From c52beb108779b8d983136fa5200ab91005c6de49 Mon Sep 17 00:00:00 2001 From: Joel Sing Date: Mon, 17 Dec 2018 01:18:51 +1100 Subject: [PATCH] runtime,cmd/dist,cmd/link: add cgo support on openbsd/arm Add support for cgo on openbsd/arm.The gcc shipped with base OpenBSD armv7 is old/inadequate, so use clang by default. Change-Id: I945a26d369378952d357727718e69249411e1127 Reviewed-on: https://go-review.googlesource.com/c/154381 Run-TryBot: Joel Sing TryBot-Result: Gobot Gobot Reviewed-by: Ian Lance Taylor --- src/cmd/dist/build.go | 2 +- src/cmd/dist/main.go | 7 ++++ src/cmd/link/internal/ld/lib.go | 6 +++ src/runtime/cgo/gcc_openbsd_arm.c | 67 +++++++++++++++++++++++++++++++ src/runtime/sys_openbsd_arm.s | 7 ++-- 5 files changed, 85 insertions(+), 4 deletions(-) create mode 100644 src/runtime/cgo/gcc_openbsd_arm.c diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go index 8d7b14d17c..da677c81ad 100644 --- a/src/cmd/dist/build.go +++ b/src/cmd/dist/build.go @@ -1448,7 +1448,7 @@ var cgoEnabled = map[string]bool{ "netbsd/arm": true, "openbsd/386": true, "openbsd/amd64": true, - "openbsd/arm": false, + "openbsd/arm": true, "plan9/386": false, "plan9/amd64": false, "plan9/arm": false, diff --git a/src/cmd/dist/main.go b/src/cmd/dist/main.go index bf08869afb..bab8ab781a 100644 --- a/src/cmd/dist/main.go +++ b/src/cmd/dist/main.go @@ -65,6 +65,13 @@ func main() { case "freebsd": // Since FreeBSD 10 gcc is no longer part of the base system. defaultclang = true + case "openbsd": + // The gcc available on OpenBSD armv7 is old/inadequate (for example, lacks + // __sync_fetch_and_*/__sync_*_and_fetch) and will likely be removed in the + // not-to-distant future - use clang instead. + if runtime.GOARCH == "arm" { + defaultclang = true + } case "solaris": // Even on 64-bit platform, solaris uname -m prints i86pc. out := run("", CheckExit, "isainfo", "-n") diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go index 253a9f6847..b45397e727 100644 --- a/src/cmd/link/internal/ld/lib.go +++ b/src/cmd/link/internal/ld/lib.go @@ -535,6 +535,12 @@ func (ctxt *Link) loadlib() { if *flagLibGCC == "" { *flagLibGCC = ctxt.findLibPathCmd("--print-libgcc-file-name", "libgcc") } + if runtime.GOOS == "openbsd" && *flagLibGCC == "libgcc.a" { + // On OpenBSD `clang --print-libgcc-file-name` returns "libgcc.a". + // In this case we fail to load libgcc.a and can encounter link + // errors - see if we can find libcompiler_rt.a instead. + *flagLibGCC = ctxt.findLibPathCmd("--print-file-name=libcompiler_rt.a", "libcompiler_rt") + } if *flagLibGCC != "none" { hostArchive(ctxt, *flagLibGCC) } diff --git a/src/runtime/cgo/gcc_openbsd_arm.c b/src/runtime/cgo/gcc_openbsd_arm.c new file mode 100644 index 0000000000..9a5757f0ad --- /dev/null +++ b/src/runtime/cgo/gcc_openbsd_arm.c @@ -0,0 +1,67 @@ +// Copyright 2018 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 +#include +#include +#include +#include "libcgo.h" +#include "libcgo_unix.h" + +static void* threadentry(void*); +static void (*setg_gcc)(void*); + +void +x_cgo_init(G *g, void (*setg)(void*)) +{ + pthread_attr_t attr; + size_t size; + + setg_gcc = setg; + pthread_attr_init(&attr); + pthread_attr_getstacksize(&attr, &size); + g->stacklo = (uintptr)&attr - size + 4096; + pthread_attr_destroy(&attr); +} + +void +_cgo_sys_thread_start(ThreadStart *ts) +{ + pthread_attr_t attr; + sigset_t ign, oset; + pthread_t p; + size_t size; + int err; + + sigfillset(&ign); + pthread_sigmask(SIG_SETMASK, &ign, &oset); + + pthread_attr_init(&attr); + pthread_attr_getstacksize(&attr, &size); + + // Leave stacklo=0 and set stackhi=size; mstart will do the rest. + ts->g->stackhi = size; + err = _cgo_try_pthread_create(&p, &attr, threadentry, ts); + + pthread_sigmask(SIG_SETMASK, &oset, nil); + + if (err != 0) { + fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err)); + abort(); + } +} + +extern void crosscall_arm1(void (*fn)(void), void (*setg_gcc)(void*), void *g); + +static void* +threadentry(void *v) +{ + ThreadStart ts; + + ts = *(ThreadStart*)v; + free(v); + + crosscall_arm1(ts.fn, setg_gcc, (void*)ts.g); + return nil; +} diff --git a/src/runtime/sys_openbsd_arm.s b/src/runtime/sys_openbsd_arm.s index 52d3638bc1..94ac5d599d 100644 --- a/src/runtime/sys_openbsd_arm.s +++ b/src/runtime/sys_openbsd_arm.s @@ -371,8 +371,9 @@ TEXT runtime·closeonexec(SB),NOSPLIT,$0 TEXT ·publicationBarrier(SB),NOSPLIT|NOFRAME,$0-0 B runtime·armPublicationBarrier(SB) -// TODO(jsing): Implement. TEXT runtime·read_tls_fallback(SB),NOSPLIT|NOFRAME,$0 - MOVW $5, R0 - MOVW R0, (R0) + MOVM.WP [R1, R2, R3, R12], (R13) + MOVW $330, R12 // sys___get_tcb + SWI $0 + MOVM.IAW (R13), [R1, R2, R3, R12] RET -- 2.48.1