math: add assembly func archExp and archExp2 for riscv64

goos: linux
goarch: riscv64
pkg: math
                       │   math-old    │               math-new               │
                       │    sec/op     │    sec/op     vs base                │
Exp-64                    51.38n ±  0%    31.98n ± 0%  -37.76% (p=0.000 n=10)
ExpGo-64                  59.27n ±  0%    58.48n ± 0%   -1.33% (p=0.000 n=10)
Expm1-64                  26.98n ±  0%    26.98n ± 0%        ~ (p=0.187 n=10)
Exp2-64                   50.04n ±  0%    28.51n ± 0%  -43.03% (p=0.000 n=10)
Exp2Go-64                 57.81n ±  0%    57.81n ± 0%        ~ (p=0.555 n=10)
Frexp-64                  5.629n ±  0%    5.426n ± 0%   -3.60% (p=0.000 n=10)
Ldexp-64                  7.584n ±  0%    7.550n ± 0%   -0.45% (p=0.002 n=10)

Change-Id: Ic122bf9598302f947c6dbf751db591f403c50373

src/cmd/link/internal/ld/macho.go

@@ -461,14 +461,9 @@ func (ctxt *Link) domacho() {
 		if err != nil {
 			Exitf("%v", err)
 		}
-		if load != nil {
-			machoPlatform = load.platform
+		if load != nil && load.platform != PLATFORM_MACOS {
 			ml := newMachoLoad(ctxt.Arch, load.cmd.type_, uint32(len(load.cmd.data)))
 			copy(ml.data, load.cmd.data)
-			if machoPlatform == PLATFORM_MACOS {
-				ml.data[1] = macOS.version()
-				ml.data[2] = macSDK.version()
-			}
 			break
 		}
 	}
@@ -477,7 +472,7 @@ func (ctxt *Link) domacho() {
 		if buildcfg.GOOS == "ios" {
 			machoPlatform = PLATFORM_IOS
 		}
-		if ctxt.LinkMode == LinkInternal && machoPlatform == PLATFORM_MACOS {
+		if load == nil && machoPlatform == PLATFORM_MACOS {
 			ml := newMachoLoad(ctxt.Arch, imacho.LC_BUILD_VERSION, 4)
 			ml.data[0] = uint32(machoPlatform)
 			ml.data[1] = macOS.version()

src/go/printer/math.go

@@ -0,0 +1,28 @@
+// Copyright 2026 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 printer
+
+import "math"
+
+// log2ish returns a crude approximation to log₂(x).
+// The result is only used for heuristic alignment decisions and should
+// not be used where precision matters.
+// The approximation is guaranteed to produce identical results
+// across all architectures.
+func log2ish(x float64) float64 {
+	f, e := math.Frexp(x)
+	return float64(e) + 2*(f-1)
+}
+
+// exp2ish returns a crude approximation to 2**x.
+// The result is only used for heuristic alignment decisions and should
+// not be used where precision matters.
+// The approximation is guaranteed to produce identical results
+// across all architectures.
+func exp2ish(x float64) float64 {
+	n := math.Floor(x)
+	f := x - n
+	return math.Ldexp(1+f, int(n))
+}

src/go/printer/nodes.go

@@ -11,7 +11,6 @@ package printer
 import (
 	"go/ast"
 	"go/token"
-	"math"
 	"strconv"
 	"strings"
 	"unicode"
@@ -183,9 +182,9 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
 
 	// We use the ratio between the geometric mean of the previous key sizes and
 	// the current size to determine if there should be a break in the alignment.
-	// To compute the geometric mean we accumulate the ln(size) values (lnsum)
+	// To compute the geometric mean we accumulate the log₂(size) values (log2sum)
 	// and the number of sizes included (count).
-	lnsum := 0.0
+	log2sum := 0.0
 	count := 0
 
 	// print all list elements
@@ -229,7 +228,7 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
 				useFF = false
 			} else {
 				const r = 2.5                                // threshold
-				geomean := math.Exp(lnsum / float64(count)) // count > 0
+				geomean := exp2ish(log2sum / float64(count)) // count > 0
 				ratio := float64(size) / geomean
 				useFF = r*ratio <= 1 || r <= ratio
 			}
@@ -260,7 +259,7 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
 				// the section), reset the geomean variables since we are
 				// starting a new group of elements with the next element.
 				if nbreaks > 1 {
-					lnsum = 0
+					log2sum = 0
 					count = 0
 				}
 			}
@@ -284,7 +283,7 @@ func (p *printer) exprList(prev0 token.Pos, list []ast.Expr, depth int, mode exp
 		}
 
 		if size > 0 {
-			lnsum += math.Log(float64(size))
+			log2sum += log2ish(float64(size))
 			count++
 		}
 

src/go/printer/testdata/alignment.golden

@@ -170,3 +170,10 @@ var _ = S{
 	F1____:	[]string{},
 	F2:	[]string{},
 }
+
+// Issue #77959: formatting must be consistent across architectures.
+var _ = []any{
+	(expr_size_95_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)(0),	// 0
+	(expr_size_38_xxxxxxxxxxxxxxxxxxxx)(0),	// 1
+	(*expr_size_126_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)(nil),	// 2
+}

src/go/printer/testdata/alignment.input

@@ -177,3 +177,10 @@ var _ = S{
 	},
 	F2: []string{},
 }
+
+// Issue #77959: formatting must be consistent across architectures.
+var _ = []any{
+	(expr_size_95_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)(0), // 0
+	(expr_size_38_xxxxxxxxxxxxxxxxxxxx)(0), // 1
+	(*expr_size_126_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx)(nil), // 2
+}

src/internal/poll/sendfile_windows.go

@@ -68,8 +68,8 @@ func SendFile(fd *FD, src uintptr, size int64) (written int64, err error, handle
 			chunkSize = size
 		}
 
-		fd.setOffset(startpos + written)
 		n, err := fd.execIO('w', func(o *operation) (uint32, error) {
+			o.setOffset(startpos + written)
 			err := syscall.TransmitFile(fd.Sysfd, hsrc, uint32(chunkSize), 0, &o.o, nil, syscall.TF_WRITE_BEHIND)
 			if err != nil {
 				return 0, err

src/math/exp2_asm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build arm64 || loong64
+//go:build arm64 || loong64 || riscv64
 
 package math
 

src/math/exp2_noasm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !arm64 && !loong64
+//go:build !arm64 && !loong64 && !riscv64
 
 package math
 

src/math/exp_asm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build amd64 || arm64 || loong64 || s390x
+//go:build amd64 || arm64 || loong64 || riscv64 || s390x
 
 package math
 

src/math/exp_noasm.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !amd64 && !arm64 && !loong64 && !s390x
+//go:build !amd64 && !arm64 && !loong64 && !riscv64 && !s390x
 
 package math
 

src/math/exp_riscv64.s

@@ -0,0 +1,236 @@
+// Copyright 2026 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.
+
+#include "textflag.h"
+
+#define NearZero	0x3e30000000000000	// 2**-28
+#define PosInf		0x7ff0000000000000
+#define FracMask	0x000fffffffffffff
+#define C1		0x3cb0000000000000	// 2**-52
+
+DATA exprodata<>+0(SB)/8, $0.0
+DATA exprodata<>+8(SB)/8, $0.5
+DATA exprodata<>+16(SB)/8, $1.0
+DATA exprodata<>+24(SB)/8, $2.0
+DATA exprodata<>+32(SB)/8, $6.93147180369123816490e-01	// Ln2Hi
+DATA exprodata<>+40(SB)/8, $1.90821492927058770002e-10	// Ln2Lo
+DATA exprodata<>+48(SB)/8, $1.44269504088896338700e+00	// Log2e
+DATA exprodata<>+56(SB)/8, $7.09782712893383973096e+02	// Overflow
+DATA exprodata<>+64(SB)/8, $-7.45133219101941108420e+02	// Underflow
+DATA exprodata<>+72(SB)/8, $1.0239999999999999e+03	// Overflow2
+DATA exprodata<>+80(SB)/8, $-1.0740e+03			// Underflow2
+DATA exprodata<>+88(SB)/8, $3.7252902984619141e-09	// NearZero
+GLOBL exprodata<>+0(SB), NOPTR|RODATA, $96
+
+DATA expmultirodata<>+0(SB)/8, $1.66666666666666657415e-01	// P1
+DATA expmultirodata<>+8(SB)/8, $-2.77777777770155933842e-03	// P2
+DATA expmultirodata<>+16(SB)/8, $6.61375632143793436117e-05	// P3
+DATA expmultirodata<>+24(SB)/8, $-1.65339022054652515390e-06	// P4
+DATA expmultirodata<>+32(SB)/8, $4.13813679705723846039e-08	// P5
+GLOBL expmultirodata<>+0(SB), NOPTR|RODATA, $40
+
+// Exp returns e**x, the base-e exponential of x.
+// This is an assembly implementation of the method used for function Exp in file exp.go.
+//
+// func Exp(x float64) float64
+TEXT ·archExp(SB),$0-16
+	MOVD	x+0(FP), F0	// F0 = x
+
+	MOV	$exprodata<>+0(SB), X5
+	MOVD	56(X5), F1	// Overflow
+	MOVD	64(X5), F2	// Underflow
+	MOVD	88(X5), F3	// NearZero
+	MOVD	16(X5), F17	// 1.0
+
+	FEQD	F0, F0, X7
+	BEQ	X0, X7, isNaN		// x = NaN, return NaN
+
+	FLTD	F0, F1, X7
+	BNE	X0, X7, overflow	// x > Overflow, return PosInf
+
+	FLTD	F2, F0, X7
+	BNE	X0, X7, underflow	// x < Underflow, return 0
+
+	FABSD	F0, F5
+	FLTD	F3, F5, X7
+	BNE	X0, X7, nearzero	// fabs(x) < NearZero, return 1 + x
+
+	// argument reduction, x = k*ln2 + r,  |r| <= 0.5*ln2
+	// computed as r = hi - lo for extra precision.
+	MOVD	0(X5), F5
+	MOVD	8(X5), F3
+	MOVD	48(X5), F2
+	FLTD	F0, F5, X7
+	BNE	X0, X7, add		// x > 0
+sub:
+	FMSUBD	F0, F2, F3, F3	// Log2e*x - 0.5
+	JMP	2(PC)
+add:
+	FMADDD	F0, F2, F3, F3	// Log2e*x + 0.5
+
+	FCVTLD.RTZ	F3, X16	// float64 -> int64
+	FCVTDL	X16, F3		// int64 -> float64
+
+	MOVD	32(X5), F4
+	MOVD	40(X5), F5
+	FNMSUBD	F3, F4, F0, F4
+	FMULD	F3, F5, F5
+	FSUBD	F5, F4, F6
+	FMULD	F6, F6, F7
+
+	// compute c
+	// r=(FMA x y z) -> FMADDD z, y, x, r
+	// r=(FMA x y z) -> FMADDD x, y, z, r
+	MOV	$expmultirodata<>+0(SB), X6
+	MOVD	32(X6), F8
+	MOVD	24(X6), F9
+	FMADDD	F7, F8, F9, F13
+	MOVD	16(X6), F10
+	FMADDD	F7, F13, F10, F13
+	MOVD	8(X6), F11
+	FMADDD	F7, F13, F11, F13
+	MOVD	0(X6), F12
+	FMADDD	F7, F13, F12, F13
+	FNMSUBD	F21, F8, F6, F8
+
+	// compute y
+	MOVD	24(X5), F14
+	FSUBD	F8, F14, F14
+	FMULD	F6, F8, F15
+	FDIVD	F14, F15, F15
+	FSUBD	F15, F5, F15
+	FSUBD	F4, F15, F15
+	FSUBD	F15, F17, F16
+
+	// inline Ldexp(y, k), benefit:
+	// 1, no parameter pass overhead.
+	// 2, skip unnecessary checks for Inf/NaN/Zero
+	MOVD	F16, X15
+	MOV	$FracMask, X20
+	AND	X20, X15, X17	// fraction
+	SRL	$52, X15, X18	// exponent
+	ADD	X16, X18
+	MOV	$1, X21
+	BGE	X18, X21, normal
+	ADD	$52, X18		// denormal
+	MOV	$C1, X19
+	MOVD	X19, F17
+normal:
+	SLL	$52, X18
+	OR	X18, X17, X15
+	MOVD	X15, F0
+	FMULD	F17, F0, F0		// return m * x
+	MOVD	F0, ret+8(FP)
+	RET
+nearzero:
+	FADDD	F17, F0, F0
+isNaN:
+	MOVD	F0, ret+8(FP)
+	RET
+underflow:
+	MOV	X0, ret+8(FP)
+	RET
+overflow:
+	MOV	$PosInf, X15
+	MOV	X15, ret+8(FP)
+	RET
+
+
+// Exp2 returns 2**x, the base-2 exponential of x.
+// This is an assembly implementation of the method used for function Exp2 in file exp.go.
+//
+// func Exp2(x float64) float64
+TEXT ·archExp2(SB),$0-16
+	MOVD	x+0(FP), F0	// F0 = x
+
+	MOV	$exprodata<>+0(SB), X5
+	MOVD	72(X5), F1	// Overflow2
+	MOVD	80(X5), F2	// Underflow2
+	MOVD	88(X5), F3	// NearZero
+
+	FEQD	F0, F0, X7
+	BEQ	X0, X7, isNaN		// x = NaN, return NaN
+
+	FLTD	F0, F1, X7
+	BNE	X0, X7, overflow	// x > Overflow, return PosInf
+
+	FLTD	F2, F0, X7
+	BNE	X0, X7, underflow	// x < Underflow, return 0
+
+	// argument reduction; x = r*lg(e) + k with |r| <= ln(2)/2
+	// computed as r = hi - lo for extra precision.
+	MOVD	0(X5), F10
+	MOVD	8(X5), F2
+	FLTD	F0, F10, X7
+	BNE	X0, X7, add
+sub:
+	FSUBD	F2, F0, F3	// x - 0.5
+	JMP	2(PC)
+add:
+	FADDD	F2, F0, F3	// x + 0.5
+
+	FCVTLD.RTZ	F3, X16
+	FCVTDL	X16, F3
+
+	MOVD	32(X5), F4
+	MOVD	40(X5), F5
+	FSUBD	F3, F0, F3
+	FMULD	F3, F4, F4
+	FNMSUBD	F5, F3, F10, F5
+	FSUBD	F5, F4, F6
+	FMULD	F6, F6, F7
+
+	// compute c
+	MOV	$expmultirodata<>+0(SB), X6
+	MOVD	32(X6), F13
+	MOVD	24(X6), F9
+	FMADDD	F7, F13, F9, F13
+	MOVD	16(X6), F10
+	FMADDD	F7, F13, F10, F13
+	MOVD	8(X6), F11
+	FMADDD	F7, F13, F11, F13
+	MOVD	0(X6), F12
+	FMADDD	F7, F13, F12, F13
+	FNMSUBD	F7, F13, F6, F13
+
+	// compute y
+	MOVD	24(X5), F14
+	FSUBD	F13, F14, F14
+	FMULD	F6, F13, F15
+	FDIVD	F14, F15, F15
+
+	MOVD	16(X5), F17
+	FSUBD	F15, F5, F15
+	FSUBD	F4, F15, F15
+	FSUBD	F15, F17, F16
+
+	// inline Ldexp(y, k), benefit:
+	// 1, no parameter pass overhead.
+	// 2, skip unnecessary checks for Inf/NaN/Zero
+	MOVD	F16, X15
+	MOV	$FracMask, X20
+	SRL	$52, X15, X18	// exponent
+	AND	X20, X15, X17	// fraction
+	ADD	X16, X18
+	MOV	$1, X21
+	BGE	X18, X21, normal
+
+	ADD	$52, X18		// denormal
+	MOV	$C1, X19
+	MOVD	X19, F17
+normal:
+	SLL	$52, X18
+	OR	X18, X17, X15
+	MOVD	X15, F0
+	FMULD	F17, F0, F0
+isNaN:
+	MOVD	F0, ret+8(FP)
+	RET
+underflow:
+	MOV	X0, ret+8(FP)
+	RET
+overflow:
+	MOV	$PosInf, X15
+	MOV	X15, ret+8(FP)
+	RET

src/net/http/request.go

@@ -558,6 +558,11 @@ const defaultUserAgent = "Go-http-client/1.1"
 // If Body is present, Content-Length is <= 0 and [Request.TransferEncoding]
 // hasn't been set to "identity", Write adds "Transfer-Encoding:
 // chunked" to the header. Body is closed after it is sent.
+//
+// Header values for Host, Content-Length, Transfer-Encoding,
+// and Trailer are not used; these are derived from other Request fields.
+// If the Header does not contain a User-Agent value, Write uses
+// "Go-http-client/1.1".
 func (r *Request) Write(w io.Writer) error {
 	return r.write(w, false, nil, nil)
 }

src/net/http/transport.go

@@ -388,9 +388,8 @@ type dialClientConner interface {
 	// If HTTP/3 proxies are not supported, DialClientConn should return
 	// an error wrapping [errors.ErrUnsupported].
 	//
-	// The RoundTripper returned by DialClientConn may implement
-	// any of the following methods to support the [ClientConn]
-	// method of the same name:
+	// The RoundTripper returned by DialClientConn must also implement the
+	// following methods to support [ClientConn] methods of the same name:
 	//	Close() error
 	//	Err() error
 	// 	Reserve() error
@@ -411,6 +410,16 @@ type dialClientConner interface {
 	DialClientConn(ctx context.Context, address string, proxy *url.URL, internalStateHook func()) (RoundTripper, error)
 }
 
+type closeIdleConnectionser interface {
+	// CloseIdleConnections is called by Transport.CloseIdleConnections.
+	//
+	// The transport will close idle connections created with DialClientConn
+	// before calling this method. The HTTP/3 transport should not attempt to
+	// close idle connections, but may clean up shared resources such as UDP
+	// sockets if no connections remain.
+	CloseIdleConnections()
+}
+
 // h2Transport is the interface we expect to be able to call from
 // net/http against an *http2.Transport that's either bundled into
 // h2_bundle.go or supplied by the user via x/net/http2.
@@ -956,6 +965,9 @@ func (t *Transport) CloseIdleConnections() {
 	if t2 := t.h2transport; t2 != nil {
 		t2.CloseIdleConnections()
 	}
+	if cc, ok := t.h3transport.(closeIdleConnectionser); ok {
+		cc.CloseIdleConnections()
+	}
 }
 
 // prepareTransportCancel sets up state to convert Transport.CancelRequest into context cancelation.
@@ -3088,11 +3100,16 @@ func (pc *persistConn) closeLocked(err error) {
 		pc.t.decConnsPerHost(pc.cacheKey)
 		// Close HTTP/1 (pc.alt == nil) connection.
 		// HTTP/2 closes its connection itself.
+		// Close HTTP/3 connection if it implements io.Closer.
 		if pc.alt == nil {
 			if err != errCallerOwnsConn {
 				pc.conn.Close()
 			}
 			close(pc.closech)
+		} else {
+			if cc, ok := pc.alt.(io.Closer); ok {
+				cc.Close()
+			}
 		}
 	}
 	pc.mutateHeaderFunc = nil

src/net/ip.go

@@ -132,6 +132,10 @@ func (ip IP) IsLoopback() bool {
 
 // IsPrivate reports whether ip is a private address, according to
 // RFC 1918 (IPv4 addresses) and RFC 4193 (IPv6 addresses).
+// That is, it reports whether ip is in 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, or fc00::/7.
+//
+// IsPrivate does not describe a security property of addresses,
+// and should not be used for access control.
 func (ip IP) IsPrivate() bool {
 	if ip4 := ip.To4(); ip4 != nil {
 		// Following RFC 1918, Section 3. Private Address Space which says:

src/net/netip/netip.go

@@ -637,6 +637,9 @@ func (ip Addr) IsGlobalUnicast() bool {
 // (IPv4 addresses) and RFC 4193 (IPv6 addresses). That is, it reports whether
 // ip is in 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, or fc00::/7. This is the
 // same as [net.IP.IsPrivate].
+//
+// IsPrivate does not describe a security property of addresses,
+// and should not be used for access control.
 func (ip Addr) IsPrivate() bool {
 	if ip.Is4In6() {
 		ip = ip.Unmap()

src/net/sendfile.go

@@ -12,6 +12,8 @@ import (
 	"syscall"
 )
 
+var testHookSupportsSendfile func() bool
+
 // sendFile copies the contents of r to c using the sendfile
 // system call to minimize copies.
 //

src/net/sendfile_stub.go

@@ -8,6 +8,8 @@ package net
 
 import "io"
 
+var testHookSupportsSendfile func() bool
+
 func supportsSendfile() bool {
 	return false
 }

src/net/sendfile_test.go

@@ -28,6 +28,16 @@ const (
 	newtonSHA256 = "d4a9ac22462b35e7821a4f2706c211093da678620a8f9997989ee7cf8d507bbd"
 )
 
+func hookSupportsSendfile(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		origHook := testHookSupportsSendfile
+		testHookSupportsSendfile = func() bool { return true }
+		t.Cleanup(func() {
+			testHookSupportsSendfile = origHook
+		})
+	}
+}
+
 // expectSendfile runs f, and verifies that internal/poll.SendFile successfully handles
 // a write to wantConn during f's execution.
 //
@@ -35,6 +45,7 @@ const (
 // expect a call to SendFile.
 func expectSendfile(t *testing.T, wantConn Conn, f func()) {
 	t.Helper()
+	hookSupportsSendfile(t)
 	if !supportsSendfile() {
 		f()
 		return

src/net/sendfile_windows.go

@@ -12,5 +12,8 @@ import "internal/syscall/windows"
 // https://learn.microsoft.com/en-us/windows/win32/api/mswsock/nf-mswsock-transmitfile
 // https://golang.org/issue/73746
 func supportsSendfile() bool {
+	if testHookSupportsSendfile != nil {
+		return testHookSupportsSendfile()
+	}
 	return windows.SupportUnlimitedTransmitFile()
 }

src/runtime/cgo/cgo.go

@@ -20,8 +20,6 @@ package cgo
 #cgo netbsd LDFLAGS: -lpthread
 #cgo openbsd LDFLAGS: -lpthread
 #cgo aix LDFLAGS: -Wl,-berok
-#cgo solaris LDFLAGS: -lxnet
-#cgo solaris LDFLAGS: -lsocket
 
 // Use -fno-stack-protector to avoid problems locating the
 // proper support functions. See issues #52919, #54313, #58385.

src/runtime/cgo/handle.go

@@ -97,6 +97,9 @@ import (
 //	func main() {
 //		val := "hello Go"
 //		h := cgo.NewHandle(val)
+//		// In this example, unsafe.Pointer(&h) is valid because myprint
+//		// does not keep a copy of the pointer. If the C code keeps the
+//		// pointer after the call returns, use runtime.Pinner to pin it.
 //		C.myprint(unsafe.Pointer(&h))
 //		// Output: hello Go
 //	}

src/syscall/syscall_solaris.go

@@ -71,6 +71,9 @@ func Pipe2(p []int, flags int) error {
 	return err
 }
 
+//go:cgo_ldflag "-lxnet"
+//go:cgo_ldflag "-lsocket"
+
 //sys   accept4(s int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (fd int, err error) = libsocket.accept4
 
 func Accept4(fd int, flags int) (int, Sockaddr, error) {

src/testing/helper_test.go

@@ -85,6 +85,28 @@ func TestTBHelperParallel(t *testing.T) {
 	}
 }
 
+// Issue 72794.
+func TestHelperRange(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") == "1" {
+		rangeHelperHelper(t)
+		return
+	}
+
+	t.Parallel()
+
+	cmd := testenv.Command(t, testenv.Executable(t), "-test.run=^TestHelperRange$")
+	cmd = testenv.CleanCmdEnv(cmd)
+	cmd.Env = append(cmd.Env, "GO_WANT_HELPER_PROCESS=1")
+	out, _ := cmd.CombinedOutput()
+	want := `--- FAIL: TestHelperRange \([^)]+\)
+    helperfuncs_test.go:139: range
+    helperfuncs_test.go:139: range
+`
+	if !regexp.MustCompile(want).Match(out) {
+		t.Errorf("got output:\n\n%s\nwant matching:\n\n%s", out, want)
+	}
+}
+
 func BenchmarkTBHelper(b *testing.B) {
 	f1 := func() {
 		b.Helper()

src/testing/helperfuncs_test.go

@@ -122,3 +122,19 @@ func doPanic(t *testing.T, msg string) {
 	t.Helper()
 	panic(msg)
 }
+
+func rangeHelper(t *testing.T, msg string) {
+	t.Helper()
+	iter := func(yield func(int) bool) {
+		if yield(0) {
+			yield(1)
+		}
+	}
+	for range iter {
+		t.Error(msg)
+	}
+}
+
+func rangeHelperHelper(t *testing.T) {
+	rangeHelper(t, "range")
+}

src/testing/testing.go

@@ -816,8 +816,15 @@ func (c *common) frameSkip(skip int) runtime.Frame {
 	}
 	frames := runtime.CallersFrames(pc[:n])
 	var firstFrame, prevFrame, frame runtime.Frame
+	skipRange := false
 	for more := true; more; prevFrame = frame {
 		frame, more = frames.Next()
+		if skipRange {
+			// Skip the iterator function when a helper
+			// functions does a range over function.
+			skipRange = false
+			continue
+		}
 		if frame.Function == "runtime.gopanic" {
 			continue
 		}
@@ -861,7 +868,25 @@ func (c *common) frameSkip(skip int) runtime.Frame {
 				c.helperNames[pcToName(pc)] = struct{}{}
 			}
 		}
-		if _, ok := c.helperNames[frame.Function]; !ok {
+
+		fnName := frame.Function
+		// Ignore trailing -rangeN used for iterator functions.
+		const rangeSuffix = "-range"
+		if suffixIdx := strings.LastIndex(fnName, rangeSuffix); suffixIdx > 0 {
+			ok := true
+			for i := suffixIdx + len(rangeSuffix); i < len(fnName); i++ {
+				if fnName[i] < '0' || fnName[i] > '9' {
+					ok = false
+					break
+				}
+			}
+			if ok {
+				fnName = fnName[:suffixIdx]
+				skipRange = true
+			}
+		}
+
+		if _, ok := c.helperNames[fnName]; !ok {
 			// Found a frame that wasn't inside a helper function.
 			return frame
 		}