PR c++/46245

[pf3gnuchains/gcc-fork.git] / gcc / unwind-dw2.c

diff --git a/gcc/unwind-dw2.c b/gcc/unwind-dw2.c
index 82958b0..25990b4 100644 (file)
--- a/gcc/unwind-dw2.c
+++ b/gcc/unwind-dw2.c
@@ -1,6 +1,6 @@
 /* DWARF2 exception handling and frame unwind runtime interface routines.
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-   2008, 2009  Free Software Foundation, Inc.
+   2008, 2009, 2010, 2011  Free Software Foundation, Inc.
 
    This file is part of GCC.
 
@@ -37,6 +37,10 @@
 #include "gthr.h"
 #include "unwind-dw2.h"
 
+#ifdef HAVE_SYS_SDT_H
+#include <sys/sdt.h>
+#endif
+
 #ifndef __USING_SJLJ_EXCEPTIONS__
 
 #ifndef STACK_GROWS_DOWNWARD
@@ -356,7 +360,16 @@ extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context,
       aug += 2;
     }
 
-  /* Immediately following the augmentation are the code and
+  /* After the augmentation resp. pointer for "eh" augmentation
+     follows for CIE version >= 4 address size byte and
+     segment size byte.  */
+  if (__builtin_expect (cie->version >= 4, 0))
+    {
+      if (p[0] != sizeof (void *) || p[1] != 0)
+       return NULL;
+      p += 2;
+    }
+  /* Immediately following this are the code and
      data alignment and return address column.  */
   p = read_uleb128 (p, &utmp);
   fs->code_align = (_Unwind_Word)utmp;
@@ -404,7 +417,7 @@ extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context,
       else if (aug[0] == 'P')
        {
          _Unwind_Ptr personality;
-         
+
          p = read_encoded_value (context, *p, p + 1, &personality);
          fs->personality = (_Unwind_Personality_Fn) personality;
          aug += 1;
@@ -672,7 +685,7 @@ execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end,
          /* Unary operations.  */
          gcc_assert (stack_elt);
          stack_elt -= 1;
-         
+
          result = stack[stack_elt];
 
          switch (op)
@@ -749,7 +762,7 @@ execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end,
            _Unwind_Word first, second;
            gcc_assert (stack_elt >= 2);
            stack_elt -= 2;
-           
+
            second = stack[stack_elt];
            first = stack[stack_elt + 1];
 
@@ -765,7 +778,7 @@ execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end,
                result = second - first;
                break;
              case DW_OP_mod:
-               result = (_Unwind_Sword) second % (_Unwind_Sword) first;
+               result = second % first;
                break;
              case DW_OP_mul:
                result = second * first;
@@ -822,7 +835,7 @@ execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end,
        case DW_OP_bra:
          gcc_assert (stack_elt);
          stack_elt -= 1;
-         
+
          offset = read_2s (op_ptr);
          op_ptr += 2;
          if (stack[stack_elt] != 0)
@@ -902,7 +915,7 @@ execute_cfa_program (const unsigned char *insn_ptr,
        case DW_CFA_set_loc:
          {
            _Unwind_Ptr pc;
-           
+
            insn_ptr = read_encoded_value (context, fs->fde_encoding,
                                           insn_ptr, &pc);
            fs->pc = (void *) pc;
@@ -1164,7 +1177,7 @@ uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs)
   if (fs->lsda_encoding != DW_EH_PE_omit)
     {
       _Unwind_Ptr lsda;
-      
+
       aug = read_encoded_value (context, fs->lsda_encoding, aug, &lsda);
       context->lsda = (void *) lsda;
     }
@@ -1248,7 +1261,7 @@ _Unwind_SetSpColumn (struct _Unwind_Context *context, void *cfa,
                     _Unwind_SpTmp *tmp_sp)
 {
   int size = dwarf_reg_size_table[__builtin_dwarf_sp_column ()];
-  
+
   if (size == sizeof(_Unwind_Ptr))
     tmp_sp->ptr = (_Unwind_Ptr) cfa;
   else
@@ -1473,7 +1486,8 @@ uw_init_context_1 (struct _Unwind_Context *context,
   context->ra = __builtin_extract_return_addr (outer_ra);
 }
 
-static void _Unwind_DebugHook (void *, void *) __attribute__ ((__noinline__));
+static void _Unwind_DebugHook (void *, void *)
+  __attribute__ ((__noinline__, __used__, __noclone__));
 
 /* This function is called during unwinding.  It is intended as a hook
    for a debugger to intercept exceptions.  CFA is the CFA of the
@@ -1483,7 +1497,13 @@ static void
 _Unwind_DebugHook (void *cfa __attribute__ ((__unused__)),
                   void *handler __attribute__ ((__unused__)))
 {
+  /* We only want to use stap probes starting with v3.  Earlier
+     versions added too much startup cost.  */
+#if defined (HAVE_SYS_SDT_H) && defined (STAP_PROBE2) && _SDT_NOTE_TYPE >= 3
+  STAP_PROBE2 (libgcc, unwind, cfa, handler);
+#else
   asm ("");
+#endif
 }
 
 /* Install TARGET into CURRENT so that we can return to it.  This is a
@@ -1559,7 +1579,13 @@ uw_install_context_1 (struct _Unwind_Context *current,
 static inline _Unwind_Ptr
 uw_identify_context (struct _Unwind_Context *context)
 {
-  return _Unwind_GetCFA (context);
+  /* The CFA is not sufficient to disambiguate the context of a function
+     interrupted by a signal before establishing its frame and the context
+     of the signal itself.  */
+  if (STACK_GROWS_DOWNWARD)
+    return _Unwind_GetCFA (context) - _Unwind_IsSignalFrame (context);
+  else
+    return _Unwind_GetCFA (context) + _Unwind_IsSignalFrame (context);
 }