Files
clang-p2996/lldb/source/Plugins/SymbolFile/DWARF/DWARFFormValue.cpp
Pavel Labath 57d053511f Fix incorrect form test in SymbolFileDWARF
Summary:
We were checking whether an attribute is in block form by getting the block data pointer, which
was not correct as the pointer be null even if the attribute is in block form. Other places in
the file already use the correct test.

To make this work, I've needed to add DW_FORM_exprlock to the list of "block" forms, which seems
correct as that is how we are parsing it.

Reviewers: clayborg

Subscribers: lldb-commits

Differential Revision: https://reviews.llvm.org/D22756

llvm-svn: 276735
2016-07-26 08:16:19 +00:00

690 lines
21 KiB
C++

//===-- DWARFFormValue.cpp --------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include <assert.h>
#include "lldb/Core/dwarf.h"
#include "lldb/Core/Stream.h"
#include "DWARFFormValue.h"
#include "DWARFCompileUnit.h"
class DWARFCompileUnit;
using namespace lldb_private;
static uint8_t g_form_sizes_addr4[] =
{
0, // 0x00 unused
4, // 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
0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later
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
0, // 0x1a
0, // 0x1b
0, // 0x1c
0, // 0x1d
0, // 0x1e
0, // 0x1f
8, // 0x20 DW_FORM_ref_sig8
};
static uint8_t
g_form_sizes_addr8[] =
{
0, // 0x00 unused
8, // 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
0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later
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
0, // 0x1a
0, // 0x1b
0, // 0x1c
0, // 0x1d
0, // 0x1e
0, // 0x1f
8, // 0x20 DW_FORM_ref_sig8
};
// Difference with g_form_sizes_addr8:
// DW_FORM_strp and DW_FORM_sec_offset are 8 instead of 4
static uint8_t
g_form_sizes_addr8_dwarf64[] =
{
0, // 0x00 unused
8, // 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
8, // 0x0e DW_FORM_strp
0, // 0x0f DW_FORM_udata
0, // 0x10 DW_FORM_ref_addr (addr size for DWARF2 and earlier, 4 bytes for DWARF32, 8 bytes for DWARF32 in DWARF 3 and later
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
8, // 0x17 DW_FORM_sec_offset
0, // 0x18 DW_FORM_exprloc
0, // 0x19 DW_FORM_flag_present
0, // 0x1a
0, // 0x1b
0, // 0x1c
0, // 0x1d
0, // 0x1e
0, // 0x1f
8, // 0x20 DW_FORM_ref_sig8
};
DWARFFormValue::FixedFormSizes
DWARFFormValue::GetFixedFormSizesForAddressSize (uint8_t addr_size, bool is_dwarf64)
{
if (!is_dwarf64) {
switch (addr_size)
{
case 4: return FixedFormSizes(g_form_sizes_addr4, sizeof(g_form_sizes_addr4));
case 8: return FixedFormSizes(g_form_sizes_addr8, sizeof(g_form_sizes_addr8));
}
} else {
if (addr_size == 8)
return FixedFormSizes(g_form_sizes_addr8_dwarf64, sizeof(g_form_sizes_addr8_dwarf64));
// is_dwarf64 && addr_size == 4 : no provider does this.
}
return FixedFormSizes();
}
DWARFFormValue::DWARFFormValue() :
m_cu (NULL),
m_form(0),
m_value()
{
}
DWARFFormValue::DWARFFormValue(const DWARFCompileUnit* cu, dw_form_t form) :
m_cu (cu),
m_form(form),
m_value()
{
}
void
DWARFFormValue::Clear()
{
m_cu = nullptr;
m_form = 0;
memset(&m_value, 0, sizeof(m_value));
}
bool
DWARFFormValue::ExtractValue(const DWARFDataExtractor& data, lldb::offset_t* offset_ptr)
{
bool indirect = false;
bool is_block = false;
m_value.data = NULL;
uint8_t ref_addr_size;
// Read the value for the form into value and follow and DW_FORM_indirect instances we run into
do
{
indirect = false;
switch (m_form)
{
case DW_FORM_addr: assert(m_cu);
m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::GetAddressByteSize(m_cu)); break;
case DW_FORM_block2: m_value.value.uval = data.GetU16(offset_ptr); is_block = true; break;
case DW_FORM_block4: m_value.value.uval = data.GetU32(offset_ptr); is_block = true; break;
case DW_FORM_data2: m_value.value.uval = data.GetU16(offset_ptr); break;
case DW_FORM_data4: m_value.value.uval = data.GetU32(offset_ptr); break;
case DW_FORM_data8: m_value.value.uval = data.GetU64(offset_ptr); break;
case DW_FORM_string: m_value.value.cstr = data.GetCStr(offset_ptr); break;
case DW_FORM_exprloc:
case DW_FORM_block: m_value.value.uval = data.GetULEB128(offset_ptr); is_block = true; break;
case DW_FORM_block1: m_value.value.uval = data.GetU8(offset_ptr); is_block = true; break;
case DW_FORM_data1: m_value.value.uval = data.GetU8(offset_ptr); break;
case DW_FORM_flag: m_value.value.uval = data.GetU8(offset_ptr); break;
case DW_FORM_sdata: m_value.value.sval = data.GetSLEB128(offset_ptr); break;
case DW_FORM_strp: assert(m_cu);
m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break;
// case DW_FORM_APPLE_db_str:
case DW_FORM_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break;
case DW_FORM_ref_addr: assert(m_cu);
ref_addr_size = 4;
if (m_cu->GetVersion() <= 2)
ref_addr_size = m_cu->GetAddressByteSize();
else
ref_addr_size = m_cu->IsDWARF64() ? 8 : 4;
m_value.value.uval = data.GetMaxU64(offset_ptr, ref_addr_size); break;
case DW_FORM_ref1: m_value.value.uval = data.GetU8(offset_ptr); break;
case DW_FORM_ref2: m_value.value.uval = data.GetU16(offset_ptr); break;
case DW_FORM_ref4: m_value.value.uval = data.GetU32(offset_ptr); break;
case DW_FORM_ref8: m_value.value.uval = data.GetU64(offset_ptr); break;
case DW_FORM_ref_udata: m_value.value.uval = data.GetULEB128(offset_ptr); break;
case DW_FORM_indirect:
m_form = data.GetULEB128(offset_ptr);
indirect = true;
break;
case DW_FORM_sec_offset: assert(m_cu);
m_value.value.uval = data.GetMaxU64(offset_ptr, DWARFCompileUnit::IsDWARF64(m_cu) ? 8 : 4); break;
case DW_FORM_flag_present: m_value.value.uval = 1; break;
case DW_FORM_ref_sig8: m_value.value.uval = data.GetU64(offset_ptr); break;
case DW_FORM_GNU_str_index: m_value.value.uval = data.GetULEB128(offset_ptr); break;
case DW_FORM_GNU_addr_index: m_value.value.uval = data.GetULEB128(offset_ptr); break;
default:
return false;
break;
}
} while (indirect);
if (is_block)
{
m_value.data = data.PeekData(*offset_ptr, m_value.value.uval);
if (m_value.data != NULL)
{
*offset_ptr += m_value.value.uval;
}
}
return true;
}
bool
DWARFFormValue::SkipValue(const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr) const
{
return DWARFFormValue::SkipValue(m_form, debug_info_data, offset_ptr, m_cu);
}
bool
DWARFFormValue::SkipValue(dw_form_t form, const DWARFDataExtractor& debug_info_data, lldb::offset_t *offset_ptr, const DWARFCompileUnit* cu)
{
uint8_t ref_addr_size;
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: { dw_uleb128_t size = debug_info_data.GetULEB128(offset_ptr); *offset_ptr += size; } return true;
case DW_FORM_block1: { dw_uleb128_t size = debug_info_data.GetU8(offset_ptr); *offset_ptr += size; } return true;
case DW_FORM_block2: { dw_uleb128_t size = debug_info_data.GetU16(offset_ptr); *offset_ptr += size; } return true;
case DW_FORM_block4: { dw_uleb128_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 += DWARFCompileUnit::GetAddressByteSize(cu);
return true;
case DW_FORM_ref_addr:
ref_addr_size = 4;
assert (cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong
if (cu->GetVersion() <= 2)
ref_addr_size = cu->GetAddressByteSize();
else
ref_addr_size = cu->IsDWARF64() ? 8 : 4;
*offset_ptr += ref_addr_size;
return true;
// 0 bytes values (implied from DW_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;
// 32 bit for DWARF 32, 64 for DWARF 64
case DW_FORM_sec_offset:
case DW_FORM_strp:
assert(cu);
*offset_ptr += (cu->IsDWARF64() ? 8 : 4);
return true;
// 4 byte values
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_sdata:
case DW_FORM_udata:
case DW_FORM_ref_udata:
case DW_FORM_GNU_addr_index:
case DW_FORM_GNU_str_index:
debug_info_data.Skip_LEB128(offset_ptr);
return true;
case DW_FORM_indirect:
{
dw_form_t indirect_form = debug_info_data.GetULEB128(offset_ptr);
return DWARFFormValue::SkipValue (indirect_form,
debug_info_data,
offset_ptr,
cu);
}
default:
break;
}
return false;
}
void
DWARFFormValue::Dump(Stream &s) const
{
uint64_t uvalue = Unsigned();
bool cu_relative_offset = false;
bool verbose = s.GetVerbose();
switch (m_form)
{
case DW_FORM_addr: s.Address(uvalue, sizeof (uint64_t)); break;
case DW_FORM_flag:
case DW_FORM_data1: s.PutHex8(uvalue); break;
case DW_FORM_data2: s.PutHex16(uvalue); break;
case DW_FORM_sec_offset:
case DW_FORM_data4: s.PutHex32(uvalue); break;
case DW_FORM_ref_sig8:
case DW_FORM_data8: s.PutHex64(uvalue); break;
case DW_FORM_string: s.QuotedCString(AsCString()); 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 (m_form)
{
case DW_FORM_exprloc:
case DW_FORM_block: s.Printf("<0x%" PRIx64 "> ", uvalue); break;
case DW_FORM_block1: s.Printf("<0x%2.2x> ", (uint8_t)uvalue); break;
case DW_FORM_block2: s.Printf("<0x%4.4x> ", (uint16_t)uvalue); break;
case DW_FORM_block4: s.Printf("<0x%8.8x> ", (uint32_t)uvalue); break;
default: break;
}
const uint8_t* data_ptr = m_value.data;
if (data_ptr)
{
const uint8_t* end_data_ptr = data_ptr + uvalue; // uvalue contains size of block
while (data_ptr < end_data_ptr)
{
s.Printf("%2.2x ", *data_ptr);
++data_ptr;
}
}
else
s.PutCString("NULL");
}
break;
case DW_FORM_sdata: s.PutSLEB128(uvalue); break;
case DW_FORM_udata: s.PutULEB128(uvalue); break;
case DW_FORM_strp:
{
const char* dbg_str = AsCString();
if (dbg_str)
{
if (verbose)
s.Printf(" .debug_str[0x%8.8x] = ", (uint32_t)uvalue);
s.QuotedCString(dbg_str);
}
else
{
s.PutHex32(uvalue);
}
}
break;
case DW_FORM_ref_addr:
{
assert (m_cu); // CU must be valid for DW_FORM_ref_addr objects or we will get this wrong
if (m_cu->GetVersion() <= 2)
s.Address(uvalue, sizeof (uint64_t) * 2);
else
s.Address(uvalue, 4 * 2);// 4 for DWARF32, 8 for DWARF64, but we don't support DWARF64 yet
break;
}
case DW_FORM_ref1: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%2.2x", (uint8_t)uvalue); break;
case DW_FORM_ref2: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint16_t)uvalue); break;
case DW_FORM_ref4: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%4.4x", (uint32_t)uvalue); break;
case DW_FORM_ref8: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%8.8" PRIx64, uvalue); break;
case DW_FORM_ref_udata: cu_relative_offset = true; if (verbose) s.Printf("cu + 0x%" PRIx64, uvalue); break;
// All DW_FORM_indirect attributes should be resolved prior to calling this function
case DW_FORM_indirect: s.PutCString("DW_FORM_indirect"); break;
case DW_FORM_flag_present: break;
default:
s.Printf("DW_FORM(0x%4.4x)", m_form);
break;
}
if (cu_relative_offset)
{
assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong
if (verbose)
s.PutCString(" => ");
s.Printf("{0x%8.8" PRIx64 "}", uvalue + m_cu->GetOffset());
}
}
const char*
DWARFFormValue::AsCString() const
{
SymbolFileDWARF* symbol_file = m_cu->GetSymbolFileDWARF();
if (m_form == DW_FORM_string)
{
return m_value.value.cstr;
}
else if (m_form == DW_FORM_strp)
{
if (!symbol_file)
return nullptr;
return symbol_file->get_debug_str_data().PeekCStr(m_value.value.uval);
}
else if (m_form == DW_FORM_GNU_str_index)
{
if (!symbol_file)
return nullptr;
uint32_t index_size = m_cu->IsDWARF64() ? 8 : 4;
lldb::offset_t offset = m_value.value.uval * index_size;
dw_offset_t str_offset = symbol_file->get_debug_str_offsets_data().GetMaxU64(&offset, index_size);
return symbol_file->get_debug_str_data().PeekCStr(str_offset);
}
return nullptr;
}
dw_addr_t
DWARFFormValue::Address() const
{
SymbolFileDWARF* symbol_file = m_cu->GetSymbolFileDWARF();
if (m_form == DW_FORM_addr)
return Unsigned();
assert(m_cu);
assert(m_form == DW_FORM_GNU_addr_index);
if (!symbol_file)
return 0;
uint32_t index_size = m_cu->GetAddressByteSize();
dw_offset_t addr_base = m_cu->GetAddrBase();
lldb::offset_t offset = addr_base + m_value.value.uval * index_size;
return symbol_file->get_debug_addr_data().GetMaxU64(&offset, index_size);
}
uint64_t
DWARFFormValue::Reference() const
{
uint64_t die_offset = m_value.value.uval;
switch (m_form)
{
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
assert (m_cu); // CU must be valid for DW_FORM_ref forms that are compile unit relative or we will get this wrong
die_offset += m_cu->GetOffset();
break;
default:
break;
}
return die_offset;
}
uint64_t
DWARFFormValue::Reference (dw_offset_t base_offset) const
{
uint64_t die_offset = m_value.value.uval;
switch (m_form)
{
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
die_offset += base_offset;
break;
default:
break;
}
return die_offset;
}
const uint8_t*
DWARFFormValue::BlockData() const
{
return m_value.data;
}
bool
DWARFFormValue::IsBlockForm(const dw_form_t form)
{
switch (form)
{
case DW_FORM_exprloc:
case DW_FORM_block:
case DW_FORM_block1:
case DW_FORM_block2:
case DW_FORM_block4:
return true;
}
return false;
}
bool
DWARFFormValue::IsDataForm(const dw_form_t form)
{
switch (form)
{
case DW_FORM_sdata:
case DW_FORM_udata:
case DW_FORM_data1:
case DW_FORM_data2:
case DW_FORM_data4:
case DW_FORM_data8:
return true;
}
return false;
}
int
DWARFFormValue::Compare (const DWARFFormValue& a_value,
const DWARFFormValue& b_value)
{
dw_form_t a_form = a_value.Form();
dw_form_t b_form = b_value.Form();
if (a_form < b_form)
return -1;
if (a_form > b_form)
return 1;
switch (a_form)
{
case DW_FORM_addr:
case DW_FORM_flag:
case DW_FORM_data1:
case DW_FORM_data2:
case DW_FORM_data4:
case DW_FORM_data8:
case DW_FORM_udata:
case DW_FORM_ref_addr:
case DW_FORM_sec_offset:
case DW_FORM_flag_present:
case DW_FORM_ref_sig8:
case DW_FORM_GNU_addr_index:
{
uint64_t a = a_value.Unsigned();
uint64_t b = b_value.Unsigned();
if (a < b)
return -1;
if (a > b)
return 1;
return 0;
}
case DW_FORM_sdata:
{
int64_t a = a_value.Signed();
int64_t b = b_value.Signed();
if (a < b)
return -1;
if (a > b)
return 1;
return 0;
}
case DW_FORM_string:
case DW_FORM_strp:
case DW_FORM_GNU_str_index:
{
const char *a_string = a_value.AsCString();
const char *b_string = b_value.AsCString();
if (a_string == b_string)
return 0;
else if (a_string && b_string)
return strcmp(a_string, b_string);
else if (a_string == NULL)
return -1; // A string is NULL, and B is valid
else
return 1; // A string valid, and B is NULL
}
case DW_FORM_block:
case DW_FORM_block1:
case DW_FORM_block2:
case DW_FORM_block4:
case DW_FORM_exprloc:
{
uint64_t a_len = a_value.Unsigned();
uint64_t b_len = b_value.Unsigned();
if (a_len < b_len)
return -1;
if (a_len > b_len)
return 1;
// The block lengths are the same
return memcmp(a_value.BlockData(), b_value.BlockData(), a_value.Unsigned());
}
break;
case DW_FORM_ref1:
case DW_FORM_ref2:
case DW_FORM_ref4:
case DW_FORM_ref8:
case DW_FORM_ref_udata:
{
uint64_t a = a_value.Reference();
uint64_t b = b_value.Reference();
if (a < b)
return -1;
if (a > b)
return 1;
return 0;
}
case DW_FORM_indirect:
assert(!"This shouldn't happen after the form has been extracted...");
break;
default:
assert(!"Unhandled DW_FORM");
break;
}
return -1;
}