Initial commit: Go 1.23 release state

test/slice3.go

@@ -0,0 +1,160 @@
+// runoutput
+
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test run-time behavior of 3-index slice expressions.
+
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strconv"
+)
+
+var bout *bufio.Writer
+
+func main() {
+	bout = bufio.NewWriter(os.Stdout)
+
+	fmt.Fprintf(bout, "%s", programTop)
+	fmt.Fprintf(bout, "func main() {\n")
+
+	index := []string{
+		"0",
+		"1",
+		"2",
+		"3",
+		"10",
+		"20",
+		"vminus1",
+		"v0",
+		"v1",
+		"v2",
+		"v3",
+		"v10",
+		"v20",
+	}
+
+	parse := func(s string) (n int, isconst bool) {
+		if s == "vminus1" {
+			return -1, false
+		}
+		isconst = true
+		if s[0] == 'v' {
+			isconst = false
+			s = s[1:]
+		}
+		n, _ = strconv.Atoi(s)
+		return n, isconst
+	}
+
+	const Cap = 10 // cap of slice, array
+
+	for _, base := range []string{"array", "slice"} {
+		for _, i := range index {
+			iv, iconst := parse(i)
+			for _, j := range index {
+				jv, jconst := parse(j)
+				for _, k := range index {
+					kv, kconst := parse(k)
+					// Avoid errors that would make the program not compile.
+					// Those are tested by slice3err.go.
+					switch {
+					case iconst && jconst && iv > jv,
+						jconst && kconst && jv > kv,
+						iconst && kconst && iv > kv,
+						iconst && base == "array" && iv > Cap,
+						jconst && base == "array" && jv > Cap,
+						kconst && base == "array" && kv > Cap:
+						continue
+					}
+
+					expr := base + "[" + i + ":" + j + ":" + k + "]"
+					var xbase, xlen, xcap int
+					if iv > jv || jv > kv || kv > Cap || iv < 0 || jv < 0 || kv < 0 {
+						xbase, xlen, xcap = -1, -1, -1
+					} else {
+						xbase = iv
+						xlen = jv - iv
+						xcap = kv - iv
+					}
+					fmt.Fprintf(bout, "\tcheckSlice(%q, func() []byte { return %s }, %d, %d, %d)\n", expr, expr, xbase, xlen, xcap)
+				}
+			}
+		}
+	}
+
+	fmt.Fprintf(bout, "\tif !ok { os.Exit(1) }\n")
+	fmt.Fprintf(bout, "}\n")
+	bout.Flush()
+}
+
+var programTop = `
+package main
+
+import (
+	"fmt"
+	"os"
+	"unsafe"
+)
+
+var ok = true
+
+var (
+	array = new([10]byte)
+	slice = array[:]
+
+	vminus1 = -1
+	v0 = 0
+	v1 = 1
+	v2 = 2
+	v3 = 3
+	v4 = 4
+	v5 = 5
+	v10 = 10
+	v20 = 20
+)
+
+func notOK() {
+	if ok {
+		println("BUG:")
+		ok = false
+	}
+}
+
+func checkSlice(desc string, f func() []byte, xbase, xlen, xcap int) {
+	defer func() {
+		if err := recover(); err != nil {
+			if xbase >= 0 {
+				notOK()
+				println(desc, " unexpected panic: ", fmt.Sprint(err))
+			}
+		}
+		// "no panic" is checked below
+	}()
+	
+	x := f()
+
+	arrayBase := uintptr(unsafe.Pointer(array))
+	raw := *(*[3]uintptr)(unsafe.Pointer(&x))
+	base, len, cap := raw[0] - arrayBase, raw[1], raw[2]
+	if xbase < 0 {
+		notOK()
+		println(desc, "=", base, len, cap, "want panic")
+		return
+	}
+	if cap != 0 && base != uintptr(xbase) || base >= 10 || len != uintptr(xlen) || cap != uintptr(xcap) {
+		notOK()
+		if cap == 0 {
+			println(desc, "=", base, len, cap, "want", "0-9", xlen, xcap)
+		} else {
+			println(desc, "=", base, len, cap, "want", xbase, xlen, xcap)
+		}
+	}
+}
+
+`