[RFC PATCH v4 08/15] GDB: Allow DWARF expression evaluation to use regcache

Luis Machado luis.machado@arm.com
Mon Dec 16 16:56:04 GMT 2024


On 11/2/24 02:56, Thiago Jung Bauermann wrote:
> Currently, expression evaluation is done in the context of a frame.
> However, for variable-size registers we will need to evaluate
> expressions when no frame is available, but we do have a regcache.
> Therefore, allow passing a regcache to dwarf2_evaluate_property.
> 
> This requires adding a regcache parameter to resolve_dynamic_type and
> its internal functions.
> 
> Also, this means that a DWARF expression may not be associated with an
> objfile, so when it needs a gdbarch it may not be possible to get the
> one from the objfile.  The solution is to add an m_gdbarch member to
> dwarf_expr_context, and make it point to the gdbarch of either the
> objfile, frame or regcache associated with the expression.
> 
> Simon suggested using GDB Agent Expressions rather than DWARF
> expressions to encode the register length. I will try it out, and if it
> works then this patch can be dropped.

Between using DWARF expressions and agent expressions, I suppose DWARF would
be the most promising as it is properly documented. Agent expressions are a
bit obscure at this point I think, and IIRC gdb-specific. But if it provides
something simpler, might be worth a shot.

> ---
>  gdb/dwarf2/expr.c  | 63 +++++++++++++++++++++++++++++++------
>  gdb/dwarf2/expr.h  | 17 +++++++++-
>  gdb/dwarf2/frame.c |  2 +-
>  gdb/dwarf2/loc.c   | 41 +++++++++++++++++-------
>  gdb/dwarf2/loc.h   |  2 ++
>  gdb/findvar.c      | 17 ++++++++++
>  gdb/frame.c        |  3 +-
>  gdb/gdbtypes.c     | 77 ++++++++++++++++++++++++++--------------------
>  gdb/gdbtypes.h     |  5 ++-
>  gdb/gnu-v3-abi.c   |  2 +-
>  gdb/value.h        |  3 ++
>  11 files changed, 173 insertions(+), 59 deletions(-)
> 
> diff --git a/gdb/dwarf2/expr.c b/gdb/dwarf2/expr.c
> index 5ad17eaaaff8..4a667dbd8107 100644
> --- a/gdb/dwarf2/expr.c
> +++ b/gdb/dwarf2/expr.c
> @@ -56,6 +56,20 @@ ensure_have_frame (const frame_info_ptr &frame, const char *op_name)
>  		 _("%s evaluation requires a frame."), op_name);
>  }
>  
> +/* Ensure that either a FRAME or a REGCACHE is defined, throw an exception
> +   otherwise.  */
> +
> +static void
> +ensure_have_frame_or_regcache (const frame_info_ptr &frame,
> +			       const reg_buffer *regcache,
> +			       const char *op_name)
> +{
> +  if (frame == nullptr && regcache == nullptr)
> +    throw_error (GENERIC_ERROR,
> +		 _("%s evaluation requires a frame or register cache."),
> +		 op_name);
> +}
> +
>  /* Ensure that a PER_CU is defined and throw an exception otherwise.  */
>  
>  static void
> @@ -86,6 +100,16 @@ read_addr_from_reg (const frame_info_ptr &frame, int reg)
>    return address_from_register (regnum, frame);
>  }
>  
> +/* See expr.h.  */
> +
> +CORE_ADDR
> +read_addr_from_reg (reg_buffer *regcache, int reg)
> +{
> +  int regnum = dwarf_reg_to_regnum_or_error (regcache->arch (), reg);
> +
> +  return address_from_register (regnum, regcache);
> +}
> +
>  struct piece_closure
>  {
>    /* Reference count.  */
> @@ -690,7 +714,8 @@ sect_variable_value (sect_offset sect_off,
>  struct type *
>  dwarf_expr_context::address_type () const
>  {
> -  gdbarch *arch = this->m_per_objfile->objfile->arch ();
> +  gdbarch *arch = (m_gdbarch == nullptr ? this->m_per_objfile->objfile->arch ()
> +		   : m_gdbarch);
>    dwarf_gdbarch_types *types = dwarf_arch_cookie.get (arch);
>    if (types == nullptr)
>      types = dwarf_arch_cookie.emplace (arch);
> @@ -720,9 +745,11 @@ dwarf_expr_context::address_type () const
>  /* Create a new context for the expression evaluator.  */
>  
>  dwarf_expr_context::dwarf_expr_context (dwarf2_per_objfile *per_objfile,
> -					int addr_size)
> +					int addr_size,
> +					gdbarch *gdbarch)
>  : m_addr_size (addr_size),
> -  m_per_objfile (per_objfile)
> +  m_per_objfile (per_objfile),
> +  m_gdbarch (gdbarch)
>  {
>  }
>  
> @@ -915,7 +942,6 @@ dwarf_expr_context::fetch_result (struct type *type, struct type *subobj_type,
>  				  LONGEST subobj_offset, bool as_lval)
>  {
>    value *retval = nullptr;
> -  gdbarch *arch = this->m_per_objfile->objfile->arch ();
>  
>    if (type == nullptr)
>      type = address_type ();
> @@ -948,6 +974,9 @@ dwarf_expr_context::fetch_result (struct type *type, struct type *subobj_type,
>      }
>    else
>      {
> +      gdbarch *arch = (m_gdbarch == nullptr ? this->m_per_objfile->objfile->arch ()
> +		       : m_gdbarch);
> +
>        /* If AS_LVAL is false, means that the implicit conversion
>  	 from a location description to value is expected.  */
>        if (!as_lval)
> @@ -1077,12 +1106,14 @@ dwarf_expr_context::fetch_result (struct type *type, struct type *subobj_type,
>  value *
>  dwarf_expr_context::evaluate (const gdb_byte *addr, size_t len, bool as_lval,
>  			      dwarf2_per_cu_data *per_cu, const frame_info_ptr &frame,
> +			      reg_buffer *regcache,
>  			      const struct property_addr_info *addr_info,
>  			      struct type *type, struct type *subobj_type,
>  			      LONGEST subobj_offset)
>  {
>    this->m_per_cu = per_cu;
>    this->m_frame = frame;
> +  this->m_regcache = regcache;
>    this->m_addr_info = addr_info;
>  
>    eval (addr, len);
> @@ -1149,7 +1180,8 @@ get_signed_type (struct gdbarch *gdbarch, struct type *type)
>  CORE_ADDR
>  dwarf_expr_context::fetch_address (int n)
>  {
> -  gdbarch *arch = this->m_per_objfile->objfile->arch ();
> +  gdbarch *arch = (m_gdbarch == nullptr ? this->m_per_objfile->objfile->arch ()
> +		   : m_gdbarch);
>    value *result_val = fetch (n);
>    bfd_endian byte_order = gdbarch_byte_order (arch);
>    ULONGEST result;
> @@ -1493,7 +1525,8 @@ void
>  dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
>  				      const gdb_byte *op_end)
>  {
> -  gdbarch *arch = this->m_per_objfile->objfile->arch ();
> +  gdbarch *arch = (this->m_gdbarch ? this->m_gdbarch
> +		   : this->m_per_objfile->objfile->arch ());
>    bfd_endian byte_order = gdbarch_byte_order (arch);
>    /* Old-style "untyped" DWARF values need special treatment in a
>       couple of places, specifically DW_OP_mod and DW_OP_shr.  We need
> @@ -1784,9 +1817,14 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
>  	case DW_OP_breg31:
>  	  {
>  	    op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
> -	    ensure_have_frame (this->m_frame, "DW_OP_breg");
> +	    ensure_have_frame_or_regcache (this->m_frame, this->m_regcache,
> +					   "DW_OP_breg");
> +
> +	    if (this->m_frame != nullptr)
> +	      result = read_addr_from_reg (this->m_frame, op - DW_OP_breg0);
> +	    else
> +	      result = read_addr_from_reg (this->m_regcache, op - DW_OP_breg0);
>  
> -	    result = read_addr_from_reg (this->m_frame, op - DW_OP_breg0);
>  	    result += offset;
>  	    result_val = value_from_ulongest (address_type, result);
>  	  }
> @@ -1795,9 +1833,14 @@ dwarf_expr_context::execute_stack_op (const gdb_byte *op_ptr,
>  	  {
>  	    op_ptr = safe_read_uleb128 (op_ptr, op_end, &reg);
>  	    op_ptr = safe_read_sleb128 (op_ptr, op_end, &offset);
> -	    ensure_have_frame (this->m_frame, "DW_OP_bregx");
> +	    ensure_have_frame_or_regcache (this->m_frame, this->m_regcache,
> +					   "DW_OP_bregx");
> +
> +	    if (this->m_frame != nullptr)
> +	      result = read_addr_from_reg (this->m_frame, reg);
> +	    else
> +	      result = read_addr_from_reg (this->m_regcache, reg);
>  
> -	    result = read_addr_from_reg (this->m_frame, reg);
>  	    result += offset;
>  	    result_val = value_from_ulongest (address_type, result);
>  	  }
> diff --git a/gdb/dwarf2/expr.h b/gdb/dwarf2/expr.h
> index b02cc5316406..9a3c92650664 100644
> --- a/gdb/dwarf2/expr.h
> +++ b/gdb/dwarf2/expr.h
> @@ -115,12 +115,14 @@ struct dwarf_stack_value
>    bool in_stack_memory;
>  };
>  
> +struct reg_buffer;
> +
>  /* The expression evaluator works with a dwarf_expr_context, describing
>     its current state and its callbacks.  */
>  struct dwarf_expr_context
>  {
>    dwarf_expr_context (dwarf2_per_objfile *per_objfile,
> -		      int addr_size);
> +		      int addr_size, gdbarch *gdbarch = nullptr);
>    virtual ~dwarf_expr_context () = default;
>  
>    void push_address (CORE_ADDR value, bool in_stack_memory);
> @@ -128,6 +130,8 @@ struct dwarf_expr_context
>    /* Evaluate the expression at ADDR (LEN bytes long) in a given PER_CU
>       and FRAME context.
>  
> +     If FRAME is nullptr, then registers are read from REGCACHE.
> +
>       AS_LVAL defines if the returned struct value is expected to be a
>       value (false) or a location description (true).
>  
> @@ -138,6 +142,7 @@ struct dwarf_expr_context
>       memory addresses with the passed in buffer.  */
>    value *evaluate (const gdb_byte *addr, size_t len, bool as_lval,
>  		   dwarf2_per_cu_data *per_cu, const frame_info_ptr &frame,
> +		   reg_buffer *regcache,
>  		   const struct property_addr_info *addr_info = nullptr,
>  		   struct type *type = nullptr,
>  		   struct type *subobj_type = nullptr,
> @@ -198,6 +203,12 @@ struct dwarf_expr_context
>    /* Frame information used for the evaluation.  */
>    frame_info_ptr m_frame = nullptr;
>  
> +  /* Register cache used for the evaluation, in case there's no frame.  */
> +  reg_buffer *m_regcache = nullptr;
> +
> +  /* gdbarch used for the evaluation.  */
> +  gdbarch *m_gdbarch = nullptr;
> +
>    /* Compilation unit used for the evaluation.  */
>    dwarf2_per_cu_data *m_per_cu = nullptr;
>  
> @@ -258,6 +269,10 @@ struct dwarf_expr_context
>     read as an address in a given FRAME.  */
>  CORE_ADDR read_addr_from_reg (const frame_info_ptr &frame, int reg);
>  
> +/* Return the value of register number REG (a DWARF register number),
> +   read as an address in a given REGCACHE.  */
> +CORE_ADDR read_addr_from_reg (reg_buffer *regcache, int reg);
> +
>  void dwarf_expr_require_composition (const gdb_byte *, const gdb_byte *,
>  				     const char *);
>  
> diff --git a/gdb/dwarf2/frame.c b/gdb/dwarf2/frame.c
> index 841d2d4a2fec..3da9551a7ace 100644
> --- a/gdb/dwarf2/frame.c
> +++ b/gdb/dwarf2/frame.c
> @@ -237,7 +237,7 @@ execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
>    scoped_value_mark free_values;
>  
>    ctx.push_address (initial, initial_in_stack_memory);
> -  value *result_val = ctx.evaluate (exp, len, true, nullptr, this_frame);
> +  value *result_val = ctx.evaluate (exp, len, true, nullptr, this_frame, nullptr);
>  
>    if (result_val->lval () == lval_memory)
>      return result_val->address ();
> diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
> index d5153862a01d..d7fa58047cdd 100644
> --- a/gdb/dwarf2/loc.c
> +++ b/gdb/dwarf2/loc.c
> @@ -1518,7 +1518,7 @@ dwarf2_evaluate_loc_desc_full (struct type *type, const frame_info_ptr &frame,
>    try
>      {
>        retval = ctx.evaluate (data, size, as_lval, per_cu, frame, nullptr,
> -			     type, subobj_type, subobj_byte_offset);
> +			     nullptr, type, subobj_type, subobj_byte_offset);
>      }
>    catch (const gdb_exception_error &ex)
>      {
> @@ -1565,11 +1565,12 @@ dwarf2_evaluate_loc_desc (struct type *type, const frame_info_ptr &frame,
>  					per_objfile, NULL, 0, as_lval);
>  }
>  
> -/* Evaluates a dwarf expression and stores the result in VAL,
> -   expecting that the dwarf expression only produces a single
> -   CORE_ADDR.  FRAME is the frame in which the expression is
> -   evaluated.  ADDR_STACK is a context (location of a variable) and
> -   might be needed to evaluate the location expression.
> +/* Evaluates a dwarf expression and stores the result in VAL, expecting
> +   that the dwarf expression only produces a single CORE_ADDR.  FRAME is
> +   the frame in which the expression is evaluated.  If FRAME is nullptr,
> +   then registers are read from REGCACHE instead.  ADDR_STACK is a context
> +   (location of a variable) and might be needed to evaluate the location
> +   expression.
>  
>     PUSH_VALUES is an array of values to be pushed to the expression stack
>     before evaluation starts.  PUSH_VALUES[0] is pushed first, then
> @@ -1580,6 +1581,7 @@ dwarf2_evaluate_loc_desc (struct type *type, const frame_info_ptr &frame,
>  static int
>  dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
>  			   const frame_info_ptr &frame,
> +			   reg_buffer *regcache,
>  			   const struct property_addr_info *addr_stack,
>  			   CORE_ADDR *valp,
>  			   gdb::array_view<CORE_ADDR> push_values,
> @@ -1590,7 +1592,21 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
>  
>    dwarf2_per_objfile *per_objfile = dlbaton->per_objfile;
>    dwarf2_per_cu_data *per_cu = dlbaton->per_cu;
> -  dwarf_expr_context ctx (per_objfile, per_cu->addr_size ());
> +  gdbarch *gdbarch;
> +
> +  if (per_objfile != nullptr)
> +    gdbarch = per_objfile->objfile->arch ();
> +  else if (frame != nullptr)
> +    gdbarch = get_frame_arch (frame);
> +  else
> +    {
> +      gdb_assert (regcache != nullptr);
> +      gdbarch = regcache->arch ();
> +    }
> +
> +  int addr_size = (per_cu == nullptr ? gdbarch_addr_bit (gdbarch) / 8
> +		   : per_cu->addr_size ());
> +  dwarf_expr_context ctx (per_objfile, addr_size, gdbarch);
>  
>    value *result;
>    scoped_value_mark free_values;
> @@ -1602,7 +1618,7 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
>    try
>      {
>        result = ctx.evaluate (dlbaton->data, dlbaton->size,
> -			     true, per_cu, frame, addr_stack);
> +			     true, per_cu, frame, regcache, addr_stack);
>      }
>    catch (const gdb_exception_error &ex)
>      {
> @@ -1641,6 +1657,7 @@ dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton *dlbaton,
>  bool
>  dwarf2_evaluate_property (const dynamic_prop *prop,
>  			  const frame_info_ptr &initial_frame,
> +			  reg_buffer *regcache,
>  			  const property_addr_info *addr_stack,
>  			  CORE_ADDR *value,
>  			  gdb::array_view<CORE_ADDR> push_values)
> @@ -1654,7 +1671,8 @@ dwarf2_evaluate_property (const dynamic_prop *prop,
>    scoped_restore_current_language save_language;
>    frame_info_ptr frame = initial_frame;
>  
> -  if (frame == NULL && has_stack_frames ())
> +  /* Only try to get a frame if no regcache was provided.  */
> +  if (frame == nullptr && regcache == nullptr && has_stack_frames ())
>      frame = get_selected_frame (NULL);
>  
>    switch (prop->kind ())
> @@ -1665,8 +1683,9 @@ dwarf2_evaluate_property (const dynamic_prop *prop,
>  	gdb_assert (baton->property_type != NULL);
>  
>  	bool is_reference = baton->locexpr.is_reference;
> -	if (dwarf2_locexpr_baton_eval (&baton->locexpr, frame, addr_stack,
> -				       value, push_values, &is_reference))
> +	if (dwarf2_locexpr_baton_eval (&baton->locexpr, frame, regcache,
> +				       addr_stack, value, push_values,
> +				       &is_reference))
>  	  {
>  	    if (is_reference)
>  	      {
> diff --git a/gdb/dwarf2/loc.h b/gdb/dwarf2/loc.h
> index 4fb743618e7c..679c4962d137 100644
> --- a/gdb/dwarf2/loc.h
> +++ b/gdb/dwarf2/loc.h
> @@ -118,8 +118,10 @@ struct property_addr_info
>     etc.  This means the during evaluation PUSH_VALUES[0] will be at the
>     bottom of the stack.  */
>  
> +struct reg_buffer;
>  bool dwarf2_evaluate_property (const struct dynamic_prop *prop,
>  			       const frame_info_ptr &frame,
> +			       reg_buffer *regcache,
>  			       const property_addr_info *addr_stack,
>  			       CORE_ADDR *value,
>  			       gdb::array_view<CORE_ADDR> push_values = {});
> diff --git a/gdb/findvar.c b/gdb/findvar.c
> index f7760aa61ca9..d65bf2fc278c 100644
> --- a/gdb/findvar.c
> +++ b/gdb/findvar.c
> @@ -656,3 +656,20 @@ address_from_register (int regnum, const frame_info_ptr &frame)
>  
>    return value_as_address (v.get ());
>  }
> +
> +/* Return contents of register REGNUM in REGCACHE as address.
> +   Will abort if register value is not available.  */
> +
> +CORE_ADDR
> +address_from_register (int regnum, reg_buffer *regcache)
> +{
> +  if (regcache->get_register_status (regnum) != REG_VALID)
> +    throw_error (NOT_AVAILABLE_ERROR, _("register %d is not available"),
> +		 regnum);
> +
> +  gdb_byte buffer[sizeof (CORE_ADDR)];
> +  regcache->raw_collect (regnum, buffer);
> +
> +  type *type = builtin_type (regcache->arch ())->builtin_data_ptr;
> +  return extract_typed_address (buffer, type);
> +}
> diff --git a/gdb/frame.c b/gdb/frame.c
> index 2c1ea012191b..663ff7fa773b 100644
> --- a/gdb/frame.c
> +++ b/gdb/frame.c
> @@ -3175,7 +3175,8 @@ frame_follow_static_link (const frame_info_ptr &initial_frame)
>  
>    CORE_ADDR upper_frame_base;
>  
> -  if (!dwarf2_evaluate_property (static_link, initial_frame, NULL, &upper_frame_base))
> +  if (!dwarf2_evaluate_property (static_link, initial_frame, nullptr, nullptr,
> +				 &upper_frame_base))
>      return {};
>  
>    /* Now climb up the stack frame until we reach the frame we are interested
> diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
> index 2a3aea229cb0..ea8bad4e826c 100644
> --- a/gdb/gdbtypes.c
> +++ b/gdb/gdbtypes.c
> @@ -2146,7 +2146,7 @@ is_dynamic_type (struct type *type)
>  
>  static struct type *resolve_dynamic_type_internal
>    (struct type *type, struct property_addr_info *addr_stack,
> -   const frame_info_ptr &frame, bool top_level);
> +   const frame_info_ptr &frame, reg_buffer *regcache, bool top_level);
>  
>  /* Given a dynamic range type (dyn_range_type) and a stack of
>     struct property_addr_info elements, return a static version
> @@ -2168,6 +2168,7 @@ static struct type *
>  resolve_dynamic_range (struct type *dyn_range_type,
>  		       struct property_addr_info *addr_stack,
>  		       const frame_info_ptr &frame,
> +		       reg_buffer *regcache,
>  		       int rank, bool resolve_p = true)
>  {
>    CORE_ADDR value;
> @@ -2180,7 +2181,7 @@ resolve_dynamic_range (struct type *dyn_range_type,
>    const struct dynamic_prop *prop = &dyn_range_type->bounds ()->low;
>    if (resolve_p)
>      {
> -      if (dwarf2_evaluate_property (prop, frame, addr_stack, &value,
> +      if (dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value,
>  				    { (CORE_ADDR) rank }))
>  	low_bound.set_const_val (value);
>        else if (prop->kind () == PROP_UNDEFINED)
> @@ -2194,7 +2195,7 @@ resolve_dynamic_range (struct type *dyn_range_type,
>    prop = &dyn_range_type->bounds ()->high;
>    if (resolve_p)
>      {
> -      if (dwarf2_evaluate_property (prop, frame, addr_stack, &value,
> +      if (dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value,
>  				    { (CORE_ADDR) rank }))
>  	{
>  	  high_bound.set_const_val (value);
> @@ -2213,8 +2214,8 @@ resolve_dynamic_range (struct type *dyn_range_type,
>  
>    bool byte_stride_p = dyn_range_type->bounds ()->flag_is_byte_stride;
>    prop = &dyn_range_type->bounds ()->stride;
> -  if (resolve_p && dwarf2_evaluate_property (prop, frame, addr_stack, &value,
> -					     { (CORE_ADDR) rank }))
> +  if (resolve_p && dwarf2_evaluate_property (prop, frame, regcache, addr_stack,
> +					     &value, { (CORE_ADDR) rank }))
>      {
>        stride.set_const_val (value);
>  
> @@ -2236,7 +2237,7 @@ resolve_dynamic_range (struct type *dyn_range_type,
>  
>    static_target_type
>      = resolve_dynamic_type_internal (dyn_range_type->target_type (),
> -				     addr_stack, frame, false);
> +				     addr_stack, frame, regcache, false);
>    LONGEST bias = dyn_range_type->bounds ()->bias;
>    type_allocator alloc (dyn_range_type);
>    static_range_type = create_range_type_with_stride
> @@ -2270,6 +2271,7 @@ static struct type *
>  resolve_dynamic_array_or_string_1 (struct type *type,
>  				   struct property_addr_info *addr_stack,
>  				   const frame_info_ptr &frame,
> +				   reg_buffer *regcache,
>  				   int rank, bool resolve_p)
>  {
>    CORE_ADDR value;
> @@ -2299,7 +2301,7 @@ resolve_dynamic_array_or_string_1 (struct type *type,
>       dimension of the array.  */
>    prop = TYPE_ALLOCATED_PROP (type);
>    if (prop != NULL && resolve_p
> -      && dwarf2_evaluate_property (prop, frame, addr_stack, &value))
> +      && dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value))
>      {
>        prop->set_const_val (value);
>        if (value == 0)
> @@ -2308,7 +2310,7 @@ resolve_dynamic_array_or_string_1 (struct type *type,
>  
>    prop = TYPE_ASSOCIATED_PROP (type);
>    if (prop != NULL && resolve_p
> -      && dwarf2_evaluate_property (prop, frame, addr_stack, &value))
> +      && dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value))
>      {
>        prop->set_const_val (value);
>        if (value == 0)
> @@ -2317,14 +2319,15 @@ resolve_dynamic_array_or_string_1 (struct type *type,
>  
>    range_type = check_typedef (type->index_type ());
>    range_type
> -    = resolve_dynamic_range (range_type, addr_stack, frame, rank, resolve_p);
> +    = resolve_dynamic_range (range_type, addr_stack, frame, regcache, rank,
> +			     resolve_p);
>  
>    ary_dim = check_typedef (type->target_type ());
>    if (ary_dim != NULL && ary_dim->code () == TYPE_CODE_ARRAY)
>      {
>        ary_dim = copy_type (ary_dim);
>        elt_type = resolve_dynamic_array_or_string_1 (ary_dim, addr_stack,
> -						    frame, rank - 1,
> +						    frame, regcache, rank - 1,
>  						    resolve_p);
>      }
>    else if (ary_dim != nullptr && ary_dim->code () == TYPE_CODE_STRING)
> @@ -2355,7 +2358,7 @@ resolve_dynamic_array_or_string_1 (struct type *type,
>  	 Fortran, and hope that this doesn't cause problems for anyone
>  	 else.  */
>        elt_type = resolve_dynamic_type_internal (type->target_type (),
> -						addr_stack, frame, 0);
> +						addr_stack, frame, regcache, 0);
>      }
>    else
>      elt_type = type->target_type ();
> @@ -2365,7 +2368,7 @@ resolve_dynamic_array_or_string_1 (struct type *type,
>      prop = nullptr;
>    if (prop != NULL && resolve_p)
>      {
> -      if (dwarf2_evaluate_property (prop, frame, addr_stack, &value))
> +      if (dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value))
>  	{
>  	  type->remove_dyn_prop (DYN_PROP_BYTE_STRIDE);
>  	  bit_stride = (unsigned int) (value * 8);
> @@ -2397,7 +2400,8 @@ resolve_dynamic_array_or_string_1 (struct type *type,
>  static struct type *
>  resolve_dynamic_array_or_string (struct type *type,
>  				 struct property_addr_info *addr_stack,
> -				 const frame_info_ptr &frame)
> +				 const frame_info_ptr &frame,
> +				 reg_buffer *regcache)
>  {
>    CORE_ADDR value;
>    int rank = 0;
> @@ -2411,7 +2415,7 @@ resolve_dynamic_array_or_string (struct type *type,
>  
>    /* Resolve the rank property to get rank value.  */
>    struct dynamic_prop *prop = TYPE_RANK_PROP (type);
> -  if (dwarf2_evaluate_property (prop, frame, addr_stack, &value))
> +  if (dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value))
>      {
>        prop->set_const_val (value);
>        rank = value;
> @@ -2479,8 +2483,8 @@ resolve_dynamic_array_or_string (struct type *type,
>       reduce the rank by 1 here.  */
>    --rank;
>  
> -  return resolve_dynamic_array_or_string_1 (type, addr_stack, frame, rank,
> -					    true);
> +  return resolve_dynamic_array_or_string_1 (type, addr_stack, frame, regcache,
> +					    rank, true);
>  }
>  
>  /* Resolve dynamic bounds of members of the union TYPE to static
> @@ -2490,7 +2494,8 @@ resolve_dynamic_array_or_string (struct type *type,
>  static struct type *
>  resolve_dynamic_union (struct type *type,
>  		       struct property_addr_info *addr_stack,
> -		       const frame_info_ptr &frame)
> +		       const frame_info_ptr &frame,
> +		       reg_buffer *regcache)
>  {
>    struct type *resolved_type;
>    int i;
> @@ -2508,7 +2513,7 @@ resolve_dynamic_union (struct type *type,
>  	continue;
>  
>        t = resolve_dynamic_type_internal (resolved_type->field (i).type (),
> -					 addr_stack, frame, false);
> +					 addr_stack, frame, regcache, false);
>        resolved_type->field (i).set_type (t);
>  
>        struct type *real_type = check_typedef (t);
> @@ -2682,7 +2687,8 @@ compute_variant_fields (struct type *type,
>  static struct type *
>  resolve_dynamic_struct (struct type *type,
>  			struct property_addr_info *addr_stack,
> -			const frame_info_ptr &frame)
> +			const frame_info_ptr &frame,
> +			reg_buffer *regcache)
>  {
>    struct type *resolved_type;
>    int i;
> @@ -2725,8 +2731,8 @@ resolve_dynamic_struct (struct type *type,
>  	  prop.set_locexpr (&baton);
>  
>  	  CORE_ADDR addr;
> -	  if (dwarf2_evaluate_property (&prop, frame, addr_stack, &addr,
> -					{addr_stack->addr}))
> +	  if (dwarf2_evaluate_property (&prop, frame, regcache, addr_stack,
> +					&addr, {addr_stack->addr}))
>  	    resolved_type->field (i).set_loc_bitpos
>  	      (TARGET_CHAR_BIT * (addr - addr_stack->addr));
>  	}
> @@ -2752,7 +2758,7 @@ resolve_dynamic_struct (struct type *type,
>  
>        resolved_type->field (i).set_type
>  	(resolve_dynamic_type_internal (resolved_type->field (i).type (),
> -					&pinfo, frame, false));
> +					&pinfo, frame, regcache, false));
>        gdb_assert (resolved_type->field (i).loc_kind ()
>  		  == FIELD_LOC_KIND_BITPOS);
>  
> @@ -2798,6 +2804,7 @@ static struct type *
>  resolve_dynamic_type_internal (struct type *type,
>  			       struct property_addr_info *addr_stack,
>  			       const frame_info_ptr &frame,
> +			       reg_buffer *regcache,
>  			       bool top_level)
>  {
>    struct type *real_type = check_typedef (type);
> @@ -2811,7 +2818,7 @@ resolve_dynamic_type_internal (struct type *type,
>    std::optional<CORE_ADDR> type_length;
>    prop = TYPE_DYNAMIC_LENGTH (type);
>    if (prop != NULL
> -      && dwarf2_evaluate_property (prop, frame, addr_stack, &value))
> +      && dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value))
>      type_length = value;
>  
>    if (type->code () == TYPE_CODE_TYPEDEF)
> @@ -2819,7 +2826,7 @@ resolve_dynamic_type_internal (struct type *type,
>        resolved_type = copy_type (type);
>        resolved_type->set_target_type
>  	(resolve_dynamic_type_internal (type->target_type (), addr_stack,
> -					frame, top_level));
> +					frame, regcache, top_level));
>      }
>    else
>      {
> @@ -2849,8 +2856,8 @@ resolve_dynamic_type_internal (struct type *type,
>  	      {
>  		resolved_type = copy_type (type);
>  		resolved_type->set_target_type
> -		  (resolve_dynamic_type_internal (type->target_type (),
> -						  &pinfo, frame, true));
> +		  (resolve_dynamic_type_internal (type->target_type (), &pinfo,
> +						  frame, regcache, true));
>  	      }
>  	    break;
>  	  }
> @@ -2860,7 +2867,7 @@ resolve_dynamic_type_internal (struct type *type,
>  	     treated as one here.  */
>  	case TYPE_CODE_ARRAY:
>  	  resolved_type = resolve_dynamic_array_or_string (type, addr_stack,
> -							   frame);
> +							   frame, regcache);
>  	  break;
>  
>  	case TYPE_CODE_RANGE:
> @@ -2869,15 +2876,18 @@ resolve_dynamic_type_internal (struct type *type,
>  	     this rank value is not actually required for the resolution of
>  	     the dynamic range, otherwise, we'd be resolving this range
>  	     within the context of a dynamic array.  */
> -	  resolved_type = resolve_dynamic_range (type, addr_stack, frame, 0);
> +	  resolved_type = resolve_dynamic_range (type, addr_stack, frame,
> +						 regcache, 0);
>  	  break;
>  
>  	case TYPE_CODE_UNION:
> -	  resolved_type = resolve_dynamic_union (type, addr_stack, frame);
> +	  resolved_type = resolve_dynamic_union (type, addr_stack, frame,
> +						 regcache);
>  	  break;
>  
>  	case TYPE_CODE_STRUCT:
> -	  resolved_type = resolve_dynamic_struct (type, addr_stack, frame);
> +	  resolved_type = resolve_dynamic_struct (type, addr_stack, frame,
> +						  regcache);
>  	  break;
>  	}
>      }
> @@ -2894,7 +2904,7 @@ resolve_dynamic_type_internal (struct type *type,
>    /* Resolve data_location attribute.  */
>    prop = TYPE_DATA_LOCATION (resolved_type);
>    if (prop != NULL
> -      && dwarf2_evaluate_property (prop, frame, addr_stack, &value))
> +      && dwarf2_evaluate_property (prop, frame, regcache, addr_stack, &value))
>      {
>        /* Start of Fortran hack.  See comment in f-lang.h for what is going
>  	 on here.*/
> @@ -2915,7 +2925,8 @@ struct type *
>  resolve_dynamic_type (struct type *type,
>  		      gdb::array_view<const gdb_byte> valaddr,
>  		      CORE_ADDR addr,
> -		      const frame_info_ptr *in_frame)
> +		      const frame_info_ptr *in_frame,
> +		      reg_buffer *regcache)
>  {
>    struct property_addr_info pinfo
>      = {check_typedef (type), valaddr, addr, NULL};
> @@ -2924,7 +2935,7 @@ resolve_dynamic_type (struct type *type,
>    if (in_frame != nullptr)
>      frame = *in_frame;
>  
> -  return resolve_dynamic_type_internal (type, &pinfo, frame, true);
> +  return resolve_dynamic_type_internal (type, &pinfo, frame, regcache, true);
>  }
>  
>  /* See gdbtypes.h  */
> diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
> index f80bd7e071a3..514af300de3b 100644
> --- a/gdb/gdbtypes.h
> +++ b/gdb/gdbtypes.h
> @@ -2625,9 +2625,12 @@ extern CORE_ADDR get_pointer_type_max (struct type *);
>     have a different type when resolved (depending on the contents of
>     memory).  In this situation, 'is_dynamic_type' will still return
>     true for the return value of this function.  */
> +
> +struct reg_buffer;
>  extern struct type *resolve_dynamic_type
>    (struct type *type, gdb::array_view<const gdb_byte> valaddr,
> -   CORE_ADDR addr, const frame_info_ptr *frame = nullptr);
> +   CORE_ADDR addr, const frame_info_ptr *frame = nullptr,
> +   reg_buffer *regcache = nullptr);
>  
>  /* * Predicate if the type has dynamic values, which are not resolved yet.
>     See the caveat in 'resolve_dynamic_type' to understand a scenario
> diff --git a/gdb/gnu-v3-abi.c b/gdb/gnu-v3-abi.c
> index aefbee542703..5cc0d1d2d4f4 100644
> --- a/gdb/gnu-v3-abi.c
> +++ b/gdb/gnu-v3-abi.c
> @@ -493,7 +493,7 @@ gnuv3_baseclass_offset (struct type *type, int index,
>        addr_stack.next = nullptr;
>  
>        CORE_ADDR result;
> -      if (dwarf2_evaluate_property (&prop, nullptr, &addr_stack, &result,
> +      if (dwarf2_evaluate_property (&prop, nullptr, nullptr, &addr_stack, &result,
>  				    {addr_stack.addr}))
>  	return (int) (result - addr_stack.addr);
>      }
> diff --git a/gdb/value.h b/gdb/value.h
> index 13cfb007aa2c..802a49066288 100644
> --- a/gdb/value.h
> +++ b/gdb/value.h
> @@ -1133,6 +1133,9 @@ extern struct value *value_from_register (struct type *type, int regnum,
>  
>  extern CORE_ADDR address_from_register (int regnum,
>  					const frame_info_ptr &frame);
> +struct reg_buffer;
> +extern CORE_ADDR address_from_register (int regnum,
> +					reg_buffer *regcache);
>  
>  extern struct value *value_of_variable (struct symbol *var,
>  					const struct block *b);



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