new

Change-Id: I6dec60bfec56e1c0b0bfa8ab2c65f305af426bfb

src/hash/maphash/maphash.go

@@ -13,7 +13,6 @@
 package maphash
 
 import (
-	"fmt"
 	"internal/abi"
 	"internal/byteorder"
 	"math"
@@ -296,11 +295,10 @@ func Comparable[T comparable](seed Seed, v T) uint64 {
 }
 
 func comparableReady[T comparable](v T) {
-	// Let v be on the heap,
+	// Force v to be on the heap.
-	// make sure that if v is a pointer to a variable inside the function,
+	// We cannot hash pointers to local variables,
-	// if v and the value it points to do not change,
+	// as the address of the local variable
-	// Comparable(seed,v) before goroutine stack growth
+	// might change on stack growth.
-	// is equal to Comparable(seed,v) after goroutine stack growth.
 	abi.Escape(v)
 }
 
@@ -374,7 +372,7 @@ func appendT(h *Hash, v reflect.Value) {
 		appendT(h, v.Elem())
 		return
 	}
-	panic(fmt.Errorf("hash/maphash: %s not comparable", v.Type().String()))
+	panic("maphash: " + v.Type().String() + " not comparable")
 }
 
 func (h *Hash) float64(f float64) {

src/hash/maphash/maphash_test.go

@@ -6,12 +6,10 @@ package maphash
 
 import (
 	"bytes"
-	"crypto/rand"
 	"fmt"
 	"hash"
 	"math"
 	"reflect"
-	"strings"
 	"testing"
 	"unsafe"
 )
@@ -268,21 +266,10 @@ func testComparableNoEqual[T comparable](t *testing.T, v1, v2 T) {
 	}
 }
 
-var heapStrValue []byte
+var heapStrValue = []byte("aTestString")
 
-//go:noinline
 func heapStr(t *testing.T) string {
-	s := make([]byte, 10)
+	return string(heapStrValue)
-	if heapStrValue != nil {
-		copy(s, heapStrValue)
-	} else {
-		_, err := rand.Read(s)
-		if err != nil {
-			t.Fatal(err)
-		}
-		heapStrValue = s
-	}
-	return string(s)
 }
 
 func testComparable[T comparable](t *testing.T, v T, v2 ...T) {
@@ -405,14 +392,15 @@ func TestComparableShouldPanic(t *testing.T) {
 	defer func() {
 		err := recover()
 		if err == nil {
-			t.Fatalf("hash any([]byte) should panic(error) in maphash.appendT")
+			t.Fatalf("hash any([]byte) should panic in maphash.appendT")
 		}
-		e, ok := err.(error)
+		s, ok := err.(string)
 		if !ok {
-			t.Fatalf("hash any([]byte) should panic(error) in maphash.appendT")
+			t.Fatalf("hash any([]byte) should panic in maphash.appendT")
 		}
-		if !strings.Contains(e.Error(), "comparable") {
+		want := "maphash: []uint8 not comparable"
-			t.Fatalf("hash any([]byte) should panic(error) in maphash.appendT")
+		if s != want {
+			t.Fatalf("want %s, got %s", want, s)
 		}
 	}()
 	Comparable(MakeSeed(), a)