1 files changed, 93 insertions, 28 deletions

diff --git a/gcc/config/arm/unwind-arm.c b/gcc/config/arm/unwind-arm.c
index 4d703dbf09a..b3f8a00dcb5 100644
--- a/gcc/config/arm/unwind-arm.c
+++ b/gcc/config/arm/unwind-arm.c
@@ -27,6 +27,10 @@
    Boston, MA 02110-1301, USA.  */
 #include "unwind.h"
 
+/* We add a prototype for abort here to avoid creating a dependency on
+   target headers.  */
+extern void abort (void);
+
 /* Definitions for C++ runtime support routines.  We make these weak
    declarations to avoid pulling in libsupc++ unnecessarily.  */
 typedef unsigned char bool;
@@ -54,7 +58,7 @@ __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);
 #define UCB_FORCED_STOP_FN(ucbp) ((ucbp)->unwinder_cache.reserved1)
 #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)
 #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)
-#define UCB_FORCED_STOP_ARG(ucb) ((ucbp)->unwinder_cache.reserved4)
+#define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)
 
 struct core_regs
 {
@@ -107,6 +111,7 @@ typedef struct
   /* The first fields must be the same as a phase2_vrs.  */
   _uw demand_save_flags;
   struct core_regs core;
+  _uw prev_sp; /* Only valid during forced unwinding.  */
   struct vfp_regs vfp;
   struct fpa_regs fpa;
 } phase1_vrs;
@@ -497,11 +502,21 @@ unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs)
 /* Perform phase2 forced unwinding.  */
 
 static _Unwind_Reason_Code
-unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs)
+unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,
+		      int resuming)
 {
   _Unwind_Stop_Fn stop_fn = (_Unwind_Stop_Fn) UCB_FORCED_STOP_FN (ucbp);
   void *stop_arg = (void *)UCB_FORCED_STOP_ARG (ucbp);
-  _Unwind_Reason_Code pr_result;
+  _Unwind_Reason_Code pr_result = 0;
+  /* We use phase1_vrs here even though we do not demand save, for the
+     prev_sp field.  */
+  phase1_vrs saved_vrs, next_vrs;
+
+  /* Save the core registers.  */
+  saved_vrs.core = entry_vrs->core;
+  /* We don't need to demand-save the non-core registers, because we
+     unwind in a single pass.  */
+  saved_vrs.demand_save_flags = 0;
 
   /* Unwind until we reach a propagation barrier.  */
   do
@@ -511,27 +526,51 @@ unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs)
       _Unwind_Reason_Code stop_code;
 
       /* Find the entry for this routine.  */
-      entry_code = get_eit_entry (ucbp, entry_vrs->core.r[R_PC]);
+      entry_code = get_eit_entry (ucbp, saved_vrs.core.r[R_PC]);
 
-      action = _US_UNWIND_FRAME_STARTING | _US_FORCE_UNWIND;
-      if (entry_code == _URC_END_OF_STACK)
-	action |= _US_END_OF_STACK;
-      else if (entry_code != _URC_OK)
-	return _URC_FAILURE;
+      if (resuming)
+	{
+	  action = _US_UNWIND_FRAME_RESUME | _US_FORCE_UNWIND;
+	  resuming = 0;
+	}
+      else
+	action = _US_UNWIND_FRAME_STARTING | _US_FORCE_UNWIND;
+
+      if (entry_code == _URC_OK)
+	{
+	  UCB_SAVED_CALLSITE_ADDR (ucbp) = saved_vrs.core.r[R_PC];
+
+	  next_vrs = saved_vrs;
+
+	  /* Call the pr to decide what to do.  */
+	  pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
+	    (action, ucbp, (void *) &next_vrs);
+
+	  saved_vrs.prev_sp = next_vrs.core.r[R_SP];
+	}
+      else
+	{
+	  /* Treat any failure as the end of unwinding, to cope more
+	     gracefully with missing EH information.  Mixed EH and
+	     non-EH within one object will usually result in failure,
+	     because the .ARM.exidx tables do not indicate the end
+	     of the code to which they apply; but mixed EH and non-EH
+	     shared objects should return an unwind failure at the
+	     entry of a non-EH shared object.  */
+	  action |= _US_END_OF_STACK;
+
+	  saved_vrs.prev_sp = saved_vrs.core.r[R_SP];
+	}
 
       stop_code = stop_fn (1, action, ucbp->exception_class, ucbp,
-			   (void *)entry_vrs, stop_arg);
+			   (void *)&saved_vrs, stop_arg);
       if (stop_code != _URC_NO_REASON)
 	return _URC_FAILURE;
 
-      if (entry_code == _URC_END_OF_STACK)
+      if (entry_code != _URC_OK)
 	return entry_code;
 
-      UCB_SAVED_CALLSITE_ADDR (ucbp) = entry_vrs->core.r[R_PC];
-
-      /* Call the pr to decide what to do.  */
-      pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
-	(action, ucbp, (void *) entry_vrs);
+      saved_vrs = next_vrs;
     }
   while (pr_result == _URC_CONTINUE_UNWIND);
 
@@ -542,7 +581,20 @@ unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs)
       return _URC_FAILURE;
     }
 
-  restore_core_regs (&entry_vrs->core);
+  restore_core_regs (&saved_vrs.core);
+}
+
+/* This is a very limited implementation of _Unwind_GetCFA.  It returns
+   the stack pointer as it is about to be unwound, and is only valid
+   while calling the stop function during forced unwinding.  If the
+   current personality routine result is going to run a cleanup, this
+   will not be the CFA; but when the frame is really unwound, it will
+   be.  */
+
+_Unwind_Word
+_Unwind_GetCFA (_Unwind_Context *context)
+{
+  return ((phase1_vrs *) context)->prev_sp;
 }
 
 /* Perform phase1 unwinding.  UCBP is the exception being thrown, and
@@ -610,7 +662,7 @@ __gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *ucbp,
   /* Set the pc to the call site.  */
   entry_vrs->core.r[R_PC] = entry_vrs->core.r[R_LR];
 
-  return unwind_phase2_forced (ucbp, entry_vrs);
+  return unwind_phase2_forced (ucbp, entry_vrs, 0);
 }
 
 _Unwind_Reason_Code
@@ -620,18 +672,21 @@ _Unwind_Reason_Code
 __gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs)
 {
   _Unwind_Reason_Code pr_result;
-  _Unwind_State action;
 
   /* Recover the saved address.  */
   entry_vrs->core.r[R_PC] = UCB_SAVED_CALLSITE_ADDR (ucbp);
 
-  /* Call the cached PR.  */
-  action = _US_UNWIND_FRAME_RESUME;
   if (UCB_FORCED_STOP_FN (ucbp))
-    action |= _US_FORCE_UNWIND;
+    {
+      unwind_phase2_forced (ucbp, entry_vrs, 1);
 
+      /* We can't return failure at this point.  */
+      abort ();
+    }
+
+  /* Call the cached PR.  */
   pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
-	(action, ucbp, (_Unwind_Context *) entry_vrs);
+	(_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);
 
   switch (pr_result)
     {
@@ -641,10 +696,7 @@ __gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs)
 
     case _URC_CONTINUE_UNWIND:
       /* Continue unwinding the next frame.  */
-      if (UCB_FORCED_STOP_FN (ucbp))
-	return unwind_phase2_forced (ucbp, entry_vrs);
-      else
-	unwind_phase2 (ucbp, entry_vrs);
+      unwind_phase2 (ucbp, entry_vrs);
 
     default:
       abort ();
@@ -664,7 +716,7 @@ __gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block * ucbp,
   /* Set the pc to the call site.  */
   entry_vrs->core.r[R_PC] = entry_vrs->core.r[R_LR];
   /* Continue unwinding the next frame.  */
-  return unwind_phase2_forced (ucbp, entry_vrs);
+  return unwind_phase2_forced (ucbp, entry_vrs, 0);
 }
 
 /* Clean up an exception object when unwinding is complete.  */
@@ -947,3 +999,16 @@ __aeabi_unwind_cpp_pr2 (_Unwind_State state,
 {
   return __gnu_unwind_pr_common (state, ucbp, context, 2);
 }
+
+/* These two should never be used.  */
+_Unwind_Ptr
+_Unwind_GetDataRelBase (_Unwind_Context *context __attribute__ ((unused)))
+{
+  abort ();
+}
+
+_Unwind_Ptr
+_Unwind_GetTextRelBase (_Unwind_Context *context __attribute__ ((unused)))
+{
+  abort ();
+}