[GCC 4.8] Initial check-in of GCC 4.8.0

Change-Id: I0719d8a6d0f69b367a6ab6f10eb75622dbf12771

1 files changed, 440 insertions, 0 deletions

diff --git a/gcc-4.8/libgo/runtime/go-unwind.c b/gcc-4.8/libgo/runtime/go-unwind.c
new file mode 100644
index 000000000..c669a3ce8
--- /dev/null
+++ b/gcc-4.8/libgo/runtime/go-unwind.c
@@ -0,0 +1,440 @@
+/* go-unwind.c -- unwind the stack for panic/recover.
+
+   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.  */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "unwind.h"
+#define NO_SIZE_OF_ENCODED_VALUE
+#include "unwind-pe.h"
+
+#include "runtime.h"
+#include "go-alloc.h"
+#include "go-defer.h"
+#include "go-panic.h"
+
+/* The code for a Go exception.  */
+
+#ifdef __ARM_EABI_UNWINDER__
+static const _Unwind_Exception_Class __go_exception_class =
+  { 'G', 'N', 'U', 'C', 'G', 'O', '\0', '\0' };
+#else
+static const _Unwind_Exception_Class __go_exception_class =
+  ((((((((_Unwind_Exception_Class) 'G' 
+         << 8 | (_Unwind_Exception_Class) 'N')
+        << 8 | (_Unwind_Exception_Class) 'U')
+       << 8 | (_Unwind_Exception_Class) 'C')
+      << 8 | (_Unwind_Exception_Class) 'G')
+     << 8 | (_Unwind_Exception_Class) 'O')
+    << 8 | (_Unwind_Exception_Class) '\0')
+   << 8 | (_Unwind_Exception_Class) '\0');
+#endif
+
+
+/* This function is called by exception handlers used when unwinding
+   the stack after a recovered panic.  The exception handler looks
+   like this:
+     __go_check_defer (frame);
+     return;
+   If we have not yet reached the frame we are looking for, we
+   continue unwinding.  */
+
+void
+__go_check_defer (_Bool *frame)
+{
+  G *g;
+  struct _Unwind_Exception *hdr;
+
+  g = runtime_g ();
+
+  if (g == NULL)
+    {
+      /* Some other language has thrown an exception.  We know there
+	 are no defer handlers, so there is nothing to do.  */
+    }
+  else if (g->is_foreign)
+    {
+      struct __go_panic_stack *n;
+      _Bool was_recovered;
+
+      /* Some other language has thrown an exception.  We need to run
+	 the local defer handlers.  If they call recover, we stop
+	 unwinding the stack here.  */
+
+      n = ((struct __go_panic_stack *)
+	   __go_alloc (sizeof (struct __go_panic_stack)));
+
+      n->__arg.__type_descriptor = NULL;
+      n->__arg.__object = NULL;
+      n->__was_recovered = 0;
+      n->__is_foreign = 1;
+      n->__next = g->panic;
+      g->panic = n;
+
+      while (1)
+	{
+	  struct __go_defer_stack *d;
+	  void (*pfn) (void *);
+
+	  d = g->defer;
+	  if (d == NULL || d->__frame != frame || d->__pfn == NULL)
+	    break;
+
+	  pfn = d->__pfn;
+	  g->defer = d->__next;
+
+	  (*pfn) (d->__arg);
+
+	  __go_free (d);
+
+	  if (n->__was_recovered)
+	    {
+	      /* The recover function caught the panic thrown by some
+		 other language.  */
+	      break;
+	    }
+	}
+
+      was_recovered = n->__was_recovered;
+      g->panic = n->__next;
+      __go_free (n);
+
+      if (was_recovered)
+	{
+	  /* Just return and continue executing Go code.  */
+	  *frame = 1;
+	  return;
+	}
+
+      /* We are panicing through this function.  */
+      *frame = 0;
+    }
+  else if (g->defer != NULL
+	   && g->defer->__pfn == NULL
+	   && g->defer->__frame == frame)
+    {
+      struct __go_defer_stack *d;
+
+      /* This is the defer function which called recover.  Simply
+	 return to stop the stack unwind, and let the Go code continue
+	 to execute.  */
+      d = g->defer;
+      g->defer = d->__next;
+      __go_free (d);
+
+      /* We are returning from this function.  */
+      *frame = 1;
+
+      return;
+    }
+
+  /* This is some other defer function.  It was already run by the
+     call to panic, or just above.  Rethrow the exception.  */
+
+  hdr = (struct _Unwind_Exception *) g->exception;
+
+#ifdef LIBGO_SJLJ_EXCEPTIONS
+  _Unwind_SjLj_Resume_or_Rethrow (hdr);
+#else
+#if defined(_LIBUNWIND_STD_ABI)
+  _Unwind_RaiseException (hdr);
+#else
+  _Unwind_Resume_or_Rethrow (hdr);
+#endif
+#endif
+
+  /* Rethrowing the exception should not return.  */
+  abort();
+}
+
+/* Unwind function calls until we reach the one which used a defer
+   function which called recover.  Each function which uses a defer
+   statement will have an exception handler, as shown above.  */
+
+void
+__go_unwind_stack ()
+{
+  struct _Unwind_Exception *hdr;
+
+  hdr = ((struct _Unwind_Exception *)
+	 __go_alloc (sizeof (struct _Unwind_Exception)));
+  __builtin_memcpy (&hdr->exception_class, &__go_exception_class,
+		    sizeof hdr->exception_class);
+  hdr->exception_cleanup = NULL;
+
+  runtime_g ()->exception = hdr;
+
+#ifdef __USING_SJLJ_EXCEPTIONS__
+  _Unwind_SjLj_RaiseException (hdr);
+#else
+  _Unwind_RaiseException (hdr);
+#endif
+
+  /* Raising an exception should not return.  */
+  abort ();
+}
+
+/* The rest of this code is really similar to gcc/unwind-c.c and
+   libjava/exception.cc.  */
+
+typedef struct
+{
+  _Unwind_Ptr Start;
+  _Unwind_Ptr LPStart;
+  _Unwind_Ptr ttype_base;
+  const unsigned char *TType;
+  const unsigned char *action_table;
+  unsigned char ttype_encoding;
+  unsigned char call_site_encoding;
+} lsda_header_info;
+
+static const unsigned char *
+parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p,
+		   lsda_header_info *info)
+{
+  _uleb128_t tmp;
+  unsigned char lpstart_encoding;
+
+  info->Start = (context ? _Unwind_GetRegionStart (context) : 0);
+
+  /* Find @LPStart, the base to which landing pad offsets are relative.  */
+  lpstart_encoding = *p++;
+  if (lpstart_encoding != DW_EH_PE_omit)
+    p = read_encoded_value (context, lpstart_encoding, p, &info->LPStart);
+  else
+    info->LPStart = info->Start;
+
+  /* Find @TType, the base of the handler and exception spec type data.  */
+  info->ttype_encoding = *p++;
+  if (info->ttype_encoding != DW_EH_PE_omit)
+    {
+      p = read_uleb128 (p, &tmp);
+      info->TType = p + tmp;
+    }
+  else
+    info->TType = 0;
+
+  /* The encoding and length of the call-site table; the action table
+     immediately follows.  */
+  info->call_site_encoding = *p++;
+  p = read_uleb128 (p, &tmp);
+  info->action_table = p + tmp;
+
+  return p;
+}
+
+/* The personality function is invoked when unwinding the stack due to
+   a panic.  Its job is to find the cleanup and exception handlers to
+   run.  We can't split the stack here, because we won't be able to
+   unwind from that split.  */
+
+#ifdef __ARM_EABI_UNWINDER__
+/* ARM EABI personality routines must also unwind the stack.  */
+#define CONTINUE_UNWINDING \
+  do								\
+    {								\
+      if (__gnu_unwind_frame (ue_header, context) != _URC_OK)	\
+	return _URC_FAILURE;					\
+      return _URC_CONTINUE_UNWIND;				\
+    }								\
+  while (0)
+#else
+#define CONTINUE_UNWINDING return _URC_CONTINUE_UNWIND
+#endif
+
+#ifdef __USING_SJLJ_EXCEPTIONS__
+#define PERSONALITY_FUNCTION    __gccgo_personality_sj0
+#define __builtin_eh_return_data_regno(x) x
+#else
+#define PERSONALITY_FUNCTION    __gccgo_personality_v0
+#endif
+
+#ifdef __ARM_EABI_UNWINDER__
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (_Unwind_State, struct _Unwind_Exception *,
+		      struct _Unwind_Context *)
+  __attribute__ ((no_split_stack, flatten));
+
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (_Unwind_State state,
+		      struct _Unwind_Exception * ue_header,
+		      struct _Unwind_Context * context)
+#else
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (int, _Unwind_Action, _Unwind_Exception_Class,
+		      struct _Unwind_Exception *, struct _Unwind_Context *)
+  __attribute__ ((no_split_stack, flatten));
+
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (int version,
+		      _Unwind_Action actions,
+		      _Unwind_Exception_Class exception_class,
+		      struct _Unwind_Exception *ue_header,
+		      struct _Unwind_Context *context)
+#endif
+{
+  lsda_header_info info;
+  const unsigned char *language_specific_data, *p, *action_record;
+  _Unwind_Ptr landing_pad, ip;
+  int ip_before_insn = 0;
+  _Bool is_foreign;
+  G *g;
+
+#ifdef __ARM_EABI_UNWINDER__
+  _Unwind_Action actions;
+
+  switch (state & _US_ACTION_MASK)
+    {
+    case _US_VIRTUAL_UNWIND_FRAME:
+      actions = _UA_SEARCH_PHASE;
+      break;
+
+    case _US_UNWIND_FRAME_STARTING:
+      actions = _UA_CLEANUP_PHASE;
+      if (!(state & _US_FORCE_UNWIND)
+	  && ue_header->barrier_cache.sp == _Unwind_GetGR(context, 13))
+	actions |= _UA_HANDLER_FRAME;
+      break;
+
+    case _US_UNWIND_FRAME_RESUME:
+      CONTINUE_UNWINDING;
+      break;
+
+    default:
+      abort();
+    }
+  actions |= state & _US_FORCE_UNWIND;
+
+  is_foreign = 0;
+
+  /* The dwarf unwinder assumes the context structure holds things like the
+     function and LSDA pointers.  The ARM implementation caches these in
+     the exception header (UCB).  To avoid rewriting everything we make the
+     virtual IP register point at the UCB.  */
+  ip = (_Unwind_Ptr) ue_header;
+  _Unwind_SetGR (context, 12, ip);
+#else
+  if (version != 1)
+    return _URC_FATAL_PHASE1_ERROR;
+
+  is_foreign = exception_class != __go_exception_class;
+#endif
+
+  language_specific_data = (const unsigned char *)
+    _Unwind_GetLanguageSpecificData (context);
+
+  /* If no LSDA, then there are no handlers or cleanups.  */
+  if (! language_specific_data)
+    CONTINUE_UNWINDING;
+
+  /* Parse the LSDA header.  */
+  p = parse_lsda_header (context, language_specific_data, &info);
+#ifdef HAVE_GETIPINFO
+  ip = _Unwind_GetIPInfo (context, &ip_before_insn);
+#else
+  ip = _Unwind_GetIP (context);
+#endif
+  if (! ip_before_insn)
+    --ip;
+  landing_pad = 0;
+  action_record = NULL;
+
+#ifdef __USING_SJLJ_EXCEPTIONS__
+  /* The given "IP" is an index into the call-site table, with two
+     exceptions -- -1 means no-action, and 0 means terminate.  But
+     since we're using uleb128 values, we've not got random access
+     to the array.  */
+  if ((int) ip <= 0)
+    return _URC_CONTINUE_UNWIND;
+  else
+    {
+      _uleb128_t cs_lp, cs_action;
+      do
+	{
+	  p = read_uleb128 (p, &cs_lp);
+	  p = read_uleb128 (p, &cs_action);
+	}
+      while (--ip);
+
+      /* Can never have null landing pad for sjlj -- that would have
+	 been indicated by a -1 call site index.  */
+      landing_pad = (_Unwind_Ptr)cs_lp + 1;
+      if (cs_action)
+	action_record = info.action_table + cs_action - 1;
+      goto found_something;
+    }
+#else
+  /* Search the call-site table for the action associated with this IP.  */
+  while (p < info.action_table)
+    {
+      _Unwind_Ptr cs_start, cs_len, cs_lp;
+      _uleb128_t cs_action;
+
+      /* Note that all call-site encodings are "absolute" displacements.  */
+      p = read_encoded_value (0, info.call_site_encoding, p, &cs_start);
+      p = read_encoded_value (0, info.call_site_encoding, p, &cs_len);
+      p = read_encoded_value (0, info.call_site_encoding, p, &cs_lp);
+      p = read_uleb128 (p, &cs_action);
+
+      /* The table is sorted, so if we've passed the ip, stop.  */
+      if (ip < info.Start + cs_start)
+	p = info.action_table;
+      else if (ip < info.Start + cs_start + cs_len)
+	{
+	  if (cs_lp)
+	    landing_pad = info.LPStart + cs_lp;
+	  if (cs_action)
+	    action_record = info.action_table + cs_action - 1;
+	  goto found_something;
+	}
+    }
+#endif
+
+  /* IP is not in table.  No associated cleanups.  */
+  CONTINUE_UNWINDING;
+
+ found_something:
+  if (landing_pad == 0)
+    {
+      /* IP is present, but has a null landing pad.
+	 No handler to be run.  */
+      CONTINUE_UNWINDING;
+    }
+
+  if (actions & _UA_SEARCH_PHASE)
+    {
+      if (action_record == 0)
+	{
+	  /* This indicates a cleanup rather than an exception
+	     handler.  */
+	  CONTINUE_UNWINDING;
+	}
+
+      return _URC_HANDLER_FOUND;
+    }
+
+  /* It's possible for g to be NULL here for an exception thrown by a
+     language other than Go.  */
+  g = runtime_g ();
+  if (g == NULL)
+    {
+      if (!is_foreign)
+	abort ();
+    }
+  else
+    {
+      g->exception = ue_header;
+      g->is_foreign = is_foreign;
+    }
+
+  _Unwind_SetGR (context, __builtin_eh_return_data_regno (0),
+		 (_Unwind_Ptr) ue_header);
+  _Unwind_SetGR (context, __builtin_eh_return_data_regno (1), 0);
+  _Unwind_SetIP (context, landing_pad);
+  return _URC_INSTALL_CONTEXT;
+}