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Use unsigned int in itoa to avoid relying on the behaviour of

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signed integer overflow when negating the most negative
integer.

R=rsc
DELTA=11  (0 added, 7 deleted, 4 changed)
OCL=16105
CL=16120
This commit is contained in:
Ian Lance Taylor 2008-09-29 13:40:23 -07:00
parent e4a61c6524
commit 489b5001e2
1 changed files with 4 additions and 11 deletions
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15
src/lib/strings.go
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@ -168,30 +168,23 @@ export func itoa(i int) string {
} }
neg := false; // negative neg := false; // negative
bigneg := false; // largest negative number u := uint(i);
if i < 0 { if i < 0 {
neg = true; neg = true;
i = -i; u = -u;
if i < 0 {
bigneg = true; // is largest negative int
i-- // now positive
}
} }
// Assemble decimal in reverse order. // Assemble decimal in reverse order.
var b [32]byte; var b [32]byte;
bp := len(b); bp := len(b);
for ; i > 0; i /= 10 { for ; u > 0; u /= 10 {
bp--; bp--;
b[bp] = byte(i%10) + '0' b[bp] = byte(u%10) + '0'
} }
if neg { // add sign if neg { // add sign
bp--; bp--;
b[bp] = '-' b[bp] = '-'
} }
if bigneg { // account for i-- above
b[len(b)-1]++
}
// BUG return string(b[bp:len(b)]) // BUG return string(b[bp:len(b)])
return string((&b)[bp:len(b)]) return string((&b)[bp:len(b)])