On Tue, Nov 29, 2022 at 9:54 AM <soe...@soeren-tempel.net> wrote: > > From: Sören Tempel <soe...@soeren-tempel.net> > > On glibc, there are two versions of strerror_r: An XSI-compliant and a > GNU-specific version. The latter is only available on glibc. In order > to avoid duplicating the post-processing code of error messages, this > commit provides a separate strerror_go symbol which always refers to the > XSI-compliant version of strerror_r (even on glibc) by selectively > undefining the corresponding feature test macro. > > Previously, gofrontend assumed that the GNU-specific version of > strerror_r was always available on Linux (which isn't the case when > using a musl as a libc, for example). This commit thereby improves > compatibility with Linux systems that are not using glibc. > > Tested on x86_64 Alpine Linux Edge and Arch Linux (glibc 2.36).
Thanks. I committed a version of this, as attached. Ian
b6c6a3d64f2e4e9347733290aca3c75898c44b2e diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 7e531c3f90b..984d8324004 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -5e658f4659c551330ea68f5667e4f951b218f32d +fef6aa3c1678cdbe7dca454b2cebb369d8ba81bf The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/libgo/Makefile.am b/libgo/Makefile.am index b03e6553e90..207d5a98127 100644 --- a/libgo/Makefile.am +++ b/libgo/Makefile.am @@ -465,6 +465,7 @@ runtime_files = \ runtime/go-nanotime.c \ runtime/go-now.c \ runtime/go-nosys.c \ + runtime/go-strerror.c \ runtime/go-reflect-call.c \ runtime/go-setenv.c \ runtime/go-signal.c \ diff --git a/libgo/go/syscall/errstr.go b/libgo/go/syscall/errstr.go index 59f7a82c6d7..9f688e2a0c7 100644 --- a/libgo/go/syscall/errstr.go +++ b/libgo/go/syscall/errstr.go @@ -4,23 +4,19 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -//go:build !hurd && !linux -// +build !hurd,!linux - package syscall -//sysnb strerror_r(errnum int, buf []byte) (err Errno) -//strerror_r(errnum _C_int, buf *byte, buflen Size_t) _C_int +import "internal/bytealg" + +//extern go_strerror +func go_strerror(_C_int, *byte, Size_t) _C_int func Errstr(errnum int) string { - for len := 128; ; len *= 2 { - b := make([]byte, len) - errno := strerror_r(errnum, b) + for size := 128; ; size *= 2 { + b := make([]byte, size) + errno := go_strerror(_C_int(errnum), &b[0], Size_t(len(b))) if errno == 0 { - i := 0 - for b[i] != 0 { - i++ - } + i := bytealg.IndexByte(b, 0) // Lowercase first letter: Bad -> bad, but // STREAM -> STREAM. if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' { @@ -29,7 +25,7 @@ func Errstr(errnum int) string { return string(b[:i]) } if errno != ERANGE { - return "errstr failure" + return "strerror_r failure" } } } diff --git a/libgo/go/syscall/errstr_glibc.go b/libgo/go/syscall/errstr_glibc.go deleted file mode 100644 index 03a327dbc90..00000000000 --- a/libgo/go/syscall/errstr_glibc.go +++ /dev/null @@ -1,34 +0,0 @@ -// errstr_glibc.go -- GNU/Linux and GNU/Hurd specific error strings. - -// Copyright 2010 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. - -// We use this rather than errstr.go because on GNU/Linux sterror_r -// returns a pointer to the error message, and may not use buf at all. - -//go:build hurd || linux -// +build hurd linux - -package syscall - -import "unsafe" - -//sysnb strerror_r(errnum int, b []byte) (errstr *byte) -//strerror_r(errnum _C_int, b *byte, len Size_t) *byte - -func Errstr(errnum int) string { - a := make([]byte, 128) - p := strerror_r(errnum, a) - b := (*[1000]byte)(unsafe.Pointer(p)) - i := 0 - for b[i] != 0 { - i++ - } - // Lowercase first letter: Bad -> bad, but STREAM -> STREAM. - if i > 1 && 'A' <= b[0] && b[0] <= 'Z' && 'a' <= b[1] && b[1] <= 'z' { - c := b[0] + 'a' - 'A' - return string(c) + string(b[1:i]) - } - return string(b[:i]) -} diff --git a/libgo/runtime/go-strerror.c b/libgo/runtime/go-strerror.c new file mode 100644 index 00000000000..13d1d91df84 --- /dev/null +++ b/libgo/runtime/go-strerror.c @@ -0,0 +1,37 @@ +/* go-strerror.c -- wrapper around XSI-compliant strerror_r. + + Copyright 2022 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. */ + +/* There are two version of strerror_r on GNU/Linux: a GNU-specific + and an XSI-compliant version. The former version is only available + on glibc. Since glibc 2.13, the XSI-compliant version is also + provided by glibc if _GNU_SOURCE is not defined. Since the + entirety of gofrontend is compiled with _GNU_SOURCE, this file + exists to selectively undefine it and provides an alias to the + XSI-compliant version of strerror_r(3). */ + +#ifdef __linux__ + +/* Force selection of XSI-compliant strerror_r by glibc. */ +#undef XOPEN_SOURCE +#define XOPEN_SOURCE 600 +#undef _POSIX_C_SOURCE +#define _POSIX_C_SOURCE 200112L +#undef _GNU_SOURCE + +#endif /* __linux__ */ + +#include <string.h> + +#ifndef HAVE_STRERROR_R +// Provided by go-nosys.c if not provided by libc itself. +extern int strerror_r (int, char *, size_t); +#endif + +int +go_strerror (int errnum, char *buf, size_t buflen) +{ + return strerror_r (errnum, buf, buflen); +}