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#ifndef __READDWARF_H__
#define __READDWARF_H__
#include <cstring>
#include <string>
#include <vector>
#include "mspdb.h"
typedef unsigned char byte;
inline unsigned int LEB128(byte* &p)
{
unsigned int x = 0;
int shift = 0;
while (*p & 0x80)
{
x |= (*p & 0x7f) << shift;
shift += 7;
p++;
}
x |= *p << shift;
p++;
return x;
}
inline int SLEB128(byte* &p)
{
unsigned int x = 0;
int shift = 0;
while (*p & 0x80)
{
x |= (*p & 0x7f) << shift;
shift += 7;
p++;
}
x |= *p << shift;
if (*p & 0x40)
x |= -(1 << (shift + 7)); // sign extend
p++;
return x;
}
inline unsigned int RD2(byte* &p)
{
unsigned int x = *p++;
x |= *p++ << 8;
return x;
}
inline unsigned int RD4(byte* &p)
{
unsigned int x = *p++;
x |= *p++ << 8;
x |= *p++ << 16;
x |= *p++ << 24;
return x;
}
inline unsigned long long RD8(byte* &p)
{
unsigned long long x = *p++;
for (int shift = 8; shift < 64; shift += 8)
x |= (unsigned long long) *p++ << shift;
return x;
}
inline unsigned long long RDsize(byte* &p, int size)
{
if (size > 8)
size = 8;
unsigned long long x = *p++;
for (int shift = 8; shift < size * 8; shift += 8)
x |= (unsigned long long) *p++ << shift;
return x;
}
enum AttrClass
{
Invalid,
Addr,
Block,
Const,
String,
Flag,
Ref,
ExprLoc,
SecOffset
};
struct DWARF_Attribute
{
AttrClass type;
union
{
unsigned long addr;
struct { byte* ptr; unsigned len; } block;
unsigned long cons;
const char* string;
bool flag;
byte* ref;
struct { byte* ptr; unsigned len; } expr;
unsigned long sec_offset;
};
};
///////////////////////////////////////////////////////////////////////////////
#include "pshpack1.h"
struct DWARF_CompilationUnit
{
unsigned int unit_length; // 12 byte in DWARF-64
unsigned short version;
unsigned int debug_abbrev_offset; // 8 byte in DWARF-64
byte address_size;
bool isDWARF64() const { return unit_length == ~0; }
int refSize() const { return unit_length == ~0 ? 8 : 4; }
};
struct DWARF_FileName
{
const char* file_name;
unsigned int dir_index;
unsigned long lastModification;
unsigned long fileLength;
void read(byte* &p)
{
file_name = (const char*)p;
p += strlen((const char*)p) + 1;
dir_index = LEB128(p);
lastModification = LEB128(p);
fileLength = LEB128(p);
}
};
struct DWARF_InfoData
{
byte* entryPtr;
unsigned entryOff; // offset in the cu
int code;
byte* abbrev;
int tag;
int hasChild;
const char* name;
const char* linkage_name;
const char* dir;
unsigned long byte_size;
byte* sibling;
unsigned long encoding;
unsigned long pclo;
unsigned long pchi;
unsigned long ranges;
byte* type;
byte* containing_type;
byte* specification;
unsigned long inlined;
bool external;
DWARF_Attribute location;
DWARF_Attribute member_location;
DWARF_Attribute frame_base;
long upper_bound;
long lower_bound;
void clear()
{
entryPtr = 0;
code = 0;
abbrev = 0;
tag = 0;
hasChild = 0;
name = 0;
linkage_name = 0;
dir = 0;
byte_size = 0;
sibling = 0;
encoding = 0;
pclo = 0;
pchi = 0;
ranges = 0;
type = 0;
containing_type = 0;
specification = 0;
inlined = 0;
external = 0;
member_location.type = Invalid;
location.type = Invalid;
frame_base.type = Invalid;
upper_bound = 0;
lower_bound = 0;
}
void merge(const DWARF_InfoData& id)
{
if (id.name) name = id.name;
if (id.linkage_name) linkage_name = id.linkage_name;
if (id.dir) dir = id.dir;
if (id.byte_size) byte_size = id.byte_size;
if (id.sibling) sibling = id.sibling;
if (id.encoding) encoding = id.encoding;
if (id.pclo) pclo = id.pclo;
if (id.pchi) pchi = id.pchi;
if (id.type) type = id.type;
if (id.containing_type) containing_type = id.containing_type;
if (id.specification) specification = id.specification;
if (id.inlined) inlined = id.inlined;
if (id.external) external = id.external;
if (id.member_location.type != Invalid) member_location = id.member_location;
if (id.location.type != Invalid) location = id.location;
if (id.frame_base.type != Invalid) frame_base = id.frame_base;
if (id.upper_bound) upper_bound = id.upper_bound;
if (id.lower_bound) lower_bound = id.lower_bound;
}
};
static const int maximum_operations_per_instruction = 1;
struct DWARF_LineNumberProgramHeader
{
unsigned int unit_length; // 12 byte in DWARF-64
unsigned short version;
unsigned int header_length; // 8 byte in DWARF-64
byte minimum_instruction_length;
//byte maximum_operations_per_instruction; (// not in DWARF 2
byte default_is_stmt;
signed char line_base;
byte line_range;
byte opcode_base;
//LEB128 standard_opcode_lengths[opcode_base];
// string include_directories[] // zero byte terminated
// DWARF_FileNames file_names[] // zero byte terminated
};
struct DWARF_LineState
{
// hdr info
std::vector<const char*> include_dirs;
std::vector<DWARF_FileName> files;
unsigned long address;
unsigned int op_index;
unsigned int file;
unsigned int line;
unsigned int column;
bool is_stmt;
bool basic_block;
bool end_sequence;
bool prologue_end;
bool epilogue_end;
unsigned int isa;
unsigned int discriminator;
// not part of the "documented" state
DWARF_FileName* file_ptr;
unsigned long seg_offset;
unsigned long section;
unsigned long last_addr;
std::vector<mspdb::LineInfoEntry> lineInfo;
DWARF_LineState()
{
seg_offset = 0x400000;
init(0);
}
void init(DWARF_LineNumberProgramHeader* hdr)
{
section = -1;
address = 0;
op_index = 0;
file = 1;
line = 1;
column = 0;
is_stmt = hdr && hdr->default_is_stmt != 0;
basic_block = false;
end_sequence = false;
prologue_end = false;
epilogue_end = false;
isa = 0;
discriminator = 0;
}
void advance_addr(DWARF_LineNumberProgramHeader* hdr, int operation_advance)
{
int address_advance = hdr->minimum_instruction_length * ((op_index + operation_advance) / maximum_operations_per_instruction);
address += address_advance;
op_index = (op_index + operation_advance) % maximum_operations_per_instruction;
}
void addLineInfo()
{
#if 0
const char* fname = (file == 0 ? file_ptr->file_name : files[file - 1].file_name);
printf("Adr:%08x Line: %5d File: %s\n", address, line, fname);
#endif
if (address < seg_offset)
return;
mspdb::LineInfoEntry entry;
entry.offset = address - seg_offset;
entry.line = line;
lineInfo.push_back(entry);
}
};
#include "poppack.h"
///////////////////////////////////////////////////////////////////////////////
struct Location
{
enum Type
{
Invalid, // Failed to evaluate the location expression
InReg, // In register (reg)
Abs, // Absolute address (off)
RegRel // Register-relative address ($reg + off)
};
Type type;
int reg;
int off;
bool is_invalid() const { return type == Invalid; }
bool is_inreg() const { return type == InReg; }
bool is_abs() const { return type == Abs; }
bool is_regrel() const { return type == RegRel; }
};
// Attemots to partially evaluate DWARF location expressions.
// The only supported expressions are those, whose result may be represented
// as either an absolute value, a register, or a register-relative address.
Location decodeLocation(const DWARF_Attribute& attr, const Location* frameBase = 0);
class PEImage;
// Debug Information Entry Cursor
class DIECursor
{
public:
DWARF_CompilationUnit* cu;
byte* ptr;
int level;
bool hasChild; // indicates whether the last read DIE has children
byte* sibling;
byte* getDWARFAbbrev(unsigned off, unsigned findcode);
public:
static void setContext(PEImage* img_);
// Create a new DIECursor
DIECursor(DWARF_CompilationUnit* cu_, byte* ptr);
// Reads next sibling DIE. If the last read DIE had any children, they will be skipped over.
// Returns 'false' upon reaching the last sibling on the current level.
bool readSibling(DWARF_InfoData& id);
// Returns cursor that will enumerate children of the last read DIE.
DIECursor getSubtreeCursor();
// Reads the next DIE in physical order, returns 'true' if succeeds.
// If stopAtNull is true, readNext() will stop upon reaching a null DIE (end of the current tree level).
// Otherwise, it will skip null DIEs and stop only at the end of the subtree for which this DIECursor was created.
bool readNext(DWARF_InfoData& id, bool stopAtNull = false);
};
// iterate over DWARF debug_line information
// if mod is null, print them out, otherwise add to module
bool interpretDWARFLines(const PEImage& img, mspdb::Mod* mod);
#endif
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