Merge from trunk revision 104c05c5284b7822d770ee51a7d91946c7e56d50.

1 files changed, 41 insertions, 0 deletions

diff --git a/libgo/go/runtime/slice.go b/libgo/go/runtime/slice.go
index 27a9777..8654aba 100644
--- a/libgo/go/runtime/slice.go
+++ b/libgo/go/runtime/slice.go
@@ -18,6 +18,8 @@ import (
 //go:linkname checkMakeSlice
 //go:linkname makeslice64
 //go:linkname growslice
+//go:linkname unsafeslice
+//go:linkname unsafeslice64
 
 type slice struct {
 	array unsafe.Pointer
@@ -127,6 +129,45 @@ func makeslice64(et *_type, len64, cap64 int64) unsafe.Pointer {
 	return makeslice(et, len, cap)
 }
 
+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, ptr unsafe.Pointer, len64 int64) {
+	len := int(len64)
+	if int64(len) != len64 {
+		panicunsafeslicelen()
+	}
+	unsafeslice(et, ptr, len)
+}
+
+func unsafeslicecheckptr(et *_type, ptr unsafe.Pointer, len64 int64) {
+	unsafeslice64(et, ptr, len64)
+
+	/* Commented out for gofrontend.
+	// 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() {
+	panic(errorString("unsafe.Slice: len out of range"))
+}
+
 // growslice handles slice growth during append.
 // It is passed the slice element type, the old slice, and the desired new minimum capacity,
 // and it returns a new slice with at least that capacity, with the old data