void WriteSignedLeb(MappedFileCursor cur, int i)
{
byte b;
do
{
b = (byte)(i & 0x7F);
i >>= 7;
if ((i != 0 || (b & 0x40) != 0) && (i != -1 || (b & 0x40) == 0))
{
b |= 0x80;
}
cur.WriteByte(b);
} while ((b & 0x80) != 0);
}
void WriteLeb(MappedFileCursor cur, int i)
{
byte b;
do
{
b = (byte)(i & 0x7F);
i >>= 7;
if (i != 0)
{
b |= 0x80;
}
cur.WriteByte(b);
} while (i != 0);
}
void MakeLineProgram(MappedFileCursor cur, LineItem[] lines)
{
LineItem line;
LineItem lineLast;
int iLine;
int iOpcode;
int iConstAddPc;
int iAddrDif;
int iLineDif;
bool fFixIt;
iConstAddPc = (255 - m_lineHead.opcode_base) / m_lineHead.line_range;
iLine = 0;
fFixIt = false;
for (; ;)
{
if (iLine >= lines.Length)
{
break;
}
lineLast.Address = 0;
lineLast.File = 1;
lineLast.Line = 1;
lineLast.Column = 0;
lineLast.Discr = 0;
lineLast.IsStmt = m_lineHead.default_is_stmt != 0;
for (; ;)
{
line = lines[iLine++];
if (line.IsStmt != lineLast.IsStmt)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_negate_stmt);
}
if (line.Discr != lineLast.Discr)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_extended_op);
// count of following bytes depends on size of LEB128
byte cb = 2;
uint val = (uint)line.Discr;
while ((val >>= 7) != 0)
{
cb++;
}
cur.WriteByte(cb);
cur.WriteByte((byte)ExtLineOp.DW_LNE_set_discriminator);
WriteLeb(cur, line.Discr);
}
if (line.File != lineLast.File)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_set_file);
WriteLeb(cur, line.File);
}
if (line.Column != lineLast.Column)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_set_column);
WriteLeb(cur, line.Column);
}
iLineDif = line.Line - lineLast.Line;
iAddrDif = (line.Address - lineLast.Address) / m_lineHead.minimum_instruction_length;
if (iAddrDif < 0)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_extended_op);
cur.WriteByte(5);
cur.WriteByte((byte)ExtLineOp.DW_LNE_set_address);
cur.WriteUint((uint)line.Discr);
iAddrDif = 0;
}
if (line.IsEnd)
{
if (iLineDif != 0)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_advance_line);
WriteSignedLeb(cur, iLineDif);
}
if (iAddrDif != 0)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_advance_pc);
WriteLeb(cur, iAddrDif);
}
cur.WriteByte((byte)StdLineOp.DW_LNS_extended_op);
cur.WriteByte(1); // count of following bytes
cur.WriteByte((byte)ExtLineOp.DW_LNE_end_sequence);
break;
}
if (iLineDif < m_lineHead.line_base || iLineDif >= m_lineHead.line_base + m_lineHead.line_range)
{
// line dif exceeds range of special opcode
cur.WriteByte((byte)StdLineOp.DW_LNS_advance_line);
WriteSignedLeb(cur, iLineDif);
iLineDif = 0;
}
FixOpcode:
if (fFixIt || iAddrDif > iConstAddPc)
{
// address dif exceeds range of special opcode
if (fFixIt || iAddrDif > iConstAddPc * 2)
{
// Big dif, use multi-byte opcode
cur.WriteByte((byte)StdLineOp.DW_LNS_advance_pc);
WriteLeb(cur, iAddrDif);
iAddrDif = 0;
}
else
{
// Within range of single byte opcode
cur.WriteByte((byte)StdLineOp.DW_LNS_const_add_pc);
iAddrDif -= iConstAddPc;
}
fFixIt = false;
}
if (iAddrDif == 0 && iLineDif == 0)
{
cur.WriteByte((byte)StdLineOp.DW_LNS_copy);
}
else
{
// Compute special opcode
iOpcode = iLineDif - m_lineHead.line_base + m_lineHead.line_range * iAddrDif + m_lineHead.opcode_base;
if (iOpcode > 255)
{
fFixIt = true;
goto FixOpcode;
}
cur.WriteByte((byte)iOpcode);
}
// Move on to next line
if (iLine >= lines.Length)
{
throw new Exception("Line list did not end with End Sequence");
}
lineLast = line;
}
}
}
