Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 195 insertions, 0 deletions

diff --git a/gcc-4.9/libgo/runtime/go-cgo.c b/gcc-4.9/libgo/runtime/go-cgo.c
new file mode 100644
index 000000000..9ba1ea7d0
--- /dev/null
+++ b/gcc-4.9/libgo/runtime/go-cgo.c
@@ -0,0 +1,195 @@
+/* go-cgo.c -- SWIG support routines for libgo.
+
+   Copyright 2011 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 "runtime.h"
+#include "go-alloc.h"
+#include "interface.h"
+#include "go-panic.h"
+
+/* Prepare to call from code written in Go to code written in C or
+   C++.  This takes the current goroutine out of the Go scheduler, as
+   though it were making a system call.  Otherwise the program can
+   lock up if the C code goes to sleep on a mutex or for some other
+   reason.  This idea is to call this function, then immediately call
+   the C/C++ function.  After the C/C++ function returns, call
+   syscall_cgocalldone.  The usual Go code would look like
+
+       syscall.Cgocall()
+       defer syscall.Cgocalldone()
+       cfunction()
+
+   */
+
+/* We let Go code call these via the syscall package.  */
+void syscall_cgocall(void) __asm__ (GOSYM_PREFIX "syscall.Cgocall");
+void syscall_cgocalldone(void) __asm__ (GOSYM_PREFIX "syscall.CgocallDone");
+void syscall_cgocallback(void) __asm__ (GOSYM_PREFIX "syscall.CgocallBack");
+void syscall_cgocallbackdone(void) __asm__ (GOSYM_PREFIX "syscall.CgocallBackDone");
+
+void
+syscall_cgocall ()
+{
+  M* m;
+  G* g;
+
+  if (runtime_needextram && runtime_cas (&runtime_needextram, 1, 0))
+    runtime_newextram ();
+
+  m = runtime_m ();
+  ++m->ncgocall;
+  g = runtime_g ();
+  ++g->ncgo;
+  runtime_entersyscall ();
+}
+
+/* Prepare to return to Go code from C/C++ code.  */
+
+void
+syscall_cgocalldone ()
+{
+  G* g;
+
+  g = runtime_g ();
+  __go_assert (g != NULL);
+  --g->ncgo;
+  if (g->ncgo == 0)
+    {
+      /* We are going back to Go, and we are not in a recursive call.
+	 Let the garbage collector clean up any unreferenced
+	 memory.  */
+      g->cgomal = NULL;
+    }
+
+  /* If we are invoked because the C function called _cgo_panic, then
+     _cgo_panic will already have exited syscall mode.  */
+  if (g->status == Gsyscall)
+    runtime_exitsyscall ();
+}
+
+/* Call back from C/C++ code to Go code.  */
+
+void
+syscall_cgocallback ()
+{
+  M *mp;
+
+  mp = runtime_m ();
+  if (mp == NULL)
+    {
+      runtime_needm ();
+      mp = runtime_m ();
+      mp->dropextram = true;
+    }
+
+  runtime_exitsyscall ();
+
+  mp = runtime_m ();
+  if (mp->needextram)
+    {
+      mp->needextram = 0;
+      runtime_newextram ();
+    }
+}
+
+/* Prepare to return to C/C++ code from a callback to Go code.  */
+
+void
+syscall_cgocallbackdone ()
+{
+  M *mp;
+
+  runtime_entersyscall ();
+  mp = runtime_m ();
+  if (mp->dropextram && runtime_g ()->ncgo == 0)
+    {
+      mp->dropextram = false;
+      runtime_dropm ();
+    }
+}
+
+/* Allocate memory and save it in a list visible to the Go garbage
+   collector.  */
+
+void *
+alloc_saved (size_t n)
+{
+  void *ret;
+  G *g;
+  CgoMal *c;
+
+  ret = __go_alloc (n);
+
+  g = runtime_g ();
+  c = (CgoMal *) __go_alloc (sizeof (CgoMal));
+  c->next = g->cgomal;
+  c->alloc = ret;
+  g->cgomal = c;
+
+  return ret;
+}
+
+/* These are routines used by SWIG.  The gc runtime library provides
+   the same routines under the same name, though in that case the code
+   is required to import runtime/cgo.  */
+
+void *
+_cgo_allocate (size_t n)
+{
+  void *ret;
+
+  runtime_exitsyscall ();
+  ret = alloc_saved (n);
+  runtime_entersyscall ();
+  return ret;
+}
+
+extern const struct __go_type_descriptor string_type_descriptor
+  __asm__ (GOSYM_PREFIX "__go_tdn_string");
+
+void
+_cgo_panic (const char *p)
+{
+  intgo len;
+  unsigned char *data;
+  String *ps;
+  struct __go_empty_interface e;
+
+  runtime_exitsyscall ();
+  len = __builtin_strlen (p);
+  data = alloc_saved (len);
+  __builtin_memcpy (data, p, len);
+  ps = alloc_saved (sizeof *ps);
+  ps->str = data;
+  ps->len = len;
+  e.__type_descriptor = &string_type_descriptor;
+  e.__object = ps;
+
+  /* We don't call runtime_entersyscall here, because normally what
+     will happen is that we will walk up the stack to a Go deferred
+     function that calls recover.  However, this will do the wrong
+     thing if this panic is recovered and the stack unwinding is
+     caught by a C++ exception handler.  It might be possible to
+     handle this by calling runtime_entersyscall in the personality
+     function in go-unwind.c.  FIXME.  */
+
+  __go_panic (e);
+}
+
+/* Return the number of CGO calls.  */
+
+int64 runtime_NumCgoCall (void) __asm__ (GOSYM_PREFIX "runtime.NumCgoCall");
+
+int64
+runtime_NumCgoCall (void)
+{
+  int64 ret;
+  M* m;
+
+  ret = 0;
+  for (m = runtime_atomicloadp (&runtime_allm); m != NULL; m = m->alllink)
+    ret += m->ncgocall;
+  return ret;
+}