syscall, runtime: always call XSI strerror_r

This does the right thing for either glibc or musl on GNU/Linux.

Based on patch by Sören Tempel.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/454176

diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 7e531c3f90b826fa476937b2c8a7e8300285a8e1..984d8324004e25064f98541c2fb1cf143a4be56f 100644 (file)
--- 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 b03e6553e909d593ed6d768cce1ec06f1c057352..207d5a9812768095ee7e3cd1c4ad982a343f6858 100644 (file)
--- 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/Makefile.in b/libgo/Makefile.in
index 16ed62a82edc709afc285f69c96846b3d0d078ae..0ff6ff4a5c5250f8db2a4c3d07a524f8d32a8fad 100644 (file)
--- a/libgo/Makefile.in
+++ b/libgo/Makefile.in
@@ -247,7 +247,7 @@ am__objects_4 = runtime/aeshash.lo runtime/go-assert.lo \
        runtime/go-fieldtrack.lo runtime/go-matherr.lo \
        runtime/go-memclr.lo runtime/go-memmove.lo \
        runtime/go-memequal.lo runtime/go-nanotime.lo \
-       runtime/go-now.lo runtime/go-nosys.lo \
+       runtime/go-now.lo runtime/go-nosys.lo runtime/go-strerror.lo \
        runtime/go-reflect-call.lo runtime/go-setenv.lo \
        runtime/go-signal.lo runtime/go-unsafe-pointer.lo \
        runtime/go-unsetenv.lo runtime/go-unwind.lo \
@@ -917,6 +917,7 @@ 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 \
@@ -1390,6 +1391,8 @@ runtime/go-now.lo: runtime/$(am__dirstamp) \
        runtime/$(DEPDIR)/$(am__dirstamp)
 runtime/go-nosys.lo: runtime/$(am__dirstamp) \
        runtime/$(DEPDIR)/$(am__dirstamp)
+runtime/go-strerror.lo: runtime/$(am__dirstamp) \
+       runtime/$(DEPDIR)/$(am__dirstamp)
 runtime/go-reflect-call.lo: runtime/$(am__dirstamp) \
        runtime/$(DEPDIR)/$(am__dirstamp)
 runtime/go-setenv.lo: runtime/$(am__dirstamp) \
@@ -1457,6 +1460,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-reflect-call.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-setenv.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-signal.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-strerror.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-unsafe-pointer.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-unsetenv.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@runtime/$(DEPDIR)/go-unwind.Plo@am__quote@

diff --git a/libgo/go/syscall/errstr.go b/libgo/go/syscall/errstr.go
index 59f7a82c6d73e4b3c11033bb75a2669ce0e25b92..9f688e2a0c7b8750a757618e5df775652b8e44e2 100644 (file)
--- 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 (file)
index 03a327d..0000000
--- 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 (file)
index 0000000..13d1d91
--- /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);
+}