(DWARF4FormClasses).size() &&
DWARF4FormClasses[Form] == FC)
return true;
// Check DW_FORM_ref_sig8 from DWARF4.
if (Form == DW_FORM_ref_sig8)
return (FC == FC_Reference);
// Check for some DWARF5 forms.
if (Form == DW_FORM_GNU_addr_index)
return (FC == FC_Address);
if (Form == DW_FORM_GNU_str_index)
return (FC == FC_String);
// In DWARF3 DW_FORM_data4 and DW_FORM_data8 served also as a section offset.
// Don't check for DWARF version here, as some producers may still do this
// by mistake.
if ((Form == DW_FORM_data4 || Form == DW_FORM_data8) &&
FC == FC_SectionOffset)
return true;
return false;
}
bool DWARFFormValue::extractValue(DataExtractor data, uint32_t *offset_ptr,
const DWARFUnit *cu) {
bool indirect = false;
bool is_block = false;
Value.data = nullptr;
// Read the value for the form into value and follow and DW_FORM_indirect
// instances we run into
do {
indirect = false;
switch (Form) {
case DW_FORM_addr:
case DW_FORM_ref_addr: {
if (!cu)
return false;
uint16_t AddrSize =
(Form == DW_FORM_addr)
? cu->getAddressByteSize()
: getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr);
if (AI != cu->getRelocMap()->end()) {
const std::pair<uint8_t, int64_t> &R = AI->second;
Value.uval = data.getUnsigned(offset_ptr, AddrSize) + R.second;
} else
Value.uval = data.getUnsigned(offset_ptr, AddrSize);
break;
}
case DW_FORM_exprloc:
case DW_FORM_block:
Value.uval = data.getULEB128(offset_ptr);
is_block = true;
break;
case DW_FORM_block1:
Value.uval = data.getU8(offset_ptr);
is_block = true;
break;
case DW_FORM_block2:
Value.uval = data.getU16(offset_ptr);
is_block = true;
break;
case DW_FORM_block4:
Value.uval = data.getU32(offset_ptr);
is_block = true;
break;
case DW_FORM_data1:
case DW_FORM_ref1:
case DW_FORM_flag:
Value.uval = data.getU8(offset_ptr);
break;
case DW_FORM_data2:
case DW_FORM_ref2:
Value.uval = data.getU16(offset_ptr);
break;
case DW_FORM_data4:
case DW_FORM_ref4: {
Value.uval = data.getU32(offset_ptr);
if (!cu)
break;
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
if (AI != cu->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
case DW_FORM_data8:
case DW_FORM_ref8:
Value.uval = data.getU64(offset_ptr);
break;
case DW_FORM_sdata:
Value.sval = data.getSLEB128(offset_ptr);
break;
case DW_FORM_strp: {
Value.uval = data.getU32(offset_ptr);
if (!cu)
break;
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
if (AI != cu->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
case DW_FORM_udata:
case DW_FORM_ref_udata:
Value.uval = data.getULEB128(offset_ptr);
break;
case DW_FORM_string:
Value.cstr = data.getCStr(offset_ptr);
break;
case DW_FORM_indirect:
Form = data.getULEB128(offset_ptr);
indirect = true;
break;
case DW_FORM_sec_offset: {
// FIXME: This is 64-bit for DWARF64.
Value.uval = data.getU32(offset_ptr);
if (!cu)
break;
RelocAddrMap::const_iterator AI = cu->getRelocMap()->find(*offset_ptr-4);
if (AI != cu->getRelocMap()->end())
Value.uval += AI->second.second;
break;
}
case DW_FORM_flag_present:
Value.uval = 1;
break;
case DW_FORM_ref_sig8:
Value.uval = data.getU64(offset_ptr);
break;
case DW_FORM_GNU_addr_index:
case DW_FORM_GNU_str_index:
Value.uval = data.getULEB128(offset_ptr);
break;
default:
return false;
}
} while (indirect);
if (is_block) {
StringRef str = data.getData().substr(*offset_ptr, Value.uval);
Value.data = nullptr;
if (!str.empty()) {
Value.data = reinterpret_cast<const uint8_t *>(str.data());
*offset_ptr += Value.uval;
}
}
return true;
}
bool
DWARFFormValue::skipValue(DataExtractor debug_info_data, uint32_t* offset_ptr,
const DWARFUnit *cu) const {
return DWARFFormValue::skipValue(Form, debug_info_data, offset_ptr, cu);
}
bool
DWARFFormValue::skipValue(uint16_t form, DataExtractor debug_info_data,
uint32_t *offset_ptr, const DWARFUnit *cu) {
bool indirect = false;
do {
switch (form) {
// Blocks if inlined data that have a length field and the data bytes
// inlined in the .debug_info
case DW_FORM_exprloc:
case DW_FORM_block: {
uint64_t size = debug_info_data.getULEB128(offset_ptr);
*offset_ptr += size;
return true;
}
case DW_FORM_block1: {
uint8_t size = debug_info_data.getU8(offset_ptr);
*offset_ptr += size;
return true;
}
case DW_FORM_block2: {
uint16_t size = debug_info_data.getU16(offset_ptr);
*offset_ptr += size;
return true;
}
case DW_FORM_block4: {
uint32_t size = debug_info_data.getU32(offset_ptr);
*offset_ptr += size;
return true;
}
// Inlined NULL terminated C-strings
case DW_FORM_string:
debug_info_data.getCStr(offset_ptr);
return true;
// Compile unit address sized values
case DW_FORM_addr:
*offset_ptr += cu->getAddressByteSize();
return true;
case DW_FORM_ref_addr:
*offset_ptr += getRefAddrSize(cu->getAddressByteSize(), cu->getVersion());
return true;
// 0 byte values - implied from the form.
case DW_FORM_flag_present:
return true;
// 1 byte values
case DW_FORM_data1:
case DW_FORM_flag:
case DW_FORM_ref1:
*offset_ptr += 1;
return true;
// 2 byte values
case DW_FORM_data2:
case DW_FORM_ref2:
*offset_ptr += 2;
return true;
// 4 byte values
case DW_FORM_strp:
case DW_FORM_data4:
case DW_FORM_ref4:
*offset_ptr += 4;
return true;
// 8 byte values
case DW_FORM_data8:
case DW_FORM_ref8:
case DW_FORM_ref_sig8:
*offset_ptr += 8;
return true;
// signed or unsigned LEB 128 values
// case DW_FORM_APPLE_db_str:
case DW_FORM_sdata:
case DW_FORM_udata:
case DW_FORM_ref_udata:
case DW_FORM_GNU_str_index:
case DW_FORM_GNU_addr_index:
debug_info_data.getULEB128(offset_ptr);
return true;
case DW_FORM_indirect:
indirect = true;
form = debug_info_data.getULEB128(offset_ptr);
break;
// FIXME: 4 for DWARF32, 8 for DWARF64.
case DW_FORM_sec_offset:
*offset_ptr += 4;
return true;
default:
return false;
}
} while (indirect);
return true;
}
void
DWARFFormValue::dump(raw_ostream &OS, const DWARFUnit *cu) const {
uint64_t uvalue = Value.uval;
bool cu_relative_offset = false;
switch (Form) {
case DW_FORM_addr: OS << format("0x%016" PRIx64, uvalue); break;
case DW_FORM_GNU_addr_index: {
OS << format(" indexed (%8.8x) address = ", (uint32_t)uvalue);
uint64_t Address;
if (cu->getAddrOffsetSectionItem(uvalue, Address))
OS << format("0x%016" PRIx64, Address);
else
OS << "<no .debug_addr section>";
break;
}
case DW_FORM_flag_present: OS << "true"; break;
case DW_FORM_flag:
case DW_FORM_data1: OS << format("0x%02x", (uint8_t)uvalue); break;
case DW_FORM_data2: OS << format("0x%04x", (uint16_t)uvalue); break;
case DW_FORM_data4: OS << format("0x%08x", (uint32_t)uvalue); break;
case DW_FORM_ref_sig8:
case DW_FORM_data8: OS << format("0x%016" PRIx64, uvalue); break;
case DW_FORM_string:
OS << '"';
OS.write_escaped(Value.cstr);
OS << '"';
break;
case DW_FORM_exprloc:
case DW_FORM_block:
case DW_FORM_block1:
case DW_FORM_block2:
case DW_FORM_block4:
if (uvalue > 0) {
switch (Form) {
case DW_FORM_exprloc:
case DW_FORM_block: OS << format("<0x%" PRIx64 "> ", uvalue); break;
case DW_FORM_block1: OS << format("<0x%2.2x> ", (uint8_t)uvalue); break;
case DW_FORM_block2: OS << format("<0x%4.4x> ", (uint16_t)uvalue); break;
case DW_FORM_block4: OS << format("<0x%8.8x> ", (uint32_t)uvalue); break;
default: break;
}
const uint8_t* data_ptr = Value.data;
if (data_ptr) {
// uvalue contains size of block
const uint8_t* end_data_ptr = data_ptr + uvalue;
while (data_ptr < end_data_ptr) {
OS << format("%2.2x ", *data_ptr);
++data_ptr;
}
}
else
OS << "NULL";
}
break;
case DW_FORM_sdata: OS << Value.sval; break;
case DW_FORM_udata: OS << Value.uval; break;
case DW_FORM_strp: {
OS << format(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
Optional<const char *> DbgStr = getAsCString(cu);
if (DbgStr.hasValue()) {
OS << '"';
OS.write_escaped(DbgStr.getValue());
OS << '"';
}
break;
}
case DW_FORM_GNU_str_index: {
OS << format(" indexed (%8.8x) string = ", (uint32_t)uvalue);
Optional<const char *> DbgStr = getAsCString(cu);
if (DbgStr.hasValue()) {
OS << '"';
OS.write_escaped(DbgStr.getValue());
OS << '"';
}
break;
}
case DW_FORM_ref_addr:
OS << format("0x%016" PRIx64, uvalue);
break;
case DW_FORM_ref1:
cu_relative_offset = true;
OS << format("cu + 0x%2.2x", (uint8_t)uvalue);
break;
case DW_FORM_ref2:
cu_relative_offset = true;
OS << format("cu + 0x%4.4x", (uint16_t)uvalue);
break;
case DW_FORM_ref4:
cu_relative_offset = true;
OS << format("cu + 0x%4.4x", (uint32_t)uvalue);
break;
case DW_FORM_ref8:
cu_relative_offset = true;
OS << format("cu + 0x%8.8" PRIx64, uvalue);
break;
case DW_FORM_ref_udata:
cu_relative_offset = true;
OS << format("cu + 0x%" PRIx64, uvalue);
break;
// All DW_FORM_indirect attributes should be resolved prior to calling
// this function
case DW_FORM_indirect:
OS << "DW_FORM_indirect";
break;
// Should be formatted to 64-bit for DWARF64.
case DW_FORM_sec_offset:
OS << format("0x%08x", (uint32_t)uvalue);
break;
default:
OS << format("DW_FORM(0x%4.4x)", Form);
break;
}
if (cu_relative_offset)
OS << format(" => {0x%8.8" PRIx64 "}", uvalue + (cu ? cu->getOffset() : 0));
}
Optional<const char *> DWARFFormValue::getAsCString(const DWARFUnit *U) const {
if (!isFormClass(FC_String))
return None;
if (Form == DW_FORM_string)
return Value.cstr;
if (!U)
return None;
uint32_t Offset = Value.uval;
if (Form == DW_FORM_GNU_str_index) {
uint32_t StrOffset;
if (!U->getStringOffsetSectionItem(Offset, StrOffset))
return None;
Offset = StrOffset;
}
if (const char *Str = U->getStringExtractor().getCStr(&Offset)) {
return Str;
}
return None;
}
Optional<uint64_t> DWARFFormValue::getAsAddress(const DWARFUnit *U) const {
if (!isFormClass(FC_Address))
return None;
if (Form == DW_FORM_GNU_addr_index) {
uint32_t Index = Value.uval;
uint64_t Result;
if (!U || !U->getAddrOffsetSectionItem(Index, Result))
return None;
return Result;
}
return Value.uval;
}
Optional<uint64_t> DWARFFormValue::getAsReference(const DWARFUnit *U) const {
if (!isFormClass(FC_Reference))
return None;
switch (Form) {
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
if (!U)
return None;
return Value.uval + U->getOffset();
case DW_FORM_ref_addr:
return Value.uval;
// FIXME: Add proper support for DW_FORM_ref_sig8
default:
return Value.uval;
}
}
Optional<uint64_t> DWARFFormValue::getAsSectionOffset() const {
if (!isFormClass(FC_SectionOffset))
return None;
return Value.uval;
}
Optional<uint64_t> DWARFFormValue::getAsUnsignedConstant() const {
if ((!isFormClass(FC_Constant) && !isFormClass(FC_Flag))
|| Form == DW_FORM_sdata)
return None;
return Value.uval;
}
Optional<ArrayRef<uint8_t>> DWARFFormValue::getAsBlock() const {
if (!isFormClass(FC_Block) && !isFormClass(FC_Exprloc))
return None;
return ArrayRef<uint8_t>(Value.data, Value.uval);
}