This patch to libgo fixes the build for ARM GNU/Linux. It was failing with
../../../libgo/go/internal/cpu/cpu.go:138:2: error: reference to undefined name 'doinit' 138 | doinit() | ^ This patch fixes it by adding in Go 1.12 internal/cpu/cpu_arm.go, and the code in runtime that initializes the values. This fixes GCC PR 88927. Ian
Index: gcc/go/gofrontend/MERGE =================================================================== --- gcc/go/gofrontend/MERGE (revision 268130) +++ gcc/go/gofrontend/MERGE (working copy) @@ -1,4 +1,4 @@ -0c870ba6b3b43e0e56231f40c56b58dad0e36d9e +fb44f62e7c01ebc987dad78875f593da18100007 The first line of this file holds the git revision number of the last merge done from the gofrontend repository. Index: libgo/go/internal/cpu/cpu_arm.go =================================================================== --- libgo/go/internal/cpu/cpu_arm.go (nonexistent) +++ libgo/go/internal/cpu/cpu_arm.go (working copy) @@ -0,0 +1,33 @@ +// Copyright 2017 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 cpu + +// arm doesn't have a 'cpuid' equivalent, so we rely on HWCAP/HWCAP2. +// These are linknamed in runtime/os_(linux|freebsd)_arm.go and are +// initialized by archauxv(). +// These should not be changed after they are initialized. +var HWCap uint +var HWCap2 uint + +// HWCAP/HWCAP2 bits. These are exposed by Linux and FreeBSD. +const ( + hwcap_VFPv4 = 1 << 16 + hwcap_IDIVA = 1 << 17 +) + +func doinit() { + options = []option{ + {Name: "vfpv4", Feature: &ARM.HasVFPv4}, + {Name: "idiva", Feature: &ARM.HasIDIVA}, + } + + // HWCAP feature bits + ARM.HasVFPv4 = isSet(HWCap, hwcap_VFPv4) + ARM.HasIDIVA = isSet(HWCap, hwcap_IDIVA) +} + +func isSet(hwc uint, value uint) bool { + return hwc&value != 0 +} Index: libgo/go/runtime/os_linux_arm.go =================================================================== --- libgo/go/runtime/os_linux_arm.go (revision 268078) +++ libgo/go/runtime/os_linux_arm.go (working copy) @@ -4,6 +4,8 @@ package runtime +import "internal/cpu" + var randomNumber uint32 func archauxv(tag, val uintptr) { @@ -14,5 +16,9 @@ func archauxv(tag, val uintptr) { // it as a byte array. randomNumber = uint32(startupRandomData[4]) | uint32(startupRandomData[5])<<8 | uint32(startupRandomData[6])<<16 | uint32(startupRandomData[7])<<24 + case _AT_HWCAP: + cpu.HWCap = uint(val) + case _AT_HWCAP2: + cpu.HWCap2 = uint(val) } }