// +build amd64 // errorcheck -0 -d=ssa/check_bce/debug=3 package main func f0(a []int) { a[0] = 1 // ERROR "Found IsInBounds$" a[0] = 1 a[6] = 1 // ERROR "Found IsInBounds$" a[6] = 1 a[5] = 1 a[5] = 1 } func f1(a [256]int, i int) { useInt(a[i]) // ERROR "Found IsInBounds$" useInt(a[i%256]) // ERROR "Found IsInBounds$" useInt(a[i&255]) useInt(a[i&17]) if 4 <= i && i < len(a) { useInt(a[i]) useInt(a[i-1]) // ERROR "Found IsInBounds$" // TODO: 'if 4 <= i && i < len(a)' gets rewritten to 'if uint(i - 4) < 256 - 4', // which the bounds checker cannot yet use to infer that the next line doesn't need a bounds check. useInt(a[i-4]) } } func f2(a [256]int, i uint) { useInt(a[i]) // ERROR "Found IsInBounds$" useInt(a[i%256]) useInt(a[i&255]) useInt(a[i&17]) } func f3(a [256]int, i uint8) { useInt(a[i]) useInt(a[i+10]) useInt(a[i+14]) } func f4(a [27]int, i uint8) { useInt(a[i%15]) useInt(a[i%19]) useInt(a[i%27]) } func f5(a []int) { if len(a) > 5 { useInt(a[5]) useSlice(a[6:]) useSlice(a[:6]) // ERROR "Found IsSliceInBounds$" } } func f6(a [32]int, b [64]int, i int) { useInt(a[uint32(i*0x07C4ACDD)>>27]) useInt(b[uint64(i*0x07C4ACDD)>>58]) useInt(a[uint(i*0x07C4ACDD)>>59]) // The following bounds should not be removed because they can overflow. useInt(a[uint32(i*0x106297f105d0cc86)>>26]) // ERROR "Found IsInBounds$" useInt(b[uint64(i*0x106297f105d0cc86)>>57]) // ERROR "Found IsInBounds$" useInt(a[int32(i*0x106297f105d0cc86)>>26]) // ERROR "Found IsInBounds$" useInt(b[int64(i*0x106297f105d0cc86)>>57]) // ERROR "Found IsInBounds$" } func g1(a []int) { for i := range a { a[i] = i useSlice(a[:i+1]) useSlice(a[:i]) } } func g2(a []int) { useInt(a[3]) // ERROR "Found IsInBounds$" useInt(a[2]) useInt(a[1]) useInt(a[0]) } func g3(a []int) { for i := range a[:256] { // ERROR "Found IsSliceInBounds$" useInt(a[i]) // ERROR "Found IsInBounds$" } b := a[:256] for i := range b { useInt(b[i]) } } func g4(a [100]int) { for i := 10; i < 50; i++ { useInt(a[i-10]) useInt(a[i]) useInt(a[i+25]) useInt(a[i+50]) // The following are out of bounds. useInt(a[i-11]) // ERROR "Found IsInBounds$" useInt(a[i+51]) // ERROR "Found IsInBounds$" } } //go:noinline func useInt(a int) { } //go:noinline func useSlice(a []int) { } func main() { }