crypto/internal/cryptotest: add SkipTestAllocations

[                                                                     ]
[    It has been [ 0 ] days since Filippo broke a TestAllocations.    ]
[                                                                     ]

Concentrate all the skips in one place, so we don't have to re-discover
always the same ones via trial and error.

This might over-skip fixable allocations, but all these targets are not
fast anyway, so they are not worth going back for.

Removed the sysrand TestAllocations because it causes an import loop
with cryptotest and it's covered by TestAllocations in crypto/rand.

Change-Id: Icd40e97f9128e037f567147f8c9dafa758a47fac
Reviewed-on: https://go-review.googlesource.com/c/go/+/626438
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>

src/crypto/ed25519/ed25519_test.go

@@ -9,11 +9,10 @@ import (
 	"bytes"
 	"compress/gzip"
 	"crypto"
-	"crypto/internal/boring"
+	"crypto/internal/cryptotest"
 	"crypto/rand"
 	"crypto/sha512"
 	"encoding/hex"
-	"internal/testenv"
 	"log"
 	"os"
 	"strings"
@@ -319,11 +318,7 @@ func TestMalleability(t *testing.T) {
 }
 
 func TestAllocations(t *testing.T) {
-	if boring.Enabled {
-		t.Skip("skipping allocations test with BoringCrypto")
-	}
-	testenv.SkipIfOptimizationOff(t)
-
+	cryptotest.SkipTestAllocations(t)
 	if allocs := testing.AllocsPerRun(100, func() {
 		seed := make([]byte, SeedSize)
 		message := []byte("Hello, world!")

src/crypto/internal/cryptotest/allocations.go

@@ -0,0 +1,37 @@
+// Copyright 2024 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.
+
+package cryptotest
+
+import (
+	"crypto/internal/boring"
+	"internal/asan"
+	"internal/msan"
+	"internal/race"
+	"internal/testenv"
+	"runtime"
+	"testing"
+)
+
+// SkipTestAllocations skips the test if there are any factors that interfere
+// with allocation optimizations.
+func SkipTestAllocations(t *testing.T) {
+	// Go+BoringCrypto uses cgo.
+	if boring.Enabled {
+		t.Skip("skipping allocations test with BoringCrypto")
+	}
+
+	// The sanitizers sometimes cause allocations.
+	if race.Enabled || msan.Enabled || asan.Enabled {
+		t.Skip("skipping allocations test with sanitizers")
+	}
+
+	// The plan9 crypto/rand allocates.
+	if runtime.GOOS == "plan9" {
+		t.Skip("skipping allocations test on plan9")
+	}
+
+	// Some APIs rely on inliner and devirtualization to allocate on the stack.
+	testenv.SkipIfOptimizationOff(t)
+}

src/crypto/internal/edwards25519/edwards25519_test.go

@@ -5,9 +5,9 @@
 package edwards25519
 
 import (
+	"crypto/internal/cryptotest"
 	"crypto/internal/edwards25519/field"
 	"encoding/hex"
-	"internal/testenv"
 	"reflect"
 	"testing"
 )
@@ -280,8 +280,7 @@ func TestNonCanonicalPoints(t *testing.T) {
 var testAllocationsSink byte
 
 func TestAllocations(t *testing.T) {
-	testenv.SkipIfOptimizationOff(t)
-
+	cryptotest.SkipTestAllocations(t)
 	if allocs := testing.AllocsPerRun(100, func() {
 		p := NewIdentityPoint()
 		p.Add(p, NewGeneratorPoint())

src/crypto/internal/fips/sha3/sha3_test.go

@@ -12,7 +12,6 @@ import (
 	"encoding"
 	"encoding/hex"
 	"fmt"
-	"internal/testenv"
 	"io"
 	"math/rand"
 	"strings"
@@ -370,7 +369,7 @@ func testClone(t *testing.T) {
 var sink byte
 
 func TestAllocations(t *testing.T) {
-	testenv.SkipIfOptimizationOff(t)
+	cryptotest.SkipTestAllocations(t)
 	t.Run("New", func(t *testing.T) {
 		if allocs := testing.AllocsPerRun(10, func() {
 			h := New256()

src/crypto/internal/nistec/nistec_test.go

@@ -7,17 +7,16 @@ package nistec_test
 import (
 	"bytes"
 	"crypto/elliptic"
+	"crypto/internal/cryptotest"
 	"crypto/internal/nistec"
 	"fmt"
-	"internal/testenv"
 	"math/big"
 	"math/rand"
 	"testing"
 )
 
 func TestAllocations(t *testing.T) {
-	testenv.SkipIfOptimizationOff(t)
-
+	cryptotest.SkipTestAllocations(t)
 	t.Run("P224", func(t *testing.T) {
 		if allocs := testing.AllocsPerRun(10, func() {
 			p := nistec.NewP224Point().SetGenerator()

src/crypto/internal/sysrand/rand_test.go

@@ -7,9 +7,6 @@ package sysrand
 import (
 	"bytes"
 	"compress/flate"
-	"internal/asan"
-	"internal/msan"
-	"internal/race"
 	"internal/testenv"
 	"os"
 	"runtime"
@@ -72,27 +69,6 @@ func TestConcurrentRead(t *testing.T) {
 	wg.Wait()
 }
 
-var sink byte
-
-func TestAllocations(t *testing.T) {
-	if race.Enabled || msan.Enabled || asan.Enabled {
-		t.Skip("urandomRead allocates under -race, -asan, and -msan")
-	}
-	if runtime.GOOS == "plan9" {
-		t.Skip("plan9 allocates")
-	}
-	testenv.SkipIfOptimizationOff(t)
-
-	n := int(testing.AllocsPerRun(10, func() {
-		buf := make([]byte, 32)
-		Read(buf)
-		sink ^= buf[0]
-	}))
-	if n > 0 {
-		t.Errorf("allocs = %d, want 0", n)
-	}
-}
-
 // TestNoUrandomFallback ensures the urandom fallback is not reached in
 // normal operations.
 func TestNoUrandomFallback(t *testing.T) {

src/crypto/md5/md5_test.go

@@ -225,6 +225,7 @@ func TestLargeHashes(t *testing.T) {
 }
 
 func TestAllocations(t *testing.T) {
+	cryptotest.SkipTestAllocations(t)
 	in := []byte("hello, world!")
 	out := make([]byte, 0, Size)
 	h := New()

src/crypto/rand/rand_test.go

@@ -7,15 +7,11 @@ package rand
 import (
 	"bytes"
 	"compress/flate"
-	"crypto/internal/boring"
+	"crypto/internal/cryptotest"
 	"errors"
-	"internal/asan"
-	"internal/msan"
-	"internal/race"
 	"internal/testenv"
 	"io"
 	"os"
-	"runtime"
 	"sync"
 	"testing"
 )
@@ -157,18 +153,7 @@ func testConcurrentRead(t *testing.T, Read func([]byte) (int, error)) {
 var sink byte
 
 func TestAllocations(t *testing.T) {
-	if boring.Enabled {
-		// Might be fixable with https://go.dev/issue/56378.
-		t.Skip("boringcrypto allocates")
-	}
-	if race.Enabled || msan.Enabled || asan.Enabled {
-		t.Skip("urandomRead allocates under -race, -asan, and -msan")
-	}
-	if runtime.GOOS == "plan9" {
-		t.Skip("plan9 allocates")
-	}
-	testenv.SkipIfOptimizationOff(t)
-
+	cryptotest.SkipTestAllocations(t)
 	n := int(testing.AllocsPerRun(10, func() {
 		buf := make([]byte, 32)
 		Read(buf)

src/crypto/rsa/rsa_test.go

@@ -8,7 +8,7 @@ import (
 	"bufio"
 	"bytes"
 	"crypto"
-	"crypto/internal/boring"
+	"crypto/internal/cryptotest"
 	"crypto/rand"
 	. "crypto/rsa"
 	"crypto/sha1"
@@ -17,7 +17,6 @@ import (
 	"encoding/pem"
 	"flag"
 	"fmt"
-	"internal/testenv"
 	"math/big"
 	"strings"
 	"testing"
@@ -132,10 +131,7 @@ func testKeyBasics(t *testing.T, priv *PrivateKey) {
 }
 
 func TestAllocations(t *testing.T) {
-	if boring.Enabled {
-		t.Skip("skipping allocations test with BoringCrypto")
-	}
-	testenv.SkipIfOptimizationOff(t)
+	cryptotest.SkipTestAllocations(t)
 
 	m := []byte("Hello Gophers")
 	c, err := EncryptPKCS1v15(rand.Reader, &test2048Key.PublicKey, m)

src/crypto/sha1/sha1_test.go

@@ -231,9 +231,7 @@ func TestLargeHashes(t *testing.T) {
 }
 
 func TestAllocations(t *testing.T) {
-	if boring.Enabled {
-		t.Skip("BoringCrypto doesn't allocate the same way as stdlib")
-	}
+	cryptotest.SkipTestAllocations(t)
 	in := []byte("hello, world!")
 	out := make([]byte, 0, Size)
 	h := New()

src/crypto/sha256/sha256_test.go

@@ -8,12 +8,10 @@ package sha256
 
 import (
 	"bytes"
-	"crypto/internal/boring"
 	"crypto/internal/cryptotest"
 	"encoding"
 	"fmt"
 	"hash"
-	"internal/testenv"
 	"io"
 	"testing"
 )
@@ -298,10 +296,7 @@ func TestLargeHashes(t *testing.T) {
 }
 
 func TestAllocations(t *testing.T) {
-	testenv.SkipIfOptimizationOff(t)
-	if boring.Enabled {
-		t.Skip("BoringCrypto doesn't allocate the same way as stdlib")
-	}
+	cryptotest.SkipTestAllocations(t)
 	if n := testing.AllocsPerRun(10, func() {
 		in := []byte("hello, world!")
 		out := make([]byte, 0, Size)

src/crypto/sha512/sha512_test.go

@@ -8,13 +8,11 @@ package sha512
 
 import (
 	"bytes"
-	"crypto/internal/boring"
 	"crypto/internal/cryptotest"
 	"encoding"
 	"encoding/hex"
 	"fmt"
 	"hash"
-	"internal/testenv"
 	"io"
 	"testing"
 )
@@ -903,10 +901,7 @@ func TestLargeHashes(t *testing.T) {
 }
 
 func TestAllocations(t *testing.T) {
-	testenv.SkipIfOptimizationOff(t)
-	if boring.Enabled {
-		t.Skip("BoringCrypto doesn't allocate the same way as stdlib")
-	}
+	cryptotest.SkipTestAllocations(t)
 	if n := testing.AllocsPerRun(10, func() {
 		in := []byte("hello, world!")
 		out := make([]byte, 0, Size)