[dev.typeparams] all: merge master (4711bf3) into dev.typeparams

[gostls13.git] / src / runtime / slice.go

diff --git a/src/runtime/slice.go b/src/runtime/slice.go
index 66e3aff1a4bf35e12a0ef5427d70fd695bf41bc2..e8267be885df1670ed24265c8e5a890709f72a3b 100644 (file)
--- a/src/runtime/slice.go
+++ b/src/runtime/slice.go
@@ -114,19 +114,37 @@ func makeslice64(et *_type, len64, cap64 int64) unsafe.Pointer {
        return makeslice(et, len, cap)
 }
 
-func unsafeslice(et *_type, len int) {
+func unsafeslice(et *_type, ptr unsafe.Pointer, len int) {
+       if len == 0 {
+               return
+       }
+
+       if ptr == nil {
+               panic(errorString("unsafe.Slice: ptr is nil and len is not zero"))
+       }
+
        mem, overflow := math.MulUintptr(et.size, uintptr(len))
        if overflow || mem > maxAlloc || len < 0 {
                panicunsafeslicelen()
        }
 }
 
-func unsafeslice64(et *_type, len64 int64) {
+func unsafeslice64(et *_type, ptr unsafe.Pointer, len64 int64) {
        len := int(len64)
        if int64(len) != len64 {
                panicunsafeslicelen()
        }
-       unsafeslice(et, len)
+       unsafeslice(et, ptr, len)
+}
+
+func unsafeslicecheckptr(et *_type, ptr unsafe.Pointer, len64 int64) {
+       unsafeslice64(et, ptr, len64)
+
+       // Check that underlying array doesn't straddle multiple heap objects.
+       // unsafeslice64 has already checked for overflow.
+       if checkptrStraddles(ptr, uintptr(len64)*et.size) {
+               throw("checkptr: unsafe.Slice result straddles multiple allocations")
+       }
 }
 
 func panicunsafeslicelen() {