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core/vm: Rename + updated doc on jumpdest analysis

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This commit is contained in:
Martin Holst Swende 2017-09-08 12:47:44 +02:00
parent 54b1de67e2
commit d6681ed360
2 changed files with 5 additions and 5 deletions
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8
core/vm/analysis.go
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@ -38,7 +38,7 @@ func (d destinations) has(codehash common.Hash, code []byte, dest *big.Int) bool
m, analysed := d[codehash]
if !analysed {
m = jumpdests(code)
m = codeBitmap(code)
d[codehash] = m
}
return OpCode(code[udest]) == JUMPDEST && m.codeSegment(udest)
@ -61,9 +61,9 @@ func (bits *bitvec) codeSegment(pos uint64) bool {
return ((*bits)[pos/8] & (0x80 >> (pos % 8))) == 0
}
// jumpdests creates a map that contains an entry for each
// PC location that is a JUMPDEST instruction.
func jumpdests(code []byte) []byte {
// jumpdests creates a bitmap of the code, where 1 represents a DATA-segment,
// and 0 represents code-segment
func codeBitmap(code []byte) []byte {
//The map is 4 bytes longer than necessary, in case the code
// ends with a PUSH32, the algorithm will push zeroes onto the
// bitvector outside the bounds of the actual code.

2
core/vm/analysis_test.go
View File

@ -28,7 +28,7 @@ func TestJumpDestAnalysis(t *testing.T) {
{[]byte{byte(PUSH32)}, 0xFF, 2},
}
for _, test := range tests {
ret := jumpdests(test.code)
ret := codeBitmap(test.code)
if ret[test.which] != test.exp {
t.Fatalf("expected %x, got %02x", test.exp, ret[test.which])
}