109 lines
2.7 KiB
Python
109 lines
2.7 KiB
Python
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#!/usr/bin/env python
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# Copyright 2019 the V8 project authors. All rights reserved.
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# Use of this source code is governed by a BSD-style license that can be found
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# in the LICENSE file.
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import io
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import math
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import struct
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import sys
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CUSTOM_SECTION_ID = 0
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FUNCTION_SECTION_ID = 3
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def peek_uint8(fin):
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bs = fin.peek(1)[:1]
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if len(bs) != 1:
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return None, bs
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return ord(bs[0]), bs
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def read_uint8(fin):
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value, bs = peek_uint8(fin)
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fin.read(len(bs))
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return value, bs
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def peek_uint32(fin):
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bs = fin.peek(4)[:4]
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if len(bs) != 4:
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return None, bs
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return ord(bs[0]) | ord(bs[1]) << 8 | ord(bs[2]) << 16 | ord(bs[3]) << 24, bs
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def read_uint32(fin):
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value, bs = peek_uint32(fin)
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fin.read(len(bs))
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return value, bs
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def peek_varuintN(fin):
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value = 0
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shift = 0
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n = 1
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while True:
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bs = fin.peek(n)[:n]
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if len(bs) < n:
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return None, bs
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b = ord(bs[-1])
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value |= (b & 0x7F) << shift;
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if (b & 0x80) == 0x00:
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return value, bs
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shift += 7;
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n += 1
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def read_varuintN(fin):
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value, bs = peek_varuintN(fin)
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fin.read(len(bs))
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return value, bs
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def to_varuintN(value):
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bs = ""
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while True:
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b = value & 0x7F
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value >>= 7
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if (value != 0x00):
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b |= 0x80
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bs += chr(b)
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if value == 0x00:
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return bs
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def write_varuintN(value, fout):
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bs = to_varuintN(value)
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fout.write(bs)
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return bs
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def peek_magic_number(fin, expected_magic_number=0x6d736100):
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magic_number, bs = peek_uint32(fin)
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assert magic_number == expected_magic_number, "unexpected magic number"
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return magic_number, bs
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def read_magic_number(fin, expected_magic_number=0x6d736100):
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magic_number, bs = peek_magic_number(fin, expected_magic_number)
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fin.read(len(bs))
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return magic_number, bs
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def peek_version(fin, expected_version=1):
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version, bs = peek_uint32(fin)
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assert version == expected_version, "unexpected version"
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return version, bs
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def read_version(fin, expected_version=1):
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version, bs = peek_version(fin, expected_version)
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fin.read(len(bs))
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return version, bs
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def write_custom_section(fout, section_name_bs, payload_bs):
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section_name_length_bs = to_varuintN(len(section_name_bs))
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payload_length_bs = to_varuintN(len(section_name_bs) \
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+ len(section_name_length_bs) + len(payload_bs))
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section_id_bs = to_varuintN(CUSTOM_SECTION_ID)
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fout.write(section_id_bs)
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fout.write(payload_length_bs)
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fout.write(section_name_length_bs)
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fout.write(section_name_bs)
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fout.write(payload_bs)
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def write_compilation_hints_section(fout, hints_bs):
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num_compilation_hints_bs = to_varuintN(len(hints_bs))
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section_name_bs = b"compilationHints"
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payload_bs = num_compilation_hints_bs + hints_bs
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write_custom_section(fout, section_name_bs, payload_bs)
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