Merge 9654c5ee71 into 49cdf0c42e

Fixes #74199

Change-Id: I6a15fbd59a3a3f8c496440f56d09d695e1504e4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/682576
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Damien Neil <dneil@google.com>

src/cmd/compile/doc.go

@@ -320,17 +320,19 @@ by ``importmodule'' and ``importname''. For example,
 
 causes g to refer to the WebAssembly function f from module a_module.
 
-	//go:wasmexport exportname
+	//go:wasmexport [exportname]
 
 The //go:wasmexport directive is wasm-only and must be followed by a
 function definition.
 It specifies that the function is exported to the wasm host as ``exportname''.
+If exportname is omitted, the function's own name will be used as the export name.
 For example,
-
 	//go:wasmexport h
 	func hWasm() { ... }
-
-make Go function hWasm available outside this WebAssembly module as h.
+makes Go function hWasm available outside this WebAssembly module as h.
+	//go:wasmexport
+	func hWasm() { ... }
+makes Go function hWasm available outside this WebAssembly module as hWasm.
 
 For both go:wasmimport and go:wasmexport,
 the types of parameters and return values to the Go function are translated to

src/cmd/compile/internal/noder/noder.go

@@ -258,19 +258,23 @@ func (p *noder) pragma(pos syntax.Pos, blankLine bool, text string, old syntax.P
 			}
 		}
 
-	case strings.HasPrefix(text, "go:wasmexport "):
+	case strings.HasPrefix(text, "go:wasmexport"):
 		f := strings.Fields(text)
-		if len(f) != 2 {
-			// TODO: maybe make the name optional? It was once mentioned on proposal 65199.
-			p.error(syntax.Error{Pos: pos, Msg: "usage: //go:wasmexport exportname"})
+		if len(f) > 2 {
+			p.error(syntax.Error{Pos: pos, Msg: "usage: //go:wasmexport [exportname]"})
 			break
 		}
 
+		var exportName string
+		if len(f) == 2 {
+			exportName = f[1]
+		}
+
 		if buildcfg.GOARCH == "wasm" {
 			// Only actually use them if we're compiling to WASM though.
 			pragma.WasmExport = &WasmExport{
 				Pos:  pos,
-				Name: f[1],
+				Name: exportName,
 			}
 		}
 

src/cmd/compile/internal/noder/writer.go

@@ -1125,7 +1125,11 @@ func (w *writer) funcExt(obj *types2.Func) {
 			w.String("")
 		}
 		if we != nil {
-			w.String(we.Name)
+			if we.Name != "" {
+				w.String(we.Name)
+			} else {
+				w.String(decl.Name.Value)
+			}
 		} else {
 			w.String("")
 		}

src/crypto/cipher/gcm.go

@@ -82,7 +82,7 @@ func newGCM(cipher Block, nonceSize, tagSize int) (AEAD, error) {
 
 // NewGCMWithRandomNonce returns the given cipher wrapped in Galois Counter
 // Mode, with randomly-generated nonces. The cipher must have been created by
-// [aes.NewCipher].
+// [crypto/aes.NewCipher].
 //
 // It generates a random 96-bit nonce, which is prepended to the ciphertext by Seal,
 // and is extracted from the ciphertext by Open. The NonceSize of the AEAD is zero,

src/go/doc/testdata/issue62640.0.golden

@@ -0,0 +1,22 @@
+// 
+PACKAGE issue62640
+
+IMPORTPATH
+	testdata/issue62640
+
+FILENAMES
+	testdata/issue62640.go
+
+TYPES
+	// 
+	type E struct{}
+
+	// F should be hidden within S because of the S.F field. 
+	func (E) F()
+
+	// 
+	type S struct {
+		E
+		F	int
+	}
+

src/go/doc/testdata/issue62640.1.golden

@@ -0,0 +1,22 @@
+// 
+PACKAGE issue62640
+
+IMPORTPATH
+	testdata/issue62640
+
+FILENAMES
+	testdata/issue62640.go
+
+TYPES
+	// 
+	type E struct{}
+
+	// F should be hidden within S because of the S.F field. 
+	func (E) F()
+
+	// 
+	type S struct {
+		E
+		F	int
+	}
+

src/go/doc/testdata/issue62640.2.golden

@@ -0,0 +1,25 @@
+// 
+PACKAGE issue62640
+
+IMPORTPATH
+	testdata/issue62640
+
+FILENAMES
+	testdata/issue62640.go
+
+TYPES
+	// 
+	type E struct{}
+
+	// F should be hidden within S because of the S.F field. 
+	func (E) F()
+
+	// 
+	type S struct {
+		E
+		F	int
+	}
+
+	// F should be hidden within S because of the S.F field. 
+	func (S) F()
+

src/go/doc/testdata/issue62640.go

@@ -0,0 +1,15 @@
+// Copyright 2025 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 issue62640
+
+type E struct{}
+
+// F should be hidden within S because of the S.F field.
+func (E) F() {}
+
+type S struct {
+	E
+	F int
+}

src/runtime/mheap.go

@@ -312,8 +312,10 @@ type heapArena struct {
 	// during marking.
 	pageSpecials [pagesPerArena / 8]uint8
 
-	// pageUseSpanDartboard is a bitmap that indicates which spans are
-	// heap spans and also gcUsesSpanDartboard.
+	// pageUseSpanInlineMarkBits is a bitmap where each bit corresponds
+	// to a span, as only spans one page in size can have inline mark bits.
+	// The bit indicates that the span has a spanInlineMarkBits struct
+	// stored directly at the top end of the span's memory.
 	pageUseSpanInlineMarkBits [pagesPerArena / 8]uint8
 
 	// checkmarks stores the debug.gccheckmark state. It is only

src/testing/synctest/helper_test.go

@@ -0,0 +1,15 @@
+// Copyright 2025 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 synctest_test
+
+import "testing"
+
+// helperLog is a t.Helper which logs.
+// Since it is a helper, the log prefix should contain
+// the caller's file, not helper_test.go.
+func helperLog(t *testing.T, s string) {
+	t.Helper()
+	t.Log(s)
+}

src/testing/synctest/synctest_test.go

@@ -140,6 +140,18 @@ func TestRun(t *testing.T) {
 	})
 }
 
+func TestHelper(t *testing.T) {
+	runTest(t, []string{"-test.v"}, func() {
+		synctest.Test(t, func(t *testing.T) {
+			helperLog(t, "log in helper")
+		})
+	}, `^=== RUN   TestHelper
+    synctest_test.go:.* log in helper
+--- PASS: TestHelper.*
+PASS
+$`)
+}
+
 func wantPanic(t *testing.T, want string) {
 	if e := recover(); e != nil {
 		if got := fmt.Sprint(e); got != want {

src/testing/testing.go

@@ -1261,6 +1261,9 @@ func (c *common) Skipped() bool {
 // When printing file and line information, that function will be skipped.
 // Helper may be called simultaneously from multiple goroutines.
 func (c *common) Helper() {
+	if c.isSynctest {
+		c = c.parent
+	}
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if c.helperPCs == nil {

test/wasmexport.go

@@ -13,6 +13,9 @@ package p
 //go:wasmexport F
 func F() {} // OK
 
+//go:wasmexport
+func G() {} // OK
+
 type S int32
 
 //go:wasmexport M