cmd/compile: add support for unsafe.{String,StringData,SliceData}

For #53003

Change-Id: I13a761daca8b433b271a1feb711c103d9820772d
Reviewed-on: https://go-review.googlesource.com/c/go/+/423774
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: hopehook <hopehook@golangcn.org>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

1 files changed, 0 insertions, 48 deletions

diff --git a/src/runtime/slice.go b/src/runtime/slice.go
index e537f15826..0a203e4101 100644
--- a/src/runtime/slice.go
+++ b/src/runtime/slice.go
@@ -123,54 +123,6 @@ func mulUintptr(a, b uintptr) (uintptr, bool) {
 	return math.MulUintptr(a, b)
 }
 
-// Keep this code in sync with cmd/compile/internal/walk/builtin.go:walkUnsafeSlice
-func unsafeslice(et *_type, ptr unsafe.Pointer, len int) {
-	if len < 0 {
-		panicunsafeslicelen()
-	}
-
-	if et.size == 0 {
-		if ptr == nil && len > 0 {
-			panicunsafeslicenilptr()
-		}
-	}
-
-	mem, overflow := math.MulUintptr(et.size, uintptr(len))
-	if overflow || mem > -uintptr(ptr) {
-		if ptr == nil {
-			panicunsafeslicenilptr()
-		}
-		panicunsafeslicelen()
-	}
-}
-
-// Keep this code in sync with cmd/compile/internal/walk/builtin.go:walkUnsafeSlice
-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)
-
-	// 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"))
-}
-
-func panicunsafeslicenilptr() {
-	panic(errorString("unsafe.Slice: ptr is nil and len is not zero"))
-}
-
 // 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