예제 #1
0
static void
read_variable (MonoDebugVarInfo *var, guint8 *ptr, guint8 **rptr)
{
	var->index = read_leb128 (ptr, &ptr);
	var->offset = read_sleb128 (ptr, &ptr);
	var->size = read_leb128 (ptr, &ptr);
	var->begin_scope = read_leb128 (ptr, &ptr);
	var->end_scope = read_leb128 (ptr, &ptr);
	READ_UNALIGNED (MonoType *, ptr, var->type);
	ptr += sizeof (gpointer);
	*rptr = ptr;
}
예제 #2
0
static int
get_cie_encoding (const struct dwarf_cie *cie)
{
  const unsigned char *aug, *p;
  _Unwind_Ptr dummy;
  _uleb128_t utmp;
  _sleb128_t stmp;

  aug = cie->augmentation;
  p = aug + strlen ((const char *)aug) + 1; /* Skip the augmentation string.  */
  if (__builtin_expect (cie->version >= 4, 0))
    {
      if (p[0] != sizeof (void *) || p[1] != 0)
	return DW_EH_PE_omit;		/* We are not prepared to handle unexpected
					   address sizes or segment selectors.  */
      p += 2;				/* Skip address size and segment size.  */
    }

  if (aug[0] != 'z')
    return DW_EH_PE_absptr;

  p = read_uleb128 (p, &utmp);		/* Skip code alignment.  */
  p = read_sleb128 (p, &stmp);		/* Skip data alignment.  */
  if (cie->version == 1)		/* Skip return address column.  */
    p++;
  else
    p = read_uleb128 (p, &utmp);

  aug++;				/* Skip 'z' */
  p = read_uleb128 (p, &utmp);		/* Skip augmentation length.  */
  while (1)
    {
      /* This is what we're looking for.  */
      if (*aug == 'R')
	return *p;
      /* Personality encoding and pointer.  */
      else if (*aug == 'P')
	{
	  /* ??? Avoid dereferencing indirect pointers, since we're
	     faking the base address.  Gotta keep DW_EH_PE_aligned
	     intact, however.  */
	  p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy);
	}
      /* LSDA encoding.  */
      else if (*aug == 'L')
	p++;
      /* Otherwise end of string, or unknown augmentation.  */
      else
	return DW_EH_PE_absptr;
      aug++;
    }
}
static void
dwarf2_tracepoint_var_ref (struct symbol * symbol, struct agent_expr * ax,
			   struct axs_value * value, unsigned char *data,
			   int size)
{
  if (size == 0)
    error ("Symbol \"%s\" has been optimized out.",
	   SYMBOL_PRINT_NAME (symbol));

  if (size == 1
      && data[0] >= DW_OP_reg0
      && data[0] <= DW_OP_reg31)
    {
      value->kind = axs_lvalue_register;
      value->u.reg = data[0] - DW_OP_reg0;
    }
  else if (data[0] == DW_OP_regx)
    {
      ULONGEST reg;
      read_uleb128 (data + 1, data + size, &reg);
      value->kind = axs_lvalue_register;
      value->u.reg = reg;
    }
  else if (data[0] == DW_OP_fbreg)
    {
      /* And this is worse than just minimal; we should honor the frame base
	 as above.  */
      int frame_reg;
      LONGEST frame_offset;
      unsigned char *buf_end;

      buf_end = read_sleb128 (data + 1, data + size, &frame_offset);
      if (buf_end != data + size)
	error ("Unexpected opcode after DW_OP_fbreg for symbol \"%s\".",
	       SYMBOL_PRINT_NAME (symbol));

      TARGET_VIRTUAL_FRAME_POINTER (ax->scope, &frame_reg, &frame_offset);
      ax_reg (ax, frame_reg);
      ax_const_l (ax, frame_offset);
      ax_simple (ax, aop_add);

      ax_const_l (ax, frame_offset);
      ax_simple (ax, aop_add);
      value->kind = axs_lvalue_memory;
    }
  else
    error ("Unsupported DWARF opcode in the location of \"%s\".",
	   SYMBOL_PRINT_NAME (symbol));
}
예제 #4
0
static int
get_cie_encoding (struct dwarf_cie *cie)
{
  const unsigned char *aug, *p;
  _Unwind_Ptr dummy;
  _Unwind_Word utmp;
  _Unwind_Sword stmp;

  aug = cie->augmentation;
  if (aug[0] != 'z')
    return DW_EH_PE_absptr;

  /* Skip the augmentation string.  */
  p = aug + strlen ((const char *) aug) + 1;
  p = read_uleb128 (p, &utmp);		/* Skip code alignment.  */
  p = read_sleb128 (p, &stmp);		/* Skip data alignment.  */
  p++;					/* Skip return address column.  */

  aug++;				/* Skip 'z' */
  p = read_uleb128 (p, &utmp);		/* Skip augmentation length.  */
  while (1)
    {
      /* This is what we're looking for.  */
      if (*aug == 'R')
	return *p;
      /* Personality encoding and pointer.  */
      else if (*aug == 'P')
	{
	  /* ??? Avoid dereferencing indirect pointers, since we're
	     faking the base address.  Gotta keep DW_EH_PE_aligned
	     intact, however.  */
	  p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy);
	}
      /* LSDA encoding.  */
      else if (*aug == 'L')
	p++;
      /* Otherwise end of string, or unknown augmentation.  */
      else
	return DW_EH_PE_absptr;
      aug++;
    }
}
예제 #5
0
파일: lsda.c 프로젝트: dleonard0/ponyc
static uintptr_t read_encoded_ptr(const uint8_t** data, uint8_t encoding)
{
  const uint8_t* p = *data;

  if(encoding == DW_EH_PE_omit)
    return 0;

  // Base pointer.
  uintptr_t result;

  switch(encoding & 0x0F)
  {
    case DW_EH_PE_absptr:
      result = *((uintptr_t*)p);
      p += sizeof(uintptr_t);
      break;

    case DW_EH_PE_udata2:
      result = *((uint16_t*)p);
      p += sizeof(uint16_t);
      break;

    case DW_EH_PE_udata4:
      result = *((uint32_t*)p);
      p += sizeof(uint32_t);
      break;

#if __UINTPTR_MAX__ >= __UINT64_MAX__
    case DW_EH_PE_udata8:
      result = *((uint64_t*)p);
      p += sizeof(uint64_t);
      break;
#endif

    case DW_EH_PE_sdata2:
      result = *((int16_t*)p);
      p += sizeof(int16_t);
      break;

    case DW_EH_PE_sdata4:
      result = *((int32_t*)p);
      p += sizeof(int32_t);
      break;

#if __UINTPTR_MAX__ >= __UINT64_MAX__
    case DW_EH_PE_sdata8:
      result = *((int64_t*)p);
      p += sizeof(int64_t);
      break;
#endif

    case DW_EH_PE_sleb128:
      result = read_sleb128(&p);
      break;

    case DW_EH_PE_uleb128:
      result = read_uleb128(&p);
      break;

    default:
      abort();
      break;
  }

  *data = p;
  return result;
}
예제 #6
0
bool
db_dwarf_line_at_pc(const char *linetab, size_t linetabsize, uintptr_t pc,
    const char **outdirname, const char **outbasename, int *outline)
{
	struct dwbuf table = { .buf = linetab, .len = linetabsize };

	/*
	 * For simplicity, we simply brute force search through the entire
	 * line table each time.
	 */
	uint32_t unitsize;
	struct dwbuf unit;
next:
	/* Line tables are a sequence of compilation unit entries. */
	if (!read_u32(&table, &unitsize) || unitsize >= 0xfffffff0 ||
	    !read_buf(&table, &unit, unitsize))
		return (false);

	uint16_t version;
	uint32_t header_size;
	if (!read_u16(&unit, &version) || version > 2 ||
	    !read_u32(&unit, &header_size))
		goto next;

	struct dwbuf headerstart = unit;
	uint8_t min_insn_length, default_is_stmt, line_range, opcode_base;
	int8_t line_base;
	if (!read_u8(&unit, &min_insn_length) ||
	    !read_u8(&unit, &default_is_stmt) ||
	    !read_s8(&unit, &line_base) ||
	    !read_u8(&unit, &line_range) ||
	    !read_u8(&unit, &opcode_base))
		goto next;

	/*
	 * Directory and file names are next in the header, but for now we
	 * skip directly to the line number program.
	 */
	struct dwbuf names = unit;
	unit = headerstart;
	if (!skip_bytes(&unit, header_size))
		return (false);

	/* VM registers. */
	uint64_t address = 0, file = 1, line = 1, column = 0;
	uint8_t is_stmt = default_is_stmt;
	bool basic_block = false, end_sequence = false;
	bool prologue_end = false, epilogue_begin = false;

	/* Last line table entry emitted, if any. */
	bool have_last = false;
	uint64_t last_line = 0, last_file = 0;

	/* Time to run the line program. */
	uint8_t opcode;
	while (read_u8(&unit, &opcode)) {
		bool emit = false, reset_basic_block = false;

		if (opcode >= opcode_base) {
			/* "Special" opcodes. */
			uint8_t diff = opcode - opcode_base;
			address += diff / line_range;
			line += line_base + diff % line_range;
			emit = true;
		} else if (opcode == 0) {
			/* "Extended" opcodes. */
			uint64_t extsize;
			struct dwbuf extra;
			if (!read_uleb128(&unit, &extsize) ||
			    !read_buf(&unit, &extra, extsize) ||
			    !read_u8(&extra, &opcode))
				goto next;
			switch (opcode) {
			case DW_LNE_end_sequence:
				emit = true;
				end_sequence = true;
				break;
			case DW_LNE_set_address:
				switch (extra.len) {
				case 4: {
					uint32_t address32;
					if (!read_u32(&extra, &address32))
						goto next;
					address = address32;
					break;
				}
				case 8:
					if (!read_u64(&extra, &address))
						goto next;
					break;
				default:
					DWARN("unexpected address length: %zu",
					    extra.len);
					goto next;
				}
				break;
			case DW_LNE_define_file:
				/* XXX: hope this isn't needed */
			default:
				DWARN("unknown extended opcode: %d", opcode);
				goto next;
			}
		} else {
			/* "Standard" opcodes. */
			switch (opcode) {
			case DW_LNS_copy:
				emit = true;
				reset_basic_block = true;
				break;
			case DW_LNS_advance_pc: {
				uint64_t delta;
				if (!read_uleb128(&unit, &delta))
					goto next;
				address += delta * min_insn_length;
				break;
			}
			case DW_LNS_advance_line: {
				int64_t delta;
				if (!read_sleb128(&unit, &delta))
					goto next;
				line += delta;
				break;
			}
			case DW_LNS_set_file:
				if (!read_uleb128(&unit, &file))
					goto next;
				break;
			case DW_LNS_set_column:
				if (!read_uleb128(&unit, &column))
					goto next;
				break;
			case DW_LNS_negate_stmt:
				is_stmt = !is_stmt;
				break;
			case DW_LNS_set_basic_block:
				basic_block = true;
				break;
			case DW_LNS_const_add_pc:
				address += (255 - opcode_base) / line_range;
				break;
			case DW_LNS_set_prologue_end:
				prologue_end = true;
				break;
			case DW_LNS_set_epilogue_begin:
				epilogue_begin = true;
				break;
			default:
				DWARN("unknown standard opcode: %d", opcode);
				goto next;
			}
		}

		if (emit) {
			if (address > pc) {
				/* Found an entry after our target PC. */
				if (!have_last) {
					/* Give up on this program. */
					break;
				}
				/* Return the last entry. */
				*outline = last_line;
				return (read_filename(&names, outdirname,
				    outbasename, opcode_base, file));
			}

			last_file = file;
			last_line = line;
			have_last = true;
		}

		if (reset_basic_block)
			basic_block = false;
	}

	goto next;
}
예제 #7
0
파일: dwarf2expr.c 프로젝트: DonCN/haiku
static void
execute_stack_op (struct dwarf_expr_context *ctx, unsigned char *op_ptr,
		  unsigned char *op_end)
{
  ctx->in_reg = 0;

  while (op_ptr < op_end)
    {
      enum dwarf_location_atom op = *op_ptr++;
      CORE_ADDR result;
      ULONGEST uoffset, reg;
      LONGEST offset;
      int bytes_read;

      switch (op)
	{
	case DW_OP_lit0:
	case DW_OP_lit1:
	case DW_OP_lit2:
	case DW_OP_lit3:
	case DW_OP_lit4:
	case DW_OP_lit5:
	case DW_OP_lit6:
	case DW_OP_lit7:
	case DW_OP_lit8:
	case DW_OP_lit9:
	case DW_OP_lit10:
	case DW_OP_lit11:
	case DW_OP_lit12:
	case DW_OP_lit13:
	case DW_OP_lit14:
	case DW_OP_lit15:
	case DW_OP_lit16:
	case DW_OP_lit17:
	case DW_OP_lit18:
	case DW_OP_lit19:
	case DW_OP_lit20:
	case DW_OP_lit21:
	case DW_OP_lit22:
	case DW_OP_lit23:
	case DW_OP_lit24:
	case DW_OP_lit25:
	case DW_OP_lit26:
	case DW_OP_lit27:
	case DW_OP_lit28:
	case DW_OP_lit29:
	case DW_OP_lit30:
	case DW_OP_lit31:
	  result = op - DW_OP_lit0;
	  break;

	case DW_OP_addr:
	  result = dwarf2_read_address (op_ptr, op_end, &bytes_read);
	  op_ptr += bytes_read;
	  break;

	case DW_OP_const1u:
	  result = extract_unsigned_integer (op_ptr, 1);
	  op_ptr += 1;
	  break;
	case DW_OP_const1s:
	  result = extract_signed_integer (op_ptr, 1);
	  op_ptr += 1;
	  break;
	case DW_OP_const2u:
	  result = extract_unsigned_integer (op_ptr, 2);
	  op_ptr += 2;
	  break;
	case DW_OP_const2s:
	  result = extract_signed_integer (op_ptr, 2);
	  op_ptr += 2;
	  break;
	case DW_OP_const4u:
	  result = extract_unsigned_integer (op_ptr, 4);
	  op_ptr += 4;
	  break;
	case DW_OP_const4s:
	  result = extract_signed_integer (op_ptr, 4);
	  op_ptr += 4;
	  break;
	case DW_OP_const8u:
	  result = extract_unsigned_integer (op_ptr, 8);
	  op_ptr += 8;
	  break;
	case DW_OP_const8s:
	  result = extract_signed_integer (op_ptr, 8);
	  op_ptr += 8;
	  break;
	case DW_OP_constu:
	  op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
	  result = uoffset;
	  break;
	case DW_OP_consts:
	  op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	  result = offset;
	  break;

	/* The DW_OP_reg operations are required to occur alone in
	   location expressions.  */
	case DW_OP_reg0:
	case DW_OP_reg1:
	case DW_OP_reg2:
	case DW_OP_reg3:
	case DW_OP_reg4:
	case DW_OP_reg5:
	case DW_OP_reg6:
	case DW_OP_reg7:
	case DW_OP_reg8:
	case DW_OP_reg9:
	case DW_OP_reg10:
	case DW_OP_reg11:
	case DW_OP_reg12:
	case DW_OP_reg13:
	case DW_OP_reg14:
	case DW_OP_reg15:
	case DW_OP_reg16:
	case DW_OP_reg17:
	case DW_OP_reg18:
	case DW_OP_reg19:
	case DW_OP_reg20:
	case DW_OP_reg21:
	case DW_OP_reg22:
	case DW_OP_reg23:
	case DW_OP_reg24:
	case DW_OP_reg25:
	case DW_OP_reg26:
	case DW_OP_reg27:
	case DW_OP_reg28:
	case DW_OP_reg29:
	case DW_OP_reg30:
	case DW_OP_reg31:
	  if (op_ptr != op_end && *op_ptr != DW_OP_piece)
	    error ("DWARF-2 expression error: DW_OP_reg operations must be "
		   "used either alone or in conjuction with DW_OP_piece.");

	  result = op - DW_OP_reg0;
	  ctx->in_reg = 1;

	  break;

	case DW_OP_regx:
	  op_ptr = read_uleb128 (op_ptr, op_end, &reg);
	  if (op_ptr != op_end && *op_ptr != DW_OP_piece)
	    error ("DWARF-2 expression error: DW_OP_reg operations must be "
		   "used either alone or in conjuction with DW_OP_piece.");

	  result = reg;
	  ctx->in_reg = 1;
	  break;

	case DW_OP_breg0:
	case DW_OP_breg1:
	case DW_OP_breg2:
	case DW_OP_breg3:
	case DW_OP_breg4:
	case DW_OP_breg5:
	case DW_OP_breg6:
	case DW_OP_breg7:
	case DW_OP_breg8:
	case DW_OP_breg9:
	case DW_OP_breg10:
	case DW_OP_breg11:
	case DW_OP_breg12:
	case DW_OP_breg13:
	case DW_OP_breg14:
	case DW_OP_breg15:
	case DW_OP_breg16:
	case DW_OP_breg17:
	case DW_OP_breg18:
	case DW_OP_breg19:
	case DW_OP_breg20:
	case DW_OP_breg21:
	case DW_OP_breg22:
	case DW_OP_breg23:
	case DW_OP_breg24:
	case DW_OP_breg25:
	case DW_OP_breg26:
	case DW_OP_breg27:
	case DW_OP_breg28:
	case DW_OP_breg29:
	case DW_OP_breg30:
	case DW_OP_breg31:
	  {
	    op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	    result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0);
	    result += offset;
	  }
	  break;
	case DW_OP_bregx:
	  {
	    op_ptr = read_uleb128 (op_ptr, op_end, &reg);
	    op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	    result = (ctx->read_reg) (ctx->baton, reg);
	    result += offset;
	  }
	  break;
	case DW_OP_fbreg:
	  {
	    unsigned char *datastart;
	    size_t datalen;
	    unsigned int before_stack_len;

	    op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	    /* Rather than create a whole new context, we simply
	       record the stack length before execution, then reset it
	       afterwards, effectively erasing whatever the recursive
	       call put there.  */
	    before_stack_len = ctx->stack_len;
	    /* FIXME: cagney/2003-03-26: This code should be using
               get_frame_base_address(), and then implement a dwarf2
               specific this_base method.  */
	    (ctx->get_frame_base) (ctx->baton, &datastart, &datalen);
	    dwarf_expr_eval (ctx, datastart, datalen);
	    result = dwarf_expr_fetch (ctx, 0);
	    if (ctx->in_reg)
	      result = (ctx->read_reg) (ctx->baton, result);
	    result = result + offset;
	    ctx->stack_len = before_stack_len;
	    ctx->in_reg = 0;
	  }
	  break;
	case DW_OP_dup:
	  result = dwarf_expr_fetch (ctx, 0);
	  break;

	case DW_OP_drop:
	  dwarf_expr_pop (ctx);
	  goto no_push;

	case DW_OP_pick:
	  offset = *op_ptr++;
	  result = dwarf_expr_fetch (ctx, offset);
	  break;

	case DW_OP_over:
	  result = dwarf_expr_fetch (ctx, 1);
	  break;

	case DW_OP_rot:
	  {
	    CORE_ADDR t1, t2, t3;

	    if (ctx->stack_len < 3)
	       error ("Not enough elements for DW_OP_rot. Need 3, have %d\n",
		      ctx->stack_len);
	    t1 = ctx->stack[ctx->stack_len - 1];
	    t2 = ctx->stack[ctx->stack_len - 2];
	    t3 = ctx->stack[ctx->stack_len - 3];
	    ctx->stack[ctx->stack_len - 1] = t2;
	    ctx->stack[ctx->stack_len - 2] = t3;
	    ctx->stack[ctx->stack_len - 3] = t1;
	    goto no_push;
	  }

	case DW_OP_deref:
	case DW_OP_deref_size:
	case DW_OP_abs:
	case DW_OP_neg:
	case DW_OP_not:
	case DW_OP_plus_uconst:
	  /* Unary operations.  */
	  result = dwarf_expr_fetch (ctx, 0);
	  dwarf_expr_pop (ctx);

	  switch (op)
	    {
	    case DW_OP_deref:
	      {
		char *buf = alloca (TARGET_ADDR_BIT / TARGET_CHAR_BIT);
		int bytes_read;

		(ctx->read_mem) (ctx->baton, buf, result,
				 TARGET_ADDR_BIT / TARGET_CHAR_BIT);
		result = dwarf2_read_address (buf,
					      buf + (TARGET_ADDR_BIT
						     / TARGET_CHAR_BIT),
					      &bytes_read);
	      }
	      break;

	    case DW_OP_deref_size:
	      {
		char *buf = alloca (TARGET_ADDR_BIT / TARGET_CHAR_BIT);
		int bytes_read;

		(ctx->read_mem) (ctx->baton, buf, result, *op_ptr++);
		result = dwarf2_read_address (buf,
					      buf + (TARGET_ADDR_BIT
						     / TARGET_CHAR_BIT),
					      &bytes_read);
	      }
	      break;

	    case DW_OP_abs:
	      if ((signed int) result < 0)
		result = -result;
	      break;
	    case DW_OP_neg:
	      result = -result;
	      break;
	    case DW_OP_not:
	      result = ~result;
	      break;
	    case DW_OP_plus_uconst:
	      op_ptr = read_uleb128 (op_ptr, op_end, &reg);
	      result += reg;
	      break;
	    }
	  break;

	case DW_OP_and:
	case DW_OP_div:
	case DW_OP_minus:
	case DW_OP_mod:
	case DW_OP_mul:
	case DW_OP_or:
	case DW_OP_plus:
	case DW_OP_shl:
	case DW_OP_shr:
	case DW_OP_shra:
	case DW_OP_xor:
	case DW_OP_le:
	case DW_OP_ge:
	case DW_OP_eq:
	case DW_OP_lt:
	case DW_OP_gt:
	case DW_OP_ne:
	  {
	    /* Binary operations.  Use the value engine to do computations in
	       the right width.  */
	    CORE_ADDR first, second;
	    enum exp_opcode binop;
	    struct value *val1, *val2;

	    second = dwarf_expr_fetch (ctx, 0);
	    dwarf_expr_pop (ctx);

	    first = dwarf_expr_fetch (ctx, 0);
	    dwarf_expr_pop (ctx);

	    val1 = value_from_longest (unsigned_address_type (), first);
	    val2 = value_from_longest (unsigned_address_type (), second);

	    switch (op)
	      {
	      case DW_OP_and:
		binop = BINOP_BITWISE_AND;
		break;
	      case DW_OP_div:
		binop = BINOP_DIV;
                break;
	      case DW_OP_minus:
		binop = BINOP_SUB;
		break;
	      case DW_OP_mod:
		binop = BINOP_MOD;
		break;
	      case DW_OP_mul:
		binop = BINOP_MUL;
		break;
	      case DW_OP_or:
		binop = BINOP_BITWISE_IOR;
		break;
	      case DW_OP_plus:
		binop = BINOP_ADD;
		break;
	      case DW_OP_shl:
		binop = BINOP_LSH;
		break;
	      case DW_OP_shr:
		binop = BINOP_RSH;
                break;
	      case DW_OP_shra:
		binop = BINOP_RSH;
		val1 = value_from_longest (signed_address_type (), first);
		break;
	      case DW_OP_xor:
		binop = BINOP_BITWISE_XOR;
		break;
	      case DW_OP_le:
		binop = BINOP_LEQ;
		break;
	      case DW_OP_ge:
		binop = BINOP_GEQ;
		break;
	      case DW_OP_eq:
		binop = BINOP_EQUAL;
		break;
	      case DW_OP_lt:
		binop = BINOP_LESS;
		break;
	      case DW_OP_gt:
		binop = BINOP_GTR;
		break;
	      case DW_OP_ne:
		binop = BINOP_NOTEQUAL;
		break;
	      default:
		internal_error (__FILE__, __LINE__,
				"Can't be reached.");
	      }
	    result = value_as_long (value_binop (val1, val2, binop));
	  }
	  break;

	case DW_OP_GNU_push_tls_address:
	  /* Variable is at a constant offset in the thread-local
	  storage block into the objfile for the current thread and
	  the dynamic linker module containing this expression. Here
	  we return returns the offset from that base.  The top of the
	  stack has the offset from the beginning of the thread
	  control block at which the variable is located.  Nothing
	  should follow this operator, so the top of stack would be
	  returned.  */
	  result = dwarf_expr_fetch (ctx, 0);
	  dwarf_expr_pop (ctx);
	  result = (ctx->get_tls_address) (ctx->baton, result);
	  break;

	case DW_OP_skip:
	  offset = extract_signed_integer (op_ptr, 2);
	  op_ptr += 2;
	  op_ptr += offset;
	  goto no_push;

	case DW_OP_bra:
	  offset = extract_signed_integer (op_ptr, 2);
	  op_ptr += 2;
	  if (dwarf_expr_fetch (ctx, 0) != 0)
	    op_ptr += offset;
	  dwarf_expr_pop (ctx);
	  goto no_push;

	case DW_OP_nop:
	  goto no_push;

        case DW_OP_piece:
          {
            ULONGEST size;
            CORE_ADDR addr_or_regnum;

            /* Record the piece.  */
            op_ptr = read_uleb128 (op_ptr, op_end, &size);
            addr_or_regnum = dwarf_expr_fetch (ctx, 0);
            add_piece (ctx, ctx->in_reg, addr_or_regnum, size);

            /* Pop off the address/regnum, and clear the in_reg flag.  */
            dwarf_expr_pop (ctx);
            ctx->in_reg = 0;
          }
          goto no_push;

	default:
	  error ("Unhandled dwarf expression opcode 0x%x", op);
	}

      /* Most things push a result value.  */
      dwarf_expr_push (ctx, result);
    no_push:;
    }
}
예제 #8
0
static void
get_action_description_for (_Unwind_Context *uw_context,
                            _Unwind_Exception *uw_exception,
                            region_descriptor *region,
                            action_descriptor *action)
{
  _GNAT_Exception * gnat_exception = (_GNAT_Exception *) uw_exception;

  /* Search the call site table first, which may get us a landing pad as well
     as the head of an action record list.  */
  get_call_site_action_for (uw_context, region, action);
  db_action_for (action, uw_context);

  /* If there is not even a call_site entry, we are done.  */
  if (action->kind == nothing)
    return;

  /* Otherwise, check what we have at the place of the call site  */

  /* No landing pad => no cleanups or handlers.  */
  if (action->landing_pad == 0)
    {
      action->kind = nothing;
      return;
    }

  /* Landing pad + null table entry => only cleanups.  */
  else if (action->table_entry == 0)
    {
      action->kind = cleanup;
      return;
    }

  /* Landing pad + Table entry => handlers + possible cleanups.  */
  else
    {
      const unsigned char * p = action->table_entry;

      _Unwind_Sword ar_filter, ar_disp;

      action->kind = nothing;

      while (1)
	{
	  p = read_sleb128 (p, &ar_filter);
	  read_sleb128 (p, &ar_disp);
	  /* Don't assign p here, as it will be incremented by ar_disp
	     below.  */

	  /* Null filters are for cleanups. */
	  if (ar_filter == 0)
	    action->kind = cleanup;

	  /* Positive filters are for regular handlers.  */
	  else if (ar_filter > 0)
	    {
	      /* See if the filter we have is for an exception which matches
		 the one we are propagating.  */
	      _Unwind_Ptr eid = get_ttype_entry_for (region, ar_filter);

	      if (eid == gnat_exception->id
		  || eid == GNAT_ALL_OTHERS
		  || (eid == GNAT_OTHERS && gnat_exception->handled_by_others))
		{
		  action->ttype_filter = ar_filter;
		  action->ttype_entry = eid;
		  action->kind = handler;
		  return;
		}
	    }

	  /* Negative filter values are for C++ exception specifications.
	     Should not be there for Ada :/  */
	  else
	    db (DB_ERR, "========> Err, filter < 0 for Ada/dwarf\n");

	  if (ar_disp == 0)
	    return;

	  p += ar_disp;
	}
    }
}
static void
dwarf2_tracepoint_var_ref (struct symbol *symbol, struct agent_expr *ax,
			   struct axs_value *value, gdb_byte *data,
			   int size)
{
  if (size == 0)
    error (_("Symbol \"%s\" has been optimized out."),
	   SYMBOL_PRINT_NAME (symbol));

  if (size == 1
      && data[0] >= DW_OP_reg0
      && data[0] <= DW_OP_reg31)
    {
      value->kind = axs_lvalue_register;
      value->u.reg = data[0] - DW_OP_reg0;
    }
  else if (data[0] == DW_OP_regx)
    {
      ULONGEST reg;
      read_uleb128 (data + 1, data + size, &reg);
      value->kind = axs_lvalue_register;
      value->u.reg = reg;
    }
  else if (data[0] == DW_OP_fbreg)
    {
      /* And this is worse than just minimal; we should honor the frame base
	 as above.  */
      int frame_reg;
      LONGEST frame_offset;
      gdb_byte *buf_end;

      buf_end = read_sleb128 (data + 1, data + size, &frame_offset);
      if (buf_end != data + size)
	error (_("Unexpected opcode after DW_OP_fbreg for symbol \"%s\"."),
	       SYMBOL_PRINT_NAME (symbol));

      gdbarch_virtual_frame_pointer (current_gdbarch, 
				     ax->scope, &frame_reg, &frame_offset);
      ax_reg (ax, frame_reg);
      ax_const_l (ax, frame_offset);
      ax_simple (ax, aop_add);

      value->kind = axs_lvalue_memory;
    }
  else if (data[0] >= DW_OP_breg0
	   && data[0] <= DW_OP_breg31)
    {
      unsigned int reg;
      LONGEST offset;
      gdb_byte *buf_end;

      reg = data[0] - DW_OP_breg0;
      buf_end = read_sleb128 (data + 1, data + size, &offset);
      if (buf_end != data + size)
	error (_("Unexpected opcode after DW_OP_breg%u for symbol \"%s\"."),
	       reg, SYMBOL_PRINT_NAME (symbol));

      ax_reg (ax, reg);
      ax_const_l (ax, offset);
      ax_simple (ax, aop_add);

      value->kind = axs_lvalue_memory;
    }
  else
    error (_("Unsupported DWARF opcode 0x%x in the location of \"%s\"."),
	   data[0], SYMBOL_PRINT_NAME (symbol));
}
예제 #10
0
bfd_boolean
_bfd_elf_discard_section_eh_frame
   (bfd *abfd, struct bfd_link_info *info, asection *sec,
    bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
    struct elf_reloc_cookie *cookie)
{
#define REQUIRE(COND)					\
  do							\
    if (!(COND))					\
      goto free_no_table;				\
  while (0)

  bfd_byte *ehbuf = NULL, *buf;
  bfd_byte *last_cie, *last_fde;
  struct eh_cie_fde *ent, *last_cie_inf, *this_inf;
  struct cie_header hdr;
  struct cie cie;
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  struct eh_frame_sec_info *sec_info = NULL;
  unsigned int cie_usage_count, offset;
  unsigned int ptr_size;

  if (sec->size == 0)
    {
      /* This file does not contain .eh_frame information.  */
      return FALSE;
    }

  if ((sec->output_section != NULL
       && bfd_is_abs_section (sec->output_section)))
    {
      /* At least one of the sections is being discarded from the
	 link, so we should just ignore them.  */
      return FALSE;
    }

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  /* Read the frame unwind information from abfd.  */

  REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf));

  if (sec->size >= 4
      && bfd_get_32 (abfd, ehbuf) == 0
      && cookie->rel == cookie->relend)
    {
      /* Empty .eh_frame section.  */
      free (ehbuf);
      return FALSE;
    }

  /* If .eh_frame section size doesn't fit into int, we cannot handle
     it (it would need to use 64-bit .eh_frame format anyway).  */
  REQUIRE (sec->size == (unsigned int) sec->size);

  ptr_size = (get_elf_backend_data (abfd)
	      ->elf_backend_eh_frame_address_size (abfd, sec));
  REQUIRE (ptr_size != 0);

  buf = ehbuf;
  last_cie = NULL;
  last_cie_inf = NULL;
  memset (&cie, 0, sizeof (cie));
  cie_usage_count = 0;
  sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info)
			  + 99 * sizeof (struct eh_cie_fde));
  REQUIRE (sec_info);

  sec_info->alloced = 100;

#define ENSURE_NO_RELOCS(buf)				\
  REQUIRE (!(cookie->rel < cookie->relend		\
	     && (cookie->rel->r_offset			\
		 < (bfd_size_type) ((buf) - ehbuf))	\
	     && cookie->rel->r_info != 0))

#define SKIP_RELOCS(buf)				\
  while (cookie->rel < cookie->relend			\
	 && (cookie->rel->r_offset			\
	     < (bfd_size_type) ((buf) - ehbuf)))	\
    cookie->rel++

#define GET_RELOC(buf)					\
  ((cookie->rel < cookie->relend			\
    && (cookie->rel->r_offset				\
	== (bfd_size_type) ((buf) - ehbuf)))		\
   ? cookie->rel : NULL)

  for (;;)
    {
      char *aug;
      bfd_byte *start, *end, *insns;
      bfd_size_type length;

      if (sec_info->count == sec_info->alloced)
	{
	  struct eh_cie_fde *old_entry = sec_info->entry;
	  sec_info = bfd_realloc (sec_info,
				  sizeof (struct eh_frame_sec_info)
				  + ((sec_info->alloced + 99)
				     * sizeof (struct eh_cie_fde)));
	  REQUIRE (sec_info);

	  memset (&sec_info->entry[sec_info->alloced], 0,
		  100 * sizeof (struct eh_cie_fde));
	  sec_info->alloced += 100;

	  /* Now fix any pointers into the array.  */
	  if (last_cie_inf >= old_entry
	      && last_cie_inf < old_entry + sec_info->count)
	    last_cie_inf = sec_info->entry + (last_cie_inf - old_entry);
	}

      this_inf = sec_info->entry + sec_info->count;
      last_fde = buf;
      /* If we are at the end of the section, we still need to decide
	 on whether to output or discard last encountered CIE (if any).  */
      if ((bfd_size_type) (buf - ehbuf) == sec->size)
	{
	  hdr.length = 0;
	  hdr.id = (unsigned int) -1;
	  end = buf;
	}
      else
	{
	  /* Read the length of the entry.  */
	  REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4));
	  hdr.length = bfd_get_32 (abfd, buf - 4);

	  /* 64-bit .eh_frame is not supported.  */
	  REQUIRE (hdr.length != 0xffffffff);

	  /* The CIE/FDE must be fully contained in this input section.  */
	  REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr.length <= sec->size);
	  end = buf + hdr.length;

	  this_inf->offset = last_fde - ehbuf;
	  this_inf->size = 4 + hdr.length;

	  if (hdr.length == 0)
	    {
	      /* A zero-length CIE should only be found at the end of
		 the section.  */
	      REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size);
	      ENSURE_NO_RELOCS (buf);
	      sec_info->count++;
	      /* Now just finish last encountered CIE processing and break
		 the loop.  */
	      hdr.id = (unsigned int) -1;
	    }
	  else
	    {
	      REQUIRE (skip_bytes (&buf, end, 4));
	      hdr.id = bfd_get_32 (abfd, buf - 4);
	      REQUIRE (hdr.id != (unsigned int) -1);
	    }
	}

      if (hdr.id == 0 || hdr.id == (unsigned int) -1)
	{
	  unsigned int initial_insn_length;

	  /* CIE  */
	  if (last_cie != NULL)
	    {
	      /* Now check if this CIE is identical to the last CIE,
		 in which case we can remove it provided we adjust
		 all FDEs.  Also, it can be removed if we have removed
		 all FDEs using it.  */
	      if ((!info->relocatable
		   && hdr_info->last_cie_sec
		   && (sec->output_section
		       == hdr_info->last_cie_sec->output_section)
		   && cie_compare (&cie, &hdr_info->last_cie) == 0)
		  || cie_usage_count == 0)
		last_cie_inf->removed = 1;
	      else
		{
		  hdr_info->last_cie = cie;
		  hdr_info->last_cie_sec = sec;
		  last_cie_inf->make_relative = cie.make_relative;
		  last_cie_inf->make_lsda_relative = cie.make_lsda_relative;
		  last_cie_inf->per_encoding_relative
		    = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel;
		}
	    }

	  if (hdr.id == (unsigned int) -1)
	    break;

	  last_cie_inf = this_inf;
	  this_inf->cie = 1;

	  cie_usage_count = 0;
	  memset (&cie, 0, sizeof (cie));
	  cie.hdr = hdr;
	  REQUIRE (read_byte (&buf, end, &cie.version));

	  /* Cannot handle unknown versions.  */
	  REQUIRE (cie.version == 1 || cie.version == 3);
	  REQUIRE (strlen ((char *) buf) < sizeof (cie.augmentation));

	  strcpy (cie.augmentation, (char *) buf);
	  buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1;
	  ENSURE_NO_RELOCS (buf);
	  if (buf[0] == 'e' && buf[1] == 'h')
	    {
	      /* GCC < 3.0 .eh_frame CIE */
	      /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__
		 is private to each CIE, so we don't need it for anything.
		 Just skip it.  */
	      REQUIRE (skip_bytes (&buf, end, ptr_size));
	      SKIP_RELOCS (buf);
	    }
	  REQUIRE (read_uleb128 (&buf, end, &cie.code_align));
	  REQUIRE (read_sleb128 (&buf, end, &cie.data_align));
	  if (cie.version == 1)
	    {
	      REQUIRE (buf < end);
	      cie.ra_column = *buf++;
	    }
	  else
	    REQUIRE (read_uleb128 (&buf, end, &cie.ra_column));
	  ENSURE_NO_RELOCS (buf);
	  cie.lsda_encoding = DW_EH_PE_omit;
	  cie.fde_encoding = DW_EH_PE_omit;
	  cie.per_encoding = DW_EH_PE_omit;
	  aug = cie.augmentation;
	  if (aug[0] != 'e' || aug[1] != 'h')
	    {
	      if (*aug == 'z')
		{
		  aug++;
		  REQUIRE (read_uleb128 (&buf, end, &cie.augmentation_size));
	  	  ENSURE_NO_RELOCS (buf);
		}

	      while (*aug != '\0')
		switch (*aug++)
		  {
		  case 'L':
		    REQUIRE (read_byte (&buf, end, &cie.lsda_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size));
		    break;
		  case 'R':
		    REQUIRE (read_byte (&buf, end, &cie.fde_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie.fde_encoding, ptr_size));
		    break;
		  case 'P':
		    {
		      int per_width;

		      REQUIRE (read_byte (&buf, end, &cie.per_encoding));
		      per_width = get_DW_EH_PE_width (cie.per_encoding,
						      ptr_size);
		      REQUIRE (per_width);
		      if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned)
			{
			  length = -(buf - ehbuf) & (per_width - 1);
			  REQUIRE (skip_bytes (&buf, end, length));
			}
		      ENSURE_NO_RELOCS (buf);
		      /* Ensure we have a reloc here, against
			 a global symbol.  */
		      if (GET_RELOC (buf) != NULL)
			{
			  unsigned long r_symndx;

#ifdef BFD64
			  if (ptr_size == 8)
			    r_symndx = ELF64_R_SYM (cookie->rel->r_info);
			  else
#endif
			    r_symndx = ELF32_R_SYM (cookie->rel->r_info);
			  if (r_symndx >= cookie->locsymcount)
			    {
			      struct elf_link_hash_entry *h;

			      r_symndx -= cookie->extsymoff;
			      h = cookie->sym_hashes[r_symndx];

			      while (h->root.type == bfd_link_hash_indirect
				     || h->root.type == bfd_link_hash_warning)
				h = (struct elf_link_hash_entry *)
				    h->root.u.i.link;

			      cie.personality = h;
			    }
			  /* Cope with MIPS-style composite relocations.  */
			  do
			    cookie->rel++;
			  while (GET_RELOC (buf) != NULL);
			}
		      REQUIRE (skip_bytes (&buf, end, per_width));
		    }
		    break;
		  default:
		    /* Unrecognized augmentation. Better bail out.  */
		    goto free_no_table;
		  }
	    }

	  /* For shared libraries, try to get rid of as many RELATIVE relocs
	     as possible.  */
	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_relative_eh_frame
		  (abfd, info, sec)))
	    {
	      if ((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr)
		cie.make_relative = 1;
	      /* If the CIE doesn't already have an 'R' entry, it's fairly
		 easy to add one, provided that there's no aligned data
		 after the augmentation string.  */
	      else if (cie.fde_encoding == DW_EH_PE_omit
		       && (cie.per_encoding & 0xf0) != DW_EH_PE_aligned)
		{
		  if (*cie.augmentation == 0)
		    this_inf->add_augmentation_size = 1;
		  this_inf->add_fde_encoding = 1;
		  cie.make_relative = 1;
		}
	    }

	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_lsda_relative_eh_frame
		  (abfd, info, sec))
	      && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr)
	    cie.make_lsda_relative = 1;

	  /* If FDE encoding was not specified, it defaults to
	     DW_EH_absptr.  */
	  if (cie.fde_encoding == DW_EH_PE_omit)
	    cie.fde_encoding = DW_EH_PE_absptr;

	  initial_insn_length = end - buf;
	  if (initial_insn_length <= 50)
	    {
	      cie.initial_insn_length = initial_insn_length;
	      memcpy (cie.initial_instructions, buf, initial_insn_length);
	    }
	  insns = buf;
	  buf += initial_insn_length;
	  ENSURE_NO_RELOCS (buf);
	  last_cie = last_fde;
	}
      else
	{
	  /* Ensure this FDE uses the last CIE encountered.  */
	  REQUIRE (last_cie);
	  REQUIRE (hdr.id == (unsigned int) (buf - 4 - last_cie));

	  ENSURE_NO_RELOCS (buf);
	  REQUIRE (GET_RELOC (buf));

	  if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie))
	    /* This is a FDE against a discarded section.  It should
	       be deleted.  */
	    this_inf->removed = 1;
	  else
	    {
	      if (info->shared
		  && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr
		       && cie.make_relative == 0)
		      || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned))
		{
		  /* If a shared library uses absolute pointers
		     which we cannot turn into PC relative,
		     don't create the binary search table,
		     since it is affected by runtime relocations.  */
		  hdr_info->table = FALSE;
		}
	      cie_usage_count++;
	      hdr_info->fde_count++;
	    }
	  /* Skip the initial location and address range.  */
	  start = buf;
	  length = get_DW_EH_PE_width (cie.fde_encoding, ptr_size);
	  REQUIRE (skip_bytes (&buf, end, 2 * length));

	  /* Skip the augmentation size, if present.  */
	  if (cie.augmentation[0] == 'z')
	    REQUIRE (read_uleb128 (&buf, end, &length));
	  else
	    length = 0;

	  /* Of the supported augmentation characters above, only 'L'
	     adds augmentation data to the FDE.  This code would need to
	     be adjusted if any future augmentations do the same thing.  */
	  if (cie.lsda_encoding != DW_EH_PE_omit)
	    {
	      this_inf->lsda_offset = buf - start;
	      /* If there's no 'z' augmentation, we don't know where the
		 CFA insns begin.  Assume no padding.  */
	      if (cie.augmentation[0] != 'z')
		length = end - buf;
	    }

	  /* Skip over the augmentation data.  */
	  REQUIRE (skip_bytes (&buf, end, length));
	  insns = buf;

	  buf = last_fde + 4 + hdr.length;
	  SKIP_RELOCS (buf);
	}

      /* Try to interpret the CFA instructions and find the first
	 padding nop.  Shrink this_inf's size so that it doesn't
	 including the padding.  */
      length = get_DW_EH_PE_width (cie.fde_encoding, ptr_size);
      insns = skip_non_nops (insns, end, length);
      if (insns != 0)
	this_inf->size -= end - insns;

      this_inf->fde_encoding = cie.fde_encoding;
      this_inf->lsda_encoding = cie.lsda_encoding;
      sec_info->count++;
    }

  elf_section_data (sec)->sec_info = sec_info;
  sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME;

  /* Ok, now we can assign new offsets.  */
  offset = 0;
  last_cie_inf = hdr_info->last_cie_inf;
  for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
    if (!ent->removed)
      {
	if (ent->cie)
	  last_cie_inf = ent;
	else
	  ent->cie_inf = last_cie_inf;
	ent->new_offset = offset;
	offset += size_of_output_cie_fde (ent, ptr_size);
      }
  hdr_info->last_cie_inf = last_cie_inf;

  /* Resize the sec as needed.  */
  sec->rawsize = sec->size;
  sec->size = offset;
  if (sec->size == 0)
    sec->flags |= SEC_EXCLUDE;

  free (ehbuf);
  return offset != sec->rawsize;

free_no_table:
  if (ehbuf)
    free (ehbuf);
  if (sec_info)
    free (sec_info);
  hdr_info->table = FALSE;
  hdr_info->last_cie.hdr.length = 0;
  return FALSE;

#undef REQUIRE
}
예제 #11
0
static void
execute_stack_op (struct dwarf_expr_context *ctx,
		  gdb_byte *op_ptr, gdb_byte *op_end)
{
  enum bfd_endian byte_order = gdbarch_byte_order (ctx->gdbarch);
  ctx->location = DWARF_VALUE_MEMORY;
  ctx->initialized = 1;  /* Default is initialized.  */

  if (ctx->recursion_depth > ctx->max_recursion_depth)
    error (_("DWARF-2 expression error: Loop detected (%d)."),
	   ctx->recursion_depth);
  ctx->recursion_depth++;

  while (op_ptr < op_end)
    {
      enum dwarf_location_atom op = *op_ptr++;
      CORE_ADDR result;
      /* Assume the value is not in stack memory.
	 Code that knows otherwise sets this to 1.
	 Some arithmetic on stack addresses can probably be assumed to still
	 be a stack address, but we skip this complication for now.
	 This is just an optimization, so it's always ok to punt
	 and leave this as 0.  */
      int in_stack_memory = 0;
      ULONGEST uoffset, reg;
      LONGEST offset;

      switch (op)
	{
	case DW_OP_lit0:
	case DW_OP_lit1:
	case DW_OP_lit2:
	case DW_OP_lit3:
	case DW_OP_lit4:
	case DW_OP_lit5:
	case DW_OP_lit6:
	case DW_OP_lit7:
	case DW_OP_lit8:
	case DW_OP_lit9:
	case DW_OP_lit10:
	case DW_OP_lit11:
	case DW_OP_lit12:
	case DW_OP_lit13:
	case DW_OP_lit14:
	case DW_OP_lit15:
	case DW_OP_lit16:
	case DW_OP_lit17:
	case DW_OP_lit18:
	case DW_OP_lit19:
	case DW_OP_lit20:
	case DW_OP_lit21:
	case DW_OP_lit22:
	case DW_OP_lit23:
	case DW_OP_lit24:
	case DW_OP_lit25:
	case DW_OP_lit26:
	case DW_OP_lit27:
	case DW_OP_lit28:
	case DW_OP_lit29:
	case DW_OP_lit30:
	case DW_OP_lit31:
	  result = op - DW_OP_lit0;
	  break;

	case DW_OP_addr:
	  result = dwarf2_read_address (ctx->gdbarch,
					op_ptr, op_end, ctx->addr_size);
	  op_ptr += ctx->addr_size;
	  break;

	case DW_OP_const1u:
	  result = extract_unsigned_integer (op_ptr, 1, byte_order);
	  op_ptr += 1;
	  break;
	case DW_OP_const1s:
	  result = extract_signed_integer (op_ptr, 1, byte_order);
	  op_ptr += 1;
	  break;
	case DW_OP_const2u:
	  result = extract_unsigned_integer (op_ptr, 2, byte_order);
	  op_ptr += 2;
	  break;
	case DW_OP_const2s:
	  result = extract_signed_integer (op_ptr, 2, byte_order);
	  op_ptr += 2;
	  break;
	case DW_OP_const4u:
	  result = extract_unsigned_integer (op_ptr, 4, byte_order);
	  op_ptr += 4;
	  break;
	case DW_OP_const4s:
	  result = extract_signed_integer (op_ptr, 4, byte_order);
	  op_ptr += 4;
	  break;
	case DW_OP_const8u:
	  result = extract_unsigned_integer (op_ptr, 8, byte_order);
	  op_ptr += 8;
	  break;
	case DW_OP_const8s:
	  result = extract_signed_integer (op_ptr, 8, byte_order);
	  op_ptr += 8;
	  break;
	case DW_OP_constu:
	  op_ptr = read_uleb128 (op_ptr, op_end, &uoffset);
	  result = uoffset;
	  break;
	case DW_OP_consts:
	  op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	  result = offset;
	  break;

	/* The DW_OP_reg operations are required to occur alone in
	   location expressions.  */
	case DW_OP_reg0:
	case DW_OP_reg1:
	case DW_OP_reg2:
	case DW_OP_reg3:
	case DW_OP_reg4:
	case DW_OP_reg5:
	case DW_OP_reg6:
	case DW_OP_reg7:
	case DW_OP_reg8:
	case DW_OP_reg9:
	case DW_OP_reg10:
	case DW_OP_reg11:
	case DW_OP_reg12:
	case DW_OP_reg13:
	case DW_OP_reg14:
	case DW_OP_reg15:
	case DW_OP_reg16:
	case DW_OP_reg17:
	case DW_OP_reg18:
	case DW_OP_reg19:
	case DW_OP_reg20:
	case DW_OP_reg21:
	case DW_OP_reg22:
	case DW_OP_reg23:
	case DW_OP_reg24:
	case DW_OP_reg25:
	case DW_OP_reg26:
	case DW_OP_reg27:
	case DW_OP_reg28:
	case DW_OP_reg29:
	case DW_OP_reg30:
	case DW_OP_reg31:
	  if (op_ptr != op_end 
	      && *op_ptr != DW_OP_piece
	      && *op_ptr != DW_OP_GNU_uninit)
	    error (_("DWARF-2 expression error: DW_OP_reg operations must be "
		   "used either alone or in conjuction with DW_OP_piece."));

	  result = op - DW_OP_reg0;
	  ctx->location = DWARF_VALUE_REGISTER;
	  break;

	case DW_OP_regx:
	  op_ptr = read_uleb128 (op_ptr, op_end, &reg);
	  require_composition (op_ptr, op_end, "DW_OP_regx");

	  result = reg;
	  ctx->location = DWARF_VALUE_REGISTER;
	  break;

	case DW_OP_implicit_value:
	  {
	    ULONGEST len;
	    op_ptr = read_uleb128 (op_ptr, op_end, &len);
	    if (op_ptr + len > op_end)
	      error (_("DW_OP_implicit_value: too few bytes available."));
	    ctx->len = len;
	    ctx->data = op_ptr;
	    ctx->location = DWARF_VALUE_LITERAL;
	    op_ptr += len;
	    require_composition (op_ptr, op_end, "DW_OP_implicit_value");
	  }
	  goto no_push;

	case DW_OP_stack_value:
	  ctx->location = DWARF_VALUE_STACK;
	  require_composition (op_ptr, op_end, "DW_OP_stack_value");
	  goto no_push;

	case DW_OP_breg0:
	case DW_OP_breg1:
	case DW_OP_breg2:
	case DW_OP_breg3:
	case DW_OP_breg4:
	case DW_OP_breg5:
	case DW_OP_breg6:
	case DW_OP_breg7:
	case DW_OP_breg8:
	case DW_OP_breg9:
	case DW_OP_breg10:
	case DW_OP_breg11:
	case DW_OP_breg12:
	case DW_OP_breg13:
	case DW_OP_breg14:
	case DW_OP_breg15:
	case DW_OP_breg16:
	case DW_OP_breg17:
	case DW_OP_breg18:
	case DW_OP_breg19:
	case DW_OP_breg20:
	case DW_OP_breg21:
	case DW_OP_breg22:
	case DW_OP_breg23:
	case DW_OP_breg24:
	case DW_OP_breg25:
	case DW_OP_breg26:
	case DW_OP_breg27:
	case DW_OP_breg28:
	case DW_OP_breg29:
	case DW_OP_breg30:
	case DW_OP_breg31:
	  {
	    op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	    result = (ctx->read_reg) (ctx->baton, op - DW_OP_breg0);
	    result += offset;
	  }
	  break;
	case DW_OP_bregx:
	  {
	    op_ptr = read_uleb128 (op_ptr, op_end, &reg);
	    op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	    result = (ctx->read_reg) (ctx->baton, reg);
	    result += offset;
	  }
	  break;
	case DW_OP_fbreg:
	  {
	    gdb_byte *datastart;
	    size_t datalen;
	    unsigned int before_stack_len;

	    op_ptr = read_sleb128 (op_ptr, op_end, &offset);
	    /* Rather than create a whole new context, we simply
	       record the stack length before execution, then reset it
	       afterwards, effectively erasing whatever the recursive
	       call put there.  */
	    before_stack_len = ctx->stack_len;
	    /* FIXME: cagney/2003-03-26: This code should be using
               get_frame_base_address(), and then implement a dwarf2
               specific this_base method.  */
	    (ctx->get_frame_base) (ctx->baton, &datastart, &datalen);
	    dwarf_expr_eval (ctx, datastart, datalen);
	    if (ctx->location == DWARF_VALUE_LITERAL
		|| ctx->location == DWARF_VALUE_STACK)
	      error (_("Not implemented: computing frame base using explicit value operator"));
	    result = dwarf_expr_fetch (ctx, 0);
	    if (ctx->location == DWARF_VALUE_REGISTER)
	      result = (ctx->read_reg) (ctx->baton, result);
	    result = result + offset;
	    in_stack_memory = 1;
	    ctx->stack_len = before_stack_len;
	    ctx->location = DWARF_VALUE_MEMORY;
	  }
	  break;

	case DW_OP_dup:
	  result = dwarf_expr_fetch (ctx, 0);
	  in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 0);
	  break;

	case DW_OP_drop:
	  dwarf_expr_pop (ctx);
	  goto no_push;

	case DW_OP_pick:
	  offset = *op_ptr++;
	  result = dwarf_expr_fetch (ctx, offset);
	  in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, offset);
	  break;
	  
	case DW_OP_swap:
	  {
	    struct dwarf_stack_value t1, t2;

	    if (ctx->stack_len < 2)
	       error (_("Not enough elements for DW_OP_swap. Need 2, have %d."),
		      ctx->stack_len);
	    t1 = ctx->stack[ctx->stack_len - 1];
	    t2 = ctx->stack[ctx->stack_len - 2];
	    ctx->stack[ctx->stack_len - 1] = t2;
	    ctx->stack[ctx->stack_len - 2] = t1;
	    goto no_push;
	  }

	case DW_OP_over:
	  result = dwarf_expr_fetch (ctx, 1);
	  in_stack_memory = dwarf_expr_fetch_in_stack_memory (ctx, 1);
	  break;

	case DW_OP_rot:
	  {
	    struct dwarf_stack_value t1, t2, t3;

	    if (ctx->stack_len < 3)
	       error (_("Not enough elements for DW_OP_rot. Need 3, have %d."),
		      ctx->stack_len);
	    t1 = ctx->stack[ctx->stack_len - 1];
	    t2 = ctx->stack[ctx->stack_len - 2];
	    t3 = ctx->stack[ctx->stack_len - 3];
	    ctx->stack[ctx->stack_len - 1] = t2;
	    ctx->stack[ctx->stack_len - 2] = t3;
	    ctx->stack[ctx->stack_len - 3] = t1;
	    goto no_push;
	  }

	case DW_OP_deref:
	case DW_OP_deref_size:
	case DW_OP_abs:
	case DW_OP_neg:
	case DW_OP_not:
	case DW_OP_plus_uconst:
	  /* Unary operations.  */
	  result = dwarf_expr_fetch (ctx, 0);
	  dwarf_expr_pop (ctx);

	  switch (op)
	    {
	    case DW_OP_deref:
	      {
		gdb_byte *buf = alloca (ctx->addr_size);
		(ctx->read_mem) (ctx->baton, buf, result, ctx->addr_size);
		result = dwarf2_read_address (ctx->gdbarch,
					      buf, buf + ctx->addr_size,
					      ctx->addr_size);
	      }
	      break;

	    case DW_OP_deref_size:
	      {
		int addr_size = *op_ptr++;
		gdb_byte *buf = alloca (addr_size);
		(ctx->read_mem) (ctx->baton, buf, result, addr_size);
		result = dwarf2_read_address (ctx->gdbarch,
					      buf, buf + addr_size,
					      addr_size);
	      }
	      break;

	    case DW_OP_abs:
	      if ((signed int) result < 0)
		result = -result;
	      break;
	    case DW_OP_neg:
	      result = -result;
	      break;
	    case DW_OP_not:
	      result = ~result;
	      break;
	    case DW_OP_plus_uconst:
	      op_ptr = read_uleb128 (op_ptr, op_end, &reg);
	      result += reg;
	      break;
	    }
	  break;

	case DW_OP_and:
	case DW_OP_div:
	case DW_OP_minus:
	case DW_OP_mod:
	case DW_OP_mul:
	case DW_OP_or:
	case DW_OP_plus:
	case DW_OP_shl:
	case DW_OP_shr:
	case DW_OP_shra:
	case DW_OP_xor:
	case DW_OP_le:
	case DW_OP_ge:
	case DW_OP_eq:
	case DW_OP_lt:
	case DW_OP_gt:
	case DW_OP_ne:
	  {
	    /* Binary operations.  Use the value engine to do computations in
	       the right width.  */
	    CORE_ADDR first, second;
	    enum exp_opcode binop;
	    struct value *val1 = NULL, *val2 = NULL;
	    struct type *stype, *utype;

	    second = dwarf_expr_fetch (ctx, 0);
	    dwarf_expr_pop (ctx);

	    first = dwarf_expr_fetch (ctx, 0);
	    dwarf_expr_pop (ctx);

	    utype = unsigned_address_type (ctx->gdbarch, ctx->addr_size);
	    stype = signed_address_type (ctx->gdbarch, ctx->addr_size);

	    switch (op)
	      {
	      case DW_OP_and:
		binop = BINOP_BITWISE_AND;
		break;
	      case DW_OP_div:
		binop = BINOP_DIV;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
                break;
	      case DW_OP_minus:
		binop = BINOP_SUB;
		break;
	      case DW_OP_mod:
		binop = BINOP_MOD;
		break;
	      case DW_OP_mul:
		binop = BINOP_MUL;
		break;
	      case DW_OP_or:
		binop = BINOP_BITWISE_IOR;
		break;
	      case DW_OP_plus:
		binop = BINOP_ADD;
		break;
	      case DW_OP_shl:
		binop = BINOP_LSH;
		break;
	      case DW_OP_shr:
		binop = BINOP_RSH;
                break;
	      case DW_OP_shra:
		binop = BINOP_RSH;
		val1 = value_from_longest (stype, first);
		break;
	      case DW_OP_xor:
		binop = BINOP_BITWISE_XOR;
		break;
	      case DW_OP_le:
		binop = BINOP_LEQ;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
		break;
	      case DW_OP_ge:
		binop = BINOP_GEQ;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
		break;
	      case DW_OP_eq:
		binop = BINOP_EQUAL;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
		break;
	      case DW_OP_lt:
		binop = BINOP_LESS;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
		break;
	      case DW_OP_gt:
		binop = BINOP_GTR;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
		break;
	      case DW_OP_ne:
		binop = BINOP_NOTEQUAL;
		val1 = value_from_longest (stype, first);
		val2 = value_from_longest (stype, second);
		break;
	      default:
		internal_error (__FILE__, __LINE__,
				_("Can't be reached."));
	      }

	    /* We use unsigned operands by default.  */
	    if (val1 == NULL)
	      val1 = value_from_longest (utype, first);
	    if (val2 == NULL)
	      val2 = value_from_longest (utype, second);

	    result = value_as_long (value_binop (val1, val2, binop));
	  }
	  break;

	case DW_OP_call_frame_cfa:
	  result = (ctx->get_frame_cfa) (ctx->baton);
	  in_stack_memory = 1;
	  break;

	case DW_OP_GNU_push_tls_address:
	  /* Variable is at a constant offset in the thread-local
	  storage block into the objfile for the current thread and
	  the dynamic linker module containing this expression. Here
	  we return returns the offset from that base.  The top of the
	  stack has the offset from the beginning of the thread
	  control block at which the variable is located.  Nothing
	  should follow this operator, so the top of stack would be
	  returned.  */
	  result = dwarf_expr_fetch (ctx, 0);
	  dwarf_expr_pop (ctx);
	  result = (ctx->get_tls_address) (ctx->baton, result);
	  break;

	case DW_OP_skip:
	  offset = extract_signed_integer (op_ptr, 2, byte_order);
	  op_ptr += 2;
	  op_ptr += offset;
	  goto no_push;

	case DW_OP_bra:
	  offset = extract_signed_integer (op_ptr, 2, byte_order);
	  op_ptr += 2;
	  if (dwarf_expr_fetch (ctx, 0) != 0)
	    op_ptr += offset;
	  dwarf_expr_pop (ctx);
	  goto no_push;

	case DW_OP_nop:
	  goto no_push;

        case DW_OP_piece:
          {
            ULONGEST size;

            /* Record the piece.  */
            op_ptr = read_uleb128 (op_ptr, op_end, &size);
	    add_piece (ctx, size);

            /* Pop off the address/regnum, and reset the location
	       type.  */
	    if (ctx->location != DWARF_VALUE_LITERAL)
	      dwarf_expr_pop (ctx);
            ctx->location = DWARF_VALUE_MEMORY;
          }
          goto no_push;

	case DW_OP_GNU_uninit:
	  if (op_ptr != op_end)
	    error (_("DWARF-2 expression error: DW_OP_GNU_uninit must always "
		   "be the very last op."));

	  ctx->initialized = 0;
	  goto no_push;

	default:
	  error (_("Unhandled dwarf expression opcode 0x%x"), op);
	}

      /* Most things push a result value.  */
      dwarf_expr_push (ctx, result, in_stack_memory);
    no_push:;
    }

  ctx->recursion_depth--;
  gdb_assert (ctx->recursion_depth >= 0);
}
예제 #12
0
void MachObject::readWeakBind(const uint8_t* start, const uint8_t* end)
{
    const uint8_t* pos = start;

    if (gVerboseLog) {
        lnk::log("binding weak symbols\n            start %p, end %p", start, end);
    }

    /* Data retrieved from the opcodes */
    int libraryOrdinal = 0;
    int segmentIndex = 0;
    const char* symbolName = NULL;
    uint8_t symbolFlags = 0;
    intptr_t addend = 0;
    uint8_t type = 0;

    /* XXX: get from segdata */
    uintptr_t segmentEndAddress = 0;
    uintptr_t address = 0;

    uint32_t count;
    uint32_t skip;

    /* Parse opcodes */
    while (pos < end) {
        uint8_t opcode = *(pos) & BIND_OPCODE_MASK;
        uint8_t immediate = *(pos) & BIND_IMMEDIATE_MASK;

        pos++;

        switch (opcode) {
        case BIND_OPCODE_DONE:
        {
            break;
        }
        case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
        {
            libraryOrdinal = immediate;
            break;
        }
        case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
        {
            libraryOrdinal = (int)read_uleb128(pos, end);
            break;
        }
        case BIND_OPCODE_SET_TYPE_IMM:
        {
            type = immediate;
            break;
        }
        case BIND_OPCODE_SET_ADDEND_SLEB:
        {
            addend = read_sleb128(pos, end);
            break;
        }
        case BIND_OPCODE_ADD_ADDR_ULEB:
        {
            address += read_uleb128(pos, end);
            break;
        }
        case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
        {
            segmentIndex = immediate;

            address = segActualLoadAddr(segmentIndex) + read_uleb128(pos, end);
            segmentEndAddress = segActualEndAddr(segmentIndex);
            break;
        }
        case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
        {
            symbolName = (char*)pos;
            symbolFlags = immediate;
            while (*pos != '\0')
                ++pos;
            ++pos;

            break;
        }
        case BIND_OPCODE_DO_BIND:
        {
            if ( address >= segmentEndAddress )
                throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, pos);

            /*
            this->bind(address,
            		   type,
            		   symbolName,
            		   symbolFlags,
            		   addend,
            		   libraryOrdinal,
            		   "weak");
            */

            address += sizeof(intptr_t);
            break;
        }
        case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
        {
            if ( address >= segmentEndAddress )
                throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, pos);

            /*
            this->bind(address,
            		   type,
            		   symbolName,
            		   symbolFlags,
            		   addend,
            		   libraryOrdinal,
            		   "weak");
            */

            address += read_uleb128(pos, end) + sizeof(intptr_t);
            break;
        }
        case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
        {
            if ( address >= segmentEndAddress )
                throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, pos);
            /*
            this->bind(address,
            		   type,
            		   symbolName,
            		   symbolFlags,
            		   addend,
            		   libraryOrdinal,
            		   "weak");
            */

            address += immediate*sizeof(intptr_t) + sizeof(intptr_t);
            break;
        }
        case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
        {
            count = read_uleb128(pos, end);
            skip = read_uleb128(pos, end);
            for (uint32_t i=0; i < count; ++i) {
                if ( address >= segmentEndAddress )
                    throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, pos);
                /*
                this->bind(address,
                		   type,
                		   symbolName,
                		   symbolFlags,
                		   addend,
                		   libraryOrdinal,
                		   "weak");
                */

                address += skip + sizeof(intptr_t);
            }
            break;
        }
        default:
        {
            lnk::halt("invalid opcode %d for bind nl", *pos);
            break;
        }
        }
    }
}
예제 #13
0
void MachObject::readLazyBind(const uint8_t* start, const uint8_t* end)
{
    const uint8_t* pos = start;

    if (gVerboseLog) {
        lnk::log("binding lazy symbols\n            start %p, end %p", start, end);
    }

    /* Data retrieved from the opcodes */
    int libraryOrdinal = 0;
    int segmentIndex = 0;
    const char* symbolName = NULL;
    uint8_t symbolFlags = 0;
    intptr_t addend = 0;
    uint8_t type = BIND_TYPE_POINTER; /* ptr */

    /* XXX: get from segdata */
    uintptr_t segmentEndAddress = 0;
    uintptr_t address = 0;

    /* Parse opcodes */
    while (pos < end) {
        uint8_t opcode = *(pos) & BIND_OPCODE_MASK;
        uint8_t immediate = *(pos) & BIND_IMMEDIATE_MASK;

        pos++;

        switch (opcode) {
        case BIND_OPCODE_DONE:
        {
            break;
        }
        case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
        {
            libraryOrdinal = immediate;
            break;
        }
        case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
        {
            libraryOrdinal = (int)read_uleb128(pos, end);
            break;
        }
        case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
        {
            /* the special ordinals are negative numbers */
            if ( immediate == 0 )
                libraryOrdinal = 0;
            else {
                int8_t signExtended = BIND_OPCODE_MASK | immediate;
                libraryOrdinal = signExtended;
            }
            break;
        }
        case BIND_OPCODE_SET_TYPE_IMM:
        {
            type = immediate;
            break;
        }
        case BIND_OPCODE_SET_ADDEND_SLEB:
        {
            addend = read_sleb128(pos, end);
            break;
        }
        case BIND_OPCODE_ADD_ADDR_ULEB:
        {
            address += read_uleb128(pos, end);
            break;
        }
        case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
        {
            segmentIndex = immediate;

            address = segActualLoadAddr(segmentIndex) + read_uleb128(pos, end);
            segmentEndAddress = segActualEndAddr(segmentIndex);
            break;
        }
        case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
        {
            symbolName = (char*)pos;
            symbolFlags = immediate;
            while (*pos != '\0')
                ++pos;
            ++pos;

            break;
        }
        case BIND_OPCODE_DO_BIND:
        {
            if ( address >= segmentEndAddress )
                throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, pos);

            this->bind(address,
                       type,
                       symbolName,
                       symbolFlags,
                       addend,
                       libraryOrdinal,
                       "lazy");

            address += sizeof(intptr_t);
            break;
        }
        case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
        case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
        case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
        default:
        {
            lnk::halt("invalid opcode %d for bind lazy", *pos);
            break;
        }
        }
    }
}
예제 #14
0
void
_bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
			 asection *sec, struct elf_reloc_cookie *cookie)
{
#define REQUIRE(COND)					\
  do							\
    if (!(COND))					\
      goto free_no_table;				\
  while (0)

  bfd_byte *ehbuf = NULL, *buf, *end;
  bfd_byte *last_fde;
  struct eh_cie_fde *this_inf;
  unsigned int hdr_length, hdr_id;
  unsigned int cie_count;
  struct cie *cie, *local_cies = NULL;
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  struct eh_frame_sec_info *sec_info = NULL;
  unsigned int ptr_size;
  unsigned int num_cies;
  unsigned int num_entries;
  elf_gc_mark_hook_fn gc_mark_hook;

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;
  if (hdr_info->parsed_eh_frames)
    return;

  if (sec->size == 0)
    {
      /* This file does not contain .eh_frame information.  */
      return;
    }

  if (bfd_is_abs_section (sec->output_section))
    {
      /* At least one of the sections is being discarded from the
	 link, so we should just ignore them.  */
      return;
    }

  /* Read the frame unwind information from abfd.  */

  REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf));

  if (sec->size >= 4
      && bfd_get_32 (abfd, ehbuf) == 0
      && cookie->rel == cookie->relend)
    {
      /* Empty .eh_frame section.  */
      free (ehbuf);
      return;
    }

  /* If .eh_frame section size doesn't fit into int, we cannot handle
     it (it would need to use 64-bit .eh_frame format anyway).  */
  REQUIRE (sec->size == (unsigned int) sec->size);

  ptr_size = (get_elf_backend_data (abfd)
	      ->elf_backend_eh_frame_address_size (abfd, sec));
  REQUIRE (ptr_size != 0);

  /* Go through the section contents and work out how many FDEs and
     CIEs there are.  */
  buf = ehbuf;
  end = ehbuf + sec->size;
  num_cies = 0;
  num_entries = 0;
  while (buf != end)
    {
      num_entries++;

      /* Read the length of the entry.  */
      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_length = bfd_get_32 (abfd, buf - 4);

      /* 64-bit .eh_frame is not supported.  */
      REQUIRE (hdr_length != 0xffffffff);
      if (hdr_length == 0)
	break;

      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_id = bfd_get_32 (abfd, buf - 4);
      if (hdr_id == 0)
	num_cies++;

      REQUIRE (skip_bytes (&buf, end, hdr_length - 4));
    }

  sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info)
			  + (num_entries - 1) * sizeof (struct eh_cie_fde));
  REQUIRE (sec_info);

  /* We need to have a "struct cie" for each CIE in this section.  */
  local_cies = bfd_zmalloc (num_cies * sizeof (*local_cies));
  REQUIRE (local_cies);

#define ENSURE_NO_RELOCS(buf)				\
  REQUIRE (!(cookie->rel < cookie->relend		\
	     && (cookie->rel->r_offset			\
		 < (bfd_size_type) ((buf) - ehbuf))	\
	     && cookie->rel->r_info != 0))

#define SKIP_RELOCS(buf)				\
  while (cookie->rel < cookie->relend			\
	 && (cookie->rel->r_offset			\
	     < (bfd_size_type) ((buf) - ehbuf)))	\
    cookie->rel++

#define GET_RELOC(buf)					\
  ((cookie->rel < cookie->relend			\
    && (cookie->rel->r_offset				\
	== (bfd_size_type) ((buf) - ehbuf)))		\
   ? cookie->rel : NULL)

  buf = ehbuf;
  cie_count = 0;
  gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
  while ((bfd_size_type) (buf - ehbuf) != sec->size)
    {
      char *aug;
      bfd_byte *start, *insns, *insns_end;
      bfd_size_type length;
      unsigned int set_loc_count;

      this_inf = sec_info->entry + sec_info->count;
      last_fde = buf;

      /* Read the length of the entry.  */
      REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4));
      hdr_length = bfd_get_32 (abfd, buf - 4);

      /* The CIE/FDE must be fully contained in this input section.  */
      REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size);
      end = buf + hdr_length;

      this_inf->offset = last_fde - ehbuf;
      this_inf->size = 4 + hdr_length;
      this_inf->reloc_index = cookie->rel - cookie->rels;

      if (hdr_length == 0)
	{
	  /* A zero-length CIE should only be found at the end of
	     the section.  */
	  REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size);
	  ENSURE_NO_RELOCS (buf);
	  sec_info->count++;
	  break;
	}

      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_id = bfd_get_32 (abfd, buf - 4);

      if (hdr_id == 0)
	{
	  unsigned int initial_insn_length;

	  /* CIE  */
	  this_inf->cie = 1;

	  /* Point CIE to one of the section-local cie structures.  */
	  cie = local_cies + cie_count++;

	  cie->cie_inf = this_inf;
	  cie->length = hdr_length;
	  cie->output_sec = sec->output_section;
	  start = buf;
	  REQUIRE (read_byte (&buf, end, &cie->version));

	  /* Cannot handle unknown versions.  */
	  REQUIRE (cie->version == 1 || cie->version == 3);
	  REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation));

	  strcpy (cie->augmentation, (char *) buf);
	  buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1;
	  ENSURE_NO_RELOCS (buf);
	  if (buf[0] == 'e' && buf[1] == 'h')
	    {
	      /* GCC < 3.0 .eh_frame CIE */
	      /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__
		 is private to each CIE, so we don't need it for anything.
		 Just skip it.  */
	      REQUIRE (skip_bytes (&buf, end, ptr_size));
	      SKIP_RELOCS (buf);
	    }
	  REQUIRE (read_uleb128 (&buf, end, &cie->code_align));
	  REQUIRE (read_sleb128 (&buf, end, &cie->data_align));
	  if (cie->version == 1)
	    {
	      REQUIRE (buf < end);
	      cie->ra_column = *buf++;
	    }
	  else
	    REQUIRE (read_uleb128 (&buf, end, &cie->ra_column));
	  ENSURE_NO_RELOCS (buf);
	  cie->lsda_encoding = DW_EH_PE_omit;
	  cie->fde_encoding = DW_EH_PE_omit;
	  cie->per_encoding = DW_EH_PE_omit;
	  aug = cie->augmentation;
	  if (aug[0] != 'e' || aug[1] != 'h')
	    {
	      if (*aug == 'z')
		{
		  aug++;
		  REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size));
	  	  ENSURE_NO_RELOCS (buf);
		}

	      while (*aug != '\0')
		switch (*aug++)
		  {
		  case 'L':
		    REQUIRE (read_byte (&buf, end, &cie->lsda_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size));
		    break;
		  case 'R':
		    REQUIRE (read_byte (&buf, end, &cie->fde_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size));
		    break;
		  case 'S':
		    break;
		  case 'P':
		    {
		      int per_width;

		      REQUIRE (read_byte (&buf, end, &cie->per_encoding));
		      per_width = get_DW_EH_PE_width (cie->per_encoding,
						      ptr_size);
		      REQUIRE (per_width);
		      if ((cie->per_encoding & 0xf0) == DW_EH_PE_aligned)
			{
			  length = -(buf - ehbuf) & (per_width - 1);
			  REQUIRE (skip_bytes (&buf, end, length));
			}
		      ENSURE_NO_RELOCS (buf);
		      /* Ensure we have a reloc here.  */
		      REQUIRE (GET_RELOC (buf));
		      cie->personality.reloc_index
			= cookie->rel - cookie->rels;
		      /* Cope with MIPS-style composite relocations.  */
		      do
			cookie->rel++;
		      while (GET_RELOC (buf) != NULL);
		      REQUIRE (skip_bytes (&buf, end, per_width));
		    }
		    break;
		  default:
		    /* Unrecognized augmentation. Better bail out.  */
		    goto free_no_table;
		  }
	    }

	  /* For shared libraries, try to get rid of as many RELATIVE relocs
	     as possible.  */
	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_relative_eh_frame
		  (abfd, info, sec)))
	    {
	      if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr)
		this_inf->make_relative = 1;
	      /* If the CIE doesn't already have an 'R' entry, it's fairly
		 easy to add one, provided that there's no aligned data
		 after the augmentation string.  */
	      else if (cie->fde_encoding == DW_EH_PE_omit
		       && (cie->per_encoding & 0xf0) != DW_EH_PE_aligned)
		{
		  if (*cie->augmentation == 0)
		    this_inf->add_augmentation_size = 1;
		  this_inf->u.cie.add_fde_encoding = 1;
		  this_inf->make_relative = 1;
		}
	    }

	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_lsda_relative_eh_frame
		  (abfd, info, sec))
	      && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr)
	    cie->can_make_lsda_relative = 1;

	  /* If FDE encoding was not specified, it defaults to
	     DW_EH_absptr.  */
	  if (cie->fde_encoding == DW_EH_PE_omit)
	    cie->fde_encoding = DW_EH_PE_absptr;

	  initial_insn_length = end - buf;
	  if (initial_insn_length <= sizeof (cie->initial_instructions))
	    {
	      cie->initial_insn_length = initial_insn_length;
	      memcpy (cie->initial_instructions, buf, initial_insn_length);
	    }
	  insns = buf;
	  buf += initial_insn_length;
	  ENSURE_NO_RELOCS (buf);

	  if (hdr_info->merge_cies)
	    this_inf->u.cie.u.full_cie = cie;
	  this_inf->u.cie.per_encoding_relative
	    = (cie->per_encoding & 0x70) == DW_EH_PE_pcrel;
	}
      else
	{
	  asection *rsec;

	  /* Find the corresponding CIE.  */
	  unsigned int cie_offset = this_inf->offset + 4 - hdr_id;
	  for (cie = local_cies; cie < local_cies + cie_count; cie++)
	    if (cie_offset == cie->cie_inf->offset)
	      break;

	  /* Ensure this FDE references one of the CIEs in this input
	     section.  */
	  REQUIRE (cie != local_cies + cie_count);
	  this_inf->u.fde.cie_inf = cie->cie_inf;
	  this_inf->make_relative = cie->cie_inf->make_relative;
	  this_inf->add_augmentation_size
	    = cie->cie_inf->add_augmentation_size;

	  ENSURE_NO_RELOCS (buf);
	  REQUIRE (GET_RELOC (buf));

	  /* Chain together the FDEs for each section.  */
	  rsec = _bfd_elf_gc_mark_rsec (info, sec, gc_mark_hook, cookie);
	  /* RSEC will be NULL if FDE was cleared out as it was belonging to
	     a discarded SHT_GROUP.  */
	  if (rsec)
	    {
	      REQUIRE (rsec->owner == abfd);
	      this_inf->u.fde.next_for_section = elf_fde_list (rsec);
	      elf_fde_list (rsec) = this_inf;
	    }

	  /* Skip the initial location and address range.  */
	  start = buf;
	  length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
	  REQUIRE (skip_bytes (&buf, end, 2 * length));

	  /* Skip the augmentation size, if present.  */
	  if (cie->augmentation[0] == 'z')
	    REQUIRE (read_uleb128 (&buf, end, &length));
	  else
	    length = 0;

	  /* Of the supported augmentation characters above, only 'L'
	     adds augmentation data to the FDE.  This code would need to
	     be adjusted if any future augmentations do the same thing.  */
	  if (cie->lsda_encoding != DW_EH_PE_omit)
	    {
	      SKIP_RELOCS (buf);
	      if (cie->can_make_lsda_relative && GET_RELOC (buf))
		cie->cie_inf->u.cie.make_lsda_relative = 1;
	      this_inf->lsda_offset = buf - start;
	      /* If there's no 'z' augmentation, we don't know where the
		 CFA insns begin.  Assume no padding.  */
	      if (cie->augmentation[0] != 'z')
		length = end - buf;
	    }

	  /* Skip over the augmentation data.  */
	  REQUIRE (skip_bytes (&buf, end, length));
	  insns = buf;

	  buf = last_fde + 4 + hdr_length;

	  /* For NULL RSEC (cleared FDE belonging to a discarded section)
	     the relocations are commonly cleared.  We do not sanity check if
	     all these relocations are cleared as (1) relocations to
	     .gcc_except_table will remain uncleared (they will get dropped
	     with the drop of this unused FDE) and (2) BFD already safely drops
	     relocations of any type to .eh_frame by
	     elf_section_ignore_discarded_relocs.
	     TODO: The .gcc_except_table entries should be also filtered as
	     .eh_frame entries; or GCC could rather use COMDAT for them.  */
	  SKIP_RELOCS (buf);
	}

      /* Try to interpret the CFA instructions and find the first
	 padding nop.  Shrink this_inf's size so that it doesn't
	 include the padding.  */
      length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
      set_loc_count = 0;
      insns_end = skip_non_nops (insns, end, length, &set_loc_count);
      /* If we don't understand the CFA instructions, we can't know
	 what needs to be adjusted there.  */
      if (insns_end == NULL
	  /* For the time being we don't support DW_CFA_set_loc in
	     CIE instructions.  */
	  || (set_loc_count && this_inf->cie))
	goto free_no_table;
      this_inf->size -= end - insns_end;
      if (insns_end != end && this_inf->cie)
	{
	  cie->initial_insn_length -= end - insns_end;
	  cie->length -= end - insns_end;
	}
      if (set_loc_count
	  && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel
	      || this_inf->make_relative))
	{
	  unsigned int cnt;
	  bfd_byte *p;

	  this_inf->set_loc = bfd_malloc ((set_loc_count + 1)
					  * sizeof (unsigned int));
	  REQUIRE (this_inf->set_loc);
	  this_inf->set_loc[0] = set_loc_count;
	  p = insns;
	  cnt = 0;
	  while (p < end)
	    {
	      if (*p == DW_CFA_set_loc)
		this_inf->set_loc[++cnt] = p + 1 - start;
	      REQUIRE (skip_cfa_op (&p, end, length));
	    }
	}

      this_inf->removed = 1;
      this_inf->fde_encoding = cie->fde_encoding;
      this_inf->lsda_encoding = cie->lsda_encoding;
      sec_info->count++;
    }
  BFD_ASSERT (sec_info->count == num_entries);
  BFD_ASSERT (cie_count == num_cies);

  elf_section_data (sec)->sec_info = sec_info;
  sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME;
  if (hdr_info->merge_cies)
    {
      sec_info->cies = local_cies;
      local_cies = NULL;
    }
  goto success;

 free_no_table:
  (*info->callbacks->einfo)
    (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"),
     abfd, sec);
  hdr_info->table = FALSE;
  if (sec_info)
    free (sec_info);
 success:
  if (ehbuf)
    free (ehbuf);
  if (local_cies)
    free (local_cies);
#undef REQUIRE
}
예제 #15
0
bfd_boolean
_bfd_elf_discard_section_eh_frame
   (bfd *abfd, struct bfd_link_info *info, asection *sec,
    bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
    struct elf_reloc_cookie *cookie)
{
#define REQUIRE(COND)					\
  do							\
    if (!(COND))					\
      goto free_no_table;				\
  while (0)

  bfd_byte *ehbuf = NULL, *buf;
  bfd_byte *last_fde;
  struct eh_cie_fde *ent, *this_inf;
  unsigned int hdr_length, hdr_id;
  struct extended_cie
    {
      struct cie cie;
      unsigned int offset;
      unsigned int usage_count;
      unsigned int entry;
    } *ecies = NULL, *ecie;
  unsigned int ecie_count = 0, ecie_alloced = 0;
  struct cie *cie;
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  struct eh_frame_sec_info *sec_info = NULL;
  unsigned int offset;
  unsigned int ptr_size;
  unsigned int entry_alloced;

  if (sec->size == 0)
    {
      /* This file does not contain .eh_frame information.  */
      return FALSE;
    }

  if (bfd_is_abs_section (sec->output_section))
    {
      /* At least one of the sections is being discarded from the
	 link, so we should just ignore them.  */
      return FALSE;
    }

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  if (hdr_info->cies == NULL && !info->relocatable)
    hdr_info->cies = htab_try_create (1, cie_hash, cie_eq, free);

  /* Read the frame unwind information from abfd.  */

  REQUIRE (bfd_malloc_and_get_section (abfd, sec, &ehbuf));

  if (sec->size >= 4
      && bfd_get_32 (abfd, ehbuf) == 0
      && cookie->rel == cookie->relend)
    {
      /* Empty .eh_frame section.  */
      free (ehbuf);
      return FALSE;
    }

  /* If .eh_frame section size doesn't fit into int, we cannot handle
     it (it would need to use 64-bit .eh_frame format anyway).  */
  REQUIRE (sec->size == (unsigned int) sec->size);

  ptr_size = (get_elf_backend_data (abfd)
	      ->elf_backend_eh_frame_address_size (abfd, sec));
  REQUIRE (ptr_size != 0);

  buf = ehbuf;
  sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info)
			  + 99 * sizeof (struct eh_cie_fde));
  REQUIRE (sec_info);

  entry_alloced = 100;

#define ENSURE_NO_RELOCS(buf)				\
  REQUIRE (!(cookie->rel < cookie->relend		\
	     && (cookie->rel->r_offset			\
		 < (bfd_size_type) ((buf) - ehbuf))	\
	     && cookie->rel->r_info != 0))

#define SKIP_RELOCS(buf)				\
  while (cookie->rel < cookie->relend			\
	 && (cookie->rel->r_offset			\
	     < (bfd_size_type) ((buf) - ehbuf)))	\
    cookie->rel++

#define GET_RELOC(buf)					\
  ((cookie->rel < cookie->relend			\
    && (cookie->rel->r_offset				\
	== (bfd_size_type) ((buf) - ehbuf)))		\
   ? cookie->rel : NULL)

  for (;;)
    {
      char *aug;
      bfd_byte *start, *end, *insns, *insns_end;
      bfd_size_type length;
      unsigned int set_loc_count;

      if (sec_info->count == entry_alloced)
	{
	  sec_info = bfd_realloc (sec_info,
				  sizeof (struct eh_frame_sec_info)
				  + ((entry_alloced + 99)
				     * sizeof (struct eh_cie_fde)));
	  REQUIRE (sec_info);

	  memset (&sec_info->entry[entry_alloced], 0,
		  100 * sizeof (struct eh_cie_fde));
	  entry_alloced += 100;
	}

      this_inf = sec_info->entry + sec_info->count;
      last_fde = buf;

      if ((bfd_size_type) (buf - ehbuf) == sec->size)
	break;

      /* Read the length of the entry.  */
      REQUIRE (skip_bytes (&buf, ehbuf + sec->size, 4));
      hdr_length = bfd_get_32 (abfd, buf - 4);

      /* 64-bit .eh_frame is not supported.  */
      REQUIRE (hdr_length != 0xffffffff);

      /* The CIE/FDE must be fully contained in this input section.  */
      REQUIRE ((bfd_size_type) (buf - ehbuf) + hdr_length <= sec->size);
      end = buf + hdr_length;

      this_inf->offset = last_fde - ehbuf;
      this_inf->size = 4 + hdr_length;

      if (hdr_length == 0)
	{
	  /* A zero-length CIE should only be found at the end of
	     the section.  */
	  REQUIRE ((bfd_size_type) (buf - ehbuf) == sec->size);
	  ENSURE_NO_RELOCS (buf);
	  sec_info->count++;
	  break;
	}

      REQUIRE (skip_bytes (&buf, end, 4));
      hdr_id = bfd_get_32 (abfd, buf - 4);

      if (hdr_id == 0)
	{
	  unsigned int initial_insn_length;

	  /* CIE  */
	  this_inf->cie = 1;

	  if (ecie_count == ecie_alloced)
	    {
	      ecies = bfd_realloc (ecies,
				   (ecie_alloced + 20) * sizeof (*ecies));
	      REQUIRE (ecies);
	      memset (&ecies[ecie_alloced], 0, 20 * sizeof (*ecies));
	      ecie_alloced += 20;
	    }

	  cie = &ecies[ecie_count].cie;
	  ecies[ecie_count].offset = this_inf->offset;
	  ecies[ecie_count++].entry = sec_info->count;
	  cie->length = hdr_length;
	  start = buf;
	  REQUIRE (read_byte (&buf, end, &cie->version));

	  /* Cannot handle unknown versions.  */
	  REQUIRE (cie->version == 1 || cie->version == 3);
	  REQUIRE (strlen ((char *) buf) < sizeof (cie->augmentation));

	  strcpy (cie->augmentation, (char *) buf);
	  buf = (bfd_byte *) strchr ((char *) buf, '\0') + 1;
	  ENSURE_NO_RELOCS (buf);
	  if (buf[0] == 'e' && buf[1] == 'h')
	    {
	      /* GCC < 3.0 .eh_frame CIE */
	      /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__
		 is private to each CIE, so we don't need it for anything.
		 Just skip it.  */
	      REQUIRE (skip_bytes (&buf, end, ptr_size));
	      SKIP_RELOCS (buf);
	    }
	  REQUIRE (read_uleb128 (&buf, end, &cie->code_align));
	  REQUIRE (read_sleb128 (&buf, end, &cie->data_align));
	  if (cie->version == 1)
	    {
	      REQUIRE (buf < end);
	      cie->ra_column = *buf++;
	    }
	  else
	    REQUIRE (read_uleb128 (&buf, end, &cie->ra_column));
	  ENSURE_NO_RELOCS (buf);
	  cie->lsda_encoding = DW_EH_PE_omit;
	  cie->fde_encoding = DW_EH_PE_omit;
	  cie->per_encoding = DW_EH_PE_omit;
	  aug = cie->augmentation;
	  if (aug[0] != 'e' || aug[1] != 'h')
	    {
	      if (*aug == 'z')
		{
		  aug++;
		  REQUIRE (read_uleb128 (&buf, end, &cie->augmentation_size));
	  	  ENSURE_NO_RELOCS (buf);
		}

	      while (*aug != '\0')
		switch (*aug++)
		  {
		  case 'L':
		    REQUIRE (read_byte (&buf, end, &cie->lsda_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie->lsda_encoding, ptr_size));
		    break;
		  case 'R':
		    REQUIRE (read_byte (&buf, end, &cie->fde_encoding));
		    ENSURE_NO_RELOCS (buf);
		    REQUIRE (get_DW_EH_PE_width (cie->fde_encoding, ptr_size));
		    break;
		  case 'S':
		    break;
		  case 'P':
		    {
		      int per_width;

		      REQUIRE (read_byte (&buf, end, &cie->per_encoding));
		      per_width = get_DW_EH_PE_width (cie->per_encoding,
						      ptr_size);
		      REQUIRE (per_width);
		      if ((cie->per_encoding & 0xf0) == DW_EH_PE_aligned)
			{
			  length = -(buf - ehbuf) & (per_width - 1);
			  REQUIRE (skip_bytes (&buf, end, length));
			}
		      ENSURE_NO_RELOCS (buf);
		      /* Ensure we have a reloc here.  */
		      if (GET_RELOC (buf) != NULL)
			{
			  unsigned long r_symndx;

#ifdef BFD64
			  if (ptr_size == 8)
			    r_symndx = ELF64_R_SYM (cookie->rel->r_info);
			  else
#endif
			    r_symndx = ELF32_R_SYM (cookie->rel->r_info);
			  if (r_symndx >= cookie->locsymcount
			      || ELF_ST_BIND (cookie->locsyms[r_symndx]
					      .st_info) != STB_LOCAL)
			    {
			      struct elf_link_hash_entry *h;

			      r_symndx -= cookie->extsymoff;
			      h = cookie->sym_hashes[r_symndx];

			      while (h->root.type == bfd_link_hash_indirect
				     || h->root.type == bfd_link_hash_warning)
				h = (struct elf_link_hash_entry *)
				    h->root.u.i.link;

			      cie->personality.h = h;
			    }
			  else
			    {
			      Elf_Internal_Sym *sym;
			      asection *sym_sec;
			      bfd_vma val;

			      sym = &cookie->locsyms[r_symndx];
			      sym_sec = (bfd_section_from_elf_index
					 (abfd, sym->st_shndx));
			      if (sym_sec != NULL)
				{
				  if (sym_sec->kept_section != NULL)
				    sym_sec = sym_sec->kept_section;
				  if (sym_sec->output_section != NULL)
				    {
				      val = (sym->st_value
					     + sym_sec->output_offset
					     + sym_sec->output_section->vma);
				      cie->personality.val = val;
				      cie->local_personality = 1;
				    }
				}
			    }

			  /* Cope with MIPS-style composite relocations.  */
			  do
			    cookie->rel++;
			  while (GET_RELOC (buf) != NULL);
			}
		      REQUIRE (skip_bytes (&buf, end, per_width));
		      REQUIRE (cie->local_personality || cie->personality.h);
		    }
		    break;
		  default:
		    /* Unrecognized augmentation. Better bail out.  */
		    goto free_no_table;
		  }
	    }

	  /* For shared libraries, try to get rid of as many RELATIVE relocs
	     as possible.  */
	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_relative_eh_frame
		  (abfd, info, sec)))
	    {
	      if ((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr)
		cie->make_relative = 1;
	      /* If the CIE doesn't already have an 'R' entry, it's fairly
		 easy to add one, provided that there's no aligned data
		 after the augmentation string.  */
	      else if (cie->fde_encoding == DW_EH_PE_omit
		       && (cie->per_encoding & 0xf0) != DW_EH_PE_aligned)
		{
		  if (*cie->augmentation == 0)
		    this_inf->add_augmentation_size = 1;
		  this_inf->add_fde_encoding = 1;
		  cie->make_relative = 1;
		}
	    }

	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_lsda_relative_eh_frame
		  (abfd, info, sec))
	      && (cie->lsda_encoding & 0xf0) == DW_EH_PE_absptr)
	    cie->make_lsda_relative = 1;

	  /* If FDE encoding was not specified, it defaults to
	     DW_EH_absptr.  */
	  if (cie->fde_encoding == DW_EH_PE_omit)
	    cie->fde_encoding = DW_EH_PE_absptr;

	  initial_insn_length = end - buf;
	  if (initial_insn_length <= sizeof (cie->initial_instructions))
	    {
	      cie->initial_insn_length = initial_insn_length;
	      memcpy (cie->initial_instructions, buf, initial_insn_length);
	    }
	  insns = buf;
	  buf += initial_insn_length;
	  ENSURE_NO_RELOCS (buf);
	}
      else
	{
	  /* Find the corresponding CIE.  */
	  unsigned int cie_offset = this_inf->offset + 4 - hdr_id;
	  for (ecie = ecies; ecie < ecies + ecie_count; ++ecie)
	    if (cie_offset == ecie->offset)
	      break;

	  /* Ensure this FDE references one of the CIEs in this input
	     section.  */
	  REQUIRE (ecie != ecies + ecie_count);
	  cie = &ecie->cie;

	  ENSURE_NO_RELOCS (buf);
	  REQUIRE (GET_RELOC (buf));

	  if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie))
	    /* This is a FDE against a discarded section.  It should
	       be deleted.  */
	    this_inf->removed = 1;
	  else
	    {
	      if (info->shared
		  && (((cie->fde_encoding & 0xf0) == DW_EH_PE_absptr
		       && cie->make_relative == 0)
		      || (cie->fde_encoding & 0xf0) == DW_EH_PE_aligned))
		{
		  /* If a shared library uses absolute pointers
		     which we cannot turn into PC relative,
		     don't create the binary search table,
		     since it is affected by runtime relocations.  */
		  hdr_info->table = FALSE;
		  (*info->callbacks->einfo)
		    (_("%P: fde encoding in %B(%A) prevents .eh_frame_hdr"
		       " table being created.\n"), abfd, sec);
		}
	      ecie->usage_count++;
	      hdr_info->fde_count++;
	      this_inf->cie_inf = (void *) (ecie - ecies);
	    }

	  /* Skip the initial location and address range.  */
	  start = buf;
	  length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
	  REQUIRE (skip_bytes (&buf, end, 2 * length));

	  /* Skip the augmentation size, if present.  */
	  if (cie->augmentation[0] == 'z')
	    REQUIRE (read_uleb128 (&buf, end, &length));
	  else
	    length = 0;

	  /* Of the supported augmentation characters above, only 'L'
	     adds augmentation data to the FDE.  This code would need to
	     be adjusted if any future augmentations do the same thing.  */
	  if (cie->lsda_encoding != DW_EH_PE_omit)
	    {
	      this_inf->lsda_offset = buf - start;
	      /* If there's no 'z' augmentation, we don't know where the
		 CFA insns begin.  Assume no padding.  */
	      if (cie->augmentation[0] != 'z')
		length = end - buf;
	    }

	  /* Skip over the augmentation data.  */
	  REQUIRE (skip_bytes (&buf, end, length));
	  insns = buf;

	  buf = last_fde + 4 + hdr_length;
	  SKIP_RELOCS (buf);
	}

      /* Try to interpret the CFA instructions and find the first
	 padding nop.  Shrink this_inf's size so that it doesn't
	 include the padding.  */
      length = get_DW_EH_PE_width (cie->fde_encoding, ptr_size);
      set_loc_count = 0;
      insns_end = skip_non_nops (insns, end, length, &set_loc_count);
      /* If we don't understand the CFA instructions, we can't know
	 what needs to be adjusted there.  */
      if (insns_end == NULL
	  /* For the time being we don't support DW_CFA_set_loc in
	     CIE instructions.  */
	  || (set_loc_count && this_inf->cie))
	goto free_no_table;
      this_inf->size -= end - insns_end;
      if (insns_end != end && this_inf->cie)
	{
	  cie->initial_insn_length -= end - insns_end;
	  cie->length -= end - insns_end;
	}
      if (set_loc_count
	  && ((cie->fde_encoding & 0xf0) == DW_EH_PE_pcrel
	      || cie->make_relative))
	{
	  unsigned int cnt;
	  bfd_byte *p;

	  this_inf->set_loc = bfd_malloc ((set_loc_count + 1)
					  * sizeof (unsigned int));
	  REQUIRE (this_inf->set_loc);
	  this_inf->set_loc[0] = set_loc_count;
	  p = insns;
	  cnt = 0;
	  while (p < end)
	    {
	      if (*p == DW_CFA_set_loc)
		this_inf->set_loc[++cnt] = p + 1 - start;
	      REQUIRE (skip_cfa_op (&p, end, length));
	    }
	}

      this_inf->fde_encoding = cie->fde_encoding;
      this_inf->lsda_encoding = cie->lsda_encoding;
      sec_info->count++;
    }

  elf_section_data (sec)->sec_info = sec_info;
  sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME;

  /* Look at all CIEs in this section and determine which can be
     removed as unused, which can be merged with previous duplicate
     CIEs and which need to be kept.  */
  for (ecie = ecies; ecie < ecies + ecie_count; ++ecie)
    {
      if (ecie->usage_count == 0)
	{
	  sec_info->entry[ecie->entry].removed = 1;
	  continue;
	}
      ecie->cie.output_sec = sec->output_section;
      ecie->cie.cie_inf = sec_info->entry + ecie->entry;
      cie_compute_hash (&ecie->cie);
      if (hdr_info->cies != NULL)
	{
	  void **loc = htab_find_slot_with_hash (hdr_info->cies, &ecie->cie,
						 ecie->cie.hash, INSERT);
	  if (loc != NULL)
	    {
	      if (*loc != HTAB_EMPTY_ENTRY)
		{
		  sec_info->entry[ecie->entry].removed = 1;
		  ecie->cie.cie_inf = ((struct cie *) *loc)->cie_inf;
		  continue;
		}

	      *loc = malloc (sizeof (struct cie));
	      if (*loc == NULL)
		*loc = HTAB_DELETED_ENTRY;
	      else
		memcpy (*loc, &ecie->cie, sizeof (struct cie));
	    }
	}
      ecie->cie.cie_inf->make_relative = ecie->cie.make_relative;
      ecie->cie.cie_inf->make_lsda_relative = ecie->cie.make_lsda_relative;
      ecie->cie.cie_inf->per_encoding_relative
	= (ecie->cie.per_encoding & 0x70) == DW_EH_PE_pcrel;
    }

  /* Ok, now we can assign new offsets.  */
  offset = 0;
  for (ent = sec_info->entry; ent < sec_info->entry + sec_info->count; ++ent)
    if (!ent->removed)
      {
	if (!ent->cie)
	  {
	    ecie = ecies + (bfd_hostptr_t) ent->cie_inf;
	    ent->cie_inf = ecie->cie.cie_inf;
	  }
	ent->new_offset = offset;
	offset += size_of_output_cie_fde (ent, ptr_size);
      }

  /* Resize the sec as needed.  */
  sec->rawsize = sec->size;
  sec->size = offset;

  free (ehbuf);
  if (ecies)
    free (ecies);
  return offset != sec->rawsize;

free_no_table:
  (*info->callbacks->einfo)
    (_("%P: error in %B(%A); no .eh_frame_hdr table will be created.\n"),
     abfd, sec);
  if (ehbuf)
    free (ehbuf);
  if (sec_info)
    free (sec_info);
  if (ecies)
    free (ecies);
  hdr_info->table = FALSE;
  return FALSE;

#undef REQUIRE
}
static void
execute_cfa_program (unsigned char *insn_ptr, unsigned char *insn_end,
		     struct frame_info *next_frame,
		     struct dwarf2_frame_state *fs)
{
  CORE_ADDR pc = frame_pc_unwind (next_frame);
  int bytes_read;

  while (insn_ptr < insn_end && fs->pc <= pc)
    {
      unsigned char insn = *insn_ptr++;
      ULONGEST utmp, reg;
      LONGEST offset;

      if ((insn & 0xc0) == DW_CFA_advance_loc)
	fs->pc += (insn & 0x3f) * fs->code_align;
      else if ((insn & 0xc0) == DW_CFA_offset)
	{
	  reg = insn & 0x3f;
	  insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
	  offset = utmp * fs->data_align;
	  dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	  fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
	  fs->regs.reg[reg].loc.offset = offset;
	}
      else if ((insn & 0xc0) == DW_CFA_restore)
	{
	  gdb_assert (fs->initial.reg);
	  reg = insn & 0x3f;
	  dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	  fs->regs.reg[reg] = fs->initial.reg[reg];
	}
      else
	{
	  switch (insn)
	    {
	    case DW_CFA_set_loc:
	      fs->pc = dwarf2_read_address (insn_ptr, insn_end, &bytes_read);
	      insn_ptr += bytes_read;
	      break;

	    case DW_CFA_advance_loc1:
	      utmp = extract_unsigned_integer (insn_ptr, 1);
	      fs->pc += utmp * fs->code_align;
	      insn_ptr++;
	      break;
	    case DW_CFA_advance_loc2:
	      utmp = extract_unsigned_integer (insn_ptr, 2);
	      fs->pc += utmp * fs->code_align;
	      insn_ptr += 2;
	      break;
	    case DW_CFA_advance_loc4:
	      utmp = extract_unsigned_integer (insn_ptr, 4);
	      fs->pc += utmp * fs->code_align;
	      insn_ptr += 4;
	      break;

	    case DW_CFA_offset_extended:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
	      offset = utmp * fs->data_align;
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
	      fs->regs.reg[reg].loc.offset = offset;
	      break;

	    case DW_CFA_restore_extended:
	      gdb_assert (fs->initial.reg);
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      fs->regs.reg[reg] = fs->initial.reg[reg];
	      break;

	    case DW_CFA_undefined:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED;
	      break;

	    case DW_CFA_same_value:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE;
	      break;

	    case DW_CFA_register:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
	      fs->regs.reg[reg].loc.reg = utmp;
	      break;

	    case DW_CFA_remember_state:
	      {
		struct dwarf2_frame_state_reg_info *new_rs;

		new_rs = XMALLOC (struct dwarf2_frame_state_reg_info);
		*new_rs = fs->regs;
		fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs);
		fs->regs.prev = new_rs;
	      }
	      break;

	    case DW_CFA_restore_state:
	      {
		struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev;

		gdb_assert (old_rs);

		xfree (fs->regs.reg);
		fs->regs = *old_rs;
		xfree (old_rs);
	      }
	      break;

	    case DW_CFA_def_cfa:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
	      fs->cfa_offset = utmp;
	      fs->cfa_how = CFA_REG_OFFSET;
	      break;

	    case DW_CFA_def_cfa_register:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
	      fs->cfa_how = CFA_REG_OFFSET;
	      break;

	    case DW_CFA_def_cfa_offset:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_offset);
	      /* cfa_how deliberately not set.  */
	      break;

	    case DW_CFA_nop:
	      break;

	    case DW_CFA_def_cfa_expression:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_exp_len);
	      fs->cfa_exp = insn_ptr;
	      fs->cfa_how = CFA_EXP;
	      insn_ptr += fs->cfa_exp_len;
	      break;

	    case DW_CFA_expression:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
	      fs->regs.reg[reg].loc.exp = insn_ptr;
	      fs->regs.reg[reg].exp_len = utmp;
	      fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP;
	      insn_ptr += utmp;
	      break;

	    case DW_CFA_offset_extended_sf:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &reg);
	      insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
	      offset += fs->data_align;
	      dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
	      fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
	      fs->regs.reg[reg].loc.offset = offset;
	      break;

	    case DW_CFA_def_cfa_sf:
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
	      insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
	      fs->cfa_offset = offset * fs->data_align;
	      fs->cfa_how = CFA_REG_OFFSET;
	      break;

	    case DW_CFA_def_cfa_offset_sf:
	      insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
	      fs->cfa_offset = offset * fs->data_align;
	      /* cfa_how deliberately not set.  */
	      break;

	    case DW_CFA_GNU_args_size:
	      /* Ignored.  */
	      insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
	      break;

	    default:
	      internal_error (__FILE__, __LINE__, "Unknown CFI encountered.");
	    }
	}
    }

  /* Don't allow remember/restore between CIE and FDE programs.  */
  dwarf2_frame_state_free_regs (fs->regs.prev);
  fs->regs.prev = NULL;
}
예제 #17
0
파일: personality.c 프로젝트: djc/runa
static const unsigned char *
read_encoded_value_with_base(unsigned char encoding, _Unwind_Ptr base,
                             const unsigned char *p, _Unwind_Ptr *val) {

  union unaligned {
    void *ptr;
    unsigned u2 __attribute__ ((mode (HI)));
    unsigned u4 __attribute__ ((mode (SI)));
    unsigned u8 __attribute__ ((mode (DI)));
    signed s2 __attribute__ ((mode (HI)));
    signed s4 __attribute__ ((mode (SI)));
    signed s8 __attribute__ ((mode (DI)));
  } __attribute__((__packed__));

  const union unaligned *u = (const union unaligned *) p;
  _Unwind_Internal_Ptr result;

  if (encoding == DW_EH_PE_aligned) {
    _Unwind_Internal_Ptr a = (_Unwind_Internal_Ptr) p;
    a = (a + sizeof (void *) - 1) & - sizeof(void *);
    result = *(_Unwind_Internal_Ptr *) a;
    p = (const unsigned char *) (_Unwind_Internal_Ptr) (a + sizeof (void *));
  } else {

    switch (encoding & 0x0f) {

      case DW_EH_PE_absptr:
        result = (_Unwind_Internal_Ptr) u->ptr;
        p += sizeof (void *);
        break;

      case DW_EH_PE_uleb128: {
          _uleb128_t tmp;
          p = read_uleb128(p, &tmp);
          result = (_Unwind_Internal_Ptr) tmp;
        }
        break;

      case DW_EH_PE_sleb128: {
          _sleb128_t tmp;
          p = read_sleb128 (p, &tmp);
          result = (_Unwind_Internal_Ptr) tmp;
        }
        break;

      case DW_EH_PE_udata2:
        result = u->u2;
        p += 2;
        break;
      case DW_EH_PE_udata4:
        result = u->u4;
        p += 4;
        break;
      case DW_EH_PE_udata8:
        result = u->u8;
        p += 8;
        break;

      case DW_EH_PE_sdata2:
        result = u->s2;
        p += 2;
        break;
      case DW_EH_PE_sdata4:
        result = u->s4;
        p += 4;
        break;
      case DW_EH_PE_sdata8:
        result = u->s8;
        p += 8;
        break;

      default:
        abort();

    }

    if (result != 0) {
      result += ((encoding & 0x70) == DW_EH_PE_pcrel ? (_Unwind_Internal_Ptr) u : base);
      if (encoding & DW_EH_PE_indirect)
        result = *(_Unwind_Internal_Ptr*) result;
    }

  }

  *val = result;
  return p;

}
예제 #18
0
파일: exception.c 프로젝트: a565109863/src
PERSONALITY_FUNCTION (int version,
		      _Unwind_Action actions,
		      _Unwind_Exception_Class exception_class,
		      struct _Unwind_Exception *ue_header,
		      struct _Unwind_Context *context)
#endif
{
  struct ObjcException *xh = (struct ObjcException *) ue_header;

  struct lsda_header_info info;
  const unsigned char *language_specific_data;
  const unsigned char *action_record;
  const unsigned char *p;
  _Unwind_Ptr landing_pad, ip;
  int handler_switch_value;
  int saw_cleanup = 0, saw_handler;
  void *return_object;
  int foreign_exception;
  int ip_before_insn = 0;

#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;

  foreign_exception = 0;

  ip = (_Unwind_Ptr) ue_header;
  _Unwind_SetGR(context, 12, ip);
#else
  /* Interface version check.  */
  if (version != 1)
    return _URC_FATAL_PHASE1_ERROR;
  foreign_exception = !(exception_class == __objc_exception_class);
#endif

  /* Shortcut for phase 2 found handler for domestic exception.  */
  if (actions == (_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME)
      && !foreign_exception)
    {
#ifdef __ARM_EABI_UNWINDER__
      handler_switch_value = (int) ue_header->barrier_cache.bitpattern[1];
      landing_pad = (_Unwind_Ptr) ue_header->barrier_cache.bitpattern[3];
#else
      handler_switch_value = xh->handlerSwitchValue;
      landing_pad = xh->landingPad;
#endif
      goto install_context;
    }

  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);
  info.ttype_base = base_of_encoded_value (info.ttype_encoding, context);
#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 = 0;
  handler_switch_value = 0;

#ifdef 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
    {
      _Unwind_Word 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 = 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;
      _Unwind_Word 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 /* SJLJ_EXCEPTIONS  */

  /* If ip is not present in the table, C++ would call terminate.  */
  /* ??? As with Java, it's perhaps better to tweek the LSDA to
     that no-action is mapped to no-entry.  */
  return _URC_CONTINUE_UNWIND;

 found_something:
  saw_cleanup = 0;
  saw_handler = 0;

  if (landing_pad == 0)
    {
      /* If ip is present, and has a null landing pad, there are
	 no cleanups or handlers to be run.  */
    }
  else if (action_record == 0)
    {
      /* If ip is present, has a non-null landing pad, and a null
         action table offset, then there are only cleanups present.
         Cleanups use a zero switch value, as set above.  */
      saw_cleanup = 1;
    }
  else
    {
      /* Otherwise we have a catch handler.  */
      _Unwind_Sword ar_filter, ar_disp;

      while (1)
	{
	  p = action_record;
	  p = read_sleb128 (p, &ar_filter);
	  read_sleb128 (p, &ar_disp);

	  if (ar_filter == 0)
	    {
	      /* Zero filter values are cleanups.  */
	      saw_cleanup = 1;
	    }

	  /* During forced unwinding, we only run cleanups.  With a
	     foreign exception class, we have no class info to match.  */
	  else if ((actions & _UA_FORCE_UNWIND)
		   || foreign_exception)
	    ;

	  else if (ar_filter > 0)
	    {
	      /* Positive filter values are handlers.  */

	      Class catch_type = get_ttype_entry (&info, ar_filter);

	      if (isKindOf (xh->value, catch_type))
		{
		  handler_switch_value = ar_filter;
		  saw_handler = 1;
		  break;
		}
	    }
	  else
	    {
	      /* Negative filter values are exception specifications,
	         which Objective-C does not use.  */
	      abort ();
	    }

	  if (ar_disp == 0)
	    break;
	  action_record = p + ar_disp;
	}
    }

  if (! saw_handler && ! saw_cleanup)
    CONTINUE_UNWINDING;

  if (actions & _UA_SEARCH_PHASE)
    {
      if (!saw_handler)
	CONTINUE_UNWINDING;

      /* For domestic exceptions, we cache data from phase 1 for phase 2.  */
      if (!foreign_exception)
        {
#ifdef __ARM_EABI_UNWIDER__
	  ue_header->barrier_cache.sp = _Unwind_GetGR(context, 13);
	  ue_header->barrier_cache.bitpattern[1]
	    = (_uw) handler_switch_value;
	  ue_header->barrier_cache.bitpattern[3] = (_uw) landing_pad;
#else
          xh->handlerSwitchValue = handler_switch_value;
          xh->landingPad = landing_pad;
#endif
	}
      return _URC_HANDLER_FOUND;
    }

 install_context:
  if (saw_cleanup == 0)
    {
      return_object = xh->value;
      if (!(actions & _UA_SEARCH_PHASE))
	_Unwind_DeleteException(&xh->base);
    }
  
  _Unwind_SetGR (context, __builtin_eh_return_data_regno (0),
		 __builtin_extend_pointer (saw_cleanup ? xh : return_object));
  _Unwind_SetGR (context, __builtin_eh_return_data_regno (1),
		 handler_switch_value);
  _Unwind_SetIP (context, landing_pad);
  return _URC_INSTALL_CONTEXT;
}
예제 #19
0
파일: personality.c 프로젝트: djc/runa
_Unwind_Reason_Code __runa_personality(int version,
  _Unwind_Action actions, _Unwind_Exception_Class exception_class,
  struct _Unwind_Exception *ue_header, struct _Unwind_Context *context) {

  enum found_handler_type {
    found_nothing, found_terminate, found_cleanup, found_handler
  } found_type;

  struct lsda_header_info info;
  const unsigned char *language_specific_data;
  const unsigned char *action_record;
  const unsigned char *p;
  _Unwind_Ptr landing_pad, ip;
  int handler_switch_value;
  void* thrown_ptr = 0;
  bool foreign_exception;
  int ip_before_insn = 0;

  //__cxa_exception* xh = __get_exception_header_from_ue(ue_header);

  // Interface version check.
  if (version != 1)
    return _URC_FATAL_PHASE1_ERROR;

  foreign_exception = exception_class != RUNA_CLASS;

  // Shortcut for phase 2 found handler for domestic exception.
  if (actions == (_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME) && !foreign_exception) {
    restore_caught_exception(ue_header, &handler_switch_value,
                             &language_specific_data, &landing_pad);
    found_type = (landing_pad == 0 ? found_terminate : found_handler);
    goto install_context;
  }

  language_specific_data = (const unsigned char *) _Unwind_GetLanguageSpecificData(context);

  // If no LSDA, then there are no handlers or cleanups.
  if (!language_specific_data)
    return _URC_CONTINUE_UNWIND;

  // Parse the LSDA header.
  p = parse_lsda_header(context, language_specific_data, &info);
  info.ttype_base = base_of_encoded_value(info.ttype_encoding, context);
  ip = _Unwind_GetIPInfo(context, &ip_before_insn);
  //ip = _Unwind_GetIP(context);
  if (!ip_before_insn)
    --ip;

  landing_pad = 0;
  action_record = 0;
  handler_switch_value = 0;

  // 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;
    }

  }

  // If ip is not present in the table, call terminate. This is for
  // a destructor inside a cleanup, or a library routine the compiler
  // was not expecting to throw.
  found_type = found_terminate;
  goto do_something;

 found_something:
  if (landing_pad == 0) {
    // If ip is present, and has a null landing pad, there are
    // no cleanups or handlers to be run.
    found_type = found_nothing;
  } else if (action_record == 0) {
    // If ip is present, has a non-null landing pad, and a null
    // action table offset, then there are only cleanups present.
    // Cleanups use a zero switch value, as set above.
    found_type = found_cleanup;
  } else {

    // Otherwise we have a catch handler or exception specification.
    _sleb128_t ar_filter, ar_disp;
    //const std::type_info* catch_type;
    //_throw_typet* throw_type;
    bool saw_cleanup = false;
    bool saw_handler = false;

    {
      //thrown_ptr = __get_object_from_ue(ue_header);
      //throw_type = __get_exception_header_from_obj(thrown_ptr)->exceptionType;
    }

    while (1) {

      p = action_record;
      p = read_sleb128(p, &ar_filter);
      read_sleb128(p, &ar_disp);

      if (ar_filter == 0) {
        // Zero filter values are cleanups.
        saw_cleanup = true;
      } else if (ar_filter > 0) {

        // Positive filter values are handlers.
        //catch_type = get_ttype_entry(&info, ar_filter);
        //printf("positive filter value -- handler found\n");
        saw_handler = true;
        break;

        // Null catch type is a catch-all handler; we can catch foreign
        // exceptions with this. Otherwise we must match types.

        //if (!catch_type || (throw_type &&
        //                    get_adjusted_ptr(catch_type, throw_type, &thrown_ptr))) {
        //  saw_handler = true;
        //  break;
        //}

      } else {

        printf("negative filter value -- exception spec\n");
        // Negative filter values are exception specifications.
        // ??? How do foreign exceptions fit in?  As far as I can
        // see we can't match because there's no __cxa_exception
        // object to stuff bits in for __cxa_call_unexpected to use.
        // Allow them iff the exception spec is non-empty.  I.e.
        // a throw() specification results in __unexpected.

        //if ((throw_type && !(actions & _UA_FORCE_UNWIND) && !foreign_exception) ?
        //    !check_exception_spec(&info, throw_type, thrown_ptr, ar_filter) :
        //    empty_exception_spec(&info, ar_filter)) {
        //  saw_handler = true;
        //  break;
        //}

      }

      if (ar_disp == 0)
        break;
      action_record = p + ar_disp;

    }

    if (saw_handler) {
      handler_switch_value = ar_filter;
      found_type = found_handler;
    } else {
      found_type = (saw_cleanup ? found_cleanup : found_nothing);
    }

  }

 do_something:

   if (found_type == found_nothing)
     return _URC_CONTINUE_UNWIND;

  if (actions & _UA_SEARCH_PHASE) {

    if (found_type == found_cleanup)
      return _URC_CONTINUE_UNWIND;

    // For domestic exceptions, we cache data from phase 1 for phase 2.
    if (!foreign_exception) {
      save_caught_exception(ue_header, handler_switch_value,
                            language_specific_data, landing_pad);
    }

    return _URC_HANDLER_FOUND;
  }

 install_context:

  // We can't use any of the cxa routines with foreign exceptions,
  // because they all expect ue_header to be a struct __cxa_exception.
  // So in that case, call terminate or unexpected directly.
  if ((actions & _UA_FORCE_UNWIND) || foreign_exception) {

    if (found_type == found_terminate)
      abort(); // std::terminate();
    else if (handler_switch_value < 0) {
      printf("WTF\n");
      //__try
      //  { std::unexpected (); }
      //__catch(...)
      //  { std::terminate (); }
    }

  } else {

    if (found_type == found_terminate)
      abort(); //__cxa_call_terminate(ue_header);

    // Cache the TType base value for __cxa_call_unexpected, as we won't
    // have an _Unwind_Context then.
    if (handler_switch_value < 0) {
      parse_lsda_header(context, language_specific_data, &info);
      info.ttype_base = base_of_encoded_value(info.ttype_encoding, context);
      //xh->catchTemp = base_of_encoded_value (info.ttype_encoding, context);
    }

  }

  /* For targets with pointers smaller than the word size, we must extend the
     pointer, and this extension is target dependent.  */
  _Unwind_SetGR(context, __builtin_eh_return_data_regno(0), __builtin_extend_pointer(ue_header));
  _Unwind_SetGR(context, __builtin_eh_return_data_regno(1), handler_switch_value);
  _Unwind_SetIP(context, landing_pad);
  return _URC_INSTALL_CONTEXT;

}
예제 #20
0
파일: raise-gcc.c 프로젝트: OrkFyurer/gcc
static void
get_action_description_for (_Unwind_Ptr ip,
                            _Unwind_Exception *uw_exception,
                            _Unwind_Action uw_phase,
                            region_descriptor *region,
                            action_descriptor *action)
{
  _GNAT_Exception *gnat_exception = (_GNAT_Exception *) uw_exception;

  /* Search the call site table first, which may get us a landing pad as well
     as the head of an action record list.  */
  get_call_site_action_for (ip, region, action);
  db_action_for (action, ip);

  /* If there is not even a call_site entry, we are done.  */
  if (action->kind == nothing)
    return;

  /* Otherwise, check what we have at the place of the call site.  */

  /* No landing pad => no cleanups or handlers.  */
  if (action->landing_pad == 0)
    {
      action->kind = nothing;
      return;
    }

  /* Landing pad + null table entry => only cleanups.  */
  else if (action->table_entry == 0)
    {
      action->kind = cleanup;
      action->ttype_filter = cleanup_filter;
      /* The filter initialization is not strictly necessary, as cleanup-only
	 landing pads don't look at the filter value.  It is there to ensure
	 we don't pass random values and so trigger potential confusion when
	 installing the context later on.  */
      return;
    }

  /* Landing pad + Table entry => handlers + possible cleanups.  */
  else
    {
      const unsigned char * p = action->table_entry;

      _sleb128_t ar_filter, ar_disp;

      action->kind = nothing;

      while (1)
	{
	  p = read_sleb128 (p, &ar_filter);
	  read_sleb128 (p, &ar_disp);
	  /* Don't assign p here, as it will be incremented by ar_disp
	     below.  */

	  /* Null filters are for cleanups. */
	  if (ar_filter == cleanup_filter)
	    {
	      action->kind = cleanup;
	      action->ttype_filter = cleanup_filter;
	      /* The filter initialization is required here, to ensure
		 the target landing pad branches to the cleanup code if
		 we happen not to find a matching handler.  */
	    }

	  /* Positive filters are for regular handlers.  */
	  else if (ar_filter > 0)
	    {
              /* Do not catch an exception if the _UA_FORCE_UNWIND flag is
                 passed (to follow the ABI).  */
              if (!(uw_phase & _UA_FORCE_UNWIND))
                {
		  enum action_kind act;

                  /* See if the filter we have is for an exception which
                     matches the one we are propagating.  */
                  _Unwind_Ptr choice = get_ttype_entry_for (region, ar_filter);

		  act = is_handled_by (choice, gnat_exception);
                  if (act != nothing)
                    {
		      action->kind = act;
                      action->ttype_filter = ar_filter;
                      return;
                    }
                }
	    }

	  /* Negative filter values are for C++ exception specifications.
	     Should not be there for Ada :/  */
	  else
	    db (DB_ERR, "========> Err, filter < 0 for Ada/dwarf\n");

	  if (ar_disp == 0)
	    return;

	  p += ar_disp;
	}
    }
}
예제 #21
0
bfd_boolean
_bfd_elf_discard_section_eh_frame
   (bfd *abfd, struct bfd_link_info *info, asection *sec,
    bfd_boolean (*reloc_symbol_deleted_p) (bfd_vma, void *),
    struct elf_reloc_cookie *cookie)
{
  bfd_byte *ehbuf = NULL, *buf;
  bfd_byte *last_cie, *last_fde;
  struct cie_header hdr;
  struct cie cie;
  struct elf_link_hash_table *htab;
  struct eh_frame_hdr_info *hdr_info;
  struct eh_frame_sec_info *sec_info = NULL;
  unsigned int leb128_tmp;
  unsigned int cie_usage_count, last_cie_ndx, i, offset;
  unsigned int make_relative, make_lsda_relative;
  bfd_size_type new_size;
  unsigned int ptr_size;

  if (sec->_raw_size == 0)
    {
      /* This file does not contain .eh_frame information.  */
      return FALSE;
    }

  if ((sec->output_section != NULL
       && bfd_is_abs_section (sec->output_section)))
    {
      /* At least one of the sections is being discarded from the
         link, so we should just ignore them.  */
      return FALSE;
    }

  htab = elf_hash_table (info);
  hdr_info = &htab->eh_info;

  /* Read the frame unwind information from abfd.  */

  ehbuf = bfd_malloc (sec->_raw_size);
  if (ehbuf == NULL)
    goto free_no_table;

  if (! bfd_get_section_contents (abfd, sec, ehbuf, 0, sec->_raw_size))
    goto free_no_table;

  if (sec->_raw_size >= 4
      && bfd_get_32 (abfd, ehbuf) == 0
      && cookie->rel == cookie->relend)
    {
      /* Empty .eh_frame section.  */
      free (ehbuf);
      return FALSE;
    }

  /* If .eh_frame section size doesn't fit into int, we cannot handle
     it (it would need to use 64-bit .eh_frame format anyway).  */
  if (sec->_raw_size != (unsigned int) sec->_raw_size)
    goto free_no_table;

  ptr_size = (elf_elfheader (abfd)->e_ident[EI_CLASS]
	      == ELFCLASS64) ? 8 : 4;
  buf = ehbuf;
  last_cie = NULL;
  last_cie_ndx = 0;
  memset (&cie, 0, sizeof (cie));
  cie_usage_count = 0;
  new_size = sec->_raw_size;
  make_relative = hdr_info->last_cie.make_relative;
  make_lsda_relative = hdr_info->last_cie.make_lsda_relative;
  sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info)
			  + 99 * sizeof (struct eh_cie_fde));
  if (sec_info == NULL)
    goto free_no_table;
  sec_info->alloced = 100;

#define ENSURE_NO_RELOCS(buf)				\
  if (cookie->rel < cookie->relend			\
      && (cookie->rel->r_offset				\
	  < (bfd_size_type) ((buf) - ehbuf))		\
      && cookie->rel->r_info != 0)			\
    goto free_no_table

#define SKIP_RELOCS(buf)				\
  while (cookie->rel < cookie->relend			\
         && (cookie->rel->r_offset			\
	     < (bfd_size_type) ((buf) - ehbuf)))	\
    cookie->rel++

#define GET_RELOC(buf)					\
  ((cookie->rel < cookie->relend			\
    && (cookie->rel->r_offset				\
        == (bfd_size_type) ((buf) - ehbuf)))		\
   ? cookie->rel : NULL)

  for (;;)
    {
      unsigned char *aug;

      if (sec_info->count == sec_info->alloced)
	{
	  sec_info = bfd_realloc (sec_info,
				  sizeof (struct eh_frame_sec_info)
				  + (sec_info->alloced + 99)
				     * sizeof (struct eh_cie_fde));
	  if (sec_info == NULL)
	    goto free_no_table;

	  memset (&sec_info->entry[sec_info->alloced], 0,
		  100 * sizeof (struct eh_cie_fde));
	  sec_info->alloced += 100;
	}

      last_fde = buf;
      /* If we are at the end of the section, we still need to decide
	 on whether to output or discard last encountered CIE (if any).  */
      if ((bfd_size_type) (buf - ehbuf) == sec->_raw_size)
	hdr.id = (unsigned int) -1;
      else
	{
	  if ((bfd_size_type) (buf + 4 - ehbuf) > sec->_raw_size)
	    /* No space for CIE/FDE header length.  */
	    goto free_no_table;

	  hdr.length = bfd_get_32 (abfd, buf);
	  if (hdr.length == 0xffffffff)
	    /* 64-bit .eh_frame is not supported.  */
	    goto free_no_table;
	  buf += 4;
	  if ((bfd_size_type) (buf - ehbuf) + hdr.length > sec->_raw_size)
	    /* CIE/FDE not contained fully in this .eh_frame input section.  */
	    goto free_no_table;

	  sec_info->entry[sec_info->count].offset = last_fde - ehbuf;
	  sec_info->entry[sec_info->count].size = 4 + hdr.length;

	  if (hdr.length == 0)
	    {
	      /* CIE with length 0 must be only the last in the section.  */
	      if ((bfd_size_type) (buf - ehbuf) < sec->_raw_size)
		goto free_no_table;
	      ENSURE_NO_RELOCS (buf);
	      sec_info->count++;
	      /* Now just finish last encountered CIE processing and break
		 the loop.  */
	      hdr.id = (unsigned int) -1;
	    }
	  else
	    {
	      hdr.id = bfd_get_32 (abfd, buf);
	      buf += 4;
	      if (hdr.id == (unsigned int) -1)
		goto free_no_table;
	    }
	}

      if (hdr.id == 0 || hdr.id == (unsigned int) -1)
	{
	  unsigned int initial_insn_length;

	  /* CIE  */
	  if (last_cie != NULL)
	    {
	      /* Now check if this CIE is identical to the last CIE,
		 in which case we can remove it provided we adjust
		 all FDEs.  Also, it can be removed if we have removed
		 all FDEs using it.  */
	      if ((!info->relocatable
		   && hdr_info->last_cie_sec
		   && (sec->output_section
		       == hdr_info->last_cie_sec->output_section)
		   && cie_compare (&cie, &hdr_info->last_cie) == 0)
		  || cie_usage_count == 0)
		{
		  new_size -= cie.hdr.length + 4;
		  sec_info->entry[last_cie_ndx].removed = 1;
		  sec_info->entry[last_cie_ndx].sec = hdr_info->last_cie_sec;
		  sec_info->entry[last_cie_ndx].new_offset
		    = hdr_info->last_cie_offset;
		}
	      else
		{
		  hdr_info->last_cie = cie;
		  hdr_info->last_cie_sec = sec;
		  hdr_info->last_cie_offset = last_cie - ehbuf;
		  sec_info->entry[last_cie_ndx].make_relative
		    = cie.make_relative;
		  sec_info->entry[last_cie_ndx].make_lsda_relative
		    = cie.make_lsda_relative;
		  sec_info->entry[last_cie_ndx].per_encoding_relative
		    = (cie.per_encoding & 0x70) == DW_EH_PE_pcrel;
		}
	    }

	  if (hdr.id == (unsigned int) -1)
	    break;

	  last_cie_ndx = sec_info->count;
	  sec_info->entry[sec_info->count].cie = 1;

	  cie_usage_count = 0;
	  memset (&cie, 0, sizeof (cie));
	  cie.hdr = hdr;
	  cie.version = *buf++;

	  /* Cannot handle unknown versions.  */
	  if (cie.version != 1)
	    goto free_no_table;
	  if (strlen (buf) > sizeof (cie.augmentation) - 1)
	    goto free_no_table;

	  strcpy (cie.augmentation, buf);
	  buf = strchr (buf, '\0') + 1;
	  ENSURE_NO_RELOCS (buf);
	  if (buf[0] == 'e' && buf[1] == 'h')
	    {
	      /* GCC < 3.0 .eh_frame CIE */
	      /* We cannot merge "eh" CIEs because __EXCEPTION_TABLE__
		 is private to each CIE, so we don't need it for anything.
		 Just skip it.  */
	      buf += ptr_size;
	      SKIP_RELOCS (buf);
	    }
	  read_uleb128 (cie.code_align, buf);
	  read_sleb128 (cie.data_align, buf);
	  /* Note - in DWARF2 the return address column is an unsigned byte.
	     In DWARF3 it is a ULEB128.  We are following DWARF3.  For most
	     ports this will not matter as the value will be less than 128.
	     For the others (eg FRV, SH, MMIX, IA64) they need a fixed GCC
	     which conforms to the DWARF3 standard.  */
	  read_uleb128 (cie.ra_column, buf);
	  ENSURE_NO_RELOCS (buf);
	  cie.lsda_encoding = DW_EH_PE_omit;
	  cie.fde_encoding = DW_EH_PE_omit;
	  cie.per_encoding = DW_EH_PE_omit;
	  aug = cie.augmentation;
	  if (aug[0] != 'e' || aug[1] != 'h')
	    {
	      if (*aug == 'z')
		{
		  aug++;
		  read_uleb128 (cie.augmentation_size, buf);
	  	  ENSURE_NO_RELOCS (buf);
		}

	      while (*aug != '\0')
		switch (*aug++)
		  {
		  case 'L':
		    cie.lsda_encoding = *buf++;
		    ENSURE_NO_RELOCS (buf);
		    if (get_DW_EH_PE_width (cie.lsda_encoding, ptr_size) == 0)
		      goto free_no_table;
		    break;
		  case 'R':
		    cie.fde_encoding = *buf++;
		    ENSURE_NO_RELOCS (buf);
		    if (get_DW_EH_PE_width (cie.fde_encoding, ptr_size) == 0)
		      goto free_no_table;
		    break;
		  case 'P':
		    {
		      int per_width;

		      cie.per_encoding = *buf++;
		      per_width = get_DW_EH_PE_width (cie.per_encoding,
						      ptr_size);
		      if (per_width == 0)
			goto free_no_table;
		      if ((cie.per_encoding & 0xf0) == DW_EH_PE_aligned)
			buf = (ehbuf
			       + ((buf - ehbuf + per_width - 1)
				  & ~((bfd_size_type) per_width - 1)));
		      ENSURE_NO_RELOCS (buf);
		      /* Ensure we have a reloc here, against
			 a global symbol.  */
		      if (GET_RELOC (buf) != NULL)
			{
			  unsigned long r_symndx;

#ifdef BFD64
			  if (ptr_size == 8)
			    r_symndx = ELF64_R_SYM (cookie->rel->r_info);
			  else
#endif
			    r_symndx = ELF32_R_SYM (cookie->rel->r_info);
			  if (r_symndx >= cookie->locsymcount)
			    {
			      struct elf_link_hash_entry *h;

			      r_symndx -= cookie->extsymoff;
			      h = cookie->sym_hashes[r_symndx];

			      while (h->root.type == bfd_link_hash_indirect
				     || h->root.type == bfd_link_hash_warning)
				h = (struct elf_link_hash_entry *)
				    h->root.u.i.link;

			      cie.personality = h;
			    }
			  cookie->rel++;
			}
		      buf += per_width;
		    }
		    break;
		  default:
		    /* Unrecognized augmentation. Better bail out.  */
		    goto free_no_table;
		  }
	    }

	  /* For shared libraries, try to get rid of as many RELATIVE relocs
	     as possible.  */
          if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_relative_eh_frame
		  (abfd, info, sec))
	      && (cie.fde_encoding & 0xf0) == DW_EH_PE_absptr)
	    cie.make_relative = 1;

	  if (info->shared
	      && (get_elf_backend_data (abfd)
		  ->elf_backend_can_make_lsda_relative_eh_frame
		  (abfd, info, sec))
	      && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr)
	    cie.make_lsda_relative = 1;

	  /* If FDE encoding was not specified, it defaults to
	     DW_EH_absptr.  */
	  if (cie.fde_encoding == DW_EH_PE_omit)
	    cie.fde_encoding = DW_EH_PE_absptr;

	  initial_insn_length = cie.hdr.length - (buf - last_fde - 4);
	  if (initial_insn_length <= 50)
	    {
	      cie.initial_insn_length = initial_insn_length;
	      memcpy (cie.initial_instructions, buf, initial_insn_length);
	    }
	  buf += initial_insn_length;
	  ENSURE_NO_RELOCS (buf);
	  last_cie = last_fde;
	}
      else
	{
	  /* Ensure this FDE uses the last CIE encountered.  */
	  if (last_cie == NULL
	      || hdr.id != (unsigned int) (buf - 4 - last_cie))
	    goto free_no_table;

	  ENSURE_NO_RELOCS (buf);
	  if (GET_RELOC (buf) == NULL)
	    /* This should not happen.  */
	    goto free_no_table;
	  if ((*reloc_symbol_deleted_p) (buf - ehbuf, cookie))
	    {
	      /* This is a FDE against a discarded section.  It should
		 be deleted.  */
	      new_size -= hdr.length + 4;
	      sec_info->entry[sec_info->count].removed = 1;
	    }
	  else
	    {
	      if (info->shared
		  && (((cie.fde_encoding & 0xf0) == DW_EH_PE_absptr
		       && cie.make_relative == 0)
		      || (cie.fde_encoding & 0xf0) == DW_EH_PE_aligned))
		{
		  /* If a shared library uses absolute pointers
		     which we cannot turn into PC relative,
		     don't create the binary search table,
		     since it is affected by runtime relocations.  */
		  hdr_info->table = FALSE;
		}
	      cie_usage_count++;
	      hdr_info->fde_count++;
	    }
	  if (cie.lsda_encoding != DW_EH_PE_omit)
	    {
	      unsigned int dummy;

	      aug = buf;
	      buf += 2 * get_DW_EH_PE_width (cie.fde_encoding, ptr_size);
	      if (cie.augmentation[0] == 'z')
		read_uleb128 (dummy, buf);
	      /* If some new augmentation data is added before LSDA
		 in FDE augmentation area, this need to be adjusted.  */
	      sec_info->entry[sec_info->count].lsda_offset = (buf - aug);
	    }
	  buf = last_fde + 4 + hdr.length;
	  SKIP_RELOCS (buf);
	}

      sec_info->entry[sec_info->count].fde_encoding = cie.fde_encoding;
      sec_info->entry[sec_info->count].lsda_encoding = cie.lsda_encoding;
      sec_info->count++;
    }

  elf_section_data (sec)->sec_info = sec_info;
  sec->sec_info_type = ELF_INFO_TYPE_EH_FRAME;

  /* Ok, now we can assign new offsets.  */
  offset = 0;
  last_cie_ndx = 0;
  for (i = 0; i < sec_info->count; i++)
    {
      if (! sec_info->entry[i].removed)
	{
	  sec_info->entry[i].new_offset = offset;
	  offset += sec_info->entry[i].size;
	  if (sec_info->entry[i].cie)
	    {
	      last_cie_ndx = i;
	      make_relative = sec_info->entry[i].make_relative;
	      make_lsda_relative = sec_info->entry[i].make_lsda_relative;
	    }
	  else
	    {
	      sec_info->entry[i].make_relative = make_relative;
	      sec_info->entry[i].make_lsda_relative = make_lsda_relative;
	      sec_info->entry[i].per_encoding_relative = 0;
	    }
	}
      else if (sec_info->entry[i].cie && sec_info->entry[i].sec == sec)
	{
	  /* Need to adjust new_offset too.  */
	  BFD_ASSERT (sec_info->entry[last_cie_ndx].offset
		      == sec_info->entry[i].new_offset);
	  sec_info->entry[i].new_offset
	    = sec_info->entry[last_cie_ndx].new_offset;
	}
    }
  if (hdr_info->last_cie_sec == sec)
    {
      BFD_ASSERT (sec_info->entry[last_cie_ndx].offset
		  == hdr_info->last_cie_offset);
      hdr_info->last_cie_offset = sec_info->entry[last_cie_ndx].new_offset;
    }

  /* FIXME: Currently it is not possible to shrink sections to zero size at
     this point, so build a fake minimal CIE.  */
  if (new_size == 0)
    new_size = 16;

  /* Shrink the sec as needed.  */
  sec->_cooked_size = new_size;
  if (sec->_cooked_size == 0)
    sec->flags |= SEC_EXCLUDE;

  free (ehbuf);
  return new_size != sec->_raw_size;

free_no_table:
  if (ehbuf)
    free (ehbuf);
  if (sec_info)
    free (sec_info);
  hdr_info->table = FALSE;
  hdr_info->last_cie.hdr.length = 0;
  return FALSE;
}