diff -r 000000000000 -r a41df078684a kernel/eka/compsupp/symaehabi/unwind_pr.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/compsupp/symaehabi/unwind_pr.c	Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,840 @@
+/* unwind_pr.c - ARM-defined model personality routines
+ *
+ * Copyright 2002-2005 ARM Limited. All rights reserved.
+ *
+ * Your rights to use this code are set out in the accompanying licence
+ * text file LICENCE.txt (ARM contract number LEC-ELA-00080 v1.0).
+ */
+
+/* Portions copyright Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies). */
+
+/*
+ * RCS $Revision: 92986 $
+ * Checkin $Date: 2005-10-13 15:56:12 +0100 (Thu, 13 Oct 2005) $
+ * Revising $Author: achapman $
+ */
+
+#include <cstdlib>
+/* Environment: */
+#include "unwind_env.h"
+/* Language-independent unwinder declarations: */
+#include "unwinder.h"
+
+/* Define PR_DIAGNOSTICS for printed diagnostics from the personality routine */
+
+#ifdef __EPOC32__
+/* Symbian specific support */
+#include "symbian_support.h"
+#endif
+
+#ifdef PR_DIAGNOSTICS
+#ifndef __EPOC32__
+extern int printf(const char *, ...);
+#endif
+#endif
+
+
+/* Forward decl: */
+extern _Unwind_Reason_Code __ARM_unwind_cpp_prcommon(_Unwind_State state,
+                                                     _Unwind_Control_Block *ucbp,
+                                                     _Unwind_Context *context,
+                                                     uint32_t idx);
+
+/* Personality routines - external entry points.
+ * pr0: short unwind description, 16 bit EHT offsets.
+ * pr1: long unwind description, 16 bit EHT offsets.
+ * pr2: long unwind description, 32 bit EHT offsets.
+ */
+
+#ifdef pr0_c
+_Unwind_Reason_Code __aeabi_unwind_cpp_pr0(_Unwind_State state,
+                                           _Unwind_Control_Block *ucbp,
+                                           _Unwind_Context *context) {
+  return __ARM_unwind_cpp_prcommon(state, ucbp, context, 0);
+}
+#endif
+
+#ifdef pr1_c
+EXPORT_C _Unwind_Reason_Code __aeabi_unwind_cpp_pr1(_Unwind_State state,
+                                                    _Unwind_Control_Block *ucbp,
+                                                    _Unwind_Context *context) {
+  return __ARM_unwind_cpp_prcommon(state, ucbp, context, 1);
+}
+#endif
+
+#ifdef pr2_c
+EXPORT_C _Unwind_Reason_Code __aeabi_unwind_cpp_pr2(_Unwind_State state,
+                                                    _Unwind_Control_Block *ucbp,
+                                                    _Unwind_Context *context) {
+  return __ARM_unwind_cpp_prcommon(state, ucbp, context, 2);
+}
+#endif
+
+/* The rest of the file deals with the common routine */
+
+#ifdef prcommon_c
+
+/* C++ exceptions ABI required here:
+ * Declare protocol routines called by the personality routine.
+ * These are weak references so that referencing them here is
+ * insufficient to pull them into the image - they will only be
+ * included if application code uses a __cxa routine.
+ */
+
+typedef unsigned char bool;
+static const bool false = 0;
+static const bool true = !false;
+
+typedef struct _ZSt9type_info type_info; /* This names C++ type_info type */
+
+IMPORT_C WEAKDECL void __cxa_call_unexpected(_Unwind_Control_Block *ucbp);
+IMPORT_C WEAKDECL bool __cxa_begin_cleanup(_Unwind_Control_Block *ucbp);
+typedef enum {
+    ctm_failed = 0,
+    ctm_succeeded = 1,
+    ctm_succeeded_with_ptr_to_base = 2
+  } __cxa_type_match_result;
+IMPORT_C WEAKDECL __cxa_type_match_result __cxa_type_match(_Unwind_Control_Block *ucbp,
+                                                           const type_info *rttip,
+                                                           bool is_reference_type,
+                                                           void **matched_object);
+
+/* ----- Helper routines, private ----- */
+
+/* R_ARM_PREL31 is a place-relative 31-bit signed relocation.  The
+ * routine takes the address of a location that was relocated by
+ * R_ARM_PREL31, and returns an absolute address.
+ */
+static FORCEINLINE uint32_t __ARM_resolve_prel31(void *p)
+{
+  return (uint32_t)((((*(int32_t *)p) << 1) >> 1) + (int32_t)p);
+}
+
+/* --------- VRS manipulation: --------- */
+
+#define R_SP 13
+#define R_LR 14
+#define R_PC 15
+
+static FORCEINLINE uint32_t core_get(_Unwind_Context *context, uint32_t regno)
+{
+  uint32_t val;
+  /* This call is required to never fail if given a valid regno */
+  _Unwind_VRS_Get(context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
+  return val;
+}
+
+static FORCEINLINE void core_set(_Unwind_Context *context, uint32_t regno, uint32_t newval)
+{
+  /* This call is required to never fail if given a valid regno */
+  _Unwind_VRS_Set(context, _UVRSC_CORE, regno, _UVRSD_UINT32, &newval);
+}
+
+static FORCEINLINE uint32_t count_to_mask(uint32_t count) {
+  return (1 << count) - 1;
+}
+
+/* --------- Support for unwind instruction stream: --------- */
+
+#define CODE_FINISH (0xb0)
+
+typedef struct uwdata {
+  uint32_t unwind_word;                  /* current word of unwind description */
+  uint32_t *unwind_word_pointer;         /* ptr to next word */
+  uint8_t unwind_word_bytes_remaining;   /* count of bytes left in current word */
+  uint8_t unwind_words_remaining;        /* count of words left, at ptr onwards */
+} uwdata;
+
+static INLINE uint8_t next_unwind_byte(uwdata *u) {
+  uint8_t ub;
+  if (u->unwind_word_bytes_remaining == 0) {  /* Load another word */
+    if (u->unwind_words_remaining == 0) return CODE_FINISH; /* nothing left - yield NOP */
+    u->unwind_words_remaining--;
+    u->unwind_word = *(u->unwind_word_pointer++);
+    u->unwind_word_bytes_remaining = 4;
+  }
+  
+  u->unwind_word_bytes_remaining--;
+  ub = (u->unwind_word & 0xff000000) >> 24;
+  u->unwind_word <<= 8;
+  return ub;
+}
+
+
+/* --------- Personality routines: --------- */
+
+/* The C++ Standard is silent on what is supposed to happen if an internal
+ * inconsistency occurs during unwinding. In our design, we return to the
+ * caller with _URC_FAILURE. During phase 1 this causes a return from the
+ * language-independent unwinder to its caller (__cxa_throw or __cxa_rethrow)
+ * which will then call terminate(). If an error occurs during phase 2, the
+ * caller will call abort().
+ */
+
+/* Types to assist with reading EHT's */
+
+typedef struct {
+  uint16_t length;
+  uint16_t offset;
+} EHT16;
+
+typedef struct {
+  uint32_t length;
+  uint32_t offset;
+} EHT32;
+
+typedef uint32_t landingpad_t;
+
+typedef struct {
+  landingpad_t landingpad;
+} EHT_cleanup_tail;
+
+typedef struct {
+  landingpad_t landingpad;
+  uint32_t rtti_ref;
+} EHT_catch_tail;
+
+typedef struct {
+  uint32_t rtti_count;           /* table count (possibly 0) */
+  uint32_t (rtti_refs[1]);       /* variable length table, possibly followed by landing pad */
+} EHT_fnspec_tail;
+
+
+/* Macros: */
+
+/* Barrier cache: */
+/* Requirement imposed by C++ semantics module - pointer to match object in slot 0: */
+#define BARRIER_HANDLEROBJECT (0)
+/* Requirement imposed by C++ semantics module - function exception spec info */
+#define BARRIER_FNSPECCOUNT  (1)
+#define BARRIER_FNSPECBASE   (2)
+#define BARRIER_FNSPECSTRIDE (3)
+#define BARRIER_FNSPECARRAY  (4)
+/* Private use for us until catch handler entry complete: */
+#define BARRIER_TEMPORARYMATCHOBJECT (1)
+/* Private use for us between phase 1 & 2: */
+#define BARRIER_EHTP (2)
+
+#define SAVE_CATCH_PROPAGATION_BARRIER(UCB_PTR,VSP,EHTP,HANDLEROBJECT) \
+  (UCB_PTR)->barrier_cache.sp = (VSP);    \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_EHTP] = (uint32_t)(EHTP); \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_HANDLEROBJECT] = (uint32_t)(HANDLEROBJECT);
+
+#define SAVE_CATCH_OF_BASEPTR_PROPAGATION_BARRIER(UCB_PTR,VSP,EHTP,HANDLEROBJECT) \
+  (UCB_PTR)->barrier_cache.sp = (VSP);    \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_EHTP] = (uint32_t)(EHTP); \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_TEMPORARYMATCHOBJECT] = (uint32_t)(HANDLEROBJECT); \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_HANDLEROBJECT] = (uint32_t)&((UCB_PTR)->barrier_cache.bitpattern[BARRIER_TEMPORARYMATCHOBJECT]);
+
+#define SAVE_FNSPEC_PROPAGATION_BARRIER(UCB_PTR,VSP,EHTP) \
+  (UCB_PTR)->barrier_cache.sp = (VSP);    \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_EHTP] = (uint32_t)(EHTP); \
+  (UCB_PTR)->barrier_cache.bitpattern[BARRIER_HANDLEROBJECT] = (uint32_t)0;
+
+#define CHECK_FOR_PROPAGATION_BARRIER(UCB_PTR,VSP,EHTP) \
+   ((UCB_PTR)->barrier_cache.sp == (VSP) &&    \
+    (UCB_PTR)->barrier_cache.bitpattern[BARRIER_EHTP] == (uint32_t)(EHTP))
+
+
+/* Cleanup cache: We only use one field */
+#define CLEANUP_EHTP (0)
+
+
+/* Special catch rtti values */
+#define CATCH_ALL               (0xffffffff)
+#define CATCH_ALL_AND_TERMINATE (0xfffffffe)
+/* Landing pad bit for catching a reference type */
+#define CATCH_REFERENCE         (0x80000000)
+
+
+/* Common personality routine: receives pr index as an argument.
+ *
+ * Note this implementation contains no explicit check against attempting to
+ * unwind off the top of the stack. Instead it relies (in cooperation with
+ * the language-independent unwinder) on there being a propagation barrier
+ * somewhere on the stack, perhaps the caller to main being not
+ * unwindable. An alternative would be to check for the stack pointer
+ * addressing a stack limit symbol.
+ */
+
+_Unwind_Reason_Code __ARM_unwind_cpp_prcommon(_Unwind_State state,
+                                              _Unwind_Control_Block *ucbp,
+                                              _Unwind_Context *context,
+                                              uint32_t idx)
+{
+  _Unwind_EHT_Header *eht_startp;  /* EHT start pointer */
+  uint8_t *ehtp; /* EHT pointer, incremented as required */
+  /* Flag for fnspec violations in which the frame should be unwound before calling unexpected() */
+  bool phase2_call_unexpected_after_unwind;
+  /* Flag for whether we have loaded r15 (pc) with a return address while executing
+   * unwind instructions.
+   * Set this on any write to r15 while executing the unwind instructions.
+   */
+  bool wrote_pc = false;
+  /* Flag for whether we have loaded r14 (lr) with a return address while executing
+   * unwind instructions.
+   * Set this on any write to r14 while executing the unwind instructions.
+   */
+  bool wrote_lr = false;
+  /* Flag for whether we loaded r15 from r14 while executing the unwind instructions */
+  bool wrote_pc_from_lr = false;
+  uwdata ud;
+
+  /* Are we version 2 of the EHABI ? */
+  bool ehabiv2 = EHABI_V2(ucbp);
+
+  /* Mark all as well and extract the EHT pointer */
+
+  eht_startp = ucbp->pr_cache.ehtp;
+
+#ifdef PR_DIAGNOSTICS
+  printf("PR entered: state=%d, r15=0x%x, fnstart=0x%x\n",
+         state, core_get(context, R_PC), ucbp->pr_cache.fnstart);
+#endif
+  
+  /* What are we supposed to do? */
+
+  if (state != _US_VIRTUAL_UNWIND_FRAME &&
+      state != _US_UNWIND_FRAME_STARTING &&
+      state != _US_UNWIND_FRAME_RESUME) {
+    DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_UNSPECIFIED);
+    return _URC_FAILURE;
+  }
+
+  phase2_call_unexpected_after_unwind = false;
+
+  /* Traverse the current EHT, if there is one.
+   * The required behaviours are:
+   * _US_VIRTUAL_UNWIND_FRAME: search for a propagation barrier in this frame.
+   * otherwise look for the propagation barrier we found in phase 1,
+   * performing cleanups on the way. In this case if state will be one of:
+   *   _US_UNWIND_FRAME_STARTING  first time with this frame
+   *   _US_UNWIND_FRAME_RESUME    not first time, we are part-way through the EHT.
+   */
+  
+  if ((ucbp->pr_cache.additional & 1) == 0) { /* EHT inline in index table? */
+    /* No: thus there is a real EHT */
+    
+    if (state == _US_UNWIND_FRAME_RESUME) {
+      /* Recover saved pointer to next EHT entry */
+      ehtp = (uint8_t *)ucbp->cleanup_cache.bitpattern[CLEANUP_EHTP];
+#ifdef PR_DIAGNOSTICS
+      printf("PR EHT recovered pointer 0x%x\n", (int)ehtp);
+#endif
+    } else {
+      /* Point at the first EHT entry.
+       * For pr0, the unwind description is entirely within the header word.
+       * For pr1 & pr2, an unwind description extension word count is
+       * held in bits 16-23 of the header word.
+       */
+      uint32_t unwind_extension_word_count = (idx == 0 ? 0 : ((*eht_startp) >> 16) & 0xff);
+      ehtp = (uint8_t *)(eht_startp + 1 + unwind_extension_word_count);
+      
+#ifdef PR_DIAGNOSTICS
+      printf("PR EHT first entry at 0x%x\n", (int)ehtp);
+#endif
+    }
+    
+    /* scan ... */
+
+    while (1) {
+      
+      /* Extract 32 bit length and offset */
+      uint32_t length;
+      uint32_t offset;
+      if (idx == 2) {
+        /* 32 bit offsets */
+        length = ((EHT32 *)ehtp)->length;
+        if (length == 0) break; /* end of table */
+        offset = ((EHT32 *)ehtp)->offset;
+        ehtp += sizeof(EHT32);
+      } else {
+        /* 16 bit offsets */
+        length = ((EHT16 *)ehtp)->length;
+        if (length == 0) break; /* end of table */
+        offset = ((EHT16 *)ehtp)->offset;
+        ehtp += sizeof(EHT16);
+      }
+      
+#ifdef PR_DIAGNOSTICS
+      printf("PR Got entry at 0x%x code=%d, length=0x%x, offset=0x%x\n",
+             (int)(ehtp-4), ((offset & 1) << 1) | (length & 1),
+             length & ~1, offset & ~1);
+#endif
+
+      /* Dispatch on the kind of entry */
+      switch (((offset & 1) << 1) | (length & 1)) {
+      case 0: /* cleanup */
+        if (state == _US_VIRTUAL_UNWIND_FRAME) {
+          /* Not a propagation barrier - skip */
+        } else {
+          /* Phase 2: call the cleanup if the return address is in range */
+          uint32_t padaddress;
+          uint32_t rangestartaddr = ucbp->pr_cache.fnstart + offset;
+          uint32_t rtn_addr = core_get(context, R_PC);
+          if (rangestartaddr <= rtn_addr && rtn_addr < rangestartaddr + length) {
+            /* It is in range. */
+	    /* We need both of these to support v1 and v2 */
+            landingpad_t *landingpadp = &((EHT_cleanup_tail *)ehtp)->landingpad;
+            landingpad_t landingpad = *landingpadp;
+            ehtp += sizeof(EHT_cleanup_tail);
+            /* Dump state into the ECO so we resume correctly after the cleanup. */
+            /* We simply save the address of the next EHT entry. */
+            ucbp->cleanup_cache.bitpattern[CLEANUP_EHTP] = (uint32_t)ehtp;
+            if (!__cxa_begin_cleanup(ucbp)) {
+              /* Should be impossible, using ARM's library */
+              DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_UNSPECIFIED);
+              return _URC_FAILURE;
+            }
+            /* Set up the VRS to enter the landing pad. */
+            padaddress = ehabiv2 ?
+	      __ARM_resolve_prel31(landingpadp) :
+	      ER_RO_OFFSET_TO_ADDR(landingpad,ucbp);
+            core_set(context, R_PC, padaddress);
+#ifdef PR_DIAGNOSTICS
+            printf("PR Got cleanup in range, cleanup addr=0x%x\n", core_get(context, R_PC));
+            printf("PR Saving EHT pointer 0x%x\n", (int)ehtp);
+#endif
+            DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_PADENTRY, padaddress);
+            /* Exit requesting upload the VRS to the real machine. */
+           return _URC_INSTALL_CONTEXT;
+          }
+        }
+        /* Phase 1, or phase 2 and not in range */
+        ehtp += sizeof(EHT_cleanup_tail);
+        break;
+      case 1: /* catch */
+        {
+          if (state == _US_VIRTUAL_UNWIND_FRAME) {
+            /* In range, and with a matching type? */
+            uint32_t rangestartaddr = ucbp->pr_cache.fnstart + offset;
+            uint32_t rtn_addr = core_get(context, R_PC);
+            void *matched_object;
+            length -= 1;   /* length had low bit set - clear it */
+            if (rangestartaddr <= rtn_addr && rtn_addr < rangestartaddr + length) {
+              /* In range */
+              __cxa_type_match_result matched_result;
+              uint32_t *rtti_ref = &((EHT_catch_tail *)ehtp)->rtti_ref;
+              uint32_t rtti_val = *rtti_ref;
+              if (rtti_val == CATCH_ALL_AND_TERMINATE) {
+                /* Always matches and causes propagation failure in phase 1 */
+#ifdef PR_DIAGNOSTICS
+                printf("PR Got CATCH_ALL_AND_TERMINATE in phase 1\n");
+#endif
+                DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_NOUNWIND);
+                return _URC_FAILURE;    
+              } else if (rtti_val == CATCH_ALL) {
+                matched_object = ucbp + 1;
+                matched_result = ctm_succeeded;
+              } else {
+                bool is_reference_type = ((uint32_t)(((EHT_catch_tail *)ehtp)->landingpad) & CATCH_REFERENCE)
+                                                           == CATCH_REFERENCE;
+                rtti_val = ehabiv2 ?
+		  (uint32_t)__ARM_resolve_target2((void *)rtti_ref) :
+		  (uint32_t)ER_RO_OFFSET_TO_ADDR(rtti_val, ucbp);
+                matched_result =__cxa_type_match(ucbp,
+                                                 (type_info *)rtti_val,
+                                                 is_reference_type,
+                                                 &matched_object);
+              }
+              if (matched_result != ctm_failed) {
+                /* In range and matches.
+                 * Record the propagation barrier details for ease of detection in phase 2.
+                 * We save a pointer to the middle of the handler entry -
+                 * this is fine, so long as we are consistent about it.
+                 */
+#ifdef PR_DIAGNOSTICS
+                printf("PR Got barrier in phase 1, result %d\n", (int)matched_result);
+                printf("PR Matched object address 0x%8.8x\n", matched_object); 
+#endif
+                if (matched_result == ctm_succeeded_with_ptr_to_base) {
+                  SAVE_CATCH_OF_BASEPTR_PROPAGATION_BARRIER(ucbp, core_get(context, R_SP),
+                                                            ehtp, matched_object);
+
+                } else {
+                  SAVE_CATCH_PROPAGATION_BARRIER(ucbp, core_get(context, R_SP),
+                                                 ehtp, matched_object);
+                }
+                DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_BARRIERFOUND,
+                                    (ehabiv2 ?
+				      __ARM_resolve_prel31(&((EHT_catch_tail *)ehtp)->landingpad) :
+				      ER_RO_OFFSET_TO_ADDR(((EHT_catch_tail *)ehtp)->landingpad, ucbp)));
+                DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_CPP_TYPEINFO, rtti_val);
+                return _URC_HANDLER_FOUND;
+              }
+            }
+            /* Not in range or no type match - fall thru to carry on scanning the table */
+          } else {
+            /* Else this is phase 2: have we encountered the saved barrier? */
+            if (CHECK_FOR_PROPAGATION_BARRIER(ucbp, core_get(context, R_SP), ehtp)) {
+              /* Yes we have.
+               * Set up the VRS to enter the landing pad,
+               * and upload the VRS to the real machine.
+               */
+              landingpad_t *landingpadp = &((EHT_catch_tail *)ehtp)->landingpad;
+              landingpad_t landingpad = *landingpadp;
+              uint32_t padaddress = ehabiv2 ?
+		__ARM_resolve_prel31(landingpadp) :
+		ER_RO_OFFSET_TO_ADDR(landingpad, ucbp);
+#ifdef PR_DIAGNOSTICS
+              printf("PR Got catch barrier in phase 2\n");
+#endif
+              core_set(context, R_PC, padaddress);
+              core_set(context, 0, (uint32_t)ucbp);
+              DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_PADENTRY, padaddress);
+              /* Exit requesting upload the VRS to the real machine. */
+              return _URC_INSTALL_CONTEXT;
+            }
+          }
+          /* Else carry on scanning the table */
+          ehtp += sizeof(EHT_catch_tail);
+          break;
+        }
+      case 2: /* function exception specification (fnspec) */
+        {
+          uint32_t counter_word = ((EHT_fnspec_tail *)ehtp)->rtti_count;
+          uint32_t rtti_count = counter_word & 0x7fffffff;   /* Extract offset count */
+          if (state == _US_VIRTUAL_UNWIND_FRAME) {
+            /* Phase 1 */
+            /* In range? Offset had low bit set - clear it */
+            uint32_t rangestartaddr = ucbp->pr_cache.fnstart + offset - 1;
+            uint32_t rtn_addr = core_get(context, R_PC);
+            if (rangestartaddr <= rtn_addr && rtn_addr < rangestartaddr + length) {
+              /* See if any type matches */
+              uint32_t *rttipp = &((EHT_fnspec_tail *)ehtp)->rtti_refs[0];
+              uint32_t i;
+              for (i = 0; i < rtti_count; i++) {
+                 void *matched_object;
+		 type_info * artti;
+		 if (ehabiv2)
+		   artti = (type_info *)__ARM_resolve_target2(rttipp);
+		 else
+		   artti = (type_info *)ER_RO_OFFSET_TO_ADDR(*rttipp, ucbp);
+                 if (__cxa_type_match(ucbp, artti, false, &matched_object)) {
+#ifdef PR_DIAGNOSTICS
+                   printf("PR Fnspec matched in phase 1\n");
+#endif
+                   break;
+                 }
+                 rttipp++;
+              }
+
+              if (i == rtti_count) { /* NB case rtti_count==0 forces no match [for throw()] */
+                /* No match - fnspec violation is a propagation barrier */
+#ifdef PR_DIAGNOSTICS
+                printf("PR Got fnspec barrier in phase 1\n");
+#endif
+                SAVE_FNSPEC_PROPAGATION_BARRIER(ucbp, core_get(context, R_SP), ehtp); /* save ptr to the count of types */
+                /* Even if this is a fnspec with a landing pad, we always end up in
+                 * __cxa_call_unexpected so tell the debugger thats where we're going
+                 */
+                DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_BARRIERFOUND, &__cxa_call_unexpected);
+                return _URC_HANDLER_FOUND;
+              }
+            } /* if (in range...) */
+
+            /* Fall out of the 'if' to continue table scanning */
+
+          } else {
+            /* Else this is phase 2: have we encountered the saved barrier? */
+            if (CHECK_FOR_PROPAGATION_BARRIER(ucbp, core_get(context, R_SP), ehtp)) {
+              /* Yes we have. Fill in the UCB barrier_cache for entry to __cxa_call_unexpected */
+              uint32_t *p = (uint32_t *)ehtp; /* ptr to rtti count */
+              ucbp->barrier_cache.bitpattern[BARRIER_FNSPECCOUNT] = rtti_count;
+              ucbp->barrier_cache.bitpattern[BARRIER_FNSPECBASE] = ehabiv2 ? 0 :ER_RO_OFFSET_TO_ADDR(0, ucbp);
+              ucbp->barrier_cache.bitpattern[BARRIER_FNSPECSTRIDE] = 4; /* stride */
+              ucbp->barrier_cache.bitpattern[BARRIER_FNSPECARRAY]  = (uint32_t)(p + 1); /* address of rtti offset list */
+
+              /* If this is a fnspec with an attached landing pad, we must enter
+               * the pad immediately. Otherwise we need to unwind the frame before
+               * calling __cxa_call_unexpected() so set a flag to make this happen.
+               */
+              if (counter_word == rtti_count)
+                phase2_call_unexpected_after_unwind = true; /* no pad, enter later */
+              else { /* pad */
+                landingpad_t *landingpadp;
+                landingpad_t landingpad;
+                uint32_t padaddress;
+#ifdef PR_DIAGNOSTICS
+                printf("PR Got fnspec barrier in phase 2 (immediate entry)\n");
+#endif
+                ehtp += (sizeof(((EHT_fnspec_tail *)ehtp)->rtti_count) +
+                         sizeof(uint32_t) * rtti_count);  /* point at pad offset */
+                landingpadp = (landingpad_t *)ehtp;
+                landingpad = *(landingpad_t *)ehtp;
+                padaddress = ehabiv2 ?
+		  __ARM_resolve_prel31(landingpadp) :
+		  ER_RO_OFFSET_TO_ADDR(landingpad, ucbp);
+                core_set(context, 0, (uint32_t)ucbp);
+                core_set(context, R_PC, padaddress);
+                /* Even if this is a fnspec with a landing pad, in phase 1 we said we'd
+                 * end up in __cxa_call_unexpected so show the same thing now
+                 */
+                DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_PADENTRY, &__cxa_call_unexpected);
+                return _URC_INSTALL_CONTEXT;
+              }
+            } /* endif (barrier match) */
+          } /* endif (which phase) */
+          
+          /* Advance to the next item, remembering to skip the landing pad if present */
+          ehtp += (sizeof(((EHT_fnspec_tail *)ehtp)->rtti_count) +
+                   sizeof(uint32_t) * rtti_count +
+                   (counter_word == rtti_count ? 0 : sizeof(landingpad_t)));
+          break;
+        }
+      case 3: /* unallocated */
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_TABLECORRUPT);
+        return _URC_FAILURE;
+      } /* switch */
+
+    } /* while (1) */
+    
+#ifdef PR_DIAGNOSTICS
+    printf("PR Reached end of EHT\n");
+#endif
+
+  } /* if out-of-line EHT */
+
+
+  /* Do a virtual unwind of this frame - load the first unwind bytes then loop.
+   * Loop exit is by executing opcode CODE_FINISH.
+   */
+
+  ud.unwind_word = *(uint32_t *)eht_startp;             /* first word */
+  ud.unwind_word_pointer = (uint32_t *)eht_startp + 1;  /* ptr to extension words, if any */
+  if (idx == 0) {                  /* short description */
+    ud.unwind_words_remaining = 0; /* no further words */
+    ud.unwind_word <<= 8;          /* 3 explicit unwind bytes in this word */
+    ud.unwind_word_bytes_remaining = 3;
+  } else {                         /* long description: extension word count in bits 16-23 */
+    ud.unwind_words_remaining = ((ud.unwind_word) >> 16) & 0xff;
+    ud.unwind_word <<= 16;         /* 2 explicit unwind bytes in this word */
+    ud.unwind_word_bytes_remaining = 2;
+  }
+
+#ifdef PR_DIAGNOSTICS
+  /*  debug_print_vrs(context); */
+#endif
+
+  while (1) {
+    uint8_t ub = next_unwind_byte(&ud);
+
+#ifdef PR_DIAGNOSTICS
+    printf("PR Unwind byte 0x%x\n", ub);
+#endif
+
+    /* decode and execute the current byte ... */
+
+    if (ub == CODE_FINISH) { /* finished unwinding */
+      if (!wrote_pc) {
+        uint32_t lr;
+        if (!wrote_lr) {
+          /* If neither pc nor lr was written, the saved return address was
+           * not restored. This indicates broken unwind instructions.
+           */
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_TABLECORRUPT);
+          return _URC_FAILURE;
+        }
+        _Unwind_VRS_Get(context, _UVRSC_CORE, R_LR, _UVRSD_UINT32, &lr);
+        core_set(context, R_PC, lr);
+        wrote_pc_from_lr = true;
+      }
+#ifdef PR_DIAGNOSTICS
+      {
+        uint32_t nextpc;
+        _Unwind_VRS_Get(context, _UVRSC_CORE, R_PC, _UVRSD_UINT32, &nextpc);
+        printf("PR Next PC is  0x%x\n", nextpc);
+      }
+#endif
+      break;
+    }
+    if (ub <= 0x3f) { /* 00nnnnnn: vsp += (nnnnnn << 2) + 4 */
+      uint32_t increment = ((ub & 0x3f) << 2) + 4;
+      core_set(context, R_SP, core_get(context, R_SP) + increment);
+      continue;
+    }
+    if (ub <= 0x7f) { /* 01xxxxxx: vsp -= (xxxxxx << 2) + 4 */
+      uint32_t decrement = ((ub & 0x3f) << 2) + 4;
+      core_set(context, R_SP, core_get(context, R_SP) - decrement);
+      continue;
+    }
+    if (ub <= 0x8f) { /* 100000000 00000000: refuse, 1000rrrr rrrrrrrr: pop integer regs */
+      uint32_t mask = (ub & 0xf) << 12;
+      ub = next_unwind_byte(&ud);
+      mask |= ub << 4;
+      if (mask == 0) { /* 10000000 00000000 refuse to unwind */
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_NOUNWIND);
+        return _URC_FAILURE;
+      }
+      if (_Unwind_VRS_Pop(context, _UVRSC_CORE, mask, _UVRSD_UINT32) != _UVRSR_OK) {
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+        return _URC_FAILURE;
+      }
+      if (mask & (1 << R_PC)) wrote_pc = true;
+      if (mask & (1 << R_LR)) wrote_lr = true;
+      continue;
+    }
+    if (ub <= 0x9f) { /* 1001nnnn: vsp = r[nnnn] if not 13,15 */
+      uint8_t regno = ub & 0xf;
+      if (regno == 13 || regno == R_PC) {  /* reserved */
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_CPP_BADOPCODE);
+        return _URC_FAILURE;
+      }
+      core_set(context, R_SP, core_get(context, regno));
+      continue;
+    }
+    if (ub <= 0xaf) { /* 1010xnnn: pop r4-r[4+nnn], +r14 if x */
+      uint32_t mask = count_to_mask((ub & 0x7) + 1) << 4;
+      if (ub & 0x8) {
+        mask |= (1 << R_LR);
+        wrote_lr = true;
+      }
+      if (_Unwind_VRS_Pop(context, _UVRSC_CORE, mask, _UVRSD_UINT32) != _UVRSR_OK) {
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+        return _URC_FAILURE;
+      }
+      continue;
+    }
+    if (ub <= 0xb7) {
+      /* if (ub == 0xb0) is CODE_FINISH, handled earlier */
+      if (ub == 0xb1) { /* 10110001 0000iiii pop integer regs, others reserved */
+        uint32_t mask = next_unwind_byte(&ud);
+        if (mask == 0 || mask > 0xf) { /* reserved */
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_CPP_BADOPCODE);
+          return _URC_FAILURE;
+        }
+        if (_Unwind_VRS_Pop(context, _UVRSC_CORE, mask, _UVRSD_UINT32) != _UVRSR_OK) {
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+          return _URC_FAILURE;
+        }
+        continue;
+      }
+      if (ub == 0xb2) { /* 10110010 uleb128 : vsp += (uleb128 << 2) + 0x204 */
+        uint32_t u = 0;
+        uint32_t n = 0;
+        /* decode */
+        while (1) {
+          ub = next_unwind_byte(&ud);
+          u |= (ub & 0x7f) << n;
+          if ((ub & 0x80) == 0) break;
+          n += 7;
+        }
+        core_set(context, R_SP, core_get(context, R_SP) + (u << 2) + 0x204);
+        continue;
+      }
+      if (ub == 0xb3) { /* 10110011: pop vfp from FSTMFDX */
+        uint32_t discriminator = next_unwind_byte(&ud);
+        discriminator = ((discriminator & 0xf0) << 12) | ((discriminator & 0x0f) + 1);
+        if (_Unwind_VRS_Pop(context, _UVRSC_VFP, discriminator, _UVRSD_VFPX) != _UVRSR_OK) {
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+          return _URC_FAILURE;
+        }
+        continue;
+      }
+      { /* 101101nn: was pop fpa, now spare */
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_CPP_BADOPCODE);
+        return _URC_FAILURE;
+      }
+    } /* if (ub <= 0xb7) ... */
+    if (ub <= 0xbf) { /* 10111nnn: pop vfp from FSTMFDX */
+      uint32_t discriminator = 0x80000 | ((ub & 0x7) + 1);
+      if (_Unwind_VRS_Pop(context, _UVRSC_VFP, discriminator, _UVRSD_VFPX) != _UVRSR_OK) {
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+        return _URC_FAILURE;
+      }
+      continue;
+    }
+    if (ub <= 0xc7) {
+      if (ub == 0xc7) { /* 11000111: WMMX C regs */
+        uint32_t mask = next_unwind_byte(&ud);
+        if (mask == 0 || mask > 0xf) { /* reserved */
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_CPP_BADOPCODE);
+          return _URC_FAILURE;
+        }
+        if (_Unwind_VRS_Pop(context, _UVRSC_WMMXC, mask, _UVRSD_UINT32) != _UVRSR_OK) {
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+          return _URC_FAILURE;
+        }
+        continue;
+      } else if (ub == 0xc6) { /* 11000110: WMMX D regs */
+        uint32_t discriminator = next_unwind_byte(&ud);
+        discriminator = ((discriminator & 0xf0) << 12) | ((discriminator & 0x0f) + 1);
+        if (_Unwind_VRS_Pop(context, _UVRSC_WMMXD, discriminator, _UVRSD_UINT64) != _UVRSR_OK) {
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+          return _URC_FAILURE;
+        }
+        continue;
+      } else {
+        /* 11000nnn (nnn != 6, 7): WMMX D regs */
+        uint32_t discriminator = 0xa0000 | ((ub & 0x7) + 1);
+        if (_Unwind_VRS_Pop(context, _UVRSC_WMMXD, discriminator, _UVRSD_UINT64) != _UVRSR_OK) {
+          DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+          return _URC_FAILURE;
+        }
+        continue;
+      }
+    } /* if (ub <= 0xc7) ... */
+    if (ub == 0xc8 || /* 11001000 sssscccc: pop VFP hi regs from FSTMFDD */
+        ub == 0xc9) { /* 11001001 sssscccc: pop VFP from FSTMFDD */
+      uint32_t discriminator = next_unwind_byte(&ud);
+      discriminator = ((discriminator & 0xf0) << 12) | ((discriminator & 0x0f) + 1);
+      if (ub == 0xc8) discriminator += 16 << 16;
+      if (_Unwind_VRS_Pop(context, _UVRSC_VFP, discriminator, _UVRSD_DOUBLE) != _UVRSR_OK) {
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+        return _URC_FAILURE;
+      }
+      continue;
+    }
+    if (ub <= 0xcf) { /* spare */
+      DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_CPP_BADOPCODE);
+      return _URC_FAILURE;
+    }
+    if (ub <= 0xd7) { /* 11010nnn: pop VFP from FSTMFDD */
+      uint32_t discriminator = 0x80000 | ((ub & 0x7) + 1);
+      if (_Unwind_VRS_Pop(context, _UVRSC_VFP, discriminator, _UVRSD_DOUBLE) != _UVRSR_OK) {
+        DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_VRSFAILED);
+        return _URC_FAILURE;
+      }
+      continue;
+    }
+    /* and in fact everything else is currently reserved or spare */
+    DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_ENDING, _UAARG_ENDING_CPP_BADOPCODE);
+    return _URC_FAILURE;
+  }
+ 
+#ifdef PR_DIAGNOSTICS
+  /* debug_print_vrs(context); */
+#endif
+
+  /* The VRS has now been updated to reflect the virtual unwind.
+   * If we are dealing with an unmatched fnspec, pop intervening frames 
+   * and call unexpected(). Else return to our caller with an
+   * indication to continue unwinding.
+   */
+
+  if (phase2_call_unexpected_after_unwind) {
+    /* Set up the VRS to enter __cxa_call_unexpected,
+     * and upload the VRS to the real machine.
+     * The barrier_cache was initialised earlier.
+     */
+#ifdef PR_DIAGNOSTICS
+    printf("PR Got fnspec barrier in phase 2 (unwinding completed)\n");
+#endif
+    core_set(context, 0, (uint32_t)ucbp);
+    if (!wrote_pc_from_lr) {
+      uint32_t pc;
+      /* Move the return address to lr to simulate a call */
+      _Unwind_VRS_Get(context, _UVRSC_CORE, R_PC, _UVRSD_UINT32, &pc);
+      core_set(context, R_LR, pc);
+    }
+    core_set(context, R_PC, (uint32_t)&__cxa_call_unexpected);
+    DEBUGGER_BOTTLENECK(ucbp, _UASUBSYS_CPP, _UAACT_PADENTRY, &__cxa_call_unexpected);
+    return _URC_INSTALL_CONTEXT;
+  }
+  
+  /* Else continue with next frame */
+  return _URC_CONTINUE_UNWIND;
+}
+
+#endif
+/* end ifdef prcommon_c */