Merge from trunk revision aa8f4242efc99f24de73c59d53996f28db28c13f.

11 files changed, 157 insertions, 57 deletions

diff --git a/libgo/Makefile.am b/libgo/Makefile.am
index b03e655..207d5a9 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/Makefile.in b/libgo/Makefile.in
index 16ed62a..0ff6ff4 100644
--- 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/configure b/libgo/configure
index 61a4994..a607dbf 100755
--- a/libgo/configure
+++ b/libgo/configure
@@ -2608,7 +2608,7 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 ac_config_headers="$ac_config_headers config.h"
 
 
-libtool_VERSION=21:0:0
+libtool_VERSION=22:0:0
 
 
 # Default to --enable-multilib
@@ -14818,6 +14818,63 @@ fi
 
 
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing makecontext" >&5
+$as_echo_n "checking for library containing makecontext... " >&6; }
+if ${ac_cv_search_makecontext+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char makecontext ();
+int
+main ()
+{
+return makecontext ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' ucontext; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_search_makecontext=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if ${ac_cv_search_makecontext+:} false; then :
+  break
+fi
+done
+if ${ac_cv_search_makecontext+:} false; then :
+
+else
+  ac_cv_search_makecontext=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_makecontext" >&5
+$as_echo "$ac_cv_search_makecontext" >&6; }
+ac_res=$ac_cv_search_makecontext
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing sched_yield" >&5
 $as_echo_n "checking for library containing sched_yield... " >&6; }
 if ${ac_cv_search_sched_yield+:} false; then :
diff --git a/libgo/configure.ac b/libgo/configure.ac
index 274fcfc..a59aa09 100644
--- a/libgo/configure.ac
+++ b/libgo/configure.ac
@@ -10,7 +10,7 @@ AC_INIT(package-unused, version-unused,, libgo)
 AC_CONFIG_SRCDIR(Makefile.am)
 AC_CONFIG_HEADER(config.h)
 
-libtool_VERSION=21:0:0
+libtool_VERSION=22:0:0
 AC_SUBST(libtool_VERSION)
 
 AM_ENABLE_MULTILIB(, ..)
@@ -570,6 +570,9 @@ PTHREAD_LIBS=
 AC_CHECK_LIB([pthread], [pthread_create], PTHREAD_LIBS=-lpthread)
 AC_SUBST(PTHREAD_LIBS)
 
+dnl Test if -lucontext is required for makecontext.
+AC_SEARCH_LIBS([makecontext], [ucontext])
+
 dnl Test if -lrt is required for sched_yield or nanosleep or clock_gettime.
 AC_SEARCH_LIBS([sched_yield], [rt])
 AC_SEARCH_LIBS([nanosleep], [rt])
diff --git a/libgo/go/runtime/ffi.go b/libgo/go/runtime/ffi.go
index cd8479e..86ce5b8 100644
--- a/libgo/go/runtime/ffi.go
+++ b/libgo/go/runtime/ffi.go
@@ -4,6 +4,7 @@
 
 // Only build this file if libffi is supported.
 
+//go:build libffi
 // +build libffi
 
 package runtime
@@ -221,9 +222,6 @@ func stringToFFI() *__ffi_type {
 // structToFFI returns an ffi_type for a Go struct type.
 func structToFFI(typ *structtype) *__ffi_type {
 	c := len(typ.fields)
-	if c == 0 {
-		return emptyStructToFFI()
-	}
 	if typ.typ.kind&kindDirectIface != 0 {
 		return ffi_type_pointer()
 	}
@@ -231,6 +229,7 @@ func structToFFI(typ *structtype) *__ffi_type {
 	fields := make([]*__ffi_type, 0, c+1)
 	checkPad := false
 	lastzero := false
+	sawnonzero := false
 	for i, v := range typ.fields {
 		// Skip zero-sized fields; they confuse libffi,
 		// and there is no value to pass in any case.
@@ -239,10 +238,13 @@ func structToFFI(typ *structtype) *__ffi_type {
 		// next field.
 		if v.typ.size == 0 {
 			checkPad = true
-			lastzero = true
+			if v.name == nil || *v.name != "_" {
+				lastzero = true
+			}
 			continue
 		}
 		lastzero = false
+		sawnonzero = true
 
 		if checkPad {
 			off := uintptr(0)
@@ -263,6 +265,10 @@ func structToFFI(typ *structtype) *__ffi_type {
 		fields = append(fields, typeToFFI(v.typ))
 	}
 
+	if !sawnonzero {
+		return emptyStructToFFI()
+	}
+
 	if lastzero {
 		// The compiler adds one byte padding to non-empty struct ending
 		// with a zero-sized field (types.cc:get_backend_struct_fields).
diff --git a/libgo/go/runtime/mem_gccgo.go b/libgo/go/runtime/mem_gccgo.go
index fa3389d..1e84f4f 100644
--- a/libgo/go/runtime/mem_gccgo.go
+++ b/libgo/go/runtime/mem_gccgo.go
@@ -15,7 +15,7 @@ import (
 //go:linkname sysFree
 
 //extern mmap
-func sysMmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uintptr) unsafe.Pointer
+func sysMmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off _libgo_off_t_type) unsafe.Pointer
 
 //extern munmap
 func munmap(addr unsafe.Pointer, length uintptr) int32
@@ -38,7 +38,7 @@ func init() {
 }
 
 func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uintptr) (unsafe.Pointer, int) {
-	p := sysMmap(addr, n, prot, flags, fd, off)
+	p := sysMmap(addr, n, prot, flags, fd, _libgo_off_t_type(off))
 	if uintptr(p) == _MAP_FAILED {
 		return nil, errno()
 	}
@@ -47,6 +47,7 @@ func mmap(addr unsafe.Pointer, n uintptr, prot, flags, fd int32, off uintptr) (u
 
 // Don't split the stack as this method may be invoked without a valid G, which
 // prevents us from allocating more stack.
+//
 //go:nosplit
 func sysAlloc(n uintptr, sysStat *sysMemStat) unsafe.Pointer {
 	p, err := mmap(nil, n, _PROT_READ|_PROT_WRITE, _MAP_ANON|_MAP_PRIVATE, mmapFD, 0)
@@ -165,6 +166,7 @@ func sysHugePage(v unsafe.Pointer, n uintptr) {
 
 // Don't split the stack as this function may be invoked without a valid G,
 // which prevents us from allocating more stack.
+//
 //go:nosplit
 func sysFree(v unsafe.Pointer, n uintptr, sysStat *sysMemStat) {
 	sysStat.add(-int64(n))
diff --git a/libgo/go/runtime/os_linux.go b/libgo/go/runtime/os_linux.go
index 96fb178..2b2d827 100644
--- a/libgo/go/runtime/os_linux.go
+++ b/libgo/go/runtime/os_linux.go
@@ -22,6 +22,12 @@ type mOS struct {
 	profileTimerValid uint32
 }
 
+// setSigeventTID is written in C to set the sigev_notify_thread_id
+// field of a sigevent struct.
+//
+//go:noescape
+func setSigeventTID(*_sigevent, int32)
+
 func getProcID() uint64 {
 	return uint64(gettid())
 }
@@ -52,9 +58,12 @@ const (
 )
 
 // Atomically,
+//
 //	if(*addr == val) sleep
+//
 // Might be woken up spuriously; that's allowed.
 // Don't sleep longer than ns; ns < 0 means forever.
+//
 //go:nosplit
 func futexsleep(addr *uint32, val uint32, ns int64) {
 	// Some Linux kernels have a bug where futex of
@@ -73,6 +82,7 @@ func futexsleep(addr *uint32, val uint32, ns int64) {
 }
 
 // If any procs are sleeping on addr, wake up at most cnt.
+//
 //go:nosplit
 func futexwakeup(addr *uint32, cnt uint32) {
 	ret := futex(unsafe.Pointer(addr), _FUTEX_WAKE_PRIVATE, cnt, nil, nil, 0)
@@ -365,7 +375,7 @@ func setThreadCPUProfiler(hz int32) {
 	var sevp _sigevent
 	sevp.sigev_notify = _SIGEV_THREAD_ID
 	sevp.sigev_signo = _SIGPROF
-	*((*int32)(unsafe.Pointer(&sevp._sigev_un))) = int32(mp.procid)
+	setSigeventTID(&sevp, int32(mp.procid))
 	ret := timer_create(_CLOCK_THREAD_CPUTIME_ID, &sevp, &timerid)
 	if ret != 0 {
 		// If we cannot create a timer for this M, leave profileTimerValid false
diff --git a/libgo/go/syscall/errstr.go b/libgo/go/syscall/errstr.go
index 59f7a82..9f688e2 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 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-signal.c b/libgo/runtime/go-signal.c
index 528d9b6..aa1b630 100644
--- a/libgo/runtime/go-signal.c
+++ b/libgo/runtime/go-signal.c
@@ -183,6 +183,24 @@ setSigactionHandler(struct sigaction* sa, uintptr handler)
 	sa->sa_sigaction = (void*)(handler);
 }
 
+#ifdef __linux__
+
+// Workaround for https://sourceware.org/bugzilla/show_bug.cgi?id=27417
+#ifndef sigev_notify_thread_id
+  #define sigev_notify_thread_id _sigev_un._tid
+#endif
+
+void setSigeventTID(struct sigevent*, int32_t)
+	__asm__ (GOSYM_PREFIX "runtime.setSigeventTID");
+
+void
+setSigeventTID(struct sigevent *sev, int32_t v)
+{
+	sev->sigev_notify_thread_id = v;
+}
+
+#endif // defined(__linux__)
+
 // C code to fetch values from the siginfo_t and ucontext_t pointers
 // passed to a signal handler.
 
diff --git a/libgo/runtime/go-strerror.c b/libgo/runtime/go-strerror.c
new file mode 100644
index 0000000..8ff5ffb
--- /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).  */
+
+#if defined(__linux__) || defined(__gnu_hurd__)
+
+/* 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 /* defined(__linux__) || defined(__gnu_hurd__) */
+
+#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);
+}