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95b1dda1db
With some inputs larger than `BiggestUInt.high`, `parseBiggestUInt` proc
in `parseutils.nim` fails to detect overflow and returns random value.
This is because `rawParseUInt` try to detects overflow with `if prev >
res:` but it doesn't detects the overflow from multiplication.
It is possible that `x *= 10` causes overflow and resulting value is
larger than original value.
Here is example values larger than `BiggestUInt.high` but
`parseBiggestUInt` returns without detecting overflow:
```
22751622367522324480000000
41404969074137497600000000
20701551093035827200000000000000000
22546225502460313600000000000000000
204963831854661632000000000000000000
```
Following code search for values larger than `BiggestUInt.high` and
`parseBiggestUInt` cannot detect overflow:
```nim
import std/[strutils]
const
# Increase this to extend search range
NBits = 34'u
NBitsMax1 = 1'u shl NBits
NBitsMax = NBitsMax1 - 1'u
# Increase this when there are too many results and want to see only larger result.
MinMultiply10 = 14
var nfound = 0
for i in (NBitsMax div 10'u + 1'u) .. NBitsMax:
var
x = i
n10 = 0
for j in 0 ..< NBits:
let px = x
x = (x * 10'u) and NBitsMax
if x < px:
break
inc n10
if n10 >= MinMultiply10:
echo "i = ", i
echo "uint: ", (i shl (64'u - NBits)), '0'.repeat n10
inc nfound
if nfound > 15:
break
echo "found: ", nfound
```
60 lines
2.3 KiB
Nim
60 lines
2.3 KiB
Nim
discard """
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matrix: "--mm:refc; --mm:orc"
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"""
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import unittest, strutils
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block: # parseutils
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check: parseBiggestUInt("0") == 0'u64
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check: parseBiggestUInt("1") == 1'u64
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check: parseBiggestUInt("2") == 2'u64
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check: parseBiggestUInt("10") == 10'u64
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check: parseBiggestUInt("11") == 11'u64
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check: parseBiggestUInt("99") == 99'u64
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check: parseBiggestUInt("123") == 123'u64
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check: parseBiggestUInt("9876") == 9876'u64
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check: parseBiggestUInt("1_234") == 1234'u64
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check: parseBiggestUInt("123__4") == 1234'u64
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for i in 1.BiggestUInt .. 9.BiggestUInt:
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var x = i
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for j in 1 .. 19:
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check parseBiggestUInt((i + '0'.uint).char.repeat j) == x
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x *= 10
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x += i
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check: parseBiggestUInt("18446744073709551609") == 0xFFFF_FFFF_FFFF_FFF9'u64
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check: parseBiggestUInt("18446744073709551610") == 0xFFFF_FFFF_FFFF_FFFA'u64
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check: parseBiggestUInt("18446744073709551611") == 0xFFFF_FFFF_FFFF_FFFB'u64
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check: parseBiggestUInt("18446744073709551612") == 0xFFFF_FFFF_FFFF_FFFC'u64
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check: parseBiggestUInt("18446744073709551613") == 0xFFFF_FFFF_FFFF_FFFD'u64
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check: parseBiggestUInt("18446744073709551614") == 0xFFFF_FFFF_FFFF_FFFE'u64
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check: parseBiggestUInt("18446744073709551615") == 0xFFFF_FFFF_FFFF_FFFF'u64
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551616")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551617")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551618")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551619")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551620")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551621")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551622")
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expect(ValueError):
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discard parseBiggestUInt("18446744073709551623")
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expect(ValueError):
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for i in 0 .. 999:
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discard parseBiggestUInt("18446744073709552" & intToStr(i, 3))
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expect(ValueError):
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discard parseBiggestUInt("22751622367522324480000000")
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expect(ValueError):
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discard parseBiggestUInt("41404969074137497600000000")
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expect(ValueError):
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discard parseBiggestUInt("20701551093035827200000000000000000")
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expect(ValueError):
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discard parseBiggestUInt("225462255024603136000000000000000000")
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expect(ValueError):
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discard parseBiggestUInt("204963831854661632000000000000000000")
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